2 * Copyright (c) 1997 Justin T. Gibbs.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions, and the following disclaimer,
10 * without modification, immediately at the beginning of the file.
11 * 2. The name of the author may not be used to endorse or promote products
12 * derived from this software without specific prior written permission.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
18 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
35 #include <sys/mutex.h>
37 #include <sys/interrupt.h>
38 #include <sys/memdesc.h>
40 #include <sys/sysctl.h>
44 #include <vm/vm_page.h>
45 #include <vm/vm_map.h>
47 #include <machine/atomic.h>
48 #include <machine/bus.h>
49 #include <machine/md_var.h>
51 #define MAX_BPAGES 1024
59 bus_dma_filter_t *filter;
67 bus_dma_lock_t *lockfunc;
69 bus_dma_segment_t *segments;
73 vm_offset_t vaddr; /* kva of bounce buffer */
74 bus_addr_t busaddr; /* Physical address */
75 vm_offset_t datavaddr; /* kva of client data */
76 bus_addr_t dataaddr; /* client physical address */
77 bus_size_t datacount; /* client data count */
78 STAILQ_ENTRY(bounce_page) links;
81 u_int busdma_swi_pending;
83 static struct mtx bounce_lock;
84 static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
85 static int free_bpages;
86 static int reserved_bpages;
87 static int active_bpages;
88 static int total_bpages;
89 static int total_bounced;
90 static int total_deferred;
92 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
93 SYSCTL_INT(_hw_busdma, OID_AUTO, free_bpages, CTLFLAG_RD, &free_bpages, 0,
95 SYSCTL_INT(_hw_busdma, OID_AUTO, reserved_bpages, CTLFLAG_RD, &reserved_bpages,
96 0, "Reserved bounce pages");
97 SYSCTL_INT(_hw_busdma, OID_AUTO, active_bpages, CTLFLAG_RD, &active_bpages, 0,
98 "Active bounce pages");
99 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
100 "Total bounce pages");
101 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bounced, CTLFLAG_RD, &total_bounced, 0,
102 "Total bounce requests");
103 SYSCTL_INT(_hw_busdma, OID_AUTO, total_deferred, CTLFLAG_RD, &total_deferred,
104 0, "Total bounce requests that were deferred");
107 struct bp_list bpages;
112 bus_dmamap_callback_t *callback;
114 STAILQ_ENTRY(bus_dmamap) links;
117 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
118 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
119 static struct bus_dmamap nobounce_dmamap;
121 static void init_bounce_pages(void *dummy);
122 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
123 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
125 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
126 vm_offset_t vaddr, bus_addr_t addr, bus_size_t size);
127 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
128 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr,
132 * Return true if a match is made.
134 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
136 * If paddr is within the bounds of the dma tag then call the filter callback
137 * to check for a match, if there is no filter callback then assume a match.
140 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr, bus_size_t len)
146 bndy = dmat->boundary;
148 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
149 (paddr & (dmat->alignment - 1)) != 0 ||
150 (paddr & bndy) != ((paddr + len) & bndy)) &&
151 (dmat->filter == NULL ||
152 (*dmat->filter)(dmat->filterarg, paddr) != 0))
155 } while (retval == 0 && dmat != NULL);
160 * Convenience function for manipulating driver locks from busdma (during
161 * busdma_swi, for example). Drivers that don't provide their own locks
162 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own
163 * non-mutex locking scheme don't have to use this at all.
166 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
170 dmtx = (struct mtx *)arg;
179 panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
184 * dflt_lock should never get called. It gets put into the dma tag when
185 * lockfunc == NULL, which is only valid if the maps that are associated
186 * with the tag are meant to never be defered.
187 * XXX Should have a way to identify which driver is responsible here.
190 dflt_lock(void *arg, bus_dma_lock_op_t op)
192 panic("driver error: busdma dflt_lock called");
195 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
198 * Allocate a device specific dma_tag.
201 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
202 bus_size_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
203 bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
204 int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
205 void *lockfuncarg, bus_dma_tag_t *dmat)
207 bus_dma_tag_t newtag;
210 /* Basic sanity checking */
211 if (boundary != 0 && boundary < maxsegsz)
214 /* Return a NULL tag on failure */
217 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
221 newtag->parent = parent;
222 newtag->alignment = alignment;
223 newtag->boundary = boundary;
224 newtag->lowaddr = trunc_page(lowaddr) + (PAGE_SIZE - 1);
225 newtag->highaddr = trunc_page(highaddr) + (PAGE_SIZE - 1);
226 newtag->filter = filter;
227 newtag->filterarg = filterarg;
228 newtag->maxsize = maxsize;
229 newtag->nsegments = nsegments;
230 newtag->maxsegsz = maxsegsz;
231 newtag->flags = flags;
232 newtag->ref_count = 1; /* Count ourself */
233 newtag->map_count = 0;
234 if (lockfunc != NULL) {
235 newtag->lockfunc = lockfunc;
236 newtag->lockfuncarg = lockfuncarg;
238 newtag->lockfunc = dflt_lock;
239 newtag->lockfuncarg = NULL;
241 newtag->segments = NULL;
243 /* Take into account any restrictions imposed by our parent tag */
244 if (parent != NULL) {
245 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
246 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
247 if (newtag->boundary == 0)
248 newtag->boundary = parent->boundary;
249 else if (parent->boundary != 0)
250 newtag->boundary = MIN(parent->boundary,
252 if (newtag->filter == NULL) {
254 * Short circuit looking at our parent directly
255 * since we have encapsulated all of its information
257 newtag->filter = parent->filter;
258 newtag->filterarg = parent->filterarg;
259 newtag->parent = parent->parent;
261 if (newtag->parent != NULL)
262 atomic_add_int(&parent->ref_count, 1);
265 if (newtag->lowaddr < paddr_max && (flags & BUS_DMA_ALLOCNOW) != 0) {
268 if (ptoa(total_bpages) < maxsize) {
271 pages = atop(maxsize) - total_bpages;
273 /* Add pages to our bounce pool */
274 if (alloc_bounce_pages(newtag, pages) < pages)
277 /* Performed initial allocation */
278 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
282 free(newtag, M_DEVBUF);
290 bus_dma_tag_destroy(bus_dma_tag_t dmat)
294 if (dmat->map_count != 0)
297 while (dmat != NULL) {
298 bus_dma_tag_t parent;
300 parent = dmat->parent;
301 atomic_subtract_int(&dmat->ref_count, 1);
302 if (dmat->ref_count == 0) {
303 if (dmat->segments != NULL)
304 free(dmat->segments, M_DEVBUF);
305 free(dmat, M_DEVBUF);
307 * Last reference count, so
308 * release our reference
309 * count on our parent.
320 * Allocate a handle for mapping from kva/uva/physical
321 * address space into bus device space.
324 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
330 if (dmat->segments == NULL) {
331 dmat->segments = (bus_dma_segment_t *)malloc(
332 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
334 if (dmat->segments == NULL)
339 * Bouncing might be required if the driver asks for an active
340 * exclusion region, a data alignment that is stricter than 1, and/or
341 * an active address boundary.
343 if (dmat->lowaddr < paddr_max) {
347 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
352 /* Initialize the new map */
353 STAILQ_INIT(&((*mapp)->bpages));
356 * Attempt to add pages to our pool on a per-instance
357 * basis up to a sane limit.
359 maxpages = MIN(MAX_BPAGES, atop(paddr_max - dmat->lowaddr));
360 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
361 || (dmat->map_count > 0 && total_bpages < maxpages)) {
364 pages = MAX(atop(dmat->maxsize), 1);
365 pages = MIN(maxpages - total_bpages, pages);
366 if (alloc_bounce_pages(dmat, pages) < pages)
369 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
371 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
385 * Destroy a handle for mapping from kva/uva/physical
386 * address space into bus device space.
389 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
392 if (map != NULL && map != &nobounce_dmamap) {
393 if (STAILQ_FIRST(&map->bpages) != NULL)
403 * Allocate a piece of memory that can be efficiently mapped into
404 * bus device space based on the constraints lited in the dma tag.
405 * A dmamap to for use with dmamap_load is also allocated.
408 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
413 if (flags & BUS_DMA_NOWAIT)
418 /* If we succeed, no mapping/bouncing will be required */
421 if (dmat->segments == NULL) {
422 dmat->segments = (bus_dma_segment_t *)malloc(
423 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
425 if (dmat->segments == NULL)
428 if (flags & BUS_DMA_ZERO)
433 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
434 * alignment guarantees of malloc need to be nailed down, and the
435 * code below should be rewritten to take that into account.
437 * In the meantime, we'll warn the user if malloc gets it wrong.
439 if ((dmat->maxsize <= PAGE_SIZE) &&
440 (dmat->alignment < dmat->maxsize) &&
441 dmat->lowaddr >= paddr_max) {
442 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
445 * XXX Use Contigmalloc until it is merged into this facility
446 * and handles multi-seg allocations. Nobody is doing
447 * multi-seg allocations yet though.
448 * XXX Certain AGP hardware does.
450 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
451 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
456 else if (vtophys(*vaddr) & (dmat->alignment - 1))
457 printf("bus_dmamem_alloc failed to align memory properly.\n");
462 * Free a piece of memory and it's allociated dmamap, that was allocated
463 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
466 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
469 * dmamem does not need to be bounced, so the map should be
473 panic("bus_dmamem_free: Invalid map freed\n");
474 if ((dmat->maxsize <= PAGE_SIZE) &&
475 (dmat->alignment < dmat->maxsize) &&
476 dmat->lowaddr >= paddr_max)
477 free(vaddr, M_DEVBUF);
479 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
484 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
485 bus_size_t buflen, int flags)
490 if ((dmat->lowaddr < paddr_max || dmat->boundary > 0 ||
491 dmat->alignment > 1) && map != &nobounce_dmamap &&
492 map->pagesneeded == 0) {
494 * Count the number of bounce pages
495 * needed in order to complete this transfer
498 while (buflen != 0) {
499 sgsize = MIN(buflen, dmat->maxsegsz);
500 if (run_filter(dmat, curaddr, 0) != 0) {
501 sgsize = MIN(sgsize, PAGE_SIZE);
511 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
512 void *buf, bus_size_t buflen, int flags)
515 vm_offset_t vendaddr;
518 if ((dmat->lowaddr < paddr_max || dmat->boundary > 0 ||
519 dmat->alignment > 1) && map != &nobounce_dmamap &&
520 map->pagesneeded == 0) {
522 * Count the number of bounce pages
523 * needed in order to complete this transfer
525 vaddr = trunc_page((vm_offset_t)buf);
526 vendaddr = (vm_offset_t)buf + buflen;
528 while (vaddr < vendaddr) {
529 if (pmap == kernel_pmap)
530 paddr = pmap_kextract(vaddr);
532 paddr = pmap_extract(pmap, vaddr);
533 if (run_filter(dmat, paddr, 0) != 0)
541 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
544 /* Reserve Necessary Bounce Pages */
545 mtx_lock(&bounce_lock);
546 if (flags & BUS_DMA_NOWAIT) {
547 if (reserve_bounce_pages(dmat, map, 0) != 0) {
548 mtx_unlock(&bounce_lock);
552 if (reserve_bounce_pages(dmat, map, 1) != 0) {
553 /* Queue us for resources */
554 STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
556 mtx_unlock(&bounce_lock);
557 return (EINPROGRESS);
560 mtx_unlock(&bounce_lock);
566 * Add a single contiguous physical range to the segment list.
569 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
570 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
572 bus_addr_t baddr, bmask;
576 * Make sure we don't cross any boundaries.
578 bmask = ~(dmat->boundary - 1);
579 if (dmat->boundary > 0) {
580 baddr = (curaddr + dmat->boundary) & bmask;
581 if (sgsize > (baddr - curaddr))
582 sgsize = (baddr - curaddr);
586 * Insert chunk into a segment, coalescing with
587 * previous segment if possible.
592 segs[seg].ds_addr = curaddr;
593 segs[seg].ds_len = sgsize;
595 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
596 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
597 (dmat->boundary == 0 ||
598 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
599 segs[seg].ds_len += sgsize;
601 if (++seg >= dmat->nsegments)
603 segs[seg].ds_addr = curaddr;
604 segs[seg].ds_len = sgsize;
612 * Utility function to load a physical buffer. segp contains
613 * the starting segment on entrace, and the ending segment on exit.
616 _bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
617 vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
625 map = &nobounce_dmamap;
628 segs = dmat->segments;
630 if (map != &nobounce_dmamap) {
631 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
632 if (map->pagesneeded != 0) {
633 error = _bus_dmamap_reserve_pages(dmat, map, flags);
641 sgsize = MIN(buflen, dmat->maxsegsz);
642 if (map->pagesneeded != 0 &&
643 run_filter(dmat, curaddr, sgsize)) {
644 sgsize = MIN(sgsize, PAGE_SIZE);
645 curaddr = add_bounce_page(dmat, map, 0, curaddr,
648 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
659 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
662 * Utility function to load a linear buffer. segp contains
663 * the starting segment on entrace, and the ending segment on exit.
666 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
667 bus_size_t buflen, pmap_t pmap, int flags,
668 bus_dma_segment_t *segs, int *segp)
676 map = &nobounce_dmamap;
679 segs = dmat->segments;
681 if (map != &nobounce_dmamap) {
682 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
683 if (map->pagesneeded != 0) {
684 error = _bus_dmamap_reserve_pages(dmat, map, flags);
690 vaddr = (vm_offset_t)buf;
694 * Get the physical address for this segment.
696 if (pmap == kernel_pmap)
697 curaddr = pmap_kextract(vaddr);
699 curaddr = pmap_extract(pmap, vaddr);
702 * Compute the segment size, and adjust counts.
704 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
705 if (sgsize > dmat->maxsegsz)
706 sgsize = dmat->maxsegsz;
710 if (map->pagesneeded != 0 && run_filter(dmat, curaddr, sgsize))
711 curaddr = add_bounce_page(dmat, map, vaddr, curaddr,
714 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
726 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
731 __bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
732 struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
737 map->callback = callback;
738 map->callback_arg = callback_arg;
743 _bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
744 bus_dma_segment_t *segs, int nsegs, int error)
748 segs = dmat->segments;
753 * Release the mapping held by map.
756 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
758 struct bounce_page *bpage;
760 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
761 STAILQ_REMOVE_HEAD(&map->bpages, links);
762 free_bounce_page(dmat, bpage);
767 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
769 struct bounce_page *bpage;
771 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
773 * Handle data bouncing. We might also
774 * want to add support for invalidating
775 * the caches on broken hardware
778 if (op & BUS_DMASYNC_PREWRITE) {
779 while (bpage != NULL) {
780 if (bpage->datavaddr != 0)
781 bcopy((void *)bpage->datavaddr,
782 (void *)bpage->vaddr,
785 physcopyout(bpage->dataaddr,
786 (void *)bpage->vaddr,
788 bpage = STAILQ_NEXT(bpage, links);
793 if (op & BUS_DMASYNC_POSTREAD) {
794 while (bpage != NULL) {
795 if (bpage->datavaddr != 0)
796 bcopy((void *)bpage->vaddr,
797 (void *)bpage->datavaddr,
800 physcopyin((void *)bpage->vaddr,
803 bpage = STAILQ_NEXT(bpage, links);
811 init_bounce_pages(void *dummy __unused)
818 STAILQ_INIT(&bounce_page_list);
819 STAILQ_INIT(&bounce_map_waitinglist);
820 STAILQ_INIT(&bounce_map_callbacklist);
821 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
823 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
826 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
831 while (numpages > 0) {
832 struct bounce_page *bpage;
834 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
838 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
839 M_NOWAIT, 0ul, dmat->lowaddr, PAGE_SIZE, dmat->boundary);
840 if (bpage->vaddr == 0) {
841 free(bpage, M_DEVBUF);
844 bpage->busaddr = pmap_kextract(bpage->vaddr);
845 mtx_lock(&bounce_lock);
846 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
849 mtx_unlock(&bounce_lock);
857 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
861 mtx_assert(&bounce_lock, MA_OWNED);
862 pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
863 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
864 return (map->pagesneeded - (map->pagesreserved + pages));
865 free_bpages -= pages;
866 reserved_bpages += pages;
867 map->pagesreserved += pages;
868 pages = map->pagesneeded - map->pagesreserved;
874 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
875 bus_addr_t addr, bus_size_t size)
877 struct bounce_page *bpage;
879 KASSERT(map != NULL && map != &nobounce_dmamap,
880 ("add_bounce_page: bad map %p", map));
882 if (map->pagesneeded == 0)
883 panic("add_bounce_page: map doesn't need any pages");
886 if (map->pagesreserved == 0)
887 panic("add_bounce_page: map doesn't need any pages");
888 map->pagesreserved--;
890 mtx_lock(&bounce_lock);
891 bpage = STAILQ_FIRST(&bounce_page_list);
893 panic("add_bounce_page: free page list is empty");
895 STAILQ_REMOVE_HEAD(&bounce_page_list, links);
898 mtx_unlock(&bounce_lock);
900 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
901 /* Page offset needs to be preserved. */
902 bpage->vaddr |= vaddr & PAGE_MASK;
903 bpage->busaddr |= vaddr & PAGE_MASK;
905 bpage->datavaddr = vaddr;
906 bpage->dataaddr = addr;
907 bpage->datacount = size;
908 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
909 return (bpage->busaddr);
913 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
915 struct bus_dmamap *map;
917 bpage->datavaddr = 0;
918 bpage->datacount = 0;
919 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
921 * Reset the bounce page to start at offset 0. Other uses
922 * of this bounce page may need to store a full page of
923 * data and/or assume it starts on a page boundary.
925 bpage->vaddr &= ~PAGE_MASK;
926 bpage->busaddr &= ~PAGE_MASK;
929 mtx_lock(&bounce_lock);
930 STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
933 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
934 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
935 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
936 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map,
938 busdma_swi_pending = 1;
943 mtx_unlock(&bounce_lock);
950 struct bus_dmamap *map;
952 mtx_lock(&bounce_lock);
953 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
954 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
955 mtx_unlock(&bounce_lock);
957 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
958 bus_dmamap_load_mem(map->dmat, map, &map->mem, map->callback,
959 map->callback_arg, BUS_DMA_WAITOK);
960 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
961 mtx_lock(&bounce_lock);
963 mtx_unlock(&bounce_lock);