1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1997, 1998 Justin T. Gibbs.
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 * without modification, immediately at the beginning of the file.
13 * 2. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, 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 * Common code for managing bounce pages for bus_dma backends. As
31 * this code currently assumes it can access internal members of
32 * opaque types like bus_dma_tag_t and bus_dmamap it is #include'd in
33 * backends rather than being compiled standalone.
34 *
35 * Prerequisites:
36 *
37 * - M_BUSDMA malloc type
38 * - struct bus_dmamap
39 * - hw_busdma SYSCTL_NODE
40 * - macros to access the following fields of bus_dma_tag_t:
41 * - dmat_alignment()
42 * - dmat_flags()
43 * - dmat_lowaddr()
44 * - dmat_lockfunc()
45 * - dmat_lockarg()
46 */
47
48 #include <sys/kthread.h>
49 #include <sys/sched.h>
50
51 struct bounce_page {
52 vm_offset_t vaddr; /* kva of bounce buffer */
53 bus_addr_t busaddr; /* Physical address */
54 vm_offset_t datavaddr; /* kva of client data */
55 #if defined(__amd64__) || defined(__i386__)
56 vm_page_t datapage[2]; /* physical page(s) of client data */
57 #else
58 vm_page_t datapage; /* physical page of client data */
59 #endif
60 vm_offset_t dataoffs; /* page offset of client data */
61 bus_size_t datacount; /* client data count */
62 STAILQ_ENTRY(bounce_page) links;
63 };
64
65 struct bounce_zone {
66 STAILQ_ENTRY(bounce_zone) links;
67 STAILQ_HEAD(, bounce_page) bounce_page_list;
68 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
69 int total_bpages;
70 int free_bpages;
71 int reserved_bpages;
72 int active_bpages;
73 int total_bounced;
74 int total_deferred;
75 int map_count;
76 #ifdef dmat_domain
77 int domain;
78 #endif
79 sbintime_t total_deferred_time;
80 bus_size_t alignment;
81 bus_addr_t lowaddr;
82 char zoneid[8];
83 char lowaddrid[20];
84 struct sysctl_ctx_list sysctl_tree;
85 struct sysctl_oid *sysctl_tree_top;
86 };
87
88 static struct mtx bounce_lock;
89 static int total_bpages;
90 static int busdma_zonecount;
91
92 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
93 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
94
95 static MALLOC_DEFINE(M_BOUNCE, "bounce", "busdma bounce pages");
96
97 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
98 "Total bounce pages");
99
100 static void busdma_thread(void *);
101 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
102 int commit);
103
104 static int
_bus_dmamap_reserve_pages(bus_dma_tag_t dmat,bus_dmamap_t map,int flags)105 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
106 {
107 struct bounce_zone *bz;
108
109 /* Reserve Necessary Bounce Pages */
110 mtx_lock(&bounce_lock);
111 if (flags & BUS_DMA_NOWAIT) {
112 if (reserve_bounce_pages(dmat, map, 0) != 0) {
113 map->pagesneeded = 0;
114 mtx_unlock(&bounce_lock);
115 return (ENOMEM);
116 }
117 } else {
118 if (reserve_bounce_pages(dmat, map, 1) != 0) {
119 /* Queue us for resources */
120 bz = dmat->bounce_zone;
121 STAILQ_INSERT_TAIL(&bz->bounce_map_waitinglist, map,
122 links);
123 map->queued_time = sbinuptime();
124 mtx_unlock(&bounce_lock);
125 return (EINPROGRESS);
126 }
127 }
128 mtx_unlock(&bounce_lock);
129
130 return (0);
131 }
132
133 static void
init_bounce_pages(void * dummy __unused)134 init_bounce_pages(void *dummy __unused)
135 {
136
137 total_bpages = 0;
138 STAILQ_INIT(&bounce_zone_list);
139 STAILQ_INIT(&bounce_map_callbacklist);
140 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
141 }
142 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
143
144 static struct sysctl_ctx_list *
busdma_sysctl_tree(struct bounce_zone * bz)145 busdma_sysctl_tree(struct bounce_zone *bz)
146 {
147
148 return (&bz->sysctl_tree);
149 }
150
151 static struct sysctl_oid *
busdma_sysctl_tree_top(struct bounce_zone * bz)152 busdma_sysctl_tree_top(struct bounce_zone *bz)
153 {
154
155 return (bz->sysctl_tree_top);
156 }
157
158 /*
159 * Returns true if the address falls within the tag's exclusion window, or
160 * fails to meet its alignment requirements.
161 */
162 static bool
addr_needs_bounce(bus_dma_tag_t dmat,bus_addr_t paddr)163 addr_needs_bounce(bus_dma_tag_t dmat, bus_addr_t paddr)
164 {
165
166 if (paddr > dmat_lowaddr(dmat) && paddr <= dmat_highaddr(dmat))
167 return (true);
168 if (!vm_addr_align_ok(paddr, dmat_alignment(dmat)))
169 return (true);
170
171 return (false);
172 }
173
174 static int
alloc_bounce_zone(bus_dma_tag_t dmat)175 alloc_bounce_zone(bus_dma_tag_t dmat)
176 {
177 struct bounce_zone *bz;
178 bool start_thread;
179
180 /* Check to see if we already have a suitable zone */
181 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
182 if ((dmat_alignment(dmat) <= bz->alignment) &&
183 #ifdef dmat_domain
184 dmat_domain(dmat) == bz->domain &&
185 #endif
186 (dmat_lowaddr(dmat) >= bz->lowaddr)) {
187 dmat->bounce_zone = bz;
188 return (0);
189 }
190 }
191
192 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_BUSDMA,
193 M_NOWAIT | M_ZERO)) == NULL)
194 return (ENOMEM);
195
196 STAILQ_INIT(&bz->bounce_page_list);
197 STAILQ_INIT(&bz->bounce_map_waitinglist);
198 bz->free_bpages = 0;
199 bz->reserved_bpages = 0;
200 bz->active_bpages = 0;
201 bz->lowaddr = dmat_lowaddr(dmat);
202 bz->alignment = MAX(dmat_alignment(dmat), PAGE_SIZE);
203 bz->map_count = 0;
204 #ifdef dmat_domain
205 bz->domain = dmat_domain(dmat);
206 #endif
207 snprintf(bz->zoneid, sizeof(bz->zoneid), "zone%d", busdma_zonecount);
208 busdma_zonecount++;
209 snprintf(bz->lowaddrid, sizeof(bz->lowaddrid), "%#jx",
210 (uintmax_t)bz->lowaddr);
211 start_thread = STAILQ_EMPTY(&bounce_zone_list);
212 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
213 dmat->bounce_zone = bz;
214
215 sysctl_ctx_init(&bz->sysctl_tree);
216 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
217 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
218 CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
219 if (bz->sysctl_tree_top == NULL) {
220 sysctl_ctx_free(&bz->sysctl_tree);
221 return (0); /* XXX error code? */
222 }
223
224 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
225 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
226 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
227 "Total bounce pages");
228 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
229 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
230 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
231 "Free bounce pages");
232 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
233 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
234 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
235 "Reserved bounce pages");
236 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
237 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
238 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
239 "Active bounce pages");
240 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
241 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
242 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
243 "Total bounce requests (pages bounced)");
244 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
245 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
246 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
247 "Total bounce requests that were deferred");
248 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
249 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
250 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
251 SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
252 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
253 "alignment", CTLFLAG_RD, &bz->alignment, "");
254 #ifdef dmat_domain
255 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
256 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
257 "domain", CTLFLAG_RD, &bz->domain, 0,
258 "memory domain");
259 #endif
260 SYSCTL_ADD_SBINTIME_USEC(busdma_sysctl_tree(bz),
261 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
262 "total_deferred_time", CTLFLAG_RD, &bz->total_deferred_time,
263 "Cumulative time busdma requests are deferred (us)");
264 if (start_thread) {
265 if (kproc_create(busdma_thread, NULL, NULL, 0, 0, "busdma") !=
266 0)
267 printf("failed to create busdma thread");
268 }
269 return (0);
270 }
271
272 static int
alloc_bounce_pages(bus_dma_tag_t dmat,u_int numpages)273 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
274 {
275 struct bounce_zone *bz;
276 int count;
277
278 bz = dmat->bounce_zone;
279 count = 0;
280 while (numpages > 0) {
281 struct bounce_page *bpage;
282
283 #ifdef dmat_domain
284 bpage = malloc_domainset(sizeof(*bpage), M_BUSDMA,
285 DOMAINSET_PREF(bz->domain), M_NOWAIT | M_ZERO);
286 #else
287 bpage = malloc(sizeof(*bpage), M_BUSDMA, M_NOWAIT | M_ZERO);
288 #endif
289
290 if (bpage == NULL)
291 break;
292 #ifdef dmat_domain
293 bpage->vaddr = (vm_offset_t)contigmalloc_domainset(PAGE_SIZE,
294 M_BOUNCE, DOMAINSET_PREF(bz->domain), M_NOWAIT,
295 0ul, bz->lowaddr, PAGE_SIZE, 0);
296 #else
297 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_BOUNCE,
298 M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
299 #endif
300 if (bpage->vaddr == 0) {
301 free(bpage, M_BUSDMA);
302 break;
303 }
304 bpage->busaddr = pmap_kextract(bpage->vaddr);
305 mtx_lock(&bounce_lock);
306 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
307 total_bpages++;
308 bz->total_bpages++;
309 bz->free_bpages++;
310 mtx_unlock(&bounce_lock);
311 count++;
312 numpages--;
313 }
314 return (count);
315 }
316
317 static int
reserve_bounce_pages(bus_dma_tag_t dmat,bus_dmamap_t map,int commit)318 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
319 {
320 struct bounce_zone *bz;
321 int pages;
322
323 mtx_assert(&bounce_lock, MA_OWNED);
324 bz = dmat->bounce_zone;
325 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
326 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
327 return (map->pagesneeded - (map->pagesreserved + pages));
328 bz->free_bpages -= pages;
329 bz->reserved_bpages += pages;
330 map->pagesreserved += pages;
331 pages = map->pagesneeded - map->pagesreserved;
332
333 return (pages);
334 }
335
336 #if defined(__amd64__) || defined(__i386__)
337 static bus_addr_t
add_bounce_page(bus_dma_tag_t dmat,bus_dmamap_t map,vm_offset_t vaddr,vm_paddr_t addr1,vm_paddr_t addr2,bus_size_t size)338 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
339 vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size)
340 #else
341 static bus_addr_t
342 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
343 bus_addr_t addr, bus_size_t size)
344 #endif
345 {
346 struct bounce_zone *bz;
347 struct bounce_page *bpage;
348
349 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
350 KASSERT(map != NULL, ("add_bounce_page: bad map %p", map));
351 #if defined(__amd64__) || defined(__i386__)
352 KASSERT(map != &nobounce_dmamap, ("add_bounce_page: bad map %p", map));
353 #endif
354 #ifdef __riscv
355 KASSERT((map->flags & DMAMAP_COULD_BOUNCE) != 0,
356 ("add_bounce_page: bad map %p", map));
357 #endif
358
359 bz = dmat->bounce_zone;
360 if (map->pagesneeded == 0)
361 panic("add_bounce_page: map doesn't need any pages");
362 map->pagesneeded--;
363
364 if (map->pagesreserved == 0)
365 panic("add_bounce_page: map doesn't need any pages");
366 map->pagesreserved--;
367
368 mtx_lock(&bounce_lock);
369 bpage = STAILQ_FIRST(&bz->bounce_page_list);
370 if (bpage == NULL)
371 panic("add_bounce_page: free page list is empty");
372
373 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
374 bz->reserved_bpages--;
375 bz->active_bpages++;
376 mtx_unlock(&bounce_lock);
377
378 if (dmat_flags(dmat) & BUS_DMA_KEEP_PG_OFFSET) {
379 /* Page offset needs to be preserved. */
380 #if defined(__amd64__) || defined(__i386__)
381 bpage->vaddr |= addr1 & PAGE_MASK;
382 bpage->busaddr |= addr1 & PAGE_MASK;
383 KASSERT(addr2 == 0,
384 ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
385 #else
386 bpage->vaddr |= addr & PAGE_MASK;
387 bpage->busaddr |= addr & PAGE_MASK;
388 #endif
389 }
390 bpage->datavaddr = vaddr;
391 #if defined(__amd64__) || defined(__i386__)
392 bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
393 KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
394 bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
395 bpage->dataoffs = addr1 & PAGE_MASK;
396 #else
397 bpage->datapage = PHYS_TO_VM_PAGE(addr);
398 bpage->dataoffs = addr & PAGE_MASK;
399 #endif
400 bpage->datacount = size;
401 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
402 return (bpage->busaddr);
403 }
404
405 static void
free_bounce_pages(bus_dma_tag_t dmat,bus_dmamap_t map)406 free_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
407 {
408 struct bounce_page *bpage;
409 struct bounce_zone *bz;
410 bool schedule_thread;
411 u_int count;
412
413 if (STAILQ_EMPTY(&map->bpages))
414 return;
415
416 bz = dmat->bounce_zone;
417 count = 0;
418 schedule_thread = false;
419 STAILQ_FOREACH(bpage, &map->bpages, links) {
420 bpage->datavaddr = 0;
421 bpage->datacount = 0;
422
423 if (dmat_flags(dmat) & BUS_DMA_KEEP_PG_OFFSET) {
424 /*
425 * Reset the bounce page to start at offset 0.
426 * Other uses of this bounce page may need to
427 * store a full page of data and/or assume it
428 * starts on a page boundary.
429 */
430 bpage->vaddr &= ~PAGE_MASK;
431 bpage->busaddr &= ~PAGE_MASK;
432 }
433 count++;
434 }
435
436 mtx_lock(&bounce_lock);
437 STAILQ_CONCAT(&bz->bounce_page_list, &map->bpages);
438 bz->free_bpages += count;
439 bz->active_bpages -= count;
440 while ((map = STAILQ_FIRST(&bz->bounce_map_waitinglist)) != NULL) {
441 if (reserve_bounce_pages(map->dmat, map, 1) != 0)
442 break;
443
444 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
445 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
446 bz->total_deferred++;
447 schedule_thread = true;
448 }
449 mtx_unlock(&bounce_lock);
450 if (schedule_thread)
451 wakeup(&bounce_map_callbacklist);
452 }
453
454 /*
455 * Add a single contiguous physical range to the segment list.
456 */
457 static bus_size_t
_bus_dmamap_addseg(bus_dma_tag_t dmat,bus_dmamap_t map,bus_addr_t curaddr,bus_size_t sgsize,bus_dma_segment_t * segs,int * segp)458 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
459 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
460 {
461 int seg;
462
463 KASSERT(curaddr <= BUS_SPACE_MAXADDR,
464 ("ds_addr %#jx > BUS_SPACE_MAXADDR %#jx; dmat %p fl %#x low %#jx "
465 "hi %#jx",
466 (uintmax_t)curaddr, (uintmax_t)BUS_SPACE_MAXADDR,
467 dmat, dmat_bounce_flags(dmat), (uintmax_t)dmat_lowaddr(dmat),
468 (uintmax_t)dmat_highaddr(dmat)));
469
470 /*
471 * Make sure we don't cross any boundaries.
472 */
473 if (!vm_addr_bound_ok(curaddr, sgsize, dmat_boundary(dmat)))
474 sgsize = roundup2(curaddr, dmat_boundary(dmat)) - curaddr;
475
476 /*
477 * Insert chunk into a segment, coalescing with
478 * previous segment if possible.
479 */
480 seg = *segp;
481 if (seg == -1) {
482 seg = 0;
483 segs[seg].ds_addr = curaddr;
484 segs[seg].ds_len = sgsize;
485 } else {
486 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
487 (segs[seg].ds_len + sgsize) <= dmat_maxsegsz(dmat) &&
488 vm_addr_bound_ok(segs[seg].ds_addr,
489 segs[seg].ds_len + sgsize, dmat_boundary(dmat)))
490 segs[seg].ds_len += sgsize;
491 else {
492 if (++seg >= dmat_nsegments(dmat))
493 return (0);
494 segs[seg].ds_addr = curaddr;
495 segs[seg].ds_len = sgsize;
496 }
497 }
498 *segp = seg;
499 return (sgsize);
500 }
501
502 /*
503 * Add a contiguous physical range to the segment list, respecting the tag's
504 * maximum segment size and splitting it into multiple segments as necessary.
505 */
506 static bool
_bus_dmamap_addsegs(bus_dma_tag_t dmat,bus_dmamap_t map,bus_addr_t curaddr,bus_size_t sgsize,bus_dma_segment_t * segs,int * segp)507 _bus_dmamap_addsegs(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
508 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
509 {
510 bus_size_t done, todo;
511
512 while (sgsize > 0) {
513 todo = MIN(sgsize, dmat_maxsegsz(dmat));
514 done = _bus_dmamap_addseg(dmat, map, curaddr, todo, segs,
515 segp);
516 if (done == 0)
517 return (false);
518 curaddr += done;
519 sgsize -= done;
520 }
521 return (true);
522 }
523
524 static void
busdma_thread(void * dummy __unused)525 busdma_thread(void *dummy __unused)
526 {
527 STAILQ_HEAD(, bus_dmamap) callbacklist;
528 bus_dma_tag_t dmat;
529 struct bus_dmamap *map, *nmap;
530 struct bounce_zone *bz;
531
532 thread_lock(curthread);
533 sched_class(curthread, PRI_ITHD);
534 sched_ithread_prio(curthread, PI_SWI(SWI_BUSDMA));
535 thread_unlock(curthread);
536 for (;;) {
537 mtx_lock(&bounce_lock);
538 while (STAILQ_EMPTY(&bounce_map_callbacklist))
539 mtx_sleep(&bounce_map_callbacklist, &bounce_lock, 0,
540 "-", 0);
541 STAILQ_INIT(&callbacklist);
542 STAILQ_CONCAT(&callbacklist, &bounce_map_callbacklist);
543 mtx_unlock(&bounce_lock);
544
545 STAILQ_FOREACH_SAFE(map, &callbacklist, links, nmap) {
546 dmat = map->dmat;
547 bz = dmat->bounce_zone;
548 dmat_lockfunc(dmat)(dmat_lockfuncarg(dmat),
549 BUS_DMA_LOCK);
550 bz->total_deferred_time += (sbinuptime() - map->queued_time);
551 bus_dmamap_load_mem(map->dmat, map, &map->mem,
552 map->callback, map->callback_arg, BUS_DMA_WAITOK);
553 dmat_lockfunc(dmat)(dmat_lockfuncarg(dmat),
554 BUS_DMA_UNLOCK);
555 }
556 }
557 }
558