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iommu.c revision 1.96
      1 /*	$NetBSD: iommu.c,v 1.96 2009/12/10 12:29:44 nakayama Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1999, 2000 Matthew R. Green
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 /*
     30  * Copyright (c) 2001, 2002 Eduardo Horvath
     31  * All rights reserved.
     32  *
     33  * Redistribution and use in source and binary forms, with or without
     34  * modification, are permitted provided that the following conditions
     35  * are met:
     36  * 1. Redistributions of source code must retain the above copyright
     37  *    notice, this list of conditions and the following disclaimer.
     38  * 2. Redistributions in binary form must reproduce the above copyright
     39  *    notice, this list of conditions and the following disclaimer in the
     40  *    documentation and/or other materials provided with the distribution.
     41  * 3. The name of the author may not be used to endorse or promote products
     42  *    derived from this software without specific prior written permission.
     43  *
     44  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     45  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     46  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     47  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     48  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     49  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     50  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     51  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     52  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     54  * SUCH DAMAGE.
     55  */
     56 
     57 /*
     58  * UltraSPARC IOMMU support; used by both the sbus and pci code.
     59  */
     60 
     61 #include <sys/cdefs.h>
     62 __KERNEL_RCSID(0, "$NetBSD: iommu.c,v 1.96 2009/12/10 12:29:44 nakayama Exp $");
     63 
     64 #include "opt_ddb.h"
     65 
     66 #include <sys/param.h>
     67 #include <sys/extent.h>
     68 #include <sys/malloc.h>
     69 #include <sys/systm.h>
     70 #include <sys/device.h>
     71 #include <sys/proc.h>
     72 
     73 #include <uvm/uvm_extern.h>
     74 
     75 #include <machine/bus.h>
     76 #include <sparc64/dev/iommureg.h>
     77 #include <sparc64/dev/iommuvar.h>
     78 
     79 #include <machine/autoconf.h>
     80 #include <machine/cpu.h>
     81 
     82 #ifdef DEBUG
     83 #define IDB_BUSDMA	0x1
     84 #define IDB_IOMMU	0x2
     85 #define IDB_INFO	0x4
     86 #define	IDB_SYNC	0x8
     87 int iommudebug = 0x0;
     88 #define DPRINTF(l, s)   do { if (iommudebug & l) printf s; } while (0)
     89 #define IOTTE_DEBUG(n)	(n)
     90 #else
     91 #define DPRINTF(l, s)
     92 #define IOTTE_DEBUG(n)	0
     93 #endif
     94 
     95 #define iommu_strbuf_flush(i, v) do {					\
     96 	if ((i)->sb_flush)						\
     97 		bus_space_write_8((i)->sb_is->is_bustag, (i)->sb_sb,	\
     98 			STRBUFREG(strbuf_pgflush), (v));		\
     99 	} while (0)
    100 
    101 static	int iommu_strbuf_flush_done(struct strbuf_ctl *);
    102 static	void _iommu_dvmamap_sync(bus_dma_tag_t, bus_dmamap_t, bus_addr_t,
    103 		bus_size_t, int);
    104 
    105 /*
    106  * initialise the UltraSPARC IOMMU (SBUS or PCI):
    107  *	- allocate and setup the iotsb.
    108  *	- enable the IOMMU
    109  *	- initialise the streaming buffers (if they exist)
    110  *	- create a private DVMA map.
    111  */
    112 void
    113 iommu_init(char *name, struct iommu_state *is, int tsbsize, uint32_t iovabase)
    114 {
    115 	psize_t size;
    116 	vaddr_t va;
    117 	paddr_t pa;
    118 	struct vm_page *pg;
    119 	struct pglist pglist;
    120 
    121 	/*
    122 	 * Setup the iommu.
    123 	 *
    124 	 * The sun4u iommu is part of the SBUS or PCI controller so we will
    125 	 * deal with it here..
    126 	 *
    127 	 * For sysio and psycho/psycho+ the IOMMU address space always ends at
    128 	 * 0xffffe000, but the starting address depends on the size of the
    129 	 * map.  The map size is 1024 * 2 ^ is->is_tsbsize entries, where each
    130 	 * entry is 8 bytes.  The start of the map can be calculated by
    131 	 * (0xffffe000 << (8 + is->is_tsbsize)).
    132 	 *
    133 	 * But sabre and hummingbird use a different scheme that seems to
    134 	 * be hard-wired, so we read the start and size from the PROM and
    135 	 * just use those values.
    136 	 */
    137 	is->is_cr = (tsbsize << 16) | IOMMUCR_EN;
    138 	is->is_tsbsize = tsbsize;
    139 	if (iovabase == -1) {
    140 		is->is_dvmabase = IOTSB_VSTART(is->is_tsbsize);
    141 		is->is_dvmaend = IOTSB_VEND - 1;
    142 	} else {
    143 		is->is_dvmabase = iovabase;
    144 		is->is_dvmaend = iovabase + IOTSB_VSIZE(tsbsize) - 1;
    145 	}
    146 
    147 	/*
    148 	 * Allocate memory for I/O pagetables.  They need to be physically
    149 	 * contiguous.
    150 	 */
    151 
    152 	size = PAGE_SIZE << is->is_tsbsize;
    153 	if (uvm_pglistalloc((psize_t)size, (paddr_t)0, (paddr_t)-1,
    154 		(paddr_t)PAGE_SIZE, (paddr_t)0, &pglist, 1, 0) != 0)
    155 		panic("iommu_init: no memory");
    156 
    157 	va = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_VAONLY);
    158 	if (va == 0)
    159 		panic("iommu_init: no memory");
    160 	is->is_tsb = (int64_t *)va;
    161 
    162 	is->is_ptsb = VM_PAGE_TO_PHYS(TAILQ_FIRST(&pglist));
    163 
    164 	/* Map the pages */
    165 	TAILQ_FOREACH(pg, &pglist, pageq.queue) {
    166 		pa = VM_PAGE_TO_PHYS(pg);
    167 		pmap_kenter_pa(va, pa | PMAP_NVC,
    168 		    VM_PROT_READ | VM_PROT_WRITE, 0);
    169 		va += PAGE_SIZE;
    170 	}
    171 	pmap_update(pmap_kernel());
    172 	memset(is->is_tsb, 0, size);
    173 
    174 #ifdef DEBUG
    175 	if (iommudebug & IDB_INFO)
    176 	{
    177 		/* Probe the iommu */
    178 
    179 		printf("iommu regs at: cr=%lx tsb=%lx flush=%lx\n",
    180 			(u_long)bus_space_read_8(is->is_bustag, is->is_iommu,
    181 				offsetof (struct iommureg, iommu_cr)),
    182 			(u_long)bus_space_read_8(is->is_bustag, is->is_iommu,
    183 				offsetof (struct iommureg, iommu_tsb)),
    184 			(u_long)bus_space_read_8(is->is_bustag, is->is_iommu,
    185 				offsetof (struct iommureg, iommu_flush)));
    186 		printf("iommu cr=%llx tsb=%llx\n",
    187 			(unsigned long long)bus_space_read_8(is->is_bustag,
    188 				is->is_iommu,
    189 				offsetof (struct iommureg, iommu_cr)),
    190 			(unsigned long long)bus_space_read_8(is->is_bustag,
    191 				is->is_iommu,
    192 				offsetof (struct iommureg, iommu_tsb)));
    193 		printf("TSB base %p phys %llx\n", (void *)is->is_tsb,
    194 			(unsigned long long)is->is_ptsb);
    195 		delay(1000000); /* 1 s */
    196 	}
    197 #endif
    198 
    199 	/*
    200 	 * now actually start up the IOMMU
    201 	 */
    202 	iommu_reset(is);
    203 
    204 	/*
    205 	 * Now all the hardware's working we need to allocate a dvma map.
    206 	 */
    207 	printf("DVMA map: %x to %x\n",
    208 		(unsigned int)is->is_dvmabase,
    209 		(unsigned int)is->is_dvmaend);
    210 	printf("IOTSB: %llx to %llx\n",
    211 		(unsigned long long)is->is_ptsb,
    212 		(unsigned long long)(is->is_ptsb + size - 1));
    213 	is->is_dvmamap = extent_create(name,
    214 	    is->is_dvmabase, is->is_dvmaend,
    215 	    M_DEVBUF, 0, 0, EX_NOWAIT);
    216 }
    217 
    218 /*
    219  * Streaming buffers don't exist on the UltraSPARC IIi; we should have
    220  * detected that already and disabled them.  If not, we will notice that
    221  * they aren't there when the STRBUF_EN bit does not remain.
    222  */
    223 void
    224 iommu_reset(struct iommu_state *is)
    225 {
    226 	int i;
    227 	struct strbuf_ctl *sb;
    228 
    229 	/* Need to do 64-bit stores */
    230 	bus_space_write_8(is->is_bustag, is->is_iommu, IOMMUREG(iommu_tsb),
    231 		is->is_ptsb);
    232 
    233 	/* Enable IOMMU in diagnostic mode */
    234 	bus_space_write_8(is->is_bustag, is->is_iommu, IOMMUREG(iommu_cr),
    235 		is->is_cr|IOMMUCR_DE);
    236 
    237 	for (i = 0; i < 2; i++) {
    238 		if ((sb = is->is_sb[i])) {
    239 
    240 			/* Enable diagnostics mode? */
    241 			bus_space_write_8(is->is_bustag, is->is_sb[i]->sb_sb,
    242 				STRBUFREG(strbuf_ctl), STRBUF_EN);
    243 
    244 			/* No streaming buffers? Disable them */
    245 			if (bus_space_read_8(is->is_bustag,
    246 				is->is_sb[i]->sb_sb,
    247 				STRBUFREG(strbuf_ctl)) == 0) {
    248 				is->is_sb[i]->sb_flush = NULL;
    249 			} else {
    250 
    251 				/*
    252 				 * locate the pa of the flush buffer.
    253 				 */
    254 				(void)pmap_extract(pmap_kernel(),
    255 					(vaddr_t)is->is_sb[i]->sb_flush,
    256 					&is->is_sb[i]->sb_flushpa);
    257 			}
    258 		}
    259 	}
    260 }
    261 
    262 /*
    263  * Here are the iommu control routines.
    264  */
    265 void
    266 iommu_enter(struct strbuf_ctl *sb, vaddr_t va, int64_t pa, int flags)
    267 {
    268 	struct iommu_state *is = sb->sb_is;
    269 	int strbuf = (flags & BUS_DMA_STREAMING);
    270 	int64_t tte;
    271 
    272 #ifdef DIAGNOSTIC
    273 	if (va < is->is_dvmabase || va > is->is_dvmaend)
    274 		panic("iommu_enter: va %#lx not in DVMA space", va);
    275 #endif
    276 
    277 	/* Is the streamcache flush really needed? */
    278 	if (sb->sb_flush)
    279 		iommu_strbuf_flush(sb, va);
    280 	else
    281 		/* If we can't flush the strbuf don't enable it. */
    282 		strbuf = 0;
    283 
    284 	tte = MAKEIOTTE(pa, !(flags & BUS_DMA_NOWRITE),
    285 		!(flags & BUS_DMA_NOCACHE), (strbuf));
    286 #ifdef DEBUG
    287 	tte |= (flags & 0xff000LL)<<(4*8);
    288 #endif
    289 
    290 	DPRINTF(IDB_IOMMU, ("Clearing TSB slot %d for va %p\n",
    291 		       (int)IOTSBSLOT(va,is->is_tsbsize), (void *)(u_long)va));
    292 	is->is_tsb[IOTSBSLOT(va,is->is_tsbsize)] = tte;
    293 	bus_space_write_8(is->is_bustag, is->is_iommu,
    294 		IOMMUREG(iommu_flush), va);
    295 	DPRINTF(IDB_IOMMU, ("iommu_enter: va %lx pa %lx TSB[%lx]@%p=%lx\n",
    296 		va, (long)pa, (u_long)IOTSBSLOT(va,is->is_tsbsize),
    297 		(void *)(u_long)&is->is_tsb[IOTSBSLOT(va,is->is_tsbsize)],
    298 		(u_long)tte));
    299 }
    300 
    301 /*
    302  * Find the value of a DVMA address (debug routine).
    303  */
    304 paddr_t
    305 iommu_extract(struct iommu_state *is, vaddr_t dva)
    306 {
    307 	int64_t tte = 0;
    308 
    309 	if (dva >= is->is_dvmabase && dva <= is->is_dvmaend)
    310 		tte = is->is_tsb[IOTSBSLOT(dva, is->is_tsbsize)];
    311 
    312 	if ((tte & IOTTE_V) == 0)
    313 		return ((paddr_t)-1L);
    314 	return (tte & IOTTE_PAMASK);
    315 }
    316 
    317 /*
    318  * iommu_remove: removes mappings created by iommu_enter
    319  *
    320  * Only demap from IOMMU if flag is set.
    321  *
    322  * XXX: this function needs better internal error checking.
    323  */
    324 void
    325 iommu_remove(struct iommu_state *is, vaddr_t va, size_t len)
    326 {
    327 
    328 #ifdef DIAGNOSTIC
    329 	if (va < is->is_dvmabase || va > is->is_dvmaend)
    330 		panic("iommu_remove: va 0x%lx not in DVMA space", (u_long)va);
    331 	if ((long)(va + len) < (long)va)
    332 		panic("iommu_remove: va 0x%lx + len 0x%lx wraps",
    333 		      (long) va, (long) len);
    334 	if (len & ~0xfffffff)
    335 		panic("iommu_remove: ridiculous len 0x%lx", (u_long)len);
    336 #endif
    337 
    338 	va = trunc_page(va);
    339 	DPRINTF(IDB_IOMMU, ("iommu_remove: va %lx TSB[%lx]@%p\n",
    340 		va, (u_long)IOTSBSLOT(va, is->is_tsbsize),
    341 		&is->is_tsb[IOTSBSLOT(va, is->is_tsbsize)]));
    342 	while (len > 0) {
    343 		DPRINTF(IDB_IOMMU, ("iommu_remove: clearing TSB slot %d "
    344 			"for va %p size %lx\n",
    345 			(int)IOTSBSLOT(va,is->is_tsbsize), (void *)(u_long)va,
    346 			(u_long)len));
    347 		if (len <= PAGE_SIZE)
    348 			len = 0;
    349 		else
    350 			len -= PAGE_SIZE;
    351 
    352 		/*
    353 		 * XXX Zero-ing the entry would not require RMW
    354 		 *
    355 		 * Disabling valid bit while a page is used by a device
    356 		 * causes an uncorrectable DMA error.
    357 		 * Workaround to avoid an uncorrectable DMA error is
    358 		 * eliminating the next line, but the page is mapped
    359 		 * until the next iommu_enter call.
    360 		 */
    361 		is->is_tsb[IOTSBSLOT(va,is->is_tsbsize)] &= ~IOTTE_V;
    362 		membar_storestore();
    363 		bus_space_write_8(is->is_bustag, is->is_iommu,
    364 			IOMMUREG(iommu_flush), va);
    365 		va += PAGE_SIZE;
    366 	}
    367 }
    368 
    369 static int
    370 iommu_strbuf_flush_done(struct strbuf_ctl *sb)
    371 {
    372 	struct iommu_state *is = sb->sb_is;
    373 	struct timeval cur, flushtimeout;
    374 
    375 #define BUMPTIME(t, usec) { \
    376 	register volatile struct timeval *tp = (t); \
    377 	register long us; \
    378  \
    379 	tp->tv_usec = us = tp->tv_usec + (usec); \
    380 	if (us >= 1000000) { \
    381 		tp->tv_usec = us - 1000000; \
    382 		tp->tv_sec++; \
    383 	} \
    384 }
    385 
    386 	if (!sb->sb_flush)
    387 		return (0);
    388 
    389 	/*
    390 	 * Streaming buffer flushes:
    391 	 *
    392 	 *   1 Tell strbuf to flush by storing va to strbuf_pgflush.  If
    393 	 *     we're not on a cache line boundary (64-bits):
    394 	 *   2 Store 0 in flag
    395 	 *   3 Store pointer to flag in flushsync
    396 	 *   4 wait till flushsync becomes 0x1
    397 	 *
    398 	 * If it takes more than .5 sec, something
    399 	 * went wrong.
    400 	 */
    401 
    402 	*sb->sb_flush = 0;
    403 	bus_space_write_8(is->is_bustag, sb->sb_sb,
    404 		STRBUFREG(strbuf_flushsync), sb->sb_flushpa);
    405 
    406 	microtime(&flushtimeout);
    407 	cur = flushtimeout;
    408 	BUMPTIME(&flushtimeout, 500000); /* 1/2 sec */
    409 
    410 	DPRINTF(IDB_IOMMU, ("iommu_strbuf_flush_done: flush = %lx "
    411 		"at va = %lx pa = %lx now=%"PRIx64":%"PRIx32" until = %"PRIx64":%"PRIx32"\n",
    412 		(long)*sb->sb_flush, (long)sb->sb_flush, (long)sb->sb_flushpa,
    413 		cur.tv_sec, cur.tv_usec,
    414 		flushtimeout.tv_sec, flushtimeout.tv_usec));
    415 
    416 	/* Bypass non-coherent D$ */
    417 	while ((!ldxa(sb->sb_flushpa, ASI_PHYS_CACHED)) &&
    418 		timercmp(&cur, &flushtimeout, <=))
    419 		microtime(&cur);
    420 
    421 #ifdef DIAGNOSTIC
    422 	if (!ldxa(sb->sb_flushpa, ASI_PHYS_CACHED)) {
    423 		printf("iommu_strbuf_flush_done: flush timeout %p, at %p\n",
    424 			(void *)(u_long)*sb->sb_flush,
    425 			(void *)(u_long)sb->sb_flushpa); /* panic? */
    426 #ifdef DDB
    427 		Debugger();
    428 #endif
    429 	}
    430 #endif
    431 	DPRINTF(IDB_IOMMU, ("iommu_strbuf_flush_done: flushed\n"));
    432 	return (*sb->sb_flush);
    433 }
    434 
    435 /*
    436  * IOMMU DVMA operations, common to SBUS and PCI.
    437  */
    438 int
    439 iommu_dvmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
    440 	bus_size_t buflen, struct proc *p, int flags)
    441 {
    442 	struct strbuf_ctl *sb = (struct strbuf_ctl *)map->_dm_cookie;
    443 	struct iommu_state *is = sb->sb_is;
    444 	int s;
    445 	int err, needsflush;
    446 	bus_size_t sgsize;
    447 	paddr_t curaddr;
    448 	u_long dvmaddr, sgstart, sgend, bmask;
    449 	bus_size_t align, boundary, len;
    450 	vaddr_t vaddr = (vaddr_t)buf;
    451 	int seg;
    452 	struct pmap *pmap;
    453 
    454 	if (map->dm_nsegs) {
    455 		/* Already in use?? */
    456 #ifdef DIAGNOSTIC
    457 		printf("iommu_dvmamap_load: map still in use\n");
    458 #endif
    459 		bus_dmamap_unload(t, map);
    460 	}
    461 
    462 	/*
    463 	 * Make sure that on error condition we return "no valid mappings".
    464 	 */
    465 	map->dm_nsegs = 0;
    466 	KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz);
    467 
    468 	if (buflen > map->_dm_size) {
    469 		DPRINTF(IDB_BUSDMA,
    470 		    ("iommu_dvmamap_load(): error %d > %d -- "
    471 		     "map size exceeded!\n", (int)buflen, (int)map->_dm_size));
    472 		return (EINVAL);
    473 	}
    474 
    475 	sgsize = round_page(buflen + ((int)vaddr & PGOFSET));
    476 
    477 	/*
    478 	 * A boundary presented to bus_dmamem_alloc() takes precedence
    479 	 * over boundary in the map.
    480 	 */
    481 	if ((boundary = (map->dm_segs[0]._ds_boundary)) == 0)
    482 		boundary = map->_dm_boundary;
    483 	align = max(map->dm_segs[0]._ds_align, PAGE_SIZE);
    484 
    485 	/*
    486 	 * If our segment size is larger than the boundary we need to
    487 	 * split the transfer up int little pieces ourselves.
    488 	 */
    489 	s = splhigh();
    490 	err = extent_alloc(is->is_dvmamap, sgsize, align,
    491 	    (sgsize > boundary) ? 0 : boundary,
    492 	    EX_NOWAIT|EX_BOUNDZERO, &dvmaddr);
    493 	splx(s);
    494 
    495 #ifdef DEBUG
    496 	if (err || (dvmaddr == (u_long)-1)) {
    497 		printf("iommu_dvmamap_load(): extent_alloc(%d, %x) failed!\n",
    498 		    (int)sgsize, flags);
    499 #ifdef DDB
    500 		Debugger();
    501 #endif
    502 	}
    503 #endif
    504 	if (err != 0)
    505 		return (err);
    506 
    507 	if (dvmaddr == (u_long)-1)
    508 		return (ENOMEM);
    509 
    510 	/* Set the active DVMA map */
    511 	map->_dm_dvmastart = dvmaddr;
    512 	map->_dm_dvmasize = sgsize;
    513 
    514 	/*
    515 	 * Now split the DVMA range into segments, not crossing
    516 	 * the boundary.
    517 	 */
    518 	seg = 0;
    519 	sgstart = dvmaddr + (vaddr & PGOFSET);
    520 	sgend = sgstart + buflen - 1;
    521 	map->dm_segs[seg].ds_addr = sgstart;
    522 	DPRINTF(IDB_INFO, ("iommu_dvmamap_load: boundary %lx boundary - 1 %lx "
    523 	    "~(boundary - 1) %lx\n", (long)boundary, (long)(boundary - 1),
    524 	    (long)~(boundary - 1)));
    525 	bmask = ~(boundary - 1);
    526 	while ((sgstart & bmask) != (sgend & bmask) ||
    527 	       sgend - sgstart + 1 > map->dm_maxsegsz) {
    528 		/* Oops. We crossed a boundary or large seg. Split the xfer. */
    529 		len = map->dm_maxsegsz;
    530 		if ((sgstart & bmask) != (sgend & bmask))
    531 			len = min(len, boundary - (sgstart & (boundary - 1)));
    532 		map->dm_segs[seg].ds_len = len;
    533 		DPRINTF(IDB_INFO, ("iommu_dvmamap_load: "
    534 		    "seg %d start %lx size %lx\n", seg,
    535 		    (long)map->dm_segs[seg].ds_addr,
    536 		    (long)map->dm_segs[seg].ds_len));
    537 		if (++seg >= map->_dm_segcnt) {
    538 			/* Too many segments.  Fail the operation. */
    539 			DPRINTF(IDB_INFO, ("iommu_dvmamap_load: "
    540 			    "too many segments %d\n", seg));
    541 			s = splhigh();
    542 			err = extent_free(is->is_dvmamap,
    543 			    dvmaddr, sgsize, EX_NOWAIT);
    544 			map->_dm_dvmastart = 0;
    545 			map->_dm_dvmasize = 0;
    546 			splx(s);
    547 			if (err != 0)
    548 				printf("warning: %s: %" PRId64
    549 				    " of DVMA space lost\n", __func__, sgsize);
    550 			return (EFBIG);
    551 		}
    552 		sgstart += len;
    553 		map->dm_segs[seg].ds_addr = sgstart;
    554 	}
    555 	map->dm_segs[seg].ds_len = sgend - sgstart + 1;
    556 	DPRINTF(IDB_INFO, ("iommu_dvmamap_load: "
    557 	    "seg %d start %lx size %lx\n", seg,
    558 	    (long)map->dm_segs[seg].ds_addr, (long)map->dm_segs[seg].ds_len));
    559 	map->dm_nsegs = seg + 1;
    560 	map->dm_mapsize = buflen;
    561 
    562 	if (p != NULL)
    563 		pmap = p->p_vmspace->vm_map.pmap;
    564 	else
    565 		pmap = pmap_kernel();
    566 
    567 	needsflush = 0;
    568 	for (; buflen > 0; ) {
    569 
    570 		/*
    571 		 * Get the physical address for this page.
    572 		 */
    573 		if (pmap_extract(pmap, (vaddr_t)vaddr, &curaddr) == FALSE) {
    574 #ifdef DIAGNOSTIC
    575 			printf("iommu_dvmamap_load: pmap_extract failed %lx\n", vaddr);
    576 #endif
    577 			bus_dmamap_unload(t, map);
    578 			return (-1);
    579 		}
    580 
    581 		/*
    582 		 * Compute the segment size, and adjust counts.
    583 		 */
    584 		sgsize = PAGE_SIZE - ((u_long)vaddr & PGOFSET);
    585 		if (buflen < sgsize)
    586 			sgsize = buflen;
    587 
    588 		DPRINTF(IDB_BUSDMA,
    589 		    ("iommu_dvmamap_load: map %p loading va %p "
    590 		    "dva %lx at pa %lx\n",
    591 		    map, (void *)vaddr, (long)dvmaddr,
    592 		    (long)trunc_page(curaddr)));
    593 		iommu_enter(sb, trunc_page(dvmaddr), trunc_page(curaddr),
    594 		    flags | IOTTE_DEBUG(0x4000));
    595 		needsflush = 1;
    596 
    597 		dvmaddr += PAGE_SIZE;
    598 		vaddr += sgsize;
    599 		buflen -= sgsize;
    600 	}
    601 	if (needsflush)
    602 		iommu_strbuf_flush_done(sb);
    603 #ifdef DIAGNOSTIC
    604 	for (seg = 0; seg < map->dm_nsegs; seg++) {
    605 		if (map->dm_segs[seg].ds_addr < is->is_dvmabase ||
    606 			map->dm_segs[seg].ds_addr > is->is_dvmaend) {
    607 			printf("seg %d dvmaddr %lx out of range %x - %x\n",
    608 			    seg, (long)map->dm_segs[seg].ds_addr,
    609 			    is->is_dvmabase, is->is_dvmaend);
    610 #ifdef DDB
    611 			Debugger();
    612 #endif
    613 		}
    614 	}
    615 #endif
    616 	return (0);
    617 }
    618 
    619 
    620 void
    621 iommu_dvmamap_unload(bus_dma_tag_t t, bus_dmamap_t map)
    622 {
    623 	struct strbuf_ctl *sb = (struct strbuf_ctl *)map->_dm_cookie;
    624 	struct iommu_state *is = sb->sb_is;
    625 	int error, s;
    626 	bus_size_t sgsize = map->_dm_dvmasize;
    627 
    628 	/* Flush the iommu */
    629 #ifdef DEBUG
    630 	if (!map->_dm_dvmastart) {
    631 		printf("iommu_dvmamap_unload: No dvmastart is zero\n");
    632 #ifdef DDB
    633 		Debugger();
    634 #endif
    635 	}
    636 #endif
    637 	iommu_remove(is, map->_dm_dvmastart, map->_dm_dvmasize);
    638 
    639 	/* Flush the caches */
    640 	bus_dmamap_unload(t->_parent, map);
    641 
    642 	/* Mark the mappings as invalid. */
    643 	map->dm_mapsize = 0;
    644 	map->dm_nsegs = 0;
    645 
    646 	s = splhigh();
    647 	error = extent_free(is->is_dvmamap, map->_dm_dvmastart,
    648 		map->_dm_dvmasize, EX_NOWAIT);
    649 	map->_dm_dvmastart = 0;
    650 	map->_dm_dvmasize = 0;
    651 	splx(s);
    652 	if (error != 0)
    653 		printf("warning: %s: %" PRId64 " of DVMA space lost\n",
    654 		    __func__, sgsize);
    655 
    656 	/* Clear the map */
    657 }
    658 
    659 
    660 int
    661 iommu_dvmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map,
    662 	bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags)
    663 {
    664 	struct strbuf_ctl *sb = (struct strbuf_ctl *)map->_dm_cookie;
    665 	struct iommu_state *is = sb->sb_is;
    666 	struct vm_page *pg;
    667 	int i, j, s;
    668 	int left;
    669 	int err, needsflush;
    670 	bus_size_t sgsize;
    671 	paddr_t pa;
    672 	bus_size_t boundary, align;
    673 	u_long dvmaddr, sgstart, sgend, bmask;
    674 	struct pglist *pglist;
    675 	const int pagesz = PAGE_SIZE;
    676 #ifdef DEBUG
    677 	int npg = 0;
    678 #endif
    679 
    680 	if (map->dm_nsegs) {
    681 		/* Already in use?? */
    682 #ifdef DIAGNOSTIC
    683 		printf("iommu_dvmamap_load_raw: map still in use\n");
    684 #endif
    685 		bus_dmamap_unload(t, map);
    686 	}
    687 
    688 	/*
    689 	 * A boundary presented to bus_dmamem_alloc() takes precedence
    690 	 * over boundary in the map.
    691 	 */
    692 	if ((boundary = segs[0]._ds_boundary) == 0)
    693 		boundary = map->_dm_boundary;
    694 
    695 	align = max(segs[0]._ds_align, pagesz);
    696 
    697 	/*
    698 	 * Make sure that on error condition we return "no valid mappings".
    699 	 */
    700 	map->dm_nsegs = 0;
    701 	/* Count up the total number of pages we need */
    702 	pa = trunc_page(segs[0].ds_addr);
    703 	sgsize = 0;
    704 	left = size;
    705 	for (i = 0; left > 0 && i < nsegs; i++) {
    706 		if (round_page(pa) != round_page(segs[i].ds_addr))
    707 			sgsize = round_page(sgsize) +
    708 			    (segs[i].ds_addr & PGOFSET);
    709 		sgsize += min(left, segs[i].ds_len);
    710 		left -= segs[i].ds_len;
    711 		pa = segs[i].ds_addr + segs[i].ds_len;
    712 	}
    713 	sgsize = round_page(sgsize);
    714 
    715 	s = splhigh();
    716 	/*
    717 	 * If our segment size is larger than the boundary we need to
    718 	 * split the transfer up into little pieces ourselves.
    719 	 */
    720 	err = extent_alloc(is->is_dvmamap, sgsize, align,
    721 		(sgsize > boundary) ? 0 : boundary,
    722 		((flags & BUS_DMA_NOWAIT) == 0 ? EX_WAITOK : EX_NOWAIT) |
    723 		EX_BOUNDZERO, &dvmaddr);
    724 	splx(s);
    725 
    726 	if (err != 0)
    727 		return (err);
    728 
    729 #ifdef DEBUG
    730 	if (dvmaddr == (u_long)-1)
    731 	{
    732 		printf("iommu_dvmamap_load_raw(): extent_alloc(%d, %x) failed!\n",
    733 		    (int)sgsize, flags);
    734 #ifdef DDB
    735 		Debugger();
    736 #endif
    737 	}
    738 #endif
    739 	if (dvmaddr == (u_long)-1)
    740 		return (ENOMEM);
    741 
    742 	/* Set the active DVMA map */
    743 	map->_dm_dvmastart = dvmaddr;
    744 	map->_dm_dvmasize = sgsize;
    745 
    746 	bmask = ~(boundary - 1);
    747 	if ((pglist = segs[0]._ds_mlist) == NULL) {
    748 		u_long prev_va = 0UL, last_va = dvmaddr;
    749 		paddr_t prev_pa = 0;
    750 		int end = 0, offset;
    751 		bus_size_t len = size;
    752 
    753 		/*
    754 		 * This segs is made up of individual physical
    755 		 *  segments, probably by _bus_dmamap_load_uio() or
    756 		 * _bus_dmamap_load_mbuf().  Ignore the mlist and
    757 		 * load each one individually.
    758 		 */
    759 		j = 0;
    760 		needsflush = 0;
    761 		for (i = 0; i < nsegs ; i++) {
    762 
    763 			pa = segs[i].ds_addr;
    764 			offset = (pa & PGOFSET);
    765 			pa = trunc_page(pa);
    766 			dvmaddr = trunc_page(dvmaddr);
    767 			left = min(len, segs[i].ds_len);
    768 
    769 			DPRINTF(IDB_INFO, ("iommu_dvmamap_load_raw: converting "
    770 				"physseg %d start %lx size %lx\n", i,
    771 				(long)segs[i].ds_addr, (long)segs[i].ds_len));
    772 
    773 			if ((pa == prev_pa) &&
    774 				((offset != 0) || (end != offset))) {
    775 				/* We can re-use this mapping */
    776 				dvmaddr = prev_va;
    777 			}
    778 
    779 			sgstart = dvmaddr + offset;
    780 			sgend = sgstart + left - 1;
    781 
    782 			/* Are the segments virtually adjacent? */
    783 			if ((j > 0) && (end == offset) &&
    784 			    ((offset == 0) || (pa == prev_pa)) &&
    785 			    (map->dm_segs[j-1].ds_len + left <=
    786 			     map->dm_maxsegsz)) {
    787 				/* Just append to the previous segment. */
    788 				map->dm_segs[--j].ds_len += left;
    789 				/* Restore sgstart for boundary check */
    790 				sgstart = map->dm_segs[j].ds_addr;
    791 				DPRINTF(IDB_INFO, ("iommu_dvmamap_load_raw: "
    792 					"appending seg %d start %lx size %lx\n", j,
    793 					(long)map->dm_segs[j].ds_addr,
    794 					(long)map->dm_segs[j].ds_len));
    795 			} else {
    796 				if (j >= map->_dm_segcnt) {
    797 					iommu_remove(is, map->_dm_dvmastart,
    798 					    last_va - map->_dm_dvmastart);
    799 					goto fail;
    800 				}
    801 				map->dm_segs[j].ds_addr = sgstart;
    802 				map->dm_segs[j].ds_len = left;
    803 				DPRINTF(IDB_INFO, ("iommu_dvmamap_load_raw: "
    804 					"seg %d start %lx size %lx\n", j,
    805 					(long)map->dm_segs[j].ds_addr,
    806 					(long)map->dm_segs[j].ds_len));
    807 			}
    808 			end = (offset + left) & PGOFSET;
    809 
    810 			/* Check for boundary issues */
    811 			while ((sgstart & bmask) != (sgend & bmask)) {
    812 				/* Need a new segment. */
    813 				map->dm_segs[j].ds_len =
    814 					boundary - (sgstart & (boundary - 1));
    815 				DPRINTF(IDB_INFO, ("iommu_dvmamap_load_raw: "
    816 					"seg %d start %lx size %lx\n", j,
    817 					(long)map->dm_segs[j].ds_addr,
    818 					(long)map->dm_segs[j].ds_len));
    819 				if (++j >= map->_dm_segcnt) {
    820 					iommu_remove(is, map->_dm_dvmastart,
    821 					    last_va - map->_dm_dvmastart);
    822 					goto fail;
    823 				}
    824 				sgstart += map->dm_segs[j-1].ds_len;
    825 				map->dm_segs[j].ds_addr = sgstart;
    826 				map->dm_segs[j].ds_len = sgend - sgstart + 1;
    827 			}
    828 
    829 			if (sgsize == 0)
    830 				panic("iommu_dmamap_load_raw: size botch");
    831 
    832 			/* Now map a series of pages. */
    833 			while (dvmaddr <= sgend) {
    834 				DPRINTF(IDB_BUSDMA,
    835 					("iommu_dvmamap_load_raw: map %p "
    836 						"loading va %lx at pa %lx\n",
    837 						map, (long)dvmaddr,
    838 						(long)(pa)));
    839 				/* Enter it if we haven't before. */
    840 				if (prev_va != dvmaddr) {
    841 					iommu_enter(sb, prev_va = dvmaddr,
    842 					    prev_pa = pa,
    843 					    flags | IOTTE_DEBUG(++npg << 12));
    844 					needsflush = 1;
    845 				}
    846 				dvmaddr += pagesz;
    847 				pa += pagesz;
    848 				last_va = dvmaddr;
    849 			}
    850 
    851 			len -= left;
    852 			++j;
    853 		}
    854 		if (needsflush)
    855 			iommu_strbuf_flush_done(sb);
    856 
    857 		map->dm_mapsize = size;
    858 		map->dm_nsegs = j;
    859 #ifdef DIAGNOSTIC
    860 		{ int seg;
    861 	for (seg = 0; seg < map->dm_nsegs; seg++) {
    862 		if (map->dm_segs[seg].ds_addr < is->is_dvmabase ||
    863 			map->dm_segs[seg].ds_addr > is->is_dvmaend) {
    864 			printf("seg %d dvmaddr %lx out of range %x - %x\n",
    865 				seg, (long)map->dm_segs[seg].ds_addr,
    866 				is->is_dvmabase, is->is_dvmaend);
    867 #ifdef DDB
    868 			Debugger();
    869 #endif
    870 		}
    871 	}
    872 		}
    873 #endif
    874 		return (0);
    875 	}
    876 
    877 	/*
    878 	 * This was allocated with bus_dmamem_alloc.
    879 	 * The pages are on a `pglist'.
    880 	 */
    881 	i = 0;
    882 	sgstart = dvmaddr;
    883 	sgend = sgstart + size - 1;
    884 	map->dm_segs[i].ds_addr = sgstart;
    885 	while ((sgstart & bmask) != (sgend & bmask)) {
    886 		/* Oops.  We crossed a boundary.  Split the xfer. */
    887 		map->dm_segs[i].ds_len = boundary - (sgstart & (boundary - 1));
    888 		DPRINTF(IDB_INFO, ("iommu_dvmamap_load_raw: "
    889 			"seg %d start %lx size %lx\n", i,
    890 			(long)map->dm_segs[i].ds_addr,
    891 			(long)map->dm_segs[i].ds_len));
    892 		if (++i >= map->_dm_segcnt) {
    893 			/* Too many segments.  Fail the operation. */
    894 			goto fail;
    895 		}
    896 		sgstart += map->dm_segs[i-1].ds_len;
    897 		map->dm_segs[i].ds_addr = sgstart;
    898 	}
    899 	DPRINTF(IDB_INFO, ("iommu_dvmamap_load_raw: "
    900 			"seg %d start %lx size %lx\n", i,
    901 			(long)map->dm_segs[i].ds_addr, (long)map->dm_segs[i].ds_len));
    902 	map->dm_segs[i].ds_len = sgend - sgstart + 1;
    903 
    904 	needsflush = 0;
    905 	TAILQ_FOREACH(pg, pglist, pageq.queue) {
    906 		if (sgsize == 0)
    907 			panic("iommu_dmamap_load_raw: size botch");
    908 		pa = VM_PAGE_TO_PHYS(pg);
    909 
    910 		DPRINTF(IDB_BUSDMA,
    911 		    ("iommu_dvmamap_load_raw: map %p loading va %lx at pa %lx\n",
    912 		    map, (long)dvmaddr, (long)(pa)));
    913 		iommu_enter(sb, dvmaddr, pa, flags | IOTTE_DEBUG(0x8000));
    914 		needsflush = 1;
    915 
    916 		dvmaddr += pagesz;
    917 		sgsize -= pagesz;
    918 	}
    919 	if (needsflush)
    920 		iommu_strbuf_flush_done(sb);
    921 	map->dm_mapsize = size;
    922 	map->dm_nsegs = i+1;
    923 #ifdef DIAGNOSTIC
    924 	{ int seg;
    925 	for (seg = 0; seg < map->dm_nsegs; seg++) {
    926 		if (map->dm_segs[seg].ds_addr < is->is_dvmabase ||
    927 			map->dm_segs[seg].ds_addr > is->is_dvmaend) {
    928 			printf("seg %d dvmaddr %lx out of range %x - %x\n",
    929 				seg, (long)map->dm_segs[seg].ds_addr,
    930 				is->is_dvmabase, is->is_dvmaend);
    931 #ifdef DDB
    932 			Debugger();
    933 #endif
    934 		}
    935 	}
    936 	}
    937 #endif
    938 	return (0);
    939 
    940 fail:
    941 	s = splhigh();
    942 	err = extent_free(is->is_dvmamap, map->_dm_dvmastart, sgsize,
    943 	    EX_NOWAIT);
    944 	map->_dm_dvmastart = 0;
    945 	map->_dm_dvmasize = 0;
    946 	splx(s);
    947 	if (err != 0)
    948 		printf("warning: %s: %" PRId64 " of DVMA space lost\n",
    949 		    __func__, sgsize);
    950 	return (EFBIG);
    951 }
    952 
    953 
    954 /*
    955  * Flush an individual dma segment, returns non-zero if the streaming buffers
    956  * need flushing afterwards.
    957  */
    958 static int
    959 iommu_dvmamap_sync_range(struct strbuf_ctl *sb, vaddr_t va, bus_size_t len)
    960 {
    961 	vaddr_t vaend;
    962 	struct iommu_state *is = sb->sb_is;
    963 
    964 #ifdef DIAGNOSTIC
    965 	if (va < is->is_dvmabase || va > is->is_dvmaend)
    966 		panic("invalid va: %llx", (long long)va);
    967 #endif
    968 
    969 	if ((is->is_tsb[IOTSBSLOT(va, is->is_tsbsize)] & IOTTE_STREAM) == 0) {
    970 		DPRINTF(IDB_BUSDMA,
    971 			("iommu_dvmamap_sync_range: attempting to flush "
    972 			 "non-streaming entry\n"));
    973 		return (0);
    974 	}
    975 
    976 	vaend = round_page(va + len) - 1;
    977 	va = trunc_page(va);
    978 
    979 #ifdef DIAGNOSTIC
    980 	if (va < is->is_dvmabase || vaend > is->is_dvmaend)
    981 		panic("invalid va range: %llx to %llx (%x to %x)",
    982 		    (long long)va, (long long)vaend,
    983 		    is->is_dvmabase,
    984 		    is->is_dvmaend);
    985 #endif
    986 
    987 	for ( ; va <= vaend; va += PAGE_SIZE) {
    988 		DPRINTF(IDB_BUSDMA,
    989 		    ("iommu_dvmamap_sync_range: flushing va %p\n",
    990 		    (void *)(u_long)va));
    991 		iommu_strbuf_flush(sb, va);
    992 	}
    993 
    994 	return (1);
    995 }
    996 
    997 static void
    998 _iommu_dvmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
    999 	bus_size_t len, int ops)
   1000 {
   1001 	struct strbuf_ctl *sb = (struct strbuf_ctl *)map->_dm_cookie;
   1002 	bus_size_t count;
   1003 	int i, needsflush = 0;
   1004 
   1005 	if (!sb->sb_flush)
   1006 		return;
   1007 
   1008 	for (i = 0; i < map->dm_nsegs; i++) {
   1009 		if (offset < map->dm_segs[i].ds_len)
   1010 			break;
   1011 		offset -= map->dm_segs[i].ds_len;
   1012 	}
   1013 
   1014 	if (i == map->dm_nsegs)
   1015 		panic("iommu_dvmamap_sync: segment too short %llu",
   1016 		    (unsigned long long)offset);
   1017 
   1018 	if (ops & (BUS_DMASYNC_PREREAD | BUS_DMASYNC_POSTWRITE)) {
   1019 		/* Nothing to do */;
   1020 	}
   1021 
   1022 	if (ops & (BUS_DMASYNC_POSTREAD | BUS_DMASYNC_PREWRITE)) {
   1023 
   1024 		for (; len > 0 && i < map->dm_nsegs; i++) {
   1025 			count = MIN(map->dm_segs[i].ds_len - offset, len);
   1026 			if (count > 0 &&
   1027 			    iommu_dvmamap_sync_range(sb,
   1028 				map->dm_segs[i].ds_addr + offset, count))
   1029 				needsflush = 1;
   1030 			offset = 0;
   1031 			len -= count;
   1032 		}
   1033 #ifdef DIAGNOSTIC
   1034 		if (i == map->dm_nsegs && len > 0)
   1035 			panic("iommu_dvmamap_sync: leftover %llu",
   1036 			    (unsigned long long)len);
   1037 #endif
   1038 
   1039 		if (needsflush)
   1040 			iommu_strbuf_flush_done(sb);
   1041 	}
   1042 }
   1043 
   1044 void
   1045 iommu_dvmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset,
   1046 	bus_size_t len, int ops)
   1047 {
   1048 
   1049 	/* If len is 0, then there is nothing to do */
   1050 	if (len == 0)
   1051 		return;
   1052 
   1053 	if (ops & (BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE)) {
   1054 		/* Flush the CPU then the IOMMU */
   1055 		bus_dmamap_sync(t->_parent, map, offset, len, ops);
   1056 		_iommu_dvmamap_sync(t, map, offset, len, ops);
   1057 	}
   1058 	if (ops & (BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE)) {
   1059 		/* Flush the IOMMU then the CPU */
   1060 		_iommu_dvmamap_sync(t, map, offset, len, ops);
   1061 		bus_dmamap_sync(t->_parent, map, offset, len, ops);
   1062 	}
   1063 }
   1064 
   1065 int
   1066 iommu_dvmamem_alloc(bus_dma_tag_t t, bus_size_t size, bus_size_t alignment,
   1067 	bus_size_t boundary, bus_dma_segment_t *segs, int nsegs, int *rsegs,
   1068 	int flags)
   1069 {
   1070 
   1071 	DPRINTF(IDB_BUSDMA, ("iommu_dvmamem_alloc: sz %llx align %llx bound %llx "
   1072 	   "segp %p flags %d\n", (unsigned long long)size,
   1073 	   (unsigned long long)alignment, (unsigned long long)boundary,
   1074 	   segs, flags));
   1075 	return (bus_dmamem_alloc(t->_parent, size, alignment, boundary,
   1076 	    segs, nsegs, rsegs, flags|BUS_DMA_DVMA));
   1077 }
   1078 
   1079 void
   1080 iommu_dvmamem_free(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs)
   1081 {
   1082 
   1083 	DPRINTF(IDB_BUSDMA, ("iommu_dvmamem_free: segp %p nsegs %d\n",
   1084 	    segs, nsegs));
   1085 	bus_dmamem_free(t->_parent, segs, nsegs);
   1086 }
   1087 
   1088 /*
   1089  * Map the DVMA mappings into the kernel pmap.
   1090  * Check the flags to see whether we're streaming or coherent.
   1091  */
   1092 int
   1093 iommu_dvmamem_map(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs,
   1094 	size_t size, void **kvap, int flags)
   1095 {
   1096 	struct vm_page *pg;
   1097 	vaddr_t va;
   1098 	bus_addr_t addr;
   1099 	struct pglist *pglist;
   1100 	int cbit;
   1101 	const uvm_flag_t kmflags =
   1102 	    (flags & BUS_DMA_NOWAIT) != 0 ? UVM_KMF_NOWAIT : 0;
   1103 
   1104 	DPRINTF(IDB_BUSDMA, ("iommu_dvmamem_map: segp %p nsegs %d size %lx\n",
   1105 	    segs, nsegs, size));
   1106 
   1107 	/*
   1108 	 * Allocate some space in the kernel map, and then map these pages
   1109 	 * into this space.
   1110 	 */
   1111 	size = round_page(size);
   1112 	va = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_VAONLY | kmflags);
   1113 	if (va == 0)
   1114 		return (ENOMEM);
   1115 
   1116 	*kvap = (void *)va;
   1117 
   1118 	/*
   1119 	 * digest flags:
   1120 	 */
   1121 	cbit = 0;
   1122 	if (flags & BUS_DMA_COHERENT)	/* Disable vcache */
   1123 		cbit |= PMAP_NVC;
   1124 	if (flags & BUS_DMA_NOCACHE)	/* sideffects */
   1125 		cbit |= PMAP_NC;
   1126 
   1127 	/*
   1128 	 * Now take this and map it into the CPU.
   1129 	 */
   1130 	pglist = segs[0]._ds_mlist;
   1131 	TAILQ_FOREACH(pg, pglist, pageq.queue) {
   1132 #ifdef DIAGNOSTIC
   1133 		if (size == 0)
   1134 			panic("iommu_dvmamem_map: size botch");
   1135 #endif
   1136 		addr = VM_PAGE_TO_PHYS(pg);
   1137 		DPRINTF(IDB_BUSDMA, ("iommu_dvmamem_map: "
   1138 		    "mapping va %lx at %llx\n", va, (unsigned long long)addr | cbit));
   1139 		pmap_kenter_pa(va, addr | cbit,
   1140 		    VM_PROT_READ | VM_PROT_WRITE, 0);
   1141 		va += PAGE_SIZE;
   1142 		size -= PAGE_SIZE;
   1143 	}
   1144 	pmap_update(pmap_kernel());
   1145 	return (0);
   1146 }
   1147 
   1148 /*
   1149  * Unmap DVMA mappings from kernel
   1150  */
   1151 void
   1152 iommu_dvmamem_unmap(bus_dma_tag_t t, void *kva, size_t size)
   1153 {
   1154 
   1155 	DPRINTF(IDB_BUSDMA, ("iommu_dvmamem_unmap: kvm %p size %lx\n",
   1156 	    kva, size));
   1157 
   1158 #ifdef DIAGNOSTIC
   1159 	if ((u_long)kva & PGOFSET)
   1160 		panic("iommu_dvmamem_unmap");
   1161 #endif
   1162 
   1163 	size = round_page(size);
   1164 	pmap_kremove((vaddr_t)kva, size);
   1165 	pmap_update(pmap_kernel());
   1166 	uvm_km_free(kernel_map, (vaddr_t)kva, size, UVM_KMF_VAONLY);
   1167 }
   1168