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pmap.c revision 1.335
      1 /*	$NetBSD: pmap.c,v 1.335 2016/07/14 15:51:41 skrll Exp $	*/
      2 
      3 /*
      4  * Copyright 2003 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Steve C. Woodford for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *      This product includes software developed for the NetBSD Project by
     20  *      Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 /*
     39  * Copyright (c) 2002-2003 Wasabi Systems, Inc.
     40  * Copyright (c) 2001 Richard Earnshaw
     41  * Copyright (c) 2001-2002 Christopher Gilbert
     42  * All rights reserved.
     43  *
     44  * 1. Redistributions of source code must retain the above copyright
     45  *    notice, this list of conditions and the following disclaimer.
     46  * 2. Redistributions in binary form must reproduce the above copyright
     47  *    notice, this list of conditions and the following disclaimer in the
     48  *    documentation and/or other materials provided with the distribution.
     49  * 3. The name of the company nor the name of the author may be used to
     50  *    endorse or promote products derived from this software without specific
     51  *    prior written permission.
     52  *
     53  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     54  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     55  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     56  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     57  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     58  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     59  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     63  * SUCH DAMAGE.
     64  */
     65 
     66 /*-
     67  * Copyright (c) 1999 The NetBSD Foundation, Inc.
     68  * All rights reserved.
     69  *
     70  * This code is derived from software contributed to The NetBSD Foundation
     71  * by Charles M. Hannum.
     72  *
     73  * Redistribution and use in source and binary forms, with or without
     74  * modification, are permitted provided that the following conditions
     75  * are met:
     76  * 1. Redistributions of source code must retain the above copyright
     77  *    notice, this list of conditions and the following disclaimer.
     78  * 2. Redistributions in binary form must reproduce the above copyright
     79  *    notice, this list of conditions and the following disclaimer in the
     80  *    documentation and/or other materials provided with the distribution.
     81  *
     82  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     83  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     84  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     85  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     86  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     87  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     88  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     89  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     90  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     91  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     92  * POSSIBILITY OF SUCH DAMAGE.
     93  */
     94 
     95 /*
     96  * Copyright (c) 1994-1998 Mark Brinicombe.
     97  * Copyright (c) 1994 Brini.
     98  * All rights reserved.
     99  *
    100  * This code is derived from software written for Brini by Mark Brinicombe
    101  *
    102  * Redistribution and use in source and binary forms, with or without
    103  * modification, are permitted provided that the following conditions
    104  * are met:
    105  * 1. Redistributions of source code must retain the above copyright
    106  *    notice, this list of conditions and the following disclaimer.
    107  * 2. Redistributions in binary form must reproduce the above copyright
    108  *    notice, this list of conditions and the following disclaimer in the
    109  *    documentation and/or other materials provided with the distribution.
    110  * 3. All advertising materials mentioning features or use of this software
    111  *    must display the following acknowledgement:
    112  *	This product includes software developed by Mark Brinicombe.
    113  * 4. The name of the author may not be used to endorse or promote products
    114  *    derived from this software without specific prior written permission.
    115  *
    116  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
    117  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    118  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
    119  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
    120  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
    121  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    122  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    123  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    124  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
    125  *
    126  * RiscBSD kernel project
    127  *
    128  * pmap.c
    129  *
    130  * Machine dependent vm stuff
    131  *
    132  * Created      : 20/09/94
    133  */
    134 
    135 /*
    136  * armv6 and VIPT cache support by 3am Software Foundry,
    137  * Copyright (c) 2007 Microsoft
    138  */
    139 
    140 /*
    141  * Performance improvements, UVM changes, overhauls and part-rewrites
    142  * were contributed by Neil A. Carson <neil (at) causality.com>.
    143  */
    144 
    145 /*
    146  * Overhauled again to speedup the pmap, use MMU Domains so that L1 tables
    147  * can be shared, and re-work the KVM layout, by Steve Woodford of Wasabi
    148  * Systems, Inc.
    149  *
    150  * There are still a few things outstanding at this time:
    151  *
    152  *   - There are some unresolved issues for MP systems:
    153  *
    154  *     o The L1 metadata needs a lock, or more specifically, some places
    155  *       need to acquire an exclusive lock when modifying L1 translation
    156  *       table entries.
    157  *
    158  *     o When one cpu modifies an L1 entry, and that L1 table is also
    159  *       being used by another cpu, then the latter will need to be told
    160  *       that a tlb invalidation may be necessary. (But only if the old
    161  *       domain number in the L1 entry being over-written is currently
    162  *       the active domain on that cpu). I guess there are lots more tlb
    163  *       shootdown issues too...
    164  *
    165  *     o If the vector_page is at 0x00000000 instead of in kernel VA space,
    166  *       then MP systems will lose big-time because of the MMU domain hack.
    167  *       The only way this can be solved (apart from moving the vector
    168  *       page to 0xffff0000) is to reserve the first 1MB of user address
    169  *       space for kernel use only. This would require re-linking all
    170  *       applications so that the text section starts above this 1MB
    171  *       boundary.
    172  *
    173  *     o Tracking which VM space is resident in the cache/tlb has not yet
    174  *       been implemented for MP systems.
    175  *
    176  *     o Finally, there is a pathological condition where two cpus running
    177  *       two separate processes (not lwps) which happen to share an L1
    178  *       can get into a fight over one or more L1 entries. This will result
    179  *       in a significant slow-down if both processes are in tight loops.
    180  */
    181 
    182 /*
    183  * Special compilation symbols
    184  * PMAP_DEBUG		- Build in pmap_debug_level code
    185  */
    186 
    187 /* Include header files */
    188 
    189 #include "opt_arm_debug.h"
    190 #include "opt_cpuoptions.h"
    191 #include "opt_pmap_debug.h"
    192 #include "opt_ddb.h"
    193 #include "opt_lockdebug.h"
    194 #include "opt_multiprocessor.h"
    195 
    196 #ifdef MULTIPROCESSOR
    197 #define _INTR_PRIVATE
    198 #endif
    199 
    200 #include <sys/param.h>
    201 #include <sys/types.h>
    202 #include <sys/kernel.h>
    203 #include <sys/systm.h>
    204 #include <sys/proc.h>
    205 #include <sys/intr.h>
    206 #include <sys/pool.h>
    207 #include <sys/kmem.h>
    208 #include <sys/cdefs.h>
    209 #include <sys/cpu.h>
    210 #include <sys/sysctl.h>
    211 #include <sys/bus.h>
    212 #include <sys/atomic.h>
    213 #include <sys/kernhist.h>
    214 
    215 #include <uvm/uvm.h>
    216 #include <uvm/pmap/pmap_pvt.h>
    217 
    218 #include <arm/locore.h>
    219 
    220 __KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.335 2016/07/14 15:51:41 skrll Exp $");
    221 
    222 //#define PMAP_DEBUG
    223 #ifdef PMAP_DEBUG
    224 
    225 /* XXX need to get rid of all refs to this */
    226 int pmap_debug_level = 0;
    227 
    228 /*
    229  * for switching to potentially finer grained debugging
    230  */
    231 #define	PDB_FOLLOW	0x0001
    232 #define	PDB_INIT	0x0002
    233 #define	PDB_ENTER	0x0004
    234 #define	PDB_REMOVE	0x0008
    235 #define	PDB_CREATE	0x0010
    236 #define	PDB_PTPAGE	0x0020
    237 #define	PDB_GROWKERN	0x0040
    238 #define	PDB_BITS	0x0080
    239 #define	PDB_COLLECT	0x0100
    240 #define	PDB_PROTECT	0x0200
    241 #define	PDB_MAP_L1	0x0400
    242 #define	PDB_BOOTSTRAP	0x1000
    243 #define	PDB_PARANOIA	0x2000
    244 #define	PDB_WIRING	0x4000
    245 #define	PDB_PVDUMP	0x8000
    246 #define	PDB_VAC		0x10000
    247 #define	PDB_KENTER	0x20000
    248 #define	PDB_KREMOVE	0x40000
    249 #define	PDB_EXEC	0x80000
    250 
    251 int debugmap = 1;
    252 int pmapdebug = 0;
    253 #define	NPDEBUG(_lev_,_stat_) \
    254 	if (pmapdebug & (_lev_)) \
    255         	((_stat_))
    256 
    257 #else	/* PMAP_DEBUG */
    258 #define NPDEBUG(_lev_,_stat_) /* Nothing */
    259 #endif	/* PMAP_DEBUG */
    260 
    261 /*
    262  * pmap_kernel() points here
    263  */
    264 static struct pmap	kernel_pmap_store = {
    265 #ifndef ARM_MMU_EXTENDED
    266 	.pm_activated = true,
    267 	.pm_domain = PMAP_DOMAIN_KERNEL,
    268 	.pm_cstate.cs_all = PMAP_CACHE_STATE_ALL,
    269 #endif
    270 };
    271 struct pmap * const	kernel_pmap_ptr = &kernel_pmap_store;
    272 #undef pmap_kernel
    273 #define pmap_kernel()	(&kernel_pmap_store)
    274 #ifdef PMAP_NEED_ALLOC_POOLPAGE
    275 int			arm_poolpage_vmfreelist = VM_FREELIST_DEFAULT;
    276 #endif
    277 
    278 /*
    279  * Pool and cache that pmap structures are allocated from.
    280  * We use a cache to avoid clearing the pm_l2[] array (1KB)
    281  * in pmap_create().
    282  */
    283 static struct pool_cache pmap_cache;
    284 
    285 /*
    286  * Pool of PV structures
    287  */
    288 static struct pool pmap_pv_pool;
    289 static void *pmap_bootstrap_pv_page_alloc(struct pool *, int);
    290 static void pmap_bootstrap_pv_page_free(struct pool *, void *);
    291 static struct pool_allocator pmap_bootstrap_pv_allocator = {
    292 	pmap_bootstrap_pv_page_alloc, pmap_bootstrap_pv_page_free
    293 };
    294 
    295 /*
    296  * Pool and cache of l2_dtable structures.
    297  * We use a cache to avoid clearing the structures when they're
    298  * allocated. (196 bytes)
    299  */
    300 static struct pool_cache pmap_l2dtable_cache;
    301 static vaddr_t pmap_kernel_l2dtable_kva;
    302 
    303 /*
    304  * Pool and cache of L2 page descriptors.
    305  * We use a cache to avoid clearing the descriptor table
    306  * when they're allocated. (1KB)
    307  */
    308 static struct pool_cache pmap_l2ptp_cache;
    309 static vaddr_t pmap_kernel_l2ptp_kva;
    310 static paddr_t pmap_kernel_l2ptp_phys;
    311 
    312 #ifdef PMAPCOUNTERS
    313 #define	PMAP_EVCNT_INITIALIZER(name) \
    314 	EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "pmap", name)
    315 
    316 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
    317 static struct evcnt pmap_ev_vac_clean_one =
    318    PMAP_EVCNT_INITIALIZER("clean page (1 color)");
    319 static struct evcnt pmap_ev_vac_flush_one =
    320    PMAP_EVCNT_INITIALIZER("flush page (1 color)");
    321 static struct evcnt pmap_ev_vac_flush_lots =
    322    PMAP_EVCNT_INITIALIZER("flush page (2+ colors)");
    323 static struct evcnt pmap_ev_vac_flush_lots2 =
    324    PMAP_EVCNT_INITIALIZER("flush page (2+ colors, kmpage)");
    325 EVCNT_ATTACH_STATIC(pmap_ev_vac_clean_one);
    326 EVCNT_ATTACH_STATIC(pmap_ev_vac_flush_one);
    327 EVCNT_ATTACH_STATIC(pmap_ev_vac_flush_lots);
    328 EVCNT_ATTACH_STATIC(pmap_ev_vac_flush_lots2);
    329 
    330 static struct evcnt pmap_ev_vac_color_new =
    331    PMAP_EVCNT_INITIALIZER("new page color");
    332 static struct evcnt pmap_ev_vac_color_reuse =
    333    PMAP_EVCNT_INITIALIZER("ok first page color");
    334 static struct evcnt pmap_ev_vac_color_ok =
    335    PMAP_EVCNT_INITIALIZER("ok page color");
    336 static struct evcnt pmap_ev_vac_color_blind =
    337    PMAP_EVCNT_INITIALIZER("blind page color");
    338 static struct evcnt pmap_ev_vac_color_change =
    339    PMAP_EVCNT_INITIALIZER("change page color");
    340 static struct evcnt pmap_ev_vac_color_erase =
    341    PMAP_EVCNT_INITIALIZER("erase page color");
    342 static struct evcnt pmap_ev_vac_color_none =
    343    PMAP_EVCNT_INITIALIZER("no page color");
    344 static struct evcnt pmap_ev_vac_color_restore =
    345    PMAP_EVCNT_INITIALIZER("restore page color");
    346 
    347 EVCNT_ATTACH_STATIC(pmap_ev_vac_color_new);
    348 EVCNT_ATTACH_STATIC(pmap_ev_vac_color_reuse);
    349 EVCNT_ATTACH_STATIC(pmap_ev_vac_color_ok);
    350 EVCNT_ATTACH_STATIC(pmap_ev_vac_color_blind);
    351 EVCNT_ATTACH_STATIC(pmap_ev_vac_color_change);
    352 EVCNT_ATTACH_STATIC(pmap_ev_vac_color_erase);
    353 EVCNT_ATTACH_STATIC(pmap_ev_vac_color_none);
    354 EVCNT_ATTACH_STATIC(pmap_ev_vac_color_restore);
    355 #endif
    356 
    357 static struct evcnt pmap_ev_mappings =
    358    PMAP_EVCNT_INITIALIZER("pages mapped");
    359 static struct evcnt pmap_ev_unmappings =
    360    PMAP_EVCNT_INITIALIZER("pages unmapped");
    361 static struct evcnt pmap_ev_remappings =
    362    PMAP_EVCNT_INITIALIZER("pages remapped");
    363 
    364 EVCNT_ATTACH_STATIC(pmap_ev_mappings);
    365 EVCNT_ATTACH_STATIC(pmap_ev_unmappings);
    366 EVCNT_ATTACH_STATIC(pmap_ev_remappings);
    367 
    368 static struct evcnt pmap_ev_kernel_mappings =
    369    PMAP_EVCNT_INITIALIZER("kernel pages mapped");
    370 static struct evcnt pmap_ev_kernel_unmappings =
    371    PMAP_EVCNT_INITIALIZER("kernel pages unmapped");
    372 static struct evcnt pmap_ev_kernel_remappings =
    373    PMAP_EVCNT_INITIALIZER("kernel pages remapped");
    374 
    375 EVCNT_ATTACH_STATIC(pmap_ev_kernel_mappings);
    376 EVCNT_ATTACH_STATIC(pmap_ev_kernel_unmappings);
    377 EVCNT_ATTACH_STATIC(pmap_ev_kernel_remappings);
    378 
    379 static struct evcnt pmap_ev_kenter_mappings =
    380    PMAP_EVCNT_INITIALIZER("kenter pages mapped");
    381 static struct evcnt pmap_ev_kenter_unmappings =
    382    PMAP_EVCNT_INITIALIZER("kenter pages unmapped");
    383 static struct evcnt pmap_ev_kenter_remappings =
    384    PMAP_EVCNT_INITIALIZER("kenter pages remapped");
    385 static struct evcnt pmap_ev_pt_mappings =
    386    PMAP_EVCNT_INITIALIZER("page table pages mapped");
    387 
    388 EVCNT_ATTACH_STATIC(pmap_ev_kenter_mappings);
    389 EVCNT_ATTACH_STATIC(pmap_ev_kenter_unmappings);
    390 EVCNT_ATTACH_STATIC(pmap_ev_kenter_remappings);
    391 EVCNT_ATTACH_STATIC(pmap_ev_pt_mappings);
    392 
    393 static struct evcnt pmap_ev_fixup_mod =
    394    PMAP_EVCNT_INITIALIZER("page modification emulations");
    395 static struct evcnt pmap_ev_fixup_ref =
    396    PMAP_EVCNT_INITIALIZER("page reference emulations");
    397 static struct evcnt pmap_ev_fixup_exec =
    398    PMAP_EVCNT_INITIALIZER("exec pages fixed up");
    399 static struct evcnt pmap_ev_fixup_pdes =
    400    PMAP_EVCNT_INITIALIZER("pdes fixed up");
    401 #ifndef ARM_MMU_EXTENDED
    402 static struct evcnt pmap_ev_fixup_ptesync =
    403    PMAP_EVCNT_INITIALIZER("ptesync fixed");
    404 #endif
    405 
    406 EVCNT_ATTACH_STATIC(pmap_ev_fixup_mod);
    407 EVCNT_ATTACH_STATIC(pmap_ev_fixup_ref);
    408 EVCNT_ATTACH_STATIC(pmap_ev_fixup_exec);
    409 EVCNT_ATTACH_STATIC(pmap_ev_fixup_pdes);
    410 #ifndef ARM_MMU_EXTENDED
    411 EVCNT_ATTACH_STATIC(pmap_ev_fixup_ptesync);
    412 #endif
    413 
    414 #ifdef PMAP_CACHE_VIPT
    415 static struct evcnt pmap_ev_exec_mappings =
    416    PMAP_EVCNT_INITIALIZER("exec pages mapped");
    417 static struct evcnt pmap_ev_exec_cached =
    418    PMAP_EVCNT_INITIALIZER("exec pages cached");
    419 
    420 EVCNT_ATTACH_STATIC(pmap_ev_exec_mappings);
    421 EVCNT_ATTACH_STATIC(pmap_ev_exec_cached);
    422 
    423 static struct evcnt pmap_ev_exec_synced =
    424    PMAP_EVCNT_INITIALIZER("exec pages synced");
    425 static struct evcnt pmap_ev_exec_synced_map =
    426    PMAP_EVCNT_INITIALIZER("exec pages synced (MP)");
    427 #ifndef ARM_MMU_EXTENDED
    428 static struct evcnt pmap_ev_exec_synced_unmap =
    429    PMAP_EVCNT_INITIALIZER("exec pages synced (UM)");
    430 static struct evcnt pmap_ev_exec_synced_remap =
    431    PMAP_EVCNT_INITIALIZER("exec pages synced (RM)");
    432 static struct evcnt pmap_ev_exec_synced_clearbit =
    433    PMAP_EVCNT_INITIALIZER("exec pages synced (DG)");
    434 static struct evcnt pmap_ev_exec_synced_kremove =
    435    PMAP_EVCNT_INITIALIZER("exec pages synced (KU)");
    436 #endif
    437 
    438 EVCNT_ATTACH_STATIC(pmap_ev_exec_synced);
    439 EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_map);
    440 #ifndef ARM_MMU_EXTENDED
    441 EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_unmap);
    442 EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_remap);
    443 EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_clearbit);
    444 EVCNT_ATTACH_STATIC(pmap_ev_exec_synced_kremove);
    445 #endif
    446 
    447 static struct evcnt pmap_ev_exec_discarded_unmap =
    448    PMAP_EVCNT_INITIALIZER("exec pages discarded (UM)");
    449 static struct evcnt pmap_ev_exec_discarded_zero =
    450    PMAP_EVCNT_INITIALIZER("exec pages discarded (ZP)");
    451 static struct evcnt pmap_ev_exec_discarded_copy =
    452    PMAP_EVCNT_INITIALIZER("exec pages discarded (CP)");
    453 static struct evcnt pmap_ev_exec_discarded_page_protect =
    454    PMAP_EVCNT_INITIALIZER("exec pages discarded (PP)");
    455 static struct evcnt pmap_ev_exec_discarded_clearbit =
    456    PMAP_EVCNT_INITIALIZER("exec pages discarded (DG)");
    457 static struct evcnt pmap_ev_exec_discarded_kremove =
    458    PMAP_EVCNT_INITIALIZER("exec pages discarded (KU)");
    459 #ifdef ARM_MMU_EXTENDED
    460 static struct evcnt pmap_ev_exec_discarded_modfixup =
    461    PMAP_EVCNT_INITIALIZER("exec pages discarded (MF)");
    462 #endif
    463 
    464 EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_unmap);
    465 EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_zero);
    466 EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_copy);
    467 EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_page_protect);
    468 EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_clearbit);
    469 EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_kremove);
    470 #ifdef ARM_MMU_EXTENDED
    471 EVCNT_ATTACH_STATIC(pmap_ev_exec_discarded_modfixup);
    472 #endif
    473 #endif /* PMAP_CACHE_VIPT */
    474 
    475 static struct evcnt pmap_ev_updates = PMAP_EVCNT_INITIALIZER("updates");
    476 static struct evcnt pmap_ev_collects = PMAP_EVCNT_INITIALIZER("collects");
    477 static struct evcnt pmap_ev_activations = PMAP_EVCNT_INITIALIZER("activations");
    478 
    479 EVCNT_ATTACH_STATIC(pmap_ev_updates);
    480 EVCNT_ATTACH_STATIC(pmap_ev_collects);
    481 EVCNT_ATTACH_STATIC(pmap_ev_activations);
    482 
    483 #define	PMAPCOUNT(x)	((void)(pmap_ev_##x.ev_count++))
    484 #else
    485 #define	PMAPCOUNT(x)	((void)0)
    486 #endif
    487 
    488 /*
    489  * pmap copy/zero page, and mem(5) hook point
    490  */
    491 static pt_entry_t *csrc_pte, *cdst_pte;
    492 static vaddr_t csrcp, cdstp;
    493 #ifdef MULTIPROCESSOR
    494 static size_t cnptes;
    495 #define	cpu_csrc_pte(o)	(csrc_pte + cnptes * cpu_number() + ((o) >> L2_S_SHIFT))
    496 #define	cpu_cdst_pte(o)	(cdst_pte + cnptes * cpu_number() + ((o) >> L2_S_SHIFT))
    497 #define	cpu_csrcp(o)	(csrcp + L2_S_SIZE * cnptes * cpu_number() + (o))
    498 #define	cpu_cdstp(o)	(cdstp + L2_S_SIZE * cnptes * cpu_number() + (o))
    499 #else
    500 #define	cpu_csrc_pte(o)	(csrc_pte + ((o) >> L2_S_SHIFT))
    501 #define	cpu_cdst_pte(o)	(cdst_pte + ((o) >> L2_S_SHIFT))
    502 #define	cpu_csrcp(o)	(csrcp + (o))
    503 #define	cpu_cdstp(o)	(cdstp + (o))
    504 #endif
    505 vaddr_t memhook;			/* used by mem.c & others */
    506 kmutex_t memlock __cacheline_aligned;	/* used by mem.c & others */
    507 kmutex_t pmap_lock __cacheline_aligned;
    508 extern void *msgbufaddr;
    509 int pmap_kmpages;
    510 /*
    511  * Flag to indicate if pmap_init() has done its thing
    512  */
    513 bool pmap_initialized;
    514 
    515 #if defined(ARM_MMU_EXTENDED) && defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS)
    516 /*
    517  * Virtual end of direct-mapped memory
    518  */
    519 vaddr_t pmap_directlimit;
    520 #endif
    521 
    522 /*
    523  * Misc. locking data structures
    524  */
    525 
    526 static inline void
    527 pmap_acquire_pmap_lock(pmap_t pm)
    528 {
    529 	if (pm == pmap_kernel()) {
    530 #ifdef MULTIPROCESSOR
    531 		KERNEL_LOCK(1, NULL);
    532 #endif
    533 	} else {
    534 		mutex_enter(pm->pm_lock);
    535 	}
    536 }
    537 
    538 static inline void
    539 pmap_release_pmap_lock(pmap_t pm)
    540 {
    541 	if (pm == pmap_kernel()) {
    542 #ifdef MULTIPROCESSOR
    543 		KERNEL_UNLOCK_ONE(NULL);
    544 #endif
    545 	} else {
    546 		mutex_exit(pm->pm_lock);
    547 	}
    548 }
    549 
    550 static inline void
    551 pmap_acquire_page_lock(struct vm_page_md *md)
    552 {
    553 	mutex_enter(&pmap_lock);
    554 }
    555 
    556 static inline void
    557 pmap_release_page_lock(struct vm_page_md *md)
    558 {
    559 	mutex_exit(&pmap_lock);
    560 }
    561 
    562 #ifdef DIAGNOSTIC
    563 static inline int
    564 pmap_page_locked_p(struct vm_page_md *md)
    565 {
    566 	return mutex_owned(&pmap_lock);
    567 }
    568 #endif
    569 
    570 
    571 /*
    572  * Metadata for L1 translation tables.
    573  */
    574 #ifndef ARM_MMU_EXTENDED
    575 struct l1_ttable {
    576 	/* Entry on the L1 Table list */
    577 	SLIST_ENTRY(l1_ttable) l1_link;
    578 
    579 	/* Entry on the L1 Least Recently Used list */
    580 	TAILQ_ENTRY(l1_ttable) l1_lru;
    581 
    582 	/* Track how many domains are allocated from this L1 */
    583 	volatile u_int l1_domain_use_count;
    584 
    585 	/*
    586 	 * A free-list of domain numbers for this L1.
    587 	 * We avoid using ffs() and a bitmap to track domains since ffs()
    588 	 * is slow on ARM.
    589 	 */
    590 	uint8_t l1_domain_first;
    591 	uint8_t l1_domain_free[PMAP_DOMAINS];
    592 
    593 	/* Physical address of this L1 page table */
    594 	paddr_t l1_physaddr;
    595 
    596 	/* KVA of this L1 page table */
    597 	pd_entry_t *l1_kva;
    598 };
    599 
    600 /*
    601  * L1 Page Tables are tracked using a Least Recently Used list.
    602  *  - New L1s are allocated from the HEAD.
    603  *  - Freed L1s are added to the TAIl.
    604  *  - Recently accessed L1s (where an 'access' is some change to one of
    605  *    the userland pmaps which owns this L1) are moved to the TAIL.
    606  */
    607 static TAILQ_HEAD(, l1_ttable) l1_lru_list;
    608 static kmutex_t l1_lru_lock __cacheline_aligned;
    609 
    610 /*
    611  * A list of all L1 tables
    612  */
    613 static SLIST_HEAD(, l1_ttable) l1_list;
    614 #endif /* ARM_MMU_EXTENDED */
    615 
    616 /*
    617  * The l2_dtable tracks L2_BUCKET_SIZE worth of L1 slots.
    618  *
    619  * This is normally 16MB worth L2 page descriptors for any given pmap.
    620  * Reference counts are maintained for L2 descriptors so they can be
    621  * freed when empty.
    622  */
    623 struct l2_bucket {
    624 	pt_entry_t *l2b_kva;		/* KVA of L2 Descriptor Table */
    625 	paddr_t l2b_pa;			/* Physical address of same */
    626 	u_short l2b_l1slot;		/* This L2 table's L1 index */
    627 	u_short l2b_occupancy;		/* How many active descriptors */
    628 };
    629 
    630 struct l2_dtable {
    631 	/* The number of L2 page descriptors allocated to this l2_dtable */
    632 	u_int l2_occupancy;
    633 
    634 	/* List of L2 page descriptors */
    635 	struct l2_bucket l2_bucket[L2_BUCKET_SIZE];
    636 };
    637 
    638 /*
    639  * Given an L1 table index, calculate the corresponding l2_dtable index
    640  * and bucket index within the l2_dtable.
    641  */
    642 #define L2_BUCKET_XSHIFT	(L2_BUCKET_XLOG2 - L1_S_SHIFT)
    643 #define L2_BUCKET_XFRAME	(~(vaddr_t)0 << L2_BUCKET_XLOG2)
    644 #define L2_BUCKET_IDX(l1slot)	((l1slot) >> L2_BUCKET_XSHIFT)
    645 #define L2_IDX(l1slot)		(L2_BUCKET_IDX(l1slot) >> L2_BUCKET_LOG2)
    646 #define L2_BUCKET(l1slot)	(L2_BUCKET_IDX(l1slot) & (L2_BUCKET_SIZE - 1))
    647 
    648 __CTASSERT(0x100000000ULL == ((uint64_t)L2_SIZE * L2_BUCKET_SIZE * L1_S_SIZE));
    649 __CTASSERT(L2_BUCKET_XFRAME == ~(L2_BUCKET_XSIZE-1));
    650 
    651 /*
    652  * Given a virtual address, this macro returns the
    653  * virtual address required to drop into the next L2 bucket.
    654  */
    655 #define	L2_NEXT_BUCKET_VA(va)	(((va) & L2_BUCKET_XFRAME) + L2_BUCKET_XSIZE)
    656 
    657 /*
    658  * L2 allocation.
    659  */
    660 #define	pmap_alloc_l2_dtable()		\
    661 	    pool_cache_get(&pmap_l2dtable_cache, PR_NOWAIT)
    662 #define	pmap_free_l2_dtable(l2)		\
    663 	    pool_cache_put(&pmap_l2dtable_cache, (l2))
    664 #define pmap_alloc_l2_ptp(pap)		\
    665 	    ((pt_entry_t *)pool_cache_get_paddr(&pmap_l2ptp_cache,\
    666 	    PR_NOWAIT, (pap)))
    667 
    668 /*
    669  * We try to map the page tables write-through, if possible.  However, not
    670  * all CPUs have a write-through cache mode, so on those we have to sync
    671  * the cache when we frob page tables.
    672  *
    673  * We try to evaluate this at compile time, if possible.  However, it's
    674  * not always possible to do that, hence this run-time var.
    675  */
    676 int	pmap_needs_pte_sync;
    677 
    678 /*
    679  * Real definition of pv_entry.
    680  */
    681 struct pv_entry {
    682 	SLIST_ENTRY(pv_entry) pv_link;	/* next pv_entry */
    683 	pmap_t		pv_pmap;        /* pmap where mapping lies */
    684 	vaddr_t		pv_va;          /* virtual address for mapping */
    685 	u_int		pv_flags;       /* flags */
    686 };
    687 
    688 /*
    689  * Macros to determine if a mapping might be resident in the
    690  * instruction/data cache and/or TLB
    691  */
    692 #if ARM_MMU_V7 > 0 && !defined(ARM_MMU_EXTENDED)
    693 /*
    694  * Speculative loads by Cortex cores can cause TLB entries to be filled even if
    695  * there are no explicit accesses, so there may be always be TLB entries to
    696  * flush.  If we used ASIDs then this would not be a problem.
    697  */
    698 #define	PV_BEEN_EXECD(f)  (((f) & PVF_EXEC) == PVF_EXEC)
    699 #define	PV_BEEN_REFD(f)   (true)
    700 #else
    701 #define	PV_BEEN_EXECD(f)  (((f) & (PVF_REF | PVF_EXEC)) == (PVF_REF | PVF_EXEC))
    702 #define	PV_BEEN_REFD(f)   (((f) & PVF_REF) != 0)
    703 #endif
    704 #define	PV_IS_EXEC_P(f)   (((f) & PVF_EXEC) != 0)
    705 #define	PV_IS_KENTRY_P(f) (((f) & PVF_KENTRY) != 0)
    706 #define	PV_IS_WRITE_P(f)  (((f) & PVF_WRITE) != 0)
    707 
    708 /*
    709  * Local prototypes
    710  */
    711 static bool		pmap_set_pt_cache_mode(pd_entry_t *, vaddr_t, size_t);
    712 static void		pmap_alloc_specials(vaddr_t *, int, vaddr_t *,
    713 			    pt_entry_t **);
    714 static bool		pmap_is_current(pmap_t) __unused;
    715 static bool		pmap_is_cached(pmap_t);
    716 static void		pmap_enter_pv(struct vm_page_md *, paddr_t, struct pv_entry *,
    717 			    pmap_t, vaddr_t, u_int);
    718 static struct pv_entry *pmap_find_pv(struct vm_page_md *, pmap_t, vaddr_t);
    719 static struct pv_entry *pmap_remove_pv(struct vm_page_md *, paddr_t, pmap_t, vaddr_t);
    720 static u_int		pmap_modify_pv(struct vm_page_md *, paddr_t, pmap_t, vaddr_t,
    721 			    u_int, u_int);
    722 
    723 static void		pmap_pinit(pmap_t);
    724 static int		pmap_pmap_ctor(void *, void *, int);
    725 
    726 static void		pmap_alloc_l1(pmap_t);
    727 static void		pmap_free_l1(pmap_t);
    728 #ifndef ARM_MMU_EXTENDED
    729 static void		pmap_use_l1(pmap_t);
    730 #endif
    731 
    732 static struct l2_bucket *pmap_get_l2_bucket(pmap_t, vaddr_t);
    733 static struct l2_bucket *pmap_alloc_l2_bucket(pmap_t, vaddr_t);
    734 static void		pmap_free_l2_bucket(pmap_t, struct l2_bucket *, u_int);
    735 static int		pmap_l2ptp_ctor(void *, void *, int);
    736 static int		pmap_l2dtable_ctor(void *, void *, int);
    737 
    738 static void		pmap_vac_me_harder(struct vm_page_md *, paddr_t, pmap_t, vaddr_t);
    739 #ifdef PMAP_CACHE_VIVT
    740 static void		pmap_vac_me_kpmap(struct vm_page_md *, paddr_t, pmap_t, vaddr_t);
    741 static void		pmap_vac_me_user(struct vm_page_md *, paddr_t, pmap_t, vaddr_t);
    742 #endif
    743 
    744 static void		pmap_clearbit(struct vm_page_md *, paddr_t, u_int);
    745 #ifdef PMAP_CACHE_VIVT
    746 static bool		pmap_clean_page(struct vm_page_md *, bool);
    747 #endif
    748 #ifdef PMAP_CACHE_VIPT
    749 static void		pmap_syncicache_page(struct vm_page_md *, paddr_t);
    750 enum pmap_flush_op {
    751 	PMAP_FLUSH_PRIMARY,
    752 	PMAP_FLUSH_SECONDARY,
    753 	PMAP_CLEAN_PRIMARY
    754 };
    755 #ifndef ARM_MMU_EXTENDED
    756 static void		pmap_flush_page(struct vm_page_md *, paddr_t, enum pmap_flush_op);
    757 #endif
    758 #endif
    759 static void		pmap_page_remove(struct vm_page_md *, paddr_t);
    760 static void		pmap_pv_remove(paddr_t);
    761 
    762 #ifndef ARM_MMU_EXTENDED
    763 static void		pmap_init_l1(struct l1_ttable *, pd_entry_t *);
    764 #endif
    765 static vaddr_t		kernel_pt_lookup(paddr_t);
    766 
    767 
    768 /*
    769  * Misc variables
    770  */
    771 vaddr_t virtual_avail;
    772 vaddr_t virtual_end;
    773 vaddr_t pmap_curmaxkvaddr;
    774 
    775 paddr_t avail_start;
    776 paddr_t avail_end;
    777 
    778 pv_addrqh_t pmap_boot_freeq = SLIST_HEAD_INITIALIZER(&pmap_boot_freeq);
    779 pv_addr_t kernelpages;
    780 pv_addr_t kernel_l1pt;
    781 pv_addr_t systempage;
    782 
    783 /* Function to set the debug level of the pmap code */
    784 
    785 #ifdef PMAP_DEBUG
    786 void
    787 pmap_debug(int level)
    788 {
    789 	pmap_debug_level = level;
    790 	printf("pmap_debug: level=%d\n", pmap_debug_level);
    791 }
    792 #endif	/* PMAP_DEBUG */
    793 
    794 #ifdef PMAP_CACHE_VIPT
    795 #define PMAP_VALIDATE_MD_PAGE(md)	\
    796 	KASSERTMSG(arm_cache_prefer_mask == 0 || (((md)->pvh_attrs & PVF_WRITE) == 0) == ((md)->urw_mappings + (md)->krw_mappings == 0), \
    797 	    "(md) %p: attrs=%#x urw=%u krw=%u", (md), \
    798 	    (md)->pvh_attrs, (md)->urw_mappings, (md)->krw_mappings);
    799 #endif /* PMAP_CACHE_VIPT */
    800 /*
    801  * A bunch of routines to conditionally flush the caches/TLB depending
    802  * on whether the specified pmap actually needs to be flushed at any
    803  * given time.
    804  */
    805 static inline void
    806 pmap_tlb_flush_SE(pmap_t pm, vaddr_t va, u_int flags)
    807 {
    808 #ifdef ARM_MMU_EXTENDED
    809 	pmap_tlb_invalidate_addr(pm, va);
    810 #else
    811 	if (pm->pm_cstate.cs_tlb_id != 0) {
    812 		if (PV_BEEN_EXECD(flags)) {
    813 			cpu_tlb_flushID_SE(va);
    814 		} else if (PV_BEEN_REFD(flags)) {
    815 			cpu_tlb_flushD_SE(va);
    816 		}
    817 	}
    818 #endif /* ARM_MMU_EXTENDED */
    819 }
    820 
    821 static inline void
    822 pmap_tlb_flushID(pmap_t pm)
    823 {
    824 #ifdef ARM_MMU_EXTENDED
    825 	pmap_tlb_asid_release_all(pm);
    826 #else
    827 	if (pm->pm_cstate.cs_tlb_id) {
    828 		cpu_tlb_flushID();
    829 #if ARM_MMU_V7 == 0
    830 		/*
    831 		 * Speculative loads by Cortex cores can cause TLB entries to
    832 		 * be filled even if there are no explicit accesses, so there
    833 		 * may be always be TLB entries to flush.  If we used ASIDs
    834 		 * then it would not be a problem.
    835 		 * This is not true for other CPUs.
    836 		 */
    837 		pm->pm_cstate.cs_tlb = 0;
    838 #endif /* ARM_MMU_V7 */
    839 	}
    840 #endif /* ARM_MMU_EXTENDED */
    841 }
    842 
    843 #ifndef ARM_MMU_EXTENDED
    844 static inline void
    845 pmap_tlb_flushD(pmap_t pm)
    846 {
    847 	if (pm->pm_cstate.cs_tlb_d) {
    848 		cpu_tlb_flushD();
    849 #if ARM_MMU_V7 == 0
    850 		/*
    851 		 * Speculative loads by Cortex cores can cause TLB entries to
    852 		 * be filled even if there are no explicit accesses, so there
    853 		 * may be always be TLB entries to flush.  If we used ASIDs
    854 		 * then it would not be a problem.
    855 		 * This is not true for other CPUs.
    856 		 */
    857 		pm->pm_cstate.cs_tlb_d = 0;
    858 #endif /* ARM_MMU_V7 */
    859 	}
    860 }
    861 #endif /* ARM_MMU_EXTENDED */
    862 
    863 #ifdef PMAP_CACHE_VIVT
    864 static inline void
    865 pmap_cache_wbinv_page(pmap_t pm, vaddr_t va, bool do_inv, u_int flags)
    866 {
    867 	if (PV_BEEN_EXECD(flags) && pm->pm_cstate.cs_cache_id) {
    868 		cpu_idcache_wbinv_range(va, PAGE_SIZE);
    869 	} else if (PV_BEEN_REFD(flags) && pm->pm_cstate.cs_cache_d) {
    870 		if (do_inv) {
    871 			if (flags & PVF_WRITE)
    872 				cpu_dcache_wbinv_range(va, PAGE_SIZE);
    873 			else
    874 				cpu_dcache_inv_range(va, PAGE_SIZE);
    875 		} else if (flags & PVF_WRITE) {
    876 			cpu_dcache_wb_range(va, PAGE_SIZE);
    877 		}
    878 	}
    879 }
    880 
    881 static inline void
    882 pmap_cache_wbinv_all(pmap_t pm, u_int flags)
    883 {
    884 	if (PV_BEEN_EXECD(flags)) {
    885 		if (pm->pm_cstate.cs_cache_id) {
    886 			cpu_idcache_wbinv_all();
    887 			pm->pm_cstate.cs_cache = 0;
    888 		}
    889 	} else if (pm->pm_cstate.cs_cache_d) {
    890 		cpu_dcache_wbinv_all();
    891 		pm->pm_cstate.cs_cache_d = 0;
    892 	}
    893 }
    894 #endif /* PMAP_CACHE_VIVT */
    895 
    896 static inline uint8_t
    897 pmap_domain(pmap_t pm)
    898 {
    899 #ifdef ARM_MMU_EXTENDED
    900 	return pm == pmap_kernel() ? PMAP_DOMAIN_KERNEL : PMAP_DOMAIN_USER;
    901 #else
    902 	return pm->pm_domain;
    903 #endif
    904 }
    905 
    906 static inline pd_entry_t *
    907 pmap_l1_kva(pmap_t pm)
    908 {
    909 #ifdef ARM_MMU_EXTENDED
    910 	return pm->pm_l1;
    911 #else
    912 	return pm->pm_l1->l1_kva;
    913 #endif
    914 }
    915 
    916 static inline bool
    917 pmap_is_current(pmap_t pm)
    918 {
    919 	if (pm == pmap_kernel() || curproc->p_vmspace->vm_map.pmap == pm)
    920 		return true;
    921 
    922 	return false;
    923 }
    924 
    925 static inline bool
    926 pmap_is_cached(pmap_t pm)
    927 {
    928 #ifdef ARM_MMU_EXTENDED
    929 	if (pm == pmap_kernel())
    930 		return true;
    931 #ifdef MULTIPROCESSOR
    932 	// Is this pmap active on any CPU?
    933 	if (!kcpuset_iszero(pm->pm_active))
    934 		return true;
    935 #else
    936 	struct pmap_tlb_info * const ti = cpu_tlb_info(curcpu());
    937 	// Is this pmap active?
    938 	if (PMAP_PAI_ASIDVALID_P(PMAP_PAI(pm, ti), ti))
    939 		return true;
    940 #endif
    941 #else
    942 	struct cpu_info * const ci = curcpu();
    943 	if (pm == pmap_kernel() || ci->ci_pmap_lastuser == NULL
    944 	    || ci->ci_pmap_lastuser == pm)
    945 		return true;
    946 #endif /* ARM_MMU_EXTENDED */
    947 
    948 	return false;
    949 }
    950 
    951 /*
    952  * PTE_SYNC_CURRENT:
    953  *
    954  *     Make sure the pte is written out to RAM.
    955  *     We need to do this for one of two cases:
    956  *       - We're dealing with the kernel pmap
    957  *       - There is no pmap active in the cache/tlb.
    958  *       - The specified pmap is 'active' in the cache/tlb.
    959  */
    960 
    961 static inline void
    962 pmap_pte_sync_current(pmap_t pm, pt_entry_t *ptep)
    963 {
    964 	if (PMAP_NEEDS_PTE_SYNC && pmap_is_cached(pm))
    965 		PTE_SYNC(ptep);
    966 	arm_dsb();
    967 }
    968 
    969 #ifdef PMAP_INCLUDE_PTE_SYNC
    970 #define	PTE_SYNC_CURRENT(pm, ptep)	pmap_pte_sync_current(pm, ptep)
    971 #else
    972 #define	PTE_SYNC_CURRENT(pm, ptep)	/* nothing */
    973 #endif
    974 
    975 /*
    976  * main pv_entry manipulation functions:
    977  *   pmap_enter_pv: enter a mapping onto a vm_page list
    978  *   pmap_remove_pv: remove a mapping from a vm_page list
    979  *
    980  * NOTE: pmap_enter_pv expects to lock the pvh itself
    981  *       pmap_remove_pv expects the caller to lock the pvh before calling
    982  */
    983 
    984 /*
    985  * pmap_enter_pv: enter a mapping onto a vm_page lst
    986  *
    987  * => caller should hold the proper lock on pmap_main_lock
    988  * => caller should have pmap locked
    989  * => we will gain the lock on the vm_page and allocate the new pv_entry
    990  * => caller should adjust ptp's wire_count before calling
    991  * => caller should not adjust pmap's wire_count
    992  */
    993 static void
    994 pmap_enter_pv(struct vm_page_md *md, paddr_t pa, struct pv_entry *pv, pmap_t pm,
    995     vaddr_t va, u_int flags)
    996 {
    997 	struct pv_entry **pvp;
    998 
    999 	NPDEBUG(PDB_PVDUMP,
   1000 	    printf("pmap_enter_pv: pm %p, md %p, flags 0x%x\n", pm, md, flags));
   1001 
   1002 	pv->pv_pmap = pm;
   1003 	pv->pv_va = va;
   1004 	pv->pv_flags = flags;
   1005 
   1006 	pvp = &SLIST_FIRST(&md->pvh_list);
   1007 #ifdef PMAP_CACHE_VIPT
   1008 	/*
   1009 	 * Insert unmanaged entries, writeable first, at the head of
   1010 	 * the pv list.
   1011 	 */
   1012 	if (__predict_true(!PV_IS_KENTRY_P(flags))) {
   1013 		while (*pvp != NULL && PV_IS_KENTRY_P((*pvp)->pv_flags))
   1014 			pvp = &SLIST_NEXT(*pvp, pv_link);
   1015 	}
   1016 	if (!PV_IS_WRITE_P(flags)) {
   1017 		while (*pvp != NULL && PV_IS_WRITE_P((*pvp)->pv_flags))
   1018 			pvp = &SLIST_NEXT(*pvp, pv_link);
   1019 	}
   1020 #endif
   1021 	SLIST_NEXT(pv, pv_link) = *pvp;		/* add to ... */
   1022 	*pvp = pv;				/* ... locked list */
   1023 	md->pvh_attrs |= flags & (PVF_REF | PVF_MOD);
   1024 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   1025 	if ((pv->pv_flags & PVF_KWRITE) == PVF_KWRITE)
   1026 		md->pvh_attrs |= PVF_KMOD;
   1027 	if ((md->pvh_attrs & (PVF_DMOD|PVF_NC)) != PVF_NC)
   1028 		md->pvh_attrs |= PVF_DIRTY;
   1029 	KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   1030 #endif
   1031 	if (pm == pmap_kernel()) {
   1032 		PMAPCOUNT(kernel_mappings);
   1033 		if (flags & PVF_WRITE)
   1034 			md->krw_mappings++;
   1035 		else
   1036 			md->kro_mappings++;
   1037 	} else {
   1038 		if (flags & PVF_WRITE)
   1039 			md->urw_mappings++;
   1040 		else
   1041 			md->uro_mappings++;
   1042 	}
   1043 
   1044 #ifdef PMAP_CACHE_VIPT
   1045 #ifndef ARM_MMU_EXTENDED
   1046 	/*
   1047 	 * Even though pmap_vac_me_harder will set PVF_WRITE for us,
   1048 	 * do it here as well to keep the mappings & KVF_WRITE consistent.
   1049 	 */
   1050 	if (arm_cache_prefer_mask != 0 && (flags & PVF_WRITE) != 0) {
   1051 		md->pvh_attrs |= PVF_WRITE;
   1052 	}
   1053 #endif
   1054 	/*
   1055 	 * If this is an exec mapping and its the first exec mapping
   1056 	 * for this page, make sure to sync the I-cache.
   1057 	 */
   1058 	if (PV_IS_EXEC_P(flags)) {
   1059 #ifndef ARM_MMU_EXTENDED
   1060 		if (!PV_IS_EXEC_P(md->pvh_attrs)) {
   1061 			pmap_syncicache_page(md, pa);
   1062 			PMAPCOUNT(exec_synced_map);
   1063 		}
   1064 #endif
   1065 		PMAPCOUNT(exec_mappings);
   1066 	}
   1067 #endif
   1068 
   1069 	PMAPCOUNT(mappings);
   1070 
   1071 	if (pv->pv_flags & PVF_WIRED)
   1072 		++pm->pm_stats.wired_count;
   1073 }
   1074 
   1075 /*
   1076  *
   1077  * pmap_find_pv: Find a pv entry
   1078  *
   1079  * => caller should hold lock on vm_page
   1080  */
   1081 static inline struct pv_entry *
   1082 pmap_find_pv(struct vm_page_md *md, pmap_t pm, vaddr_t va)
   1083 {
   1084 	struct pv_entry *pv;
   1085 
   1086 	SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
   1087 		if (pm == pv->pv_pmap && va == pv->pv_va)
   1088 			break;
   1089 	}
   1090 
   1091 	return (pv);
   1092 }
   1093 
   1094 /*
   1095  * pmap_remove_pv: try to remove a mapping from a pv_list
   1096  *
   1097  * => caller should hold proper lock on pmap_main_lock
   1098  * => pmap should be locked
   1099  * => caller should hold lock on vm_page [so that attrs can be adjusted]
   1100  * => caller should adjust ptp's wire_count and free PTP if needed
   1101  * => caller should NOT adjust pmap's wire_count
   1102  * => we return the removed pv
   1103  */
   1104 static struct pv_entry *
   1105 pmap_remove_pv(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
   1106 {
   1107 	struct pv_entry *pv, **prevptr;
   1108 
   1109 	NPDEBUG(PDB_PVDUMP,
   1110 	    printf("pmap_remove_pv: pm %p, md %p, va 0x%08lx\n", pm, md, va));
   1111 
   1112 	prevptr = &SLIST_FIRST(&md->pvh_list); /* prev pv_entry ptr */
   1113 	pv = *prevptr;
   1114 
   1115 	while (pv) {
   1116 		if (pv->pv_pmap == pm && pv->pv_va == va) {	/* match? */
   1117 			NPDEBUG(PDB_PVDUMP, printf("pmap_remove_pv: pm %p, md "
   1118 			    "%p, flags 0x%x\n", pm, md, pv->pv_flags));
   1119 			if (pv->pv_flags & PVF_WIRED) {
   1120 				--pm->pm_stats.wired_count;
   1121 			}
   1122 			*prevptr = SLIST_NEXT(pv, pv_link);	/* remove it! */
   1123 			if (pm == pmap_kernel()) {
   1124 				PMAPCOUNT(kernel_unmappings);
   1125 				if (pv->pv_flags & PVF_WRITE)
   1126 					md->krw_mappings--;
   1127 				else
   1128 					md->kro_mappings--;
   1129 			} else {
   1130 				if (pv->pv_flags & PVF_WRITE)
   1131 					md->urw_mappings--;
   1132 				else
   1133 					md->uro_mappings--;
   1134 			}
   1135 
   1136 			PMAPCOUNT(unmappings);
   1137 #ifdef PMAP_CACHE_VIPT
   1138 			if (!(pv->pv_flags & PVF_WRITE))
   1139 				break;
   1140 			/*
   1141 			 * If this page has had an exec mapping, then if
   1142 			 * this was the last mapping, discard the contents,
   1143 			 * otherwise sync the i-cache for this page.
   1144 			 */
   1145 			if (PV_IS_EXEC_P(md->pvh_attrs)) {
   1146 #ifdef ARM_MMU_EXTENDED
   1147 				md->pvh_attrs &= ~PVF_EXEC;
   1148 				PMAPCOUNT(exec_discarded_unmap);
   1149 #else
   1150 				if (SLIST_EMPTY(&md->pvh_list)) {
   1151 					md->pvh_attrs &= ~PVF_EXEC;
   1152 					PMAPCOUNT(exec_discarded_unmap);
   1153 				} else {
   1154 					pmap_syncicache_page(md, pa);
   1155 					PMAPCOUNT(exec_synced_unmap);
   1156 				}
   1157 #endif /* ARM_MMU_EXTENDED */
   1158 			}
   1159 #endif /* PMAP_CACHE_VIPT */
   1160 			break;
   1161 		}
   1162 		prevptr = &SLIST_NEXT(pv, pv_link);	/* previous pointer */
   1163 		pv = *prevptr;				/* advance */
   1164 	}
   1165 
   1166 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   1167 	/*
   1168 	 * If we no longer have a WRITEABLE KENTRY at the head of list,
   1169 	 * clear the KMOD attribute from the page.
   1170 	 */
   1171 	if (SLIST_FIRST(&md->pvh_list) == NULL
   1172 	    || (SLIST_FIRST(&md->pvh_list)->pv_flags & PVF_KWRITE) != PVF_KWRITE)
   1173 		md->pvh_attrs &= ~PVF_KMOD;
   1174 
   1175 	/*
   1176 	 * If this was a writeable page and there are no more writeable
   1177 	 * mappings (ignoring KMPAGE), clear the WRITE flag and writeback
   1178 	 * the contents to memory.
   1179 	 */
   1180 	if (arm_cache_prefer_mask != 0) {
   1181 		if (md->krw_mappings + md->urw_mappings == 0)
   1182 			md->pvh_attrs &= ~PVF_WRITE;
   1183 		PMAP_VALIDATE_MD_PAGE(md);
   1184 	}
   1185 	KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   1186 #endif /* PMAP_CACHE_VIPT && !ARM_MMU_EXTENDED */
   1187 
   1188 	return(pv);				/* return removed pv */
   1189 }
   1190 
   1191 /*
   1192  *
   1193  * pmap_modify_pv: Update pv flags
   1194  *
   1195  * => caller should hold lock on vm_page [so that attrs can be adjusted]
   1196  * => caller should NOT adjust pmap's wire_count
   1197  * => caller must call pmap_vac_me_harder() if writable status of a page
   1198  *    may have changed.
   1199  * => we return the old flags
   1200  *
   1201  * Modify a physical-virtual mapping in the pv table
   1202  */
   1203 static u_int
   1204 pmap_modify_pv(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va,
   1205     u_int clr_mask, u_int set_mask)
   1206 {
   1207 	struct pv_entry *npv;
   1208 	u_int flags, oflags;
   1209 
   1210 	KASSERT(!PV_IS_KENTRY_P(clr_mask));
   1211 	KASSERT(!PV_IS_KENTRY_P(set_mask));
   1212 
   1213 	if ((npv = pmap_find_pv(md, pm, va)) == NULL)
   1214 		return (0);
   1215 
   1216 	NPDEBUG(PDB_PVDUMP,
   1217 	    printf("pmap_modify_pv: pm %p, md %p, clr 0x%x, set 0x%x, flags 0x%x\n", pm, md, clr_mask, set_mask, npv->pv_flags));
   1218 
   1219 	/*
   1220 	 * There is at least one VA mapping this page.
   1221 	 */
   1222 
   1223 	if (clr_mask & (PVF_REF | PVF_MOD)) {
   1224 		md->pvh_attrs |= set_mask & (PVF_REF | PVF_MOD);
   1225 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   1226 		if ((md->pvh_attrs & (PVF_DMOD|PVF_NC)) != PVF_NC)
   1227 			md->pvh_attrs |= PVF_DIRTY;
   1228 		KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   1229 #endif /* PMAP_CACHE_VIPT && !ARM_MMU_EXTENDED */
   1230 	}
   1231 
   1232 	oflags = npv->pv_flags;
   1233 	npv->pv_flags = flags = (oflags & ~clr_mask) | set_mask;
   1234 
   1235 	if ((flags ^ oflags) & PVF_WIRED) {
   1236 		if (flags & PVF_WIRED)
   1237 			++pm->pm_stats.wired_count;
   1238 		else
   1239 			--pm->pm_stats.wired_count;
   1240 	}
   1241 
   1242 	if ((flags ^ oflags) & PVF_WRITE) {
   1243 		if (pm == pmap_kernel()) {
   1244 			if (flags & PVF_WRITE) {
   1245 				md->krw_mappings++;
   1246 				md->kro_mappings--;
   1247 			} else {
   1248 				md->kro_mappings++;
   1249 				md->krw_mappings--;
   1250 			}
   1251 		} else {
   1252 			if (flags & PVF_WRITE) {
   1253 				md->urw_mappings++;
   1254 				md->uro_mappings--;
   1255 			} else {
   1256 				md->uro_mappings++;
   1257 				md->urw_mappings--;
   1258 			}
   1259 		}
   1260 	}
   1261 #ifdef PMAP_CACHE_VIPT
   1262 	if (arm_cache_prefer_mask != 0) {
   1263 		if (md->urw_mappings + md->krw_mappings == 0) {
   1264 			md->pvh_attrs &= ~PVF_WRITE;
   1265 		} else {
   1266 			md->pvh_attrs |= PVF_WRITE;
   1267 		}
   1268 	}
   1269 #ifndef ARM_MMU_EXTENDED
   1270 	/*
   1271 	 * We have two cases here: the first is from enter_pv (new exec
   1272 	 * page), the second is a combined pmap_remove_pv/pmap_enter_pv.
   1273 	 * Since in latter, pmap_enter_pv won't do anything, we just have
   1274 	 * to do what pmap_remove_pv would do.
   1275 	 */
   1276 	if ((PV_IS_EXEC_P(flags) && !PV_IS_EXEC_P(md->pvh_attrs))
   1277 	    || (PV_IS_EXEC_P(md->pvh_attrs)
   1278 		|| (!(flags & PVF_WRITE) && (oflags & PVF_WRITE)))) {
   1279 		pmap_syncicache_page(md, pa);
   1280 		PMAPCOUNT(exec_synced_remap);
   1281 	}
   1282 	KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   1283 #endif /* !ARM_MMU_EXTENDED */
   1284 #endif /* PMAP_CACHE_VIPT */
   1285 
   1286 	PMAPCOUNT(remappings);
   1287 
   1288 	return (oflags);
   1289 }
   1290 
   1291 /*
   1292  * Allocate an L1 translation table for the specified pmap.
   1293  * This is called at pmap creation time.
   1294  */
   1295 static void
   1296 pmap_alloc_l1(pmap_t pm)
   1297 {
   1298 #ifdef ARM_MMU_EXTENDED
   1299 #ifdef __HAVE_MM_MD_DIRECT_MAPPED_PHYS
   1300 	struct vm_page *pg;
   1301 	bool ok __diagused;
   1302 	for (;;) {
   1303 #ifdef PMAP_NEED_ALLOC_POOLPAGE
   1304 		pg = arm_pmap_alloc_poolpage(UVM_PGA_ZERO);
   1305 #else
   1306 		pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_ZERO);
   1307 #endif
   1308 		if (pg != NULL)
   1309 			break;
   1310 		uvm_wait("pmapl1alloc");
   1311 	}
   1312 	pm->pm_l1_pa = VM_PAGE_TO_PHYS(pg);
   1313 	vaddr_t va = pmap_direct_mapped_phys(pm->pm_l1_pa, &ok, 0);
   1314 	KASSERT(ok);
   1315 	KASSERT(va >= KERNEL_BASE);
   1316 
   1317 #else
   1318 	KASSERTMSG(kernel_map != NULL, "pm %p", pm);
   1319 	vaddr_t va = uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
   1320 	    UVM_KMF_WIRED|UVM_KMF_ZERO);
   1321 	KASSERT(va);
   1322 	pmap_extract(pmap_kernel(), va, &pm->pm_l1_pa);
   1323 #endif
   1324 	pm->pm_l1 = (pd_entry_t *)va;
   1325 	PTE_SYNC_RANGE(pm->pm_l1, PAGE_SIZE / sizeof(pt_entry_t));
   1326 #else
   1327 	struct l1_ttable *l1;
   1328 	uint8_t domain;
   1329 
   1330 	/*
   1331 	 * Remove the L1 at the head of the LRU list
   1332 	 */
   1333 	mutex_spin_enter(&l1_lru_lock);
   1334 	l1 = TAILQ_FIRST(&l1_lru_list);
   1335 	KDASSERT(l1 != NULL);
   1336 	TAILQ_REMOVE(&l1_lru_list, l1, l1_lru);
   1337 
   1338 	/*
   1339 	 * Pick the first available domain number, and update
   1340 	 * the link to the next number.
   1341 	 */
   1342 	domain = l1->l1_domain_first;
   1343 	l1->l1_domain_first = l1->l1_domain_free[domain];
   1344 
   1345 	/*
   1346 	 * If there are still free domain numbers in this L1,
   1347 	 * put it back on the TAIL of the LRU list.
   1348 	 */
   1349 	if (++l1->l1_domain_use_count < PMAP_DOMAINS)
   1350 		TAILQ_INSERT_TAIL(&l1_lru_list, l1, l1_lru);
   1351 
   1352 	mutex_spin_exit(&l1_lru_lock);
   1353 
   1354 	/*
   1355 	 * Fix up the relevant bits in the pmap structure
   1356 	 */
   1357 	pm->pm_l1 = l1;
   1358 	pm->pm_domain = domain + 1;
   1359 #endif
   1360 }
   1361 
   1362 /*
   1363  * Free an L1 translation table.
   1364  * This is called at pmap destruction time.
   1365  */
   1366 static void
   1367 pmap_free_l1(pmap_t pm)
   1368 {
   1369 #ifdef ARM_MMU_EXTENDED
   1370 #ifdef __HAVE_MM_MD_DIRECT_MAPPED_PHYS
   1371 	struct vm_page *pg = PHYS_TO_VM_PAGE(pm->pm_l1_pa);
   1372 	uvm_pagefree(pg);
   1373 #else
   1374 	uvm_km_free(kernel_map, (vaddr_t)pm->pm_l1, PAGE_SIZE, UVM_KMF_WIRED);
   1375 #endif
   1376 	pm->pm_l1 = NULL;
   1377 	pm->pm_l1_pa = 0;
   1378 #else
   1379 	struct l1_ttable *l1 = pm->pm_l1;
   1380 
   1381 	mutex_spin_enter(&l1_lru_lock);
   1382 
   1383 	/*
   1384 	 * If this L1 is currently on the LRU list, remove it.
   1385 	 */
   1386 	if (l1->l1_domain_use_count < PMAP_DOMAINS)
   1387 		TAILQ_REMOVE(&l1_lru_list, l1, l1_lru);
   1388 
   1389 	/*
   1390 	 * Free up the domain number which was allocated to the pmap
   1391 	 */
   1392 	l1->l1_domain_free[pmap_domain(pm) - 1] = l1->l1_domain_first;
   1393 	l1->l1_domain_first = pmap_domain(pm) - 1;
   1394 	l1->l1_domain_use_count--;
   1395 
   1396 	/*
   1397 	 * The L1 now must have at least 1 free domain, so add
   1398 	 * it back to the LRU list. If the use count is zero,
   1399 	 * put it at the head of the list, otherwise it goes
   1400 	 * to the tail.
   1401 	 */
   1402 	if (l1->l1_domain_use_count == 0)
   1403 		TAILQ_INSERT_HEAD(&l1_lru_list, l1, l1_lru);
   1404 	else
   1405 		TAILQ_INSERT_TAIL(&l1_lru_list, l1, l1_lru);
   1406 
   1407 	mutex_spin_exit(&l1_lru_lock);
   1408 #endif /* ARM_MMU_EXTENDED */
   1409 }
   1410 
   1411 #ifndef ARM_MMU_EXTENDED
   1412 static inline void
   1413 pmap_use_l1(pmap_t pm)
   1414 {
   1415 	struct l1_ttable *l1;
   1416 
   1417 	/*
   1418 	 * Do nothing if we're in interrupt context.
   1419 	 * Access to an L1 by the kernel pmap must not affect
   1420 	 * the LRU list.
   1421 	 */
   1422 	if (cpu_intr_p() || pm == pmap_kernel())
   1423 		return;
   1424 
   1425 	l1 = pm->pm_l1;
   1426 
   1427 	/*
   1428 	 * If the L1 is not currently on the LRU list, just return
   1429 	 */
   1430 	if (l1->l1_domain_use_count == PMAP_DOMAINS)
   1431 		return;
   1432 
   1433 	mutex_spin_enter(&l1_lru_lock);
   1434 
   1435 	/*
   1436 	 * Check the use count again, now that we've acquired the lock
   1437 	 */
   1438 	if (l1->l1_domain_use_count == PMAP_DOMAINS) {
   1439 		mutex_spin_exit(&l1_lru_lock);
   1440 		return;
   1441 	}
   1442 
   1443 	/*
   1444 	 * Move the L1 to the back of the LRU list
   1445 	 */
   1446 	TAILQ_REMOVE(&l1_lru_list, l1, l1_lru);
   1447 	TAILQ_INSERT_TAIL(&l1_lru_list, l1, l1_lru);
   1448 
   1449 	mutex_spin_exit(&l1_lru_lock);
   1450 }
   1451 #endif /* !ARM_MMU_EXTENDED */
   1452 
   1453 /*
   1454  * void pmap_free_l2_ptp(pt_entry_t *, paddr_t *)
   1455  *
   1456  * Free an L2 descriptor table.
   1457  */
   1458 static inline void
   1459 #if defined(PMAP_INCLUDE_PTE_SYNC) && defined(PMAP_CACHE_VIVT)
   1460 pmap_free_l2_ptp(bool need_sync, pt_entry_t *l2, paddr_t pa)
   1461 #else
   1462 pmap_free_l2_ptp(pt_entry_t *l2, paddr_t pa)
   1463 #endif
   1464 {
   1465 #if defined(PMAP_INCLUDE_PTE_SYNC) && defined(PMAP_CACHE_VIVT)
   1466 	/*
   1467 	 * Note: With a write-back cache, we may need to sync this
   1468 	 * L2 table before re-using it.
   1469 	 * This is because it may have belonged to a non-current
   1470 	 * pmap, in which case the cache syncs would have been
   1471 	 * skipped for the pages that were being unmapped. If the
   1472 	 * L2 table were then to be immediately re-allocated to
   1473 	 * the *current* pmap, it may well contain stale mappings
   1474 	 * which have not yet been cleared by a cache write-back
   1475 	 * and so would still be visible to the mmu.
   1476 	 */
   1477 	if (need_sync)
   1478 		PTE_SYNC_RANGE(l2, L2_TABLE_SIZE_REAL / sizeof(pt_entry_t));
   1479 #endif /* PMAP_INCLUDE_PTE_SYNC && PMAP_CACHE_VIVT */
   1480 	pool_cache_put_paddr(&pmap_l2ptp_cache, (void *)l2, pa);
   1481 }
   1482 
   1483 /*
   1484  * Returns a pointer to the L2 bucket associated with the specified pmap
   1485  * and VA, or NULL if no L2 bucket exists for the address.
   1486  */
   1487 static inline struct l2_bucket *
   1488 pmap_get_l2_bucket(pmap_t pm, vaddr_t va)
   1489 {
   1490 	const size_t l1slot = l1pte_index(va);
   1491 	struct l2_dtable *l2;
   1492 	struct l2_bucket *l2b;
   1493 
   1494 	if ((l2 = pm->pm_l2[L2_IDX(l1slot)]) == NULL ||
   1495 	    (l2b = &l2->l2_bucket[L2_BUCKET(l1slot)])->l2b_kva == NULL)
   1496 		return (NULL);
   1497 
   1498 	return (l2b);
   1499 }
   1500 
   1501 /*
   1502  * Returns a pointer to the L2 bucket associated with the specified pmap
   1503  * and VA.
   1504  *
   1505  * If no L2 bucket exists, perform the necessary allocations to put an L2
   1506  * bucket/page table in place.
   1507  *
   1508  * Note that if a new L2 bucket/page was allocated, the caller *must*
   1509  * increment the bucket occupancy counter appropriately *before*
   1510  * releasing the pmap's lock to ensure no other thread or cpu deallocates
   1511  * the bucket/page in the meantime.
   1512  */
   1513 static struct l2_bucket *
   1514 pmap_alloc_l2_bucket(pmap_t pm, vaddr_t va)
   1515 {
   1516 	const size_t l1slot = l1pte_index(va);
   1517 	struct l2_dtable *l2;
   1518 
   1519 	if ((l2 = pm->pm_l2[L2_IDX(l1slot)]) == NULL) {
   1520 		/*
   1521 		 * No mapping at this address, as there is
   1522 		 * no entry in the L1 table.
   1523 		 * Need to allocate a new l2_dtable.
   1524 		 */
   1525 		if ((l2 = pmap_alloc_l2_dtable()) == NULL)
   1526 			return (NULL);
   1527 
   1528 		/*
   1529 		 * Link it into the parent pmap
   1530 		 */
   1531 		pm->pm_l2[L2_IDX(l1slot)] = l2;
   1532 	}
   1533 
   1534 	struct l2_bucket * const l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];
   1535 
   1536 	/*
   1537 	 * Fetch pointer to the L2 page table associated with the address.
   1538 	 */
   1539 	if (l2b->l2b_kva == NULL) {
   1540 		pt_entry_t *ptep;
   1541 
   1542 		/*
   1543 		 * No L2 page table has been allocated. Chances are, this
   1544 		 * is because we just allocated the l2_dtable, above.
   1545 		 */
   1546 		if ((ptep = pmap_alloc_l2_ptp(&l2b->l2b_pa)) == NULL) {
   1547 			/*
   1548 			 * Oops, no more L2 page tables available at this
   1549 			 * time. We may need to deallocate the l2_dtable
   1550 			 * if we allocated a new one above.
   1551 			 */
   1552 			if (l2->l2_occupancy == 0) {
   1553 				pm->pm_l2[L2_IDX(l1slot)] = NULL;
   1554 				pmap_free_l2_dtable(l2);
   1555 			}
   1556 			return (NULL);
   1557 		}
   1558 
   1559 		l2->l2_occupancy++;
   1560 		l2b->l2b_kva = ptep;
   1561 		l2b->l2b_l1slot = l1slot;
   1562 
   1563 #ifdef ARM_MMU_EXTENDED
   1564 		/*
   1565 		 * We know there will be a mapping here, so simply
   1566 		 * enter this PTP into the L1 now.
   1567 		 */
   1568 		pd_entry_t * const pdep = pmap_l1_kva(pm) + l1slot;
   1569 		pd_entry_t npde = L1_C_PROTO | l2b->l2b_pa
   1570 		    | L1_C_DOM(pmap_domain(pm));
   1571 		KASSERT(*pdep == 0);
   1572 		l1pte_setone(pdep, npde);
   1573 		PDE_SYNC(pdep);
   1574 #endif
   1575 	}
   1576 
   1577 	return (l2b);
   1578 }
   1579 
   1580 /*
   1581  * One or more mappings in the specified L2 descriptor table have just been
   1582  * invalidated.
   1583  *
   1584  * Garbage collect the metadata and descriptor table itself if necessary.
   1585  *
   1586  * The pmap lock must be acquired when this is called (not necessary
   1587  * for the kernel pmap).
   1588  */
   1589 static void
   1590 pmap_free_l2_bucket(pmap_t pm, struct l2_bucket *l2b, u_int count)
   1591 {
   1592 	KDASSERT(count <= l2b->l2b_occupancy);
   1593 
   1594 	/*
   1595 	 * Update the bucket's reference count according to how many
   1596 	 * PTEs the caller has just invalidated.
   1597 	 */
   1598 	l2b->l2b_occupancy -= count;
   1599 
   1600 	/*
   1601 	 * Note:
   1602 	 *
   1603 	 * Level 2 page tables allocated to the kernel pmap are never freed
   1604 	 * as that would require checking all Level 1 page tables and
   1605 	 * removing any references to the Level 2 page table. See also the
   1606 	 * comment elsewhere about never freeing bootstrap L2 descriptors.
   1607 	 *
   1608 	 * We make do with just invalidating the mapping in the L2 table.
   1609 	 *
   1610 	 * This isn't really a big deal in practice and, in fact, leads
   1611 	 * to a performance win over time as we don't need to continually
   1612 	 * alloc/free.
   1613 	 */
   1614 	if (l2b->l2b_occupancy > 0 || pm == pmap_kernel())
   1615 		return;
   1616 
   1617 	/*
   1618 	 * There are no more valid mappings in this level 2 page table.
   1619 	 * Go ahead and NULL-out the pointer in the bucket, then
   1620 	 * free the page table.
   1621 	 */
   1622 	const size_t l1slot = l2b->l2b_l1slot;
   1623 	pt_entry_t * const ptep = l2b->l2b_kva;
   1624 	l2b->l2b_kva = NULL;
   1625 
   1626 	pd_entry_t * const pdep = pmap_l1_kva(pm) + l1slot;
   1627 	pd_entry_t pde __diagused = *pdep;
   1628 
   1629 #ifdef ARM_MMU_EXTENDED
   1630 	/*
   1631 	 * Invalidate the L1 slot.
   1632 	 */
   1633 	KASSERT((pde & L1_TYPE_MASK) == L1_TYPE_C);
   1634 #else
   1635 	/*
   1636 	 * If the L1 slot matches the pmap's domain number, then invalidate it.
   1637 	 */
   1638 	if ((pde & (L1_C_DOM_MASK|L1_TYPE_MASK))
   1639 	    == (L1_C_DOM(pmap_domain(pm))|L1_TYPE_C)) {
   1640 #endif
   1641 		l1pte_setone(pdep, 0);
   1642 		PDE_SYNC(pdep);
   1643 #ifndef ARM_MMU_EXTENDED
   1644 	}
   1645 #endif
   1646 
   1647 	/*
   1648 	 * Release the L2 descriptor table back to the pool cache.
   1649 	 */
   1650 #if defined(PMAP_INCLUDE_PTE_SYNC) && defined(PMAP_CACHE_VIVT)
   1651 	pmap_free_l2_ptp(!pmap_is_cached(pm), ptep, l2b->l2b_pa);
   1652 #else
   1653 	pmap_free_l2_ptp(ptep, l2b->l2b_pa);
   1654 #endif
   1655 
   1656 	/*
   1657 	 * Update the reference count in the associated l2_dtable
   1658 	 */
   1659 	struct l2_dtable * const l2 = pm->pm_l2[L2_IDX(l1slot)];
   1660 	if (--l2->l2_occupancy > 0)
   1661 		return;
   1662 
   1663 	/*
   1664 	 * There are no more valid mappings in any of the Level 1
   1665 	 * slots managed by this l2_dtable. Go ahead and NULL-out
   1666 	 * the pointer in the parent pmap and free the l2_dtable.
   1667 	 */
   1668 	pm->pm_l2[L2_IDX(l1slot)] = NULL;
   1669 	pmap_free_l2_dtable(l2);
   1670 }
   1671 
   1672 /*
   1673  * Pool cache constructors for L2 descriptor tables, metadata and pmap
   1674  * structures.
   1675  */
   1676 static int
   1677 pmap_l2ptp_ctor(void *arg, void *v, int flags)
   1678 {
   1679 #ifndef PMAP_INCLUDE_PTE_SYNC
   1680 	vaddr_t va = (vaddr_t)v & ~PGOFSET;
   1681 
   1682 	/*
   1683 	 * The mappings for these page tables were initially made using
   1684 	 * pmap_kenter_pa() by the pool subsystem. Therefore, the cache-
   1685 	 * mode will not be right for page table mappings. To avoid
   1686 	 * polluting the pmap_kenter_pa() code with a special case for
   1687 	 * page tables, we simply fix up the cache-mode here if it's not
   1688 	 * correct.
   1689 	 */
   1690 	if (pte_l2_s_cache_mode != pte_l2_s_cache_mode_pt) {
   1691 		const struct l2_bucket * const l2b =
   1692 		    pmap_get_l2_bucket(pmap_kernel(), va);
   1693 		KASSERTMSG(l2b != NULL, "%#lx", va);
   1694 		pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
   1695 		const pt_entry_t opte = *ptep;
   1696 
   1697 		if ((opte & L2_S_CACHE_MASK) != pte_l2_s_cache_mode_pt) {
   1698 			/*
   1699 			 * Page tables must have the cache-mode set correctly.
   1700 			 */
   1701 			const pt_entry_t npte = (pte & ~L2_S_CACHE_MASK)
   1702 			    | pte_l2_s_cache_mode_pt;
   1703 			l2pte_set(ptep, npte, opte);
   1704 			PTE_SYNC(ptep);
   1705 			cpu_tlb_flushD_SE(va);
   1706 			cpu_cpwait();
   1707 		}
   1708 	}
   1709 #endif
   1710 
   1711 	memset(v, 0, L2_TABLE_SIZE_REAL);
   1712 	PTE_SYNC_RANGE(v, L2_TABLE_SIZE_REAL / sizeof(pt_entry_t));
   1713 	return (0);
   1714 }
   1715 
   1716 static int
   1717 pmap_l2dtable_ctor(void *arg, void *v, int flags)
   1718 {
   1719 
   1720 	memset(v, 0, sizeof(struct l2_dtable));
   1721 	return (0);
   1722 }
   1723 
   1724 static int
   1725 pmap_pmap_ctor(void *arg, void *v, int flags)
   1726 {
   1727 
   1728 	memset(v, 0, sizeof(struct pmap));
   1729 	return (0);
   1730 }
   1731 
   1732 static void
   1733 pmap_pinit(pmap_t pm)
   1734 {
   1735 #ifndef ARM_HAS_VBAR
   1736 	struct l2_bucket *l2b;
   1737 
   1738 	if (vector_page < KERNEL_BASE) {
   1739 		/*
   1740 		 * Map the vector page.
   1741 		 */
   1742 		pmap_enter(pm, vector_page, systempage.pv_pa,
   1743 		    VM_PROT_READ | VM_PROT_EXECUTE,
   1744 		    VM_PROT_READ | VM_PROT_EXECUTE | PMAP_WIRED);
   1745 		pmap_update(pm);
   1746 
   1747 		pm->pm_pl1vec = pmap_l1_kva(pm) + l1pte_index(vector_page);
   1748 		l2b = pmap_get_l2_bucket(pm, vector_page);
   1749 		KASSERTMSG(l2b != NULL, "%#lx", vector_page);
   1750 		pm->pm_l1vec = l2b->l2b_pa | L1_C_PROTO |
   1751 		    L1_C_DOM(pmap_domain(pm));
   1752 	} else
   1753 		pm->pm_pl1vec = NULL;
   1754 #endif
   1755 }
   1756 
   1757 #ifdef PMAP_CACHE_VIVT
   1758 /*
   1759  * Since we have a virtually indexed cache, we may need to inhibit caching if
   1760  * there is more than one mapping and at least one of them is writable.
   1761  * Since we purge the cache on every context switch, we only need to check for
   1762  * other mappings within the same pmap, or kernel_pmap.
   1763  * This function is also called when a page is unmapped, to possibly reenable
   1764  * caching on any remaining mappings.
   1765  *
   1766  * The code implements the following logic, where:
   1767  *
   1768  * KW = # of kernel read/write pages
   1769  * KR = # of kernel read only pages
   1770  * UW = # of user read/write pages
   1771  * UR = # of user read only pages
   1772  *
   1773  * KC = kernel mapping is cacheable
   1774  * UC = user mapping is cacheable
   1775  *
   1776  *               KW=0,KR=0  KW=0,KR>0  KW=1,KR=0  KW>1,KR>=0
   1777  *             +---------------------------------------------
   1778  * UW=0,UR=0   | ---        KC=1       KC=1       KC=0
   1779  * UW=0,UR>0   | UC=1       KC=1,UC=1  KC=0,UC=0  KC=0,UC=0
   1780  * UW=1,UR=0   | UC=1       KC=0,UC=0  KC=0,UC=0  KC=0,UC=0
   1781  * UW>1,UR>=0  | UC=0       KC=0,UC=0  KC=0,UC=0  KC=0,UC=0
   1782  */
   1783 
   1784 static const int pmap_vac_flags[4][4] = {
   1785 	{-1,		0,		0,		PVF_KNC},
   1786 	{0,		0,		PVF_NC,		PVF_NC},
   1787 	{0,		PVF_NC,		PVF_NC,		PVF_NC},
   1788 	{PVF_UNC,	PVF_NC,		PVF_NC,		PVF_NC}
   1789 };
   1790 
   1791 static inline int
   1792 pmap_get_vac_flags(const struct vm_page_md *md)
   1793 {
   1794 	int kidx, uidx;
   1795 
   1796 	kidx = 0;
   1797 	if (md->kro_mappings || md->krw_mappings > 1)
   1798 		kidx |= 1;
   1799 	if (md->krw_mappings)
   1800 		kidx |= 2;
   1801 
   1802 	uidx = 0;
   1803 	if (md->uro_mappings || md->urw_mappings > 1)
   1804 		uidx |= 1;
   1805 	if (md->urw_mappings)
   1806 		uidx |= 2;
   1807 
   1808 	return (pmap_vac_flags[uidx][kidx]);
   1809 }
   1810 
   1811 static inline void
   1812 pmap_vac_me_harder(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
   1813 {
   1814 	int nattr;
   1815 
   1816 	nattr = pmap_get_vac_flags(md);
   1817 
   1818 	if (nattr < 0) {
   1819 		md->pvh_attrs &= ~PVF_NC;
   1820 		return;
   1821 	}
   1822 
   1823 	if (nattr == 0 && (md->pvh_attrs & PVF_NC) == 0)
   1824 		return;
   1825 
   1826 	if (pm == pmap_kernel())
   1827 		pmap_vac_me_kpmap(md, pa, pm, va);
   1828 	else
   1829 		pmap_vac_me_user(md, pa, pm, va);
   1830 
   1831 	md->pvh_attrs = (md->pvh_attrs & ~PVF_NC) | nattr;
   1832 }
   1833 
   1834 static void
   1835 pmap_vac_me_kpmap(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
   1836 {
   1837 	u_int u_cacheable, u_entries;
   1838 	struct pv_entry *pv;
   1839 	pmap_t last_pmap = pm;
   1840 
   1841 	/*
   1842 	 * Pass one, see if there are both kernel and user pmaps for
   1843 	 * this page.  Calculate whether there are user-writable or
   1844 	 * kernel-writable pages.
   1845 	 */
   1846 	u_cacheable = 0;
   1847 	SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
   1848 		if (pv->pv_pmap != pm && (pv->pv_flags & PVF_NC) == 0)
   1849 			u_cacheable++;
   1850 	}
   1851 
   1852 	u_entries = md->urw_mappings + md->uro_mappings;
   1853 
   1854 	/*
   1855 	 * We know we have just been updating a kernel entry, so if
   1856 	 * all user pages are already cacheable, then there is nothing
   1857 	 * further to do.
   1858 	 */
   1859 	if (md->k_mappings == 0 && u_cacheable == u_entries)
   1860 		return;
   1861 
   1862 	if (u_entries) {
   1863 		/*
   1864 		 * Scan over the list again, for each entry, if it
   1865 		 * might not be set correctly, call pmap_vac_me_user
   1866 		 * to recalculate the settings.
   1867 		 */
   1868 		SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
   1869 			/*
   1870 			 * We know kernel mappings will get set
   1871 			 * correctly in other calls.  We also know
   1872 			 * that if the pmap is the same as last_pmap
   1873 			 * then we've just handled this entry.
   1874 			 */
   1875 			if (pv->pv_pmap == pm || pv->pv_pmap == last_pmap)
   1876 				continue;
   1877 
   1878 			/*
   1879 			 * If there are kernel entries and this page
   1880 			 * is writable but non-cacheable, then we can
   1881 			 * skip this entry also.
   1882 			 */
   1883 			if (md->k_mappings &&
   1884 			    (pv->pv_flags & (PVF_NC | PVF_WRITE)) ==
   1885 			    (PVF_NC | PVF_WRITE))
   1886 				continue;
   1887 
   1888 			/*
   1889 			 * Similarly if there are no kernel-writable
   1890 			 * entries and the page is already
   1891 			 * read-only/cacheable.
   1892 			 */
   1893 			if (md->krw_mappings == 0 &&
   1894 			    (pv->pv_flags & (PVF_NC | PVF_WRITE)) == 0)
   1895 				continue;
   1896 
   1897 			/*
   1898 			 * For some of the remaining cases, we know
   1899 			 * that we must recalculate, but for others we
   1900 			 * can't tell if they are correct or not, so
   1901 			 * we recalculate anyway.
   1902 			 */
   1903 			pmap_vac_me_user(md, pa, (last_pmap = pv->pv_pmap), 0);
   1904 		}
   1905 
   1906 		if (md->k_mappings == 0)
   1907 			return;
   1908 	}
   1909 
   1910 	pmap_vac_me_user(md, pa, pm, va);
   1911 }
   1912 
   1913 static void
   1914 pmap_vac_me_user(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
   1915 {
   1916 	pmap_t kpmap = pmap_kernel();
   1917 	struct pv_entry *pv, *npv = NULL;
   1918 	u_int entries = 0;
   1919 	u_int writable = 0;
   1920 	u_int cacheable_entries = 0;
   1921 	u_int kern_cacheable = 0;
   1922 	u_int other_writable = 0;
   1923 
   1924 	/*
   1925 	 * Count mappings and writable mappings in this pmap.
   1926 	 * Include kernel mappings as part of our own.
   1927 	 * Keep a pointer to the first one.
   1928 	 */
   1929 	npv = NULL;
   1930 	KASSERT(pmap_page_locked_p(md));
   1931 	SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
   1932 		/* Count mappings in the same pmap */
   1933 		if (pm == pv->pv_pmap || kpmap == pv->pv_pmap) {
   1934 			if (entries++ == 0)
   1935 				npv = pv;
   1936 
   1937 			/* Cacheable mappings */
   1938 			if ((pv->pv_flags & PVF_NC) == 0) {
   1939 				cacheable_entries++;
   1940 				if (kpmap == pv->pv_pmap)
   1941 					kern_cacheable++;
   1942 			}
   1943 
   1944 			/* Writable mappings */
   1945 			if (pv->pv_flags & PVF_WRITE)
   1946 				++writable;
   1947 		} else
   1948 		if (pv->pv_flags & PVF_WRITE)
   1949 			other_writable = 1;
   1950 	}
   1951 
   1952 	/*
   1953 	 * Enable or disable caching as necessary.
   1954 	 * Note: the first entry might be part of the kernel pmap,
   1955 	 * so we can't assume this is indicative of the state of the
   1956 	 * other (maybe non-kpmap) entries.
   1957 	 */
   1958 	if ((entries > 1 && writable) ||
   1959 	    (entries > 0 && pm == kpmap && other_writable)) {
   1960 		if (cacheable_entries == 0) {
   1961 			return;
   1962 		}
   1963 
   1964 		for (pv = npv; pv; pv = SLIST_NEXT(pv, pv_link)) {
   1965 			if ((pm != pv->pv_pmap && kpmap != pv->pv_pmap) ||
   1966 			    (pv->pv_flags & PVF_NC))
   1967 				continue;
   1968 
   1969 			pv->pv_flags |= PVF_NC;
   1970 
   1971 			struct l2_bucket * const l2b
   1972 			    = pmap_get_l2_bucket(pv->pv_pmap, pv->pv_va);
   1973 			KASSERTMSG(l2b != NULL, "%#lx", va);
   1974 			pt_entry_t * const ptep
   1975 			    = &l2b->l2b_kva[l2pte_index(pv->pv_va)];
   1976 			const pt_entry_t opte = *ptep;
   1977 			pt_entry_t npte = opte & ~L2_S_CACHE_MASK;
   1978 
   1979 			if ((va != pv->pv_va || pm != pv->pv_pmap)
   1980 			    && l2pte_valid_p(npte)) {
   1981 #ifdef PMAP_CACHE_VIVT
   1982 				pmap_cache_wbinv_page(pv->pv_pmap, pv->pv_va,
   1983 				    true, pv->pv_flags);
   1984 #endif
   1985 				pmap_tlb_flush_SE(pv->pv_pmap, pv->pv_va,
   1986 				    pv->pv_flags);
   1987 			}
   1988 
   1989 			l2pte_set(ptep, npte, opte);
   1990 			PTE_SYNC_CURRENT(pv->pv_pmap, ptep);
   1991 		}
   1992 		cpu_cpwait();
   1993 	} else
   1994 	if (entries > cacheable_entries) {
   1995 		/*
   1996 		 * Turn cacheing back on for some pages.  If it is a kernel
   1997 		 * page, only do so if there are no other writable pages.
   1998 		 */
   1999 		for (pv = npv; pv; pv = SLIST_NEXT(pv, pv_link)) {
   2000 			if (!(pv->pv_flags & PVF_NC) || (pm != pv->pv_pmap &&
   2001 			    (kpmap != pv->pv_pmap || other_writable)))
   2002 				continue;
   2003 
   2004 			pv->pv_flags &= ~PVF_NC;
   2005 
   2006 			struct l2_bucket * const l2b
   2007 			    = pmap_get_l2_bucket(pv->pv_pmap, pv->pv_va);
   2008 			KASSERTMSG(l2b != NULL, "%#lx", va);
   2009 			pt_entry_t * const ptep
   2010 			    = &l2b->l2b_kva[l2pte_index(pv->pv_va)];
   2011 			const pt_entry_t opte = *ptep;
   2012 			pt_entry_t npte = (opte & ~L2_S_CACHE_MASK)
   2013 			    | pte_l2_s_cache_mode;
   2014 
   2015 			if (l2pte_valid_p(opte)) {
   2016 				pmap_tlb_flush_SE(pv->pv_pmap, pv->pv_va,
   2017 				    pv->pv_flags);
   2018 			}
   2019 
   2020 			l2pte_set(ptep, npte, opte);
   2021 			PTE_SYNC_CURRENT(pv->pv_pmap, ptep);
   2022 		}
   2023 	}
   2024 }
   2025 #endif
   2026 
   2027 #ifdef PMAP_CACHE_VIPT
   2028 static void
   2029 pmap_vac_me_harder(struct vm_page_md *md, paddr_t pa, pmap_t pm, vaddr_t va)
   2030 {
   2031 #ifndef ARM_MMU_EXTENDED
   2032 	struct pv_entry *pv;
   2033 	vaddr_t tst_mask;
   2034 	bool bad_alias;
   2035 	const u_int
   2036 	    rw_mappings = md->urw_mappings + md->krw_mappings,
   2037 	    ro_mappings = md->uro_mappings + md->kro_mappings;
   2038 
   2039 	/* do we need to do anything? */
   2040 	if (arm_cache_prefer_mask == 0)
   2041 		return;
   2042 
   2043 	NPDEBUG(PDB_VAC, printf("pmap_vac_me_harder: md=%p, pmap=%p va=%08lx\n",
   2044 	    md, pm, va));
   2045 
   2046 	KASSERT(!va || pm);
   2047 	KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2048 
   2049 	/* Already a conflict? */
   2050 	if (__predict_false(md->pvh_attrs & PVF_NC)) {
   2051 		/* just an add, things are already non-cached */
   2052 		KASSERT(!(md->pvh_attrs & PVF_DIRTY));
   2053 		KASSERT(!(md->pvh_attrs & PVF_MULTCLR));
   2054 		bad_alias = false;
   2055 		if (va) {
   2056 			PMAPCOUNT(vac_color_none);
   2057 			bad_alias = true;
   2058 			KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
   2059 			goto fixup;
   2060 		}
   2061 		pv = SLIST_FIRST(&md->pvh_list);
   2062 		/* the list can't be empty because it would be cachable */
   2063 		if (md->pvh_attrs & PVF_KMPAGE) {
   2064 			tst_mask = md->pvh_attrs;
   2065 		} else {
   2066 			KASSERT(pv);
   2067 			tst_mask = pv->pv_va;
   2068 			pv = SLIST_NEXT(pv, pv_link);
   2069 		}
   2070 		/*
   2071 		 * Only check for a bad alias if we have writable mappings.
   2072 		 */
   2073 		tst_mask &= arm_cache_prefer_mask;
   2074 		if (rw_mappings > 0) {
   2075 			for (; pv && !bad_alias; pv = SLIST_NEXT(pv, pv_link)) {
   2076 				/* if there's a bad alias, stop checking. */
   2077 				if (tst_mask != (pv->pv_va & arm_cache_prefer_mask))
   2078 					bad_alias = true;
   2079 			}
   2080 			md->pvh_attrs |= PVF_WRITE;
   2081 			if (!bad_alias)
   2082 				md->pvh_attrs |= PVF_DIRTY;
   2083 		} else {
   2084 			/*
   2085 			 * We have only read-only mappings.  Let's see if there
   2086 			 * are multiple colors in use or if we mapped a KMPAGE.
   2087 			 * If the latter, we have a bad alias.  If the former,
   2088 			 * we need to remember that.
   2089 			 */
   2090 			for (; pv; pv = SLIST_NEXT(pv, pv_link)) {
   2091 				if (tst_mask != (pv->pv_va & arm_cache_prefer_mask)) {
   2092 					if (md->pvh_attrs & PVF_KMPAGE)
   2093 						bad_alias = true;
   2094 					break;
   2095 				}
   2096 			}
   2097 			md->pvh_attrs &= ~PVF_WRITE;
   2098 			/*
   2099 			 * No KMPAGE and we exited early, so we must have
   2100 			 * multiple color mappings.
   2101 			 */
   2102 			if (!bad_alias && pv != NULL)
   2103 				md->pvh_attrs |= PVF_MULTCLR;
   2104 		}
   2105 
   2106 		/* If no conflicting colors, set everything back to cached */
   2107 		if (!bad_alias) {
   2108 #ifdef DEBUG
   2109 			if ((md->pvh_attrs & PVF_WRITE)
   2110 			    || ro_mappings < 2) {
   2111 				SLIST_FOREACH(pv, &md->pvh_list, pv_link)
   2112 					KDASSERT(((tst_mask ^ pv->pv_va) & arm_cache_prefer_mask) == 0);
   2113 			}
   2114 #endif
   2115 			md->pvh_attrs &= (PAGE_SIZE - 1) & ~PVF_NC;
   2116 			md->pvh_attrs |= tst_mask | PVF_COLORED;
   2117 			/*
   2118 			 * Restore DIRTY bit if page is modified
   2119 			 */
   2120 			if (md->pvh_attrs & PVF_DMOD)
   2121 				md->pvh_attrs |= PVF_DIRTY;
   2122 			PMAPCOUNT(vac_color_restore);
   2123 		} else {
   2124 			KASSERT(SLIST_FIRST(&md->pvh_list) != NULL);
   2125 			KASSERT(SLIST_NEXT(SLIST_FIRST(&md->pvh_list), pv_link) != NULL);
   2126 		}
   2127 		KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2128 		KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
   2129 	} else if (!va) {
   2130 		KASSERT(pmap_is_page_colored_p(md));
   2131 		KASSERT(!(md->pvh_attrs & PVF_WRITE)
   2132 		    || (md->pvh_attrs & PVF_DIRTY));
   2133 		if (rw_mappings == 0) {
   2134 			md->pvh_attrs &= ~PVF_WRITE;
   2135 			if (ro_mappings == 1
   2136 			    && (md->pvh_attrs & PVF_MULTCLR)) {
   2137 				/*
   2138 				 * If this is the last readonly mapping
   2139 				 * but it doesn't match the current color
   2140 				 * for the page, change the current color
   2141 				 * to match this last readonly mapping.
   2142 				 */
   2143 				pv = SLIST_FIRST(&md->pvh_list);
   2144 				tst_mask = (md->pvh_attrs ^ pv->pv_va)
   2145 				    & arm_cache_prefer_mask;
   2146 				if (tst_mask) {
   2147 					md->pvh_attrs ^= tst_mask;
   2148 					PMAPCOUNT(vac_color_change);
   2149 				}
   2150 			}
   2151 		}
   2152 		KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2153 		KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
   2154 		return;
   2155 	} else if (!pmap_is_page_colored_p(md)) {
   2156 		/* not colored so we just use its color */
   2157 		KASSERT(md->pvh_attrs & (PVF_WRITE|PVF_DIRTY));
   2158 		KASSERT(!(md->pvh_attrs & PVF_MULTCLR));
   2159 		PMAPCOUNT(vac_color_new);
   2160 		md->pvh_attrs &= PAGE_SIZE - 1;
   2161 		md->pvh_attrs |= PVF_COLORED
   2162 		    | (va & arm_cache_prefer_mask)
   2163 		    | (rw_mappings > 0 ? PVF_WRITE : 0);
   2164 		KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2165 		KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
   2166 		return;
   2167 	} else if (((md->pvh_attrs ^ va) & arm_cache_prefer_mask) == 0) {
   2168 		bad_alias = false;
   2169 		if (rw_mappings > 0) {
   2170 			/*
   2171 			 * We now have writeable mappings and if we have
   2172 			 * readonly mappings in more than once color, we have
   2173 			 * an aliasing problem.  Regardless mark the page as
   2174 			 * writeable.
   2175 			 */
   2176 			if (md->pvh_attrs & PVF_MULTCLR) {
   2177 				if (ro_mappings < 2) {
   2178 					/*
   2179 					 * If we only have less than two
   2180 					 * read-only mappings, just flush the
   2181 					 * non-primary colors from the cache.
   2182 					 */
   2183 					pmap_flush_page(md, pa,
   2184 					    PMAP_FLUSH_SECONDARY);
   2185 				} else {
   2186 					bad_alias = true;
   2187 				}
   2188 			}
   2189 			md->pvh_attrs |= PVF_WRITE;
   2190 		}
   2191 		/* If no conflicting colors, set everything back to cached */
   2192 		if (!bad_alias) {
   2193 #ifdef DEBUG
   2194 			if (rw_mappings > 0
   2195 			    || (md->pvh_attrs & PMAP_KMPAGE)) {
   2196 				tst_mask = md->pvh_attrs & arm_cache_prefer_mask;
   2197 				SLIST_FOREACH(pv, &md->pvh_list, pv_link)
   2198 					KDASSERT(((tst_mask ^ pv->pv_va) & arm_cache_prefer_mask) == 0);
   2199 			}
   2200 #endif
   2201 			if (SLIST_EMPTY(&md->pvh_list))
   2202 				PMAPCOUNT(vac_color_reuse);
   2203 			else
   2204 				PMAPCOUNT(vac_color_ok);
   2205 
   2206 			/* matching color, just return */
   2207 			KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2208 			KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
   2209 			return;
   2210 		}
   2211 		KASSERT(SLIST_FIRST(&md->pvh_list) != NULL);
   2212 		KASSERT(SLIST_NEXT(SLIST_FIRST(&md->pvh_list), pv_link) != NULL);
   2213 
   2214 		/* color conflict.  evict from cache. */
   2215 
   2216 		pmap_flush_page(md, pa, PMAP_FLUSH_PRIMARY);
   2217 		md->pvh_attrs &= ~PVF_COLORED;
   2218 		md->pvh_attrs |= PVF_NC;
   2219 		KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2220 		KASSERT(!(md->pvh_attrs & PVF_MULTCLR));
   2221 		PMAPCOUNT(vac_color_erase);
   2222 	} else if (rw_mappings == 0
   2223 		   && (md->pvh_attrs & PVF_KMPAGE) == 0) {
   2224 		KASSERT((md->pvh_attrs & PVF_WRITE) == 0);
   2225 
   2226 		/*
   2227 		 * If the page has dirty cache lines, clean it.
   2228 		 */
   2229 		if (md->pvh_attrs & PVF_DIRTY)
   2230 			pmap_flush_page(md, pa, PMAP_CLEAN_PRIMARY);
   2231 
   2232 		/*
   2233 		 * If this is the first remapping (we know that there are no
   2234 		 * writeable mappings), then this is a simple color change.
   2235 		 * Otherwise this is a seconary r/o mapping, which means
   2236 		 * we don't have to do anything.
   2237 		 */
   2238 		if (ro_mappings == 1) {
   2239 			KASSERT(((md->pvh_attrs ^ va) & arm_cache_prefer_mask) != 0);
   2240 			md->pvh_attrs &= PAGE_SIZE - 1;
   2241 			md->pvh_attrs |= (va & arm_cache_prefer_mask);
   2242 			PMAPCOUNT(vac_color_change);
   2243 		} else {
   2244 			PMAPCOUNT(vac_color_blind);
   2245 		}
   2246 		md->pvh_attrs |= PVF_MULTCLR;
   2247 		KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2248 		KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
   2249 		return;
   2250 	} else {
   2251 		if (rw_mappings > 0)
   2252 			md->pvh_attrs |= PVF_WRITE;
   2253 
   2254 		/* color conflict.  evict from cache. */
   2255 		pmap_flush_page(md, pa, PMAP_FLUSH_PRIMARY);
   2256 
   2257 		/* the list can't be empty because this was a enter/modify */
   2258 		pv = SLIST_FIRST(&md->pvh_list);
   2259 		if ((md->pvh_attrs & PVF_KMPAGE) == 0) {
   2260 			KASSERT(pv);
   2261 			/*
   2262 			 * If there's only one mapped page, change color to the
   2263 			 * page's new color and return.  Restore the DIRTY bit
   2264 			 * that was erased by pmap_flush_page.
   2265 			 */
   2266 			if (SLIST_NEXT(pv, pv_link) == NULL) {
   2267 				md->pvh_attrs &= PAGE_SIZE - 1;
   2268 				md->pvh_attrs |= (va & arm_cache_prefer_mask);
   2269 				if (md->pvh_attrs & PVF_DMOD)
   2270 					md->pvh_attrs |= PVF_DIRTY;
   2271 				PMAPCOUNT(vac_color_change);
   2272 				KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2273 				KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
   2274 				KASSERT(!(md->pvh_attrs & PVF_MULTCLR));
   2275 				return;
   2276 			}
   2277 		}
   2278 		bad_alias = true;
   2279 		md->pvh_attrs &= ~PVF_COLORED;
   2280 		md->pvh_attrs |= PVF_NC;
   2281 		PMAPCOUNT(vac_color_erase);
   2282 		KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   2283 	}
   2284 
   2285   fixup:
   2286 	KASSERT((rw_mappings == 0) == !(md->pvh_attrs & PVF_WRITE));
   2287 
   2288 	/*
   2289 	 * Turn cacheing on/off for all pages.
   2290 	 */
   2291 	SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
   2292 		struct l2_bucket * const l2b = pmap_get_l2_bucket(pv->pv_pmap,
   2293 		    pv->pv_va);
   2294 		KASSERTMSG(l2b != NULL, "%#lx", va);
   2295 		pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(pv->pv_va)];
   2296 		const pt_entry_t opte = *ptep;
   2297 		pt_entry_t npte = opte & ~L2_S_CACHE_MASK;
   2298 		if (bad_alias) {
   2299 			pv->pv_flags |= PVF_NC;
   2300 		} else {
   2301 			pv->pv_flags &= ~PVF_NC;
   2302 			npte |= pte_l2_s_cache_mode;
   2303 		}
   2304 
   2305 		if (opte == npte)	/* only update is there's a change */
   2306 			continue;
   2307 
   2308 		if (l2pte_valid_p(npte)) {
   2309 			pmap_tlb_flush_SE(pv->pv_pmap, pv->pv_va, pv->pv_flags);
   2310 		}
   2311 
   2312 		l2pte_set(ptep, npte, opte);
   2313 		PTE_SYNC_CURRENT(pv->pv_pmap, ptep);
   2314 	}
   2315 #endif /* !ARM_MMU_EXTENDED */
   2316 }
   2317 #endif	/* PMAP_CACHE_VIPT */
   2318 
   2319 
   2320 /*
   2321  * Modify pte bits for all ptes corresponding to the given physical address.
   2322  * We use `maskbits' rather than `clearbits' because we're always passing
   2323  * constants and the latter would require an extra inversion at run-time.
   2324  */
   2325 static void
   2326 pmap_clearbit(struct vm_page_md *md, paddr_t pa, u_int maskbits)
   2327 {
   2328 	struct pv_entry *pv;
   2329 #ifdef PMAP_CACHE_VIPT
   2330 	const bool want_syncicache = PV_IS_EXEC_P(md->pvh_attrs);
   2331 #ifdef ARM_MMU_EXTENDED
   2332 	const u_int execbits = (maskbits & PVF_EXEC) ? L2_XS_XN : 0;
   2333 #else
   2334 	const u_int execbits = 0;
   2335 	bool need_vac_me_harder = false;
   2336 	bool need_syncicache = false;
   2337 #endif
   2338 #else
   2339 	const u_int execbits = 0;
   2340 #endif
   2341 
   2342 	NPDEBUG(PDB_BITS,
   2343 	    printf("pmap_clearbit: md %p mask 0x%x\n",
   2344 	    md, maskbits));
   2345 
   2346 #ifdef PMAP_CACHE_VIPT
   2347 	/*
   2348 	 * If we might want to sync the I-cache and we've modified it,
   2349 	 * then we know we definitely need to sync or discard it.
   2350 	 */
   2351 	if (want_syncicache) {
   2352 #ifdef ARM_MMU_EXTENDED
   2353 		if (md->pvh_attrs & PVF_MOD)
   2354 			md->pvh_attrs &= ~PVF_EXEC;
   2355 #else
   2356 		need_syncicache = md->pvh_attrs & PVF_MOD;
   2357 #endif
   2358 	}
   2359 #endif
   2360 	KASSERT(pmap_page_locked_p(md));
   2361 
   2362 	/*
   2363 	 * Clear saved attributes (modify, reference)
   2364 	 */
   2365 	md->pvh_attrs &= ~(maskbits & (PVF_MOD | PVF_REF));
   2366 
   2367 	if (SLIST_EMPTY(&md->pvh_list)) {
   2368 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   2369 		if (need_syncicache) {
   2370 			/*
   2371 			 * No one has it mapped, so just discard it.  The next
   2372 			 * exec remapping will cause it to be synced.
   2373 			 */
   2374 			md->pvh_attrs &= ~PVF_EXEC;
   2375 			PMAPCOUNT(exec_discarded_clearbit);
   2376 		}
   2377 #endif
   2378 		return;
   2379 	}
   2380 
   2381 	/*
   2382 	 * Loop over all current mappings setting/clearing as appropos
   2383 	 */
   2384 	SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
   2385 		pmap_t pm = pv->pv_pmap;
   2386 		const vaddr_t va = pv->pv_va;
   2387 		const u_int oflags = pv->pv_flags;
   2388 #ifndef ARM_MMU_EXTENDED
   2389 		/*
   2390 		 * Kernel entries are unmanaged and as such not to be changed.
   2391 		 */
   2392 		if (PV_IS_KENTRY_P(oflags))
   2393 			continue;
   2394 #endif
   2395 		pv->pv_flags &= ~maskbits;
   2396 
   2397 		pmap_release_page_lock(md);
   2398 		pmap_acquire_pmap_lock(pm);
   2399 
   2400 		struct l2_bucket * const l2b = pmap_get_l2_bucket(pm, va);
   2401 		if (l2b == NULL) {
   2402 			pmap_release_pmap_lock(pm);
   2403 			pmap_acquire_page_lock(md);
   2404 			continue;
   2405 		}
   2406 		KASSERTMSG(l2b != NULL, "%#lx", va);
   2407 
   2408 		pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
   2409 		const pt_entry_t opte = *ptep;
   2410 		pt_entry_t npte = opte | execbits;
   2411 
   2412 #ifdef ARM_MMU_EXTENDED
   2413 		KASSERT((opte & L2_XS_nG) == (pm == pmap_kernel() ? 0 : L2_XS_nG));
   2414 #endif
   2415 
   2416 		NPDEBUG(PDB_BITS,
   2417 		    printf( "%s: pv %p, pm %p, va 0x%08lx, flag 0x%x\n",
   2418 			__func__, pv, pm, va, oflags));
   2419 
   2420 		if (maskbits & (PVF_WRITE|PVF_MOD)) {
   2421 #ifdef PMAP_CACHE_VIVT
   2422 			if ((oflags & PVF_NC)) {
   2423 				/*
   2424 				 * Entry is not cacheable:
   2425 				 *
   2426 				 * Don't turn caching on again if this is a
   2427 				 * modified emulation. This would be
   2428 				 * inconsitent with the settings created by
   2429 				 * pmap_vac_me_harder(). Otherwise, it's safe
   2430 				 * to re-enable cacheing.
   2431 				 *
   2432 				 * There's no need to call pmap_vac_me_harder()
   2433 				 * here: all pages are losing their write
   2434 				 * permission.
   2435 				 */
   2436 				if (maskbits & PVF_WRITE) {
   2437 					npte |= pte_l2_s_cache_mode;
   2438 					pv->pv_flags &= ~PVF_NC;
   2439 				}
   2440 			} else
   2441 			if (l2pte_writable_p(opte)) {
   2442 				/*
   2443 				 * Entry is writable/cacheable: check if pmap
   2444 				 * is current if it is flush it, otherwise it
   2445 				 * won't be in the cache
   2446 				 */
   2447 				pmap_cache_wbinv_page(pm, va,
   2448 				    (maskbits & PVF_REF) != 0,
   2449 				    oflags|PVF_WRITE);
   2450 			}
   2451 #endif
   2452 
   2453 			/* make the pte read only */
   2454 			npte = l2pte_set_readonly(npte);
   2455 
   2456 			pmap_acquire_page_lock(md);
   2457 #ifdef MULTIPROCESSOR
   2458 			pv = pmap_find_pv(md, pm, va);
   2459 #endif
   2460 			if (pv != NULL && (maskbits & oflags & PVF_WRITE)) {
   2461 				/*
   2462 				 * Keep alias accounting up to date
   2463 				 */
   2464 				if (pm == pmap_kernel()) {
   2465 					md->krw_mappings--;
   2466 					md->kro_mappings++;
   2467 				} else {
   2468 					md->urw_mappings--;
   2469 					md->uro_mappings++;
   2470 				}
   2471 #ifdef PMAP_CACHE_VIPT
   2472 				if (arm_cache_prefer_mask != 0) {
   2473 					if (md->urw_mappings + md->krw_mappings == 0) {
   2474 						md->pvh_attrs &= ~PVF_WRITE;
   2475 					} else {
   2476 						PMAP_VALIDATE_MD_PAGE(md);
   2477 					}
   2478 				}
   2479 #ifndef ARM_MMU_EXTENDED
   2480 				if (want_syncicache)
   2481 					need_syncicache = true;
   2482 				need_vac_me_harder = true;
   2483 #endif
   2484 #endif /* PMAP_CACHE_VIPT */
   2485 			}
   2486 			pmap_release_page_lock(md);
   2487 		}
   2488 
   2489 		if (maskbits & PVF_REF) {
   2490 			if (true
   2491 #ifndef ARM_MMU_EXTENDED
   2492 			    && (oflags & PVF_NC) == 0
   2493 #endif
   2494 			    && (maskbits & (PVF_WRITE|PVF_MOD)) == 0
   2495 			    && l2pte_valid_p(npte)) {
   2496 #ifdef PMAP_CACHE_VIVT
   2497 				/*
   2498 				 * Check npte here; we may have already
   2499 				 * done the wbinv above, and the validity
   2500 				 * of the PTE is the same for opte and
   2501 				 * npte.
   2502 				 */
   2503 				pmap_cache_wbinv_page(pm, va, true, oflags);
   2504 #endif
   2505 			}
   2506 
   2507 			/*
   2508 			 * Make the PTE invalid so that we will take a
   2509 			 * page fault the next time the mapping is
   2510 			 * referenced.
   2511 			 */
   2512 			npte &= ~L2_TYPE_MASK;
   2513 			npte |= L2_TYPE_INV;
   2514 		}
   2515 
   2516 		if (npte != opte) {
   2517 			l2pte_reset(ptep);
   2518 			PTE_SYNC(ptep);
   2519 
   2520 			/* Flush the TLB entry if a current pmap. */
   2521 			pmap_tlb_flush_SE(pm, va, oflags);
   2522 
   2523 			l2pte_set(ptep, npte, 0);
   2524 			PTE_SYNC(ptep);
   2525 		}
   2526 
   2527 		pmap_release_pmap_lock(pm);
   2528 		pmap_acquire_page_lock(md);
   2529 
   2530 		NPDEBUG(PDB_BITS,
   2531 		    printf("pmap_clearbit: pm %p va 0x%lx opte 0x%08x npte 0x%08x\n",
   2532 		    pm, va, opte, npte));
   2533 	}
   2534 
   2535 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   2536 	/*
   2537 	 * If we need to sync the I-cache and we haven't done it yet, do it.
   2538 	 */
   2539 	if (need_syncicache) {
   2540 		pmap_release_page_lock(md);
   2541 		pmap_syncicache_page(md, pa);
   2542 		pmap_acquire_page_lock(md);
   2543 		PMAPCOUNT(exec_synced_clearbit);
   2544 	}
   2545 
   2546 	/*
   2547 	 * If we are changing this to read-only, we need to call vac_me_harder
   2548 	 * so we can change all the read-only pages to cacheable.  We pretend
   2549 	 * this as a page deletion.
   2550 	 */
   2551 	if (need_vac_me_harder) {
   2552 		if (md->pvh_attrs & PVF_NC)
   2553 			pmap_vac_me_harder(md, pa, NULL, 0);
   2554 	}
   2555 #endif /* PMAP_CACHE_VIPT && !ARM_MMU_EXTENDED */
   2556 }
   2557 
   2558 /*
   2559  * pmap_clean_page()
   2560  *
   2561  * This is a local function used to work out the best strategy to clean
   2562  * a single page referenced by its entry in the PV table. It's used by
   2563  * pmap_copy_page, pmap_zero_page and maybe some others later on.
   2564  *
   2565  * Its policy is effectively:
   2566  *  o If there are no mappings, we don't bother doing anything with the cache.
   2567  *  o If there is one mapping, we clean just that page.
   2568  *  o If there are multiple mappings, we clean the entire cache.
   2569  *
   2570  * So that some functions can be further optimised, it returns 0 if it didn't
   2571  * clean the entire cache, or 1 if it did.
   2572  *
   2573  * XXX One bug in this routine is that if the pv_entry has a single page
   2574  * mapped at 0x00000000 a whole cache clean will be performed rather than
   2575  * just the 1 page. Since this should not occur in everyday use and if it does
   2576  * it will just result in not the most efficient clean for the page.
   2577  */
   2578 #ifdef PMAP_CACHE_VIVT
   2579 static bool
   2580 pmap_clean_page(struct vm_page_md *md, bool is_src)
   2581 {
   2582 	struct pv_entry *pv;
   2583 	pmap_t pm_to_clean = NULL;
   2584 	bool cache_needs_cleaning = false;
   2585 	vaddr_t page_to_clean = 0;
   2586 	u_int flags = 0;
   2587 
   2588 	/*
   2589 	 * Since we flush the cache each time we change to a different
   2590 	 * user vmspace, we only need to flush the page if it is in the
   2591 	 * current pmap.
   2592 	 */
   2593 	KASSERT(pmap_page_locked_p(md));
   2594 	SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
   2595 		if (pmap_is_current(pv->pv_pmap)) {
   2596 			flags |= pv->pv_flags;
   2597 			/*
   2598 			 * The page is mapped non-cacheable in
   2599 			 * this map.  No need to flush the cache.
   2600 			 */
   2601 			if (pv->pv_flags & PVF_NC) {
   2602 #ifdef DIAGNOSTIC
   2603 				KASSERT(!cache_needs_cleaning);
   2604 #endif
   2605 				break;
   2606 			} else if (is_src && (pv->pv_flags & PVF_WRITE) == 0)
   2607 				continue;
   2608 			if (cache_needs_cleaning) {
   2609 				page_to_clean = 0;
   2610 				break;
   2611 			} else {
   2612 				page_to_clean = pv->pv_va;
   2613 				pm_to_clean = pv->pv_pmap;
   2614 			}
   2615 			cache_needs_cleaning = true;
   2616 		}
   2617 	}
   2618 
   2619 	if (page_to_clean) {
   2620 		pmap_cache_wbinv_page(pm_to_clean, page_to_clean,
   2621 		    !is_src, flags | PVF_REF);
   2622 	} else if (cache_needs_cleaning) {
   2623 		pmap_t const pm = curproc->p_vmspace->vm_map.pmap;
   2624 
   2625 		pmap_cache_wbinv_all(pm, flags);
   2626 		return true;
   2627 	}
   2628 	return false;
   2629 }
   2630 #endif
   2631 
   2632 #ifdef PMAP_CACHE_VIPT
   2633 /*
   2634  * Sync a page with the I-cache.  Since this is a VIPT, we must pick the
   2635  * right cache alias to make sure we flush the right stuff.
   2636  */
   2637 void
   2638 pmap_syncicache_page(struct vm_page_md *md, paddr_t pa)
   2639 {
   2640 	pmap_t kpm = pmap_kernel();
   2641 	const size_t way_size = arm_pcache.icache_type == CACHE_TYPE_PIPT
   2642 	    ? PAGE_SIZE
   2643 	    : arm_pcache.icache_way_size;
   2644 
   2645 	NPDEBUG(PDB_EXEC, printf("pmap_syncicache_page: md=%p (attrs=%#x)\n",
   2646 	    md, md->pvh_attrs));
   2647 	/*
   2648 	 * No need to clean the page if it's non-cached.
   2649 	 */
   2650 #ifndef ARM_MMU_EXTENDED
   2651 	if (md->pvh_attrs & PVF_NC)
   2652 		return;
   2653 	KASSERT(arm_cache_prefer_mask == 0 || md->pvh_attrs & PVF_COLORED);
   2654 #endif
   2655 
   2656 	pt_entry_t * const ptep = cpu_cdst_pte(0);
   2657 	const vaddr_t dstp = cpu_cdstp(0);
   2658 #ifdef __HAVE_MM_MD_DIRECT_MAPPED_PHYS
   2659 	if (way_size <= PAGE_SIZE) {
   2660 		bool ok = false;
   2661 		vaddr_t vdstp = pmap_direct_mapped_phys(pa, &ok, dstp);
   2662 		if (ok) {
   2663 			cpu_icache_sync_range(vdstp, way_size);
   2664 			return;
   2665 		}
   2666 	}
   2667 #endif
   2668 
   2669 	/*
   2670 	 * We don't worry about the color of the exec page, we map the
   2671 	 * same page to pages in the way and then do the icache_sync on
   2672 	 * the entire way making sure we are cleaned.
   2673 	 */
   2674 	const pt_entry_t npte = L2_S_PROTO | pa | pte_l2_s_cache_mode
   2675 	    | L2_S_PROT(PTE_KERNEL, VM_PROT_READ|VM_PROT_WRITE);
   2676 
   2677 	for (size_t i = 0, j = 0; i < way_size;
   2678 	     i += PAGE_SIZE, j += PAGE_SIZE / L2_S_SIZE) {
   2679 		l2pte_reset(ptep + j);
   2680 		PTE_SYNC(ptep + j);
   2681 
   2682 		pmap_tlb_flush_SE(kpm, dstp + i, PVF_REF | PVF_EXEC);
   2683 		/*
   2684 		 * Set up a PTE with to flush these cache lines.
   2685 		 */
   2686 		l2pte_set(ptep + j, npte, 0);
   2687 	}
   2688 	PTE_SYNC_RANGE(ptep, way_size / L2_S_SIZE);
   2689 
   2690 	/*
   2691 	 * Flush it.
   2692 	 */
   2693 	cpu_icache_sync_range(dstp, way_size);
   2694 
   2695 	for (size_t i = 0, j = 0; i < way_size;
   2696 	     i += PAGE_SIZE, j += PAGE_SIZE / L2_S_SIZE) {
   2697 		/*
   2698 		 * Unmap the page(s).
   2699 		 */
   2700 		l2pte_reset(ptep + j);
   2701 		pmap_tlb_flush_SE(kpm, dstp + i, PVF_REF | PVF_EXEC);
   2702 	}
   2703 	PTE_SYNC_RANGE(ptep, way_size / L2_S_SIZE);
   2704 
   2705 	md->pvh_attrs |= PVF_EXEC;
   2706 	PMAPCOUNT(exec_synced);
   2707 }
   2708 
   2709 #ifndef ARM_MMU_EXTENDED
   2710 void
   2711 pmap_flush_page(struct vm_page_md *md, paddr_t pa, enum pmap_flush_op flush)
   2712 {
   2713 	vsize_t va_offset, end_va;
   2714 	bool wbinv_p;
   2715 
   2716 	if (arm_cache_prefer_mask == 0)
   2717 		return;
   2718 
   2719 	switch (flush) {
   2720 	case PMAP_FLUSH_PRIMARY:
   2721 		if (md->pvh_attrs & PVF_MULTCLR) {
   2722 			va_offset = 0;
   2723 			end_va = arm_cache_prefer_mask;
   2724 			md->pvh_attrs &= ~PVF_MULTCLR;
   2725 			PMAPCOUNT(vac_flush_lots);
   2726 		} else {
   2727 			va_offset = md->pvh_attrs & arm_cache_prefer_mask;
   2728 			end_va = va_offset;
   2729 			PMAPCOUNT(vac_flush_one);
   2730 		}
   2731 		/*
   2732 		 * Mark that the page is no longer dirty.
   2733 		 */
   2734 		md->pvh_attrs &= ~PVF_DIRTY;
   2735 		wbinv_p = true;
   2736 		break;
   2737 	case PMAP_FLUSH_SECONDARY:
   2738 		va_offset = 0;
   2739 		end_va = arm_cache_prefer_mask;
   2740 		wbinv_p = true;
   2741 		md->pvh_attrs &= ~PVF_MULTCLR;
   2742 		PMAPCOUNT(vac_flush_lots);
   2743 		break;
   2744 	case PMAP_CLEAN_PRIMARY:
   2745 		va_offset = md->pvh_attrs & arm_cache_prefer_mask;
   2746 		end_va = va_offset;
   2747 		wbinv_p = false;
   2748 		/*
   2749 		 * Mark that the page is no longer dirty.
   2750 		 */
   2751 		if ((md->pvh_attrs & PVF_DMOD) == 0)
   2752 			md->pvh_attrs &= ~PVF_DIRTY;
   2753 		PMAPCOUNT(vac_clean_one);
   2754 		break;
   2755 	default:
   2756 		return;
   2757 	}
   2758 
   2759 	KASSERT(!(md->pvh_attrs & PVF_NC));
   2760 
   2761 	NPDEBUG(PDB_VAC, printf("pmap_flush_page: md=%p (attrs=%#x)\n",
   2762 	    md, md->pvh_attrs));
   2763 
   2764 	const size_t scache_line_size = arm_scache.dcache_line_size;
   2765 
   2766 	for (; va_offset <= end_va; va_offset += PAGE_SIZE) {
   2767 		pt_entry_t * const ptep = cpu_cdst_pte(va_offset);
   2768 		const vaddr_t dstp = cpu_cdstp(va_offset);
   2769 		const pt_entry_t opte = *ptep;
   2770 
   2771 		if (flush == PMAP_FLUSH_SECONDARY
   2772 		    && va_offset == (md->pvh_attrs & arm_cache_prefer_mask))
   2773 			continue;
   2774 
   2775 		pmap_tlb_flush_SE(pmap_kernel(), dstp, PVF_REF | PVF_EXEC);
   2776 		/*
   2777 		 * Set up a PTE with the right coloring to flush
   2778 		 * existing cache entries.
   2779 		 */
   2780 		const pt_entry_t npte = L2_S_PROTO
   2781 		    | pa
   2782 		    | L2_S_PROT(PTE_KERNEL, VM_PROT_READ|VM_PROT_WRITE)
   2783 		    | pte_l2_s_cache_mode;
   2784 		l2pte_set(ptep, npte, opte);
   2785 		PTE_SYNC(ptep);
   2786 
   2787 		/*
   2788 		 * Flush it.  Make sure to flush secondary cache too since
   2789 		 * bus_dma will ignore uncached pages.
   2790 		 */
   2791 		if (scache_line_size != 0) {
   2792 			cpu_dcache_wb_range(dstp, PAGE_SIZE);
   2793 			if (wbinv_p) {
   2794 				cpu_sdcache_wbinv_range(dstp, pa, PAGE_SIZE);
   2795 				cpu_dcache_inv_range(dstp, PAGE_SIZE);
   2796 			} else {
   2797 				cpu_sdcache_wb_range(dstp, pa, PAGE_SIZE);
   2798 			}
   2799 		} else {
   2800 			if (wbinv_p) {
   2801 				cpu_dcache_wbinv_range(dstp, PAGE_SIZE);
   2802 			} else {
   2803 				cpu_dcache_wb_range(dstp, PAGE_SIZE);
   2804 			}
   2805 		}
   2806 
   2807 		/*
   2808 		 * Restore the page table entry since we might have interrupted
   2809 		 * pmap_zero_page or pmap_copy_page which was already using
   2810 		 * this pte.
   2811 		 */
   2812 		if (opte) {
   2813 			l2pte_set(ptep, opte, npte);
   2814 		} else {
   2815 			l2pte_reset(ptep);
   2816 		}
   2817 		PTE_SYNC(ptep);
   2818 		pmap_tlb_flush_SE(pmap_kernel(), dstp, PVF_REF | PVF_EXEC);
   2819 	}
   2820 }
   2821 #endif /* ARM_MMU_EXTENDED */
   2822 #endif /* PMAP_CACHE_VIPT */
   2823 
   2824 /*
   2825  * Routine:	pmap_page_remove
   2826  * Function:
   2827  *		Removes this physical page from
   2828  *		all physical maps in which it resides.
   2829  *		Reflects back modify bits to the pager.
   2830  */
   2831 static void
   2832 pmap_page_remove(struct vm_page_md *md, paddr_t pa)
   2833 {
   2834 	struct l2_bucket *l2b;
   2835 	struct pv_entry *pv;
   2836 	pt_entry_t *ptep;
   2837 #ifndef ARM_MMU_EXTENDED
   2838 	bool flush = false;
   2839 #endif
   2840 	u_int flags = 0;
   2841 
   2842 	NPDEBUG(PDB_FOLLOW,
   2843 	    printf("pmap_page_remove: md %p (0x%08lx)\n", md,
   2844 	    pa));
   2845 
   2846 	struct pv_entry **pvp = &SLIST_FIRST(&md->pvh_list);
   2847 	pmap_acquire_page_lock(md);
   2848 	if (*pvp == NULL) {
   2849 #ifdef PMAP_CACHE_VIPT
   2850 		/*
   2851 		 * We *know* the page contents are about to be replaced.
   2852 		 * Discard the exec contents
   2853 		 */
   2854 		if (PV_IS_EXEC_P(md->pvh_attrs))
   2855 			PMAPCOUNT(exec_discarded_page_protect);
   2856 		md->pvh_attrs &= ~PVF_EXEC;
   2857 		PMAP_VALIDATE_MD_PAGE(md);
   2858 #endif
   2859 		pmap_release_page_lock(md);
   2860 		return;
   2861 	}
   2862 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   2863 	KASSERT(arm_cache_prefer_mask == 0 || pmap_is_page_colored_p(md));
   2864 #endif
   2865 
   2866 	/*
   2867 	 * Clear alias counts
   2868 	 */
   2869 #ifdef PMAP_CACHE_VIVT
   2870 	md->k_mappings = 0;
   2871 #endif
   2872 	md->urw_mappings = md->uro_mappings = 0;
   2873 
   2874 #ifdef PMAP_CACHE_VIVT
   2875 	pmap_clean_page(md, false);
   2876 #endif
   2877 
   2878 	while ((pv = *pvp) != NULL) {
   2879 		pmap_t pm = pv->pv_pmap;
   2880 #ifndef ARM_MMU_EXTENDED
   2881 		if (flush == false && pmap_is_current(pm))
   2882 			flush = true;
   2883 #endif
   2884 
   2885 		if (pm == pmap_kernel()) {
   2886 #ifdef PMAP_CACHE_VIPT
   2887 			/*
   2888 			 * If this was unmanaged mapping, it must be preserved.
   2889 			 * Move it back on the list and advance the end-of-list
   2890 			 * pointer.
   2891 			 */
   2892 			if (PV_IS_KENTRY_P(pv->pv_flags)) {
   2893 				*pvp = pv;
   2894 				pvp = &SLIST_NEXT(pv, pv_link);
   2895 				continue;
   2896 			}
   2897 			if (pv->pv_flags & PVF_WRITE)
   2898 				md->krw_mappings--;
   2899 			else
   2900 				md->kro_mappings--;
   2901 #endif
   2902 			PMAPCOUNT(kernel_unmappings);
   2903 		}
   2904 		*pvp = SLIST_NEXT(pv, pv_link); /* remove from list */
   2905 		PMAPCOUNT(unmappings);
   2906 
   2907 		pmap_release_page_lock(md);
   2908 		pmap_acquire_pmap_lock(pm);
   2909 
   2910 		l2b = pmap_get_l2_bucket(pm, pv->pv_va);
   2911 		KASSERTMSG(l2b != NULL, "%#lx", pv->pv_va);
   2912 
   2913 		ptep = &l2b->l2b_kva[l2pte_index(pv->pv_va)];
   2914 
   2915 		/*
   2916 		 * Update statistics
   2917 		 */
   2918 		--pm->pm_stats.resident_count;
   2919 
   2920 		/* Wired bit */
   2921 		if (pv->pv_flags & PVF_WIRED)
   2922 			--pm->pm_stats.wired_count;
   2923 
   2924 		flags |= pv->pv_flags;
   2925 
   2926 		/*
   2927 		 * Invalidate the PTEs.
   2928 		 */
   2929 		l2pte_reset(ptep);
   2930 		PTE_SYNC_CURRENT(pm, ptep);
   2931 
   2932 #ifdef ARM_MMU_EXTENDED
   2933 		pmap_tlb_invalidate_addr(pm, pv->pv_va);
   2934 #endif
   2935 
   2936 		pmap_free_l2_bucket(pm, l2b, PAGE_SIZE / L2_S_SIZE);
   2937 
   2938 		pmap_release_pmap_lock(pm);
   2939 
   2940 		pool_put(&pmap_pv_pool, pv);
   2941 		pmap_acquire_page_lock(md);
   2942 #ifdef MULTIPROCESSOR
   2943 		/*
   2944 		 * Restart of the beginning of the list.
   2945 		 */
   2946 		pvp = &SLIST_FIRST(&md->pvh_list);
   2947 #endif
   2948 	}
   2949 	/*
   2950 	 * if we reach the end of the list and there are still mappings, they
   2951 	 * might be able to be cached now.  And they must be kernel mappings.
   2952 	 */
   2953 	if (!SLIST_EMPTY(&md->pvh_list)) {
   2954 		pmap_vac_me_harder(md, pa, pmap_kernel(), 0);
   2955 	}
   2956 
   2957 #ifdef PMAP_CACHE_VIPT
   2958 	/*
   2959 	 * Its EXEC cache is now gone.
   2960 	 */
   2961 	if (PV_IS_EXEC_P(md->pvh_attrs))
   2962 		PMAPCOUNT(exec_discarded_page_protect);
   2963 	md->pvh_attrs &= ~PVF_EXEC;
   2964 	KASSERT(md->urw_mappings == 0);
   2965 	KASSERT(md->uro_mappings == 0);
   2966 #ifndef ARM_MMU_EXTENDED
   2967 	if (arm_cache_prefer_mask != 0) {
   2968 		if (md->krw_mappings == 0)
   2969 			md->pvh_attrs &= ~PVF_WRITE;
   2970 		PMAP_VALIDATE_MD_PAGE(md);
   2971 	}
   2972 #endif /* ARM_MMU_EXTENDED */
   2973 #endif /* PMAP_CACHE_VIPT */
   2974 	pmap_release_page_lock(md);
   2975 
   2976 #ifndef ARM_MMU_EXTENDED
   2977 	if (flush) {
   2978 		/*
   2979 		 * Note: We can't use pmap_tlb_flush{I,D}() here since that
   2980 		 * would need a subsequent call to pmap_update() to ensure
   2981 		 * curpm->pm_cstate.cs_all is reset. Our callers are not
   2982 		 * required to do that (see pmap(9)), so we can't modify
   2983 		 * the current pmap's state.
   2984 		 */
   2985 		if (PV_BEEN_EXECD(flags))
   2986 			cpu_tlb_flushID();
   2987 		else
   2988 			cpu_tlb_flushD();
   2989 	}
   2990 	cpu_cpwait();
   2991 #endif /* ARM_MMU_EXTENDED */
   2992 }
   2993 
   2994 /*
   2995  * pmap_t pmap_create(void)
   2996  *
   2997  *      Create a new pmap structure from scratch.
   2998  */
   2999 pmap_t
   3000 pmap_create(void)
   3001 {
   3002 	pmap_t pm;
   3003 
   3004 	pm = pool_cache_get(&pmap_cache, PR_WAITOK);
   3005 
   3006 	mutex_init(&pm->pm_obj_lock, MUTEX_DEFAULT, IPL_NONE);
   3007 	uvm_obj_init(&pm->pm_obj, NULL, false, 1);
   3008 	uvm_obj_setlock(&pm->pm_obj, &pm->pm_obj_lock);
   3009 
   3010 	pm->pm_stats.wired_count = 0;
   3011 	pm->pm_stats.resident_count = 1;
   3012 #ifdef ARM_MMU_EXTENDED
   3013 #ifdef MULTIPROCESSOR
   3014 	kcpuset_create(&pm->pm_active, true);
   3015 	kcpuset_create(&pm->pm_onproc, true);
   3016 #endif
   3017 #else
   3018 	pm->pm_cstate.cs_all = 0;
   3019 #endif
   3020 	pmap_alloc_l1(pm);
   3021 
   3022 	/*
   3023 	 * Note: The pool cache ensures that the pm_l2[] array is already
   3024 	 * initialised to zero.
   3025 	 */
   3026 
   3027 	pmap_pinit(pm);
   3028 
   3029 	return (pm);
   3030 }
   3031 
   3032 u_int
   3033 arm32_mmap_flags(paddr_t pa)
   3034 {
   3035 	/*
   3036 	 * the upper 8 bits in pmap_enter()'s flags are reserved for MD stuff
   3037 	 * and we're using the upper bits in page numbers to pass flags around
   3038 	 * so we might as well use the same bits
   3039 	 */
   3040 	return (u_int)pa & PMAP_MD_MASK;
   3041 }
   3042 /*
   3043  * int pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot,
   3044  *      u_int flags)
   3045  *
   3046  *      Insert the given physical page (p) at
   3047  *      the specified virtual address (v) in the
   3048  *      target physical map with the protection requested.
   3049  *
   3050  *      NB:  This is the only routine which MAY NOT lazy-evaluate
   3051  *      or lose information.  That is, this routine must actually
   3052  *      insert this page into the given map NOW.
   3053  */
   3054 int
   3055 pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot, u_int flags)
   3056 {
   3057 	struct l2_bucket *l2b;
   3058 	struct vm_page *pg, *opg;
   3059 	u_int nflags;
   3060 	u_int oflags;
   3061 	const bool kpm_p = (pm == pmap_kernel());
   3062 #ifdef ARM_HAS_VBAR
   3063 	const bool vector_page_p = false;
   3064 #else
   3065 	const bool vector_page_p = (va == vector_page);
   3066 #endif
   3067 
   3068 	UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
   3069 
   3070 	UVMHIST_LOG(maphist, " (pm %p va %#x pa %#x prot %#x",
   3071 	    pm, va, pa, prot);
   3072 	UVMHIST_LOG(maphist, "  flag %#x", flags, 0, 0, 0);
   3073 
   3074 	KDASSERT((flags & PMAP_WIRED) == 0 || (flags & VM_PROT_ALL) != 0);
   3075 	KDASSERT(((va | pa) & PGOFSET) == 0);
   3076 
   3077 	/*
   3078 	 * Get a pointer to the page.  Later on in this function, we
   3079 	 * test for a managed page by checking pg != NULL.
   3080 	 */
   3081 	pg = pmap_initialized ? PHYS_TO_VM_PAGE(pa) : NULL;
   3082 
   3083 	nflags = 0;
   3084 	if (prot & VM_PROT_WRITE)
   3085 		nflags |= PVF_WRITE;
   3086 	if (prot & VM_PROT_EXECUTE)
   3087 		nflags |= PVF_EXEC;
   3088 	if (flags & PMAP_WIRED)
   3089 		nflags |= PVF_WIRED;
   3090 
   3091 	pmap_acquire_pmap_lock(pm);
   3092 
   3093 	/*
   3094 	 * Fetch the L2 bucket which maps this page, allocating one if
   3095 	 * necessary for user pmaps.
   3096 	 */
   3097 	if (kpm_p) {
   3098 		l2b = pmap_get_l2_bucket(pm, va);
   3099 	} else {
   3100 		l2b = pmap_alloc_l2_bucket(pm, va);
   3101 	}
   3102 	if (l2b == NULL) {
   3103 		if (flags & PMAP_CANFAIL) {
   3104 			pmap_release_pmap_lock(pm);
   3105 			return (ENOMEM);
   3106 		}
   3107 		panic("pmap_enter: failed to allocate L2 bucket");
   3108 	}
   3109 	pt_entry_t *ptep = &l2b->l2b_kva[l2pte_index(va)];
   3110 	const pt_entry_t opte = *ptep;
   3111 	pt_entry_t npte = pa;
   3112 	oflags = 0;
   3113 
   3114 	if (opte) {
   3115 		/*
   3116 		 * There is already a mapping at this address.
   3117 		 * If the physical address is different, lookup the
   3118 		 * vm_page.
   3119 		 */
   3120 		if (l2pte_pa(opte) != pa) {
   3121 			KASSERT(!pmap_pv_tracked(pa));
   3122 			opg = PHYS_TO_VM_PAGE(l2pte_pa(opte));
   3123 		} else
   3124 			opg = pg;
   3125 	} else
   3126 		opg = NULL;
   3127 
   3128 	struct pmap_page *pp = pmap_pv_tracked(pa);
   3129 
   3130 	if (pg || pp) {
   3131 		KASSERT((pg != NULL) != (pp != NULL));
   3132 		struct vm_page_md *md = (pg != NULL) ? VM_PAGE_TO_MD(pg) :
   3133 		    PMAP_PAGE_TO_MD(pp);
   3134 
   3135 		/*
   3136 		 * This is to be a managed mapping.
   3137 		 */
   3138 		pmap_acquire_page_lock(md);
   3139 		if ((flags & VM_PROT_ALL) || (md->pvh_attrs & PVF_REF)) {
   3140 			/*
   3141 			 * - The access type indicates that we don't need
   3142 			 *   to do referenced emulation.
   3143 			 * OR
   3144 			 * - The physical page has already been referenced
   3145 			 *   so no need to re-do referenced emulation here.
   3146 			 */
   3147 			npte |= l2pte_set_readonly(L2_S_PROTO);
   3148 
   3149 			nflags |= PVF_REF;
   3150 
   3151 			if ((prot & VM_PROT_WRITE) != 0 &&
   3152 			    ((flags & VM_PROT_WRITE) != 0 ||
   3153 			     (md->pvh_attrs & PVF_MOD) != 0)) {
   3154 				/*
   3155 				 * This is a writable mapping, and the
   3156 				 * page's mod state indicates it has
   3157 				 * already been modified. Make it
   3158 				 * writable from the outset.
   3159 				 */
   3160 				npte = l2pte_set_writable(npte);
   3161 				nflags |= PVF_MOD;
   3162 			}
   3163 
   3164 #ifdef ARM_MMU_EXTENDED
   3165 			/*
   3166 			 * If the page has been cleaned, then the pvh_attrs
   3167 			 * will have PVF_EXEC set, so mark it execute so we
   3168 			 * don't get an access fault when trying to execute
   3169 			 * from it.
   3170 			 */
   3171 			if (md->pvh_attrs & nflags & PVF_EXEC) {
   3172 				npte &= ~L2_XS_XN;
   3173 			}
   3174 #endif
   3175 		} else {
   3176 			/*
   3177 			 * Need to do page referenced emulation.
   3178 			 */
   3179 			npte |= L2_TYPE_INV;
   3180 		}
   3181 
   3182 		if (flags & ARM32_MMAP_WRITECOMBINE) {
   3183 			npte |= pte_l2_s_wc_mode;
   3184 		} else
   3185 			npte |= pte_l2_s_cache_mode;
   3186 
   3187 		if (pg != NULL && pg == opg) {
   3188 			/*
   3189 			 * We're changing the attrs of an existing mapping.
   3190 			 */
   3191 			oflags = pmap_modify_pv(md, pa, pm, va,
   3192 			    PVF_WRITE | PVF_EXEC | PVF_WIRED |
   3193 			    PVF_MOD | PVF_REF, nflags);
   3194 
   3195 #ifdef PMAP_CACHE_VIVT
   3196 			/*
   3197 			 * We may need to flush the cache if we're
   3198 			 * doing rw-ro...
   3199 			 */
   3200 			if (pm->pm_cstate.cs_cache_d &&
   3201 			    (oflags & PVF_NC) == 0 &&
   3202 			    l2pte_writable_p(opte) &&
   3203 			    (prot & VM_PROT_WRITE) == 0)
   3204 				cpu_dcache_wb_range(va, PAGE_SIZE);
   3205 #endif
   3206 		} else {
   3207 			struct pv_entry *pv;
   3208 			/*
   3209 			 * New mapping, or changing the backing page
   3210 			 * of an existing mapping.
   3211 			 */
   3212 			if (opg) {
   3213 				struct vm_page_md *omd = VM_PAGE_TO_MD(opg);
   3214 				paddr_t opa = VM_PAGE_TO_PHYS(opg);
   3215 
   3216 				/*
   3217 				 * Replacing an existing mapping with a new one.
   3218 				 * It is part of our managed memory so we
   3219 				 * must remove it from the PV list
   3220 				 */
   3221 				pv = pmap_remove_pv(omd, opa, pm, va);
   3222 				pmap_vac_me_harder(omd, opa, pm, 0);
   3223 				oflags = pv->pv_flags;
   3224 
   3225 #ifdef PMAP_CACHE_VIVT
   3226 				/*
   3227 				 * If the old mapping was valid (ref/mod
   3228 				 * emulation creates 'invalid' mappings
   3229 				 * initially) then make sure to frob
   3230 				 * the cache.
   3231 				 */
   3232 				if (!(oflags & PVF_NC) && l2pte_valid_p(opte)) {
   3233 					pmap_cache_wbinv_page(pm, va, true,
   3234 					    oflags);
   3235 				}
   3236 #endif
   3237 			} else {
   3238 				pmap_release_page_lock(md);
   3239 				pv = pool_get(&pmap_pv_pool, PR_NOWAIT);
   3240 				if (pv == NULL) {
   3241 					pmap_release_pmap_lock(pm);
   3242 					if ((flags & PMAP_CANFAIL) == 0)
   3243 						panic("pmap_enter: "
   3244 						    "no pv entries");
   3245 
   3246 					pmap_free_l2_bucket(pm, l2b, 0);
   3247 					UVMHIST_LOG(maphist, "  <-- done (ENOMEM)",
   3248 					    0, 0, 0, 0);
   3249 					return (ENOMEM);
   3250 				}
   3251 				pmap_acquire_page_lock(md);
   3252 			}
   3253 
   3254 			pmap_enter_pv(md, pa, pv, pm, va, nflags);
   3255 		}
   3256 		pmap_release_page_lock(md);
   3257 	} else {
   3258 		/*
   3259 		 * We're mapping an unmanaged page.
   3260 		 * These are always readable, and possibly writable, from
   3261 		 * the get go as we don't need to track ref/mod status.
   3262 		 */
   3263 		npte |= l2pte_set_readonly(L2_S_PROTO);
   3264 		if (prot & VM_PROT_WRITE)
   3265 			npte = l2pte_set_writable(npte);
   3266 
   3267 		/*
   3268 		 * Make sure the vector table is mapped cacheable
   3269 		 */
   3270 		if ((vector_page_p && !kpm_p)
   3271 		    || (flags & ARM32_MMAP_CACHEABLE)) {
   3272 			npte |= pte_l2_s_cache_mode;
   3273 #ifdef ARM_MMU_EXTENDED
   3274 			npte &= ~L2_XS_XN;	/* and executable */
   3275 #endif
   3276 		} else if (flags & ARM32_MMAP_WRITECOMBINE) {
   3277 			npte |= pte_l2_s_wc_mode;
   3278 		}
   3279 		if (opg) {
   3280 			/*
   3281 			 * Looks like there's an existing 'managed' mapping
   3282 			 * at this address.
   3283 			 */
   3284 			struct vm_page_md *omd = VM_PAGE_TO_MD(opg);
   3285 			paddr_t opa = VM_PAGE_TO_PHYS(opg);
   3286 
   3287 			pmap_acquire_page_lock(omd);
   3288 			struct pv_entry *pv = pmap_remove_pv(omd, opa, pm, va);
   3289 			pmap_vac_me_harder(omd, opa, pm, 0);
   3290 			oflags = pv->pv_flags;
   3291 			pmap_release_page_lock(omd);
   3292 
   3293 #ifdef PMAP_CACHE_VIVT
   3294 			if (!(oflags & PVF_NC) && l2pte_valid_p(opte)) {
   3295 				pmap_cache_wbinv_page(pm, va, true, oflags);
   3296 			}
   3297 #endif
   3298 			pool_put(&pmap_pv_pool, pv);
   3299 		}
   3300 	}
   3301 
   3302 	/*
   3303 	 * Make sure userland mappings get the right permissions
   3304 	 */
   3305 	if (!vector_page_p && !kpm_p) {
   3306 		npte |= L2_S_PROT_U;
   3307 #ifdef ARM_MMU_EXTENDED
   3308 		npte |= L2_XS_nG;	/* user pages are not global */
   3309 #endif
   3310 	}
   3311 
   3312 	/*
   3313 	 * Keep the stats up to date
   3314 	 */
   3315 	if (opte == 0) {
   3316 		l2b->l2b_occupancy += PAGE_SIZE / L2_S_SIZE;
   3317 		pm->pm_stats.resident_count++;
   3318 	}
   3319 
   3320 	UVMHIST_LOG(maphist, " opte %#x npte %#x", opte, npte, 0, 0);
   3321 
   3322 #if defined(ARM_MMU_EXTENDED)
   3323 	/*
   3324 	 * If exec protection was requested but the page hasn't been synced,
   3325 	 * sync it now and allow execution from it.
   3326 	 */
   3327 	if ((nflags & PVF_EXEC) && (npte & L2_XS_XN)) {
   3328 		struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   3329 		npte &= ~L2_XS_XN;
   3330 		pmap_syncicache_page(md, pa);
   3331 		PMAPCOUNT(exec_synced_map);
   3332 	}
   3333 #endif
   3334 	/*
   3335 	 * If this is just a wiring change, the two PTEs will be
   3336 	 * identical, so there's no need to update the page table.
   3337 	 */
   3338 	if (npte != opte) {
   3339 		l2pte_reset(ptep);
   3340 		PTE_SYNC(ptep);
   3341 		if (l2pte_valid_p(opte)) {
   3342 			pmap_tlb_flush_SE(pm, va, oflags);
   3343 		}
   3344 		l2pte_set(ptep, npte, 0);
   3345 		PTE_SYNC(ptep);
   3346 #ifndef ARM_MMU_EXTENDED
   3347 		bool is_cached = pmap_is_cached(pm);
   3348 		if (is_cached) {
   3349 			/*
   3350 			 * We only need to frob the cache/tlb if this pmap
   3351 			 * is current
   3352 			 */
   3353 			if (!vector_page_p && l2pte_valid_p(npte)) {
   3354 				/*
   3355 				 * This mapping is likely to be accessed as
   3356 				 * soon as we return to userland. Fix up the
   3357 				 * L1 entry to avoid taking another
   3358 				 * page/domain fault.
   3359 				 */
   3360 				pd_entry_t *pdep = pmap_l1_kva(pm)
   3361 				     + l1pte_index(va);
   3362 				pd_entry_t pde = L1_C_PROTO | l2b->l2b_pa
   3363 				    | L1_C_DOM(pmap_domain(pm));
   3364 				if (*pdep != pde) {
   3365 					l1pte_setone(pdep, pde);
   3366 					PDE_SYNC(pdep);
   3367 				}
   3368 			}
   3369 		}
   3370 #endif /* !ARM_MMU_EXTENDED */
   3371 
   3372 #ifndef ARM_MMU_EXTENDED
   3373 		UVMHIST_LOG(maphist, "  is_cached %d cs 0x%08x\n",
   3374 		    is_cached, pm->pm_cstate.cs_all, 0, 0);
   3375 
   3376 		if (pg != NULL) {
   3377 			struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   3378 
   3379 			pmap_acquire_page_lock(md);
   3380 			pmap_vac_me_harder(md, pa, pm, va);
   3381 			pmap_release_page_lock(md);
   3382 		}
   3383 #endif
   3384 	}
   3385 #if defined(PMAP_CACHE_VIPT) && defined(DIAGNOSTIC)
   3386 	if (pg) {
   3387 		struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   3388 
   3389 		pmap_acquire_page_lock(md);
   3390 #ifndef ARM_MMU_EXTENDED
   3391 		KASSERT((md->pvh_attrs & PVF_DMOD) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   3392 #endif
   3393 		PMAP_VALIDATE_MD_PAGE(md);
   3394 		pmap_release_page_lock(md);
   3395 	}
   3396 #endif
   3397 
   3398 	pmap_release_pmap_lock(pm);
   3399 
   3400 	return (0);
   3401 }
   3402 
   3403 /*
   3404  * pmap_remove()
   3405  *
   3406  * pmap_remove is responsible for nuking a number of mappings for a range
   3407  * of virtual address space in the current pmap. To do this efficiently
   3408  * is interesting, because in a number of cases a wide virtual address
   3409  * range may be supplied that contains few actual mappings. So, the
   3410  * optimisations are:
   3411  *  1. Skip over hunks of address space for which no L1 or L2 entry exists.
   3412  *  2. Build up a list of pages we've hit, up to a maximum, so we can
   3413  *     maybe do just a partial cache clean. This path of execution is
   3414  *     complicated by the fact that the cache must be flushed _before_
   3415  *     the PTE is nuked, being a VAC :-)
   3416  *  3. If we're called after UVM calls pmap_remove_all(), we can defer
   3417  *     all invalidations until pmap_update(), since pmap_remove_all() has
   3418  *     already flushed the cache.
   3419  *  4. Maybe later fast-case a single page, but I don't think this is
   3420  *     going to make _that_ much difference overall.
   3421  */
   3422 
   3423 #define	PMAP_REMOVE_CLEAN_LIST_SIZE	3
   3424 
   3425 void
   3426 pmap_remove(pmap_t pm, vaddr_t sva, vaddr_t eva)
   3427 {
   3428 	vaddr_t next_bucket;
   3429 	u_int cleanlist_idx, total, cnt;
   3430 	struct {
   3431 		vaddr_t va;
   3432 		pt_entry_t *ptep;
   3433 	} cleanlist[PMAP_REMOVE_CLEAN_LIST_SIZE];
   3434 	u_int mappings;
   3435 
   3436 	UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
   3437 	UVMHIST_LOG(maphist, " (pm=%p, sva=%#x, eva=%#x)", pm, sva, eva, 0);
   3438 
   3439 	/*
   3440 	 * we lock in the pmap => pv_head direction
   3441 	 */
   3442 	pmap_acquire_pmap_lock(pm);
   3443 
   3444 	if (pm->pm_remove_all || !pmap_is_cached(pm)) {
   3445 		cleanlist_idx = PMAP_REMOVE_CLEAN_LIST_SIZE + 1;
   3446 #ifndef ARM_MMU_EXTENDED
   3447 		if (pm->pm_cstate.cs_tlb == 0)
   3448 			pm->pm_remove_all = true;
   3449 #endif
   3450 	} else
   3451 		cleanlist_idx = 0;
   3452 
   3453 	total = 0;
   3454 
   3455 	while (sva < eva) {
   3456 		/*
   3457 		 * Do one L2 bucket's worth at a time.
   3458 		 */
   3459 		next_bucket = L2_NEXT_BUCKET_VA(sva);
   3460 		if (next_bucket > eva)
   3461 			next_bucket = eva;
   3462 
   3463 		struct l2_bucket * const l2b = pmap_get_l2_bucket(pm, sva);
   3464 		if (l2b == NULL) {
   3465 			sva = next_bucket;
   3466 			continue;
   3467 		}
   3468 
   3469 		pt_entry_t *ptep = &l2b->l2b_kva[l2pte_index(sva)];
   3470 
   3471 		for (mappings = 0;
   3472 		     sva < next_bucket;
   3473 		     sva += PAGE_SIZE, ptep += PAGE_SIZE / L2_S_SIZE) {
   3474 			pt_entry_t opte = *ptep;
   3475 
   3476 			if (opte == 0) {
   3477 				/* Nothing here, move along */
   3478 				continue;
   3479 			}
   3480 
   3481 			u_int flags = PVF_REF;
   3482 			paddr_t pa = l2pte_pa(opte);
   3483 			struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
   3484 
   3485 			/*
   3486 			 * Update flags. In a number of circumstances,
   3487 			 * we could cluster a lot of these and do a
   3488 			 * number of sequential pages in one go.
   3489 			 */
   3490 			if (pg != NULL) {
   3491 				struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   3492 				struct pv_entry *pv;
   3493 
   3494 				pmap_acquire_page_lock(md);
   3495 				pv = pmap_remove_pv(md, pa, pm, sva);
   3496 				pmap_vac_me_harder(md, pa, pm, 0);
   3497 				pmap_release_page_lock(md);
   3498 				if (pv != NULL) {
   3499 					if (pm->pm_remove_all == false) {
   3500 						flags = pv->pv_flags;
   3501 					}
   3502 					pool_put(&pmap_pv_pool, pv);
   3503 				}
   3504 			}
   3505 			mappings += PAGE_SIZE / L2_S_SIZE;
   3506 
   3507 			if (!l2pte_valid_p(opte)) {
   3508 				/*
   3509 				 * Ref/Mod emulation is still active for this
   3510 				 * mapping, therefore it is has not yet been
   3511 				 * accessed. No need to frob the cache/tlb.
   3512 				 */
   3513 				l2pte_reset(ptep);
   3514 				PTE_SYNC_CURRENT(pm, ptep);
   3515 				continue;
   3516 			}
   3517 
   3518 #ifdef ARM_MMU_EXTENDED
   3519 			if (pm == pmap_kernel()) {
   3520 				l2pte_reset(ptep);
   3521 				PTE_SYNC(ptep);
   3522  				pmap_tlb_flush_SE(pm, sva, flags);
   3523 				continue;
   3524 			}
   3525 #endif
   3526 			if (cleanlist_idx < PMAP_REMOVE_CLEAN_LIST_SIZE) {
   3527 				/* Add to the clean list. */
   3528 				cleanlist[cleanlist_idx].ptep = ptep;
   3529 				cleanlist[cleanlist_idx].va =
   3530 				    sva | (flags & PVF_EXEC);
   3531 				cleanlist_idx++;
   3532 			} else if (cleanlist_idx == PMAP_REMOVE_CLEAN_LIST_SIZE) {
   3533 				/* Nuke everything if needed. */
   3534 #ifdef PMAP_CACHE_VIVT
   3535 				pmap_cache_wbinv_all(pm, PVF_EXEC);
   3536 #endif
   3537 				/*
   3538 				 * Roll back the previous PTE list,
   3539 				 * and zero out the current PTE.
   3540 				 */
   3541 				for (cnt = 0;
   3542 				     cnt < PMAP_REMOVE_CLEAN_LIST_SIZE; cnt++) {
   3543 					l2pte_reset(cleanlist[cnt].ptep);
   3544 					PTE_SYNC(cleanlist[cnt].ptep);
   3545 				}
   3546 				l2pte_reset(ptep);
   3547 				PTE_SYNC(ptep);
   3548 				cleanlist_idx++;
   3549 				pm->pm_remove_all = true;
   3550 			} else {
   3551 				l2pte_reset(ptep);
   3552 				PTE_SYNC(ptep);
   3553 				if (pm->pm_remove_all == false) {
   3554 					pmap_tlb_flush_SE(pm, sva, flags);
   3555 				}
   3556 			}
   3557 		}
   3558 
   3559 		/*
   3560 		 * Deal with any left overs
   3561 		 */
   3562 		if (cleanlist_idx <= PMAP_REMOVE_CLEAN_LIST_SIZE) {
   3563 			total += cleanlist_idx;
   3564 			for (cnt = 0; cnt < cleanlist_idx; cnt++) {
   3565 				l2pte_reset(cleanlist[cnt].ptep);
   3566 				PTE_SYNC_CURRENT(pm, cleanlist[cnt].ptep);
   3567 #ifdef ARM_MMU_EXTENDED
   3568 				vaddr_t clva = cleanlist[cnt].va;
   3569 				pmap_tlb_flush_SE(pm, clva, PVF_REF);
   3570 #else
   3571 				vaddr_t va = cleanlist[cnt].va;
   3572 				if (pm->pm_cstate.cs_all != 0) {
   3573 					vaddr_t clva = va & ~PAGE_MASK;
   3574 					u_int flags = va & PVF_EXEC;
   3575 #ifdef PMAP_CACHE_VIVT
   3576 					pmap_cache_wbinv_page(pm, clva, true,
   3577 					    PVF_REF | PVF_WRITE | flags);
   3578 #endif
   3579 					pmap_tlb_flush_SE(pm, clva,
   3580 					    PVF_REF | flags);
   3581 				}
   3582 #endif /* ARM_MMU_EXTENDED */
   3583 			}
   3584 
   3585 			/*
   3586 			 * If it looks like we're removing a whole bunch
   3587 			 * of mappings, it's faster to just write-back
   3588 			 * the whole cache now and defer TLB flushes until
   3589 			 * pmap_update() is called.
   3590 			 */
   3591 			if (total <= PMAP_REMOVE_CLEAN_LIST_SIZE)
   3592 				cleanlist_idx = 0;
   3593 			else {
   3594 				cleanlist_idx = PMAP_REMOVE_CLEAN_LIST_SIZE + 1;
   3595 #ifdef PMAP_CACHE_VIVT
   3596 				pmap_cache_wbinv_all(pm, PVF_EXEC);
   3597 #endif
   3598 				pm->pm_remove_all = true;
   3599 			}
   3600 		}
   3601 
   3602 
   3603 		pmap_free_l2_bucket(pm, l2b, mappings);
   3604 		pm->pm_stats.resident_count -= mappings / (PAGE_SIZE/L2_S_SIZE);
   3605 	}
   3606 
   3607 	pmap_release_pmap_lock(pm);
   3608 }
   3609 
   3610 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   3611 static struct pv_entry *
   3612 pmap_kremove_pg(struct vm_page *pg, vaddr_t va)
   3613 {
   3614 	struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   3615 	paddr_t pa = VM_PAGE_TO_PHYS(pg);
   3616 	struct pv_entry *pv;
   3617 
   3618 	KASSERT(arm_cache_prefer_mask == 0 || md->pvh_attrs & (PVF_COLORED|PVF_NC));
   3619 	KASSERT((md->pvh_attrs & PVF_KMPAGE) == 0);
   3620 	KASSERT(pmap_page_locked_p(md));
   3621 
   3622 	pv = pmap_remove_pv(md, pa, pmap_kernel(), va);
   3623 	KASSERTMSG(pv, "pg %p (pa #%lx) va %#lx", pg, pa, va);
   3624 	KASSERT(PV_IS_KENTRY_P(pv->pv_flags));
   3625 
   3626 	/*
   3627 	 * If we are removing a writeable mapping to a cached exec page,
   3628 	 * if it's the last mapping then clear it execness other sync
   3629 	 * the page to the icache.
   3630 	 */
   3631 	if ((md->pvh_attrs & (PVF_NC|PVF_EXEC)) == PVF_EXEC
   3632 	    && (pv->pv_flags & PVF_WRITE) != 0) {
   3633 		if (SLIST_EMPTY(&md->pvh_list)) {
   3634 			md->pvh_attrs &= ~PVF_EXEC;
   3635 			PMAPCOUNT(exec_discarded_kremove);
   3636 		} else {
   3637 			pmap_syncicache_page(md, pa);
   3638 			PMAPCOUNT(exec_synced_kremove);
   3639 		}
   3640 	}
   3641 	pmap_vac_me_harder(md, pa, pmap_kernel(), 0);
   3642 
   3643 	return pv;
   3644 }
   3645 #endif /* PMAP_CACHE_VIPT && !ARM_MMU_EXTENDED */
   3646 
   3647 /*
   3648  * pmap_kenter_pa: enter an unmanaged, wired kernel mapping
   3649  *
   3650  * We assume there is already sufficient KVM space available
   3651  * to do this, as we can't allocate L2 descriptor tables/metadata
   3652  * from here.
   3653  */
   3654 void
   3655 pmap_kenter_pa(vaddr_t va, paddr_t pa, vm_prot_t prot, u_int flags)
   3656 {
   3657 #ifdef PMAP_CACHE_VIVT
   3658 	struct vm_page *pg = (flags & PMAP_KMPAGE) ? PHYS_TO_VM_PAGE(pa) : NULL;
   3659 #endif
   3660 #ifdef PMAP_CACHE_VIPT
   3661 	struct vm_page *pg = PHYS_TO_VM_PAGE(pa);
   3662 	struct vm_page *opg;
   3663 #ifndef ARM_MMU_EXTENDED
   3664 	struct pv_entry *pv = NULL;
   3665 #endif
   3666 #endif
   3667 	struct vm_page_md *md = pg != NULL ? VM_PAGE_TO_MD(pg) : NULL;
   3668 
   3669 	UVMHIST_FUNC(__func__);
   3670 
   3671 	if (pmap_initialized) {
   3672 		UVMHIST_CALLED(maphist);
   3673 		UVMHIST_LOG(maphist, " (va=%#x, pa=%#x, prot=%#x, flags=%#x",
   3674 		    va, pa, prot, flags);
   3675 	}
   3676 
   3677 	pmap_t kpm = pmap_kernel();
   3678 	pmap_acquire_pmap_lock(kpm);
   3679 	struct l2_bucket * const l2b = pmap_get_l2_bucket(kpm, va);
   3680 	const size_t l1slot __diagused = l1pte_index(va);
   3681 	KASSERTMSG(l2b != NULL,
   3682 	    "va %#lx pa %#lx prot %d maxkvaddr %#lx: l2 %p l2b %p kva %p",
   3683 	    va, pa, prot, pmap_curmaxkvaddr, kpm->pm_l2[L2_IDX(l1slot)],
   3684 	    kpm->pm_l2[L2_IDX(l1slot)]
   3685 		? &kpm->pm_l2[L2_IDX(l1slot)]->l2_bucket[L2_BUCKET(l1slot)]
   3686 		: NULL,
   3687 	    kpm->pm_l2[L2_IDX(l1slot)]
   3688 		? kpm->pm_l2[L2_IDX(l1slot)]->l2_bucket[L2_BUCKET(l1slot)].l2b_kva
   3689 		: NULL);
   3690 	KASSERT(l2b->l2b_kva != NULL);
   3691 
   3692 	pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
   3693 	const pt_entry_t opte = *ptep;
   3694 
   3695 	if (opte == 0) {
   3696 		PMAPCOUNT(kenter_mappings);
   3697 		l2b->l2b_occupancy += PAGE_SIZE / L2_S_SIZE;
   3698 	} else {
   3699 		PMAPCOUNT(kenter_remappings);
   3700 #ifdef PMAP_CACHE_VIPT
   3701 		opg = PHYS_TO_VM_PAGE(l2pte_pa(opte));
   3702 #if !defined(ARM_MMU_EXTENDED) || defined(DIAGNOSTIC)
   3703 		struct vm_page_md *omd __diagused = VM_PAGE_TO_MD(opg);
   3704 #endif
   3705 		if (opg && arm_cache_prefer_mask != 0) {
   3706 			KASSERT(opg != pg);
   3707 			KASSERT((omd->pvh_attrs & PVF_KMPAGE) == 0);
   3708 			KASSERT((flags & PMAP_KMPAGE) == 0);
   3709 #ifndef ARM_MMU_EXTENDED
   3710 			pmap_acquire_page_lock(omd);
   3711 			pv = pmap_kremove_pg(opg, va);
   3712 			pmap_release_page_lock(omd);
   3713 #endif
   3714 		}
   3715 #endif
   3716 		if (l2pte_valid_p(opte)) {
   3717 			l2pte_reset(ptep);
   3718 			PTE_SYNC(ptep);
   3719 #ifdef PMAP_CACHE_VIVT
   3720 			cpu_dcache_wbinv_range(va, PAGE_SIZE);
   3721 #endif
   3722 			cpu_tlb_flushD_SE(va);
   3723 			cpu_cpwait();
   3724 		}
   3725 	}
   3726 	pmap_release_pmap_lock(kpm);
   3727 
   3728 	pt_entry_t npte = L2_S_PROTO | pa | L2_S_PROT(PTE_KERNEL, prot)
   3729 	    | ((flags & PMAP_NOCACHE)
   3730 		? 0
   3731 		: ((flags & PMAP_PTE)
   3732 		    ? pte_l2_s_cache_mode_pt : pte_l2_s_cache_mode));
   3733 #ifdef ARM_MMU_EXTENDED
   3734 	if (prot & VM_PROT_EXECUTE)
   3735 		npte &= ~L2_XS_XN;
   3736 #endif
   3737 	l2pte_set(ptep, npte, 0);
   3738 	PTE_SYNC(ptep);
   3739 
   3740 	if (pg) {
   3741 		if (flags & PMAP_KMPAGE) {
   3742 			KASSERT(md->urw_mappings == 0);
   3743 			KASSERT(md->uro_mappings == 0);
   3744 			KASSERT(md->krw_mappings == 0);
   3745 			KASSERT(md->kro_mappings == 0);
   3746 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   3747 			KASSERT(pv == NULL);
   3748 			KASSERT(arm_cache_prefer_mask == 0 || (va & PVF_COLORED) == 0);
   3749 			KASSERT((md->pvh_attrs & PVF_NC) == 0);
   3750 			/* if there is a color conflict, evict from cache. */
   3751 			if (pmap_is_page_colored_p(md)
   3752 			    && ((va ^ md->pvh_attrs) & arm_cache_prefer_mask)) {
   3753 				PMAPCOUNT(vac_color_change);
   3754 				pmap_flush_page(md, pa, PMAP_FLUSH_PRIMARY);
   3755 			} else if (md->pvh_attrs & PVF_MULTCLR) {
   3756 				/*
   3757 				 * If this page has multiple colors, expunge
   3758 				 * them.
   3759 				 */
   3760 				PMAPCOUNT(vac_flush_lots2);
   3761 				pmap_flush_page(md, pa, PMAP_FLUSH_SECONDARY);
   3762 			}
   3763 			/*
   3764 			 * Since this is a KMPAGE, there can be no contention
   3765 			 * for this page so don't lock it.
   3766 			 */
   3767 			md->pvh_attrs &= PAGE_SIZE - 1;
   3768 			md->pvh_attrs |= PVF_KMPAGE | PVF_COLORED | PVF_DIRTY
   3769 			    | (va & arm_cache_prefer_mask);
   3770 #else /* !PMAP_CACHE_VIPT || ARM_MMU_EXTENDED */
   3771 			md->pvh_attrs |= PVF_KMPAGE;
   3772 #endif
   3773 			atomic_inc_32(&pmap_kmpages);
   3774 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   3775 		} else if (arm_cache_prefer_mask != 0) {
   3776 			if (pv == NULL) {
   3777 				pv = pool_get(&pmap_pv_pool, PR_NOWAIT);
   3778 				KASSERT(pv != NULL);
   3779 			}
   3780 			pmap_acquire_page_lock(md);
   3781 			pmap_enter_pv(md, pa, pv, pmap_kernel(), va,
   3782 			    PVF_WIRED | PVF_KENTRY
   3783 			    | (prot & VM_PROT_WRITE ? PVF_WRITE : 0));
   3784 			if ((prot & VM_PROT_WRITE)
   3785 			    && !(md->pvh_attrs & PVF_NC))
   3786 				md->pvh_attrs |= PVF_DIRTY;
   3787 			KASSERT((prot & VM_PROT_WRITE) == 0 || (md->pvh_attrs & (PVF_DIRTY|PVF_NC)));
   3788 			pmap_vac_me_harder(md, pa, pmap_kernel(), va);
   3789 			pmap_release_page_lock(md);
   3790 #endif
   3791 		}
   3792 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   3793 	} else {
   3794 		if (pv != NULL)
   3795 			pool_put(&pmap_pv_pool, pv);
   3796 #endif
   3797 	}
   3798 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   3799 	KASSERT(md == NULL || !pmap_page_locked_p(md));
   3800 #endif
   3801 	if (pmap_initialized) {
   3802 		UVMHIST_LOG(maphist, "  <-- done (ptep %p: %#x -> %#x)",
   3803 		    ptep, opte, npte, 0);
   3804 	}
   3805 
   3806 }
   3807 
   3808 void
   3809 pmap_kremove(vaddr_t va, vsize_t len)
   3810 {
   3811 #ifdef UVMHIST
   3812 	u_int total_mappings = 0;
   3813 #endif
   3814 
   3815 	PMAPCOUNT(kenter_unmappings);
   3816 
   3817 	UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
   3818 
   3819 	UVMHIST_LOG(maphist, " (va=%#x, len=%#x)", va, len, 0, 0);
   3820 
   3821 	const vaddr_t eva = va + len;
   3822 
   3823 	pmap_acquire_pmap_lock(pmap_kernel());
   3824 
   3825 	while (va < eva) {
   3826 		vaddr_t next_bucket = L2_NEXT_BUCKET_VA(va);
   3827 		if (next_bucket > eva)
   3828 			next_bucket = eva;
   3829 
   3830 		pmap_t kpm = pmap_kernel();
   3831 		struct l2_bucket * const l2b = pmap_get_l2_bucket(kpm, va);
   3832 		KDASSERT(l2b != NULL);
   3833 
   3834 		pt_entry_t * const sptep = &l2b->l2b_kva[l2pte_index(va)];
   3835 		pt_entry_t *ptep = sptep;
   3836 		u_int mappings = 0;
   3837 
   3838 		while (va < next_bucket) {
   3839 			const pt_entry_t opte = *ptep;
   3840 			struct vm_page *opg = PHYS_TO_VM_PAGE(l2pte_pa(opte));
   3841 			if (opg != NULL) {
   3842 				struct vm_page_md *omd = VM_PAGE_TO_MD(opg);
   3843 
   3844 				if (omd->pvh_attrs & PVF_KMPAGE) {
   3845 					KASSERT(omd->urw_mappings == 0);
   3846 					KASSERT(omd->uro_mappings == 0);
   3847 					KASSERT(omd->krw_mappings == 0);
   3848 					KASSERT(omd->kro_mappings == 0);
   3849 					omd->pvh_attrs &= ~PVF_KMPAGE;
   3850 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   3851 					if (arm_cache_prefer_mask != 0) {
   3852 						omd->pvh_attrs &= ~PVF_WRITE;
   3853 					}
   3854 #endif
   3855 					atomic_dec_32(&pmap_kmpages);
   3856 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   3857 				} else if (arm_cache_prefer_mask != 0) {
   3858 					pmap_acquire_page_lock(omd);
   3859 					pool_put(&pmap_pv_pool,
   3860 					    pmap_kremove_pg(opg, va));
   3861 					pmap_release_page_lock(omd);
   3862 #endif
   3863 				}
   3864 			}
   3865 			if (l2pte_valid_p(opte)) {
   3866 				l2pte_reset(ptep);
   3867 				PTE_SYNC(ptep);
   3868 #ifdef PMAP_CACHE_VIVT
   3869 				cpu_dcache_wbinv_range(va, PAGE_SIZE);
   3870 #endif
   3871 				cpu_tlb_flushD_SE(va);
   3872 
   3873 				mappings += PAGE_SIZE / L2_S_SIZE;
   3874 			}
   3875 			va += PAGE_SIZE;
   3876 			ptep += PAGE_SIZE / L2_S_SIZE;
   3877 		}
   3878 		KDASSERTMSG(mappings <= l2b->l2b_occupancy, "%u %u",
   3879 		    mappings, l2b->l2b_occupancy);
   3880 		l2b->l2b_occupancy -= mappings;
   3881 		//PTE_SYNC_RANGE(sptep, (u_int)(ptep - sptep));
   3882 #ifdef UVMHIST
   3883 		total_mappings += mappings;
   3884 #endif
   3885 	}
   3886 	pmap_release_pmap_lock(pmap_kernel());
   3887 	cpu_cpwait();
   3888 	UVMHIST_LOG(maphist, "  <--- done (%u mappings removed)",
   3889 	    total_mappings, 0, 0, 0);
   3890 }
   3891 
   3892 bool
   3893 pmap_extract(pmap_t pm, vaddr_t va, paddr_t *pap)
   3894 {
   3895 	struct l2_dtable *l2;
   3896 	pd_entry_t *pdep, pde;
   3897 	pt_entry_t *ptep, pte;
   3898 	paddr_t pa;
   3899 	u_int l1slot;
   3900 
   3901 	pmap_acquire_pmap_lock(pm);
   3902 
   3903 	l1slot = l1pte_index(va);
   3904 	pdep = pmap_l1_kva(pm) + l1slot;
   3905 	pde = *pdep;
   3906 
   3907 	if (l1pte_section_p(pde)) {
   3908 		/*
   3909 		 * These should only happen for pmap_kernel()
   3910 		 */
   3911 		KDASSERT(pm == pmap_kernel());
   3912 		pmap_release_pmap_lock(pm);
   3913 #if (ARM_MMU_V6 + ARM_MMU_V7) > 0
   3914 		if (l1pte_supersection_p(pde)) {
   3915 			pa = (pde & L1_SS_FRAME) | (va & L1_SS_OFFSET);
   3916 		} else
   3917 #endif
   3918 			pa = (pde & L1_S_FRAME) | (va & L1_S_OFFSET);
   3919 	} else {
   3920 		/*
   3921 		 * Note that we can't rely on the validity of the L1
   3922 		 * descriptor as an indication that a mapping exists.
   3923 		 * We have to look it up in the L2 dtable.
   3924 		 */
   3925 		l2 = pm->pm_l2[L2_IDX(l1slot)];
   3926 
   3927 		if (l2 == NULL ||
   3928 		    (ptep = l2->l2_bucket[L2_BUCKET(l1slot)].l2b_kva) == NULL) {
   3929 			pmap_release_pmap_lock(pm);
   3930 			return false;
   3931 		}
   3932 
   3933 		pte = ptep[l2pte_index(va)];
   3934 		pmap_release_pmap_lock(pm);
   3935 
   3936 		if (pte == 0)
   3937 			return false;
   3938 
   3939 		switch (pte & L2_TYPE_MASK) {
   3940 		case L2_TYPE_L:
   3941 			pa = (pte & L2_L_FRAME) | (va & L2_L_OFFSET);
   3942 			break;
   3943 
   3944 		default:
   3945 			pa = (pte & ~PAGE_MASK) | (va & PAGE_MASK);
   3946 			break;
   3947 		}
   3948 	}
   3949 
   3950 	if (pap != NULL)
   3951 		*pap = pa;
   3952 
   3953 	return true;
   3954 }
   3955 
   3956 /*
   3957  * pmap_pv_remove: remove an unmanaged pv-tracked page from all pmaps
   3958  *	that map it
   3959  */
   3960 
   3961 static void
   3962 pmap_pv_remove(paddr_t pa)
   3963 {
   3964 	struct pmap_page *pp;
   3965 
   3966 	pp = pmap_pv_tracked(pa);
   3967 	if (pp == NULL)
   3968 		panic("pmap_pv_protect: page not pv-tracked: 0x%"PRIxPADDR,
   3969 		    pa);
   3970 
   3971 	struct vm_page_md *md = PMAP_PAGE_TO_MD(pp);
   3972 	pmap_page_remove(md, pa);
   3973 }
   3974 
   3975 void
   3976 pmap_pv_protect(paddr_t pa, vm_prot_t prot)
   3977 {
   3978 
   3979 	/* the only case is remove at the moment */
   3980 	KASSERT(prot == VM_PROT_NONE);
   3981 	pmap_pv_remove(pa);
   3982 }
   3983 
   3984 void
   3985 pmap_protect(pmap_t pm, vaddr_t sva, vaddr_t eva, vm_prot_t prot)
   3986 {
   3987 	struct l2_bucket *l2b;
   3988 	vaddr_t next_bucket;
   3989 
   3990 	NPDEBUG(PDB_PROTECT,
   3991 	    printf("pmap_protect: pm %p sva 0x%lx eva 0x%lx prot 0x%x\n",
   3992 	    pm, sva, eva, prot));
   3993 
   3994 	if ((prot & VM_PROT_READ) == 0) {
   3995 		pmap_remove(pm, sva, eva);
   3996 		return;
   3997 	}
   3998 
   3999 	if (prot & VM_PROT_WRITE) {
   4000 		/*
   4001 		 * If this is a read->write transition, just ignore it and let
   4002 		 * uvm_fault() take care of it later.
   4003 		 */
   4004 		return;
   4005 	}
   4006 
   4007 	pmap_acquire_pmap_lock(pm);
   4008 
   4009 #ifndef ARM_MMU_EXTENDED
   4010 	const bool flush = eva - sva >= PAGE_SIZE * 4;
   4011 	u_int flags = 0;
   4012 #endif
   4013 	u_int clr_mask = PVF_WRITE | ((prot & VM_PROT_EXECUTE) ? 0 : PVF_EXEC);
   4014 
   4015 	while (sva < eva) {
   4016 		next_bucket = L2_NEXT_BUCKET_VA(sva);
   4017 		if (next_bucket > eva)
   4018 			next_bucket = eva;
   4019 
   4020 		l2b = pmap_get_l2_bucket(pm, sva);
   4021 		if (l2b == NULL) {
   4022 			sva = next_bucket;
   4023 			continue;
   4024 		}
   4025 
   4026 		pt_entry_t *ptep = &l2b->l2b_kva[l2pte_index(sva)];
   4027 
   4028 		while (sva < next_bucket) {
   4029 			const pt_entry_t opte = *ptep;
   4030 			if (l2pte_valid_p(opte) && l2pte_writable_p(opte)) {
   4031 				struct vm_page *pg;
   4032 #ifndef ARM_MMU_EXTENDED
   4033 				u_int f;
   4034 #endif
   4035 
   4036 #ifdef PMAP_CACHE_VIVT
   4037 				/*
   4038 				 * OK, at this point, we know we're doing
   4039 				 * write-protect operation.  If the pmap is
   4040 				 * active, write-back the page.
   4041 				 */
   4042 				pmap_cache_wbinv_page(pm, sva, false,
   4043 				    PVF_REF | PVF_WRITE);
   4044 #endif
   4045 
   4046 				pg = PHYS_TO_VM_PAGE(l2pte_pa(opte));
   4047 				pt_entry_t npte = l2pte_set_readonly(opte);
   4048 				l2pte_reset(ptep);
   4049 				PTE_SYNC(ptep);
   4050 #ifdef ARM_MMU_EXTENDED
   4051 				pmap_tlb_flush_SE(pm, sva, PVF_REF);
   4052 #endif
   4053 				l2pte_set(ptep, npte, 0);
   4054 				PTE_SYNC(ptep);
   4055 
   4056 				if (pg != NULL) {
   4057 					struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   4058 					paddr_t pa = VM_PAGE_TO_PHYS(pg);
   4059 
   4060 					pmap_acquire_page_lock(md);
   4061 #ifndef ARM_MMU_EXTENDED
   4062 					f =
   4063 #endif
   4064 					    pmap_modify_pv(md, pa, pm, sva,
   4065 					       clr_mask, 0);
   4066 					pmap_vac_me_harder(md, pa, pm, sva);
   4067 					pmap_release_page_lock(md);
   4068 #ifndef ARM_MMU_EXTENDED
   4069 				} else {
   4070 					f = PVF_REF | PVF_EXEC;
   4071 				}
   4072 
   4073 				if (flush) {
   4074 					flags |= f;
   4075 				} else {
   4076 					pmap_tlb_flush_SE(pm, sva, f);
   4077 #endif
   4078 				}
   4079 			}
   4080 
   4081 			sva += PAGE_SIZE;
   4082 			ptep += PAGE_SIZE / L2_S_SIZE;
   4083 		}
   4084 	}
   4085 
   4086 #ifndef ARM_MMU_EXTENDED
   4087 	if (flush) {
   4088 		if (PV_BEEN_EXECD(flags)) {
   4089 			pmap_tlb_flushID(pm);
   4090 		} else if (PV_BEEN_REFD(flags)) {
   4091 			pmap_tlb_flushD(pm);
   4092 		}
   4093 	}
   4094 #endif
   4095 
   4096 	pmap_release_pmap_lock(pm);
   4097 }
   4098 
   4099 void
   4100 pmap_icache_sync_range(pmap_t pm, vaddr_t sva, vaddr_t eva)
   4101 {
   4102 	struct l2_bucket *l2b;
   4103 	pt_entry_t *ptep;
   4104 	vaddr_t next_bucket;
   4105 	vsize_t page_size = trunc_page(sva) + PAGE_SIZE - sva;
   4106 
   4107 	NPDEBUG(PDB_EXEC,
   4108 	    printf("pmap_icache_sync_range: pm %p sva 0x%lx eva 0x%lx\n",
   4109 	    pm, sva, eva));
   4110 
   4111 	pmap_acquire_pmap_lock(pm);
   4112 
   4113 	while (sva < eva) {
   4114 		next_bucket = L2_NEXT_BUCKET_VA(sva);
   4115 		if (next_bucket > eva)
   4116 			next_bucket = eva;
   4117 
   4118 		l2b = pmap_get_l2_bucket(pm, sva);
   4119 		if (l2b == NULL) {
   4120 			sva = next_bucket;
   4121 			continue;
   4122 		}
   4123 
   4124 		for (ptep = &l2b->l2b_kva[l2pte_index(sva)];
   4125 		     sva < next_bucket;
   4126 		     sva += page_size,
   4127 		     ptep += PAGE_SIZE / L2_S_SIZE,
   4128 		     page_size = PAGE_SIZE) {
   4129 			if (l2pte_valid_p(*ptep)) {
   4130 				cpu_icache_sync_range(sva,
   4131 				    min(page_size, eva - sva));
   4132 			}
   4133 		}
   4134 	}
   4135 
   4136 	pmap_release_pmap_lock(pm);
   4137 }
   4138 
   4139 void
   4140 pmap_page_protect(struct vm_page *pg, vm_prot_t prot)
   4141 {
   4142 	struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   4143 	paddr_t pa = VM_PAGE_TO_PHYS(pg);
   4144 
   4145 	NPDEBUG(PDB_PROTECT,
   4146 	    printf("pmap_page_protect: md %p (0x%08lx), prot 0x%x\n",
   4147 	    md, pa, prot));
   4148 
   4149 	switch(prot) {
   4150 	case VM_PROT_READ|VM_PROT_WRITE:
   4151 #if defined(ARM_MMU_EXTENDED)
   4152 		pmap_acquire_page_lock(md);
   4153 		pmap_clearbit(md, pa, PVF_EXEC);
   4154 		pmap_release_page_lock(md);
   4155 		break;
   4156 #endif
   4157 	case VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE:
   4158 		break;
   4159 
   4160 	case VM_PROT_READ:
   4161 #if defined(ARM_MMU_EXTENDED)
   4162 		pmap_acquire_page_lock(md);
   4163 		pmap_clearbit(md, pa, PVF_WRITE|PVF_EXEC);
   4164 		pmap_release_page_lock(md);
   4165 		break;
   4166 #endif
   4167 	case VM_PROT_READ|VM_PROT_EXECUTE:
   4168 		pmap_acquire_page_lock(md);
   4169 		pmap_clearbit(md, pa, PVF_WRITE);
   4170 		pmap_release_page_lock(md);
   4171 		break;
   4172 
   4173 	default:
   4174 		pmap_page_remove(md, pa);
   4175 		break;
   4176 	}
   4177 }
   4178 
   4179 /*
   4180  * pmap_clear_modify:
   4181  *
   4182  *	Clear the "modified" attribute for a page.
   4183  */
   4184 bool
   4185 pmap_clear_modify(struct vm_page *pg)
   4186 {
   4187 	struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   4188 	paddr_t pa = VM_PAGE_TO_PHYS(pg);
   4189 	bool rv;
   4190 
   4191 	pmap_acquire_page_lock(md);
   4192 
   4193 	if (md->pvh_attrs & PVF_MOD) {
   4194 		rv = true;
   4195 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   4196 		/*
   4197 		 * If we are going to clear the modified bit and there are
   4198 		 * no other modified bits set, flush the page to memory and
   4199 		 * mark it clean.
   4200 		 */
   4201 		if ((md->pvh_attrs & (PVF_DMOD|PVF_NC)) == PVF_MOD)
   4202 			pmap_flush_page(md, pa, PMAP_CLEAN_PRIMARY);
   4203 #endif
   4204 		pmap_clearbit(md, pa, PVF_MOD);
   4205 	} else {
   4206 		rv = false;
   4207 	}
   4208 	pmap_release_page_lock(md);
   4209 
   4210 	return rv;
   4211 }
   4212 
   4213 /*
   4214  * pmap_clear_reference:
   4215  *
   4216  *	Clear the "referenced" attribute for a page.
   4217  */
   4218 bool
   4219 pmap_clear_reference(struct vm_page *pg)
   4220 {
   4221 	struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   4222 	paddr_t pa = VM_PAGE_TO_PHYS(pg);
   4223 	bool rv;
   4224 
   4225 	pmap_acquire_page_lock(md);
   4226 
   4227 	if (md->pvh_attrs & PVF_REF) {
   4228 		rv = true;
   4229 		pmap_clearbit(md, pa, PVF_REF);
   4230 	} else {
   4231 		rv = false;
   4232 	}
   4233 	pmap_release_page_lock(md);
   4234 
   4235 	return rv;
   4236 }
   4237 
   4238 /*
   4239  * pmap_is_modified:
   4240  *
   4241  *	Test if a page has the "modified" attribute.
   4242  */
   4243 /* See <arm/arm32/pmap.h> */
   4244 
   4245 /*
   4246  * pmap_is_referenced:
   4247  *
   4248  *	Test if a page has the "referenced" attribute.
   4249  */
   4250 /* See <arm/arm32/pmap.h> */
   4251 
   4252 #if defined(ARM_MMU_EXTENDED) && 0
   4253 int
   4254 pmap_prefetchabt_fixup(void *v)
   4255 {
   4256 	struct trapframe * const tf = v;
   4257 	vaddr_t va = trunc_page(tf->tf_pc);
   4258 	int rv = ABORT_FIXUP_FAILED;
   4259 
   4260 	if (!TRAP_USERMODE(tf) && va < VM_MAXUSER_ADDRESS)
   4261 		return rv;
   4262 
   4263 	kpreempt_disable();
   4264 	pmap_t pm = curcpu()->ci_pmap_cur;
   4265 	const size_t l1slot = l1pte_index(va);
   4266 	struct l2_dtable * const l2 = pm->pm_l2[L2_IDX(l1slot)];
   4267 	if (l2 == NULL)
   4268 		goto out;
   4269 
   4270 	struct l2_bucket * const l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];
   4271 	if (l2b->l2b_kva == NULL)
   4272 		goto out;
   4273 
   4274 	/*
   4275 	 * Check the PTE itself.
   4276 	 */
   4277 	pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
   4278 	const pt_entry_t opte = *ptep;
   4279 	if ((opte & L2_S_PROT_U) == 0 || (opte & L2_XS_XN) == 0)
   4280 		goto out;
   4281 
   4282 	paddr_t pa = l2pte_pa(pte);
   4283 	struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
   4284 	KASSERT(pg != NULL);
   4285 
   4286 	struct vm_page_md * const md = VM_PAGE_TO_MD(pg);
   4287 
   4288 	pmap_acquire_page_lock(md);
   4289 	struct pv_entry * const pv = pmap_find_pv(md, pm, va);
   4290 	KASSERT(pv != NULL);
   4291 
   4292 	if (PV_IS_EXEC_P(pv->pv_flags)) {
   4293 		l2pte_reset(ptep);
   4294 		PTE_SYNC(ptep);
   4295 		pmap_tlb_flush_SE(pm, va, PVF_EXEC | PVF_REF);
   4296 		if (!PV_IS_EXEC_P(md->pvh_attrs)) {
   4297 			pmap_syncicache_page(md, pa);
   4298 		}
   4299 		rv = ABORT_FIXUP_RETURN;
   4300 		l2pte_set(ptep, opte & ~L2_XS_XN, 0);
   4301 		PTE_SYNC(ptep);
   4302 	}
   4303 	pmap_release_page_lock(md);
   4304 
   4305   out:
   4306 	kpreempt_enable();
   4307 	return rv;
   4308 }
   4309 #endif
   4310 
   4311 int
   4312 pmap_fault_fixup(pmap_t pm, vaddr_t va, vm_prot_t ftype, int user)
   4313 {
   4314 	struct l2_dtable *l2;
   4315 	struct l2_bucket *l2b;
   4316 	paddr_t pa;
   4317 	const size_t l1slot = l1pte_index(va);
   4318 	int rv = 0;
   4319 
   4320 	UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
   4321 
   4322 	va = trunc_page(va);
   4323 
   4324 	KASSERT(!user || (pm != pmap_kernel()));
   4325 
   4326 	UVMHIST_LOG(maphist, " (pm=%#x, va=%#x, ftype=%#x, user=%d)",
   4327 	    pm, va, ftype, user);
   4328 #ifdef ARM_MMU_EXTENDED
   4329 	UVMHIST_LOG(maphist, " ti=%#x pai=%#x asid=%#x",
   4330 	    cpu_tlb_info(curcpu()), PMAP_PAI(pm, cpu_tlb_info(curcpu())),
   4331 	    PMAP_PAI(pm, cpu_tlb_info(curcpu()))->pai_asid, 0);
   4332 #endif
   4333 
   4334 	pmap_acquire_pmap_lock(pm);
   4335 
   4336 	/*
   4337 	 * If there is no l2_dtable for this address, then the process
   4338 	 * has no business accessing it.
   4339 	 *
   4340 	 * Note: This will catch userland processes trying to access
   4341 	 * kernel addresses.
   4342 	 */
   4343 	l2 = pm->pm_l2[L2_IDX(l1slot)];
   4344 	if (l2 == NULL) {
   4345 		UVMHIST_LOG(maphist, " no l2 for l1slot %#x", l1slot, 0, 0, 0);
   4346 		goto out;
   4347 	}
   4348 
   4349 	/*
   4350 	 * Likewise if there is no L2 descriptor table
   4351 	 */
   4352 	l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];
   4353 	if (l2b->l2b_kva == NULL) {
   4354 		UVMHIST_LOG(maphist, " <-- done (no ptep for l1slot %#x)", l1slot, 0, 0, 0);
   4355 		goto out;
   4356 	}
   4357 
   4358 	/*
   4359 	 * Check the PTE itself.
   4360 	 */
   4361 	pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
   4362 	pt_entry_t const opte = *ptep;
   4363 	if (opte == 0 || (opte & L2_TYPE_MASK) == L2_TYPE_L) {
   4364 		UVMHIST_LOG(maphist, " <-- done (empty pde for l1slot %#x)", l1slot, 0, 0, 0);
   4365 		goto out;
   4366 	}
   4367 
   4368 #ifndef ARM_HAS_VBAR
   4369 	/*
   4370 	 * Catch a userland access to the vector page mapped at 0x0
   4371 	 */
   4372 	if (user && (opte & L2_S_PROT_U) == 0) {
   4373 		UVMHIST_LOG(maphist, " <-- done (vector_page)", 0, 0, 0, 0);
   4374 		goto out;
   4375 	}
   4376 #endif
   4377 
   4378 	pa = l2pte_pa(opte);
   4379 
   4380 	if ((ftype & VM_PROT_WRITE) && !l2pte_writable_p(opte)) {
   4381 		/*
   4382 		 * This looks like a good candidate for "page modified"
   4383 		 * emulation...
   4384 		 */
   4385 		struct pv_entry *pv;
   4386 		struct vm_page *pg;
   4387 
   4388 		/* Extract the physical address of the page */
   4389 		if ((pg = PHYS_TO_VM_PAGE(pa)) == NULL) {
   4390 			UVMHIST_LOG(maphist, " <-- done (mod/ref unmanaged page)", 0, 0, 0, 0);
   4391 			goto out;
   4392 		}
   4393 
   4394 		struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   4395 
   4396 		/* Get the current flags for this page. */
   4397 		pmap_acquire_page_lock(md);
   4398 		pv = pmap_find_pv(md, pm, va);
   4399 		if (pv == NULL || PV_IS_KENTRY_P(pv->pv_flags)) {
   4400 			pmap_release_page_lock(md);
   4401 			UVMHIST_LOG(maphist, " <-- done (mod/ref emul: no PV)", 0, 0, 0, 0);
   4402 			goto out;
   4403 		}
   4404 
   4405 		/*
   4406 		 * Do the flags say this page is writable? If not then it
   4407 		 * is a genuine write fault. If yes then the write fault is
   4408 		 * our fault as we did not reflect the write access in the
   4409 		 * PTE. Now we know a write has occurred we can correct this
   4410 		 * and also set the modified bit
   4411 		 */
   4412 		if ((pv->pv_flags & PVF_WRITE) == 0) {
   4413 			pmap_release_page_lock(md);
   4414 			goto out;
   4415 		}
   4416 
   4417 		md->pvh_attrs |= PVF_REF | PVF_MOD;
   4418 		pv->pv_flags |= PVF_REF | PVF_MOD;
   4419 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   4420 		/*
   4421 		 * If there are cacheable mappings for this page, mark it dirty.
   4422 		 */
   4423 		if ((md->pvh_attrs & PVF_NC) == 0)
   4424 			md->pvh_attrs |= PVF_DIRTY;
   4425 #endif
   4426 #ifdef ARM_MMU_EXTENDED
   4427 		if (md->pvh_attrs & PVF_EXEC) {
   4428 			md->pvh_attrs &= ~PVF_EXEC;
   4429 			PMAPCOUNT(exec_discarded_modfixup);
   4430 		}
   4431 #endif
   4432 		pmap_release_page_lock(md);
   4433 
   4434 		/*
   4435 		 * Re-enable write permissions for the page.  No need to call
   4436 		 * pmap_vac_me_harder(), since this is just a
   4437 		 * modified-emulation fault, and the PVF_WRITE bit isn't
   4438 		 * changing. We've already set the cacheable bits based on
   4439 		 * the assumption that we can write to this page.
   4440 		 */
   4441 		const pt_entry_t npte =
   4442 		    l2pte_set_writable((opte & ~L2_TYPE_MASK) | L2_S_PROTO)
   4443 #ifdef ARM_MMU_EXTENDED
   4444 		    | (pm != pmap_kernel() ? L2_XS_nG : 0)
   4445 #endif
   4446 		    | 0;
   4447 		l2pte_reset(ptep);
   4448 		PTE_SYNC(ptep);
   4449 		pmap_tlb_flush_SE(pm, va,
   4450 		    (ftype & VM_PROT_EXECUTE) ? PVF_EXEC | PVF_REF : PVF_REF);
   4451 		l2pte_set(ptep, npte, 0);
   4452 		PTE_SYNC(ptep);
   4453 		PMAPCOUNT(fixup_mod);
   4454 		rv = 1;
   4455 		UVMHIST_LOG(maphist, " <-- done (mod/ref emul: changed pte from %#x to %#x)",
   4456 		    opte, npte, 0, 0);
   4457 	} else if ((opte & L2_TYPE_MASK) == L2_TYPE_INV) {
   4458 		/*
   4459 		 * This looks like a good candidate for "page referenced"
   4460 		 * emulation.
   4461 		 */
   4462 		struct vm_page *pg;
   4463 
   4464 		/* Extract the physical address of the page */
   4465 		if ((pg = PHYS_TO_VM_PAGE(pa)) == NULL) {
   4466 			UVMHIST_LOG(maphist, " <-- done (ref emul: unmanaged page)", 0, 0, 0, 0);
   4467 			goto out;
   4468 		}
   4469 
   4470 		struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   4471 
   4472 		/* Get the current flags for this page. */
   4473 		pmap_acquire_page_lock(md);
   4474 		struct pv_entry *pv = pmap_find_pv(md, pm, va);
   4475 		if (pv == NULL || PV_IS_KENTRY_P(pv->pv_flags)) {
   4476 			pmap_release_page_lock(md);
   4477 			UVMHIST_LOG(maphist, " <-- done (ref emul no PV)", 0, 0, 0, 0);
   4478 			goto out;
   4479 		}
   4480 
   4481 		md->pvh_attrs |= PVF_REF;
   4482 		pv->pv_flags |= PVF_REF;
   4483 
   4484 		pt_entry_t npte =
   4485 		    l2pte_set_readonly((opte & ~L2_TYPE_MASK) | L2_S_PROTO);
   4486 #ifdef ARM_MMU_EXTENDED
   4487 		if (pm != pmap_kernel()) {
   4488 			npte |= L2_XS_nG;
   4489 		}
   4490 		/*
   4491 		 * If we got called from prefetch abort, then ftype will have
   4492 		 * VM_PROT_EXECUTE set.  Now see if we have no-execute set in
   4493 		 * the PTE.
   4494 		 */
   4495 		if (user && (ftype & VM_PROT_EXECUTE) && (npte & L2_XS_XN)) {
   4496 			/*
   4497 			 * Is this a mapping of an executable page?
   4498 			 */
   4499 			if ((pv->pv_flags & PVF_EXEC) == 0) {
   4500 				pmap_release_page_lock(md);
   4501 				UVMHIST_LOG(maphist, " <-- done (ref emul: no exec)",
   4502 				    0, 0, 0, 0);
   4503 				goto out;
   4504 			}
   4505 			/*
   4506 			 * If we haven't synced the page, do so now.
   4507 			 */
   4508 			if ((md->pvh_attrs & PVF_EXEC) == 0) {
   4509 				UVMHIST_LOG(maphist, " ref emul: syncicache page #%#x",
   4510 				    pa, 0, 0, 0);
   4511 				pmap_syncicache_page(md, pa);
   4512 				PMAPCOUNT(fixup_exec);
   4513 			}
   4514 			npte &= ~L2_XS_XN;
   4515 		}
   4516 #endif /* ARM_MMU_EXTENDED */
   4517 		pmap_release_page_lock(md);
   4518 		l2pte_reset(ptep);
   4519 		PTE_SYNC(ptep);
   4520 		pmap_tlb_flush_SE(pm, va,
   4521 		    (ftype & VM_PROT_EXECUTE) ? PVF_EXEC | PVF_REF : PVF_REF);
   4522 		l2pte_set(ptep, npte, 0);
   4523 		PTE_SYNC(ptep);
   4524 		PMAPCOUNT(fixup_ref);
   4525 		rv = 1;
   4526 		UVMHIST_LOG(maphist, " <-- done (ref emul: changed pte from %#x to %#x)",
   4527 		    opte, npte, 0, 0);
   4528 #ifdef ARM_MMU_EXTENDED
   4529 	} else if (user && (ftype & VM_PROT_EXECUTE) && (opte & L2_XS_XN)) {
   4530 		struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
   4531 		if (pg == NULL) {
   4532 			UVMHIST_LOG(maphist, " <-- done (unmanaged page)", 0, 0, 0, 0);
   4533 			goto out;
   4534 		}
   4535 
   4536 		struct vm_page_md * const md = VM_PAGE_TO_MD(pg);
   4537 
   4538 		/* Get the current flags for this page. */
   4539 		pmap_acquire_page_lock(md);
   4540 		struct pv_entry * const pv = pmap_find_pv(md, pm, va);
   4541 		if (pv == NULL || (pv->pv_flags & PVF_EXEC) == 0) {
   4542 			pmap_release_page_lock(md);
   4543 			UVMHIST_LOG(maphist, " <-- done (no PV or not EXEC)", 0, 0, 0, 0);
   4544 			goto out;
   4545 		}
   4546 
   4547 		/*
   4548 		 * If we haven't synced the page, do so now.
   4549 		 */
   4550 		if ((md->pvh_attrs & PVF_EXEC) == 0) {
   4551 			UVMHIST_LOG(maphist, "syncicache page #%#x",
   4552 			    pa, 0, 0, 0);
   4553 			pmap_syncicache_page(md, pa);
   4554 		}
   4555 		pmap_release_page_lock(md);
   4556 		/*
   4557 		 * Turn off no-execute.
   4558 		 */
   4559 		KASSERT(opte & L2_XS_nG);
   4560 		l2pte_reset(ptep);
   4561 		PTE_SYNC(ptep);
   4562 		pmap_tlb_flush_SE(pm, va, PVF_EXEC | PVF_REF);
   4563 		l2pte_set(ptep, opte & ~L2_XS_XN, 0);
   4564 		PTE_SYNC(ptep);
   4565 		rv = 1;
   4566 		PMAPCOUNT(fixup_exec);
   4567 		UVMHIST_LOG(maphist, "exec: changed pte from %#x to %#x",
   4568 		    opte, opte & ~L2_XS_XN, 0, 0);
   4569 #endif
   4570 	}
   4571 
   4572 #ifndef ARM_MMU_EXTENDED
   4573 	/*
   4574 	 * We know there is a valid mapping here, so simply
   4575 	 * fix up the L1 if necessary.
   4576 	 */
   4577 	pd_entry_t * const pdep = pmap_l1_kva(pm) + l1slot;
   4578 	pd_entry_t pde = L1_C_PROTO | l2b->l2b_pa | L1_C_DOM(pmap_domain(pm));
   4579 	if (*pdep != pde) {
   4580 		l1pte_setone(pdep, pde);
   4581 		PDE_SYNC(pdep);
   4582 		rv = 1;
   4583 		PMAPCOUNT(fixup_pdes);
   4584 	}
   4585 #endif
   4586 
   4587 #ifdef CPU_SA110
   4588 	/*
   4589 	 * There are bugs in the rev K SA110.  This is a check for one
   4590 	 * of them.
   4591 	 */
   4592 	if (rv == 0 && curcpu()->ci_arm_cputype == CPU_ID_SA110 &&
   4593 	    curcpu()->ci_arm_cpurev < 3) {
   4594 		/* Always current pmap */
   4595 		if (l2pte_valid_p(opte)) {
   4596 			extern int kernel_debug;
   4597 			if (kernel_debug & 1) {
   4598 				struct proc *p = curlwp->l_proc;
   4599 				printf("prefetch_abort: page is already "
   4600 				    "mapped - pte=%p *pte=%08x\n", ptep, opte);
   4601 				printf("prefetch_abort: pc=%08lx proc=%p "
   4602 				    "process=%s\n", va, p, p->p_comm);
   4603 				printf("prefetch_abort: far=%08x fs=%x\n",
   4604 				    cpu_faultaddress(), cpu_faultstatus());
   4605 			}
   4606 #ifdef DDB
   4607 			if (kernel_debug & 2)
   4608 				Debugger();
   4609 #endif
   4610 			rv = 1;
   4611 		}
   4612 	}
   4613 #endif /* CPU_SA110 */
   4614 
   4615 #ifndef ARM_MMU_EXTENDED
   4616 	/*
   4617 	 * If 'rv == 0' at this point, it generally indicates that there is a
   4618 	 * stale TLB entry for the faulting address.  That might be due to a
   4619 	 * wrong setting of pmap_needs_pte_sync.  So set it and retry.
   4620 	 */
   4621 	if (rv == 0
   4622 	    && pm->pm_l1->l1_domain_use_count == 1
   4623 	    && pmap_needs_pte_sync == 0) {
   4624 		pmap_needs_pte_sync = 1;
   4625 		PTE_SYNC(ptep);
   4626 		PMAPCOUNT(fixup_ptesync);
   4627 		rv = 1;
   4628 	}
   4629 #endif
   4630 
   4631 #ifndef MULTIPROCESSOR
   4632 #if defined(DEBUG) || 1
   4633 	/*
   4634 	 * If 'rv == 0' at this point, it generally indicates that there is a
   4635 	 * stale TLB entry for the faulting address. This happens when two or
   4636 	 * more processes are sharing an L1. Since we don't flush the TLB on
   4637 	 * a context switch between such processes, we can take domain faults
   4638 	 * for mappings which exist at the same VA in both processes. EVEN IF
   4639 	 * WE'VE RECENTLY FIXED UP THE CORRESPONDING L1 in pmap_enter(), for
   4640 	 * example.
   4641 	 *
   4642 	 * This is extremely likely to happen if pmap_enter() updated the L1
   4643 	 * entry for a recently entered mapping. In this case, the TLB is
   4644 	 * flushed for the new mapping, but there may still be TLB entries for
   4645 	 * other mappings belonging to other processes in the 1MB range
   4646 	 * covered by the L1 entry.
   4647 	 *
   4648 	 * Since 'rv == 0', we know that the L1 already contains the correct
   4649 	 * value, so the fault must be due to a stale TLB entry.
   4650 	 *
   4651 	 * Since we always need to flush the TLB anyway in the case where we
   4652 	 * fixed up the L1, or frobbed the L2 PTE, we effectively deal with
   4653 	 * stale TLB entries dynamically.
   4654 	 *
   4655 	 * However, the above condition can ONLY happen if the current L1 is
   4656 	 * being shared. If it happens when the L1 is unshared, it indicates
   4657 	 * that other parts of the pmap are not doing their job WRT managing
   4658 	 * the TLB.
   4659 	 */
   4660 	if (rv == 0
   4661 #ifndef ARM_MMU_EXTENDED
   4662 	    && pm->pm_l1->l1_domain_use_count == 1
   4663 #endif
   4664 	    && true) {
   4665 #ifdef DEBUG
   4666 		extern int last_fault_code;
   4667 #else
   4668 		int last_fault_code = ftype & VM_PROT_EXECUTE
   4669 		    ? armreg_ifsr_read()
   4670 		    : armreg_dfsr_read();
   4671 #endif
   4672 		printf("fixup: pm %p, va 0x%lx, ftype %d - nothing to do!\n",
   4673 		    pm, va, ftype);
   4674 		printf("fixup: l2 %p, l2b %p, ptep %p, pte %#x\n",
   4675 		    l2, l2b, ptep, opte);
   4676 
   4677 #ifndef ARM_MMU_EXTENDED
   4678 		printf("fixup: pdep %p, pde %#x, fsr %#x\n",
   4679 		    pdep, pde, last_fault_code);
   4680 #else
   4681 		printf("fixup: pdep %p, pde %#x, ttbcr %#x\n",
   4682 		    &pmap_l1_kva(pm)[l1slot], pmap_l1_kva(pm)[l1slot],
   4683 		   armreg_ttbcr_read());
   4684 		printf("fixup: fsr %#x cpm %p casid %#x contextidr %#x dacr %#x\n",
   4685 		    last_fault_code, curcpu()->ci_pmap_cur,
   4686 		    curcpu()->ci_pmap_asid_cur,
   4687 		    armreg_contextidr_read(), armreg_dacr_read());
   4688 #ifdef _ARM_ARCH_7
   4689 		if (ftype & VM_PROT_WRITE)
   4690 			armreg_ats1cuw_write(va);
   4691 		else
   4692 			armreg_ats1cur_write(va);
   4693 		arm_isb();
   4694 		printf("fixup: par %#x\n", armreg_par_read());
   4695 #endif
   4696 #endif
   4697 #ifdef DDB
   4698 		extern int kernel_debug;
   4699 
   4700 		if (kernel_debug & 2) {
   4701 			pmap_release_pmap_lock(pm);
   4702 #ifdef UVMHIST
   4703 			KERNHIST_DUMP(maphist);
   4704 #endif
   4705 			cpu_Debugger();
   4706 			pmap_acquire_pmap_lock(pm);
   4707 		}
   4708 #endif
   4709 	}
   4710 #endif
   4711 #endif
   4712 
   4713 #ifndef ARM_MMU_EXTENDED
   4714 	/* Flush the TLB in the shared L1 case - see comment above */
   4715 	pmap_tlb_flush_SE(pm, va,
   4716 	    (ftype & VM_PROT_EXECUTE) ? PVF_EXEC | PVF_REF : PVF_REF);
   4717 #endif
   4718 
   4719 	rv = 1;
   4720 
   4721 out:
   4722 	pmap_release_pmap_lock(pm);
   4723 
   4724 	return (rv);
   4725 }
   4726 
   4727 /*
   4728  * Routine:	pmap_procwr
   4729  *
   4730  * Function:
   4731  *	Synchronize caches corresponding to [addr, addr+len) in p.
   4732  *
   4733  */
   4734 void
   4735 pmap_procwr(struct proc *p, vaddr_t va, int len)
   4736 {
   4737 	/* We only need to do anything if it is the current process. */
   4738 	if (p == curproc)
   4739 		cpu_icache_sync_range(va, len);
   4740 }
   4741 
   4742 /*
   4743  * Routine:	pmap_unwire
   4744  * Function:	Clear the wired attribute for a map/virtual-address pair.
   4745  *
   4746  * In/out conditions:
   4747  *		The mapping must already exist in the pmap.
   4748  */
   4749 void
   4750 pmap_unwire(pmap_t pm, vaddr_t va)
   4751 {
   4752 	struct l2_bucket *l2b;
   4753 	pt_entry_t *ptep, pte;
   4754 	struct vm_page *pg;
   4755 	paddr_t pa;
   4756 
   4757 	NPDEBUG(PDB_WIRING, printf("pmap_unwire: pm %p, va 0x%08lx\n", pm, va));
   4758 
   4759 	pmap_acquire_pmap_lock(pm);
   4760 
   4761 	l2b = pmap_get_l2_bucket(pm, va);
   4762 	KDASSERT(l2b != NULL);
   4763 
   4764 	ptep = &l2b->l2b_kva[l2pte_index(va)];
   4765 	pte = *ptep;
   4766 
   4767 	/* Extract the physical address of the page */
   4768 	pa = l2pte_pa(pte);
   4769 
   4770 	if ((pg = PHYS_TO_VM_PAGE(pa)) != NULL) {
   4771 		/* Update the wired bit in the pv entry for this page. */
   4772 		struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   4773 
   4774 		pmap_acquire_page_lock(md);
   4775 		(void) pmap_modify_pv(md, pa, pm, va, PVF_WIRED, 0);
   4776 		pmap_release_page_lock(md);
   4777 	}
   4778 
   4779 	pmap_release_pmap_lock(pm);
   4780 }
   4781 
   4782 void
   4783 pmap_activate(struct lwp *l)
   4784 {
   4785 	struct cpu_info * const ci = curcpu();
   4786 	extern int block_userspace_access;
   4787 	pmap_t npm = l->l_proc->p_vmspace->vm_map.pmap;
   4788 #ifdef ARM_MMU_EXTENDED
   4789 	struct pmap_asid_info * const pai = PMAP_PAI(npm, cpu_tlb_info(ci));
   4790 #endif
   4791 
   4792 	UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
   4793 
   4794 	UVMHIST_LOG(maphist, "(l=%#x) pm=%#x", l, npm, 0, 0);
   4795 
   4796 	/*
   4797 	 * If activating a non-current lwp or the current lwp is
   4798 	 * already active, just return.
   4799 	 */
   4800 	if (false
   4801 	    || l != curlwp
   4802 #ifdef ARM_MMU_EXTENDED
   4803 	    || (ci->ci_pmap_cur == npm &&
   4804 		(npm == pmap_kernel()
   4805 		 /* || PMAP_PAI_ASIDVALID_P(pai, cpu_tlb_info(ci)) */))
   4806 #else
   4807 	    || npm->pm_activated == true
   4808 #endif
   4809 	    || false) {
   4810 		UVMHIST_LOG(maphist, " <-- (same pmap)", curlwp, l, 0, 0);
   4811 		return;
   4812 	}
   4813 
   4814 #ifndef ARM_MMU_EXTENDED
   4815 	const uint32_t ndacr = (DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL * 2))
   4816 	    | (DOMAIN_CLIENT << (pmap_domain(npm) * 2));
   4817 
   4818 	/*
   4819 	 * If TTB and DACR are unchanged, short-circuit all the
   4820 	 * TLB/cache management stuff.
   4821 	 */
   4822 	pmap_t opm = ci->ci_lastlwp
   4823 	    ? ci->ci_lastlwp->l_proc->p_vmspace->vm_map.pmap
   4824 	    : NULL;
   4825 	if (opm != NULL) {
   4826 		uint32_t odacr = (DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL * 2))
   4827 		    | (DOMAIN_CLIENT << (pmap_domain(opm) * 2));
   4828 
   4829 		if (opm->pm_l1 == npm->pm_l1 && odacr == ndacr)
   4830 			goto all_done;
   4831 	}
   4832 #endif /* !ARM_MMU_EXTENDED */
   4833 
   4834 	PMAPCOUNT(activations);
   4835 	block_userspace_access = 1;
   4836 
   4837 #ifndef ARM_MMU_EXTENDED
   4838 	/*
   4839 	 * If switching to a user vmspace which is different to the
   4840 	 * most recent one, and the most recent one is potentially
   4841 	 * live in the cache, we must write-back and invalidate the
   4842 	 * entire cache.
   4843 	 */
   4844 	pmap_t rpm = ci->ci_pmap_lastuser;
   4845 #endif
   4846 
   4847 /*
   4848  * XXXSCW: There's a corner case here which can leave turds in the cache as
   4849  * reported in kern/41058. They're probably left over during tear-down and
   4850  * switching away from an exiting process. Until the root cause is identified
   4851  * and fixed, zap the cache when switching pmaps. This will result in a few
   4852  * unnecessary cache flushes, but that's better than silently corrupting data.
   4853  */
   4854 #ifndef ARM_MMU_EXTENDED
   4855 #if 0
   4856 	if (npm != pmap_kernel() && rpm && npm != rpm &&
   4857 	    rpm->pm_cstate.cs_cache) {
   4858 		rpm->pm_cstate.cs_cache = 0;
   4859 #ifdef PMAP_CACHE_VIVT
   4860 		cpu_idcache_wbinv_all();
   4861 #endif
   4862 	}
   4863 #else
   4864 	if (rpm) {
   4865 		rpm->pm_cstate.cs_cache = 0;
   4866 		if (npm == pmap_kernel())
   4867 			ci->ci_pmap_lastuser = NULL;
   4868 #ifdef PMAP_CACHE_VIVT
   4869 		cpu_idcache_wbinv_all();
   4870 #endif
   4871 	}
   4872 #endif
   4873 
   4874 	/* No interrupts while we frob the TTB/DACR */
   4875 	uint32_t oldirqstate = disable_interrupts(IF32_bits);
   4876 #endif /* !ARM_MMU_EXTENDED */
   4877 
   4878 #ifndef ARM_HAS_VBAR
   4879 	/*
   4880 	 * For ARM_VECTORS_LOW, we MUST, I repeat, MUST fix up the L1
   4881 	 * entry corresponding to 'vector_page' in the incoming L1 table
   4882 	 * before switching to it otherwise subsequent interrupts/exceptions
   4883 	 * (including domain faults!) will jump into hyperspace.
   4884 	 */
   4885 	if (npm->pm_pl1vec != NULL) {
   4886 		cpu_tlb_flushID_SE((u_int)vector_page);
   4887 		cpu_cpwait();
   4888 		*npm->pm_pl1vec = npm->pm_l1vec;
   4889 		PTE_SYNC(npm->pm_pl1vec);
   4890 	}
   4891 #endif
   4892 
   4893 #ifdef ARM_MMU_EXTENDED
   4894 	/*
   4895 	 * Assume that TTBR1 has only global mappings and TTBR0 only has
   4896 	 * non-global mappings.  To prevent speculation from doing evil things
   4897 	 * we disable translation table walks using TTBR0 before setting the
   4898 	 * CONTEXTIDR (ASID) or new TTBR0 value.  Once both are set, table
   4899 	 * walks are reenabled.
   4900 	 */
   4901 	UVMHIST_LOG(maphist, " acquiring asid", 0, 0, 0, 0);
   4902 	const uint32_t old_ttbcr = armreg_ttbcr_read();
   4903 	armreg_ttbcr_write(old_ttbcr | TTBCR_S_PD0);
   4904 	arm_isb();
   4905 	pmap_tlb_asid_acquire(npm, l);
   4906 	UVMHIST_LOG(maphist, " setting ttbr pa=%#x asid=%#x", npm->pm_l1_pa, pai->pai_asid, 0, 0);
   4907 	cpu_setttb(npm->pm_l1_pa, pai->pai_asid);
   4908 	/*
   4909 	 * Now we can reenable tablewalks since the CONTEXTIDR and TTRB0 have
   4910 	 * been updated.
   4911 	 */
   4912 	arm_isb();
   4913 	if (npm != pmap_kernel()) {
   4914 		armreg_ttbcr_write(old_ttbcr & ~TTBCR_S_PD0);
   4915 	}
   4916 	cpu_cpwait();
   4917 	ci->ci_pmap_asid_cur = pai->pai_asid;
   4918 #else
   4919 	cpu_domains(ndacr);
   4920 	if (npm == pmap_kernel() || npm == rpm) {
   4921 		/*
   4922 		 * Switching to a kernel thread, or back to the
   4923 		 * same user vmspace as before... Simply update
   4924 		 * the TTB (no TLB flush required)
   4925 		 */
   4926 		cpu_setttb(npm->pm_l1->l1_physaddr, false);
   4927 		cpu_cpwait();
   4928 	} else {
   4929 		/*
   4930 		 * Otherwise, update TTB and flush TLB
   4931 		 */
   4932 		cpu_context_switch(npm->pm_l1->l1_physaddr);
   4933 		if (rpm != NULL)
   4934 			rpm->pm_cstate.cs_tlb = 0;
   4935 	}
   4936 
   4937 	restore_interrupts(oldirqstate);
   4938 #endif /* ARM_MMU_EXTENDED */
   4939 
   4940 	block_userspace_access = 0;
   4941 
   4942 #ifndef ARM_MMU_EXTENDED
   4943  all_done:
   4944 	/*
   4945 	 * The new pmap is resident. Make sure it's marked
   4946 	 * as resident in the cache/TLB.
   4947 	 */
   4948 	npm->pm_cstate.cs_all = PMAP_CACHE_STATE_ALL;
   4949 	if (npm != pmap_kernel())
   4950 		ci->ci_pmap_lastuser = npm;
   4951 
   4952 	/* The old pmap is not longer active */
   4953 	if (opm != npm) {
   4954 		if (opm != NULL)
   4955 			opm->pm_activated = false;
   4956 
   4957 		/* But the new one is */
   4958 		npm->pm_activated = true;
   4959 	}
   4960 #endif
   4961 	ci->ci_pmap_cur = npm;
   4962 	UVMHIST_LOG(maphist, " <-- done", 0, 0, 0, 0);
   4963 }
   4964 
   4965 void
   4966 pmap_deactivate(struct lwp *l)
   4967 {
   4968 	pmap_t pm = l->l_proc->p_vmspace->vm_map.pmap;
   4969 
   4970 	UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
   4971 
   4972 	UVMHIST_LOG(maphist, "(l=%#x) pm=%#x", l, pm, 0, 0);
   4973 
   4974 #ifdef ARM_MMU_EXTENDED
   4975 	kpreempt_disable();
   4976 	struct cpu_info * const ci = curcpu();
   4977 	/*
   4978 	 * Disable translation table walks from TTBR0 while no pmap has been
   4979 	 * activated.
   4980 	 */
   4981 	const uint32_t old_ttbcr = armreg_ttbcr_read();
   4982 	armreg_ttbcr_write(old_ttbcr | TTBCR_S_PD0);
   4983 	arm_isb();
   4984 	pmap_tlb_asid_deactivate(pm);
   4985 	cpu_setttb(pmap_kernel()->pm_l1_pa, KERNEL_PID);
   4986 	ci->ci_pmap_cur = pmap_kernel();
   4987 	ci->ci_pmap_asid_cur = KERNEL_PID;
   4988 	kpreempt_enable();
   4989 #else
   4990 	/*
   4991 	 * If the process is exiting, make sure pmap_activate() does
   4992 	 * a full MMU context-switch and cache flush, which we might
   4993 	 * otherwise skip. See PR port-arm/38950.
   4994 	 */
   4995 	if (l->l_proc->p_sflag & PS_WEXIT)
   4996 		curcpu()->ci_lastlwp = NULL;
   4997 
   4998 	pm->pm_activated = false;
   4999 #endif
   5000 	UVMHIST_LOG(maphist, "  <-- done", 0, 0, 0, 0);
   5001 }
   5002 
   5003 void
   5004 pmap_update(pmap_t pm)
   5005 {
   5006 
   5007 	if (pm->pm_remove_all) {
   5008 #ifdef ARM_MMU_EXTENDED
   5009 		KASSERT(pm != pmap_kernel());
   5010 
   5011 		KASSERTMSG(curcpu()->ci_pmap_cur != pm
   5012 		    || pm->pm_pai[0].pai_asid == curcpu()->ci_pmap_asid_cur,
   5013 		    "pmap/asid %p/%#x != %s cur pmap/asid %p/%#x", pm,
   5014 		    pm->pm_pai[0].pai_asid, curcpu()->ci_data.cpu_name,
   5015 		    curcpu()->ci_pmap_cur, curcpu()->ci_pmap_asid_cur);
   5016 
   5017 #ifdef MULTIPROCESSOR
   5018 		/*
   5019 		 * Finish up the pmap_remove_all() optimisation by flushing
   5020 		 * all our ASIDs.
   5021 		 */
   5022 		// This should be the last CPU with this pmap onproc
   5023 		KASSERT(!kcpuset_isotherset(pm->pm_onproc, cpu_index(curcpu())));
   5024 		if (kcpuset_isset(pm->pm_onproc, cpu_index(curcpu()))) {
   5025 			if (pm != pmap_kernel()) {
   5026 				struct cpu_info * const ci = curcpu();
   5027 				KASSERT(!cpu_intr_p());
   5028 				/*
   5029 				 * The bits in pm_onproc that belong to this
   5030 				 * TLB can be changed while this TLBs lock is
   5031 				 * not held as long as we use atomic ops.
   5032 				 */
   5033 				kcpuset_atomic_clear(pm->pm_onproc,
   5034 				    cpu_index(ci));
   5035 			}
   5036 		}
   5037 		KASSERT(kcpuset_iszero(pm->pm_onproc));
   5038 #endif
   5039 		struct pmap_asid_info * const pai =
   5040 		    PMAP_PAI(pm, cpu_tlb_info(ci));
   5041 
   5042 		tlb_invalidate_asids(pai->pai_asid, pai->pai_asid);
   5043 
   5044 #else
   5045 		/*
   5046 		 * Finish up the pmap_remove_all() optimisation by flushing
   5047 		 * the TLB.
   5048 		 */
   5049 		pmap_tlb_flushID(pm);
   5050 #endif
   5051 		pm->pm_remove_all = false;
   5052 	}
   5053 
   5054 #ifdef ARM_MMU_EXTENDED
   5055 #if defined(MULTIPROCESSOR)
   5056 	armreg_bpiallis_write(0);
   5057 #else
   5058 	armreg_bpiall_write(0);
   5059 #endif
   5060 
   5061 #if defined(MULTIPROCESSOR) && PMAP_TLB_MAX > 1
   5062 	u_int pending = atomic_swap_uint(&pmap->pm_shootdown_pending, 0);
   5063 	if (pending && pmap_tlb_shootdown_bystanders(pmap)) {
   5064 		PMAP_COUNT(shootdown_ipis);
   5065 	}
   5066 #endif
   5067 	KASSERTMSG(pm == pmap_kernel()
   5068 	    || curcpu()->ci_pmap_cur != pm
   5069 	    || pm->pm_pai[0].pai_asid == curcpu()->ci_pmap_asid_cur,
   5070 	    "pmap/asid %p/%#x != %s cur pmap/asid %p/%#x", pm,
   5071 	    pm->pm_pai[0].pai_asid, curcpu()->ci_data.cpu_name,
   5072 	    curcpu()->ci_pmap_cur, curcpu()->ci_pmap_asid_cur);
   5073 #else
   5074 	if (pmap_is_current(pm)) {
   5075 		/*
   5076 		 * If we're dealing with a current userland pmap, move its L1
   5077 		 * to the end of the LRU.
   5078 		 */
   5079 		if (pm != pmap_kernel())
   5080 			pmap_use_l1(pm);
   5081 
   5082 		/*
   5083 		 * We can assume we're done with frobbing the cache/tlb for
   5084 		 * now. Make sure any future pmap ops don't skip cache/tlb
   5085 		 * flushes.
   5086 		 */
   5087 		pm->pm_cstate.cs_all = PMAP_CACHE_STATE_ALL;
   5088 	}
   5089 #endif
   5090 
   5091 	PMAPCOUNT(updates);
   5092 
   5093 	/*
   5094 	 * make sure TLB/cache operations have completed.
   5095 	 */
   5096 	cpu_cpwait();
   5097 }
   5098 
   5099 void
   5100 pmap_remove_all(pmap_t pm)
   5101 {
   5102 
   5103 	/*
   5104 	 * The vmspace described by this pmap is about to be torn down.
   5105 	 * Until pmap_update() is called, UVM will only make calls
   5106 	 * to pmap_remove(). We can make life much simpler by flushing
   5107 	 * the cache now, and deferring TLB invalidation to pmap_update().
   5108 	 */
   5109 #ifdef PMAP_CACHE_VIVT
   5110 	pmap_cache_wbinv_all(pm, PVF_EXEC);
   5111 #endif
   5112 	pm->pm_remove_all = true;
   5113 }
   5114 
   5115 /*
   5116  * Retire the given physical map from service.
   5117  * Should only be called if the map contains no valid mappings.
   5118  */
   5119 void
   5120 pmap_destroy(pmap_t pm)
   5121 {
   5122 	u_int count;
   5123 
   5124 	if (pm == NULL)
   5125 		return;
   5126 
   5127 	if (pm->pm_remove_all) {
   5128 		pmap_tlb_flushID(pm);
   5129 		pm->pm_remove_all = false;
   5130 	}
   5131 
   5132 	/*
   5133 	 * Drop reference count
   5134 	 */
   5135 	mutex_enter(pm->pm_lock);
   5136 	count = --pm->pm_obj.uo_refs;
   5137 	mutex_exit(pm->pm_lock);
   5138 	if (count > 0) {
   5139 #ifndef ARM_MMU_EXTENDED
   5140 		if (pmap_is_current(pm)) {
   5141 			if (pm != pmap_kernel())
   5142 				pmap_use_l1(pm);
   5143 			pm->pm_cstate.cs_all = PMAP_CACHE_STATE_ALL;
   5144 		}
   5145 #endif
   5146 		return;
   5147 	}
   5148 
   5149 	/*
   5150 	 * reference count is zero, free pmap resources and then free pmap.
   5151 	 */
   5152 
   5153 #ifndef ARM_HAS_VBAR
   5154 	if (vector_page < KERNEL_BASE) {
   5155 		KDASSERT(!pmap_is_current(pm));
   5156 
   5157 		/* Remove the vector page mapping */
   5158 		pmap_remove(pm, vector_page, vector_page + PAGE_SIZE);
   5159 		pmap_update(pm);
   5160 	}
   5161 #endif
   5162 
   5163 	pmap_free_l1(pm);
   5164 
   5165 #ifdef ARM_MMU_EXTENDED
   5166 #ifdef MULTIPROCESSOR
   5167 	kcpuset_destroy(pm->pm_active);
   5168 	kcpuset_destroy(pm->pm_onproc);
   5169 #endif
   5170 #else
   5171 	struct cpu_info * const ci = curcpu();
   5172 	if (ci->ci_pmap_lastuser == pm)
   5173 		ci->ci_pmap_lastuser = NULL;
   5174 #endif
   5175 
   5176 	uvm_obj_destroy(&pm->pm_obj, false);
   5177 	mutex_destroy(&pm->pm_obj_lock);
   5178 	pool_cache_put(&pmap_cache, pm);
   5179 }
   5180 
   5181 
   5182 /*
   5183  * void pmap_reference(pmap_t pm)
   5184  *
   5185  * Add a reference to the specified pmap.
   5186  */
   5187 void
   5188 pmap_reference(pmap_t pm)
   5189 {
   5190 
   5191 	if (pm == NULL)
   5192 		return;
   5193 
   5194 #ifndef ARM_MMU_EXTENDED
   5195 	pmap_use_l1(pm);
   5196 #endif
   5197 
   5198 	mutex_enter(pm->pm_lock);
   5199 	pm->pm_obj.uo_refs++;
   5200 	mutex_exit(pm->pm_lock);
   5201 }
   5202 
   5203 #if (ARM_MMU_V6 + ARM_MMU_V7) > 0
   5204 
   5205 static struct evcnt pmap_prefer_nochange_ev =
   5206     EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "pmap prefer", "nochange");
   5207 static struct evcnt pmap_prefer_change_ev =
   5208     EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, "pmap prefer", "change");
   5209 
   5210 EVCNT_ATTACH_STATIC(pmap_prefer_change_ev);
   5211 EVCNT_ATTACH_STATIC(pmap_prefer_nochange_ev);
   5212 
   5213 void
   5214 pmap_prefer(vaddr_t hint, vaddr_t *vap, int td)
   5215 {
   5216 	vsize_t mask = arm_cache_prefer_mask | (PAGE_SIZE - 1);
   5217 	vaddr_t va = *vap;
   5218 	vaddr_t diff = (hint - va) & mask;
   5219 	if (diff == 0) {
   5220 		pmap_prefer_nochange_ev.ev_count++;
   5221 	} else {
   5222 		pmap_prefer_change_ev.ev_count++;
   5223 		if (__predict_false(td))
   5224 			va -= mask + 1;
   5225 		*vap = va + diff;
   5226 	}
   5227 }
   5228 #endif /* ARM_MMU_V6 | ARM_MMU_V7 */
   5229 
   5230 /*
   5231  * pmap_zero_page()
   5232  *
   5233  * Zero a given physical page by mapping it at a page hook point.
   5234  * In doing the zero page op, the page we zero is mapped cachable, as with
   5235  * StrongARM accesses to non-cached pages are non-burst making writing
   5236  * _any_ bulk data very slow.
   5237  */
   5238 #if (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6 + ARM_MMU_V7) != 0
   5239 void
   5240 pmap_zero_page_generic(paddr_t pa)
   5241 {
   5242 #if defined(PMAP_CACHE_VIPT) || defined(DEBUG)
   5243 	struct vm_page *pg = PHYS_TO_VM_PAGE(pa);
   5244 	struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   5245 #endif
   5246 #if defined(PMAP_CACHE_VIPT)
   5247 	/* Choose the last page color it had, if any */
   5248 	const vsize_t va_offset = md->pvh_attrs & arm_cache_prefer_mask;
   5249 #else
   5250 	const vsize_t va_offset = 0;
   5251 #endif
   5252 #if defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS)
   5253 	/*
   5254 	 * Is this page mapped at its natural color?
   5255 	 * If we have all of memory mapped, then just convert PA to VA.
   5256 	 */
   5257 	bool okcolor = arm_pcache.dcache_type == CACHE_TYPE_PIPT
   5258 	   || va_offset == (pa & arm_cache_prefer_mask);
   5259 	const vaddr_t vdstp = okcolor
   5260 	    ? pmap_direct_mapped_phys(pa, &okcolor, cpu_cdstp(va_offset))
   5261 	    : cpu_cdstp(va_offset);
   5262 #else
   5263 	const bool okcolor = false;
   5264 	const vaddr_t vdstp = cpu_cdstp(va_offset);
   5265 #endif
   5266 	pt_entry_t * const ptep = cpu_cdst_pte(va_offset);
   5267 
   5268 
   5269 #ifdef DEBUG
   5270 	if (!SLIST_EMPTY(&md->pvh_list))
   5271 		panic("pmap_zero_page: page has mappings");
   5272 #endif
   5273 
   5274 	KDASSERT((pa & PGOFSET) == 0);
   5275 
   5276 	if (!okcolor) {
   5277 		/*
   5278 		 * Hook in the page, zero it, and purge the cache for that
   5279 		 * zeroed page. Invalidate the TLB as needed.
   5280 		 */
   5281 		const pt_entry_t npte = L2_S_PROTO | pa | pte_l2_s_cache_mode
   5282 		    | L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE);
   5283 		l2pte_set(ptep, npte, 0);
   5284 		PTE_SYNC(ptep);
   5285 		cpu_tlb_flushD_SE(vdstp);
   5286 		cpu_cpwait();
   5287 #if defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS) && defined(PMAP_CACHE_VIPT) \
   5288     && !defined(ARM_MMU_EXTENDED)
   5289 		/*
   5290 		 * If we are direct-mapped and our color isn't ok, then before
   5291 		 * we bzero the page invalidate its contents from the cache and
   5292 		 * reset the color to its natural color.
   5293 		 */
   5294 		cpu_dcache_inv_range(vdstp, PAGE_SIZE);
   5295 		md->pvh_attrs &= ~arm_cache_prefer_mask;
   5296 		md->pvh_attrs |= (pa & arm_cache_prefer_mask);
   5297 #endif
   5298 	}
   5299 	bzero_page(vdstp);
   5300 	if (!okcolor) {
   5301 		/*
   5302 		 * Unmap the page.
   5303 		 */
   5304 		l2pte_reset(ptep);
   5305 		PTE_SYNC(ptep);
   5306 		cpu_tlb_flushD_SE(vdstp);
   5307 #ifdef PMAP_CACHE_VIVT
   5308 		cpu_dcache_wbinv_range(vdstp, PAGE_SIZE);
   5309 #endif
   5310 	}
   5311 #ifdef PMAP_CACHE_VIPT
   5312 	/*
   5313 	 * This page is now cache resident so it now has a page color.
   5314 	 * Any contents have been obliterated so clear the EXEC flag.
   5315 	 */
   5316 #ifndef ARM_MMU_EXTENDED
   5317 	if (!pmap_is_page_colored_p(md)) {
   5318 		PMAPCOUNT(vac_color_new);
   5319 		md->pvh_attrs |= PVF_COLORED;
   5320 	}
   5321 	md->pvh_attrs |= PVF_DIRTY;
   5322 #endif
   5323 	if (PV_IS_EXEC_P(md->pvh_attrs)) {
   5324 		md->pvh_attrs &= ~PVF_EXEC;
   5325 		PMAPCOUNT(exec_discarded_zero);
   5326 	}
   5327 #endif
   5328 }
   5329 #endif /* (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6) != 0 */
   5330 
   5331 #if ARM_MMU_XSCALE == 1
   5332 void
   5333 pmap_zero_page_xscale(paddr_t pa)
   5334 {
   5335 #ifdef DEBUG
   5336 	struct vm_page *pg = PHYS_TO_VM_PAGE(pa);
   5337 	struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   5338 
   5339 	if (!SLIST_EMPTY(&md->pvh_list))
   5340 		panic("pmap_zero_page: page has mappings");
   5341 #endif
   5342 
   5343 	KDASSERT((pa & PGOFSET) == 0);
   5344 
   5345 	/*
   5346 	 * Hook in the page, zero it, and purge the cache for that
   5347 	 * zeroed page. Invalidate the TLB as needed.
   5348 	 */
   5349 
   5350 	pt_entry_t npte = L2_S_PROTO | pa |
   5351 	    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) |
   5352 	    L2_C | L2_XS_T_TEX(TEX_XSCALE_X);	/* mini-data */
   5353 	l2pte_set(cdst_pte, npte, 0);
   5354 	PTE_SYNC(cdst_pte);
   5355 	cpu_tlb_flushD_SE(cdstp);
   5356 	cpu_cpwait();
   5357 	bzero_page(cdstp);
   5358 	xscale_cache_clean_minidata();
   5359 	l2pte_reset(cdst_pte);
   5360 	PTE_SYNC(cdst_pte);
   5361 }
   5362 #endif /* ARM_MMU_XSCALE == 1 */
   5363 
   5364 /* pmap_pageidlezero()
   5365  *
   5366  * The same as above, except that we assume that the page is not
   5367  * mapped.  This means we never have to flush the cache first.  Called
   5368  * from the idle loop.
   5369  */
   5370 bool
   5371 pmap_pageidlezero(paddr_t pa)
   5372 {
   5373 	bool rv = true;
   5374 #if defined(PMAP_CACHE_VIPT) || defined(DEBUG)
   5375 	struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
   5376 	struct vm_page_md *md = VM_PAGE_TO_MD(pg);
   5377 #endif
   5378 #ifdef PMAP_CACHE_VIPT
   5379 	/* Choose the last page color it had, if any */
   5380 	const vsize_t va_offset = md->pvh_attrs & arm_cache_prefer_mask;
   5381 #else
   5382 	const vsize_t va_offset = 0;
   5383 #endif
   5384 #ifdef __HAVE_MM_MD_DIRECT_MAPPED_PHYS
   5385 	bool okcolor = arm_pcache.dcache_type == CACHE_TYPE_PIPT
   5386 	   || va_offset == (pa & arm_cache_prefer_mask);
   5387 	const vaddr_t vdstp = okcolor
   5388 	    ? pmap_direct_mapped_phys(pa, &okcolor, cpu_cdstp(va_offset))
   5389 	    : cpu_cdstp(va_offset);
   5390 #else
   5391 	const bool okcolor = false;
   5392 	const vaddr_t vdstp = cpu_cdstp(va_offset);
   5393 #endif
   5394 	pt_entry_t * const ptep = cpu_cdst_pte(va_offset);
   5395 
   5396 
   5397 #ifdef DEBUG
   5398 	if (!SLIST_EMPTY(&md->pvh_list))
   5399 		panic("pmap_pageidlezero: page has mappings");
   5400 #endif
   5401 
   5402 	KDASSERT((pa & PGOFSET) == 0);
   5403 
   5404 	if (!okcolor) {
   5405 		/*
   5406 		 * Hook in the page, zero it, and purge the cache for that
   5407 		 * zeroed page. Invalidate the TLB as needed.
   5408 		 */
   5409 		const pt_entry_t npte = L2_S_PROTO | pa |
   5410 		    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) | pte_l2_s_cache_mode;
   5411 		l2pte_set(ptep, npte, 0);
   5412 		PTE_SYNC(ptep);
   5413 		cpu_tlb_flushD_SE(vdstp);
   5414 		cpu_cpwait();
   5415 	}
   5416 
   5417 	uint64_t *ptr = (uint64_t *)vdstp;
   5418 	for (size_t i = 0; i < PAGE_SIZE / sizeof(*ptr); i++) {
   5419 		if (sched_curcpu_runnable_p() != 0) {
   5420 			/*
   5421 			 * A process has become ready.  Abort now,
   5422 			 * so we don't keep it waiting while we
   5423 			 * do slow memory access to finish this
   5424 			 * page.
   5425 			 */
   5426 			rv = false;
   5427 			break;
   5428 		}
   5429 		*ptr++ = 0;
   5430 	}
   5431 
   5432 #ifdef PMAP_CACHE_VIVT
   5433 	if (rv)
   5434 		/*
   5435 		 * if we aborted we'll rezero this page again later so don't
   5436 		 * purge it unless we finished it
   5437 		 */
   5438 		cpu_dcache_wbinv_range(vdstp, PAGE_SIZE);
   5439 #elif defined(PMAP_CACHE_VIPT)
   5440 	/*
   5441 	 * This page is now cache resident so it now has a page color.
   5442 	 * Any contents have been obliterated so clear the EXEC flag.
   5443 	 */
   5444 #ifndef ARM_MMU_EXTENDED
   5445 	if (!pmap_is_page_colored_p(md)) {
   5446 		PMAPCOUNT(vac_color_new);
   5447 		md->pvh_attrs |= PVF_COLORED;
   5448 	}
   5449 #endif
   5450 	if (PV_IS_EXEC_P(md->pvh_attrs)) {
   5451 		md->pvh_attrs &= ~PVF_EXEC;
   5452 		PMAPCOUNT(exec_discarded_zero);
   5453 	}
   5454 #endif
   5455 	/*
   5456 	 * Unmap the page.
   5457 	 */
   5458 	if (!okcolor) {
   5459 		l2pte_reset(ptep);
   5460 		PTE_SYNC(ptep);
   5461 		cpu_tlb_flushD_SE(vdstp);
   5462 	}
   5463 
   5464 	return rv;
   5465 }
   5466 
   5467 /*
   5468  * pmap_copy_page()
   5469  *
   5470  * Copy one physical page into another, by mapping the pages into
   5471  * hook points. The same comment regarding cachability as in
   5472  * pmap_zero_page also applies here.
   5473  */
   5474 #if (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6 + ARM_MMU_V7) != 0
   5475 void
   5476 pmap_copy_page_generic(paddr_t src, paddr_t dst)
   5477 {
   5478 	struct vm_page * const src_pg = PHYS_TO_VM_PAGE(src);
   5479 	struct vm_page_md *src_md = VM_PAGE_TO_MD(src_pg);
   5480 #if defined(PMAP_CACHE_VIPT) || defined(DEBUG)
   5481 	struct vm_page * const dst_pg = PHYS_TO_VM_PAGE(dst);
   5482 	struct vm_page_md *dst_md = VM_PAGE_TO_MD(dst_pg);
   5483 #endif
   5484 #ifdef PMAP_CACHE_VIPT
   5485 	const vsize_t src_va_offset = src_md->pvh_attrs & arm_cache_prefer_mask;
   5486 	const vsize_t dst_va_offset = dst_md->pvh_attrs & arm_cache_prefer_mask;
   5487 #else
   5488 	const vsize_t src_va_offset = 0;
   5489 	const vsize_t dst_va_offset = 0;
   5490 #endif
   5491 #if defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS)
   5492 	/*
   5493 	 * Is this page mapped at its natural color?
   5494 	 * If we have all of memory mapped, then just convert PA to VA.
   5495 	 */
   5496 	bool src_okcolor = arm_pcache.dcache_type == CACHE_TYPE_PIPT
   5497 	    || src_va_offset == (src & arm_cache_prefer_mask);
   5498 	bool dst_okcolor = arm_pcache.dcache_type == CACHE_TYPE_PIPT
   5499 	    || dst_va_offset == (dst & arm_cache_prefer_mask);
   5500 	const vaddr_t vsrcp = src_okcolor
   5501 	    ? pmap_direct_mapped_phys(src, &src_okcolor,
   5502 		cpu_csrcp(src_va_offset))
   5503 	    : cpu_csrcp(src_va_offset);
   5504 	const vaddr_t vdstp = pmap_direct_mapped_phys(dst, &dst_okcolor,
   5505 	    cpu_cdstp(dst_va_offset));
   5506 #else
   5507 	const bool src_okcolor = false;
   5508 	const bool dst_okcolor = false;
   5509 	const vaddr_t vsrcp = cpu_csrcp(src_va_offset);
   5510 	const vaddr_t vdstp = cpu_cdstp(dst_va_offset);
   5511 #endif
   5512 	pt_entry_t * const src_ptep = cpu_csrc_pte(src_va_offset);
   5513 	pt_entry_t * const dst_ptep = cpu_cdst_pte(dst_va_offset);
   5514 
   5515 #ifdef DEBUG
   5516 	if (!SLIST_EMPTY(&dst_md->pvh_list))
   5517 		panic("pmap_copy_page: dst page has mappings");
   5518 #endif
   5519 
   5520 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   5521 	KASSERT(arm_cache_prefer_mask == 0 || src_md->pvh_attrs & (PVF_COLORED|PVF_NC));
   5522 #endif
   5523 	KDASSERT((src & PGOFSET) == 0);
   5524 	KDASSERT((dst & PGOFSET) == 0);
   5525 
   5526 	/*
   5527 	 * Clean the source page.  Hold the source page's lock for
   5528 	 * the duration of the copy so that no other mappings can
   5529 	 * be created while we have a potentially aliased mapping.
   5530 	 */
   5531 #ifdef PMAP_CACHE_VIVT
   5532 	pmap_acquire_page_lock(src_md);
   5533 	(void) pmap_clean_page(src_md, true);
   5534 	pmap_release_page_lock(src_md);
   5535 #endif
   5536 
   5537 	/*
   5538 	 * Map the pages into the page hook points, copy them, and purge
   5539 	 * the cache for the appropriate page. Invalidate the TLB
   5540 	 * as required.
   5541 	 */
   5542 	if (!src_okcolor) {
   5543 		const pt_entry_t nsrc_pte = L2_S_PROTO
   5544 		    | src
   5545 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   5546 		    | ((src_md->pvh_attrs & PVF_NC) ? 0 : pte_l2_s_cache_mode)
   5547 #else // defined(PMAP_CACHE_VIVT) || defined(ARM_MMU_EXTENDED)
   5548 		    | pte_l2_s_cache_mode
   5549 #endif
   5550 		    | L2_S_PROT(PTE_KERNEL, VM_PROT_READ);
   5551 		l2pte_set(src_ptep, nsrc_pte, 0);
   5552 		PTE_SYNC(src_ptep);
   5553 		cpu_tlb_flushD_SE(vsrcp);
   5554 		cpu_cpwait();
   5555 	}
   5556 	if (!dst_okcolor) {
   5557 		const pt_entry_t ndst_pte = L2_S_PROTO | dst |
   5558 		    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) | pte_l2_s_cache_mode;
   5559 		l2pte_set(dst_ptep, ndst_pte, 0);
   5560 		PTE_SYNC(dst_ptep);
   5561 		cpu_tlb_flushD_SE(vdstp);
   5562 		cpu_cpwait();
   5563 #if defined(__HAVE_MM_MD_DIRECT_MAPPED_PHYS) && defined(PMAP_CACHE_VIPT)
   5564 		/*
   5565 		 * If we are direct-mapped and our color isn't ok, then before
   5566 		 * we bcopy to the new page invalidate its contents from the
   5567 		 * cache and reset its color to its natural color.
   5568 		 */
   5569 		cpu_dcache_inv_range(vdstp, PAGE_SIZE);
   5570 		dst_md->pvh_attrs &= ~arm_cache_prefer_mask;
   5571 		dst_md->pvh_attrs |= (dst & arm_cache_prefer_mask);
   5572 #endif
   5573 	}
   5574 	bcopy_page(vsrcp, vdstp);
   5575 #ifdef PMAP_CACHE_VIVT
   5576 	cpu_dcache_inv_range(vsrcp, PAGE_SIZE);
   5577 	cpu_dcache_wbinv_range(vdstp, PAGE_SIZE);
   5578 #endif
   5579 	/*
   5580 	 * Unmap the pages.
   5581 	 */
   5582 	if (!src_okcolor) {
   5583 		l2pte_reset(src_ptep);
   5584 		PTE_SYNC(src_ptep);
   5585 		cpu_tlb_flushD_SE(vsrcp);
   5586 		cpu_cpwait();
   5587 	}
   5588 	if (!dst_okcolor) {
   5589 		l2pte_reset(dst_ptep);
   5590 		PTE_SYNC(dst_ptep);
   5591 		cpu_tlb_flushD_SE(vdstp);
   5592 		cpu_cpwait();
   5593 	}
   5594 #ifdef PMAP_CACHE_VIPT
   5595 	/*
   5596 	 * Now that the destination page is in the cache, mark it as colored.
   5597 	 * If this was an exec page, discard it.
   5598 	 */
   5599 	pmap_acquire_page_lock(dst_md);
   5600 #ifndef ARM_MMU_EXTENDED
   5601 	if (arm_pcache.cache_type == CACHE_TYPE_PIPT) {
   5602 		dst_md->pvh_attrs &= ~arm_cache_prefer_mask;
   5603 		dst_md->pvh_attrs |= (dst & arm_cache_prefer_mask);
   5604 	}
   5605 	if (!pmap_is_page_colored_p(dst_md)) {
   5606 		PMAPCOUNT(vac_color_new);
   5607 		dst_md->pvh_attrs |= PVF_COLORED;
   5608 	}
   5609 	dst_md->pvh_attrs |= PVF_DIRTY;
   5610 #endif
   5611 	if (PV_IS_EXEC_P(dst_md->pvh_attrs)) {
   5612 		dst_md->pvh_attrs &= ~PVF_EXEC;
   5613 		PMAPCOUNT(exec_discarded_copy);
   5614 	}
   5615 	pmap_release_page_lock(dst_md);
   5616 #endif
   5617 }
   5618 #endif /* (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6) != 0 */
   5619 
   5620 #if ARM_MMU_XSCALE == 1
   5621 void
   5622 pmap_copy_page_xscale(paddr_t src, paddr_t dst)
   5623 {
   5624 	struct vm_page *src_pg = PHYS_TO_VM_PAGE(src);
   5625 	struct vm_page_md *src_md = VM_PAGE_TO_MD(src_pg);
   5626 #ifdef DEBUG
   5627 	struct vm_page_md *dst_md = VM_PAGE_TO_MD(PHYS_TO_VM_PAGE(dst));
   5628 
   5629 	if (!SLIST_EMPTY(&dst_md->pvh_list))
   5630 		panic("pmap_copy_page: dst page has mappings");
   5631 #endif
   5632 
   5633 	KDASSERT((src & PGOFSET) == 0);
   5634 	KDASSERT((dst & PGOFSET) == 0);
   5635 
   5636 	/*
   5637 	 * Clean the source page.  Hold the source page's lock for
   5638 	 * the duration of the copy so that no other mappings can
   5639 	 * be created while we have a potentially aliased mapping.
   5640 	 */
   5641 #ifdef PMAP_CACHE_VIVT
   5642 	pmap_acquire_page_lock(src_md);
   5643 	(void) pmap_clean_page(src_md, true);
   5644 	pmap_release_page_lock(src_md);
   5645 #endif
   5646 
   5647 	/*
   5648 	 * Map the pages into the page hook points, copy them, and purge
   5649 	 * the cache for the appropriate page. Invalidate the TLB
   5650 	 * as required.
   5651 	 */
   5652 	const pt_entry_t nsrc_pte = L2_S_PROTO | src
   5653 	    | L2_S_PROT(PTE_KERNEL, VM_PROT_READ)
   5654 	    | L2_C | L2_XS_T_TEX(TEX_XSCALE_X);	/* mini-data */
   5655 	l2pte_set(csrc_pte, nsrc_pte, 0);
   5656 	PTE_SYNC(csrc_pte);
   5657 
   5658 	const pt_entry_t ndst_pte = L2_S_PROTO | dst
   5659 	    | L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE)
   5660 	    | L2_C | L2_XS_T_TEX(TEX_XSCALE_X);	/* mini-data */
   5661 	l2pte_set(cdst_pte, ndst_pte, 0);
   5662 	PTE_SYNC(cdst_pte);
   5663 
   5664 	cpu_tlb_flushD_SE(csrcp);
   5665 	cpu_tlb_flushD_SE(cdstp);
   5666 	cpu_cpwait();
   5667 	bcopy_page(csrcp, cdstp);
   5668 	xscale_cache_clean_minidata();
   5669 	l2pte_reset(csrc_pte);
   5670 	l2pte_reset(cdst_pte);
   5671 	PTE_SYNC(csrc_pte);
   5672 	PTE_SYNC(cdst_pte);
   5673 }
   5674 #endif /* ARM_MMU_XSCALE == 1 */
   5675 
   5676 /*
   5677  * void pmap_virtual_space(vaddr_t *start, vaddr_t *end)
   5678  *
   5679  * Return the start and end addresses of the kernel's virtual space.
   5680  * These values are setup in pmap_bootstrap and are updated as pages
   5681  * are allocated.
   5682  */
   5683 void
   5684 pmap_virtual_space(vaddr_t *start, vaddr_t *end)
   5685 {
   5686 	*start = virtual_avail;
   5687 	*end = virtual_end;
   5688 }
   5689 
   5690 /*
   5691  * Helper function for pmap_grow_l2_bucket()
   5692  */
   5693 static inline int
   5694 pmap_grow_map(vaddr_t va, paddr_t *pap)
   5695 {
   5696 	paddr_t pa;
   5697 
   5698 	if (uvm.page_init_done == false) {
   5699 #ifdef PMAP_STEAL_MEMORY
   5700 		pv_addr_t pv;
   5701 		pmap_boot_pagealloc(PAGE_SIZE,
   5702 #ifdef PMAP_CACHE_VIPT
   5703 		    arm_cache_prefer_mask,
   5704 		    va & arm_cache_prefer_mask,
   5705 #else
   5706 		    0, 0,
   5707 #endif
   5708 		    &pv);
   5709 		pa = pv.pv_pa;
   5710 #else
   5711 		if (uvm_page_physget(&pa) == false)
   5712 			return (1);
   5713 #endif	/* PMAP_STEAL_MEMORY */
   5714 	} else {
   5715 		struct vm_page *pg;
   5716 		pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE);
   5717 		if (pg == NULL)
   5718 			return (1);
   5719 		pa = VM_PAGE_TO_PHYS(pg);
   5720 		/*
   5721 		 * This new page must not have any mappings.  Enter it via
   5722 		 * pmap_kenter_pa and let that routine do the hard work.
   5723 		 */
   5724 		struct vm_page_md *md __diagused = VM_PAGE_TO_MD(pg);
   5725 		KASSERT(SLIST_EMPTY(&md->pvh_list));
   5726 		pmap_kenter_pa(va, pa,
   5727 		    VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE|PMAP_PTE);
   5728 	}
   5729 
   5730 	if (pap)
   5731 		*pap = pa;
   5732 
   5733 	PMAPCOUNT(pt_mappings);
   5734 #ifdef DEBUG
   5735 	struct l2_bucket * const l2b = pmap_get_l2_bucket(pmap_kernel(), va);
   5736 	KDASSERT(l2b != NULL);
   5737 
   5738 	pt_entry_t * const ptep = &l2b->l2b_kva[l2pte_index(va)];
   5739 	const pt_entry_t opte = *ptep;
   5740 	KDASSERT((opte & L2_S_CACHE_MASK) == pte_l2_s_cache_mode_pt);
   5741 #endif
   5742 	memset((void *)va, 0, PAGE_SIZE);
   5743 	return (0);
   5744 }
   5745 
   5746 /*
   5747  * This is the same as pmap_alloc_l2_bucket(), except that it is only
   5748  * used by pmap_growkernel().
   5749  */
   5750 static inline struct l2_bucket *
   5751 pmap_grow_l2_bucket(pmap_t pm, vaddr_t va)
   5752 {
   5753 	struct l2_dtable *l2;
   5754 	struct l2_bucket *l2b;
   5755 	u_short l1slot;
   5756 	vaddr_t nva;
   5757 
   5758 	l1slot = l1pte_index(va);
   5759 
   5760 	if ((l2 = pm->pm_l2[L2_IDX(l1slot)]) == NULL) {
   5761 		/*
   5762 		 * No mapping at this address, as there is
   5763 		 * no entry in the L1 table.
   5764 		 * Need to allocate a new l2_dtable.
   5765 		 */
   5766 		nva = pmap_kernel_l2dtable_kva;
   5767 		if ((nva & PGOFSET) == 0) {
   5768 			/*
   5769 			 * Need to allocate a backing page
   5770 			 */
   5771 			if (pmap_grow_map(nva, NULL))
   5772 				return (NULL);
   5773 		}
   5774 
   5775 		l2 = (struct l2_dtable *)nva;
   5776 		nva += sizeof(struct l2_dtable);
   5777 
   5778 		if ((nva & PGOFSET) < (pmap_kernel_l2dtable_kva & PGOFSET)) {
   5779 			/*
   5780 			 * The new l2_dtable straddles a page boundary.
   5781 			 * Map in another page to cover it.
   5782 			 */
   5783 			if (pmap_grow_map(nva, NULL))
   5784 				return (NULL);
   5785 		}
   5786 
   5787 		pmap_kernel_l2dtable_kva = nva;
   5788 
   5789 		/*
   5790 		 * Link it into the parent pmap
   5791 		 */
   5792 		pm->pm_l2[L2_IDX(l1slot)] = l2;
   5793 	}
   5794 
   5795 	l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];
   5796 
   5797 	/*
   5798 	 * Fetch pointer to the L2 page table associated with the address.
   5799 	 */
   5800 	if (l2b->l2b_kva == NULL) {
   5801 		pt_entry_t *ptep;
   5802 
   5803 		/*
   5804 		 * No L2 page table has been allocated. Chances are, this
   5805 		 * is because we just allocated the l2_dtable, above.
   5806 		 */
   5807 		nva = pmap_kernel_l2ptp_kva;
   5808 		ptep = (pt_entry_t *)nva;
   5809 		if ((nva & PGOFSET) == 0) {
   5810 			/*
   5811 			 * Need to allocate a backing page
   5812 			 */
   5813 			if (pmap_grow_map(nva, &pmap_kernel_l2ptp_phys))
   5814 				return (NULL);
   5815 			PTE_SYNC_RANGE(ptep, PAGE_SIZE / sizeof(pt_entry_t));
   5816 		}
   5817 
   5818 		l2->l2_occupancy++;
   5819 		l2b->l2b_kva = ptep;
   5820 		l2b->l2b_l1slot = l1slot;
   5821 		l2b->l2b_pa = pmap_kernel_l2ptp_phys;
   5822 
   5823 		pmap_kernel_l2ptp_kva += L2_TABLE_SIZE_REAL;
   5824 		pmap_kernel_l2ptp_phys += L2_TABLE_SIZE_REAL;
   5825 	}
   5826 
   5827 	return (l2b);
   5828 }
   5829 
   5830 vaddr_t
   5831 pmap_growkernel(vaddr_t maxkvaddr)
   5832 {
   5833 	pmap_t kpm = pmap_kernel();
   5834 #ifndef ARM_MMU_EXTENDED
   5835 	struct l1_ttable *l1;
   5836 #endif
   5837 	int s;
   5838 
   5839 	if (maxkvaddr <= pmap_curmaxkvaddr)
   5840 		goto out;		/* we are OK */
   5841 
   5842 	NPDEBUG(PDB_GROWKERN,
   5843 	    printf("pmap_growkernel: growing kernel from 0x%lx to 0x%lx\n",
   5844 	    pmap_curmaxkvaddr, maxkvaddr));
   5845 
   5846 	KDASSERT(maxkvaddr <= virtual_end);
   5847 
   5848 	/*
   5849 	 * whoops!   we need to add kernel PTPs
   5850 	 */
   5851 
   5852 	s = splhigh();	/* to be safe */
   5853 	mutex_enter(kpm->pm_lock);
   5854 
   5855 	/* Map 1MB at a time */
   5856 	size_t l1slot = l1pte_index(pmap_curmaxkvaddr);
   5857 #ifdef ARM_MMU_EXTENDED
   5858 	pd_entry_t * const spdep = &kpm->pm_l1[l1slot];
   5859 	pd_entry_t *pdep = spdep;
   5860 #endif
   5861 	for (;pmap_curmaxkvaddr < maxkvaddr; pmap_curmaxkvaddr += L1_S_SIZE,
   5862 #ifdef ARM_MMU_EXTENDED
   5863 	     pdep++,
   5864 #endif
   5865 	     l1slot++) {
   5866 		struct l2_bucket *l2b =
   5867 		    pmap_grow_l2_bucket(kpm, pmap_curmaxkvaddr);
   5868 		KASSERT(l2b != NULL);
   5869 
   5870 		const pd_entry_t npde = L1_C_PROTO | l2b->l2b_pa
   5871 		    | L1_C_DOM(PMAP_DOMAIN_KERNEL);
   5872 #ifdef ARM_MMU_EXTENDED
   5873 		l1pte_setone(pdep, npde);
   5874 #else
   5875 		/* Distribute new L1 entry to all other L1s */
   5876 		SLIST_FOREACH(l1, &l1_list, l1_link) {
   5877 			pd_entry_t * const pdep = &l1->l1_kva[l1slot];
   5878 			l1pte_setone(pdep, npde);
   5879 			PDE_SYNC(pdep);
   5880 		}
   5881 #endif
   5882 	}
   5883 #ifdef ARM_MMU_EXTENDED
   5884 	PDE_SYNC_RANGE(spdep, pdep - spdep);
   5885 #endif
   5886 
   5887 #ifdef PMAP_CACHE_VIVT
   5888 	/*
   5889 	 * flush out the cache, expensive but growkernel will happen so
   5890 	 * rarely
   5891 	 */
   5892 	cpu_dcache_wbinv_all();
   5893 	cpu_tlb_flushD();
   5894 	cpu_cpwait();
   5895 #endif
   5896 
   5897 	mutex_exit(kpm->pm_lock);
   5898 	splx(s);
   5899 
   5900 out:
   5901 	return (pmap_curmaxkvaddr);
   5902 }
   5903 
   5904 /************************ Utility routines ****************************/
   5905 
   5906 #ifndef ARM_HAS_VBAR
   5907 /*
   5908  * vector_page_setprot:
   5909  *
   5910  *	Manipulate the protection of the vector page.
   5911  */
   5912 void
   5913 vector_page_setprot(int prot)
   5914 {
   5915 	struct l2_bucket *l2b;
   5916 	pt_entry_t *ptep;
   5917 
   5918 #if defined(CPU_ARMV7) || defined(CPU_ARM11)
   5919 	/*
   5920 	 * If we are using VBAR to use the vectors in the kernel, then it's
   5921 	 * already mapped in the kernel text so no need to anything here.
   5922 	 */
   5923 	if (vector_page != ARM_VECTORS_LOW && vector_page != ARM_VECTORS_HIGH) {
   5924 		KASSERT((armreg_pfr1_read() & ARM_PFR1_SEC_MASK) != 0);
   5925 		return;
   5926 	}
   5927 #endif
   5928 
   5929 	l2b = pmap_get_l2_bucket(pmap_kernel(), vector_page);
   5930 	KASSERT(l2b != NULL);
   5931 
   5932 	ptep = &l2b->l2b_kva[l2pte_index(vector_page)];
   5933 
   5934 	const pt_entry_t opte = *ptep;
   5935 #ifdef ARM_MMU_EXTENDED
   5936 	const pt_entry_t npte = (opte & ~(L2_S_PROT_MASK|L2_XS_XN))
   5937 	    | L2_S_PROT(PTE_KERNEL, prot);
   5938 #else
   5939 	const pt_entry_t npte = (opte & ~L2_S_PROT_MASK)
   5940 	    | L2_S_PROT(PTE_KERNEL, prot);
   5941 #endif
   5942 	l2pte_set(ptep, npte, opte);
   5943 	PTE_SYNC(ptep);
   5944 	cpu_tlb_flushD_SE(vector_page);
   5945 	cpu_cpwait();
   5946 }
   5947 #endif
   5948 
   5949 /*
   5950  * Fetch pointers to the PDE/PTE for the given pmap/VA pair.
   5951  * Returns true if the mapping exists, else false.
   5952  *
   5953  * NOTE: This function is only used by a couple of arm-specific modules.
   5954  * It is not safe to take any pmap locks here, since we could be right
   5955  * in the middle of debugging the pmap anyway...
   5956  *
   5957  * It is possible for this routine to return false even though a valid
   5958  * mapping does exist. This is because we don't lock, so the metadata
   5959  * state may be inconsistent.
   5960  *
   5961  * NOTE: We can return a NULL *ptp in the case where the L1 pde is
   5962  * a "section" mapping.
   5963  */
   5964 bool
   5965 pmap_get_pde_pte(pmap_t pm, vaddr_t va, pd_entry_t **pdp, pt_entry_t **ptp)
   5966 {
   5967 	struct l2_dtable *l2;
   5968 	pd_entry_t *pdep, pde;
   5969 	pt_entry_t *ptep;
   5970 	u_short l1slot;
   5971 
   5972 	if (pm->pm_l1 == NULL)
   5973 		return false;
   5974 
   5975 	l1slot = l1pte_index(va);
   5976 	*pdp = pdep = pmap_l1_kva(pm) + l1slot;
   5977 	pde = *pdep;
   5978 
   5979 	if (l1pte_section_p(pde)) {
   5980 		*ptp = NULL;
   5981 		return true;
   5982 	}
   5983 
   5984 	l2 = pm->pm_l2[L2_IDX(l1slot)];
   5985 	if (l2 == NULL ||
   5986 	    (ptep = l2->l2_bucket[L2_BUCKET(l1slot)].l2b_kva) == NULL) {
   5987 		return false;
   5988 	}
   5989 
   5990 	*ptp = &ptep[l2pte_index(va)];
   5991 	return true;
   5992 }
   5993 
   5994 bool
   5995 pmap_get_pde(pmap_t pm, vaddr_t va, pd_entry_t **pdp)
   5996 {
   5997 
   5998 	if (pm->pm_l1 == NULL)
   5999 		return false;
   6000 
   6001 	*pdp = pmap_l1_kva(pm) + l1pte_index(va);
   6002 
   6003 	return true;
   6004 }
   6005 
   6006 /************************ Bootstrapping routines ****************************/
   6007 
   6008 #ifndef ARM_MMU_EXTENDED
   6009 static void
   6010 pmap_init_l1(struct l1_ttable *l1, pd_entry_t *l1pt)
   6011 {
   6012 	int i;
   6013 
   6014 	l1->l1_kva = l1pt;
   6015 	l1->l1_domain_use_count = 0;
   6016 	l1->l1_domain_first = 0;
   6017 
   6018 	for (i = 0; i < PMAP_DOMAINS; i++)
   6019 		l1->l1_domain_free[i] = i + 1;
   6020 
   6021 	/*
   6022 	 * Copy the kernel's L1 entries to each new L1.
   6023 	 */
   6024 	if (pmap_initialized)
   6025 		memcpy(l1pt, pmap_l1_kva(pmap_kernel()), L1_TABLE_SIZE);
   6026 
   6027 	if (pmap_extract(pmap_kernel(), (vaddr_t)l1pt,
   6028 	    &l1->l1_physaddr) == false)
   6029 		panic("pmap_init_l1: can't get PA of L1 at %p", l1pt);
   6030 
   6031 	SLIST_INSERT_HEAD(&l1_list, l1, l1_link);
   6032 	TAILQ_INSERT_TAIL(&l1_lru_list, l1, l1_lru);
   6033 }
   6034 #endif /* !ARM_MMU_EXTENDED */
   6035 
   6036 /*
   6037  * pmap_bootstrap() is called from the board-specific initarm() routine
   6038  * once the kernel L1/L2 descriptors tables have been set up.
   6039  *
   6040  * This is a somewhat convoluted process since pmap bootstrap is, effectively,
   6041  * spread over a number of disparate files/functions.
   6042  *
   6043  * We are passed the following parameters
   6044  *  - kernel_l1pt
   6045  *    This is a pointer to the base of the kernel's L1 translation table.
   6046  *  - vstart
   6047  *    1MB-aligned start of managed kernel virtual memory.
   6048  *  - vend
   6049  *    1MB-aligned end of managed kernel virtual memory.
   6050  *
   6051  * We use the first parameter to build the metadata (struct l1_ttable and
   6052  * struct l2_dtable) necessary to track kernel mappings.
   6053  */
   6054 #define	PMAP_STATIC_L2_SIZE 16
   6055 void
   6056 pmap_bootstrap(vaddr_t vstart, vaddr_t vend)
   6057 {
   6058 	static struct l2_dtable static_l2[PMAP_STATIC_L2_SIZE];
   6059 #ifndef ARM_MMU_EXTENDED
   6060 	static struct l1_ttable static_l1;
   6061 	struct l1_ttable *l1 = &static_l1;
   6062 #endif
   6063 	struct l2_dtable *l2;
   6064 	struct l2_bucket *l2b;
   6065 	pd_entry_t *l1pt = (pd_entry_t *) kernel_l1pt.pv_va;
   6066 	pmap_t pm = pmap_kernel();
   6067 	pt_entry_t *ptep;
   6068 	paddr_t pa;
   6069 	vsize_t size;
   6070 	int nptes, l2idx, l2next = 0;
   6071 
   6072 #ifdef ARM_MMU_EXTENDED
   6073 	KASSERT(pte_l1_s_cache_mode == pte_l1_s_cache_mode_pt);
   6074 	KASSERT(pte_l2_s_cache_mode == pte_l2_s_cache_mode_pt);
   6075 #endif
   6076 
   6077 #ifdef VERBOSE_INIT_ARM
   6078 	printf("kpm ");
   6079 #endif
   6080 	/*
   6081 	 * Initialise the kernel pmap object
   6082 	 */
   6083 	curcpu()->ci_pmap_cur = pm;
   6084 #ifdef ARM_MMU_EXTENDED
   6085 	pm->pm_l1 = l1pt;
   6086 	pm->pm_l1_pa = kernel_l1pt.pv_pa;
   6087 #ifdef VERBOSE_INIT_ARM
   6088 	printf("tlb0 ");
   6089 #endif
   6090 	pmap_tlb_info_init(&pmap_tlb0_info);
   6091 #ifdef MULTIPROCESSOR
   6092 #ifdef VERBOSE_INIT_ARM
   6093 	printf("kcpusets ");
   6094 #endif
   6095 	pm->pm_onproc = kcpuset_running;
   6096 	pm->pm_active = kcpuset_running;
   6097 #endif
   6098 #else
   6099 	pm->pm_l1 = l1;
   6100 #endif
   6101 
   6102 #ifdef VERBOSE_INIT_ARM
   6103 	printf("locks ");
   6104 #endif
   6105 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   6106 	if (arm_cache_prefer_mask != 0) {
   6107 		mutex_init(&pmap_lock, MUTEX_DEFAULT, IPL_VM);
   6108 	} else {
   6109 #endif
   6110 		mutex_init(&pmap_lock, MUTEX_DEFAULT, IPL_NONE);
   6111 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   6112 	}
   6113 #endif
   6114 	mutex_init(&pm->pm_obj_lock, MUTEX_DEFAULT, IPL_NONE);
   6115 	uvm_obj_init(&pm->pm_obj, NULL, false, 1);
   6116 	uvm_obj_setlock(&pm->pm_obj, &pm->pm_obj_lock);
   6117 
   6118 #ifdef VERBOSE_INIT_ARM
   6119 	printf("l1pt ");
   6120 #endif
   6121 	/*
   6122 	 * Scan the L1 translation table created by initarm() and create
   6123 	 * the required metadata for all valid mappings found in it.
   6124 	 */
   6125 	for (size_t l1slot = 0;
   6126 	     l1slot < L1_TABLE_SIZE / sizeof(pd_entry_t);
   6127 	     l1slot++) {
   6128 		pd_entry_t pde = l1pt[l1slot];
   6129 
   6130 		/*
   6131 		 * We're only interested in Coarse mappings.
   6132 		 * pmap_extract() can deal with section mappings without
   6133 		 * recourse to checking L2 metadata.
   6134 		 */
   6135 		if ((pde & L1_TYPE_MASK) != L1_TYPE_C)
   6136 			continue;
   6137 
   6138 		/*
   6139 		 * Lookup the KVA of this L2 descriptor table
   6140 		 */
   6141 		pa = l1pte_pa(pde);
   6142 		ptep = (pt_entry_t *)kernel_pt_lookup(pa);
   6143 		if (ptep == NULL) {
   6144 			panic("pmap_bootstrap: No L2 for va 0x%x, pa 0x%lx",
   6145 			    (u_int)l1slot << L1_S_SHIFT, pa);
   6146 		}
   6147 
   6148 		/*
   6149 		 * Fetch the associated L2 metadata structure.
   6150 		 * Allocate a new one if necessary.
   6151 		 */
   6152 		if ((l2 = pm->pm_l2[L2_IDX(l1slot)]) == NULL) {
   6153 			if (l2next == PMAP_STATIC_L2_SIZE)
   6154 				panic("pmap_bootstrap: out of static L2s");
   6155 			pm->pm_l2[L2_IDX(l1slot)] = l2 = &static_l2[l2next++];
   6156 		}
   6157 
   6158 		/*
   6159 		 * One more L1 slot tracked...
   6160 		 */
   6161 		l2->l2_occupancy++;
   6162 
   6163 		/*
   6164 		 * Fill in the details of the L2 descriptor in the
   6165 		 * appropriate bucket.
   6166 		 */
   6167 		l2b = &l2->l2_bucket[L2_BUCKET(l1slot)];
   6168 		l2b->l2b_kva = ptep;
   6169 		l2b->l2b_pa = pa;
   6170 		l2b->l2b_l1slot = l1slot;
   6171 
   6172 		/*
   6173 		 * Establish an initial occupancy count for this descriptor
   6174 		 */
   6175 		for (l2idx = 0;
   6176 		    l2idx < (L2_TABLE_SIZE_REAL / sizeof(pt_entry_t));
   6177 		    l2idx++) {
   6178 			if ((ptep[l2idx] & L2_TYPE_MASK) != L2_TYPE_INV) {
   6179 				l2b->l2b_occupancy++;
   6180 			}
   6181 		}
   6182 
   6183 		/*
   6184 		 * Make sure the descriptor itself has the correct cache mode.
   6185 		 * If not, fix it, but whine about the problem. Port-meisters
   6186 		 * should consider this a clue to fix up their initarm()
   6187 		 * function. :)
   6188 		 */
   6189 		if (pmap_set_pt_cache_mode(l1pt, (vaddr_t)ptep, 1)) {
   6190 			printf("pmap_bootstrap: WARNING! wrong cache mode for "
   6191 			    "L2 pte @ %p\n", ptep);
   6192 		}
   6193 	}
   6194 
   6195 #ifdef VERBOSE_INIT_ARM
   6196 	printf("cache(l1pt) ");
   6197 #endif
   6198 	/*
   6199 	 * Ensure the primary (kernel) L1 has the correct cache mode for
   6200 	 * a page table. Bitch if it is not correctly set.
   6201 	 */
   6202 	if (pmap_set_pt_cache_mode(l1pt, kernel_l1pt.pv_va,
   6203 		    L1_TABLE_SIZE / L2_S_SIZE)) {
   6204 		printf("pmap_bootstrap: WARNING! wrong cache mode for "
   6205 		    "primary L1 @ 0x%lx\n", kernel_l1pt.pv_va);
   6206 	}
   6207 
   6208 #ifdef PMAP_CACHE_VIVT
   6209 	cpu_dcache_wbinv_all();
   6210 	cpu_tlb_flushID();
   6211 	cpu_cpwait();
   6212 #endif
   6213 
   6214 	/*
   6215 	 * now we allocate the "special" VAs which are used for tmp mappings
   6216 	 * by the pmap (and other modules).  we allocate the VAs by advancing
   6217 	 * virtual_avail (note that there are no pages mapped at these VAs).
   6218 	 *
   6219 	 * Managed KVM space start from wherever initarm() tells us.
   6220 	 */
   6221 	virtual_avail = vstart;
   6222 	virtual_end = vend;
   6223 
   6224 #ifdef VERBOSE_INIT_ARM
   6225 	printf("specials ");
   6226 #endif
   6227 #ifdef PMAP_CACHE_VIPT
   6228 	/*
   6229 	 * If we have a VIPT cache, we need one page/pte per possible alias
   6230 	 * page so we won't violate cache aliasing rules.
   6231 	 */
   6232 	virtual_avail = (virtual_avail + arm_cache_prefer_mask) & ~arm_cache_prefer_mask;
   6233 	nptes = (arm_cache_prefer_mask >> L2_S_SHIFT) + 1;
   6234 	nptes = roundup(nptes, PAGE_SIZE / L2_S_SIZE);
   6235 	if (arm_pcache.icache_type != CACHE_TYPE_PIPT
   6236 	    && arm_pcache.icache_way_size > nptes * L2_S_SIZE) {
   6237 		nptes = arm_pcache.icache_way_size >> L2_S_SHIFT;
   6238 		nptes = roundup(nptes, PAGE_SIZE / L2_S_SIZE);
   6239 	}
   6240 #else
   6241 	nptes = PAGE_SIZE / L2_S_SIZE;
   6242 #endif
   6243 #ifdef MULTIPROCESSOR
   6244 	cnptes = nptes;
   6245 	nptes *= arm_cpu_max;
   6246 #endif
   6247 	pmap_alloc_specials(&virtual_avail, nptes, &csrcp, &csrc_pte);
   6248 	pmap_set_pt_cache_mode(l1pt, (vaddr_t)csrc_pte, nptes);
   6249 	pmap_alloc_specials(&virtual_avail, nptes, &cdstp, &cdst_pte);
   6250 	pmap_set_pt_cache_mode(l1pt, (vaddr_t)cdst_pte, nptes);
   6251 	pmap_alloc_specials(&virtual_avail, nptes, &memhook, NULL);
   6252 	if (msgbufaddr == NULL) {
   6253 		pmap_alloc_specials(&virtual_avail,
   6254 		    round_page(MSGBUFSIZE) / PAGE_SIZE,
   6255 		    (void *)&msgbufaddr, NULL);
   6256 	}
   6257 
   6258 	/*
   6259 	 * Allocate a range of kernel virtual address space to be used
   6260 	 * for L2 descriptor tables and metadata allocation in
   6261 	 * pmap_growkernel().
   6262 	 */
   6263 	size = ((virtual_end - pmap_curmaxkvaddr) + L1_S_OFFSET) / L1_S_SIZE;
   6264 	pmap_alloc_specials(&virtual_avail,
   6265 	    round_page(size * L2_TABLE_SIZE_REAL) / PAGE_SIZE,
   6266 	    &pmap_kernel_l2ptp_kva, NULL);
   6267 
   6268 	size = (size + (L2_BUCKET_SIZE - 1)) / L2_BUCKET_SIZE;
   6269 	pmap_alloc_specials(&virtual_avail,
   6270 	    round_page(size * sizeof(struct l2_dtable)) / PAGE_SIZE,
   6271 	    &pmap_kernel_l2dtable_kva, NULL);
   6272 
   6273 #ifndef ARM_MMU_EXTENDED
   6274 	/*
   6275 	 * init the static-global locks and global pmap list.
   6276 	 */
   6277 	mutex_init(&l1_lru_lock, MUTEX_DEFAULT, IPL_VM);
   6278 
   6279 	/*
   6280 	 * We can now initialise the first L1's metadata.
   6281 	 */
   6282 	SLIST_INIT(&l1_list);
   6283 	TAILQ_INIT(&l1_lru_list);
   6284 	pmap_init_l1(l1, l1pt);
   6285 #endif /* ARM_MMU_EXTENDED */
   6286 
   6287 #ifndef ARM_HAS_VBAR
   6288 	/* Set up vector page L1 details, if necessary */
   6289 	if (vector_page < KERNEL_BASE) {
   6290 		pm->pm_pl1vec = pmap_l1_kva(pm) + l1pte_index(vector_page);
   6291 		l2b = pmap_get_l2_bucket(pm, vector_page);
   6292 		KDASSERT(l2b != NULL);
   6293 		pm->pm_l1vec = l2b->l2b_pa | L1_C_PROTO |
   6294 		    L1_C_DOM(pmap_domain(pm));
   6295 	} else
   6296 		pm->pm_pl1vec = NULL;
   6297 #endif
   6298 
   6299 #ifdef VERBOSE_INIT_ARM
   6300 	printf("pools ");
   6301 #endif
   6302 	/*
   6303 	 * Initialize the pmap cache
   6304 	 */
   6305 	pool_cache_bootstrap(&pmap_cache, sizeof(struct pmap), 0, 0, 0,
   6306 	    "pmappl", NULL, IPL_NONE, pmap_pmap_ctor, NULL, NULL);
   6307 
   6308 	/*
   6309 	 * Initialize the pv pool.
   6310 	 */
   6311 	pool_init(&pmap_pv_pool, sizeof(struct pv_entry), 0, 0, 0, "pvepl",
   6312 	    &pmap_bootstrap_pv_allocator, IPL_NONE);
   6313 
   6314 	/*
   6315 	 * Initialize the L2 dtable pool and cache.
   6316 	 */
   6317 	pool_cache_bootstrap(&pmap_l2dtable_cache, sizeof(struct l2_dtable), 0,
   6318 	    0, 0, "l2dtblpl", NULL, IPL_NONE, pmap_l2dtable_ctor, NULL, NULL);
   6319 
   6320 	/*
   6321 	 * Initialise the L2 descriptor table pool and cache
   6322 	 */
   6323 	pool_cache_bootstrap(&pmap_l2ptp_cache, L2_TABLE_SIZE_REAL, 0,
   6324 	    L2_TABLE_SIZE_REAL, 0, "l2ptppl", NULL, IPL_NONE,
   6325 	    pmap_l2ptp_ctor, NULL, NULL);
   6326 
   6327 	mutex_init(&memlock, MUTEX_DEFAULT, IPL_NONE);
   6328 
   6329 	cpu_dcache_wbinv_all();
   6330 }
   6331 
   6332 static bool
   6333 pmap_set_pt_cache_mode(pd_entry_t *kl1, vaddr_t va, size_t nptes)
   6334 {
   6335 #ifdef ARM_MMU_EXTENDED
   6336 	return false;
   6337 #else
   6338 	if (pte_l1_s_cache_mode == pte_l1_s_cache_mode_pt
   6339 	    && pte_l2_s_cache_mode == pte_l2_s_cache_mode_pt)
   6340 		return false;
   6341 
   6342 	const vaddr_t eva = va + nptes * PAGE_SIZE;
   6343 	int rv = 0;
   6344 
   6345 	while (va < eva) {
   6346 		/*
   6347 		 * Make sure the descriptor itself has the correct cache mode
   6348 		 */
   6349 		pd_entry_t * const pdep = &kl1[l1pte_index(va)];
   6350 		pd_entry_t pde = *pdep;
   6351 
   6352 		if (l1pte_section_p(pde)) {
   6353 			__CTASSERT((L1_S_CACHE_MASK & L1_S_V6_SUPER) == 0);
   6354 			if ((pde & L1_S_CACHE_MASK) != pte_l1_s_cache_mode_pt) {
   6355 				*pdep = (pde & ~L1_S_CACHE_MASK) |
   6356 				    pte_l1_s_cache_mode_pt;
   6357 				PDE_SYNC(pdep);
   6358 				cpu_dcache_wbinv_range((vaddr_t)pdep,
   6359 				    sizeof(*pdep));
   6360 				rv = 1;
   6361 			}
   6362 			return rv;
   6363 		}
   6364 		vaddr_t pa = l1pte_pa(pde);
   6365 		pt_entry_t *ptep = (pt_entry_t *)kernel_pt_lookup(pa);
   6366 		if (ptep == NULL)
   6367 			panic("pmap_bootstrap: No PTP for va %#lx\n", va);
   6368 
   6369 		ptep += l2pte_index(va);
   6370 		const pt_entry_t opte = *ptep;
   6371 		if ((opte & L2_S_CACHE_MASK) != pte_l2_s_cache_mode_pt) {
   6372 			const pt_entry_t npte = (opte & ~L2_S_CACHE_MASK)
   6373 			    | pte_l2_s_cache_mode_pt;
   6374 			l2pte_set(ptep, npte, opte);
   6375 			PTE_SYNC(ptep);
   6376 			cpu_dcache_wbinv_range((vaddr_t)ptep, sizeof(*ptep));
   6377 			rv = 1;
   6378 		}
   6379 		va += PAGE_SIZE;
   6380 	}
   6381 
   6382 	return (rv);
   6383 #endif
   6384 }
   6385 
   6386 static void
   6387 pmap_alloc_specials(vaddr_t *availp, int pages, vaddr_t *vap, pt_entry_t **ptep)
   6388 {
   6389 	vaddr_t va = *availp;
   6390 	struct l2_bucket *l2b;
   6391 
   6392 	if (ptep) {
   6393 		l2b = pmap_get_l2_bucket(pmap_kernel(), va);
   6394 		if (l2b == NULL)
   6395 			panic("pmap_alloc_specials: no l2b for 0x%lx", va);
   6396 
   6397 		if (ptep)
   6398 			*ptep = &l2b->l2b_kva[l2pte_index(va)];
   6399 	}
   6400 
   6401 	*vap = va;
   6402 	*availp = va + (PAGE_SIZE * pages);
   6403 }
   6404 
   6405 void
   6406 pmap_init(void)
   6407 {
   6408 
   6409 	/*
   6410 	 * Set the available memory vars - These do not map to real memory
   6411 	 * addresses and cannot as the physical memory is fragmented.
   6412 	 * They are used by ps for %mem calculations.
   6413 	 * One could argue whether this should be the entire memory or just
   6414 	 * the memory that is useable in a user process.
   6415 	 */
   6416 	avail_start = ptoa(VM_PHYSMEM_PTR(0)->start);
   6417 	avail_end = ptoa(VM_PHYSMEM_PTR(vm_nphysseg - 1)->end);
   6418 
   6419 	/*
   6420 	 * Now we need to free enough pv_entry structures to allow us to get
   6421 	 * the kmem_map/kmem_object allocated and inited (done after this
   6422 	 * function is finished).  to do this we allocate one bootstrap page out
   6423 	 * of kernel_map and use it to provide an initial pool of pv_entry
   6424 	 * structures.   we never free this page.
   6425 	 */
   6426 	pool_setlowat(&pmap_pv_pool, (PAGE_SIZE / sizeof(struct pv_entry)) * 2);
   6427 
   6428 #ifdef ARM_MMU_EXTENDED
   6429 	pmap_tlb_info_evcnt_attach(&pmap_tlb0_info);
   6430 #endif
   6431 
   6432 	pmap_initialized = true;
   6433 }
   6434 
   6435 static vaddr_t last_bootstrap_page = 0;
   6436 static void *free_bootstrap_pages = NULL;
   6437 
   6438 static void *
   6439 pmap_bootstrap_pv_page_alloc(struct pool *pp, int flags)
   6440 {
   6441 	extern void *pool_page_alloc(struct pool *, int);
   6442 	vaddr_t new_page;
   6443 	void *rv;
   6444 
   6445 	if (pmap_initialized)
   6446 		return (pool_page_alloc(pp, flags));
   6447 
   6448 	if (free_bootstrap_pages) {
   6449 		rv = free_bootstrap_pages;
   6450 		free_bootstrap_pages = *((void **)rv);
   6451 		return (rv);
   6452 	}
   6453 
   6454 	KASSERT(kernel_map != NULL);
   6455 	new_page = uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
   6456 	    UVM_KMF_WIRED | ((flags & PR_WAITOK) ? 0 : UVM_KMF_NOWAIT));
   6457 
   6458 	KASSERT(new_page > last_bootstrap_page);
   6459 	last_bootstrap_page = new_page;
   6460 	return ((void *)new_page);
   6461 }
   6462 
   6463 static void
   6464 pmap_bootstrap_pv_page_free(struct pool *pp, void *v)
   6465 {
   6466 	extern void pool_page_free(struct pool *, void *);
   6467 
   6468 	if ((vaddr_t)v <= last_bootstrap_page) {
   6469 		*((void **)v) = free_bootstrap_pages;
   6470 		free_bootstrap_pages = v;
   6471 		return;
   6472 	}
   6473 
   6474 	if (pmap_initialized) {
   6475 		pool_page_free(pp, v);
   6476 		return;
   6477 	}
   6478 }
   6479 
   6480 /*
   6481  * pmap_postinit()
   6482  *
   6483  * This routine is called after the vm and kmem subsystems have been
   6484  * initialised. This allows the pmap code to perform any initialisation
   6485  * that can only be done one the memory allocation is in place.
   6486  */
   6487 void
   6488 pmap_postinit(void)
   6489 {
   6490 #ifndef ARM_MMU_EXTENDED
   6491 	extern paddr_t physical_start, physical_end;
   6492 	struct l1_ttable *l1;
   6493 	struct pglist plist;
   6494 	struct vm_page *m;
   6495 	pd_entry_t *pdep;
   6496 	vaddr_t va, eva;
   6497 	u_int loop, needed;
   6498 	int error;
   6499 #endif
   6500 
   6501 	pool_cache_setlowat(&pmap_l2ptp_cache, (PAGE_SIZE / L2_TABLE_SIZE_REAL) * 4);
   6502 	pool_cache_setlowat(&pmap_l2dtable_cache,
   6503 	    (PAGE_SIZE / sizeof(struct l2_dtable)) * 2);
   6504 
   6505 #ifndef ARM_MMU_EXTENDED
   6506 	needed = (maxproc / PMAP_DOMAINS) + ((maxproc % PMAP_DOMAINS) ? 1 : 0);
   6507 	needed -= 1;
   6508 
   6509 	l1 = kmem_alloc(sizeof(*l1) * needed, KM_SLEEP);
   6510 
   6511 	for (loop = 0; loop < needed; loop++, l1++) {
   6512 		/* Allocate a L1 page table */
   6513 		va = uvm_km_alloc(kernel_map, L1_TABLE_SIZE, 0, UVM_KMF_VAONLY);
   6514 		if (va == 0)
   6515 			panic("Cannot allocate L1 KVM");
   6516 
   6517 		error = uvm_pglistalloc(L1_TABLE_SIZE, physical_start,
   6518 		    physical_end, L1_TABLE_SIZE, 0, &plist, 1, 1);
   6519 		if (error)
   6520 			panic("Cannot allocate L1 physical pages");
   6521 
   6522 		m = TAILQ_FIRST(&plist);
   6523 		eva = va + L1_TABLE_SIZE;
   6524 		pdep = (pd_entry_t *)va;
   6525 
   6526 		while (m && va < eva) {
   6527 			paddr_t pa = VM_PAGE_TO_PHYS(m);
   6528 
   6529 			pmap_kenter_pa(va, pa,
   6530 			    VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE|PMAP_PTE);
   6531 
   6532 			va += PAGE_SIZE;
   6533 			m = TAILQ_NEXT(m, pageq.queue);
   6534 		}
   6535 
   6536 #ifdef DIAGNOSTIC
   6537 		if (m)
   6538 			panic("pmap_alloc_l1pt: pglist not empty");
   6539 #endif	/* DIAGNOSTIC */
   6540 
   6541 		pmap_init_l1(l1, pdep);
   6542 	}
   6543 
   6544 #ifdef DEBUG
   6545 	printf("pmap_postinit: Allocated %d static L1 descriptor tables\n",
   6546 	    needed);
   6547 #endif
   6548 #endif /* !ARM_MMU_EXTENDED */
   6549 }
   6550 
   6551 /*
   6552  * Note that the following routines are used by board-specific initialisation
   6553  * code to configure the initial kernel page tables.
   6554  *
   6555  * If ARM32_NEW_VM_LAYOUT is *not* defined, they operate on the assumption that
   6556  * L2 page-table pages are 4KB in size and use 4 L1 slots. This mimics the
   6557  * behaviour of the old pmap, and provides an easy migration path for
   6558  * initial bring-up of the new pmap on existing ports. Fortunately,
   6559  * pmap_bootstrap() compensates for this hackery. This is only a stop-gap and
   6560  * will be deprecated.
   6561  *
   6562  * If ARM32_NEW_VM_LAYOUT *is* defined, these functions deal with 1KB L2 page
   6563  * tables.
   6564  */
   6565 
   6566 /*
   6567  * This list exists for the benefit of pmap_map_chunk().  It keeps track
   6568  * of the kernel L2 tables during bootstrap, so that pmap_map_chunk() can
   6569  * find them as necessary.
   6570  *
   6571  * Note that the data on this list MUST remain valid after initarm() returns,
   6572  * as pmap_bootstrap() uses it to contruct L2 table metadata.
   6573  */
   6574 SLIST_HEAD(, pv_addr) kernel_pt_list = SLIST_HEAD_INITIALIZER(kernel_pt_list);
   6575 
   6576 static vaddr_t
   6577 kernel_pt_lookup(paddr_t pa)
   6578 {
   6579 	pv_addr_t *pv;
   6580 
   6581 	SLIST_FOREACH(pv, &kernel_pt_list, pv_list) {
   6582 		if (pv->pv_pa == (pa & ~PGOFSET))
   6583 			return (pv->pv_va | (pa & PGOFSET));
   6584 	}
   6585 	return (0);
   6586 }
   6587 
   6588 /*
   6589  * pmap_map_section:
   6590  *
   6591  *	Create a single section mapping.
   6592  */
   6593 void
   6594 pmap_map_section(vaddr_t l1pt, vaddr_t va, paddr_t pa, int prot, int cache)
   6595 {
   6596 	pd_entry_t * const pdep = (pd_entry_t *) l1pt;
   6597 	const size_t l1slot = l1pte_index(va);
   6598 	pd_entry_t fl;
   6599 
   6600 	KASSERT(((va | pa) & L1_S_OFFSET) == 0);
   6601 
   6602 	switch (cache) {
   6603 	case PTE_NOCACHE:
   6604 	default:
   6605 		fl = 0;
   6606 		break;
   6607 
   6608 	case PTE_CACHE:
   6609 		fl = pte_l1_s_cache_mode;
   6610 		break;
   6611 
   6612 	case PTE_PAGETABLE:
   6613 		fl = pte_l1_s_cache_mode_pt;
   6614 		break;
   6615 	}
   6616 
   6617 	const pd_entry_t npde = L1_S_PROTO | pa |
   6618 	    L1_S_PROT(PTE_KERNEL, prot) | fl | L1_S_DOM(PMAP_DOMAIN_KERNEL);
   6619 	l1pte_setone(pdep + l1slot, npde);
   6620 	PDE_SYNC(pdep + l1slot);
   6621 }
   6622 
   6623 /*
   6624  * pmap_map_entry:
   6625  *
   6626  *	Create a single page mapping.
   6627  */
   6628 void
   6629 pmap_map_entry(vaddr_t l1pt, vaddr_t va, paddr_t pa, int prot, int cache)
   6630 {
   6631 	pd_entry_t * const pdep = (pd_entry_t *) l1pt;
   6632 	const size_t l1slot = l1pte_index(va);
   6633 	pt_entry_t npte;
   6634 	pt_entry_t *ptep;
   6635 
   6636 	KASSERT(((va | pa) & PGOFSET) == 0);
   6637 
   6638 	switch (cache) {
   6639 	case PTE_NOCACHE:
   6640 	default:
   6641 		npte = 0;
   6642 		break;
   6643 
   6644 	case PTE_CACHE:
   6645 		npte = pte_l2_s_cache_mode;
   6646 		break;
   6647 
   6648 	case PTE_PAGETABLE:
   6649 		npte = pte_l2_s_cache_mode_pt;
   6650 		break;
   6651 	}
   6652 
   6653 	if ((pdep[l1slot] & L1_TYPE_MASK) != L1_TYPE_C)
   6654 		panic("pmap_map_entry: no L2 table for VA 0x%08lx", va);
   6655 
   6656 	ptep = (pt_entry_t *) kernel_pt_lookup(l1pte_pa(pdep[l1slot]));
   6657 	if (ptep == NULL)
   6658 		panic("pmap_map_entry: can't find L2 table for VA 0x%08lx", va);
   6659 
   6660 	npte |= L2_S_PROTO | pa | L2_S_PROT(PTE_KERNEL, prot);
   6661 #ifdef ARM_MMU_EXTENDED
   6662 	if (prot & VM_PROT_EXECUTE) {
   6663 		npte &= ~L2_XS_XN;
   6664 	}
   6665 #endif
   6666 	ptep += l2pte_index(va);
   6667 	l2pte_set(ptep, npte, 0);
   6668 	PTE_SYNC(ptep);
   6669 }
   6670 
   6671 /*
   6672  * pmap_link_l2pt:
   6673  *
   6674  *	Link the L2 page table specified by "l2pv" into the L1
   6675  *	page table at the slot for "va".
   6676  */
   6677 void
   6678 pmap_link_l2pt(vaddr_t l1pt, vaddr_t va, pv_addr_t *l2pv)
   6679 {
   6680 	pd_entry_t * const pdep = (pd_entry_t *) l1pt + l1pte_index(va);
   6681 
   6682 	KASSERT((va & ((L1_S_SIZE * (PAGE_SIZE / L2_T_SIZE)) - 1)) == 0);
   6683 	KASSERT((l2pv->pv_pa & PGOFSET) == 0);
   6684 
   6685 	const pd_entry_t npde = L1_S_DOM(PMAP_DOMAIN_KERNEL) | L1_C_PROTO
   6686 	    | l2pv->pv_pa;
   6687 
   6688 	l1pte_set(pdep, npde);
   6689 	PDE_SYNC_RANGE(pdep, PAGE_SIZE / L2_T_SIZE);
   6690 
   6691 	SLIST_INSERT_HEAD(&kernel_pt_list, l2pv, pv_list);
   6692 }
   6693 
   6694 /*
   6695  * pmap_map_chunk:
   6696  *
   6697  *	Map a chunk of memory using the most efficient mappings
   6698  *	possible (section, large page, small page) into the
   6699  *	provided L1 and L2 tables at the specified virtual address.
   6700  */
   6701 vsize_t
   6702 pmap_map_chunk(vaddr_t l1pt, vaddr_t va, paddr_t pa, vsize_t size,
   6703     int prot, int cache)
   6704 {
   6705 	pd_entry_t * const pdep = (pd_entry_t *) l1pt;
   6706 	pt_entry_t f1, f2s, f2l;
   6707 	vsize_t resid;
   6708 
   6709 	resid = (size + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
   6710 
   6711 	if (l1pt == 0)
   6712 		panic("pmap_map_chunk: no L1 table provided");
   6713 
   6714 #ifdef VERBOSE_INIT_ARM
   6715 	printf("pmap_map_chunk: pa=0x%lx va=0x%lx size=0x%lx resid=0x%lx "
   6716 	    "prot=0x%x cache=%d\n", pa, va, size, resid, prot, cache);
   6717 #endif
   6718 
   6719 	switch (cache) {
   6720 	case PTE_NOCACHE:
   6721 	default:
   6722 		f1 = 0;
   6723 		f2l = 0;
   6724 		f2s = 0;
   6725 		break;
   6726 
   6727 	case PTE_CACHE:
   6728 		f1 = pte_l1_s_cache_mode;
   6729 		f2l = pte_l2_l_cache_mode;
   6730 		f2s = pte_l2_s_cache_mode;
   6731 		break;
   6732 
   6733 	case PTE_PAGETABLE:
   6734 		f1 = pte_l1_s_cache_mode_pt;
   6735 		f2l = pte_l2_l_cache_mode_pt;
   6736 		f2s = pte_l2_s_cache_mode_pt;
   6737 		break;
   6738 	}
   6739 
   6740 	size = resid;
   6741 
   6742 	while (resid > 0) {
   6743 		const size_t l1slot = l1pte_index(va);
   6744 #if (ARM_MMU_V6 + ARM_MMU_V7) > 0
   6745 		/* See if we can use a supersection mapping. */
   6746 		if (L1_SS_PROTO && L1_SS_MAPPABLE_P(va, pa, resid)) {
   6747 			/* Supersection are always domain 0 */
   6748 			const pd_entry_t npde = L1_SS_PROTO | pa
   6749 #ifdef ARM_MMU_EXTENDED
   6750 			    | ((prot & VM_PROT_EXECUTE) ? 0 : L1_S_V6_XN)
   6751 			    | (va & 0x80000000 ? 0 : L1_S_V6_nG)
   6752 #endif
   6753 			    | L1_S_PROT(PTE_KERNEL, prot) | f1;
   6754 #ifdef VERBOSE_INIT_ARM
   6755 			printf("sS");
   6756 #endif
   6757 			l1pte_set(&pdep[l1slot], npde);
   6758 			PDE_SYNC_RANGE(&pdep[l1slot], L1_SS_SIZE / L1_S_SIZE);
   6759 			va += L1_SS_SIZE;
   6760 			pa += L1_SS_SIZE;
   6761 			resid -= L1_SS_SIZE;
   6762 			continue;
   6763 		}
   6764 #endif
   6765 		/* See if we can use a section mapping. */
   6766 		if (L1_S_MAPPABLE_P(va, pa, resid)) {
   6767 			const pd_entry_t npde = L1_S_PROTO | pa
   6768 #ifdef ARM_MMU_EXTENDED
   6769 			    | ((prot & VM_PROT_EXECUTE) ? 0 : L1_S_V6_XN)
   6770 			    | (va & 0x80000000 ? 0 : L1_S_V6_nG)
   6771 #endif
   6772 			    | L1_S_PROT(PTE_KERNEL, prot) | f1
   6773 			    | L1_S_DOM(PMAP_DOMAIN_KERNEL);
   6774 #ifdef VERBOSE_INIT_ARM
   6775 			printf("S");
   6776 #endif
   6777 			l1pte_set(&pdep[l1slot], npde);
   6778 			PDE_SYNC(&pdep[l1slot]);
   6779 			va += L1_S_SIZE;
   6780 			pa += L1_S_SIZE;
   6781 			resid -= L1_S_SIZE;
   6782 			continue;
   6783 		}
   6784 
   6785 		/*
   6786 		 * Ok, we're going to use an L2 table.  Make sure
   6787 		 * one is actually in the corresponding L1 slot
   6788 		 * for the current VA.
   6789 		 */
   6790 		if ((pdep[l1slot] & L1_TYPE_MASK) != L1_TYPE_C)
   6791 			panic("%s: no L2 table for VA %#lx", __func__, va);
   6792 
   6793 		pt_entry_t *ptep = (pt_entry_t *) kernel_pt_lookup(l1pte_pa(pdep[l1slot]));
   6794 		if (ptep == NULL)
   6795 			panic("%s: can't find L2 table for VA %#lx", __func__,
   6796 			    va);
   6797 
   6798 		ptep += l2pte_index(va);
   6799 
   6800 		/* See if we can use a L2 large page mapping. */
   6801 		if (L2_L_MAPPABLE_P(va, pa, resid)) {
   6802 			const pt_entry_t npte = L2_L_PROTO | pa
   6803 #ifdef ARM_MMU_EXTENDED
   6804 			    | ((prot & VM_PROT_EXECUTE) ? 0 : L2_XS_L_XN)
   6805 			    | (va & 0x80000000 ? 0 : L2_XS_nG)
   6806 #endif
   6807 			    | L2_L_PROT(PTE_KERNEL, prot) | f2l;
   6808 #ifdef VERBOSE_INIT_ARM
   6809 			printf("L");
   6810 #endif
   6811 			l2pte_set(ptep, npte, 0);
   6812 			PTE_SYNC_RANGE(ptep, L2_L_SIZE / L2_S_SIZE);
   6813 			va += L2_L_SIZE;
   6814 			pa += L2_L_SIZE;
   6815 			resid -= L2_L_SIZE;
   6816 			continue;
   6817 		}
   6818 
   6819 #ifdef VERBOSE_INIT_ARM
   6820 		printf("P");
   6821 #endif
   6822 		/* Use a small page mapping. */
   6823 		pt_entry_t npte = L2_S_PROTO | pa
   6824 #ifdef ARM_MMU_EXTENDED
   6825 		    | ((prot & VM_PROT_EXECUTE) ? 0 : L2_XS_XN)
   6826 		    | (va & 0x80000000 ? 0 : L2_XS_nG)
   6827 #endif
   6828 		    | L2_S_PROT(PTE_KERNEL, prot) | f2s;
   6829 #ifdef ARM_MMU_EXTENDED
   6830 		npte &= ((prot & VM_PROT_EXECUTE) ? ~L2_XS_XN : ~0);
   6831 #endif
   6832 		l2pte_set(ptep, npte, 0);
   6833 		PTE_SYNC(ptep);
   6834 		va += PAGE_SIZE;
   6835 		pa += PAGE_SIZE;
   6836 		resid -= PAGE_SIZE;
   6837 	}
   6838 #ifdef VERBOSE_INIT_ARM
   6839 	printf("\n");
   6840 #endif
   6841 	return (size);
   6842 }
   6843 
   6844 /********************** Static device map routines ***************************/
   6845 
   6846 static const struct pmap_devmap *pmap_devmap_table;
   6847 
   6848 /*
   6849  * Register the devmap table.  This is provided in case early console
   6850  * initialization needs to register mappings created by bootstrap code
   6851  * before pmap_devmap_bootstrap() is called.
   6852  */
   6853 void
   6854 pmap_devmap_register(const struct pmap_devmap *table)
   6855 {
   6856 
   6857 	pmap_devmap_table = table;
   6858 }
   6859 
   6860 /*
   6861  * Map all of the static regions in the devmap table, and remember
   6862  * the devmap table so other parts of the kernel can look up entries
   6863  * later.
   6864  */
   6865 void
   6866 pmap_devmap_bootstrap(vaddr_t l1pt, const struct pmap_devmap *table)
   6867 {
   6868 	int i;
   6869 
   6870 	pmap_devmap_table = table;
   6871 
   6872 	for (i = 0; pmap_devmap_table[i].pd_size != 0; i++) {
   6873 #ifdef VERBOSE_INIT_ARM
   6874 		printf("devmap: %08lx -> %08lx @ %08lx\n",
   6875 		    pmap_devmap_table[i].pd_pa,
   6876 		    pmap_devmap_table[i].pd_pa +
   6877 			pmap_devmap_table[i].pd_size - 1,
   6878 		    pmap_devmap_table[i].pd_va);
   6879 #endif
   6880 		pmap_map_chunk(l1pt, pmap_devmap_table[i].pd_va,
   6881 		    pmap_devmap_table[i].pd_pa,
   6882 		    pmap_devmap_table[i].pd_size,
   6883 		    pmap_devmap_table[i].pd_prot,
   6884 		    pmap_devmap_table[i].pd_cache);
   6885 	}
   6886 }
   6887 
   6888 const struct pmap_devmap *
   6889 pmap_devmap_find_pa(paddr_t pa, psize_t size)
   6890 {
   6891 	uint64_t endpa;
   6892 	int i;
   6893 
   6894 	if (pmap_devmap_table == NULL)
   6895 		return (NULL);
   6896 
   6897 	endpa = (uint64_t)pa + (uint64_t)(size - 1);
   6898 
   6899 	for (i = 0; pmap_devmap_table[i].pd_size != 0; i++) {
   6900 		if (pa >= pmap_devmap_table[i].pd_pa &&
   6901 		    endpa <= (uint64_t)pmap_devmap_table[i].pd_pa +
   6902 			     (uint64_t)(pmap_devmap_table[i].pd_size - 1))
   6903 			return (&pmap_devmap_table[i]);
   6904 	}
   6905 
   6906 	return (NULL);
   6907 }
   6908 
   6909 const struct pmap_devmap *
   6910 pmap_devmap_find_va(vaddr_t va, vsize_t size)
   6911 {
   6912 	int i;
   6913 
   6914 	if (pmap_devmap_table == NULL)
   6915 		return (NULL);
   6916 
   6917 	for (i = 0; pmap_devmap_table[i].pd_size != 0; i++) {
   6918 		if (va >= pmap_devmap_table[i].pd_va &&
   6919 		    va + size - 1 <= pmap_devmap_table[i].pd_va +
   6920 				     pmap_devmap_table[i].pd_size - 1)
   6921 			return (&pmap_devmap_table[i]);
   6922 	}
   6923 
   6924 	return (NULL);
   6925 }
   6926 
   6927 /********************** PTE initialization routines **************************/
   6928 
   6929 /*
   6930  * These routines are called when the CPU type is identified to set up
   6931  * the PTE prototypes, cache modes, etc.
   6932  *
   6933  * The variables are always here, just in case modules need to reference
   6934  * them (though, they shouldn't).
   6935  */
   6936 
   6937 pt_entry_t	pte_l1_s_cache_mode;
   6938 pt_entry_t	pte_l1_s_wc_mode;
   6939 pt_entry_t	pte_l1_s_cache_mode_pt;
   6940 pt_entry_t	pte_l1_s_cache_mask;
   6941 
   6942 pt_entry_t	pte_l2_l_cache_mode;
   6943 pt_entry_t	pte_l2_l_wc_mode;
   6944 pt_entry_t	pte_l2_l_cache_mode_pt;
   6945 pt_entry_t	pte_l2_l_cache_mask;
   6946 
   6947 pt_entry_t	pte_l2_s_cache_mode;
   6948 pt_entry_t	pte_l2_s_wc_mode;
   6949 pt_entry_t	pte_l2_s_cache_mode_pt;
   6950 pt_entry_t	pte_l2_s_cache_mask;
   6951 
   6952 pt_entry_t	pte_l1_s_prot_u;
   6953 pt_entry_t	pte_l1_s_prot_w;
   6954 pt_entry_t	pte_l1_s_prot_ro;
   6955 pt_entry_t	pte_l1_s_prot_mask;
   6956 
   6957 pt_entry_t	pte_l2_s_prot_u;
   6958 pt_entry_t	pte_l2_s_prot_w;
   6959 pt_entry_t	pte_l2_s_prot_ro;
   6960 pt_entry_t	pte_l2_s_prot_mask;
   6961 
   6962 pt_entry_t	pte_l2_l_prot_u;
   6963 pt_entry_t	pte_l2_l_prot_w;
   6964 pt_entry_t	pte_l2_l_prot_ro;
   6965 pt_entry_t	pte_l2_l_prot_mask;
   6966 
   6967 pt_entry_t	pte_l1_ss_proto;
   6968 pt_entry_t	pte_l1_s_proto;
   6969 pt_entry_t	pte_l1_c_proto;
   6970 pt_entry_t	pte_l2_s_proto;
   6971 
   6972 void		(*pmap_copy_page_func)(paddr_t, paddr_t);
   6973 void		(*pmap_zero_page_func)(paddr_t);
   6974 
   6975 #if (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6 + ARM_MMU_V7) != 0
   6976 void
   6977 pmap_pte_init_generic(void)
   6978 {
   6979 
   6980 	pte_l1_s_cache_mode = L1_S_B|L1_S_C;
   6981 	pte_l1_s_wc_mode = L1_S_B;
   6982 	pte_l1_s_cache_mask = L1_S_CACHE_MASK_generic;
   6983 
   6984 	pte_l2_l_cache_mode = L2_B|L2_C;
   6985 	pte_l2_l_wc_mode = L2_B;
   6986 	pte_l2_l_cache_mask = L2_L_CACHE_MASK_generic;
   6987 
   6988 	pte_l2_s_cache_mode = L2_B|L2_C;
   6989 	pte_l2_s_wc_mode = L2_B;
   6990 	pte_l2_s_cache_mask = L2_S_CACHE_MASK_generic;
   6991 
   6992 	/*
   6993 	 * If we have a write-through cache, set B and C.  If
   6994 	 * we have a write-back cache, then we assume setting
   6995 	 * only C will make those pages write-through (except for those
   6996 	 * Cortex CPUs which can read the L1 caches).
   6997 	 */
   6998 	if (cpufuncs.cf_dcache_wb_range == (void *) cpufunc_nullop
   6999 #if ARM_MMU_V7 > 0
   7000 	    || CPU_ID_CORTEX_P(curcpu()->ci_arm_cpuid)
   7001 #endif
   7002 #if ARM_MMU_V6 > 0
   7003 	    || CPU_ID_ARM11_P(curcpu()->ci_arm_cpuid) /* arm116 errata 399234 */
   7004 #endif
   7005 	    || false) {
   7006 		pte_l1_s_cache_mode_pt = L1_S_B|L1_S_C;
   7007 		pte_l2_l_cache_mode_pt = L2_B|L2_C;
   7008 		pte_l2_s_cache_mode_pt = L2_B|L2_C;
   7009 	} else {
   7010 		pte_l1_s_cache_mode_pt = L1_S_C;	/* write through */
   7011 		pte_l2_l_cache_mode_pt = L2_C;		/* write through */
   7012 		pte_l2_s_cache_mode_pt = L2_C;		/* write through */
   7013 	}
   7014 
   7015 	pte_l1_s_prot_u = L1_S_PROT_U_generic;
   7016 	pte_l1_s_prot_w = L1_S_PROT_W_generic;
   7017 	pte_l1_s_prot_ro = L1_S_PROT_RO_generic;
   7018 	pte_l1_s_prot_mask = L1_S_PROT_MASK_generic;
   7019 
   7020 	pte_l2_s_prot_u = L2_S_PROT_U_generic;
   7021 	pte_l2_s_prot_w = L2_S_PROT_W_generic;
   7022 	pte_l2_s_prot_ro = L2_S_PROT_RO_generic;
   7023 	pte_l2_s_prot_mask = L2_S_PROT_MASK_generic;
   7024 
   7025 	pte_l2_l_prot_u = L2_L_PROT_U_generic;
   7026 	pte_l2_l_prot_w = L2_L_PROT_W_generic;
   7027 	pte_l2_l_prot_ro = L2_L_PROT_RO_generic;
   7028 	pte_l2_l_prot_mask = L2_L_PROT_MASK_generic;
   7029 
   7030 	pte_l1_ss_proto = L1_SS_PROTO_generic;
   7031 	pte_l1_s_proto = L1_S_PROTO_generic;
   7032 	pte_l1_c_proto = L1_C_PROTO_generic;
   7033 	pte_l2_s_proto = L2_S_PROTO_generic;
   7034 
   7035 	pmap_copy_page_func = pmap_copy_page_generic;
   7036 	pmap_zero_page_func = pmap_zero_page_generic;
   7037 }
   7038 
   7039 #if defined(CPU_ARM8)
   7040 void
   7041 pmap_pte_init_arm8(void)
   7042 {
   7043 
   7044 	/*
   7045 	 * ARM8 is compatible with generic, but we need to use
   7046 	 * the page tables uncached.
   7047 	 */
   7048 	pmap_pte_init_generic();
   7049 
   7050 	pte_l1_s_cache_mode_pt = 0;
   7051 	pte_l2_l_cache_mode_pt = 0;
   7052 	pte_l2_s_cache_mode_pt = 0;
   7053 }
   7054 #endif /* CPU_ARM8 */
   7055 
   7056 #if defined(CPU_ARM9) && defined(ARM9_CACHE_WRITE_THROUGH)
   7057 void
   7058 pmap_pte_init_arm9(void)
   7059 {
   7060 
   7061 	/*
   7062 	 * ARM9 is compatible with generic, but we want to use
   7063 	 * write-through caching for now.
   7064 	 */
   7065 	pmap_pte_init_generic();
   7066 
   7067 	pte_l1_s_cache_mode = L1_S_C;
   7068 	pte_l2_l_cache_mode = L2_C;
   7069 	pte_l2_s_cache_mode = L2_C;
   7070 
   7071 	pte_l1_s_wc_mode = L1_S_B;
   7072 	pte_l2_l_wc_mode = L2_B;
   7073 	pte_l2_s_wc_mode = L2_B;
   7074 
   7075 	pte_l1_s_cache_mode_pt = L1_S_C;
   7076 	pte_l2_l_cache_mode_pt = L2_C;
   7077 	pte_l2_s_cache_mode_pt = L2_C;
   7078 }
   7079 #endif /* CPU_ARM9 && ARM9_CACHE_WRITE_THROUGH */
   7080 #endif /* (ARM_MMU_GENERIC + ARM_MMU_SA1 + ARM_MMU_V6) != 0 */
   7081 
   7082 #if defined(CPU_ARM10)
   7083 void
   7084 pmap_pte_init_arm10(void)
   7085 {
   7086 
   7087 	/*
   7088 	 * ARM10 is compatible with generic, but we want to use
   7089 	 * write-through caching for now.
   7090 	 */
   7091 	pmap_pte_init_generic();
   7092 
   7093 	pte_l1_s_cache_mode = L1_S_B | L1_S_C;
   7094 	pte_l2_l_cache_mode = L2_B | L2_C;
   7095 	pte_l2_s_cache_mode = L2_B | L2_C;
   7096 
   7097 	pte_l1_s_cache_mode = L1_S_B;
   7098 	pte_l2_l_cache_mode = L2_B;
   7099 	pte_l2_s_cache_mode = L2_B;
   7100 
   7101 	pte_l1_s_cache_mode_pt = L1_S_C;
   7102 	pte_l2_l_cache_mode_pt = L2_C;
   7103 	pte_l2_s_cache_mode_pt = L2_C;
   7104 
   7105 }
   7106 #endif /* CPU_ARM10 */
   7107 
   7108 #if defined(CPU_ARM11) && defined(ARM11_CACHE_WRITE_THROUGH)
   7109 void
   7110 pmap_pte_init_arm11(void)
   7111 {
   7112 
   7113 	/*
   7114 	 * ARM11 is compatible with generic, but we want to use
   7115 	 * write-through caching for now.
   7116 	 */
   7117 	pmap_pte_init_generic();
   7118 
   7119 	pte_l1_s_cache_mode = L1_S_C;
   7120 	pte_l2_l_cache_mode = L2_C;
   7121 	pte_l2_s_cache_mode = L2_C;
   7122 
   7123 	pte_l1_s_wc_mode = L1_S_B;
   7124 	pte_l2_l_wc_mode = L2_B;
   7125 	pte_l2_s_wc_mode = L2_B;
   7126 
   7127 	pte_l1_s_cache_mode_pt = L1_S_C;
   7128 	pte_l2_l_cache_mode_pt = L2_C;
   7129 	pte_l2_s_cache_mode_pt = L2_C;
   7130 }
   7131 #endif /* CPU_ARM11 && ARM11_CACHE_WRITE_THROUGH */
   7132 
   7133 #if ARM_MMU_SA1 == 1
   7134 void
   7135 pmap_pte_init_sa1(void)
   7136 {
   7137 
   7138 	/*
   7139 	 * The StrongARM SA-1 cache does not have a write-through
   7140 	 * mode.  So, do the generic initialization, then reset
   7141 	 * the page table cache mode to B=1,C=1, and note that
   7142 	 * the PTEs need to be sync'd.
   7143 	 */
   7144 	pmap_pte_init_generic();
   7145 
   7146 	pte_l1_s_cache_mode_pt = L1_S_B|L1_S_C;
   7147 	pte_l2_l_cache_mode_pt = L2_B|L2_C;
   7148 	pte_l2_s_cache_mode_pt = L2_B|L2_C;
   7149 
   7150 	pmap_needs_pte_sync = 1;
   7151 }
   7152 #endif /* ARM_MMU_SA1 == 1*/
   7153 
   7154 #if ARM_MMU_XSCALE == 1
   7155 #if (ARM_NMMUS > 1)
   7156 static u_int xscale_use_minidata;
   7157 #endif
   7158 
   7159 void
   7160 pmap_pte_init_xscale(void)
   7161 {
   7162 	uint32_t auxctl;
   7163 	int write_through = 0;
   7164 
   7165 	pte_l1_s_cache_mode = L1_S_B|L1_S_C;
   7166 	pte_l1_s_wc_mode = L1_S_B;
   7167 	pte_l1_s_cache_mask = L1_S_CACHE_MASK_xscale;
   7168 
   7169 	pte_l2_l_cache_mode = L2_B|L2_C;
   7170 	pte_l2_l_wc_mode = L2_B;
   7171 	pte_l2_l_cache_mask = L2_L_CACHE_MASK_xscale;
   7172 
   7173 	pte_l2_s_cache_mode = L2_B|L2_C;
   7174 	pte_l2_s_wc_mode = L2_B;
   7175 	pte_l2_s_cache_mask = L2_S_CACHE_MASK_xscale;
   7176 
   7177 	pte_l1_s_cache_mode_pt = L1_S_C;
   7178 	pte_l2_l_cache_mode_pt = L2_C;
   7179 	pte_l2_s_cache_mode_pt = L2_C;
   7180 
   7181 #ifdef XSCALE_CACHE_READ_WRITE_ALLOCATE
   7182 	/*
   7183 	 * The XScale core has an enhanced mode where writes that
   7184 	 * miss the cache cause a cache line to be allocated.  This
   7185 	 * is significantly faster than the traditional, write-through
   7186 	 * behavior of this case.
   7187 	 */
   7188 	pte_l1_s_cache_mode |= L1_S_XS_TEX(TEX_XSCALE_X);
   7189 	pte_l2_l_cache_mode |= L2_XS_L_TEX(TEX_XSCALE_X);
   7190 	pte_l2_s_cache_mode |= L2_XS_T_TEX(TEX_XSCALE_X);
   7191 #endif /* XSCALE_CACHE_READ_WRITE_ALLOCATE */
   7192 
   7193 #ifdef XSCALE_CACHE_WRITE_THROUGH
   7194 	/*
   7195 	 * Some versions of the XScale core have various bugs in
   7196 	 * their cache units, the work-around for which is to run
   7197 	 * the cache in write-through mode.  Unfortunately, this
   7198 	 * has a major (negative) impact on performance.  So, we
   7199 	 * go ahead and run fast-and-loose, in the hopes that we
   7200 	 * don't line up the planets in a way that will trip the
   7201 	 * bugs.
   7202 	 *
   7203 	 * However, we give you the option to be slow-but-correct.
   7204 	 */
   7205 	write_through = 1;
   7206 #elif defined(XSCALE_CACHE_WRITE_BACK)
   7207 	/* force write back cache mode */
   7208 	write_through = 0;
   7209 #elif defined(CPU_XSCALE_PXA250) || defined(CPU_XSCALE_PXA270)
   7210 	/*
   7211 	 * Intel PXA2[15]0 processors are known to have a bug in
   7212 	 * write-back cache on revision 4 and earlier (stepping
   7213 	 * A[01] and B[012]).  Fixed for C0 and later.
   7214 	 */
   7215 	{
   7216 		uint32_t id, type;
   7217 
   7218 		id = cpufunc_id();
   7219 		type = id & ~(CPU_ID_XSCALE_COREREV_MASK|CPU_ID_REVISION_MASK);
   7220 
   7221 		if (type == CPU_ID_PXA250 || type == CPU_ID_PXA210) {
   7222 			if ((id & CPU_ID_REVISION_MASK) < 5) {
   7223 				/* write through for stepping A0-1 and B0-2 */
   7224 				write_through = 1;
   7225 			}
   7226 		}
   7227 	}
   7228 #endif /* XSCALE_CACHE_WRITE_THROUGH */
   7229 
   7230 	if (write_through) {
   7231 		pte_l1_s_cache_mode = L1_S_C;
   7232 		pte_l2_l_cache_mode = L2_C;
   7233 		pte_l2_s_cache_mode = L2_C;
   7234 	}
   7235 
   7236 #if (ARM_NMMUS > 1)
   7237 	xscale_use_minidata = 1;
   7238 #endif
   7239 
   7240 	pte_l1_s_prot_u = L1_S_PROT_U_xscale;
   7241 	pte_l1_s_prot_w = L1_S_PROT_W_xscale;
   7242 	pte_l1_s_prot_ro = L1_S_PROT_RO_xscale;
   7243 	pte_l1_s_prot_mask = L1_S_PROT_MASK_xscale;
   7244 
   7245 	pte_l2_s_prot_u = L2_S_PROT_U_xscale;
   7246 	pte_l2_s_prot_w = L2_S_PROT_W_xscale;
   7247 	pte_l2_s_prot_ro = L2_S_PROT_RO_xscale;
   7248 	pte_l2_s_prot_mask = L2_S_PROT_MASK_xscale;
   7249 
   7250 	pte_l2_l_prot_u = L2_L_PROT_U_xscale;
   7251 	pte_l2_l_prot_w = L2_L_PROT_W_xscale;
   7252 	pte_l2_l_prot_ro = L2_L_PROT_RO_xscale;
   7253 	pte_l2_l_prot_mask = L2_L_PROT_MASK_xscale;
   7254 
   7255 	pte_l1_ss_proto = L1_SS_PROTO_xscale;
   7256 	pte_l1_s_proto = L1_S_PROTO_xscale;
   7257 	pte_l1_c_proto = L1_C_PROTO_xscale;
   7258 	pte_l2_s_proto = L2_S_PROTO_xscale;
   7259 
   7260 	pmap_copy_page_func = pmap_copy_page_xscale;
   7261 	pmap_zero_page_func = pmap_zero_page_xscale;
   7262 
   7263 	/*
   7264 	 * Disable ECC protection of page table access, for now.
   7265 	 */
   7266 	auxctl = armreg_auxctl_read();
   7267 	auxctl &= ~XSCALE_AUXCTL_P;
   7268 	armreg_auxctl_write(auxctl);
   7269 }
   7270 
   7271 /*
   7272  * xscale_setup_minidata:
   7273  *
   7274  *	Set up the mini-data cache clean area.  We require the
   7275  *	caller to allocate the right amount of physically and
   7276  *	virtually contiguous space.
   7277  */
   7278 void
   7279 xscale_setup_minidata(vaddr_t l1pt, vaddr_t va, paddr_t pa)
   7280 {
   7281 	extern vaddr_t xscale_minidata_clean_addr;
   7282 	extern vsize_t xscale_minidata_clean_size; /* already initialized */
   7283 	pd_entry_t *pde = (pd_entry_t *) l1pt;
   7284 	vsize_t size;
   7285 	uint32_t auxctl;
   7286 
   7287 	xscale_minidata_clean_addr = va;
   7288 
   7289 	/* Round it to page size. */
   7290 	size = (xscale_minidata_clean_size + L2_S_OFFSET) & L2_S_FRAME;
   7291 
   7292 	for (; size != 0;
   7293 	     va += L2_S_SIZE, pa += L2_S_SIZE, size -= L2_S_SIZE) {
   7294 		const size_t l1slot = l1pte_index(va);
   7295 		pt_entry_t *ptep = (pt_entry_t *) kernel_pt_lookup(l1pte_pa(pde[l1slot]));
   7296 		if (ptep == NULL)
   7297 			panic("xscale_setup_minidata: can't find L2 table for "
   7298 			    "VA 0x%08lx", va);
   7299 
   7300 		ptep += l2pte_index(va);
   7301 		pt_entry_t opte = *ptep;
   7302 		l2pte_set(ptep,
   7303 		    L2_S_PROTO | pa | L2_S_PROT(PTE_KERNEL, VM_PROT_READ)
   7304 		    | L2_C | L2_XS_T_TEX(TEX_XSCALE_X), opte);
   7305 	}
   7306 
   7307 	/*
   7308 	 * Configure the mini-data cache for write-back with
   7309 	 * read/write-allocate.
   7310 	 *
   7311 	 * NOTE: In order to reconfigure the mini-data cache, we must
   7312 	 * make sure it contains no valid data!  In order to do that,
   7313 	 * we must issue a global data cache invalidate command!
   7314 	 *
   7315 	 * WE ASSUME WE ARE RUNNING UN-CACHED WHEN THIS ROUTINE IS CALLED!
   7316 	 * THIS IS VERY IMPORTANT!
   7317 	 */
   7318 
   7319 	/* Invalidate data and mini-data. */
   7320 	__asm volatile("mcr p15, 0, %0, c7, c6, 0" : : "r" (0));
   7321 	auxctl = armreg_auxctl_read();
   7322 	auxctl = (auxctl & ~XSCALE_AUXCTL_MD_MASK) | XSCALE_AUXCTL_MD_WB_RWA;
   7323 	armreg_auxctl_write(auxctl);
   7324 }
   7325 
   7326 /*
   7327  * Change the PTEs for the specified kernel mappings such that they
   7328  * will use the mini data cache instead of the main data cache.
   7329  */
   7330 void
   7331 pmap_uarea(vaddr_t va)
   7332 {
   7333 	vaddr_t next_bucket, eva;
   7334 
   7335 #if (ARM_NMMUS > 1)
   7336 	if (xscale_use_minidata == 0)
   7337 		return;
   7338 #endif
   7339 
   7340 	eva = va + USPACE;
   7341 
   7342 	while (va < eva) {
   7343 		next_bucket = L2_NEXT_BUCKET_VA(va);
   7344 		if (next_bucket > eva)
   7345 			next_bucket = eva;
   7346 
   7347 		struct l2_bucket *l2b = pmap_get_l2_bucket(pmap_kernel(), va);
   7348 		KDASSERT(l2b != NULL);
   7349 
   7350 		pt_entry_t * const sptep = &l2b->l2b_kva[l2pte_index(va)];
   7351 		pt_entry_t *ptep = sptep;
   7352 
   7353 		while (va < next_bucket) {
   7354 			const pt_entry_t opte = *ptep;
   7355 			if (!l2pte_minidata_p(opte)) {
   7356 				cpu_dcache_wbinv_range(va, PAGE_SIZE);
   7357 				cpu_tlb_flushD_SE(va);
   7358 				l2pte_set(ptep, opte & ~L2_B, opte);
   7359 			}
   7360 			ptep += PAGE_SIZE / L2_S_SIZE;
   7361 			va += PAGE_SIZE;
   7362 		}
   7363 		PTE_SYNC_RANGE(sptep, (u_int)(ptep - sptep));
   7364 	}
   7365 	cpu_cpwait();
   7366 }
   7367 #endif /* ARM_MMU_XSCALE == 1 */
   7368 
   7369 
   7370 #if defined(CPU_ARM11MPCORE)
   7371 
   7372 void
   7373 pmap_pte_init_arm11mpcore(void)
   7374 {
   7375 
   7376 	/* cache mode is controlled by 5 bits (B, C, TEX) */
   7377 	pte_l1_s_cache_mask = L1_S_CACHE_MASK_armv6;
   7378 	pte_l2_l_cache_mask = L2_L_CACHE_MASK_armv6;
   7379 #if defined(ARM11MPCORE_COMPAT_MMU) || defined(ARMV6_EXTENDED_SMALL_PAGE)
   7380 	/* use extended small page (without APn, with TEX) */
   7381 	pte_l2_s_cache_mask = L2_XS_CACHE_MASK_armv6;
   7382 #else
   7383 	pte_l2_s_cache_mask = L2_S_CACHE_MASK_armv6c;
   7384 #endif
   7385 
   7386 	/* write-back, write-allocate */
   7387 	pte_l1_s_cache_mode = L1_S_C | L1_S_B | L1_S_V6_TEX(0x01);
   7388 	pte_l2_l_cache_mode = L2_C | L2_B | L2_V6_L_TEX(0x01);
   7389 #if defined(ARM11MPCORE_COMPAT_MMU) || defined(ARMV6_EXTENDED_SMALL_PAGE)
   7390 	pte_l2_s_cache_mode = L2_C | L2_B | L2_V6_XS_TEX(0x01);
   7391 #else
   7392 	/* no TEX. read-allocate */
   7393 	pte_l2_s_cache_mode = L2_C | L2_B;
   7394 #endif
   7395 	/*
   7396 	 * write-back, write-allocate for page tables.
   7397 	 */
   7398 	pte_l1_s_cache_mode_pt = L1_S_C | L1_S_B | L1_S_V6_TEX(0x01);
   7399 	pte_l2_l_cache_mode_pt = L2_C | L2_B | L2_V6_L_TEX(0x01);
   7400 #if defined(ARM11MPCORE_COMPAT_MMU) || defined(ARMV6_EXTENDED_SMALL_PAGE)
   7401 	pte_l2_s_cache_mode_pt = L2_C | L2_B | L2_V6_XS_TEX(0x01);
   7402 #else
   7403 	pte_l2_s_cache_mode_pt = L2_C | L2_B;
   7404 #endif
   7405 
   7406 	pte_l1_s_prot_u = L1_S_PROT_U_armv6;
   7407 	pte_l1_s_prot_w = L1_S_PROT_W_armv6;
   7408 	pte_l1_s_prot_ro = L1_S_PROT_RO_armv6;
   7409 	pte_l1_s_prot_mask = L1_S_PROT_MASK_armv6;
   7410 
   7411 #if defined(ARM11MPCORE_COMPAT_MMU) || defined(ARMV6_EXTENDED_SMALL_PAGE)
   7412 	pte_l2_s_prot_u = L2_S_PROT_U_armv6n;
   7413 	pte_l2_s_prot_w = L2_S_PROT_W_armv6n;
   7414 	pte_l2_s_prot_ro = L2_S_PROT_RO_armv6n;
   7415 	pte_l2_s_prot_mask = L2_S_PROT_MASK_armv6n;
   7416 
   7417 #else
   7418 	/* with AP[0..3] */
   7419 	pte_l2_s_prot_u = L2_S_PROT_U_generic;
   7420 	pte_l2_s_prot_w = L2_S_PROT_W_generic;
   7421 	pte_l2_s_prot_ro = L2_S_PROT_RO_generic;
   7422 	pte_l2_s_prot_mask = L2_S_PROT_MASK_generic;
   7423 #endif
   7424 
   7425 #ifdef	ARM11MPCORE_COMPAT_MMU
   7426 	/* with AP[0..3] */
   7427 	pte_l2_l_prot_u = L2_L_PROT_U_generic;
   7428 	pte_l2_l_prot_w = L2_L_PROT_W_generic;
   7429 	pte_l2_l_prot_ro = L2_L_PROT_RO_generic;
   7430 	pte_l2_l_prot_mask = L2_L_PROT_MASK_generic;
   7431 
   7432 	pte_l1_ss_proto = L1_SS_PROTO_armv6;
   7433 	pte_l1_s_proto = L1_S_PROTO_armv6;
   7434 	pte_l1_c_proto = L1_C_PROTO_armv6;
   7435 	pte_l2_s_proto = L2_S_PROTO_armv6c;
   7436 #else
   7437 	pte_l2_l_prot_u = L2_L_PROT_U_armv6n;
   7438 	pte_l2_l_prot_w = L2_L_PROT_W_armv6n;
   7439 	pte_l2_l_prot_ro = L2_L_PROT_RO_armv6n;
   7440 	pte_l2_l_prot_mask = L2_L_PROT_MASK_armv6n;
   7441 
   7442 	pte_l1_ss_proto = L1_SS_PROTO_armv6;
   7443 	pte_l1_s_proto = L1_S_PROTO_armv6;
   7444 	pte_l1_c_proto = L1_C_PROTO_armv6;
   7445 	pte_l2_s_proto = L2_S_PROTO_armv6n;
   7446 #endif
   7447 
   7448 	pmap_copy_page_func = pmap_copy_page_generic;
   7449 	pmap_zero_page_func = pmap_zero_page_generic;
   7450 	pmap_needs_pte_sync = 1;
   7451 }
   7452 #endif	/* CPU_ARM11MPCORE */
   7453 
   7454 
   7455 #if ARM_MMU_V7 == 1
   7456 void
   7457 pmap_pte_init_armv7(void)
   7458 {
   7459 	/*
   7460 	 * The ARMv7-A MMU is mostly compatible with generic. If the
   7461 	 * AP field is zero, that now means "no access" rather than
   7462 	 * read-only. The prototypes are a little different because of
   7463 	 * the XN bit.
   7464 	 */
   7465 	pmap_pte_init_generic();
   7466 
   7467 	pmap_needs_pte_sync = 1;
   7468 
   7469 	pte_l1_s_cache_mask = L1_S_CACHE_MASK_armv7;
   7470 	pte_l2_l_cache_mask = L2_L_CACHE_MASK_armv7;
   7471 	pte_l2_s_cache_mask = L2_S_CACHE_MASK_armv7;
   7472 
   7473 	/*
   7474 	 * If the core support coherent walk then updates to translation tables
   7475 	 * do not require a clean to the point of unification to ensure
   7476 	 * visibility by subsequent translation table walks.  That means we can
   7477 	 * map everything shareable and cached and the right thing will happen.
   7478 	 */
   7479         if (__SHIFTOUT(armreg_mmfr3_read(), __BITS(23,20))) {
   7480 		pmap_needs_pte_sync = 0;
   7481 
   7482 		/*
   7483 		 * write-back, no write-allocate, shareable for normal pages.
   7484 		 */
   7485 		pte_l1_s_cache_mode |= L1_S_V6_S;
   7486 		pte_l2_l_cache_mode |= L2_XS_S;
   7487 		pte_l2_s_cache_mode |= L2_XS_S;
   7488 	}
   7489 
   7490 	/*
   7491 	 * Page tables are just all other memory.  We can use write-back since
   7492 	 * pmap_needs_pte_sync is 1 (or the MMU can read out of cache).
   7493 	 */
   7494 	pte_l1_s_cache_mode_pt = pte_l1_s_cache_mode;
   7495 	pte_l2_l_cache_mode_pt = pte_l2_l_cache_mode;
   7496 	pte_l2_s_cache_mode_pt = pte_l2_s_cache_mode;
   7497 
   7498 	/*
   7499 	 * Check the Memory Model Features to see if this CPU supports
   7500 	 * the TLBIASID coproc op.
   7501 	 */
   7502 	if (__SHIFTOUT(armreg_mmfr2_read(), __BITS(16,19)) >= 2) {
   7503 		arm_has_tlbiasid_p = true;
   7504 	}
   7505 
   7506 	pte_l1_s_prot_u = L1_S_PROT_U_armv7;
   7507 	pte_l1_s_prot_w = L1_S_PROT_W_armv7;
   7508 	pte_l1_s_prot_ro = L1_S_PROT_RO_armv7;
   7509 	pte_l1_s_prot_mask = L1_S_PROT_MASK_armv7;
   7510 
   7511 	pte_l2_s_prot_u = L2_S_PROT_U_armv7;
   7512 	pte_l2_s_prot_w = L2_S_PROT_W_armv7;
   7513 	pte_l2_s_prot_ro = L2_S_PROT_RO_armv7;
   7514 	pte_l2_s_prot_mask = L2_S_PROT_MASK_armv7;
   7515 
   7516 	pte_l2_l_prot_u = L2_L_PROT_U_armv7;
   7517 	pte_l2_l_prot_w = L2_L_PROT_W_armv7;
   7518 	pte_l2_l_prot_ro = L2_L_PROT_RO_armv7;
   7519 	pte_l2_l_prot_mask = L2_L_PROT_MASK_armv7;
   7520 
   7521 	pte_l1_ss_proto = L1_SS_PROTO_armv7;
   7522 	pte_l1_s_proto = L1_S_PROTO_armv7;
   7523 	pte_l1_c_proto = L1_C_PROTO_armv7;
   7524 	pte_l2_s_proto = L2_S_PROTO_armv7;
   7525 
   7526 }
   7527 #endif /* ARM_MMU_V7 */
   7528 
   7529 /*
   7530  * return the PA of the current L1 table, for use when handling a crash dump
   7531  */
   7532 uint32_t
   7533 pmap_kernel_L1_addr(void)
   7534 {
   7535 #ifdef ARM_MMU_EXTENDED
   7536 	return pmap_kernel()->pm_l1_pa;
   7537 #else
   7538 	return pmap_kernel()->pm_l1->l1_physaddr;
   7539 #endif
   7540 }
   7541 
   7542 #if defined(DDB)
   7543 /*
   7544  * A couple of ddb-callable functions for dumping pmaps
   7545  */
   7546 void pmap_dump(pmap_t);
   7547 
   7548 static pt_entry_t ncptes[64];
   7549 static void pmap_dump_ncpg(pmap_t);
   7550 
   7551 void
   7552 pmap_dump(pmap_t pm)
   7553 {
   7554 	struct l2_dtable *l2;
   7555 	struct l2_bucket *l2b;
   7556 	pt_entry_t *ptep, pte;
   7557 	vaddr_t l2_va, l2b_va, va;
   7558 	int i, j, k, occ, rows = 0;
   7559 
   7560 	if (pm == pmap_kernel())
   7561 		printf("pmap_kernel (%p): ", pm);
   7562 	else
   7563 		printf("user pmap (%p): ", pm);
   7564 
   7565 #ifdef ARM_MMU_EXTENDED
   7566 	printf("l1 at %p\n", pmap_l1_kva(pm));
   7567 #else
   7568 	printf("domain %d, l1 at %p\n", pmap_domain(pm), pmap_l1_kva(pm));
   7569 #endif
   7570 
   7571 	l2_va = 0;
   7572 	for (i = 0; i < L2_SIZE; i++, l2_va += 0x01000000) {
   7573 		l2 = pm->pm_l2[i];
   7574 
   7575 		if (l2 == NULL || l2->l2_occupancy == 0)
   7576 			continue;
   7577 
   7578 		l2b_va = l2_va;
   7579 		for (j = 0; j < L2_BUCKET_SIZE; j++, l2b_va += 0x00100000) {
   7580 			l2b = &l2->l2_bucket[j];
   7581 
   7582 			if (l2b->l2b_occupancy == 0 || l2b->l2b_kva == NULL)
   7583 				continue;
   7584 
   7585 			ptep = l2b->l2b_kva;
   7586 
   7587 			for (k = 0; k < 256 && ptep[k] == 0; k++)
   7588 				;
   7589 
   7590 			k &= ~63;
   7591 			occ = l2b->l2b_occupancy;
   7592 			va = l2b_va + (k * 4096);
   7593 			for (; k < 256; k++, va += 0x1000) {
   7594 				char ch = ' ';
   7595 				if ((k % 64) == 0) {
   7596 					if ((rows % 8) == 0) {
   7597 						printf(
   7598 "          |0000   |8000   |10000  |18000  |20000  |28000  |30000  |38000\n");
   7599 					}
   7600 					printf("%08lx: ", va);
   7601 				}
   7602 
   7603 				ncptes[k & 63] = 0;
   7604 				pte = ptep[k];
   7605 				if (pte == 0) {
   7606 					ch = '.';
   7607 				} else {
   7608 					occ--;
   7609 					switch (pte & 0x0c) {
   7610 					case 0x00:
   7611 						ch = 'D'; /* No cache No buff */
   7612 						break;
   7613 					case 0x04:
   7614 						ch = 'B'; /* No cache buff */
   7615 						break;
   7616 					case 0x08:
   7617 						if (pte & 0x40)
   7618 							ch = 'm';
   7619 						else
   7620 						   ch = 'C'; /* Cache No buff */
   7621 						break;
   7622 					case 0x0c:
   7623 						ch = 'F'; /* Cache Buff */
   7624 						break;
   7625 					}
   7626 
   7627 					if ((pte & L2_S_PROT_U) == L2_S_PROT_U)
   7628 						ch += 0x20;
   7629 
   7630 					if ((pte & 0xc) == 0)
   7631 						ncptes[k & 63] = pte;
   7632 				}
   7633 
   7634 				if ((k % 64) == 63) {
   7635 					rows++;
   7636 					printf("%c\n", ch);
   7637 					pmap_dump_ncpg(pm);
   7638 					if (occ == 0)
   7639 						break;
   7640 				} else
   7641 					printf("%c", ch);
   7642 			}
   7643 		}
   7644 	}
   7645 }
   7646 
   7647 static void
   7648 pmap_dump_ncpg(pmap_t pm)
   7649 {
   7650 	struct vm_page *pg;
   7651 	struct vm_page_md *md;
   7652 	struct pv_entry *pv;
   7653 	int i;
   7654 
   7655 	for (i = 0; i < 63; i++) {
   7656 		if (ncptes[i] == 0)
   7657 			continue;
   7658 
   7659 		pg = PHYS_TO_VM_PAGE(l2pte_pa(ncptes[i]));
   7660 		if (pg == NULL)
   7661 			continue;
   7662 		md = VM_PAGE_TO_MD(pg);
   7663 
   7664 		printf(" pa 0x%08lx: krw %d kro %d urw %d uro %d\n",
   7665 		    VM_PAGE_TO_PHYS(pg),
   7666 		    md->krw_mappings, md->kro_mappings,
   7667 		    md->urw_mappings, md->uro_mappings);
   7668 
   7669 		SLIST_FOREACH(pv, &md->pvh_list, pv_link) {
   7670 			printf("   %c va 0x%08lx, flags 0x%x\n",
   7671 			    (pm == pv->pv_pmap) ? '*' : ' ',
   7672 			    pv->pv_va, pv->pv_flags);
   7673 		}
   7674 	}
   7675 }
   7676 #endif
   7677 
   7678 #ifdef PMAP_STEAL_MEMORY
   7679 void
   7680 pmap_boot_pageadd(pv_addr_t *newpv)
   7681 {
   7682 	pv_addr_t *pv, *npv;
   7683 
   7684 	if ((pv = SLIST_FIRST(&pmap_boot_freeq)) != NULL) {
   7685 		if (newpv->pv_pa < pv->pv_va) {
   7686 			KASSERT(newpv->pv_pa + newpv->pv_size <= pv->pv_pa);
   7687 			if (newpv->pv_pa + newpv->pv_size == pv->pv_pa) {
   7688 				newpv->pv_size += pv->pv_size;
   7689 				SLIST_REMOVE_HEAD(&pmap_boot_freeq, pv_list);
   7690 			}
   7691 			pv = NULL;
   7692 		} else {
   7693 			for (; (npv = SLIST_NEXT(pv, pv_list)) != NULL;
   7694 			     pv = npv) {
   7695 				KASSERT(pv->pv_pa + pv->pv_size < npv->pv_pa);
   7696 				KASSERT(pv->pv_pa < newpv->pv_pa);
   7697 				if (newpv->pv_pa > npv->pv_pa)
   7698 					continue;
   7699 				if (pv->pv_pa + pv->pv_size == newpv->pv_pa) {
   7700 					pv->pv_size += newpv->pv_size;
   7701 					return;
   7702 				}
   7703 				if (newpv->pv_pa + newpv->pv_size < npv->pv_pa)
   7704 					break;
   7705 				newpv->pv_size += npv->pv_size;
   7706 				SLIST_INSERT_AFTER(pv, newpv, pv_list);
   7707 				SLIST_REMOVE_AFTER(newpv, pv_list);
   7708 				return;
   7709 			}
   7710 		}
   7711 	}
   7712 
   7713 	if (pv) {
   7714 		SLIST_INSERT_AFTER(pv, newpv, pv_list);
   7715 	} else {
   7716 		SLIST_INSERT_HEAD(&pmap_boot_freeq, newpv, pv_list);
   7717 	}
   7718 }
   7719 
   7720 void
   7721 pmap_boot_pagealloc(psize_t amount, psize_t mask, psize_t match,
   7722 	pv_addr_t *rpv)
   7723 {
   7724 	pv_addr_t *pv, **pvp;
   7725 	struct vm_physseg *ps;
   7726 	size_t i;
   7727 
   7728 	KASSERT(amount & PGOFSET);
   7729 	KASSERT((mask & PGOFSET) == 0);
   7730 	KASSERT((match & PGOFSET) == 0);
   7731 	KASSERT(amount != 0);
   7732 
   7733 	for (pvp = &SLIST_FIRST(&pmap_boot_freeq);
   7734 	     (pv = *pvp) != NULL;
   7735 	     pvp = &SLIST_NEXT(pv, pv_list)) {
   7736 		pv_addr_t *newpv;
   7737 		psize_t off;
   7738 		/*
   7739 		 * If this entry is too small to satify the request...
   7740 		 */
   7741 		KASSERT(pv->pv_size > 0);
   7742 		if (pv->pv_size < amount)
   7743 			continue;
   7744 
   7745 		for (off = 0; off <= mask; off += PAGE_SIZE) {
   7746 			if (((pv->pv_pa + off) & mask) == match
   7747 			    && off + amount <= pv->pv_size)
   7748 				break;
   7749 		}
   7750 		if (off > mask)
   7751 			continue;
   7752 
   7753 		rpv->pv_va = pv->pv_va + off;
   7754 		rpv->pv_pa = pv->pv_pa + off;
   7755 		rpv->pv_size = amount;
   7756 		pv->pv_size -= amount;
   7757 		if (pv->pv_size == 0) {
   7758 			KASSERT(off == 0);
   7759 			KASSERT((vaddr_t) pv == rpv->pv_va);
   7760 			*pvp = SLIST_NEXT(pv, pv_list);
   7761 		} else if (off == 0) {
   7762 			KASSERT((vaddr_t) pv == rpv->pv_va);
   7763 			newpv = (pv_addr_t *) (rpv->pv_va + amount);
   7764 			*newpv = *pv;
   7765 			newpv->pv_pa += amount;
   7766 			newpv->pv_va += amount;
   7767 			*pvp = newpv;
   7768 		} else if (off < pv->pv_size) {
   7769 			newpv = (pv_addr_t *) (rpv->pv_va + amount);
   7770 			*newpv = *pv;
   7771 			newpv->pv_size -= off;
   7772 			newpv->pv_pa += off + amount;
   7773 			newpv->pv_va += off + amount;
   7774 
   7775 			SLIST_NEXT(pv, pv_list) = newpv;
   7776 			pv->pv_size = off;
   7777 		} else {
   7778 			KASSERT((vaddr_t) pv != rpv->pv_va);
   7779 		}
   7780 		memset((void *)rpv->pv_va, 0, amount);
   7781 		return;
   7782 	}
   7783 
   7784 	if (vm_nphysseg == 0)
   7785 		panic("pmap_boot_pagealloc: couldn't allocate memory");
   7786 
   7787 	for (pvp = &SLIST_FIRST(&pmap_boot_freeq);
   7788 	     (pv = *pvp) != NULL;
   7789 	     pvp = &SLIST_NEXT(pv, pv_list)) {
   7790 		if (SLIST_NEXT(pv, pv_list) == NULL)
   7791 			break;
   7792 	}
   7793 	KASSERT(mask == 0);
   7794 	for (i = 0; i < vm_nphysseg; i++) {
   7795 		ps = VM_PHYSMEM_PTR(i);
   7796 		if (ps->avail_start == atop(pv->pv_pa + pv->pv_size)
   7797 		    && pv->pv_va + pv->pv_size <= ptoa(ps->avail_end)) {
   7798 			rpv->pv_va = pv->pv_va;
   7799 			rpv->pv_pa = pv->pv_pa;
   7800 			rpv->pv_size = amount;
   7801 			*pvp = NULL;
   7802 			pmap_map_chunk(kernel_l1pt.pv_va,
   7803 			     ptoa(ps->avail_start) + (pv->pv_va - pv->pv_pa),
   7804 			     ptoa(ps->avail_start),
   7805 			     amount - pv->pv_size,
   7806 			     VM_PROT_READ|VM_PROT_WRITE,
   7807 			     PTE_CACHE);
   7808 			ps->avail_start += atop(amount - pv->pv_size);
   7809 			/*
   7810 			 * If we consumed the entire physseg, remove it.
   7811 			 */
   7812 			if (ps->avail_start == ps->avail_end) {
   7813 				for (--vm_nphysseg; i < vm_nphysseg; i++)
   7814 					VM_PHYSMEM_PTR_SWAP(i, i + 1);
   7815 			}
   7816 			memset((void *)rpv->pv_va, 0, rpv->pv_size);
   7817 			return;
   7818 		}
   7819 	}
   7820 
   7821 	panic("pmap_boot_pagealloc: couldn't allocate memory");
   7822 }
   7823 
   7824 vaddr_t
   7825 pmap_steal_memory(vsize_t size, vaddr_t *vstartp, vaddr_t *vendp)
   7826 {
   7827 	pv_addr_t pv;
   7828 
   7829 	pmap_boot_pagealloc(size, 0, 0, &pv);
   7830 
   7831 	return pv.pv_va;
   7832 }
   7833 #endif /* PMAP_STEAL_MEMORY */
   7834 
   7835 SYSCTL_SETUP(sysctl_machdep_pmap_setup, "sysctl machdep.kmpages setup")
   7836 {
   7837 	sysctl_createv(clog, 0, NULL, NULL,
   7838 			CTLFLAG_PERMANENT,
   7839 			CTLTYPE_NODE, "machdep", NULL,
   7840 			NULL, 0, NULL, 0,
   7841 			CTL_MACHDEP, CTL_EOL);
   7842 
   7843 	sysctl_createv(clog, 0, NULL, NULL,
   7844 			CTLFLAG_PERMANENT,
   7845 			CTLTYPE_INT, "kmpages",
   7846 			SYSCTL_DESCR("count of pages allocated to kernel memory allocators"),
   7847 			NULL, 0, &pmap_kmpages, 0,
   7848 			CTL_MACHDEP, CTL_CREATE, CTL_EOL);
   7849 }
   7850 
   7851 #ifdef PMAP_NEED_ALLOC_POOLPAGE
   7852 struct vm_page *
   7853 arm_pmap_alloc_poolpage(int flags)
   7854 {
   7855 	/*
   7856 	 * On some systems, only some pages may be "coherent" for dma and we
   7857 	 * want to prefer those for pool pages (think mbufs) but fallback to
   7858 	 * any page if none is available.  But we can only fallback if we
   7859 	 * aren't direct mapping memory or all of memory can be direct-mapped.
   7860 	 * If that isn't true, pool changes can only come from direct-mapped
   7861 	 * memory.
   7862 	 */
   7863 	if (arm_poolpage_vmfreelist != VM_FREELIST_DEFAULT) {
   7864 		return uvm_pagealloc_strat(NULL, 0, NULL, flags,
   7865 		    UVM_PGA_STRAT_FALLBACK,
   7866 		    arm_poolpage_vmfreelist);
   7867 	}
   7868 
   7869 	return uvm_pagealloc(NULL, 0, NULL, flags);
   7870 }
   7871 #endif
   7872 
   7873 #if defined(ARM_MMU_EXTENDED) && defined(MULTIPROCESSOR)
   7874 void
   7875 pmap_md_tlb_info_attach(struct pmap_tlb_info *ti, struct cpu_info *ci)
   7876 {
   7877         /* nothing */
   7878 }
   7879 
   7880 int
   7881 pic_ipi_shootdown(void *arg)
   7882 {
   7883 #if PMAP_TLB_NEED_SHOOTDOWN
   7884 	pmap_tlb_shootdown_process();
   7885 #endif
   7886 	return 1;
   7887 }
   7888 #endif /* ARM_MMU_EXTENDED && MULTIPROCESSOR */
   7889 
   7890 
   7891 #ifdef __HAVE_MM_MD_DIRECT_MAPPED_PHYS
   7892 vaddr_t
   7893 pmap_direct_mapped_phys(paddr_t pa, bool *ok_p, vaddr_t va)
   7894 {
   7895 	bool ok = false;
   7896 	if (physical_start <= pa && pa < physical_end) {
   7897 #ifdef KERNEL_BASE_VOFFSET
   7898 		const vaddr_t newva = pa + KERNEL_BASE_VOFFSET;
   7899 #else
   7900 		const vaddr_t newva = KERNEL_BASE + pa - physical_start;
   7901 #endif
   7902 #ifdef ARM_MMU_EXTENDED
   7903 		if (newva >= KERNEL_BASE && newva < pmap_directlimit) {
   7904 #endif
   7905 			va = newva;
   7906 			ok = true;
   7907 #ifdef ARM_MMU_EXTENDED
   7908 		}
   7909 #endif
   7910 	}
   7911 	KASSERT(ok_p);
   7912 	*ok_p = ok;
   7913 	return va;
   7914 }
   7915 
   7916 vaddr_t
   7917 pmap_map_poolpage(paddr_t pa)
   7918 {
   7919 	bool ok __diagused;
   7920 	vaddr_t va = pmap_direct_mapped_phys(pa, &ok, 0);
   7921 	KASSERTMSG(ok, "pa %#lx not direct mappable", pa);
   7922 #if defined(PMAP_CACHE_VIPT) && !defined(ARM_MMU_EXTENDED)
   7923 	if (arm_cache_prefer_mask != 0) {
   7924 		struct vm_page * const pg = PHYS_TO_VM_PAGE(pa);
   7925 		struct vm_page_md * const md = VM_PAGE_TO_MD(pg);
   7926 		pmap_acquire_page_lock(md);
   7927 		pmap_vac_me_harder(md, pa, pmap_kernel(), va);
   7928 		pmap_release_page_lock(md);
   7929 	}
   7930 #endif
   7931 	return va;
   7932 }
   7933 
   7934 paddr_t
   7935 pmap_unmap_poolpage(vaddr_t va)
   7936 {
   7937 	KASSERT(va >= KERNEL_BASE);
   7938 #ifdef PMAP_CACHE_VIVT
   7939 	cpu_idcache_wbinv_range(va, PAGE_SIZE);
   7940 #endif
   7941 #if defined(KERNEL_BASE_VOFFSET)
   7942         return va - KERNEL_BASE_VOFFSET;
   7943 #else
   7944         return va - KERNEL_BASE + physical_start;
   7945 #endif
   7946 }
   7947 #endif /* __HAVE_MM_MD_DIRECT_MAPPED_PHYS */
   7948