2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1997, 1998 Justin T. Gibbs.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
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.
37 * - M_BUSDMA malloc type
39 * - hw_busdma SYSCTL_NODE
40 * - macros to access the following fields of bus_dma_tag_t:
48 #include <sys/kthread.h>
49 #include <sys/sched.h>
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 */
58 vm_page_t datapage; /* physical page of client data */
60 vm_offset_t dataoffs; /* page offset of client data */
61 bus_size_t datacount; /* client data count */
62 STAILQ_ENTRY(bounce_page) links;
66 STAILQ_ENTRY(bounce_zone) links;
67 STAILQ_HEAD(, bounce_page) bounce_page_list;
68 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
83 struct sysctl_ctx_list sysctl_tree;
84 struct sysctl_oid *sysctl_tree_top;
87 static struct mtx bounce_lock;
88 static int total_bpages;
89 static int busdma_zonecount;
91 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
92 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
94 static MALLOC_DEFINE(M_BOUNCE, "bounce", "busdma bounce pages");
96 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
97 "Total bounce pages");
99 static void busdma_thread(void *);
100 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
104 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
106 struct bounce_zone *bz;
108 /* Reserve Necessary Bounce Pages */
109 mtx_lock(&bounce_lock);
110 if (flags & BUS_DMA_NOWAIT) {
111 if (reserve_bounce_pages(dmat, map, 0) != 0) {
112 map->pagesneeded = 0;
113 mtx_unlock(&bounce_lock);
117 if (reserve_bounce_pages(dmat, map, 1) != 0) {
118 /* Queue us for resources */
119 bz = dmat->bounce_zone;
120 STAILQ_INSERT_TAIL(&bz->bounce_map_waitinglist, map,
122 mtx_unlock(&bounce_lock);
123 return (EINPROGRESS);
126 mtx_unlock(&bounce_lock);
132 init_bounce_pages(void *dummy __unused)
136 STAILQ_INIT(&bounce_zone_list);
137 STAILQ_INIT(&bounce_map_callbacklist);
138 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
140 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
142 static struct sysctl_ctx_list *
143 busdma_sysctl_tree(struct bounce_zone *bz)
146 return (&bz->sysctl_tree);
149 static struct sysctl_oid *
150 busdma_sysctl_tree_top(struct bounce_zone *bz)
153 return (bz->sysctl_tree_top);
157 alloc_bounce_zone(bus_dma_tag_t dmat)
159 struct bounce_zone *bz;
162 /* Check to see if we already have a suitable zone */
163 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
164 if ((dmat_alignment(dmat) <= bz->alignment) &&
166 dmat_domain(dmat) == bz->domain &&
168 (dmat_lowaddr(dmat) >= bz->lowaddr)) {
169 dmat->bounce_zone = bz;
174 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_BUSDMA,
175 M_NOWAIT | M_ZERO)) == NULL)
178 STAILQ_INIT(&bz->bounce_page_list);
179 STAILQ_INIT(&bz->bounce_map_waitinglist);
181 bz->reserved_bpages = 0;
182 bz->active_bpages = 0;
183 bz->lowaddr = dmat_lowaddr(dmat);
184 bz->alignment = MAX(dmat_alignment(dmat), PAGE_SIZE);
187 bz->domain = dmat_domain(dmat);
189 snprintf(bz->zoneid, sizeof(bz->zoneid), "zone%d", busdma_zonecount);
191 snprintf(bz->lowaddrid, sizeof(bz->lowaddrid), "%#jx",
192 (uintmax_t)bz->lowaddr);
193 start_thread = STAILQ_EMPTY(&bounce_zone_list);
194 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
195 dmat->bounce_zone = bz;
197 sysctl_ctx_init(&bz->sysctl_tree);
198 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
199 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
200 CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
201 if (bz->sysctl_tree_top == NULL) {
202 sysctl_ctx_free(&bz->sysctl_tree);
203 return (0); /* XXX error code? */
206 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
207 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
208 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
209 "Total bounce pages");
210 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
211 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
212 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
213 "Free bounce pages");
214 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
215 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
216 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
217 "Reserved bounce pages");
218 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
219 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
220 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
221 "Active bounce pages");
222 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
223 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
224 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
225 "Total bounce requests (pages bounced)");
226 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
227 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
228 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
229 "Total bounce requests that were deferred");
230 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
231 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
232 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
233 SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
234 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
235 "alignment", CTLFLAG_RD, &bz->alignment, "");
237 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
238 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
239 "domain", CTLFLAG_RD, &bz->domain, 0,
244 if (kproc_create(busdma_thread, NULL, NULL, 0, 0, "busdma") !=
246 printf("failed to create busdma thread");
252 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
254 struct bounce_zone *bz;
257 bz = dmat->bounce_zone;
259 while (numpages > 0) {
260 struct bounce_page *bpage;
263 bpage = malloc_domainset(sizeof(*bpage), M_BUSDMA,
264 DOMAINSET_PREF(bz->domain), M_NOWAIT | M_ZERO);
266 bpage = malloc(sizeof(*bpage), M_BUSDMA, M_NOWAIT | M_ZERO);
272 bpage->vaddr = (vm_offset_t)contigmalloc_domainset(PAGE_SIZE,
273 M_BOUNCE, DOMAINSET_PREF(bz->domain), M_NOWAIT,
274 0ul, bz->lowaddr, PAGE_SIZE, 0);
276 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_BOUNCE,
277 M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
279 if (bpage->vaddr == 0) {
280 free(bpage, M_BUSDMA);
283 bpage->busaddr = pmap_kextract(bpage->vaddr);
284 mtx_lock(&bounce_lock);
285 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
289 mtx_unlock(&bounce_lock);
297 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
299 struct bounce_zone *bz;
302 mtx_assert(&bounce_lock, MA_OWNED);
303 bz = dmat->bounce_zone;
304 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
305 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
306 return (map->pagesneeded - (map->pagesreserved + pages));
307 bz->free_bpages -= pages;
308 bz->reserved_bpages += pages;
309 map->pagesreserved += pages;
310 pages = map->pagesneeded - map->pagesreserved;
315 #if defined(__amd64__) || defined(__i386__)
317 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
318 vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size)
321 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
322 bus_addr_t addr, bus_size_t size)
325 struct bounce_zone *bz;
326 struct bounce_page *bpage;
328 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
329 KASSERT(map != NULL, ("add_bounce_page: bad map %p", map));
330 #if defined(__amd64__) || defined(__i386__)
331 KASSERT(map != &nobounce_dmamap, ("add_bounce_page: bad map %p", map));
334 KASSERT((map->flags & DMAMAP_COULD_BOUNCE) != 0,
335 ("add_bounce_page: bad map %p", map));
338 bz = dmat->bounce_zone;
339 if (map->pagesneeded == 0)
340 panic("add_bounce_page: map doesn't need any pages");
343 if (map->pagesreserved == 0)
344 panic("add_bounce_page: map doesn't need any pages");
345 map->pagesreserved--;
347 mtx_lock(&bounce_lock);
348 bpage = STAILQ_FIRST(&bz->bounce_page_list);
350 panic("add_bounce_page: free page list is empty");
352 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
353 bz->reserved_bpages--;
355 mtx_unlock(&bounce_lock);
357 if (dmat_flags(dmat) & BUS_DMA_KEEP_PG_OFFSET) {
358 /* Page offset needs to be preserved. */
359 #if defined(__amd64__) || defined(__i386__)
360 bpage->vaddr |= addr1 & PAGE_MASK;
361 bpage->busaddr |= addr1 & PAGE_MASK;
363 ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
365 bpage->vaddr |= addr & PAGE_MASK;
366 bpage->busaddr |= addr & PAGE_MASK;
369 bpage->datavaddr = vaddr;
370 #if defined(__amd64__) || defined(__i386__)
371 bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
372 KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
373 bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
374 bpage->dataoffs = addr1 & PAGE_MASK;
376 bpage->datapage = PHYS_TO_VM_PAGE(addr);
377 bpage->dataoffs = addr & PAGE_MASK;
379 bpage->datacount = size;
380 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
381 return (bpage->busaddr);
385 free_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
387 struct bounce_page *bpage;
388 struct bounce_zone *bz;
389 bool schedule_thread;
392 if (STAILQ_EMPTY(&map->bpages))
395 bz = dmat->bounce_zone;
397 schedule_thread = false;
398 STAILQ_FOREACH(bpage, &map->bpages, links) {
399 bpage->datavaddr = 0;
400 bpage->datacount = 0;
402 if (dmat_flags(dmat) & BUS_DMA_KEEP_PG_OFFSET) {
404 * Reset the bounce page to start at offset 0.
405 * Other uses of this bounce page may need to
406 * store a full page of data and/or assume it
407 * starts on a page boundary.
409 bpage->vaddr &= ~PAGE_MASK;
410 bpage->busaddr &= ~PAGE_MASK;
415 mtx_lock(&bounce_lock);
416 STAILQ_CONCAT(&bz->bounce_page_list, &map->bpages);
417 bz->free_bpages += count;
418 bz->active_bpages -= count;
419 while ((map = STAILQ_FIRST(&bz->bounce_map_waitinglist)) != NULL) {
420 if (reserve_bounce_pages(map->dmat, map, 1) != 0)
423 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
424 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
425 bz->total_deferred++;
426 schedule_thread = true;
428 mtx_unlock(&bounce_lock);
430 wakeup(&bounce_map_callbacklist);
434 busdma_thread(void *dummy __unused)
436 STAILQ_HEAD(, bus_dmamap) callbacklist;
438 struct bus_dmamap *map, *nmap;
440 thread_lock(curthread);
441 sched_class(curthread, PRI_ITHD);
442 sched_ithread_prio(curthread, PI_SWI(SWI_BUSDMA));
443 thread_unlock(curthread);
445 mtx_lock(&bounce_lock);
446 while (STAILQ_EMPTY(&bounce_map_callbacklist))
447 mtx_sleep(&bounce_map_callbacklist, &bounce_lock, 0,
449 STAILQ_INIT(&callbacklist);
450 STAILQ_CONCAT(&callbacklist, &bounce_map_callbacklist);
451 mtx_unlock(&bounce_lock);
453 STAILQ_FOREACH_SAFE(map, &callbacklist, links, nmap) {
455 dmat_lockfunc(dmat)(dmat_lockfuncarg(dmat),
457 bus_dmamap_load_mem(map->dmat, map, &map->mem,
458 map->callback, map->callback_arg, BUS_DMA_WAITOK);
459 dmat_lockfunc(dmat)(dmat_lockfuncarg(dmat),