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pmap.c revision 1.125
      1 /*	$NetBSD: pmap.c,v 1.125 2003/02/21 00:23:03 chris Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2002 Wasabi Systems, Inc.
      5  * Copyright (c) 2001 Richard Earnshaw
      6  * Copyright (c) 2001-2002 Christopher Gilbert
      7  * All rights reserved.
      8  *
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the company nor the name of the author may be used to
     15  *    endorse or promote products derived from this software without specific
     16  *    prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     19  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     20  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     21  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     22  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 /*-
     32  * Copyright (c) 1999 The NetBSD Foundation, Inc.
     33  * All rights reserved.
     34  *
     35  * This code is derived from software contributed to The NetBSD Foundation
     36  * by Charles M. Hannum.
     37  *
     38  * Redistribution and use in source and binary forms, with or without
     39  * modification, are permitted provided that the following conditions
     40  * are met:
     41  * 1. Redistributions of source code must retain the above copyright
     42  *    notice, this list of conditions and the following disclaimer.
     43  * 2. Redistributions in binary form must reproduce the above copyright
     44  *    notice, this list of conditions and the following disclaimer in the
     45  *    documentation and/or other materials provided with the distribution.
     46  * 3. All advertising materials mentioning features or use of this software
     47  *    must display the following acknowledgement:
     48  *        This product includes software developed by the NetBSD
     49  *        Foundation, Inc. and its contributors.
     50  * 4. Neither the name of The NetBSD Foundation nor the names of its
     51  *    contributors may be used to endorse or promote products derived
     52  *    from this software without specific prior written permission.
     53  *
     54  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     55  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     56  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     57  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     58  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     59  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     60  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     61  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     62  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     63  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     64  * POSSIBILITY OF SUCH DAMAGE.
     65  */
     66 
     67 /*
     68  * Copyright (c) 1994-1998 Mark Brinicombe.
     69  * Copyright (c) 1994 Brini.
     70  * All rights reserved.
     71  *
     72  * This code is derived from software written for Brini by Mark Brinicombe
     73  *
     74  * Redistribution and use in source and binary forms, with or without
     75  * modification, are permitted provided that the following conditions
     76  * are met:
     77  * 1. Redistributions of source code must retain the above copyright
     78  *    notice, this list of conditions and the following disclaimer.
     79  * 2. Redistributions in binary form must reproduce the above copyright
     80  *    notice, this list of conditions and the following disclaimer in the
     81  *    documentation and/or other materials provided with the distribution.
     82  * 3. All advertising materials mentioning features or use of this software
     83  *    must display the following acknowledgement:
     84  *	This product includes software developed by Mark Brinicombe.
     85  * 4. The name of the author may not be used to endorse or promote products
     86  *    derived from this software without specific prior written permission.
     87  *
     88  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     89  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     90  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     91  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     92  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     93  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     94  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     95  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     96  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     97  *
     98  * RiscBSD kernel project
     99  *
    100  * pmap.c
    101  *
    102  * Machine dependant vm stuff
    103  *
    104  * Created      : 20/09/94
    105  */
    106 
    107 /*
    108  * Performance improvements, UVM changes, overhauls and part-rewrites
    109  * were contributed by Neil A. Carson <neil (at) causality.com>.
    110  */
    111 
    112 /*
    113  * The dram block info is currently referenced from the bootconfig.
    114  * This should be placed in a separate structure.
    115  */
    116 
    117 /*
    118  * Special compilation symbols
    119  * PMAP_DEBUG		- Build in pmap_debug_level code
    120  */
    121 
    122 /* Include header files */
    123 
    124 #include "opt_pmap_debug.h"
    125 #include "opt_ddb.h"
    126 
    127 #include <sys/types.h>
    128 #include <sys/param.h>
    129 #include <sys/kernel.h>
    130 #include <sys/systm.h>
    131 #include <sys/proc.h>
    132 #include <sys/malloc.h>
    133 #include <sys/user.h>
    134 #include <sys/pool.h>
    135 #include <sys/cdefs.h>
    136 
    137 #include <uvm/uvm.h>
    138 
    139 #include <machine/bootconfig.h>
    140 #include <machine/bus.h>
    141 #include <machine/pmap.h>
    142 #include <machine/pcb.h>
    143 #include <machine/param.h>
    144 #include <arm/arm32/katelib.h>
    145 
    146 __KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.125 2003/02/21 00:23:03 chris Exp $");
    147 
    148 #ifdef PMAP_DEBUG
    149 #define	PDEBUG(_lev_,_stat_) \
    150 	if (pmap_debug_level >= (_lev_)) \
    151         	((_stat_))
    152 int pmap_debug_level = -2;
    153 void pmap_dump_pvlist(vaddr_t phys, char *m);
    154 
    155 /*
    156  * for switching to potentially finer grained debugging
    157  */
    158 #define	PDB_FOLLOW	0x0001
    159 #define	PDB_INIT	0x0002
    160 #define	PDB_ENTER	0x0004
    161 #define	PDB_REMOVE	0x0008
    162 #define	PDB_CREATE	0x0010
    163 #define	PDB_PTPAGE	0x0020
    164 #define	PDB_GROWKERN	0x0040
    165 #define	PDB_BITS	0x0080
    166 #define	PDB_COLLECT	0x0100
    167 #define	PDB_PROTECT	0x0200
    168 #define	PDB_MAP_L1	0x0400
    169 #define	PDB_BOOTSTRAP	0x1000
    170 #define	PDB_PARANOIA	0x2000
    171 #define	PDB_WIRING	0x4000
    172 #define	PDB_PVDUMP	0x8000
    173 
    174 int debugmap = 0;
    175 int pmapdebug = PDB_PARANOIA | PDB_FOLLOW | PDB_GROWKERN | PDB_ENTER | PDB_REMOVE;
    176 #define	NPDEBUG(_lev_,_stat_) \
    177 	if (pmapdebug & (_lev_)) \
    178         	((_stat_))
    179 
    180 #else	/* PMAP_DEBUG */
    181 #define	PDEBUG(_lev_,_stat_) /* Nothing */
    182 #define NPDEBUG(_lev_,_stat_) /* Nothing */
    183 #endif	/* PMAP_DEBUG */
    184 
    185 struct pmap     kernel_pmap_store;
    186 
    187 /*
    188  * linked list of all non-kernel pmaps
    189  */
    190 
    191 static LIST_HEAD(, pmap) pmaps;
    192 
    193 /*
    194  * pool that pmap structures are allocated from
    195  */
    196 
    197 struct pool pmap_pmap_pool;
    198 
    199 /*
    200  * pool/cache that PT-PT's are allocated from
    201  */
    202 
    203 struct pool pmap_ptpt_pool;
    204 struct pool_cache pmap_ptpt_cache;
    205 u_int pmap_ptpt_cache_generation;
    206 
    207 static void *pmap_ptpt_page_alloc(struct pool *, int);
    208 static void pmap_ptpt_page_free(struct pool *, void *);
    209 
    210 struct pool_allocator pmap_ptpt_allocator = {
    211 	pmap_ptpt_page_alloc, pmap_ptpt_page_free,
    212 };
    213 
    214 static int pmap_ptpt_ctor(void *, void *, int);
    215 
    216 static pt_entry_t *csrc_pte, *cdst_pte;
    217 static vaddr_t csrcp, cdstp;
    218 
    219 char *memhook;
    220 extern caddr_t msgbufaddr;
    221 
    222 boolean_t pmap_initialized = FALSE;	/* Has pmap_init completed? */
    223 /*
    224  * locking data structures
    225  */
    226 
    227 static struct lock pmap_main_lock;
    228 static struct simplelock pvalloc_lock;
    229 static struct simplelock pmaps_lock;
    230 #ifdef LOCKDEBUG
    231 #define PMAP_MAP_TO_HEAD_LOCK() \
    232      (void) spinlockmgr(&pmap_main_lock, LK_SHARED, NULL)
    233 #define PMAP_MAP_TO_HEAD_UNLOCK() \
    234      (void) spinlockmgr(&pmap_main_lock, LK_RELEASE, NULL)
    235 
    236 #define PMAP_HEAD_TO_MAP_LOCK() \
    237      (void) spinlockmgr(&pmap_main_lock, LK_EXCLUSIVE, NULL)
    238 #define PMAP_HEAD_TO_MAP_UNLOCK() \
    239      (void) spinlockmgr(&pmap_main_lock, LK_RELEASE, NULL)
    240 #else
    241 #define	PMAP_MAP_TO_HEAD_LOCK()		/* nothing */
    242 #define	PMAP_MAP_TO_HEAD_UNLOCK()	/* nothing */
    243 #define	PMAP_HEAD_TO_MAP_LOCK()		/* nothing */
    244 #define	PMAP_HEAD_TO_MAP_UNLOCK()	/* nothing */
    245 #endif /* LOCKDEBUG */
    246 
    247 /*
    248  * pv_page management structures: locked by pvalloc_lock
    249  */
    250 
    251 TAILQ_HEAD(pv_pagelist, pv_page);
    252 static struct pv_pagelist pv_freepages;	/* list of pv_pages with free entrys */
    253 static struct pv_pagelist pv_unusedpgs; /* list of unused pv_pages */
    254 static unsigned int pv_nfpvents;	/* # of free pv entries */
    255 static struct pv_page *pv_initpage;	/* bootstrap page from kernel_map */
    256 static vaddr_t pv_cachedva;		/* cached VA for later use */
    257 
    258 #define PVE_LOWAT (PVE_PER_PVPAGE / 2)	/* free pv_entry low water mark */
    259 #define PVE_HIWAT (PVE_LOWAT + (PVE_PER_PVPAGE * 2))
    260 					/* high water mark */
    261 
    262 /*
    263  * local prototypes
    264  */
    265 
    266 static struct pv_entry	*pmap_add_pvpage(struct pv_page *, boolean_t);
    267 static struct pv_entry	*pmap_alloc_pv(struct pmap *, unsigned int);
    268 #define ALLOCPV_NEED	0	/* need PV now */
    269 #define ALLOCPV_TRY	1	/* just try to allocate, don't steal */
    270 #define ALLOCPV_NONEED	2	/* don't need PV, just growing cache */
    271 static struct pv_entry	*pmap_alloc_pvpage(struct pmap *, unsigned int);
    272 static void		 pmap_enter_pv(struct vm_page *,
    273 				       struct pv_entry *, struct pmap *,
    274 				       vaddr_t, struct vm_page *, unsigned int);
    275 static void		 pmap_free_pv(struct pmap *, struct pv_entry *);
    276 static void		 pmap_free_pvs(struct pmap *, struct pv_entry *);
    277 static void		 pmap_free_pv_doit(struct pv_entry *);
    278 static void		 pmap_free_pvpage(void);
    279 static boolean_t	 pmap_is_curpmap(struct pmap *);
    280 static struct pv_entry	*pmap_remove_pv(struct vm_page *, struct pmap *,
    281 					vaddr_t);
    282 #define PMAP_REMOVE_ALL		0	/* remove all mappings */
    283 #define PMAP_REMOVE_SKIPWIRED	1	/* skip wired mappings */
    284 
    285 static u_int pmap_modify_pv(struct pmap *, vaddr_t, struct vm_page *,
    286 			    u_int, u_int);
    287 
    288 /*
    289  * Structure that describes and L1 table.
    290  */
    291 struct l1pt {
    292 	SIMPLEQ_ENTRY(l1pt)	pt_queue;	/* Queue pointers */
    293 	struct pglist		pt_plist;	/* Allocated page list */
    294 	vaddr_t			pt_va;		/* Allocated virtual address */
    295 	unsigned int		pt_flags;	/* Flags */
    296 };
    297 #define	PTFLAG_STATIC		0x01		/* Statically allocated */
    298 #define	PTFLAG_KPT		0x02		/* Kernel pt's are mapped */
    299 #define	PTFLAG_CLEAN		0x04		/* L1 is clean */
    300 
    301 static void	pmap_free_l1pt(struct l1pt *);
    302 static int	pmap_allocpagedir(struct pmap *);
    303 static int	pmap_clean_page(struct pv_entry *, boolean_t);
    304 static void	pmap_page_remove(struct vm_page *);
    305 
    306 static struct vm_page	*pmap_alloc_ptp(struct pmap *, vaddr_t);
    307 static struct vm_page	*pmap_get_ptp(struct pmap *, vaddr_t);
    308 __inline static void 	 pmap_clearbit(struct vm_page *, unsigned int);
    309 
    310 extern paddr_t physical_start;
    311 extern paddr_t physical_end;
    312 extern unsigned int free_pages;
    313 extern int max_processes;
    314 
    315 vaddr_t virtual_avail;
    316 vaddr_t virtual_end;
    317 vaddr_t pmap_curmaxkvaddr;
    318 
    319 vaddr_t avail_start;
    320 vaddr_t avail_end;
    321 
    322 extern pv_addr_t systempage;
    323 
    324 /* Variables used by the L1 page table queue code */
    325 SIMPLEQ_HEAD(l1pt_queue, l1pt);
    326 static struct l1pt_queue l1pt_static_queue; /* head of our static l1 queue */
    327 static u_int l1pt_static_queue_count;	    /* items in the static l1 queue */
    328 static u_int l1pt_static_create_count;	    /* static l1 items created */
    329 static struct l1pt_queue l1pt_queue;	    /* head of our l1 queue */
    330 static u_int l1pt_queue_count;		    /* items in the l1 queue */
    331 static u_int l1pt_create_count;		    /* stat - L1's create count */
    332 static u_int l1pt_reuse_count;		    /* stat - L1's reused count */
    333 
    334 /* Local function prototypes (not used outside this file) */
    335 void pmap_pinit(struct pmap *);
    336 void pmap_freepagedir(struct pmap *);
    337 
    338 /* Other function prototypes */
    339 extern void bzero_page(vaddr_t);
    340 extern void bcopy_page(vaddr_t, vaddr_t);
    341 
    342 struct l1pt *pmap_alloc_l1pt(void);
    343 static __inline void pmap_map_in_l1(struct pmap *pmap, vaddr_t va,
    344      				    vaddr_t l2pa, unsigned int);
    345 
    346 static pt_entry_t *pmap_map_ptes(struct pmap *);
    347 static void 	   pmap_unmap_ptes(struct pmap *);
    348 
    349 __inline static void pmap_vac_me_harder(struct pmap *, struct vm_page *,
    350 					pt_entry_t *, boolean_t);
    351 static void pmap_vac_me_kpmap(struct pmap *, struct vm_page *,
    352 			      pt_entry_t *, boolean_t);
    353 static void pmap_vac_me_user(struct pmap *, struct vm_page *,
    354 			     pt_entry_t *, boolean_t);
    355 
    356 /*
    357  * real definition of pv_entry.
    358  */
    359 
    360 struct pv_entry {
    361 	struct pv_entry *pv_next;	/* next pv_entry */
    362 	struct pmap     *pv_pmap;	/* pmap where mapping lies */
    363 	vaddr_t         pv_va;		/* virtual address for mapping */
    364 	unsigned int    pv_flags;	/* flags */
    365 	struct vm_page	*pv_ptp;	/* vm_page for the ptp */
    366 };
    367 
    368 /*
    369  * pv_entrys are dynamically allocated in chunks from a single page.
    370  * we keep track of how many pv_entrys are in use for each page and
    371  * we can free pv_entry pages if needed.  there is one lock for the
    372  * entire allocation system.
    373  */
    374 
    375 struct pv_page_info {
    376 	TAILQ_ENTRY(pv_page) pvpi_list;
    377 	struct pv_entry *pvpi_pvfree;
    378 	unsigned int pvpi_nfree;
    379 };
    380 
    381 /*
    382  * number of pv_entry's in a pv_page
    383  * (note: won't work on systems where NPBG isn't a constant)
    384  */
    385 
    386 #define PVE_PER_PVPAGE ((NBPG - sizeof(struct pv_page_info)) / \
    387 			sizeof(struct pv_entry))
    388 
    389 /*
    390  * a pv_page: where pv_entrys are allocated from
    391  */
    392 
    393 struct pv_page {
    394 	struct pv_page_info pvinfo;
    395 	struct pv_entry pvents[PVE_PER_PVPAGE];
    396 };
    397 
    398 #ifdef MYCROFT_HACK
    399 int mycroft_hack = 0;
    400 #endif
    401 
    402 /* Function to set the debug level of the pmap code */
    403 
    404 #ifdef PMAP_DEBUG
    405 void
    406 pmap_debug(int level)
    407 {
    408 	pmap_debug_level = level;
    409 	printf("pmap_debug: level=%d\n", pmap_debug_level);
    410 }
    411 #endif	/* PMAP_DEBUG */
    412 
    413 __inline static boolean_t
    414 pmap_is_curpmap(struct pmap *pmap)
    415 {
    416 
    417 	if ((curproc && curproc->p_vmspace->vm_map.pmap == pmap) ||
    418 	    pmap == pmap_kernel())
    419 		return (TRUE);
    420 
    421 	return (FALSE);
    422 }
    423 
    424 /*
    425  * PTE_SYNC_CURRENT:
    426  *
    427  *	Make sure the pte is flushed to RAM.  If the pmap is
    428  *	not the current pmap, then also evict the pte from
    429  *	any cache lines.
    430  */
    431 #define	PTE_SYNC_CURRENT(pmap, pte)					\
    432 do {									\
    433 	if (pmap_is_curpmap(pmap))					\
    434 		PTE_SYNC(pte);						\
    435 	else								\
    436 		PTE_FLUSH(pte);						\
    437 } while (/*CONSTCOND*/0)
    438 
    439 /*
    440  * PTE_FLUSH_ALT:
    441  *
    442  *	Make sure the pte is not in any cache lines.  We expect
    443  *	this to be used only when a pte has not been modified.
    444  */
    445 #define	PTE_FLUSH_ALT(pmap, pte)					\
    446 do {									\
    447 	if (pmap_is_curpmap(pmap) == 0)					\
    448 		PTE_FLUSH(pte);						\
    449 } while (/*CONSTCOND*/0)
    450 
    451 /*
    452  * p v _ e n t r y   f u n c t i o n s
    453  */
    454 
    455 /*
    456  * pv_entry allocation functions:
    457  *   the main pv_entry allocation functions are:
    458  *     pmap_alloc_pv: allocate a pv_entry structure
    459  *     pmap_free_pv: free one pv_entry
    460  *     pmap_free_pvs: free a list of pv_entrys
    461  *
    462  * the rest are helper functions
    463  */
    464 
    465 /*
    466  * pmap_alloc_pv: inline function to allocate a pv_entry structure
    467  * => we lock pvalloc_lock
    468  * => if we fail, we call out to pmap_alloc_pvpage
    469  * => 3 modes:
    470  *    ALLOCPV_NEED   = we really need a pv_entry, even if we have to steal it
    471  *    ALLOCPV_TRY    = we want a pv_entry, but not enough to steal
    472  *    ALLOCPV_NONEED = we are trying to grow our free list, don't really need
    473  *			one now
    474  *
    475  * "try" is for optional functions like pmap_copy().
    476  */
    477 
    478 __inline static struct pv_entry *
    479 pmap_alloc_pv(struct pmap *pmap, unsigned int mode)
    480 {
    481 	struct pv_page *pvpage;
    482 	struct pv_entry *pv;
    483 
    484 	simple_lock(&pvalloc_lock);
    485 
    486 	pvpage = TAILQ_FIRST(&pv_freepages);
    487 
    488 	if (pvpage != NULL) {
    489 		pvpage->pvinfo.pvpi_nfree--;
    490 		if (pvpage->pvinfo.pvpi_nfree == 0) {
    491 			/* nothing left in this one? */
    492 			TAILQ_REMOVE(&pv_freepages, pvpage, pvinfo.pvpi_list);
    493 		}
    494 		pv = pvpage->pvinfo.pvpi_pvfree;
    495 		KASSERT(pv);
    496 		pvpage->pvinfo.pvpi_pvfree = pv->pv_next;
    497 		pv_nfpvents--;  /* took one from pool */
    498 	} else {
    499 		pv = NULL;		/* need more of them */
    500 	}
    501 
    502 	/*
    503 	 * if below low water mark or we didn't get a pv_entry we try and
    504 	 * create more pv_entrys ...
    505 	 */
    506 
    507 	if (pv_nfpvents < PVE_LOWAT || pv == NULL) {
    508 		if (pv == NULL)
    509 			pv = pmap_alloc_pvpage(pmap, (mode == ALLOCPV_TRY) ?
    510 					       mode : ALLOCPV_NEED);
    511 		else
    512 			(void) pmap_alloc_pvpage(pmap, ALLOCPV_NONEED);
    513 	}
    514 
    515 	simple_unlock(&pvalloc_lock);
    516 	return(pv);
    517 }
    518 
    519 /*
    520  * pmap_alloc_pvpage: maybe allocate a new pvpage
    521  *
    522  * if need_entry is false: try and allocate a new pv_page
    523  * if need_entry is true: try and allocate a new pv_page and return a
    524  *	new pv_entry from it.   if we are unable to allocate a pv_page
    525  *	we make a last ditch effort to steal a pv_page from some other
    526  *	mapping.    if that fails, we panic...
    527  *
    528  * => we assume that the caller holds pvalloc_lock
    529  */
    530 
    531 static struct pv_entry *
    532 pmap_alloc_pvpage(struct pmap *pmap, unsigned int mode)
    533 {
    534 	struct vm_page *pg;
    535 	struct pv_page *pvpage;
    536 	struct pv_entry *pv;
    537 
    538 	/*
    539 	 * if we need_entry and we've got unused pv_pages, allocate from there
    540 	 */
    541 
    542 	pvpage = TAILQ_FIRST(&pv_unusedpgs);
    543 	if (mode != ALLOCPV_NONEED && pvpage != NULL) {
    544 
    545 		/* move it to pv_freepages list */
    546 		TAILQ_REMOVE(&pv_unusedpgs, pvpage, pvinfo.pvpi_list);
    547 		TAILQ_INSERT_HEAD(&pv_freepages, pvpage, pvinfo.pvpi_list);
    548 
    549 		/* allocate a pv_entry */
    550 		pvpage->pvinfo.pvpi_nfree--;	/* can't go to zero */
    551 		pv = pvpage->pvinfo.pvpi_pvfree;
    552 		KASSERT(pv);
    553 		pvpage->pvinfo.pvpi_pvfree = pv->pv_next;
    554 
    555 		pv_nfpvents--;  /* took one from pool */
    556 		return(pv);
    557 	}
    558 
    559 	/*
    560 	 *  see if we've got a cached unmapped VA that we can map a page in.
    561 	 * if not, try to allocate one.
    562 	 */
    563 
    564 
    565 	if (pv_cachedva == 0) {
    566 		int s;
    567 		s = splvm();
    568 		pv_cachedva = uvm_km_kmemalloc(kmem_map, NULL,
    569 		    PAGE_SIZE, UVM_KMF_TRYLOCK|UVM_KMF_VALLOC);
    570 		splx(s);
    571 		if (pv_cachedva == 0) {
    572 			return (NULL);
    573 		}
    574 	}
    575 
    576 	pg = uvm_pagealloc(NULL, pv_cachedva - vm_map_min(kernel_map), NULL,
    577 	    UVM_PGA_USERESERVE);
    578 
    579 	if (pg == NULL)
    580 		return (NULL);
    581 	pg->flags &= ~PG_BUSY;	/* never busy */
    582 
    583 	/*
    584 	 * add a mapping for our new pv_page and free its entrys (save one!)
    585 	 *
    586 	 * NOTE: If we are allocating a PV page for the kernel pmap, the
    587 	 * pmap is already locked!  (...but entering the mapping is safe...)
    588 	 */
    589 
    590 	pmap_kenter_pa(pv_cachedva, VM_PAGE_TO_PHYS(pg),
    591 		VM_PROT_READ|VM_PROT_WRITE);
    592 	pmap_update(pmap_kernel());
    593 	pvpage = (struct pv_page *) pv_cachedva;
    594 	pv_cachedva = 0;
    595 	return (pmap_add_pvpage(pvpage, mode != ALLOCPV_NONEED));
    596 }
    597 
    598 /*
    599  * pmap_add_pvpage: add a pv_page's pv_entrys to the free list
    600  *
    601  * => caller must hold pvalloc_lock
    602  * => if need_entry is true, we allocate and return one pv_entry
    603  */
    604 
    605 static struct pv_entry *
    606 pmap_add_pvpage(struct pv_page *pvp, boolean_t need_entry)
    607 {
    608 	unsigned int tofree, lcv;
    609 
    610 	/* do we need to return one? */
    611 	tofree = (need_entry) ? PVE_PER_PVPAGE - 1 : PVE_PER_PVPAGE;
    612 
    613 	pvp->pvinfo.pvpi_pvfree = NULL;
    614 	pvp->pvinfo.pvpi_nfree = tofree;
    615 	for (lcv = 0 ; lcv < tofree ; lcv++) {
    616 		pvp->pvents[lcv].pv_next = pvp->pvinfo.pvpi_pvfree;
    617 		pvp->pvinfo.pvpi_pvfree = &pvp->pvents[lcv];
    618 	}
    619 	if (need_entry)
    620 		TAILQ_INSERT_TAIL(&pv_freepages, pvp, pvinfo.pvpi_list);
    621 	else
    622 		TAILQ_INSERT_TAIL(&pv_unusedpgs, pvp, pvinfo.pvpi_list);
    623 	pv_nfpvents += tofree;
    624 	return((need_entry) ? &pvp->pvents[lcv] : NULL);
    625 }
    626 
    627 /*
    628  * pmap_free_pv_doit: actually free a pv_entry
    629  *
    630  * => do not call this directly!  instead use either
    631  *    1. pmap_free_pv ==> free a single pv_entry
    632  *    2. pmap_free_pvs => free a list of pv_entrys
    633  * => we must be holding pvalloc_lock
    634  */
    635 
    636 __inline static void
    637 pmap_free_pv_doit(struct pv_entry *pv)
    638 {
    639 	struct pv_page *pvp;
    640 
    641 	pvp = (struct pv_page *) arm_trunc_page((vaddr_t)pv);
    642 	pv_nfpvents++;
    643 	pvp->pvinfo.pvpi_nfree++;
    644 
    645 	/* nfree == 1 => fully allocated page just became partly allocated */
    646 	if (pvp->pvinfo.pvpi_nfree == 1) {
    647 		TAILQ_INSERT_HEAD(&pv_freepages, pvp, pvinfo.pvpi_list);
    648 	}
    649 
    650 	/* free it */
    651 	pv->pv_next = pvp->pvinfo.pvpi_pvfree;
    652 	pvp->pvinfo.pvpi_pvfree = pv;
    653 
    654 	/*
    655 	 * are all pv_page's pv_entry's free?  move it to unused queue.
    656 	 */
    657 
    658 	if (pvp->pvinfo.pvpi_nfree == PVE_PER_PVPAGE) {
    659 		TAILQ_REMOVE(&pv_freepages, pvp, pvinfo.pvpi_list);
    660 		TAILQ_INSERT_HEAD(&pv_unusedpgs, pvp, pvinfo.pvpi_list);
    661 	}
    662 }
    663 
    664 /*
    665  * pmap_free_pv: free a single pv_entry
    666  *
    667  * => we gain the pvalloc_lock
    668  */
    669 
    670 __inline static void
    671 pmap_free_pv(struct pmap *pmap, struct pv_entry *pv)
    672 {
    673 	simple_lock(&pvalloc_lock);
    674 	pmap_free_pv_doit(pv);
    675 
    676 	/*
    677 	 * Can't free the PV page if the PV entries were associated with
    678 	 * the kernel pmap; the pmap is already locked.
    679 	 */
    680 	if (pv_nfpvents > PVE_HIWAT && TAILQ_FIRST(&pv_unusedpgs) != NULL &&
    681 	    pmap != pmap_kernel())
    682 		pmap_free_pvpage();
    683 
    684 	simple_unlock(&pvalloc_lock);
    685 }
    686 
    687 /*
    688  * pmap_free_pvs: free a list of pv_entrys
    689  *
    690  * => we gain the pvalloc_lock
    691  */
    692 
    693 __inline static void
    694 pmap_free_pvs(struct pmap *pmap, struct pv_entry *pvs)
    695 {
    696 	struct pv_entry *nextpv;
    697 
    698 	simple_lock(&pvalloc_lock);
    699 
    700 	for ( /* null */ ; pvs != NULL ; pvs = nextpv) {
    701 		nextpv = pvs->pv_next;
    702 		pmap_free_pv_doit(pvs);
    703 	}
    704 
    705 	/*
    706 	 * Can't free the PV page if the PV entries were associated with
    707 	 * the kernel pmap; the pmap is already locked.
    708 	 */
    709 	if (pv_nfpvents > PVE_HIWAT && TAILQ_FIRST(&pv_unusedpgs) != NULL &&
    710 	    pmap != pmap_kernel())
    711 		pmap_free_pvpage();
    712 
    713 	simple_unlock(&pvalloc_lock);
    714 }
    715 
    716 
    717 /*
    718  * pmap_free_pvpage: try and free an unused pv_page structure
    719  *
    720  * => assume caller is holding the pvalloc_lock and that
    721  *	there is a page on the pv_unusedpgs list
    722  * => if we can't get a lock on the kmem_map we try again later
    723  */
    724 
    725 static void
    726 pmap_free_pvpage(void)
    727 {
    728 	int s;
    729 	struct vm_map *map;
    730 	struct vm_map_entry *dead_entries;
    731 	struct pv_page *pvp;
    732 
    733 	s = splvm(); /* protect kmem_map */
    734 
    735 	pvp = TAILQ_FIRST(&pv_unusedpgs);
    736 
    737 	/*
    738 	 * note: watch out for pv_initpage which is allocated out of
    739 	 * kernel_map rather than kmem_map.
    740 	 */
    741 	if (pvp == pv_initpage)
    742 		map = kernel_map;
    743 	else
    744 		map = kmem_map;
    745 	if (vm_map_lock_try(map)) {
    746 
    747 		/* remove pvp from pv_unusedpgs */
    748 		TAILQ_REMOVE(&pv_unusedpgs, pvp, pvinfo.pvpi_list);
    749 
    750 		/* unmap the page */
    751 		dead_entries = NULL;
    752 		uvm_unmap_remove(map, (vaddr_t)pvp, ((vaddr_t)pvp) + PAGE_SIZE,
    753 		    &dead_entries);
    754 		vm_map_unlock(map);
    755 
    756 		if (dead_entries != NULL)
    757 			uvm_unmap_detach(dead_entries, 0);
    758 
    759 		pv_nfpvents -= PVE_PER_PVPAGE;  /* update free count */
    760 	}
    761 	if (pvp == pv_initpage)
    762 		/* no more initpage, we've freed it */
    763 		pv_initpage = NULL;
    764 
    765 	splx(s);
    766 }
    767 
    768 /*
    769  * main pv_entry manipulation functions:
    770  *   pmap_enter_pv: enter a mapping onto a vm_page list
    771  *   pmap_remove_pv: remove a mappiing from a vm_page list
    772  *
    773  * NOTE: pmap_enter_pv expects to lock the pvh itself
    774  *       pmap_remove_pv expects te caller to lock the pvh before calling
    775  */
    776 
    777 /*
    778  * pmap_enter_pv: enter a mapping onto a vm_page lst
    779  *
    780  * => caller should hold the proper lock on pmap_main_lock
    781  * => caller should have pmap locked
    782  * => we will gain the lock on the vm_page and allocate the new pv_entry
    783  * => caller should adjust ptp's wire_count before calling
    784  * => caller should not adjust pmap's wire_count
    785  */
    786 
    787 __inline static void
    788 pmap_enter_pv(struct vm_page *pg, struct pv_entry *pve, struct pmap *pmap,
    789     vaddr_t va, struct vm_page *ptp, unsigned int flags)
    790 {
    791 	pve->pv_pmap = pmap;
    792 	pve->pv_va = va;
    793 	pve->pv_ptp = ptp;			/* NULL for kernel pmap */
    794 	pve->pv_flags = flags;
    795 	simple_lock(&pg->mdpage.pvh_slock);	/* lock vm_page */
    796 	pve->pv_next = pg->mdpage.pvh_list;	/* add to ... */
    797 	pg->mdpage.pvh_list = pve;		/* ... locked list */
    798 	simple_unlock(&pg->mdpage.pvh_slock);	/* unlock, done! */
    799 	if (pve->pv_flags & PVF_WIRED)
    800 		++pmap->pm_stats.wired_count;
    801 #ifdef PMAP_ALIAS_DEBUG
    802     {
    803 	int s = splhigh();
    804 	if (pve->pv_flags & PVF_WRITE)
    805 		pg->mdpage.rw_mappings++;
    806 	else
    807 		pg->mdpage.ro_mappings++;
    808 	if (pg->mdpage.rw_mappings != 0 &&
    809 	    (pg->mdpage.kro_mappings != 0 || pg->mdpage.krw_mappings != 0)) {
    810 		printf("pmap_enter_pv: rw %u, kro %u, krw %u\n",
    811 		    pg->mdpage.rw_mappings, pg->mdpage.kro_mappings,
    812 		    pg->mdpage.krw_mappings);
    813 	}
    814 	splx(s);
    815     }
    816 #endif /* PMAP_ALIAS_DEBUG */
    817 }
    818 
    819 /*
    820  * pmap_remove_pv: try to remove a mapping from a pv_list
    821  *
    822  * => caller should hold proper lock on pmap_main_lock
    823  * => pmap should be locked
    824  * => caller should hold lock on vm_page [so that attrs can be adjusted]
    825  * => caller should adjust ptp's wire_count and free PTP if needed
    826  * => caller should NOT adjust pmap's wire_count
    827  * => we return the removed pve
    828  */
    829 
    830 __inline static struct pv_entry *
    831 pmap_remove_pv(struct vm_page *pg, struct pmap *pmap, vaddr_t va)
    832 {
    833 	struct pv_entry *pve, **prevptr;
    834 
    835 	prevptr = &pg->mdpage.pvh_list;		/* previous pv_entry pointer */
    836 	pve = *prevptr;
    837 	while (pve) {
    838 		if (pve->pv_pmap == pmap && pve->pv_va == va) {	/* match? */
    839 			*prevptr = pve->pv_next;		/* remove it! */
    840 			if (pve->pv_flags & PVF_WIRED)
    841 			    --pmap->pm_stats.wired_count;
    842 #ifdef PMAP_ALIAS_DEBUG
    843     {
    844 			int s = splhigh();
    845 			if (pve->pv_flags & PVF_WRITE) {
    846 				KASSERT(pg->mdpage.rw_mappings != 0);
    847 				pg->mdpage.rw_mappings--;
    848 			} else {
    849 				KASSERT(pg->mdpage.ro_mappings != 0);
    850 				pg->mdpage.ro_mappings--;
    851 			}
    852 			splx(s);
    853     }
    854 #endif /* PMAP_ALIAS_DEBUG */
    855 			break;
    856 		}
    857 		prevptr = &pve->pv_next;		/* previous pointer */
    858 		pve = pve->pv_next;			/* advance */
    859 	}
    860 	return(pve);				/* return removed pve */
    861 }
    862 
    863 /*
    864  *
    865  * pmap_modify_pv: Update pv flags
    866  *
    867  * => caller should hold lock on vm_page [so that attrs can be adjusted]
    868  * => caller should NOT adjust pmap's wire_count
    869  * => caller must call pmap_vac_me_harder() if writable status of a page
    870  *    may have changed.
    871  * => we return the old flags
    872  *
    873  * Modify a physical-virtual mapping in the pv table
    874  */
    875 
    876 static /* __inline */ u_int
    877 pmap_modify_pv(struct pmap *pmap, vaddr_t va, struct vm_page *pg,
    878     u_int bic_mask, u_int eor_mask)
    879 {
    880 	struct pv_entry *npv;
    881 	u_int flags, oflags;
    882 
    883 	/*
    884 	 * There is at least one VA mapping this page.
    885 	 */
    886 
    887 	for (npv = pg->mdpage.pvh_list; npv; npv = npv->pv_next) {
    888 		if (pmap == npv->pv_pmap && va == npv->pv_va) {
    889 			oflags = npv->pv_flags;
    890 			npv->pv_flags = flags =
    891 			    ((oflags & ~bic_mask) ^ eor_mask);
    892 			if ((flags ^ oflags) & PVF_WIRED) {
    893 				if (flags & PVF_WIRED)
    894 					++pmap->pm_stats.wired_count;
    895 				else
    896 					--pmap->pm_stats.wired_count;
    897 			}
    898 #ifdef PMAP_ALIAS_DEBUG
    899     {
    900 			int s = splhigh();
    901 			if ((flags ^ oflags) & PVF_WRITE) {
    902 				if (flags & PVF_WRITE) {
    903 					pg->mdpage.rw_mappings++;
    904 					pg->mdpage.ro_mappings--;
    905 					if (pg->mdpage.rw_mappings != 0 &&
    906 					    (pg->mdpage.kro_mappings != 0 ||
    907 					     pg->mdpage.krw_mappings != 0)) {
    908 						printf("pmap_modify_pv: rw %u, "
    909 						    "kro %u, krw %u\n",
    910 						    pg->mdpage.rw_mappings,
    911 						    pg->mdpage.kro_mappings,
    912 						    pg->mdpage.krw_mappings);
    913 					}
    914 				} else {
    915 					KASSERT(pg->mdpage.rw_mappings != 0);
    916 					pg->mdpage.rw_mappings--;
    917 					pg->mdpage.ro_mappings++;
    918 				}
    919 			}
    920 			splx(s);
    921     }
    922 #endif /* PMAP_ALIAS_DEBUG */
    923 			return (oflags);
    924 		}
    925 	}
    926 	return (0);
    927 }
    928 
    929 /*
    930  * Map the specified level 2 pagetable into the level 1 page table for
    931  * the given pmap to cover a chunk of virtual address space starting from the
    932  * address specified.
    933  */
    934 #define	PMAP_PTP_SELFREF	0x01
    935 #define	PMAP_PTP_CACHEABLE	0x02
    936 
    937 static __inline void
    938 pmap_map_in_l1(struct pmap *pmap, vaddr_t va, paddr_t l2pa, unsigned int flags)
    939 {
    940 	vaddr_t ptva;
    941 
    942 	KASSERT((va & PD_OFFSET) == 0);		/* XXX KDASSERT */
    943 
    944 	/* Calculate the index into the L1 page table. */
    945 	ptva = va >> L1_S_SHIFT;
    946 
    947 	/* Map page table into the L1. */
    948 	pmap->pm_pdir[ptva + 0] = L1_C_PROTO | (l2pa + 0x000);
    949 	pmap->pm_pdir[ptva + 1] = L1_C_PROTO | (l2pa + 0x400);
    950 	pmap->pm_pdir[ptva + 2] = L1_C_PROTO | (l2pa + 0x800);
    951 	pmap->pm_pdir[ptva + 3] = L1_C_PROTO | (l2pa + 0xc00);
    952 	cpu_dcache_wb_range((vaddr_t) &pmap->pm_pdir[ptva + 0], 16);
    953 
    954 	/* Map the page table into the page table area. */
    955 	if (flags & PMAP_PTP_SELFREF) {
    956 		*((pt_entry_t *)(pmap->pm_vptpt + ptva)) = L2_S_PROTO | l2pa |
    957 		    L2_S_PROT(PTE_KERNEL, VM_PROT_READ|VM_PROT_WRITE) |
    958 		    ((flags & PMAP_PTP_CACHEABLE) ? pte_l2_s_cache_mode : 0);
    959 		PTE_SYNC_CURRENT(pmap, (pt_entry_t *)(pmap->pm_vptpt + ptva));
    960 	}
    961 }
    962 
    963 #if 0
    964 static __inline void
    965 pmap_unmap_in_l1(struct pmap *pmap, vaddr_t va)
    966 {
    967 	vaddr_t ptva;
    968 
    969 	KASSERT((va & PD_OFFSET) == 0);		/* XXX KDASSERT */
    970 
    971 	/* Calculate the index into the L1 page table. */
    972 	ptva = va >> L1_S_SHIFT;
    973 
    974 	/* Unmap page table from the L1. */
    975 	pmap->pm_pdir[ptva + 0] = 0;
    976 	pmap->pm_pdir[ptva + 1] = 0;
    977 	pmap->pm_pdir[ptva + 2] = 0;
    978 	pmap->pm_pdir[ptva + 3] = 0;
    979 	cpu_dcache_wb_range((vaddr_t) &pmap->pm_pdir[ptva + 0], 16);
    980 
    981 	/* Unmap the page table from the page table area. */
    982 	*((pt_entry_t *)(pmap->pm_vptpt + ptva)) = 0;
    983 	PTE_SYNC_CURRENT(pmap, (pt_entry_t *)(pmap->pm_vptpt + ptva));
    984 }
    985 #endif
    986 
    987 /*
    988  *	Used to map a range of physical addresses into kernel
    989  *	virtual address space.
    990  *
    991  *	For now, VM is already on, we only need to map the
    992  *	specified memory.
    993  *
    994  *	XXX This routine should eventually go away; it's only used
    995  *	XXX by machine-dependent crash dump code.
    996  */
    997 vaddr_t
    998 pmap_map(vaddr_t va, paddr_t spa, paddr_t epa, vm_prot_t prot)
    999 {
   1000 	pt_entry_t *pte;
   1001 
   1002 	while (spa < epa) {
   1003 		pte = vtopte(va);
   1004 
   1005 		*pte = L2_S_PROTO | spa |
   1006 		    L2_S_PROT(PTE_KERNEL, prot) | pte_l2_s_cache_mode;
   1007 		PTE_SYNC(pte);
   1008 		cpu_tlb_flushID_SE(va);
   1009 		va += NBPG;
   1010 		spa += NBPG;
   1011 	}
   1012 	pmap_update(pmap_kernel());
   1013 	return(va);
   1014 }
   1015 
   1016 
   1017 /*
   1018  * void pmap_bootstrap(pd_entry_t *kernel_l1pt, pv_addr_t kernel_ptpt)
   1019  *
   1020  * bootstrap the pmap system. This is called from initarm and allows
   1021  * the pmap system to initailise any structures it requires.
   1022  *
   1023  * Currently this sets up the kernel_pmap that is statically allocated
   1024  * and also allocated virtual addresses for certain page hooks.
   1025  * Currently the only one page hook is allocated that is used
   1026  * to zero physical pages of memory.
   1027  * It also initialises the start and end address of the kernel data space.
   1028  */
   1029 
   1030 char *boot_head;
   1031 
   1032 void
   1033 pmap_bootstrap(pd_entry_t *kernel_l1pt, pv_addr_t kernel_ptpt)
   1034 {
   1035 	pt_entry_t *pte;
   1036 
   1037 	pmap_kernel()->pm_pdir = kernel_l1pt;
   1038 	pmap_kernel()->pm_pptpt = kernel_ptpt.pv_pa;
   1039 	pmap_kernel()->pm_vptpt = kernel_ptpt.pv_va;
   1040 	simple_lock_init(&pmap_kernel()->pm_lock);
   1041 	pmap_kernel()->pm_obj.pgops = NULL;
   1042 	TAILQ_INIT(&(pmap_kernel()->pm_obj.memq));
   1043 	pmap_kernel()->pm_obj.uo_npages = 0;
   1044 	pmap_kernel()->pm_obj.uo_refs = 1;
   1045 
   1046 	virtual_avail = KERNEL_VM_BASE;
   1047 	virtual_end = KERNEL_VM_BASE + KERNEL_VM_SIZE;
   1048 
   1049 	/*
   1050 	 * now we allocate the "special" VAs which are used for tmp mappings
   1051 	 * by the pmap (and other modules).  we allocate the VAs by advancing
   1052 	 * virtual_avail (note that there are no pages mapped at these VAs).
   1053 	 * we find the PTE that maps the allocated VA via the linear PTE
   1054 	 * mapping.
   1055 	 */
   1056 
   1057 	pte = ((pt_entry_t *) PTE_BASE) + atop(virtual_avail);
   1058 
   1059 	csrcp = virtual_avail; csrc_pte = pte;
   1060 	virtual_avail += PAGE_SIZE; pte++;
   1061 
   1062 	cdstp = virtual_avail; cdst_pte = pte;
   1063 	virtual_avail += PAGE_SIZE; pte++;
   1064 
   1065 	memhook = (char *) virtual_avail;	/* don't need pte */
   1066 	*pte = 0;
   1067 	virtual_avail += PAGE_SIZE; pte++;
   1068 
   1069 	msgbufaddr = (caddr_t) virtual_avail;	/* don't need pte */
   1070 	virtual_avail += round_page(MSGBUFSIZE);
   1071 	pte += atop(round_page(MSGBUFSIZE));
   1072 
   1073 	/*
   1074 	 * init the static-global locks and global lists.
   1075 	 */
   1076 	spinlockinit(&pmap_main_lock, "pmaplk", 0);
   1077 	simple_lock_init(&pvalloc_lock);
   1078 	simple_lock_init(&pmaps_lock);
   1079 	LIST_INIT(&pmaps);
   1080 	TAILQ_INIT(&pv_freepages);
   1081 	TAILQ_INIT(&pv_unusedpgs);
   1082 
   1083 	/*
   1084 	 * initialize the pmap pool.
   1085 	 */
   1086 
   1087 	pool_init(&pmap_pmap_pool, sizeof(struct pmap), 0, 0, 0, "pmappl",
   1088 		  &pool_allocator_nointr);
   1089 
   1090 	/*
   1091 	 * initialize the PT-PT pool and cache.
   1092 	 */
   1093 
   1094 	pool_init(&pmap_ptpt_pool, PAGE_SIZE, 0, 0, 0, "ptptpl",
   1095 		  &pmap_ptpt_allocator);
   1096 	pool_cache_init(&pmap_ptpt_cache, &pmap_ptpt_pool,
   1097 			pmap_ptpt_ctor, NULL, NULL);
   1098 
   1099 	cpu_dcache_wbinv_all();
   1100 }
   1101 
   1102 /*
   1103  * void pmap_init(void)
   1104  *
   1105  * Initialize the pmap module.
   1106  * Called by vm_init() in vm/vm_init.c in order to initialise
   1107  * any structures that the pmap system needs to map virtual memory.
   1108  */
   1109 
   1110 extern int physmem;
   1111 
   1112 void
   1113 pmap_init(void)
   1114 {
   1115 
   1116 	/*
   1117 	 * Set the available memory vars - These do not map to real memory
   1118 	 * addresses and cannot as the physical memory is fragmented.
   1119 	 * They are used by ps for %mem calculations.
   1120 	 * One could argue whether this should be the entire memory or just
   1121 	 * the memory that is useable in a user process.
   1122 	 */
   1123 	avail_start = 0;
   1124 	avail_end = physmem * NBPG;
   1125 
   1126 	/*
   1127 	 * now we need to free enough pv_entry structures to allow us to get
   1128 	 * the kmem_map/kmem_object allocated and inited (done after this
   1129 	 * function is finished).  to do this we allocate one bootstrap page out
   1130 	 * of kernel_map and use it to provide an initial pool of pv_entry
   1131 	 * structures.   we never free this page.
   1132 	 */
   1133 
   1134 	pv_initpage = (struct pv_page *) uvm_km_alloc(kernel_map, PAGE_SIZE);
   1135 	if (pv_initpage == NULL)
   1136 		panic("pmap_init: pv_initpage");
   1137 	pv_cachedva = 0;   /* a VA we have allocated but not used yet */
   1138 	pv_nfpvents = 0;
   1139 	(void) pmap_add_pvpage(pv_initpage, FALSE);
   1140 
   1141 	pmap_initialized = TRUE;
   1142 
   1143 	/* Initialise our L1 page table queues and counters */
   1144 	SIMPLEQ_INIT(&l1pt_static_queue);
   1145 	l1pt_static_queue_count = 0;
   1146 	l1pt_static_create_count = 0;
   1147 	SIMPLEQ_INIT(&l1pt_queue);
   1148 	l1pt_queue_count = 0;
   1149 	l1pt_create_count = 0;
   1150 	l1pt_reuse_count = 0;
   1151 }
   1152 
   1153 /*
   1154  * pmap_postinit()
   1155  *
   1156  * This routine is called after the vm and kmem subsystems have been
   1157  * initialised. This allows the pmap code to perform any initialisation
   1158  * that can only be done one the memory allocation is in place.
   1159  */
   1160 
   1161 void
   1162 pmap_postinit(void)
   1163 {
   1164 	unsigned int loop;
   1165 	struct l1pt *pt;
   1166 
   1167 #ifdef PMAP_STATIC_L1S
   1168 	for (loop = 0; loop < PMAP_STATIC_L1S; ++loop) {
   1169 #else	/* PMAP_STATIC_L1S */
   1170 	for (loop = 0; loop < max_processes; ++loop) {
   1171 #endif	/* PMAP_STATIC_L1S */
   1172 		/* Allocate a L1 page table */
   1173 		pt = pmap_alloc_l1pt();
   1174 		if (!pt)
   1175 			panic("Cannot allocate static L1 page tables");
   1176 
   1177 		/* Clean it */
   1178 		bzero((void *)pt->pt_va, L1_TABLE_SIZE);
   1179 		pt->pt_flags |= (PTFLAG_STATIC | PTFLAG_CLEAN);
   1180 		/* Add the page table to the queue */
   1181 		SIMPLEQ_INSERT_TAIL(&l1pt_static_queue, pt, pt_queue);
   1182 		++l1pt_static_queue_count;
   1183 		++l1pt_static_create_count;
   1184 	}
   1185 }
   1186 
   1187 
   1188 /*
   1189  * Create and return a physical map.
   1190  *
   1191  * If the size specified for the map is zero, the map is an actual physical
   1192  * map, and may be referenced by the hardware.
   1193  *
   1194  * If the size specified is non-zero, the map will be used in software only,
   1195  * and is bounded by that size.
   1196  */
   1197 
   1198 pmap_t
   1199 pmap_create(void)
   1200 {
   1201 	struct pmap *pmap;
   1202 
   1203 	/*
   1204 	 * Fetch pmap entry from the pool
   1205 	 */
   1206 
   1207 	pmap = pool_get(&pmap_pmap_pool, PR_WAITOK);
   1208 	/* XXX is this really needed! */
   1209 	memset(pmap, 0, sizeof(*pmap));
   1210 
   1211 	simple_lock_init(&pmap->pm_obj.vmobjlock);
   1212 	pmap->pm_obj.pgops = NULL;	/* currently not a mappable object */
   1213 	TAILQ_INIT(&pmap->pm_obj.memq);
   1214 	pmap->pm_obj.uo_npages = 0;
   1215 	pmap->pm_obj.uo_refs = 1;
   1216 	pmap->pm_stats.wired_count = 0;
   1217 	pmap->pm_stats.resident_count = 1;
   1218 	pmap->pm_ptphint = NULL;
   1219 
   1220 	/* Now init the machine part of the pmap */
   1221 	pmap_pinit(pmap);
   1222 	return(pmap);
   1223 }
   1224 
   1225 /*
   1226  * pmap_alloc_l1pt()
   1227  *
   1228  * This routine allocates physical and virtual memory for a L1 page table
   1229  * and wires it.
   1230  * A l1pt structure is returned to describe the allocated page table.
   1231  *
   1232  * This routine is allowed to fail if the required memory cannot be allocated.
   1233  * In this case NULL is returned.
   1234  */
   1235 
   1236 struct l1pt *
   1237 pmap_alloc_l1pt(void)
   1238 {
   1239 	paddr_t pa;
   1240 	vaddr_t va;
   1241 	struct l1pt *pt;
   1242 	int error;
   1243 	struct vm_page *m;
   1244 
   1245 	/* Allocate virtual address space for the L1 page table */
   1246 	va = uvm_km_valloc(kernel_map, L1_TABLE_SIZE);
   1247 	if (va == 0) {
   1248 #ifdef DIAGNOSTIC
   1249 		PDEBUG(0,
   1250 		    printf("pmap: Cannot allocate pageable memory for L1\n"));
   1251 #endif	/* DIAGNOSTIC */
   1252 		return(NULL);
   1253 	}
   1254 
   1255 	/* Allocate memory for the l1pt structure */
   1256 	pt = (struct l1pt *)malloc(sizeof(struct l1pt), M_VMPMAP, M_WAITOK);
   1257 
   1258 	/*
   1259 	 * Allocate pages from the VM system.
   1260 	 */
   1261 	error = uvm_pglistalloc(L1_TABLE_SIZE, physical_start, physical_end,
   1262 	    L1_TABLE_SIZE, 0, &pt->pt_plist, 1, M_WAITOK);
   1263 	if (error) {
   1264 #ifdef DIAGNOSTIC
   1265 		PDEBUG(0,
   1266 		    printf("pmap: Cannot allocate physical mem for L1 (%d)\n",
   1267 		    error));
   1268 #endif	/* DIAGNOSTIC */
   1269 		/* Release the resources we already have claimed */
   1270 		free(pt, M_VMPMAP);
   1271 		uvm_km_free(kernel_map, va, L1_TABLE_SIZE);
   1272 		return(NULL);
   1273 	}
   1274 
   1275 	/* Map our physical pages into our virtual space */
   1276 	pt->pt_va = va;
   1277 	m = TAILQ_FIRST(&pt->pt_plist);
   1278 	while (m && va < (pt->pt_va + L1_TABLE_SIZE)) {
   1279 		pa = VM_PAGE_TO_PHYS(m);
   1280 
   1281 		pmap_kenter_pa(va, pa, VM_PROT_READ|VM_PROT_WRITE);
   1282 
   1283 		va += NBPG;
   1284 		m = m->pageq.tqe_next;
   1285 	}
   1286 
   1287 #ifdef DIAGNOSTIC
   1288 	if (m)
   1289 		panic("pmap_alloc_l1pt: pglist not empty");
   1290 #endif	/* DIAGNOSTIC */
   1291 
   1292 	pt->pt_flags = 0;
   1293 	return(pt);
   1294 }
   1295 
   1296 /*
   1297  * Free a L1 page table previously allocated with pmap_alloc_l1pt().
   1298  */
   1299 static void
   1300 pmap_free_l1pt(struct l1pt *pt)
   1301 {
   1302 	/* Separate the physical memory for the virtual space */
   1303 	pmap_kremove(pt->pt_va, L1_TABLE_SIZE);
   1304 	pmap_update(pmap_kernel());
   1305 
   1306 	/* Return the physical memory */
   1307 	uvm_pglistfree(&pt->pt_plist);
   1308 
   1309 	/* Free the virtual space */
   1310 	uvm_km_free(kernel_map, pt->pt_va, L1_TABLE_SIZE);
   1311 
   1312 	/* Free the l1pt structure */
   1313 	free(pt, M_VMPMAP);
   1314 }
   1315 
   1316 /*
   1317  * pmap_ptpt_page_alloc:
   1318  *
   1319  *	Back-end page allocator for the PT-PT pool.
   1320  */
   1321 static void *
   1322 pmap_ptpt_page_alloc(struct pool *pp, int flags)
   1323 {
   1324 	struct vm_page *pg;
   1325 	pt_entry_t *pte;
   1326 	vaddr_t va;
   1327 
   1328 	/* XXX PR_WAITOK? */
   1329 	va = uvm_km_valloc(kernel_map, L2_TABLE_SIZE);
   1330 	if (va == 0)
   1331 		return (NULL);
   1332 
   1333 	for (;;) {
   1334 		pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_ZERO);
   1335 		if (pg != NULL)
   1336 			break;
   1337 		if ((flags & PR_WAITOK) == 0) {
   1338 			uvm_km_free(kernel_map, va, L2_TABLE_SIZE);
   1339 			return (NULL);
   1340 		}
   1341 		uvm_wait("pmap_ptpt");
   1342 	}
   1343 
   1344 	pte = vtopte(va);
   1345 	KDASSERT(pmap_pte_v(pte) == 0);
   1346 
   1347 	*pte = L2_S_PROTO | VM_PAGE_TO_PHYS(pg) |
   1348 	     L2_S_PROT(PTE_KERNEL, VM_PROT_READ|VM_PROT_WRITE);
   1349 	PTE_SYNC(pte);
   1350 #ifdef PMAP_ALIAS_DEBUG
   1351     {
   1352 	int s = splhigh();
   1353 	pg->mdpage.krw_mappings++;
   1354 	splx(s);
   1355     }
   1356 #endif /* PMAP_ALIAS_DEBUG */
   1357 
   1358 	return ((void *) va);
   1359 }
   1360 
   1361 /*
   1362  * pmap_ptpt_page_free:
   1363  *
   1364  *	Back-end page free'er for the PT-PT pool.
   1365  */
   1366 static void
   1367 pmap_ptpt_page_free(struct pool *pp, void *v)
   1368 {
   1369 	vaddr_t va = (vaddr_t) v;
   1370 	paddr_t pa;
   1371 
   1372 	pa = vtophys(va);
   1373 
   1374 	pmap_kremove(va, L2_TABLE_SIZE);
   1375 	pmap_update(pmap_kernel());
   1376 
   1377 	uvm_pagefree(PHYS_TO_VM_PAGE(pa));
   1378 
   1379 	uvm_km_free(kernel_map, va, L2_TABLE_SIZE);
   1380 }
   1381 
   1382 /*
   1383  * pmap_ptpt_ctor:
   1384  *
   1385  *	Constructor for the PT-PT cache.
   1386  */
   1387 static int
   1388 pmap_ptpt_ctor(void *arg, void *object, int flags)
   1389 {
   1390 	caddr_t vptpt = object;
   1391 
   1392 	/* Page is already zero'd. */
   1393 
   1394 	/*
   1395 	 * Map in kernel PTs.
   1396 	 *
   1397 	 * XXX THIS IS CURRENTLY DONE AS UNCACHED MEMORY ACCESS.
   1398 	 */
   1399 	memcpy(vptpt + ((L1_TABLE_SIZE - KERNEL_PD_SIZE) >> 2),
   1400 	       (char *)(PTE_BASE + (PTE_BASE >> (PGSHIFT - 2)) +
   1401 			((L1_TABLE_SIZE - KERNEL_PD_SIZE) >> 2)),
   1402 	       (KERNEL_PD_SIZE >> 2));
   1403 
   1404 	return (0);
   1405 }
   1406 
   1407 /*
   1408  * Allocate a page directory.
   1409  * This routine will either allocate a new page directory from the pool
   1410  * of L1 page tables currently held by the kernel or it will allocate
   1411  * a new one via pmap_alloc_l1pt().
   1412  * It will then initialise the l1 page table for use.
   1413  */
   1414 static int
   1415 pmap_allocpagedir(struct pmap *pmap)
   1416 {
   1417 	vaddr_t vptpt;
   1418 	struct l1pt *pt;
   1419 	u_int gen;
   1420 
   1421 	PDEBUG(0, printf("pmap_allocpagedir(%p)\n", pmap));
   1422 
   1423 	/* Do we have any spare L1's lying around ? */
   1424 	if (l1pt_static_queue_count) {
   1425 		--l1pt_static_queue_count;
   1426 		pt = SIMPLEQ_FIRST(&l1pt_static_queue);
   1427 		SIMPLEQ_REMOVE_HEAD(&l1pt_static_queue, pt_queue);
   1428 	} else if (l1pt_queue_count) {
   1429 		--l1pt_queue_count;
   1430 		pt = SIMPLEQ_FIRST(&l1pt_queue);
   1431 		SIMPLEQ_REMOVE_HEAD(&l1pt_queue, pt_queue);
   1432 		++l1pt_reuse_count;
   1433 	} else {
   1434 		pt = pmap_alloc_l1pt();
   1435 		if (!pt)
   1436 			return(ENOMEM);
   1437 		++l1pt_create_count;
   1438 	}
   1439 
   1440 	/* Store the pointer to the l1 descriptor in the pmap. */
   1441 	pmap->pm_l1pt = pt;
   1442 
   1443 	/* Store the virtual address of the l1 in the pmap. */
   1444 	pmap->pm_pdir = (pd_entry_t *)pt->pt_va;
   1445 
   1446 	/* Clean the L1 if it is dirty */
   1447 	if (!(pt->pt_flags & PTFLAG_CLEAN)) {
   1448 		bzero((void *)pmap->pm_pdir, (L1_TABLE_SIZE - KERNEL_PD_SIZE));
   1449 		cpu_dcache_wb_range((vaddr_t) pmap->pm_pdir,
   1450 		    (L1_TABLE_SIZE - KERNEL_PD_SIZE));
   1451 	}
   1452 
   1453 	/* Allocate a page table to map all the page tables for this pmap */
   1454 	KASSERT(pmap->pm_vptpt == 0);
   1455 
   1456  try_again:
   1457 	gen = pmap_ptpt_cache_generation;
   1458 	vptpt = (vaddr_t) pool_cache_get(&pmap_ptpt_cache, PR_WAITOK);
   1459 	if (vptpt == NULL) {
   1460 		PDEBUG(0, printf("pmap_alloc_pagedir: no KVA for PTPT\n"));
   1461 		pmap_freepagedir(pmap);
   1462 		return (ENOMEM);
   1463 	}
   1464 
   1465 	/* need to lock this all up for growkernel */
   1466 	simple_lock(&pmaps_lock);
   1467 
   1468 	if (gen != pmap_ptpt_cache_generation) {
   1469 		simple_unlock(&pmaps_lock);
   1470 		pool_cache_destruct_object(&pmap_ptpt_cache, (void *) vptpt);
   1471 		goto try_again;
   1472 	}
   1473 
   1474 	pmap->pm_vptpt = vptpt;
   1475 	pmap->pm_pptpt = vtophys(vptpt);
   1476 
   1477 	/* Duplicate the kernel mappings. */
   1478 	bcopy((char *)pmap_kernel()->pm_pdir + (L1_TABLE_SIZE - KERNEL_PD_SIZE),
   1479 		(char *)pmap->pm_pdir + (L1_TABLE_SIZE - KERNEL_PD_SIZE),
   1480 		KERNEL_PD_SIZE);
   1481 	cpu_dcache_wb_range((vaddr_t)pmap->pm_pdir +
   1482 	    (L1_TABLE_SIZE - KERNEL_PD_SIZE), KERNEL_PD_SIZE);
   1483 
   1484 	/* Wire in this page table */
   1485 	pmap_map_in_l1(pmap, PTE_BASE, pmap->pm_pptpt, PMAP_PTP_SELFREF);
   1486 
   1487 	pt->pt_flags &= ~PTFLAG_CLEAN;	/* L1 is dirty now */
   1488 
   1489 	LIST_INSERT_HEAD(&pmaps, pmap, pm_list);
   1490 	simple_unlock(&pmaps_lock);
   1491 
   1492 	return(0);
   1493 }
   1494 
   1495 
   1496 /*
   1497  * Initialize a preallocated and zeroed pmap structure,
   1498  * such as one in a vmspace structure.
   1499  */
   1500 
   1501 void
   1502 pmap_pinit(struct pmap *pmap)
   1503 {
   1504 	unsigned int backoff = 6;
   1505 	unsigned int retry = 10;
   1506 
   1507 	PDEBUG(0, printf("pmap_pinit(%p)\n", pmap));
   1508 
   1509 	/* Keep looping until we succeed in allocating a page directory */
   1510 	while (pmap_allocpagedir(pmap) != 0) {
   1511 		/*
   1512 		 * Ok we failed to allocate a suitable block of memory for an
   1513 		 * L1 page table. This means that either:
   1514 		 * 1. 16KB of virtual address space could not be allocated
   1515 		 * 2. 16KB of physically contiguous memory on a 16KB boundary
   1516 		 *    could not be allocated.
   1517 		 *
   1518 		 * Since we cannot fail we will sleep for a while and try
   1519 		 * again.
   1520 		 *
   1521 		 * Searching for a suitable L1 PT is expensive:
   1522 		 * to avoid hogging the system when memory is really
   1523 		 * scarce, use an exponential back-off so that
   1524 		 * eventually we won't retry more than once every 8
   1525 		 * seconds.  This should allow other processes to run
   1526 		 * to completion and free up resources.
   1527 		 */
   1528 		(void) ltsleep(&lbolt, PVM, "l1ptwait", (hz << 3) >> backoff,
   1529 		    NULL);
   1530 		if (--retry == 0) {
   1531 			retry = 10;
   1532 			if (backoff)
   1533 				--backoff;
   1534 		}
   1535 	}
   1536 
   1537 	if (vector_page < KERNEL_BASE) {
   1538 		/*
   1539 		 * Map the vector page.  This will also allocate and map
   1540 		 * an L2 table for it.
   1541 		 */
   1542 		pmap_enter(pmap, vector_page, systempage.pv_pa,
   1543 		    VM_PROT_READ, VM_PROT_READ | PMAP_WIRED);
   1544 		pmap_update(pmap);
   1545 	}
   1546 }
   1547 
   1548 void
   1549 pmap_freepagedir(struct pmap *pmap)
   1550 {
   1551 	/* Free the memory used for the page table mapping */
   1552 	if (pmap->pm_vptpt != 0) {
   1553 		/*
   1554 		 * XXX Objects freed to a pool cache must be in constructed
   1555 		 * XXX form when freed, but we don't free page tables as we
   1556 		 * XXX go, so we need to zap the mappings here.
   1557 		 *
   1558 		 * XXX THIS IS CURRENTLY DONE AS UNCACHED MEMORY ACCESS.
   1559 		 */
   1560 		memset((caddr_t) pmap->pm_vptpt, 0,
   1561 		       ((L1_TABLE_SIZE - KERNEL_PD_SIZE) >> 2));
   1562 		pool_cache_put(&pmap_ptpt_cache, (void *) pmap->pm_vptpt);
   1563 	}
   1564 
   1565 	/* junk the L1 page table */
   1566 	if (pmap->pm_l1pt->pt_flags & PTFLAG_STATIC) {
   1567 		/* Add the page table to the queue */
   1568 		SIMPLEQ_INSERT_TAIL(&l1pt_static_queue,
   1569 				    pmap->pm_l1pt, pt_queue);
   1570 		++l1pt_static_queue_count;
   1571 	} else if (l1pt_queue_count < 8) {
   1572 		/* Add the page table to the queue */
   1573 		SIMPLEQ_INSERT_TAIL(&l1pt_queue, pmap->pm_l1pt, pt_queue);
   1574 		++l1pt_queue_count;
   1575 	} else
   1576 		pmap_free_l1pt(pmap->pm_l1pt);
   1577 }
   1578 
   1579 /*
   1580  * Retire the given physical map from service.
   1581  * Should only be called if the map contains no valid mappings.
   1582  */
   1583 
   1584 void
   1585 pmap_destroy(struct pmap *pmap)
   1586 {
   1587 	struct vm_page *page;
   1588 	unsigned int count;
   1589 
   1590 	if (pmap == NULL)
   1591 		return;
   1592 
   1593 	PDEBUG(0, printf("pmap_destroy(%p)\n", pmap));
   1594 
   1595 	/*
   1596 	 * Drop reference count
   1597 	 */
   1598 	simple_lock(&pmap->pm_obj.vmobjlock);
   1599 	count = --pmap->pm_obj.uo_refs;
   1600 	simple_unlock(&pmap->pm_obj.vmobjlock);
   1601 	if (count > 0) {
   1602 		return;
   1603 	}
   1604 
   1605 	/*
   1606 	 * reference count is zero, free pmap resources and then free pmap.
   1607 	 */
   1608 
   1609 	/*
   1610 	 * remove it from global list of pmaps
   1611 	 */
   1612 
   1613 	simple_lock(&pmaps_lock);
   1614 	LIST_REMOVE(pmap, pm_list);
   1615 	simple_unlock(&pmaps_lock);
   1616 
   1617 	if (vector_page < KERNEL_BASE) {
   1618 		/* Remove the vector page mapping */
   1619 		pmap_remove(pmap, vector_page, vector_page + NBPG);
   1620 		pmap_update(pmap);
   1621 	}
   1622 
   1623 	/*
   1624 	 * Free any page tables still mapped
   1625 	 * This is only temporay until pmap_enter can count the number
   1626 	 * of mappings made in a page table. Then pmap_remove() can
   1627 	 * reduce the count and free the pagetable when the count
   1628 	 * reaches zero.  Note that entries in this list should match the
   1629 	 * contents of the ptpt, however this is faster than walking a 1024
   1630 	 * entries looking for pt's
   1631 	 * taken from i386 pmap.c
   1632 	 */
   1633 	/*
   1634 	 * vmobjlock must be held while freeing pages
   1635 	 */
   1636 	simple_lock(&pmap->pm_obj.vmobjlock);
   1637 	while ((page = TAILQ_FIRST(&pmap->pm_obj.memq)) != NULL) {
   1638 		KASSERT((page->flags & PG_BUSY) == 0);
   1639 
   1640 		/* Freeing a PT page?  The contents are a throw-away. */
   1641 		KASSERT((page->offset & PD_OFFSET) == 0);/* XXX KDASSERT */
   1642 		cpu_dcache_inv_range((vaddr_t)vtopte(page->offset), PAGE_SIZE);
   1643 
   1644 		page->wire_count = 0;
   1645 		uvm_pagefree(page);
   1646 	}
   1647 	simple_unlock(&pmap->pm_obj.vmobjlock);
   1648 
   1649 	/* Free the page dir */
   1650 	pmap_freepagedir(pmap);
   1651 
   1652 	/* return the pmap to the pool */
   1653 	pool_put(&pmap_pmap_pool, pmap);
   1654 }
   1655 
   1656 
   1657 /*
   1658  * void pmap_reference(struct pmap *pmap)
   1659  *
   1660  * Add a reference to the specified pmap.
   1661  */
   1662 
   1663 void
   1664 pmap_reference(struct pmap *pmap)
   1665 {
   1666 	if (pmap == NULL)
   1667 		return;
   1668 
   1669 	simple_lock(&pmap->pm_lock);
   1670 	pmap->pm_obj.uo_refs++;
   1671 	simple_unlock(&pmap->pm_lock);
   1672 }
   1673 
   1674 /*
   1675  * void pmap_virtual_space(vaddr_t *start, vaddr_t *end)
   1676  *
   1677  * Return the start and end addresses of the kernel's virtual space.
   1678  * These values are setup in pmap_bootstrap and are updated as pages
   1679  * are allocated.
   1680  */
   1681 
   1682 void
   1683 pmap_virtual_space(vaddr_t *start, vaddr_t *end)
   1684 {
   1685 	*start = virtual_avail;
   1686 	*end = virtual_end;
   1687 }
   1688 
   1689 /*
   1690  * Activate the address space for the specified process.  If the process
   1691  * is the current process, load the new MMU context.
   1692  */
   1693 void
   1694 pmap_activate(struct lwp *l)
   1695 {
   1696 	struct pmap *pmap = l->l_proc->p_vmspace->vm_map.pmap;
   1697 	struct pcb *pcb = &l->l_addr->u_pcb;
   1698 
   1699 	(void) pmap_extract(pmap_kernel(), (vaddr_t)pmap->pm_pdir,
   1700 	    (paddr_t *)&pcb->pcb_pagedir);
   1701 
   1702 	PDEBUG(0, printf("pmap_activate: l=%p pmap=%p pcb=%p pdir=%p l1=%p\n",
   1703 	    l, pmap, pcb, pmap->pm_pdir, pcb->pcb_pagedir));
   1704 
   1705 	if (l == curlwp) {
   1706 		PDEBUG(0, printf("pmap_activate: setting TTB\n"));
   1707 		setttb((u_int)pcb->pcb_pagedir);
   1708 	}
   1709 }
   1710 
   1711 /*
   1712  * Deactivate the address space of the specified process.
   1713  */
   1714 void
   1715 pmap_deactivate(struct lwp *l)
   1716 {
   1717 }
   1718 
   1719 /*
   1720  * Perform any deferred pmap operations.
   1721  */
   1722 void
   1723 pmap_update(struct pmap *pmap)
   1724 {
   1725 
   1726 	/*
   1727 	 * We haven't deferred any pmap operations, but we do need to
   1728 	 * make sure TLB/cache operations have completed.
   1729 	 */
   1730 	cpu_cpwait();
   1731 }
   1732 
   1733 /*
   1734  * pmap_clean_page()
   1735  *
   1736  * This is a local function used to work out the best strategy to clean
   1737  * a single page referenced by its entry in the PV table. It's used by
   1738  * pmap_copy_page, pmap_zero page and maybe some others later on.
   1739  *
   1740  * Its policy is effectively:
   1741  *  o If there are no mappings, we don't bother doing anything with the cache.
   1742  *  o If there is one mapping, we clean just that page.
   1743  *  o If there are multiple mappings, we clean the entire cache.
   1744  *
   1745  * So that some functions can be further optimised, it returns 0 if it didn't
   1746  * clean the entire cache, or 1 if it did.
   1747  *
   1748  * XXX One bug in this routine is that if the pv_entry has a single page
   1749  * mapped at 0x00000000 a whole cache clean will be performed rather than
   1750  * just the 1 page. Since this should not occur in everyday use and if it does
   1751  * it will just result in not the most efficient clean for the page.
   1752  */
   1753 static int
   1754 pmap_clean_page(struct pv_entry *pv, boolean_t is_src)
   1755 {
   1756 	struct pmap *pmap;
   1757 	struct pv_entry *npv;
   1758 	boolean_t cache_needs_cleaning = FALSE;
   1759 	vaddr_t page_to_clean = 0;
   1760 
   1761 	if (pv == NULL) {
   1762 		/* nothing mapped in so nothing to flush */
   1763 		return (0);
   1764 	}
   1765 
   1766 	/*
   1767 	 * Since we flush the cache each time we change curlwp, we
   1768 	 * only need to flush the page if it is in the current pmap.
   1769 	 */
   1770 	if (curproc)
   1771 		pmap = curproc->p_vmspace->vm_map.pmap;
   1772 	else
   1773 		pmap = pmap_kernel();
   1774 
   1775 	for (npv = pv; npv; npv = npv->pv_next) {
   1776 		if (npv->pv_pmap == pmap) {
   1777 			/*
   1778 			 * The page is mapped non-cacheable in
   1779 			 * this map.  No need to flush the cache.
   1780 			 */
   1781 			if (npv->pv_flags & PVF_NC) {
   1782 #ifdef DIAGNOSTIC
   1783 				if (cache_needs_cleaning)
   1784 					panic("pmap_clean_page: "
   1785 					    "cache inconsistency");
   1786 #endif
   1787 				break;
   1788 			} else if (is_src && (npv->pv_flags & PVF_WRITE) == 0)
   1789 				continue;
   1790 			if (cache_needs_cleaning) {
   1791 				page_to_clean = 0;
   1792 				break;
   1793 			} else
   1794 				page_to_clean = npv->pv_va;
   1795 			cache_needs_cleaning = TRUE;
   1796 		}
   1797 	}
   1798 
   1799 	if (page_to_clean) {
   1800 		/*
   1801 		 * XXX If is_src, we really only need to write-back,
   1802 		 * XXX not invalidate, too.  Investigate further.
   1803 		 * XXX --thorpej (at) netbsd.org
   1804 		 */
   1805 		cpu_idcache_wbinv_range(page_to_clean, NBPG);
   1806 	} else if (cache_needs_cleaning) {
   1807 		cpu_idcache_wbinv_all();
   1808 		return (1);
   1809 	}
   1810 	return (0);
   1811 }
   1812 
   1813 /*
   1814  * pmap_zero_page()
   1815  *
   1816  * Zero a given physical page by mapping it at a page hook point.
   1817  * In doing the zero page op, the page we zero is mapped cachable, as with
   1818  * StrongARM accesses to non-cached pages are non-burst making writing
   1819  * _any_ bulk data very slow.
   1820  */
   1821 #if ARM_MMU_GENERIC == 1
   1822 void
   1823 pmap_zero_page_generic(paddr_t phys)
   1824 {
   1825 #ifdef DEBUG
   1826 	struct vm_page *pg = PHYS_TO_VM_PAGE(phys);
   1827 
   1828 	if (pg->mdpage.pvh_list != NULL)
   1829 		panic("pmap_zero_page: page has mappings");
   1830 #endif
   1831 
   1832 	KDASSERT((phys & PGOFSET) == 0);
   1833 
   1834 	/*
   1835 	 * Hook in the page, zero it, and purge the cache for that
   1836 	 * zeroed page. Invalidate the TLB as needed.
   1837 	 */
   1838 	*cdst_pte = L2_S_PROTO | phys |
   1839 	    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) | pte_l2_s_cache_mode;
   1840 	PTE_SYNC(cdst_pte);
   1841 	cpu_tlb_flushD_SE(cdstp);
   1842 	cpu_cpwait();
   1843 	bzero_page(cdstp);
   1844 	cpu_dcache_wbinv_range(cdstp, NBPG);
   1845 }
   1846 #endif /* ARM_MMU_GENERIC == 1 */
   1847 
   1848 #if ARM_MMU_XSCALE == 1
   1849 void
   1850 pmap_zero_page_xscale(paddr_t phys)
   1851 {
   1852 #ifdef DEBUG
   1853 	struct vm_page *pg = PHYS_TO_VM_PAGE(phys);
   1854 
   1855 	if (pg->mdpage.pvh_list != NULL)
   1856 		panic("pmap_zero_page: page has mappings");
   1857 #endif
   1858 
   1859 	KDASSERT((phys & PGOFSET) == 0);
   1860 
   1861 	/*
   1862 	 * Hook in the page, zero it, and purge the cache for that
   1863 	 * zeroed page. Invalidate the TLB as needed.
   1864 	 */
   1865 	*cdst_pte = L2_S_PROTO | phys |
   1866 	    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) |
   1867 	    L2_C | L2_XSCALE_T_TEX(TEX_XSCALE_X);	/* mini-data */
   1868 	PTE_SYNC(cdst_pte);
   1869 	cpu_tlb_flushD_SE(cdstp);
   1870 	cpu_cpwait();
   1871 	bzero_page(cdstp);
   1872 	xscale_cache_clean_minidata();
   1873 }
   1874 #endif /* ARM_MMU_XSCALE == 1 */
   1875 
   1876 /* pmap_pageidlezero()
   1877  *
   1878  * The same as above, except that we assume that the page is not
   1879  * mapped.  This means we never have to flush the cache first.  Called
   1880  * from the idle loop.
   1881  */
   1882 boolean_t
   1883 pmap_pageidlezero(paddr_t phys)
   1884 {
   1885 	unsigned int i;
   1886 	int *ptr;
   1887 	boolean_t rv = TRUE;
   1888 #ifdef DEBUG
   1889 	struct vm_page *pg;
   1890 
   1891 	pg = PHYS_TO_VM_PAGE(phys);
   1892 	if (pg->mdpage.pvh_list != NULL)
   1893 		panic("pmap_pageidlezero: page has mappings");
   1894 #endif
   1895 
   1896 	KDASSERT((phys & PGOFSET) == 0);
   1897 
   1898 	/*
   1899 	 * Hook in the page, zero it, and purge the cache for that
   1900 	 * zeroed page. Invalidate the TLB as needed.
   1901 	 */
   1902 	*cdst_pte = L2_S_PROTO | phys |
   1903 	    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) | pte_l2_s_cache_mode;
   1904 	PTE_SYNC(cdst_pte);
   1905 	cpu_tlb_flushD_SE(cdstp);
   1906 	cpu_cpwait();
   1907 
   1908 	for (i = 0, ptr = (int *)cdstp;
   1909 			i < (NBPG / sizeof(int)); i++) {
   1910 		if (sched_whichqs != 0) {
   1911 			/*
   1912 			 * A process has become ready.  Abort now,
   1913 			 * so we don't keep it waiting while we
   1914 			 * do slow memory access to finish this
   1915 			 * page.
   1916 			 */
   1917 			rv = FALSE;
   1918 			break;
   1919 		}
   1920 		*ptr++ = 0;
   1921 	}
   1922 
   1923 	if (rv)
   1924 		/*
   1925 		 * if we aborted we'll rezero this page again later so don't
   1926 		 * purge it unless we finished it
   1927 		 */
   1928 		cpu_dcache_wbinv_range(cdstp, NBPG);
   1929 	return (rv);
   1930 }
   1931 
   1932 /*
   1933  * pmap_copy_page()
   1934  *
   1935  * Copy one physical page into another, by mapping the pages into
   1936  * hook points. The same comment regarding cachability as in
   1937  * pmap_zero_page also applies here.
   1938  */
   1939 #if ARM_MMU_GENERIC == 1
   1940 void
   1941 pmap_copy_page_generic(paddr_t src, paddr_t dst)
   1942 {
   1943 	struct vm_page *src_pg = PHYS_TO_VM_PAGE(src);
   1944 #ifdef DEBUG
   1945 	struct vm_page *dst_pg = PHYS_TO_VM_PAGE(dst);
   1946 
   1947 	if (dst_pg->mdpage.pvh_list != NULL)
   1948 		panic("pmap_copy_page: dst page has mappings");
   1949 #endif
   1950 
   1951 	KDASSERT((src & PGOFSET) == 0);
   1952 	KDASSERT((dst & PGOFSET) == 0);
   1953 
   1954 	/*
   1955 	 * Clean the source page.  Hold the source page's lock for
   1956 	 * the duration of the copy so that no other mappings can
   1957 	 * be created while we have a potentially aliased mapping.
   1958 	 */
   1959 	simple_lock(&src_pg->mdpage.pvh_slock);
   1960 	(void) pmap_clean_page(src_pg->mdpage.pvh_list, TRUE);
   1961 
   1962 	/*
   1963 	 * Map the pages into the page hook points, copy them, and purge
   1964 	 * the cache for the appropriate page. Invalidate the TLB
   1965 	 * as required.
   1966 	 */
   1967 	*csrc_pte = L2_S_PROTO | src |
   1968 	    L2_S_PROT(PTE_KERNEL, VM_PROT_READ) | pte_l2_s_cache_mode;
   1969 	PTE_SYNC(csrc_pte);
   1970 	*cdst_pte = L2_S_PROTO | dst |
   1971 	    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) | pte_l2_s_cache_mode;
   1972 	PTE_SYNC(cdst_pte);
   1973 	cpu_tlb_flushD_SE(csrcp);
   1974 	cpu_tlb_flushD_SE(cdstp);
   1975 	cpu_cpwait();
   1976 	bcopy_page(csrcp, cdstp);
   1977 	cpu_dcache_inv_range(csrcp, NBPG);
   1978 	simple_unlock(&src_pg->mdpage.pvh_slock); /* cache is safe again */
   1979 	cpu_dcache_wbinv_range(cdstp, NBPG);
   1980 }
   1981 #endif /* ARM_MMU_GENERIC == 1 */
   1982 
   1983 #if ARM_MMU_XSCALE == 1
   1984 void
   1985 pmap_copy_page_xscale(paddr_t src, paddr_t dst)
   1986 {
   1987 	struct vm_page *src_pg = PHYS_TO_VM_PAGE(src);
   1988 #ifdef DEBUG
   1989 	struct vm_page *dst_pg = PHYS_TO_VM_PAGE(dst);
   1990 
   1991 	if (dst_pg->mdpage.pvh_list != NULL)
   1992 		panic("pmap_copy_page: dst page has mappings");
   1993 #endif
   1994 
   1995 	KDASSERT((src & PGOFSET) == 0);
   1996 	KDASSERT((dst & PGOFSET) == 0);
   1997 
   1998 	/*
   1999 	 * Clean the source page.  Hold the source page's lock for
   2000 	 * the duration of the copy so that no other mappings can
   2001 	 * be created while we have a potentially aliased mapping.
   2002 	 */
   2003 	simple_lock(&src_pg->mdpage.pvh_slock);
   2004 	(void) pmap_clean_page(src_pg->mdpage.pvh_list, TRUE);
   2005 
   2006 	/*
   2007 	 * Map the pages into the page hook points, copy them, and purge
   2008 	 * the cache for the appropriate page. Invalidate the TLB
   2009 	 * as required.
   2010 	 */
   2011 	*csrc_pte = L2_S_PROTO | src |
   2012 	    L2_S_PROT(PTE_KERNEL, VM_PROT_READ) |
   2013 	    L2_C | L2_XSCALE_T_TEX(TEX_XSCALE_X);	/* mini-data */
   2014 	PTE_SYNC(csrc_pte);
   2015 	*cdst_pte = L2_S_PROTO | dst |
   2016 	    L2_S_PROT(PTE_KERNEL, VM_PROT_WRITE) |
   2017 	    L2_C | L2_XSCALE_T_TEX(TEX_XSCALE_X);	/* mini-data */
   2018 	PTE_SYNC(cdst_pte);
   2019 	cpu_tlb_flushD_SE(csrcp);
   2020 	cpu_tlb_flushD_SE(cdstp);
   2021 	cpu_cpwait();
   2022 	bcopy_page(csrcp, cdstp);
   2023 	simple_unlock(&src_pg->mdpage.pvh_slock); /* cache is safe again */
   2024 	xscale_cache_clean_minidata();
   2025 }
   2026 #endif /* ARM_MMU_XSCALE == 1 */
   2027 
   2028 #if 0
   2029 void
   2030 pmap_pte_addref(struct pmap *pmap, vaddr_t va)
   2031 {
   2032 	pd_entry_t *pde;
   2033 	paddr_t pa;
   2034 	struct vm_page *m;
   2035 
   2036 	if (pmap == pmap_kernel())
   2037 		return;
   2038 
   2039 	pde = pmap_pde(pmap, va & PD_FRAME);
   2040 	pa = pmap_pte_pa(pde);
   2041 	m = PHYS_TO_VM_PAGE(pa);
   2042 	m->wire_count++;
   2043 #ifdef MYCROFT_HACK
   2044 	printf("addref pmap=%p va=%08lx pde=%p pa=%08lx m=%p wire=%d\n",
   2045 	    pmap, va, pde, pa, m, m->wire_count);
   2046 #endif
   2047 }
   2048 
   2049 void
   2050 pmap_pte_delref(struct pmap *pmap, vaddr_t va)
   2051 {
   2052 	pd_entry_t *pde;
   2053 	paddr_t pa;
   2054 	struct vm_page *m;
   2055 
   2056 	if (pmap == pmap_kernel())
   2057 		return;
   2058 
   2059 	pde = pmap_pde(pmap, va & PD_FRAME);
   2060 	pa = pmap_pte_pa(pde);
   2061 	m = PHYS_TO_VM_PAGE(pa);
   2062 	m->wire_count--;
   2063 #ifdef MYCROFT_HACK
   2064 	printf("delref pmap=%p va=%08lx pde=%p pa=%08lx m=%p wire=%d\n",
   2065 	    pmap, va, pde, pa, m, m->wire_count);
   2066 #endif
   2067 	if (m->wire_count == 0) {
   2068 #ifdef MYCROFT_HACK
   2069 		printf("delref pmap=%p va=%08lx pde=%p pa=%08lx m=%p\n",
   2070 		    pmap, va, pde, pa, m);
   2071 #endif
   2072 		pmap_unmap_in_l1(pmap, va & PD_FRAME);
   2073 		uvm_pagefree(m);
   2074 		--pmap->pm_stats.resident_count;
   2075 	}
   2076 }
   2077 #else
   2078 #define	pmap_pte_addref(pmap, va)
   2079 #define	pmap_pte_delref(pmap, va)
   2080 #endif
   2081 
   2082 /*
   2083  * Since we have a virtually indexed cache, we may need to inhibit caching if
   2084  * there is more than one mapping and at least one of them is writable.
   2085  * Since we purge the cache on every context switch, we only need to check for
   2086  * other mappings within the same pmap, or kernel_pmap.
   2087  * This function is also called when a page is unmapped, to possibly reenable
   2088  * caching on any remaining mappings.
   2089  *
   2090  * The code implements the following logic, where:
   2091  *
   2092  * KW = # of kernel read/write pages
   2093  * KR = # of kernel read only pages
   2094  * UW = # of user read/write pages
   2095  * UR = # of user read only pages
   2096  * OW = # of user read/write pages in another pmap, then
   2097  *
   2098  * KC = kernel mapping is cacheable
   2099  * UC = user mapping is cacheable
   2100  *
   2101  *                     KW=0,KR=0  KW=0,KR>0  KW=1,KR=0  KW>1,KR>=0
   2102  *                   +---------------------------------------------
   2103  * UW=0,UR=0,OW=0    | ---        KC=1       KC=1       KC=0
   2104  * UW=0,UR>0,OW=0    | UC=1       KC=1,UC=1  KC=0,UC=0  KC=0,UC=0
   2105  * UW=0,UR>0,OW>0    | UC=1       KC=0,UC=1  KC=0,UC=0  KC=0,UC=0
   2106  * UW=1,UR=0,OW=0    | UC=1       KC=0,UC=0  KC=0,UC=0  KC=0,UC=0
   2107  * UW>1,UR>=0,OW>=0  | UC=0       KC=0,UC=0  KC=0,UC=0  KC=0,UC=0
   2108  *
   2109  * Note that the pmap must have it's ptes mapped in, and passed with ptes.
   2110  */
   2111 __inline static void
   2112 pmap_vac_me_harder(struct pmap *pmap, struct vm_page *pg, pt_entry_t *ptes,
   2113 	boolean_t clear_cache)
   2114 {
   2115 	if (pmap == pmap_kernel())
   2116 		pmap_vac_me_kpmap(pmap, pg, ptes, clear_cache);
   2117 	else
   2118 		pmap_vac_me_user(pmap, pg, ptes, clear_cache);
   2119 }
   2120 
   2121 static void
   2122 pmap_vac_me_kpmap(struct pmap *pmap, struct vm_page *pg, pt_entry_t *ptes,
   2123 	boolean_t clear_cache)
   2124 {
   2125 	unsigned int user_entries = 0;
   2126 	unsigned int user_writable = 0;
   2127 	unsigned int user_cacheable = 0;
   2128 	unsigned int kernel_entries = 0;
   2129 	unsigned int kernel_writable = 0;
   2130 	unsigned int kernel_cacheable = 0;
   2131 	struct pv_entry *pv;
   2132 	struct pmap *last_pmap = pmap;
   2133 
   2134 #ifdef DIAGNOSTIC
   2135 	if (pmap != pmap_kernel())
   2136 		panic("pmap_vac_me_kpmap: pmap != pmap_kernel()");
   2137 #endif
   2138 
   2139 	/*
   2140 	 * Pass one, see if there are both kernel and user pmaps for
   2141 	 * this page.  Calculate whether there are user-writable or
   2142 	 * kernel-writable pages.
   2143 	 */
   2144 	for (pv = pg->mdpage.pvh_list; pv != NULL; pv = pv->pv_next) {
   2145 		if (pv->pv_pmap != pmap) {
   2146 			user_entries++;
   2147 			if (pv->pv_flags & PVF_WRITE)
   2148 				user_writable++;
   2149 			if ((pv->pv_flags & PVF_NC) == 0)
   2150 				user_cacheable++;
   2151 		} else {
   2152 			kernel_entries++;
   2153 			if (pv->pv_flags & PVF_WRITE)
   2154 				kernel_writable++;
   2155 			if ((pv->pv_flags & PVF_NC) == 0)
   2156 				kernel_cacheable++;
   2157 		}
   2158 	}
   2159 
   2160 	/*
   2161 	 * We know we have just been updating a kernel entry, so if
   2162 	 * all user pages are already cacheable, then there is nothing
   2163 	 * further to do.
   2164 	 */
   2165 	if (kernel_entries == 0 &&
   2166 	    user_cacheable == user_entries)
   2167 		return;
   2168 
   2169 	if (user_entries) {
   2170 		/*
   2171 		 * Scan over the list again, for each entry, if it
   2172 		 * might not be set correctly, call pmap_vac_me_user
   2173 		 * to recalculate the settings.
   2174 		 */
   2175 		for (pv = pg->mdpage.pvh_list; pv; pv = pv->pv_next) {
   2176 			/*
   2177 			 * We know kernel mappings will get set
   2178 			 * correctly in other calls.  We also know
   2179 			 * that if the pmap is the same as last_pmap
   2180 			 * then we've just handled this entry.
   2181 			 */
   2182 			if (pv->pv_pmap == pmap || pv->pv_pmap == last_pmap)
   2183 				continue;
   2184 			/*
   2185 			 * If there are kernel entries and this page
   2186 			 * is writable but non-cacheable, then we can
   2187 			 * skip this entry also.
   2188 			 */
   2189 			if (kernel_entries > 0 &&
   2190 			    (pv->pv_flags & (PVF_NC | PVF_WRITE)) ==
   2191 			    (PVF_NC | PVF_WRITE))
   2192 				continue;
   2193 			/*
   2194 			 * Similarly if there are no kernel-writable
   2195 			 * entries and the page is already
   2196 			 * read-only/cacheable.
   2197 			 */
   2198 			if (kernel_writable == 0 &&
   2199 			    (pv->pv_flags & (PVF_NC | PVF_WRITE)) == 0)
   2200 				continue;
   2201 			/*
   2202 			 * For some of the remaining cases, we know
   2203 			 * that we must recalculate, but for others we
   2204 			 * can't tell if they are correct or not, so
   2205 			 * we recalculate anyway.
   2206 			 */
   2207 			pmap_unmap_ptes(last_pmap);
   2208 			last_pmap = pv->pv_pmap;
   2209 			ptes = pmap_map_ptes(last_pmap);
   2210 			pmap_vac_me_user(last_pmap, pg, ptes,
   2211 			    pmap_is_curpmap(last_pmap));
   2212 		}
   2213 		/* Restore the pte mapping that was passed to us.  */
   2214 		if (last_pmap != pmap) {
   2215 			pmap_unmap_ptes(last_pmap);
   2216 			ptes = pmap_map_ptes(pmap);
   2217 		}
   2218 		if (kernel_entries == 0)
   2219 			return;
   2220 	}
   2221 
   2222 	pmap_vac_me_user(pmap, pg, ptes, clear_cache);
   2223 	return;
   2224 }
   2225 
   2226 static void
   2227 pmap_vac_me_user(struct pmap *pmap, struct vm_page *pg, pt_entry_t *ptes,
   2228 	boolean_t clear_cache)
   2229 {
   2230 	struct pmap *kpmap = pmap_kernel();
   2231 	struct pv_entry *pv, *npv;
   2232 	unsigned int entries = 0;
   2233 	unsigned int writable = 0;
   2234 	unsigned int cacheable_entries = 0;
   2235 	unsigned int kern_cacheable = 0;
   2236 	unsigned int other_writable = 0;
   2237 
   2238 	pv = pg->mdpage.pvh_list;
   2239 	KASSERT(ptes != NULL);
   2240 
   2241 	/*
   2242 	 * Count mappings and writable mappings in this pmap.
   2243 	 * Include kernel mappings as part of our own.
   2244 	 * Keep a pointer to the first one.
   2245 	 */
   2246 	for (npv = pv; npv; npv = npv->pv_next) {
   2247 		/* Count mappings in the same pmap */
   2248 		if (pmap == npv->pv_pmap ||
   2249 		    kpmap == npv->pv_pmap) {
   2250 			if (entries++ == 0)
   2251 				pv = npv;
   2252 			/* Cacheable mappings */
   2253 			if ((npv->pv_flags & PVF_NC) == 0) {
   2254 				cacheable_entries++;
   2255 				if (kpmap == npv->pv_pmap)
   2256 					kern_cacheable++;
   2257 			}
   2258 			/* Writable mappings */
   2259 			if (npv->pv_flags & PVF_WRITE)
   2260 				++writable;
   2261 		} else if (npv->pv_flags & PVF_WRITE)
   2262 			other_writable = 1;
   2263 	}
   2264 
   2265 	PDEBUG(3,printf("pmap_vac_me_harder: pmap %p Entries %d, "
   2266 		"writable %d cacheable %d %s\n", pmap, entries, writable,
   2267 	    	cacheable_entries, clear_cache ? "clean" : "no clean"));
   2268 
   2269 	/*
   2270 	 * Enable or disable caching as necessary.
   2271 	 * Note: the first entry might be part of the kernel pmap,
   2272 	 * so we can't assume this is indicative of the state of the
   2273 	 * other (maybe non-kpmap) entries.
   2274 	 */
   2275 	if ((entries > 1 && writable) ||
   2276 	    (entries > 0 && pmap == kpmap && other_writable)) {
   2277 		if (cacheable_entries == 0)
   2278 		    return;
   2279 		for (npv = pv; npv; npv = npv->pv_next) {
   2280 			if ((pmap == npv->pv_pmap
   2281 			    || kpmap == npv->pv_pmap) &&
   2282 			    (npv->pv_flags & PVF_NC) == 0) {
   2283 				ptes[arm_btop(npv->pv_va)] &= ~L2_S_CACHE_MASK;
   2284 				PTE_SYNC_CURRENT(pmap,
   2285 				    &ptes[arm_btop(npv->pv_va)]);
   2286  				npv->pv_flags |= PVF_NC;
   2287 				/*
   2288 				 * If this page needs flushing from the
   2289 				 * cache, and we aren't going to do it
   2290 				 * below, do it now.
   2291 				 */
   2292 				if ((cacheable_entries < 4 &&
   2293 				    (clear_cache || npv->pv_pmap == kpmap)) ||
   2294 				    (npv->pv_pmap == kpmap &&
   2295 				    !clear_cache && kern_cacheable < 4)) {
   2296 					cpu_idcache_wbinv_range(npv->pv_va,
   2297 					    NBPG);
   2298 					cpu_tlb_flushID_SE(npv->pv_va);
   2299 				}
   2300 			}
   2301 		}
   2302 		if ((clear_cache && cacheable_entries >= 4) ||
   2303 		    kern_cacheable >= 4) {
   2304 			cpu_idcache_wbinv_all();
   2305 			cpu_tlb_flushID();
   2306 		}
   2307 		cpu_cpwait();
   2308 	} else if (entries > cacheable_entries) {
   2309 		/*
   2310 		 * Turn cacheing back on for some pages.  If it is a kernel
   2311 		 * page, only do so if there are no other writable pages.
   2312 		 */
   2313 		for (npv = pv; npv; npv = npv->pv_next) {
   2314 			if ((pmap == npv->pv_pmap ||
   2315 			    (kpmap == npv->pv_pmap && other_writable == 0)) &&
   2316 			    (npv->pv_flags & PVF_NC)) {
   2317 				ptes[arm_btop(npv->pv_va)] |=
   2318 				    pte_l2_s_cache_mode;
   2319 				PTE_SYNC_CURRENT(pmap,
   2320 				    &ptes[arm_btop(npv->pv_va)]);
   2321 				npv->pv_flags &= ~PVF_NC;
   2322 			}
   2323 		}
   2324 	}
   2325 }
   2326 
   2327 /*
   2328  * pmap_remove()
   2329  *
   2330  * pmap_remove is responsible for nuking a number of mappings for a range
   2331  * of virtual address space in the current pmap. To do this efficiently
   2332  * is interesting, because in a number of cases a wide virtual address
   2333  * range may be supplied that contains few actual mappings. So, the
   2334  * optimisations are:
   2335  *  1. Try and skip over hunks of address space for which an L1 entry
   2336  *     does not exist.
   2337  *  2. Build up a list of pages we've hit, up to a maximum, so we can
   2338  *     maybe do just a partial cache clean. This path of execution is
   2339  *     complicated by the fact that the cache must be flushed _before_
   2340  *     the PTE is nuked, being a VAC :-)
   2341  *  3. Maybe later fast-case a single page, but I don't think this is
   2342  *     going to make _that_ much difference overall.
   2343  */
   2344 
   2345 #define PMAP_REMOVE_CLEAN_LIST_SIZE	3
   2346 
   2347 void
   2348 pmap_remove(struct pmap *pmap, vaddr_t sva, vaddr_t eva)
   2349 {
   2350 	unsigned int cleanlist_idx = 0;
   2351 	struct pagelist {
   2352 		vaddr_t va;
   2353 		pt_entry_t *pte;
   2354 	} cleanlist[PMAP_REMOVE_CLEAN_LIST_SIZE];
   2355 	pt_entry_t *pte = 0, *ptes;
   2356 	paddr_t pa;
   2357 	int pmap_active;
   2358 	struct vm_page *pg;
   2359 	struct pv_entry *pv_tofree = NULL;
   2360 
   2361 	/* Exit quick if there is no pmap */
   2362 	if (!pmap)
   2363 		return;
   2364 
   2365 	NPDEBUG(PDB_REMOVE, printf("pmap_remove: pmap=%p sva=%08lx eva=%08lx\n",
   2366 	    pmap, sva, eva));
   2367 
   2368 	/*
   2369 	 * we lock in the pmap => vm_page direction
   2370 	 */
   2371 	PMAP_MAP_TO_HEAD_LOCK();
   2372 
   2373 	ptes = pmap_map_ptes(pmap);
   2374 	/* Get a page table pointer */
   2375 	while (sva < eva) {
   2376 		if (pmap_pde_page(pmap_pde(pmap, sva)))
   2377 			break;
   2378 		sva = (sva & L1_S_FRAME) + L1_S_SIZE;
   2379 	}
   2380 
   2381 	pte = &ptes[arm_btop(sva)];
   2382 	/* Note if the pmap is active thus require cache and tlb cleans */
   2383 	pmap_active = pmap_is_curpmap(pmap);
   2384 
   2385 	/* Now loop along */
   2386 	while (sva < eva) {
   2387 		/* Check if we can move to the next PDE (l1 chunk) */
   2388 		if ((sva & L2_ADDR_BITS) == 0) {
   2389 			if (!pmap_pde_page(pmap_pde(pmap, sva))) {
   2390 				sva += L1_S_SIZE;
   2391 				pte += arm_btop(L1_S_SIZE);
   2392 				continue;
   2393 			}
   2394 		}
   2395 
   2396 		/* We've found a valid PTE, so this page of PTEs has to go. */
   2397 		if (pmap_pte_v(pte)) {
   2398 			/* Update statistics */
   2399 			--pmap->pm_stats.resident_count;
   2400 
   2401 			/*
   2402 			 * Add this page to our cache remove list, if we can.
   2403 			 * If, however the cache remove list is totally full,
   2404 			 * then do a complete cache invalidation taking note
   2405 			 * to backtrack the PTE table beforehand, and ignore
   2406 			 * the lists in future because there's no longer any
   2407 			 * point in bothering with them (we've paid the
   2408 			 * penalty, so will carry on unhindered). Otherwise,
   2409 			 * when we fall out, we just clean the list.
   2410 			 */
   2411 			PDEBUG(10, printf("remove: inv pte at %p(%x) ", pte, *pte));
   2412 			pa = pmap_pte_pa(pte);
   2413 
   2414 			if (cleanlist_idx < PMAP_REMOVE_CLEAN_LIST_SIZE) {
   2415 				/* Add to the clean list. */
   2416 				cleanlist[cleanlist_idx].pte = pte;
   2417 				cleanlist[cleanlist_idx].va = sva;
   2418 				cleanlist_idx++;
   2419 			} else if (cleanlist_idx == PMAP_REMOVE_CLEAN_LIST_SIZE) {
   2420 				unsigned int cnt;
   2421 
   2422 				/* Nuke everything if needed. */
   2423 				if (pmap_active) {
   2424 					cpu_idcache_wbinv_all();
   2425 					cpu_tlb_flushID();
   2426 				}
   2427 
   2428 				/*
   2429 				 * Roll back the previous PTE list,
   2430 				 * and zero out the current PTE.
   2431 				 */
   2432 				for (cnt = 0;
   2433 				     cnt < PMAP_REMOVE_CLEAN_LIST_SIZE;
   2434 				     cnt++) {
   2435 					*cleanlist[cnt].pte = 0;
   2436 					if (pmap_active)
   2437 						PTE_SYNC(cleanlist[cnt].pte);
   2438 					else
   2439 						PTE_FLUSH(cleanlist[cnt].pte);
   2440 					pmap_pte_delref(pmap,
   2441 					    cleanlist[cnt].va);
   2442 				}
   2443 				*pte = 0;
   2444 				if (pmap_active)
   2445 					PTE_SYNC(pte);
   2446 				else
   2447 					PTE_FLUSH(pte);
   2448 				pmap_pte_delref(pmap, sva);
   2449 				cleanlist_idx++;
   2450 			} else {
   2451 				/*
   2452 				 * We've already nuked the cache and
   2453 				 * TLB, so just carry on regardless,
   2454 				 * and we won't need to do it again
   2455 				 */
   2456 				*pte = 0;
   2457 				if (pmap_active)
   2458 					PTE_SYNC(pte);
   2459 				else
   2460 					PTE_FLUSH(pte);
   2461 				pmap_pte_delref(pmap, sva);
   2462 			}
   2463 
   2464 			/*
   2465 			 * Update flags. In a number of circumstances,
   2466 			 * we could cluster a lot of these and do a
   2467 			 * number of sequential pages in one go.
   2468 			 */
   2469 			if ((pg = PHYS_TO_VM_PAGE(pa)) != NULL) {
   2470 				struct pv_entry *pve;
   2471 				simple_lock(&pg->mdpage.pvh_slock);
   2472 				pve = pmap_remove_pv(pg, pmap, sva);
   2473 				pmap_vac_me_harder(pmap, pg, ptes, FALSE);
   2474 				simple_unlock(&pg->mdpage.pvh_slock);
   2475 				if (pve != NULL) {
   2476 					pve->pv_next = pv_tofree;
   2477 					pv_tofree = pve;
   2478 				}
   2479 			}
   2480 		} else if (pmap_active == 0)
   2481 			PTE_FLUSH(pte);
   2482 		sva += NBPG;
   2483 		pte++;
   2484 	}
   2485 
   2486 	/*
   2487 	 * Now, if we've fallen through down to here, chances are that there
   2488 	 * are less than PMAP_REMOVE_CLEAN_LIST_SIZE mappings left.
   2489 	 */
   2490 	if (cleanlist_idx <= PMAP_REMOVE_CLEAN_LIST_SIZE) {
   2491 		u_int cnt;
   2492 
   2493 		for (cnt = 0; cnt < cleanlist_idx; cnt++) {
   2494 			if (pmap_active) {
   2495 				cpu_idcache_wbinv_range(cleanlist[cnt].va,
   2496 				    NBPG);
   2497 				*cleanlist[cnt].pte = 0;
   2498 				cpu_tlb_flushID_SE(cleanlist[cnt].va);
   2499 				PTE_SYNC(cleanlist[cnt].pte);
   2500 			} else {
   2501 				*cleanlist[cnt].pte = 0;
   2502 				PTE_FLUSH(cleanlist[cnt].pte);
   2503 			}
   2504 			pmap_pte_delref(pmap, cleanlist[cnt].va);
   2505 		}
   2506 	}
   2507 
   2508 	/* Delete pv entries */
   2509 	if (pv_tofree != NULL)
   2510 		pmap_free_pvs(pmap, pv_tofree);
   2511 
   2512 	pmap_unmap_ptes(pmap);
   2513 
   2514 	PMAP_MAP_TO_HEAD_UNLOCK();
   2515 }
   2516 
   2517 /*
   2518  * Routine:	pmap_page_remove
   2519  * Function:
   2520  *		Removes this physical page from
   2521  *		all physical maps in which it resides.
   2522  *		Reflects back modify bits to the pager.
   2523  */
   2524 
   2525 static void
   2526 pmap_page_remove(struct vm_page *pg)
   2527 {
   2528 	struct pv_entry *pv, *npv;
   2529 	struct pmap *pmap;
   2530 	pt_entry_t *pte, *ptes;
   2531 
   2532 	PDEBUG(0, printf("pmap_page_remove: pa=%lx ", VM_PAGE_TO_PHYS(pg)));
   2533 
   2534 	/* set vm_page => pmap locking */
   2535 	PMAP_HEAD_TO_MAP_LOCK();
   2536 
   2537 	simple_lock(&pg->mdpage.pvh_slock);
   2538 
   2539 	pv = pg->mdpage.pvh_list;
   2540 	if (pv == NULL) {
   2541 		PDEBUG(0, printf("free page\n"));
   2542 		simple_unlock(&pg->mdpage.pvh_slock);
   2543 		PMAP_HEAD_TO_MAP_UNLOCK();
   2544 		return;
   2545 	}
   2546 	pmap_clean_page(pv, FALSE);
   2547 
   2548 	while (pv) {
   2549 		pmap = pv->pv_pmap;
   2550 		ptes = pmap_map_ptes(pmap);
   2551 		pte = &ptes[arm_btop(pv->pv_va)];
   2552 
   2553 		PDEBUG(0, printf("[%p,%08x,%08lx,%08x] ", pmap, *pte,
   2554 		    pv->pv_va, pv->pv_flags));
   2555 #ifdef DEBUG
   2556 		if (pmap_pde_page(pmap_pde(pmap, pv->pv_va)) == 0 ||
   2557 		    pmap_pte_v(pte) == 0 ||
   2558 		    pmap_pte_pa(pte) != VM_PAGE_TO_PHYS(pg))
   2559 			panic("pmap_page_remove: bad mapping");
   2560 #endif	/* DEBUG */
   2561 
   2562 		/*
   2563 		 * Update statistics
   2564 		 */
   2565 		--pmap->pm_stats.resident_count;
   2566 
   2567 		/* Wired bit */
   2568 		if (pv->pv_flags & PVF_WIRED)
   2569 			--pmap->pm_stats.wired_count;
   2570 
   2571 		/*
   2572 		 * Invalidate the PTEs.
   2573 		 * XXX: should cluster them up and invalidate as many
   2574 		 * as possible at once.
   2575 		 */
   2576 
   2577 #ifdef needednotdone
   2578 reduce wiring count on page table pages as references drop
   2579 #endif
   2580 
   2581 		*pte = 0;
   2582 		PTE_SYNC_CURRENT(pmap, pte);
   2583 		pmap_pte_delref(pmap, pv->pv_va);
   2584 
   2585 		npv = pv->pv_next;
   2586 		pmap_free_pv(pmap, pv);
   2587 		pv = npv;
   2588 		pmap_unmap_ptes(pmap);
   2589 	}
   2590 	pg->mdpage.pvh_list = NULL;
   2591 	simple_unlock(&pg->mdpage.pvh_slock);
   2592 	PMAP_HEAD_TO_MAP_UNLOCK();
   2593 
   2594 	PDEBUG(0, printf("done\n"));
   2595 	cpu_tlb_flushID();
   2596 	cpu_cpwait();
   2597 }
   2598 
   2599 
   2600 /*
   2601  * Set the physical protection on the specified range of this map as requested.
   2602  */
   2603 
   2604 void
   2605 pmap_protect(struct pmap *pmap, vaddr_t sva, vaddr_t eva, vm_prot_t prot)
   2606 {
   2607 	pt_entry_t *pte = NULL, *ptes;
   2608 	struct vm_page *pg;
   2609 	boolean_t flush = FALSE;
   2610 
   2611 	PDEBUG(0, printf("pmap_protect: pmap=%p %08lx->%08lx %x\n",
   2612 	    pmap, sva, eva, prot));
   2613 
   2614 	if (~prot & VM_PROT_READ) {
   2615 		/*
   2616 		 * Just remove the mappings.  pmap_update() is not required
   2617 		 * here since the caller should do it.
   2618 		 */
   2619 		pmap_remove(pmap, sva, eva);
   2620 		return;
   2621 	}
   2622 	if (prot & VM_PROT_WRITE) {
   2623 		/*
   2624 		 * If this is a read->write transition, just ignore it and let
   2625 		 * uvm_fault() take care of it later.
   2626 		 */
   2627 		return;
   2628 	}
   2629 
   2630 	/* Need to lock map->head */
   2631 	PMAP_MAP_TO_HEAD_LOCK();
   2632 
   2633 	ptes = pmap_map_ptes(pmap);
   2634 
   2635 	/*
   2636 	 * OK, at this point, we know we're doing write-protect operation.
   2637 	 * If the pmap is active, write-back the range.
   2638 	 */
   2639 	if (pmap_is_curpmap(pmap))
   2640 		cpu_dcache_wb_range(sva, eva - sva);
   2641 
   2642 	/*
   2643 	 * We need to acquire a pointer to a page table page before entering
   2644 	 * the following loop.
   2645 	 */
   2646 	while (sva < eva) {
   2647 		if (pmap_pde_page(pmap_pde(pmap, sva)))
   2648 			break;
   2649 		sva = (sva & L1_S_FRAME) + L1_S_SIZE;
   2650 	}
   2651 
   2652 	pte = &ptes[arm_btop(sva)];
   2653 
   2654 	while (sva < eva) {
   2655 		/* only check once in a while */
   2656 		if ((sva & L2_ADDR_BITS) == 0) {
   2657 			if (!pmap_pde_page(pmap_pde(pmap, sva))) {
   2658 				/* We can race ahead here, to the next pde. */
   2659 				sva += L1_S_SIZE;
   2660 				pte += arm_btop(L1_S_SIZE);
   2661 				continue;
   2662 			}
   2663 		}
   2664 
   2665 		if (!pmap_pte_v(pte)) {
   2666 			PTE_FLUSH_ALT(pmap, pte);
   2667 			goto next;
   2668 		}
   2669 
   2670 		flush = TRUE;
   2671 
   2672 		pg = PHYS_TO_VM_PAGE(pmap_pte_pa(pte));
   2673 
   2674 		*pte &= ~L2_S_PROT_W;		/* clear write bit */
   2675 		PTE_SYNC_CURRENT(pmap, pte);	/* XXXJRT optimize */
   2676 
   2677 		/* Clear write flag */
   2678 		if (pg != NULL) {
   2679 			simple_lock(&pg->mdpage.pvh_slock);
   2680 			(void) pmap_modify_pv(pmap, sva, pg, PVF_WRITE, 0);
   2681 			pmap_vac_me_harder(pmap, pg, ptes, FALSE);
   2682 			simple_unlock(&pg->mdpage.pvh_slock);
   2683 		}
   2684 
   2685  next:
   2686 		sva += NBPG;
   2687 		pte++;
   2688 	}
   2689 	pmap_unmap_ptes(pmap);
   2690 	PMAP_MAP_TO_HEAD_UNLOCK();
   2691 	if (flush)
   2692 		cpu_tlb_flushID();
   2693 }
   2694 
   2695 /*
   2696  * void pmap_enter(struct pmap *pmap, vaddr_t va, paddr_t pa, vm_prot_t prot,
   2697  * int flags)
   2698  *
   2699  *      Insert the given physical page (p) at
   2700  *      the specified virtual address (v) in the
   2701  *      target physical map with the protection requested.
   2702  *
   2703  *      If specified, the page will be wired down, meaning
   2704  *      that the related pte can not be reclaimed.
   2705  *
   2706  *      NB:  This is the only routine which MAY NOT lazy-evaluate
   2707  *      or lose information.  That is, this routine must actually
   2708  *      insert this page into the given map NOW.
   2709  */
   2710 
   2711 int
   2712 pmap_enter(struct pmap *pmap, vaddr_t va, paddr_t pa, vm_prot_t prot,
   2713     int flags)
   2714 {
   2715 	pt_entry_t *ptes, opte, npte;
   2716 	paddr_t opa;
   2717 	boolean_t wired = (flags & PMAP_WIRED) != 0;
   2718 	struct vm_page *pg;
   2719 	struct pv_entry *pve;
   2720 	int error;
   2721 	unsigned int nflags;
   2722 	struct vm_page *ptp = NULL;
   2723 
   2724 	NPDEBUG(PDB_ENTER, printf("pmap_enter: V%08lx P%08lx in pmap %p prot=%08x, flags=%08x, wired = %d\n",
   2725 	    va, pa, pmap, prot, flags, wired));
   2726 
   2727 	KDASSERT((flags & PMAP_WIRED) == 0 || (flags & VM_PROT_ALL) != 0);
   2728 
   2729 #ifdef DIAGNOSTIC
   2730 	/* Valid address ? */
   2731 	if (va >= (pmap_curmaxkvaddr))
   2732 		panic("pmap_enter: too big");
   2733 	if (pmap != pmap_kernel() && va != 0) {
   2734 		if (va < VM_MIN_ADDRESS || va >= VM_MAXUSER_ADDRESS)
   2735 			panic("pmap_enter: kernel page in user map");
   2736 	} else {
   2737 		if (va >= VM_MIN_ADDRESS && va < VM_MAXUSER_ADDRESS)
   2738 			panic("pmap_enter: user page in kernel map");
   2739 		if (va >= VM_MAXUSER_ADDRESS && va < VM_MAX_ADDRESS)
   2740 			panic("pmap_enter: entering PT page");
   2741 	}
   2742 #endif
   2743 
   2744 	KDASSERT(((va | pa) & PGOFSET) == 0);
   2745 
   2746 	/*
   2747 	 * Get a pointer to the page.  Later on in this function, we
   2748 	 * test for a managed page by checking pg != NULL.
   2749 	 */
   2750 	pg = pmap_initialized ? PHYS_TO_VM_PAGE(pa) : NULL;
   2751 
   2752 	/* get lock */
   2753 	PMAP_MAP_TO_HEAD_LOCK();
   2754 
   2755 	/*
   2756 	 * map the ptes.  If there's not already an L2 table for this
   2757 	 * address, allocate one.
   2758 	 */
   2759 	ptes = pmap_map_ptes(pmap);		/* locks pmap */
   2760 	/* kernel should be pre-grown */
   2761 	if (pmap != pmap_kernel())
   2762 	{
   2763 		/* if failure is allowed then don't try too hard */
   2764 		ptp = pmap_get_ptp(pmap, va & PD_FRAME);
   2765 		if (ptp == NULL) {
   2766 			if (flags & PMAP_CANFAIL) {
   2767 				error = ENOMEM;
   2768 				goto out;
   2769 			}
   2770 			panic("pmap_enter: get ptp failed");
   2771 		}
   2772 	}
   2773 	opte = ptes[arm_btop(va)];
   2774 
   2775 	nflags = 0;
   2776 	if (prot & VM_PROT_WRITE)
   2777 		nflags |= PVF_WRITE;
   2778 	if (wired)
   2779 		nflags |= PVF_WIRED;
   2780 
   2781 	/* Is the pte valid ? If so then this page is already mapped */
   2782 	if (l2pte_valid(opte)) {
   2783 		/* Get the physical address of the current page mapped */
   2784 		opa = l2pte_pa(opte);
   2785 
   2786 		/* Are we mapping the same page ? */
   2787 		if (opa == pa) {
   2788 			/* Check to see if we're doing rw->ro. */
   2789 			if ((opte & L2_S_PROT_W) != 0 &&
   2790 			    (prot & VM_PROT_WRITE) == 0) {
   2791 				/* Yup, flush the cache if current pmap. */
   2792 				if (pmap_is_curpmap(pmap))
   2793 					cpu_dcache_wb_range(va, NBPG);
   2794 			}
   2795 
   2796 			/* Has the wiring changed ? */
   2797 			if (pg != NULL) {
   2798 				simple_lock(&pg->mdpage.pvh_slock);
   2799 				(void) pmap_modify_pv(pmap, va, pg,
   2800 				    PVF_WRITE | PVF_WIRED, nflags);
   2801 				simple_unlock(&pg->mdpage.pvh_slock);
   2802  			}
   2803 		} else {
   2804 			struct vm_page *opg;
   2805 
   2806 			/* We are replacing the page with a new one. */
   2807 			cpu_idcache_wbinv_range(va, NBPG);
   2808 
   2809 			/*
   2810 			 * If it is part of our managed memory then we
   2811 			 * must remove it from the PV list
   2812 			 */
   2813 			if ((opg = PHYS_TO_VM_PAGE(opa)) != NULL) {
   2814 				simple_lock(&opg->mdpage.pvh_slock);
   2815 				pve = pmap_remove_pv(opg, pmap, va);
   2816 				simple_unlock(&opg->mdpage.pvh_slock);
   2817 			} else {
   2818 				pve = NULL;
   2819 			}
   2820 
   2821 			goto enter;
   2822 		}
   2823 	} else {
   2824 		opa = 0;
   2825 		pve = NULL;
   2826 
   2827 		/* bump ptp ref */
   2828 		if (ptp != NULL)
   2829 			ptp->wire_count++;
   2830 
   2831 		/* pte is not valid so we must be hooking in a new page */
   2832 		++pmap->pm_stats.resident_count;
   2833 
   2834 	enter:
   2835 		/*
   2836 		 * Enter on the PV list if part of our managed memory
   2837 		 */
   2838 		if (pg != NULL) {
   2839 			if (pve == NULL) {
   2840 				pve = pmap_alloc_pv(pmap, ALLOCPV_NEED);
   2841 				if (pve == NULL) {
   2842 					if (flags & PMAP_CANFAIL) {
   2843 						PTE_FLUSH_ALT(pmap,
   2844 						    ptes[arm_btop(va)]);
   2845 						error = ENOMEM;
   2846 						goto out;
   2847 					}
   2848 					panic("pmap_enter: no pv entries "
   2849 					    "available");
   2850 				}
   2851 			}
   2852 			/* enter_pv locks pvh when adding */
   2853 			pmap_enter_pv(pg, pve, pmap, va, ptp, nflags);
   2854 		} else {
   2855 			if (pve != NULL)
   2856 				pmap_free_pv(pmap, pve);
   2857 		}
   2858 	}
   2859 
   2860 	/* Construct the pte, giving the correct access. */
   2861 	npte = pa;
   2862 
   2863 	/* VA 0 is magic. */
   2864 	if (pmap != pmap_kernel() && va != vector_page)
   2865 		npte |= L2_S_PROT_U;
   2866 
   2867 	if (pg != NULL) {
   2868 #ifdef DIAGNOSTIC
   2869 		if ((flags & VM_PROT_ALL) & ~prot)
   2870 			panic("pmap_enter: access_type exceeds prot");
   2871 #endif
   2872 		npte |= pte_l2_s_cache_mode;
   2873 		if (flags & VM_PROT_WRITE) {
   2874 			npte |= L2_S_PROTO | L2_S_PROT_W;
   2875 			pg->mdpage.pvh_attrs |= PVF_REF | PVF_MOD;
   2876 		} else if (flags & VM_PROT_ALL) {
   2877 			npte |= L2_S_PROTO;
   2878 			pg->mdpage.pvh_attrs |= PVF_REF;
   2879 		} else
   2880 			npte |= L2_TYPE_INV;
   2881 	} else {
   2882 		if (prot & VM_PROT_WRITE)
   2883 			npte |= L2_S_PROTO | L2_S_PROT_W;
   2884 		else if (prot & VM_PROT_ALL)
   2885 			npte |= L2_S_PROTO;
   2886 		else
   2887 			npte |= L2_TYPE_INV;
   2888 	}
   2889 
   2890 #if ARM_MMU_XSCALE == 1 && defined(XSCALE_CACHE_READ_WRITE_ALLOCATE)
   2891 #if ARM_NMMUS > 1
   2892 # error "XXX Unable to use read/write-allocate and configure non-XScale"
   2893 #endif
   2894 	/*
   2895 	 * XXX BRUTAL HACK!  This allows us to limp along with
   2896 	 * XXX the read/write-allocate cache mode.
   2897 	 */
   2898 	if (pmap == pmap_kernel())
   2899 		npte &= ~L2_XSCALE_T_TEX(TEX_XSCALE_X);
   2900 #endif
   2901 	ptes[arm_btop(va)] = npte;
   2902 	PTE_SYNC_CURRENT(pmap, &ptes[arm_btop(va)]);
   2903 
   2904 	if (pg != NULL) {
   2905 		simple_lock(&pg->mdpage.pvh_slock);
   2906  		pmap_vac_me_harder(pmap, pg, ptes, pmap_is_curpmap(pmap));
   2907 		simple_unlock(&pg->mdpage.pvh_slock);
   2908 	}
   2909 
   2910 	/* Better flush the TLB ... */
   2911 	cpu_tlb_flushID_SE(va);
   2912 	error = 0;
   2913 out:
   2914 	pmap_unmap_ptes(pmap);			/* unlocks pmap */
   2915 	PMAP_MAP_TO_HEAD_UNLOCK();
   2916 
   2917 	return error;
   2918 }
   2919 
   2920 /*
   2921  * pmap_kenter_pa: enter a kernel mapping
   2922  *
   2923  * => no need to lock anything assume va is already allocated
   2924  * => should be faster than normal pmap enter function
   2925  */
   2926 void
   2927 pmap_kenter_pa(vaddr_t va, paddr_t pa, vm_prot_t prot)
   2928 {
   2929 	pt_entry_t *pte;
   2930 
   2931 	pte = vtopte(va);
   2932 	KASSERT(!pmap_pte_v(pte));
   2933 
   2934 #ifdef PMAP_ALIAS_DEBUG
   2935     {
   2936 	struct vm_page *pg;
   2937 	int s;
   2938 
   2939 	pg = PHYS_TO_VM_PAGE(pa);
   2940 	if (pg != NULL) {
   2941 		s = splhigh();
   2942 		if (pg->mdpage.ro_mappings == 0 &&
   2943 		    pg->mdpage.rw_mappings == 0 &&
   2944 		    pg->mdpage.kro_mappings == 0 &&
   2945 		    pg->mdpage.krw_mappings == 0) {
   2946 			/* This case is okay. */
   2947 		} else if (pg->mdpage.rw_mappings == 0 &&
   2948 			   pg->mdpage.krw_mappings == 0 &&
   2949 			   (prot & VM_PROT_WRITE) == 0) {
   2950 			/* This case is okay. */
   2951 		} else {
   2952 			/* Something is awry. */
   2953 			printf("pmap_kenter_pa: ro %u, rw %u, kro %u, krw %u "
   2954 			    "prot 0x%x\n", pg->mdpage.ro_mappings,
   2955 			    pg->mdpage.rw_mappings, pg->mdpage.kro_mappings,
   2956 			    pg->mdpage.krw_mappings, prot);
   2957 			Debugger();
   2958 		}
   2959 		if (prot & VM_PROT_WRITE)
   2960 			pg->mdpage.krw_mappings++;
   2961 		else
   2962 			pg->mdpage.kro_mappings++;
   2963 		splx(s);
   2964 	}
   2965     }
   2966 #endif /* PMAP_ALIAS_DEBUG */
   2967 
   2968 	*pte = L2_S_PROTO | pa |
   2969 	    L2_S_PROT(PTE_KERNEL, prot) | pte_l2_s_cache_mode;
   2970 	PTE_SYNC(pte);
   2971 }
   2972 
   2973 void
   2974 pmap_kremove(vaddr_t va, vsize_t len)
   2975 {
   2976 	pt_entry_t *pte;
   2977 	vaddr_t ova = va;
   2978 	vaddr_t olen = len;
   2979 
   2980 	for (len >>= PAGE_SHIFT; len > 0; len--, va += PAGE_SIZE) {
   2981 
   2982 		/*
   2983 		 * We assume that we will only be called with small
   2984 		 * regions of memory.
   2985 		 */
   2986 
   2987 		KASSERT(pmap_pde_page(pmap_pde(pmap_kernel(), va)));
   2988 		pte = vtopte(va);
   2989 #ifdef PMAP_ALIAS_DEBUG
   2990     {
   2991 		struct vm_page *pg;
   2992 		int s;
   2993 
   2994 		if ((*pte & L2_TYPE_MASK) != L2_TYPE_INV &&
   2995 		    (pg = PHYS_TO_VM_PAGE(*pte & L2_S_FRAME)) != NULL) {
   2996 			s = splhigh();
   2997 			if (*pte & L2_S_PROT_W) {
   2998 				KASSERT(pg->mdpage.krw_mappings != 0);
   2999 				pg->mdpage.krw_mappings--;
   3000 			} else {
   3001 				KASSERT(pg->mdpage.kro_mappings != 0);
   3002 				pg->mdpage.kro_mappings--;
   3003 			}
   3004 			splx(s);
   3005 		}
   3006     }
   3007 #endif /* PMAP_ALIAS_DEBUG */
   3008 		cpu_idcache_wbinv_range(va, PAGE_SIZE);
   3009 		*pte = 0;
   3010 		cpu_tlb_flushID_SE(va);
   3011 	}
   3012 	PTE_SYNC_RANGE(vtopte(ova), olen >> PAGE_SHIFT);
   3013 }
   3014 
   3015 /*
   3016  * pmap_page_protect:
   3017  *
   3018  * Lower the permission for all mappings to a given page.
   3019  */
   3020 
   3021 void
   3022 pmap_page_protect(struct vm_page *pg, vm_prot_t prot)
   3023 {
   3024 
   3025 	PDEBUG(0, printf("pmap_page_protect(pa=%lx, prot=%d)\n",
   3026 	    VM_PAGE_TO_PHYS(pg), prot));
   3027 
   3028 	switch(prot) {
   3029 	case VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE:
   3030 	case VM_PROT_READ|VM_PROT_WRITE:
   3031 		return;
   3032 
   3033 	case VM_PROT_READ:
   3034 	case VM_PROT_READ|VM_PROT_EXECUTE:
   3035 		pmap_clearbit(pg, PVF_WRITE);
   3036 		break;
   3037 
   3038 	default:
   3039 		pmap_page_remove(pg);
   3040 		break;
   3041 	}
   3042 }
   3043 
   3044 
   3045 /*
   3046  * Routine:	pmap_unwire
   3047  * Function:	Clear the wired attribute for a map/virtual-address
   3048  *		pair.
   3049  * In/out conditions:
   3050  *		The mapping must already exist in the pmap.
   3051  */
   3052 
   3053 void
   3054 pmap_unwire(struct pmap *pmap, vaddr_t va)
   3055 {
   3056 	pt_entry_t *ptes;
   3057 	struct vm_page *pg;
   3058 	paddr_t pa;
   3059 
   3060 	PMAP_MAP_TO_HEAD_LOCK();
   3061 	ptes = pmap_map_ptes(pmap);		/* locks pmap */
   3062 
   3063 	if (pmap_pde_v(pmap_pde(pmap, va))) {
   3064 #ifdef DIAGNOSTIC
   3065 		if (l2pte_valid(ptes[arm_btop(va)]) == 0)
   3066 			panic("pmap_unwire: invalid L2 PTE");
   3067 #endif
   3068 		/* Extract the physical address of the page */
   3069 		pa = l2pte_pa(ptes[arm_btop(va)]);
   3070 		PTE_FLUSH_ALT(pmap, &ptes[arm_btop(va)]);
   3071 
   3072 		if ((pg = PHYS_TO_VM_PAGE(pa)) == NULL)
   3073 			goto out;
   3074 
   3075 		/* Update the wired bit in the pv entry for this page. */
   3076 		simple_lock(&pg->mdpage.pvh_slock);
   3077 		(void) pmap_modify_pv(pmap, va, pg, PVF_WIRED, 0);
   3078 		simple_unlock(&pg->mdpage.pvh_slock);
   3079 	}
   3080 #ifdef DIAGNOSTIC
   3081 	else {
   3082 		panic("pmap_unwire: invalid L1 PTE");
   3083 	}
   3084 #endif
   3085  out:
   3086 	pmap_unmap_ptes(pmap);			/* unlocks pmap */
   3087 	PMAP_MAP_TO_HEAD_UNLOCK();
   3088 }
   3089 
   3090 /*
   3091  * Routine:  pmap_extract
   3092  * Function:
   3093  *           Extract the physical page address associated
   3094  *           with the given map/virtual_address pair.
   3095  */
   3096 boolean_t
   3097 pmap_extract(struct pmap *pmap, vaddr_t va, paddr_t *pap)
   3098 {
   3099 	pd_entry_t *pde;
   3100 	pt_entry_t *pte, *ptes;
   3101 	paddr_t pa;
   3102 
   3103 	PDEBUG(5, printf("pmap_extract: pmap=%p, va=0x%08lx -> ", pmap, va));
   3104 
   3105 	ptes = pmap_map_ptes(pmap);		/* locks pmap */
   3106 
   3107 	pde = pmap_pde(pmap, va);
   3108 	pte = &ptes[arm_btop(va)];
   3109 
   3110 	if (pmap_pde_section(pde)) {
   3111 		pa = (*pde & L1_S_FRAME) | (va & L1_S_OFFSET);
   3112 		PDEBUG(5, printf("section pa=0x%08lx\n", pa));
   3113 		goto out;
   3114 	} else if (pmap_pde_page(pde) == 0 || pmap_pte_v(pte) == 0) {
   3115 		PDEBUG(5, printf("no mapping\n"));
   3116 		goto failed;
   3117 	}
   3118 
   3119 	if ((*pte & L2_TYPE_MASK) == L2_TYPE_L) {
   3120 		pa = (*pte & L2_L_FRAME) | (va & L2_L_OFFSET);
   3121 		PDEBUG(5, printf("large page pa=0x%08lx\n", pa));
   3122 		goto out;
   3123 	}
   3124 
   3125 	pa = (*pte & L2_S_FRAME) | (va & L2_S_OFFSET);
   3126 	PDEBUG(5, printf("small page pa=0x%08lx\n", pa));
   3127 
   3128  out:
   3129 	if (pap != NULL)
   3130 		*pap = pa;
   3131 
   3132 	PTE_FLUSH_ALT(pmap, &ptes[arm_btop(va)]);
   3133 	pmap_unmap_ptes(pmap);			/* unlocks pmap */
   3134 	return (TRUE);
   3135 
   3136  failed:
   3137 	PTE_FLUSH_ALT(pmap, &ptes[arm_btop(va)]);
   3138 	pmap_unmap_ptes(pmap);			/* unlocks pmap */
   3139 	return (FALSE);
   3140 }
   3141 
   3142 
   3143 /*
   3144  * pmap_copy:
   3145  *
   3146  *	Copy the range specified by src_addr/len from the source map to the
   3147  *	range dst_addr/len in the destination map.
   3148  *
   3149  *	This routine is only advisory and need not do anything.
   3150  */
   3151 /* Call deleted in <arm/arm32/pmap.h> */
   3152 
   3153 #if defined(PMAP_DEBUG)
   3154 void
   3155 pmap_dump_pvlist(phys, m)
   3156 	vaddr_t phys;
   3157 	char *m;
   3158 {
   3159 	struct vm_page *pg;
   3160 	struct pv_entry *pv;
   3161 
   3162 	if ((pg = PHYS_TO_VM_PAGE(phys)) == NULL) {
   3163 		printf("INVALID PA\n");
   3164 		return;
   3165 	}
   3166 	simple_lock(&pg->mdpage.pvh_slock);
   3167 	printf("%s %08lx:", m, phys);
   3168 	if (pg->mdpage.pvh_list == NULL) {
   3169 		simple_unlock(&pg->mdpage.pvh_slock);
   3170 		printf(" no mappings\n");
   3171 		return;
   3172 	}
   3173 
   3174 	for (pv = pg->mdpage.pvh_list; pv; pv = pv->pv_next)
   3175 		printf(" pmap %p va %08lx flags %08x", pv->pv_pmap,
   3176 		    pv->pv_va, pv->pv_flags);
   3177 
   3178 	printf("\n");
   3179 	simple_unlock(&pg->mdpage.pvh_slock);
   3180 }
   3181 
   3182 #endif	/* PMAP_DEBUG */
   3183 
   3184 static pt_entry_t *
   3185 pmap_map_ptes(struct pmap *pmap)
   3186 {
   3187 	struct proc *p;
   3188 
   3189     	/* the kernel's pmap is always accessible */
   3190 	if (pmap == pmap_kernel()) {
   3191 		return (pt_entry_t *)PTE_BASE;
   3192 	}
   3193 
   3194 	if (pmap_is_curpmap(pmap)) {
   3195 		simple_lock(&pmap->pm_obj.vmobjlock);
   3196 		return (pt_entry_t *)PTE_BASE;
   3197 	}
   3198 
   3199 	p = curproc;
   3200 	KDASSERT(p != NULL);
   3201 
   3202 	/* need to lock both curpmap and pmap: use ordered locking */
   3203 	if ((vaddr_t) pmap < (vaddr_t) p->p_vmspace->vm_map.pmap) {
   3204 		simple_lock(&pmap->pm_obj.vmobjlock);
   3205 		simple_lock(&p->p_vmspace->vm_map.pmap->pm_obj.vmobjlock);
   3206 	} else {
   3207 		simple_lock(&p->p_vmspace->vm_map.pmap->pm_obj.vmobjlock);
   3208 		simple_lock(&pmap->pm_obj.vmobjlock);
   3209 	}
   3210 
   3211 	pmap_map_in_l1(p->p_vmspace->vm_map.pmap, APTE_BASE,
   3212 	    pmap->pm_pptpt, 0);
   3213 	cpu_tlb_flushD();
   3214 	cpu_cpwait();
   3215 	return (pt_entry_t *)APTE_BASE;
   3216 }
   3217 
   3218 /*
   3219  * pmap_unmap_ptes: unlock the PTE mapping of "pmap"
   3220  */
   3221 
   3222 static void
   3223 pmap_unmap_ptes(struct pmap *pmap)
   3224 {
   3225 
   3226 	if (pmap == pmap_kernel()) {
   3227 		return;
   3228 	}
   3229 	if (pmap_is_curpmap(pmap)) {
   3230 		simple_unlock(&pmap->pm_obj.vmobjlock);
   3231 	} else {
   3232 		KDASSERT(curproc != NULL);
   3233 		simple_unlock(&pmap->pm_obj.vmobjlock);
   3234 		simple_unlock(
   3235 		    &curproc->p_vmspace->vm_map.pmap->pm_obj.vmobjlock);
   3236 	}
   3237 }
   3238 
   3239 /*
   3240  * Modify pte bits for all ptes corresponding to the given physical address.
   3241  * We use `maskbits' rather than `clearbits' because we're always passing
   3242  * constants and the latter would require an extra inversion at run-time.
   3243  */
   3244 
   3245 static void
   3246 pmap_clearbit(struct vm_page *pg, u_int maskbits)
   3247 {
   3248 	struct pv_entry *pv;
   3249 	pt_entry_t *ptes, npte, opte;
   3250 	vaddr_t va;
   3251 
   3252 	PDEBUG(1, printf("pmap_clearbit: pa=%08lx mask=%08x\n",
   3253 	    VM_PAGE_TO_PHYS(pg), maskbits));
   3254 
   3255 	PMAP_HEAD_TO_MAP_LOCK();
   3256 	simple_lock(&pg->mdpage.pvh_slock);
   3257 
   3258 	/*
   3259 	 * Clear saved attributes (modify, reference)
   3260 	 */
   3261 	pg->mdpage.pvh_attrs &= ~maskbits;
   3262 
   3263 	if (pg->mdpage.pvh_list == NULL) {
   3264 		simple_unlock(&pg->mdpage.pvh_slock);
   3265 		PMAP_HEAD_TO_MAP_UNLOCK();
   3266 		return;
   3267 	}
   3268 
   3269 	/*
   3270 	 * Loop over all current mappings setting/clearing as appropos
   3271 	 */
   3272 	for (pv = pg->mdpage.pvh_list; pv; pv = pv->pv_next) {
   3273 #ifdef PMAP_ALIAS_DEBUG
   3274     {
   3275 		int s = splhigh();
   3276 		if ((maskbits & PVF_WRITE) != 0 &&
   3277 		    (pv->pv_flags & PVF_WRITE) != 0) {
   3278 			KASSERT(pg->mdpage.rw_mappings != 0);
   3279 			pg->mdpage.rw_mappings--;
   3280 			pg->mdpage.ro_mappings++;
   3281 		}
   3282 		splx(s);
   3283     }
   3284 #endif /* PMAP_ALIAS_DEBUG */
   3285 		va = pv->pv_va;
   3286 		pv->pv_flags &= ~maskbits;
   3287 		ptes = pmap_map_ptes(pv->pv_pmap);	/* locks pmap */
   3288 		KASSERT(pmap_pde_v(pmap_pde(pv->pv_pmap, va)));
   3289 		npte = opte = ptes[arm_btop(va)];
   3290 		if (maskbits & (PVF_WRITE|PVF_MOD)) {
   3291 			if ((pv->pv_flags & PVF_NC)) {
   3292 				/*
   3293 				 * Entry is not cacheable: reenable
   3294 				 * the cache, nothing to flush
   3295 				 *
   3296 				 * Don't turn caching on again if this
   3297 				 * is a modified emulation.  This
   3298 				 * would be inconsitent with the
   3299 				 * settings created by
   3300 				 * pmap_vac_me_harder().
   3301 				 *
   3302 				 * There's no need to call
   3303 				 * pmap_vac_me_harder() here: all
   3304 				 * pages are loosing their write
   3305 				 * permission.
   3306 				 *
   3307 				 */
   3308 				if (maskbits & PVF_WRITE) {
   3309 					npte |= pte_l2_s_cache_mode;
   3310 					pv->pv_flags &= ~PVF_NC;
   3311 				}
   3312 			} else if (pmap_is_curpmap(pv->pv_pmap)) {
   3313 				/*
   3314 				 * Entry is cacheable: check if pmap is
   3315 				 * current if it is flush it,
   3316 				 * otherwise it won't be in the cache
   3317 				 */
   3318 				cpu_idcache_wbinv_range(pv->pv_va, NBPG);
   3319 			}
   3320 
   3321 			/* make the pte read only */
   3322 			npte &= ~L2_S_PROT_W;
   3323 		}
   3324 
   3325 		if (maskbits & PVF_REF) {
   3326 			if (pmap_is_curpmap(pv->pv_pmap) &&
   3327 			    (pv->pv_flags & PVF_NC) == 0) {
   3328 				/*
   3329 				 * Check npte here; we may have already
   3330 				 * done the wbinv above, and the validity
   3331 				 * of the PTE is the same for opte and
   3332 				 * npte.
   3333 				 */
   3334 				if (npte & L2_S_PROT_W) {
   3335 					cpu_idcache_wbinv_range(pv->pv_va,
   3336 					    NBPG);
   3337 				} else if ((npte & L2_TYPE_MASK)
   3338 					   != L2_TYPE_INV) {
   3339 					/* XXXJRT need idcache_inv_range */
   3340 					cpu_idcache_wbinv_range(pv->pv_va,
   3341 					    NBPG);
   3342 				}
   3343 			}
   3344 
   3345 			/* make the pte invalid */
   3346 			npte = (npte & ~L2_TYPE_MASK) | L2_TYPE_INV;
   3347 		}
   3348 
   3349 		if (npte != opte) {
   3350 			ptes[arm_btop(va)] = npte;
   3351 			PTE_SYNC_CURRENT(pv->pv_pmap, &ptes[arm_btop(va)]);
   3352 			/* Flush the TLB entry if a current pmap. */
   3353 			if (pmap_is_curpmap(pv->pv_pmap))
   3354 				cpu_tlb_flushID_SE(pv->pv_va);
   3355 		} else
   3356 			PTE_FLUSH_ALT(pv->pv_pmap, &ptes[arm_btop(va)]);
   3357 
   3358 		pmap_unmap_ptes(pv->pv_pmap);		/* unlocks pmap */
   3359 	}
   3360 	cpu_cpwait();
   3361 
   3362 	simple_unlock(&pg->mdpage.pvh_slock);
   3363 	PMAP_HEAD_TO_MAP_UNLOCK();
   3364 }
   3365 
   3366 /*
   3367  * pmap_clear_modify:
   3368  *
   3369  *	Clear the "modified" attribute for a page.
   3370  */
   3371 boolean_t
   3372 pmap_clear_modify(struct vm_page *pg)
   3373 {
   3374 	boolean_t rv;
   3375 
   3376 	if (pg->mdpage.pvh_attrs & PVF_MOD) {
   3377 		rv = TRUE;
   3378 		pmap_clearbit(pg, PVF_MOD);
   3379 	} else
   3380 		rv = FALSE;
   3381 
   3382 	PDEBUG(0, printf("pmap_clear_modify pa=%08lx -> %d\n",
   3383 	    VM_PAGE_TO_PHYS(pg), rv));
   3384 
   3385 	return (rv);
   3386 }
   3387 
   3388 /*
   3389  * pmap_clear_reference:
   3390  *
   3391  *	Clear the "referenced" attribute for a page.
   3392  */
   3393 boolean_t
   3394 pmap_clear_reference(struct vm_page *pg)
   3395 {
   3396 	boolean_t rv;
   3397 
   3398 	if (pg->mdpage.pvh_attrs & PVF_REF) {
   3399 		rv = TRUE;
   3400 		pmap_clearbit(pg, PVF_REF);
   3401 	} else
   3402 		rv = FALSE;
   3403 
   3404 	PDEBUG(0, printf("pmap_clear_reference pa=%08lx -> %d\n",
   3405 	    VM_PAGE_TO_PHYS(pg), rv));
   3406 
   3407 	return (rv);
   3408 }
   3409 
   3410 /*
   3411  * pmap_is_modified:
   3412  *
   3413  *	Test if a page has the "modified" attribute.
   3414  */
   3415 /* See <arm/arm32/pmap.h> */
   3416 
   3417 /*
   3418  * pmap_is_referenced:
   3419  *
   3420  *	Test if a page has the "referenced" attribute.
   3421  */
   3422 /* See <arm/arm32/pmap.h> */
   3423 
   3424 int
   3425 pmap_modified_emulation(struct pmap *pmap, vaddr_t va)
   3426 {
   3427 	pt_entry_t *ptes;
   3428 	struct vm_page *pg;
   3429 	paddr_t pa;
   3430 	u_int flags;
   3431 	int rv = 0;
   3432 
   3433 	PDEBUG(2, printf("pmap_modified_emulation\n"));
   3434 
   3435 	PMAP_MAP_TO_HEAD_LOCK();
   3436 	ptes = pmap_map_ptes(pmap);		/* locks pmap */
   3437 
   3438 	if (pmap_pde_v(pmap_pde(pmap, va)) == 0) {
   3439 		PDEBUG(2, printf("L1 PTE invalid\n"));
   3440 		goto out;
   3441 	}
   3442 
   3443 	PDEBUG(1, printf("pte=%08x\n", ptes[arm_btop(va)]));
   3444 
   3445 	/*
   3446 	 * Don't need to PTE_FLUSH_ALT() here; this is always done
   3447 	 * with the current pmap.
   3448 	 */
   3449 
   3450 	/* Check for a invalid pte */
   3451 	if (l2pte_valid(ptes[arm_btop(va)]) == 0)
   3452 		goto out;
   3453 
   3454 	/* This can happen if user code tries to access kernel memory. */
   3455 	if ((ptes[arm_btop(va)] & L2_S_PROT_W) != 0)
   3456 		goto out;
   3457 
   3458 	/* Extract the physical address of the page */
   3459 	pa = l2pte_pa(ptes[arm_btop(va)]);
   3460 	if ((pg = PHYS_TO_VM_PAGE(pa)) == NULL)
   3461 		goto out;
   3462 
   3463 	/* Get the current flags for this page. */
   3464 	simple_lock(&pg->mdpage.pvh_slock);
   3465 
   3466 	flags = pmap_modify_pv(pmap, va, pg, 0, 0);
   3467 	PDEBUG(2, printf("pmap_modified_emulation: flags = %08x\n", flags));
   3468 
   3469 	/*
   3470 	 * Do the flags say this page is writable ? If not then it is a
   3471 	 * genuine write fault. If yes then the write fault is our fault
   3472 	 * as we did not reflect the write access in the PTE. Now we know
   3473 	 * a write has occurred we can correct this and also set the
   3474 	 * modified bit
   3475 	 */
   3476 	if (~flags & PVF_WRITE) {
   3477 	    	simple_unlock(&pg->mdpage.pvh_slock);
   3478 		goto out;
   3479 	}
   3480 
   3481 	PDEBUG(0,
   3482 	    printf("pmap_modified_emulation: Got a hit va=%08lx, pte = %08x\n",
   3483 	    va, ptes[arm_btop(va)]));
   3484 	pg->mdpage.pvh_attrs |= PVF_REF | PVF_MOD;
   3485 
   3486 	/*
   3487 	 * Re-enable write permissions for the page.  No need to call
   3488 	 * pmap_vac_me_harder(), since this is just a
   3489 	 * modified-emulation fault, and the PVF_WRITE bit isn't changing.
   3490 	 * We've already set the cacheable bits based on the assumption
   3491 	 * that we can write to this page.
   3492 	 */
   3493 	ptes[arm_btop(va)] =
   3494 	    (ptes[arm_btop(va)] & ~L2_TYPE_MASK) | L2_S_PROTO | L2_S_PROT_W;
   3495 	PTE_SYNC(&ptes[arm_btop(va)]);
   3496 	PDEBUG(0, printf("->(%08x)\n", ptes[arm_btop(va)]));
   3497 
   3498 	simple_unlock(&pg->mdpage.pvh_slock);
   3499 
   3500 	cpu_tlb_flushID_SE(va);
   3501 	cpu_cpwait();
   3502 	rv = 1;
   3503  out:
   3504 	pmap_unmap_ptes(pmap);			/* unlocks pmap */
   3505 	PMAP_MAP_TO_HEAD_UNLOCK();
   3506 	return (rv);
   3507 }
   3508 
   3509 int
   3510 pmap_handled_emulation(struct pmap *pmap, vaddr_t va)
   3511 {
   3512 	pt_entry_t *ptes;
   3513 	struct vm_page *pg;
   3514 	paddr_t pa;
   3515 	int rv = 0;
   3516 
   3517 	PDEBUG(2, printf("pmap_handled_emulation\n"));
   3518 
   3519 	PMAP_MAP_TO_HEAD_LOCK();
   3520 	ptes = pmap_map_ptes(pmap);		/* locks pmap */
   3521 
   3522 	if (pmap_pde_v(pmap_pde(pmap, va)) == 0) {
   3523 		PDEBUG(2, printf("L1 PTE invalid\n"));
   3524 		goto out;
   3525 	}
   3526 
   3527 	PDEBUG(1, printf("pte=%08x\n", ptes[arm_btop(va)]));
   3528 
   3529 	/*
   3530 	 * Don't need to PTE_FLUSH_ALT() here; this is always done
   3531 	 * with the current pmap.
   3532 	 */
   3533 
   3534 	/* Check for invalid pte */
   3535 	if (l2pte_valid(ptes[arm_btop(va)]) == 0)
   3536 		goto out;
   3537 
   3538 	/* This can happen if user code tries to access kernel memory. */
   3539 	if ((ptes[arm_btop(va)] & L2_TYPE_MASK) != L2_TYPE_INV)
   3540 		goto out;
   3541 
   3542 	/* Extract the physical address of the page */
   3543 	pa = l2pte_pa(ptes[arm_btop(va)]);
   3544 	if ((pg = PHYS_TO_VM_PAGE(pa)) == NULL)
   3545 		goto out;
   3546 
   3547 	simple_lock(&pg->mdpage.pvh_slock);
   3548 
   3549 	/*
   3550 	 * Ok we just enable the pte and mark the attibs as handled
   3551 	 * XXX Should we traverse the PV list and enable all PTEs?
   3552 	 */
   3553 	PDEBUG(0,
   3554 	    printf("pmap_handled_emulation: Got a hit va=%08lx pte = %08x\n",
   3555 	    va, ptes[arm_btop(va)]));
   3556 	pg->mdpage.pvh_attrs |= PVF_REF;
   3557 
   3558 	ptes[arm_btop(va)] = (ptes[arm_btop(va)] & ~L2_TYPE_MASK) | L2_S_PROTO;
   3559 	PTE_SYNC(&ptes[arm_btop(va)]);
   3560 	PDEBUG(0, printf("->(%08x)\n", ptes[arm_btop(va)]));
   3561 
   3562 	simple_unlock(&pg->mdpage.pvh_slock);
   3563 
   3564 	cpu_tlb_flushID_SE(va);
   3565 	cpu_cpwait();
   3566 	rv = 1;
   3567  out:
   3568 	pmap_unmap_ptes(pmap);			/* unlocks pmap */
   3569 	PMAP_MAP_TO_HEAD_UNLOCK();
   3570 	return (rv);
   3571 }
   3572 
   3573 /*
   3574  * pmap_collect: free resources held by a pmap
   3575  *
   3576  * => optional function.
   3577  * => called when a process is swapped out to free memory.
   3578  */
   3579 
   3580 void
   3581 pmap_collect(struct pmap *pmap)
   3582 {
   3583 }
   3584 
   3585 /*
   3586  * Routine:	pmap_procwr
   3587  *
   3588  * Function:
   3589  *	Synchronize caches corresponding to [addr, addr+len) in p.
   3590  *
   3591  */
   3592 void
   3593 pmap_procwr(struct proc *p, vaddr_t va, int len)
   3594 {
   3595 	/* We only need to do anything if it is the current process. */
   3596 	if (p == curproc)
   3597 		cpu_icache_sync_range(va, len);
   3598 }
   3599 /*
   3600  * PTP functions
   3601  */
   3602 
   3603 /*
   3604  * pmap_get_ptp: get a PTP (if there isn't one, allocate a new one)
   3605  *
   3606  * => pmap should NOT be pmap_kernel()
   3607  * => pmap should be locked
   3608  */
   3609 
   3610 static struct vm_page *
   3611 pmap_get_ptp(struct pmap *pmap, vaddr_t va)
   3612 {
   3613 	struct vm_page *ptp;
   3614 	pd_entry_t	*pde;
   3615 
   3616 	KASSERT((va & PD_OFFSET) == 0);		/* XXX KDASSERT */
   3617 
   3618 	pde = pmap_pde(pmap, va);
   3619 	if (pmap_pde_v(pde)) {
   3620 		/* valid... check hint (saves us a PA->PG lookup) */
   3621 		if (pmap->pm_ptphint &&
   3622 		    ((*pde) & L2_S_FRAME) ==
   3623 		    VM_PAGE_TO_PHYS(pmap->pm_ptphint))
   3624 			return (pmap->pm_ptphint);
   3625 		ptp = uvm_pagelookup(&pmap->pm_obj, va);
   3626 #ifdef DIAGNOSTIC
   3627 		if (ptp == NULL)
   3628 			panic("pmap_get_ptp: unmanaged user PTP");
   3629 #endif
   3630 		pmap->pm_ptphint = ptp;
   3631 		return(ptp);
   3632 	}
   3633 
   3634 	/* allocate a new PTP (updates ptphint) */
   3635 	return (pmap_alloc_ptp(pmap, va));
   3636 }
   3637 
   3638 /*
   3639  * pmap_alloc_ptp: allocate a PTP for a PMAP
   3640  *
   3641  * => pmap should already be locked by caller
   3642  * => we use the ptp's wire_count to count the number of active mappings
   3643  *	in the PTP (we start it at one to prevent any chance this PTP
   3644  *	will ever leak onto the active/inactive queues)
   3645  */
   3646 
   3647 /*__inline */ static struct vm_page *
   3648 pmap_alloc_ptp(struct pmap *pmap, vaddr_t va)
   3649 {
   3650 	struct vm_page *ptp;
   3651 
   3652 	KASSERT((va & PD_OFFSET) == 0);		/* XXX KDASSERT */
   3653 
   3654 	ptp = uvm_pagealloc(&pmap->pm_obj, va, NULL,
   3655 		UVM_PGA_USERESERVE|UVM_PGA_ZERO);
   3656 	if (ptp == NULL)
   3657 		return (NULL);
   3658 
   3659 	/* got one! */
   3660 	ptp->flags &= ~PG_BUSY;	/* never busy */
   3661 	ptp->wire_count = 1;	/* no mappings yet */
   3662 	pmap_map_in_l1(pmap, va, VM_PAGE_TO_PHYS(ptp),
   3663 	    PMAP_PTP_SELFREF | PMAP_PTP_CACHEABLE);
   3664 	pmap->pm_stats.resident_count++;	/* count PTP as resident */
   3665 	pmap->pm_ptphint = ptp;
   3666 	return (ptp);
   3667 }
   3668 
   3669 vaddr_t
   3670 pmap_growkernel(vaddr_t maxkvaddr)
   3671 {
   3672 	struct pmap *kpm = pmap_kernel(), *pm;
   3673 	int s;
   3674 	paddr_t ptaddr;
   3675 	struct vm_page *ptp;
   3676 
   3677 	if (maxkvaddr <= pmap_curmaxkvaddr)
   3678 		goto out;		/* we are OK */
   3679 	NPDEBUG(PDB_GROWKERN, printf("pmap_growkernel: growing kernel from %lx to %lx\n",
   3680 		    pmap_curmaxkvaddr, maxkvaddr));
   3681 
   3682 	/*
   3683 	 * whoops!   we need to add kernel PTPs
   3684 	 */
   3685 
   3686 	s = splhigh();	/* to be safe */
   3687 	simple_lock(&kpm->pm_obj.vmobjlock);
   3688 	/* due to the way the arm pmap works we map 4MB at a time */
   3689 	for (/*null*/ ; pmap_curmaxkvaddr < maxkvaddr;
   3690 	     pmap_curmaxkvaddr += 4 * L1_S_SIZE) {
   3691 
   3692 		if (uvm.page_init_done == FALSE) {
   3693 
   3694 			/*
   3695 			 * we're growing the kernel pmap early (from
   3696 			 * uvm_pageboot_alloc()).  this case must be
   3697 			 * handled a little differently.
   3698 			 */
   3699 
   3700 			if (uvm_page_physget(&ptaddr) == FALSE)
   3701 				panic("pmap_growkernel: out of memory");
   3702 			pmap_zero_page(ptaddr);
   3703 
   3704 			/* map this page in */
   3705 			pmap_map_in_l1(kpm, pmap_curmaxkvaddr, ptaddr,
   3706 			    PMAP_PTP_SELFREF | PMAP_PTP_CACHEABLE);
   3707 
   3708 			/* count PTP as resident */
   3709 			kpm->pm_stats.resident_count++;
   3710 			continue;
   3711 		}
   3712 
   3713 		/*
   3714 		 * THIS *MUST* BE CODED SO AS TO WORK IN THE
   3715 		 * pmap_initialized == FALSE CASE!  WE MAY BE
   3716 		 * INVOKED WHILE pmap_init() IS RUNNING!
   3717 		 */
   3718 
   3719 		if ((ptp = pmap_alloc_ptp(kpm, pmap_curmaxkvaddr)) == NULL)
   3720 			panic("pmap_growkernel: alloc ptp failed");
   3721 
   3722 		/* distribute new kernel PTP to all active pmaps */
   3723 		simple_lock(&pmaps_lock);
   3724 		LIST_FOREACH(pm, &pmaps, pm_list) {
   3725 			pmap_map_in_l1(pm, pmap_curmaxkvaddr,
   3726 			    VM_PAGE_TO_PHYS(ptp),
   3727 			    PMAP_PTP_SELFREF | PMAP_PTP_CACHEABLE);
   3728 		}
   3729 
   3730 		/* Invalidate the PTPT cache. */
   3731 		pool_cache_invalidate(&pmap_ptpt_cache);
   3732 		pmap_ptpt_cache_generation++;
   3733 
   3734 		simple_unlock(&pmaps_lock);
   3735 	}
   3736 
   3737 	/*
   3738 	 * flush out the cache, expensive but growkernel will happen so
   3739 	 * rarely
   3740 	 */
   3741 	cpu_tlb_flushD();
   3742 	cpu_cpwait();
   3743 
   3744 	simple_unlock(&kpm->pm_obj.vmobjlock);
   3745 	splx(s);
   3746 
   3747 out:
   3748 	return (pmap_curmaxkvaddr);
   3749 }
   3750 
   3751 /************************ Utility routines ****************************/
   3752 
   3753 /*
   3754  * vector_page_setprot:
   3755  *
   3756  *	Manipulate the protection of the vector page.
   3757  */
   3758 void
   3759 vector_page_setprot(int prot)
   3760 {
   3761 	pt_entry_t *pte;
   3762 
   3763 	pte = vtopte(vector_page);
   3764 
   3765 	*pte = (*pte & ~L1_S_PROT_MASK) | L2_S_PROT(PTE_KERNEL, prot);
   3766 	PTE_SYNC(pte);
   3767 	cpu_tlb_flushD_SE(vector_page);
   3768 	cpu_cpwait();
   3769 }
   3770 
   3771 /************************ Bootstrapping routines ****************************/
   3772 
   3773 /*
   3774  * This list exists for the benefit of pmap_map_chunk().  It keeps track
   3775  * of the kernel L2 tables during bootstrap, so that pmap_map_chunk() can
   3776  * find them as necessary.
   3777  *
   3778  * Note that the data on this list is not valid after initarm() returns.
   3779  */
   3780 SLIST_HEAD(, pv_addr) kernel_pt_list = SLIST_HEAD_INITIALIZER(kernel_pt_list);
   3781 
   3782 static vaddr_t
   3783 kernel_pt_lookup(paddr_t pa)
   3784 {
   3785 	pv_addr_t *pv;
   3786 
   3787 	SLIST_FOREACH(pv, &kernel_pt_list, pv_list) {
   3788 		if (pv->pv_pa == pa)
   3789 			return (pv->pv_va);
   3790 	}
   3791 	return (0);
   3792 }
   3793 
   3794 /*
   3795  * pmap_map_section:
   3796  *
   3797  *	Create a single section mapping.
   3798  */
   3799 void
   3800 pmap_map_section(vaddr_t l1pt, vaddr_t va, paddr_t pa, int prot, int cache)
   3801 {
   3802 	pd_entry_t *pde = (pd_entry_t *) l1pt;
   3803 	pd_entry_t fl = (cache == PTE_CACHE) ? pte_l1_s_cache_mode : 0;
   3804 
   3805 	KASSERT(((va | pa) & L1_S_OFFSET) == 0);
   3806 
   3807 	pde[va >> L1_S_SHIFT] = L1_S_PROTO | pa |
   3808 	    L1_S_PROT(PTE_KERNEL, prot) | fl;
   3809 }
   3810 
   3811 /*
   3812  * pmap_map_entry:
   3813  *
   3814  *	Create a single page mapping.
   3815  */
   3816 void
   3817 pmap_map_entry(vaddr_t l1pt, vaddr_t va, paddr_t pa, int prot, int cache)
   3818 {
   3819 	pd_entry_t *pde = (pd_entry_t *) l1pt;
   3820 	pt_entry_t fl = (cache == PTE_CACHE) ? pte_l2_s_cache_mode : 0;
   3821 	pt_entry_t *pte;
   3822 
   3823 	KASSERT(((va | pa) & PGOFSET) == 0);
   3824 
   3825 	if ((pde[va >> L1_S_SHIFT] & L1_TYPE_MASK) != L1_TYPE_C)
   3826 		panic("pmap_map_entry: no L2 table for VA 0x%08lx", va);
   3827 
   3828 	pte = (pt_entry_t *)
   3829 	    kernel_pt_lookup(pde[va >> L1_S_SHIFT] & L2_S_FRAME);
   3830 	if (pte == NULL)
   3831 		panic("pmap_map_entry: can't find L2 table for VA 0x%08lx", va);
   3832 
   3833 	pte[(va >> PGSHIFT) & 0x3ff] = L2_S_PROTO | pa |
   3834 	    L2_S_PROT(PTE_KERNEL, prot) | fl;
   3835 }
   3836 
   3837 /*
   3838  * pmap_link_l2pt:
   3839  *
   3840  *	Link the L2 page table specified by "pa" into the L1
   3841  *	page table at the slot for "va".
   3842  */
   3843 void
   3844 pmap_link_l2pt(vaddr_t l1pt, vaddr_t va, pv_addr_t *l2pv)
   3845 {
   3846 	pd_entry_t *pde = (pd_entry_t *) l1pt;
   3847 	u_int slot = va >> L1_S_SHIFT;
   3848 
   3849 	KASSERT((l2pv->pv_pa & PGOFSET) == 0);
   3850 
   3851 	pde[slot + 0] = L1_C_PROTO | (l2pv->pv_pa + 0x000);
   3852 	pde[slot + 1] = L1_C_PROTO | (l2pv->pv_pa + 0x400);
   3853 	pde[slot + 2] = L1_C_PROTO | (l2pv->pv_pa + 0x800);
   3854 	pde[slot + 3] = L1_C_PROTO | (l2pv->pv_pa + 0xc00);
   3855 
   3856 	SLIST_INSERT_HEAD(&kernel_pt_list, l2pv, pv_list);
   3857 }
   3858 
   3859 /*
   3860  * pmap_map_chunk:
   3861  *
   3862  *	Map a chunk of memory using the most efficient mappings
   3863  *	possible (section, large page, small page) into the
   3864  *	provided L1 and L2 tables at the specified virtual address.
   3865  */
   3866 vsize_t
   3867 pmap_map_chunk(vaddr_t l1pt, vaddr_t va, paddr_t pa, vsize_t size,
   3868     int prot, int cache)
   3869 {
   3870 	pd_entry_t *pde = (pd_entry_t *) l1pt;
   3871 	pt_entry_t *pte, fl;
   3872 	vsize_t resid;
   3873 	u_int i;
   3874 
   3875 	resid = (size + (NBPG - 1)) & ~(NBPG - 1);
   3876 
   3877 	if (l1pt == 0)
   3878 		panic("pmap_map_chunk: no L1 table provided");
   3879 
   3880 #ifdef VERBOSE_INIT_ARM
   3881 	printf("pmap_map_chunk: pa=0x%lx va=0x%lx size=0x%lx resid=0x%lx "
   3882 	    "prot=0x%x cache=%d\n", pa, va, size, resid, prot, cache);
   3883 #endif
   3884 
   3885 	size = resid;
   3886 
   3887 	while (resid > 0) {
   3888 		/* See if we can use a section mapping. */
   3889 		if (((pa | va) & L1_S_OFFSET) == 0 &&
   3890 		    resid >= L1_S_SIZE) {
   3891 			fl = (cache == PTE_CACHE) ? pte_l1_s_cache_mode : 0;
   3892 #ifdef VERBOSE_INIT_ARM
   3893 			printf("S");
   3894 #endif
   3895 			pde[va >> L1_S_SHIFT] = L1_S_PROTO | pa |
   3896 			    L1_S_PROT(PTE_KERNEL, prot) | fl;
   3897 			va += L1_S_SIZE;
   3898 			pa += L1_S_SIZE;
   3899 			resid -= L1_S_SIZE;
   3900 			continue;
   3901 		}
   3902 
   3903 		/*
   3904 		 * Ok, we're going to use an L2 table.  Make sure
   3905 		 * one is actually in the corresponding L1 slot
   3906 		 * for the current VA.
   3907 		 */
   3908 		if ((pde[va >> L1_S_SHIFT] & L1_TYPE_MASK) != L1_TYPE_C)
   3909 			panic("pmap_map_chunk: no L2 table for VA 0x%08lx", va);
   3910 
   3911 		pte = (pt_entry_t *)
   3912 		    kernel_pt_lookup(pde[va >> L1_S_SHIFT] & L2_S_FRAME);
   3913 		if (pte == NULL)
   3914 			panic("pmap_map_chunk: can't find L2 table for VA"
   3915 			    "0x%08lx", va);
   3916 
   3917 		/* See if we can use a L2 large page mapping. */
   3918 		if (((pa | va) & L2_L_OFFSET) == 0 &&
   3919 		    resid >= L2_L_SIZE) {
   3920 			fl = (cache == PTE_CACHE) ? pte_l2_l_cache_mode : 0;
   3921 #ifdef VERBOSE_INIT_ARM
   3922 			printf("L");
   3923 #endif
   3924 			for (i = 0; i < 16; i++) {
   3925 				pte[((va >> PGSHIFT) & 0x3f0) + i] =
   3926 				    L2_L_PROTO | pa |
   3927 				    L2_L_PROT(PTE_KERNEL, prot) | fl;
   3928 			}
   3929 			va += L2_L_SIZE;
   3930 			pa += L2_L_SIZE;
   3931 			resid -= L2_L_SIZE;
   3932 			continue;
   3933 		}
   3934 
   3935 		/* Use a small page mapping. */
   3936 		fl = (cache == PTE_CACHE) ? pte_l2_s_cache_mode : 0;
   3937 #ifdef VERBOSE_INIT_ARM
   3938 		printf("P");
   3939 #endif
   3940 		pte[(va >> PGSHIFT) & 0x3ff] = L2_S_PROTO | pa |
   3941 		    L2_S_PROT(PTE_KERNEL, prot) | fl;
   3942 		va += NBPG;
   3943 		pa += NBPG;
   3944 		resid -= NBPG;
   3945 	}
   3946 #ifdef VERBOSE_INIT_ARM
   3947 	printf("\n");
   3948 #endif
   3949 	return (size);
   3950 }
   3951 
   3952 /********************** PTE initialization routines **************************/
   3953 
   3954 /*
   3955  * These routines are called when the CPU type is identified to set up
   3956  * the PTE prototypes, cache modes, etc.
   3957  *
   3958  * The variables are always here, just in case LKMs need to reference
   3959  * them (though, they shouldn't).
   3960  */
   3961 
   3962 pt_entry_t	pte_l1_s_cache_mode;
   3963 pt_entry_t	pte_l1_s_cache_mask;
   3964 
   3965 pt_entry_t	pte_l2_l_cache_mode;
   3966 pt_entry_t	pte_l2_l_cache_mask;
   3967 
   3968 pt_entry_t	pte_l2_s_cache_mode;
   3969 pt_entry_t	pte_l2_s_cache_mask;
   3970 
   3971 pt_entry_t	pte_l2_s_prot_u;
   3972 pt_entry_t	pte_l2_s_prot_w;
   3973 pt_entry_t	pte_l2_s_prot_mask;
   3974 
   3975 pt_entry_t	pte_l1_s_proto;
   3976 pt_entry_t	pte_l1_c_proto;
   3977 pt_entry_t	pte_l2_s_proto;
   3978 
   3979 void		(*pmap_copy_page_func)(paddr_t, paddr_t);
   3980 void		(*pmap_zero_page_func)(paddr_t);
   3981 
   3982 #if ARM_MMU_GENERIC == 1
   3983 void
   3984 pmap_pte_init_generic(void)
   3985 {
   3986 
   3987 	pte_l1_s_cache_mode = L1_S_B|L1_S_C;
   3988 	pte_l1_s_cache_mask = L1_S_CACHE_MASK_generic;
   3989 
   3990 	pte_l2_l_cache_mode = L2_B|L2_C;
   3991 	pte_l2_l_cache_mask = L2_L_CACHE_MASK_generic;
   3992 
   3993 	pte_l2_s_cache_mode = L2_B|L2_C;
   3994 	pte_l2_s_cache_mask = L2_S_CACHE_MASK_generic;
   3995 
   3996 	pte_l2_s_prot_u = L2_S_PROT_U_generic;
   3997 	pte_l2_s_prot_w = L2_S_PROT_W_generic;
   3998 	pte_l2_s_prot_mask = L2_S_PROT_MASK_generic;
   3999 
   4000 	pte_l1_s_proto = L1_S_PROTO_generic;
   4001 	pte_l1_c_proto = L1_C_PROTO_generic;
   4002 	pte_l2_s_proto = L2_S_PROTO_generic;
   4003 
   4004 	pmap_copy_page_func = pmap_copy_page_generic;
   4005 	pmap_zero_page_func = pmap_zero_page_generic;
   4006 }
   4007 
   4008 #if defined(CPU_ARM9)
   4009 void
   4010 pmap_pte_init_arm9(void)
   4011 {
   4012 
   4013 	/*
   4014 	 * ARM9 is compatible with generic, but we want to use
   4015 	 * write-through caching for now.
   4016 	 */
   4017 	pmap_pte_init_generic();
   4018 
   4019 	pte_l1_s_cache_mode = L1_S_C;
   4020 	pte_l2_l_cache_mode = L2_C;
   4021 	pte_l2_s_cache_mode = L2_C;
   4022 }
   4023 #endif /* CPU_ARM9 */
   4024 #endif /* ARM_MMU_GENERIC == 1 */
   4025 
   4026 #if ARM_MMU_XSCALE == 1
   4027 void
   4028 pmap_pte_init_xscale(void)
   4029 {
   4030 	uint32_t auxctl;
   4031 
   4032 	pte_l1_s_cache_mode = L1_S_B|L1_S_C;
   4033 	pte_l1_s_cache_mask = L1_S_CACHE_MASK_xscale;
   4034 
   4035 	pte_l2_l_cache_mode = L2_B|L2_C;
   4036 	pte_l2_l_cache_mask = L2_L_CACHE_MASK_xscale;
   4037 
   4038 	pte_l2_s_cache_mode = L2_B|L2_C;
   4039 	pte_l2_s_cache_mask = L2_S_CACHE_MASK_xscale;
   4040 
   4041 #ifdef XSCALE_CACHE_READ_WRITE_ALLOCATE
   4042 	/*
   4043 	 * The XScale core has an enhanced mode where writes that
   4044 	 * miss the cache cause a cache line to be allocated.  This
   4045 	 * is significantly faster than the traditional, write-through
   4046 	 * behavior of this case.
   4047 	 *
   4048 	 * However, there is a bug lurking in this pmap module, or in
   4049 	 * other parts of the VM system, or both, which causes corruption
   4050 	 * of NFS-backed files when this cache mode is used.  We have
   4051 	 * an ugly work-around for this problem (disable r/w-allocate
   4052 	 * for managed kernel mappings), but the bug is still evil enough
   4053 	 * to consider this cache mode "experimental".
   4054 	 */
   4055 	pte_l1_s_cache_mode |= L1_S_XSCALE_TEX(TEX_XSCALE_X);
   4056 	pte_l2_l_cache_mode |= L2_XSCALE_L_TEX(TEX_XSCALE_X);
   4057 	pte_l2_s_cache_mode |= L2_XSCALE_T_TEX(TEX_XSCALE_X);
   4058 #endif /* XSCALE_CACHE_READ_WRITE_ALLOCATE */
   4059 
   4060 #ifdef XSCALE_CACHE_WRITE_THROUGH
   4061 	/*
   4062 	 * Some versions of the XScale core have various bugs in
   4063 	 * their cache units, the work-around for which is to run
   4064 	 * the cache in write-through mode.  Unfortunately, this
   4065 	 * has a major (negative) impact on performance.  So, we
   4066 	 * go ahead and run fast-and-loose, in the hopes that we
   4067 	 * don't line up the planets in a way that will trip the
   4068 	 * bugs.
   4069 	 *
   4070 	 * However, we give you the option to be slow-but-correct.
   4071 	 */
   4072 	pte_l1_s_cache_mode = L1_S_C;
   4073 	pte_l2_l_cache_mode = L2_C;
   4074 	pte_l2_s_cache_mode = L2_C;
   4075 #endif /* XSCALE_CACHE_WRITE_THROUGH */
   4076 
   4077 	pte_l2_s_prot_u = L2_S_PROT_U_xscale;
   4078 	pte_l2_s_prot_w = L2_S_PROT_W_xscale;
   4079 	pte_l2_s_prot_mask = L2_S_PROT_MASK_xscale;
   4080 
   4081 	pte_l1_s_proto = L1_S_PROTO_xscale;
   4082 	pte_l1_c_proto = L1_C_PROTO_xscale;
   4083 	pte_l2_s_proto = L2_S_PROTO_xscale;
   4084 
   4085 	pmap_copy_page_func = pmap_copy_page_xscale;
   4086 	pmap_zero_page_func = pmap_zero_page_xscale;
   4087 
   4088 	/*
   4089 	 * Disable ECC protection of page table access, for now.
   4090 	 */
   4091 	__asm __volatile("mrc p15, 0, %0, c1, c0, 1"
   4092 		: "=r" (auxctl));
   4093 	auxctl &= ~XSCALE_AUXCTL_P;
   4094 	__asm __volatile("mcr p15, 0, %0, c1, c0, 1"
   4095 		:
   4096 		: "r" (auxctl));
   4097 }
   4098 
   4099 /*
   4100  * xscale_setup_minidata:
   4101  *
   4102  *	Set up the mini-data cache clean area.  We require the
   4103  *	caller to allocate the right amount of physically and
   4104  *	virtually contiguous space.
   4105  */
   4106 void
   4107 xscale_setup_minidata(vaddr_t l1pt, vaddr_t va, paddr_t pa)
   4108 {
   4109 	extern vaddr_t xscale_minidata_clean_addr;
   4110 	extern vsize_t xscale_minidata_clean_size; /* already initialized */
   4111 	pd_entry_t *pde = (pd_entry_t *) l1pt;
   4112 	pt_entry_t *pte;
   4113 	vsize_t size;
   4114 	uint32_t auxctl;
   4115 
   4116 	xscale_minidata_clean_addr = va;
   4117 
   4118 	/* Round it to page size. */
   4119 	size = (xscale_minidata_clean_size + L2_S_OFFSET) & L2_S_FRAME;
   4120 
   4121 	for (; size != 0;
   4122 	     va += L2_S_SIZE, pa += L2_S_SIZE, size -= L2_S_SIZE) {
   4123 		pte = (pt_entry_t *)
   4124 		    kernel_pt_lookup(pde[va >> L1_S_SHIFT] & L2_S_FRAME);
   4125 		if (pte == NULL)
   4126 			panic("xscale_setup_minidata: can't find L2 table for "
   4127 			    "VA 0x%08lx", va);
   4128 		pte[(va >> PGSHIFT) & 0x3ff] = L2_S_PROTO | pa |
   4129 		    L2_S_PROT(PTE_KERNEL, VM_PROT_READ) |
   4130 		    L2_C | L2_XSCALE_T_TEX(TEX_XSCALE_X);
   4131 	}
   4132 
   4133 	/*
   4134 	 * Configure the mini-data cache for write-back with
   4135 	 * read/write-allocate.
   4136 	 *
   4137 	 * NOTE: In order to reconfigure the mini-data cache, we must
   4138 	 * make sure it contains no valid data!  In order to do that,
   4139 	 * we must issue a global data cache invalidate command!
   4140 	 *
   4141 	 * WE ASSUME WE ARE RUNNING UN-CACHED WHEN THIS ROUTINE IS CALLED!
   4142 	 * THIS IS VERY IMPORTANT!
   4143 	 */
   4144 
   4145 	/* Invalidate data and mini-data. */
   4146 	__asm __volatile("mcr p15, 0, %0, c7, c6, 0"
   4147 		:
   4148 		: "r" (auxctl));
   4149 
   4150 
   4151 	__asm __volatile("mrc p15, 0, %0, c1, c0, 1"
   4152 		: "=r" (auxctl));
   4153 	auxctl = (auxctl & ~XSCALE_AUXCTL_MD_MASK) | XSCALE_AUXCTL_MD_WB_RWA;
   4154 	__asm __volatile("mcr p15, 0, %0, c1, c0, 1"
   4155 		:
   4156 		: "r" (auxctl));
   4157 }
   4158 #endif /* ARM_MMU_XSCALE == 1 */
   4159