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>
36 #include <sys/mutex.h>
38 #include <sys/interrupt.h>
41 #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_size_t datacount; /* client data count */
77 STAILQ_ENTRY(bounce_page) links;
80 u_int busdma_swi_pending;
82 static struct mtx bounce_lock;
83 static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
84 static int free_bpages;
85 static int reserved_bpages;
86 static int active_bpages;
87 static int total_bpages;
88 static int total_bounced;
89 static int total_deferred;
91 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
92 SYSCTL_INT(_hw_busdma, OID_AUTO, free_bpages, CTLFLAG_RD, &free_bpages, 0,
94 SYSCTL_INT(_hw_busdma, OID_AUTO, reserved_bpages, CTLFLAG_RD, &reserved_bpages,
95 0, "Reserved bounce pages");
96 SYSCTL_INT(_hw_busdma, OID_AUTO, active_bpages, CTLFLAG_RD, &active_bpages, 0,
97 "Active bounce pages");
98 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
99 "Total bounce pages");
100 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bounced, CTLFLAG_RD, &total_bounced, 0,
101 "Total bounce requests");
102 SYSCTL_INT(_hw_busdma, OID_AUTO, total_deferred, CTLFLAG_RD, &total_deferred,
103 0, "Total bounce requests that were deferred");
106 struct bp_list bpages;
110 void *buf; /* unmapped buffer pointer */
111 bus_size_t buflen; /* unmapped buffer length */
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_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 < ptoa(Maxmem) && (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 < ptoa(Maxmem)) {
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, Maxmem - atop(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 >= ptoa(Maxmem)) {
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 >= ptoa(Maxmem))
477 free(vaddr, M_DEVBUF);
479 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
484 * Utility function to load a linear buffer. lastaddrp holds state
485 * between invocations (for multiple-buffer loads). segp contains
486 * the starting segment on entrace, and the ending segment on exit.
487 * first indicates if this is the first invocation of this function.
490 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
491 bus_size_t buflen, struct thread *td, int flags, bus_addr_t *lastaddrp,
492 bus_dma_segment_t *segs, int *segp, int first)
495 bus_addr_t curaddr, lastaddr, baddr, bmask;
502 map = &nobounce_dmamap;
505 pmap = vmspace_pmap(td->td_proc->p_vmspace);
509 if ((dmat->lowaddr < ptoa(Maxmem) || dmat->boundary > 0 ||
510 dmat->alignment > 1) && map != &nobounce_dmamap &&
511 map->pagesneeded == 0) {
512 vm_offset_t vendaddr;
515 * Count the number of bounce pages
516 * needed in order to complete this transfer
518 vaddr = trunc_page((vm_offset_t)buf);
519 vendaddr = (vm_offset_t)buf + buflen;
521 while (vaddr < vendaddr) {
523 paddr = pmap_extract(pmap, vaddr);
525 paddr = pmap_kextract(vaddr);
526 if (run_filter(dmat, paddr, 0) != 0)
532 vaddr = (vm_offset_t)buf;
534 /* Reserve Necessary Bounce Pages */
535 if (map->pagesneeded != 0) {
536 mtx_lock(&bounce_lock);
537 if (flags & BUS_DMA_NOWAIT) {
538 if (reserve_bounce_pages(dmat, map, 0) != 0) {
539 mtx_unlock(&bounce_lock);
543 if (reserve_bounce_pages(dmat, map, 1) != 0) {
544 /* Queue us for resources */
547 map->buflen = buflen;
548 STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
550 mtx_unlock(&bounce_lock);
551 return (EINPROGRESS);
554 mtx_unlock(&bounce_lock);
557 lastaddr = *lastaddrp;
558 bmask = ~(dmat->boundary - 1);
560 for (seg = *segp; buflen > 0 ; ) {
562 * Get the physical address for this segment.
565 curaddr = pmap_extract(pmap, vaddr);
567 curaddr = pmap_kextract(vaddr);
570 * Compute the segment size, and adjust counts.
572 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
573 if (sgsize > dmat->maxsegsz)
574 sgsize = dmat->maxsegsz;
579 * Make sure we don't cross any boundaries.
581 if (dmat->boundary > 0) {
582 baddr = (curaddr + dmat->boundary) & bmask;
583 if (sgsize > (baddr - curaddr))
584 sgsize = (baddr - curaddr);
587 if (map->pagesneeded != 0 && run_filter(dmat, curaddr, sgsize))
588 curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
591 * Insert chunk into a segment, coalescing with
592 * previous segment if possible.
595 segs[seg].ds_addr = curaddr;
596 segs[seg].ds_len = sgsize;
599 if (curaddr == lastaddr &&
600 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
601 (dmat->boundary == 0 ||
602 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
603 segs[seg].ds_len += sgsize;
605 if (++seg >= dmat->nsegments)
607 segs[seg].ds_addr = curaddr;
608 segs[seg].ds_len = sgsize;
612 lastaddr = curaddr + sgsize;
618 *lastaddrp = lastaddr;
623 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
627 * Map the buffer buf into bus space using the dmamap map.
630 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
631 bus_size_t buflen, bus_dmamap_callback_t *callback, void *callback_arg,
634 bus_addr_t lastaddr = 0;
635 int error, nsegs = 0;
638 flags |= BUS_DMA_WAITOK;
639 map->callback = callback;
640 map->callback_arg = callback_arg;
643 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
644 &lastaddr, dmat->segments, &nsegs, 1);
646 if (error == EINPROGRESS)
650 (*callback)(callback_arg, dmat->segments, 0, error);
652 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
658 * Like _bus_dmamap_load(), but for mbufs.
661 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
662 bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
668 flags |= BUS_DMA_NOWAIT;
671 if (m0->m_pkthdr.len <= dmat->maxsize) {
673 bus_addr_t lastaddr = 0;
676 for (m = m0; m != NULL && error == 0; m = m->m_next) {
678 error = _bus_dmamap_load_buffer(dmat, map,
679 m->m_data, m->m_len, NULL, flags,
680 &lastaddr, dmat->segments, &nsegs, first);
689 /* force "no valid mappings" in callback */
690 (*callback)(callback_arg, dmat->segments, 0, 0, error);
692 (*callback)(callback_arg, dmat->segments, nsegs + 1,
693 m0->m_pkthdr.len, error);
699 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
700 bus_dma_segment_t *segs, int *nsegs, int flags)
706 flags |= BUS_DMA_NOWAIT;
709 if (m0->m_pkthdr.len <= dmat->maxsize) {
711 bus_addr_t lastaddr = 0;
714 for (m = m0; m != NULL && error == 0; m = m->m_next) {
716 error = _bus_dmamap_load_buffer(dmat, map,
717 m->m_data, m->m_len, NULL, flags,
718 &lastaddr, segs, nsegs, first);
731 * Like _bus_dmamap_load(), but for uios.
734 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
735 bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
738 int nsegs, error, first, i;
741 struct thread *td = NULL;
743 flags |= BUS_DMA_NOWAIT;
744 resid = uio->uio_resid;
747 if (uio->uio_segflg == UIO_USERSPACE) {
750 ("bus_dmamap_load_uio: USERSPACE but no proc"));
756 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
758 * Now at the first iovec to load. Load each iovec
759 * until we have exhausted the residual count.
762 resid < iov[i].iov_len ? resid : iov[i].iov_len;
763 caddr_t addr = (caddr_t) iov[i].iov_base;
766 error = _bus_dmamap_load_buffer(dmat, map, addr,
767 minlen, td, flags, &lastaddr, dmat->segments,
776 /* force "no valid mappings" in callback */
777 (*callback)(callback_arg, dmat->segments, 0, 0, error);
779 (*callback)(callback_arg, dmat->segments, nsegs + 1,
780 uio->uio_resid, error);
786 * Release the mapping held by map.
789 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
791 struct bounce_page *bpage;
793 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
794 STAILQ_REMOVE_HEAD(&map->bpages, links);
795 free_bounce_page(dmat, bpage);
800 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
802 struct bounce_page *bpage;
804 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
806 * Handle data bouncing. We might also
807 * want to add support for invalidating
808 * the caches on broken hardware
811 if (op & BUS_DMASYNC_PREWRITE) {
812 while (bpage != NULL) {
813 bcopy((void *)bpage->datavaddr,
814 (void *)bpage->vaddr, bpage->datacount);
815 bpage = STAILQ_NEXT(bpage, links);
820 if (op & BUS_DMASYNC_POSTREAD) {
821 while (bpage != NULL) {
822 bcopy((void *)bpage->vaddr,
823 (void *)bpage->datavaddr, bpage->datacount);
824 bpage = STAILQ_NEXT(bpage, links);
832 init_bounce_pages(void *dummy __unused)
839 STAILQ_INIT(&bounce_page_list);
840 STAILQ_INIT(&bounce_map_waitinglist);
841 STAILQ_INIT(&bounce_map_callbacklist);
842 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
844 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
847 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
852 while (numpages > 0) {
853 struct bounce_page *bpage;
855 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
859 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
860 M_NOWAIT, 0ul, dmat->lowaddr, PAGE_SIZE, dmat->boundary);
861 if (bpage->vaddr == 0) {
862 free(bpage, M_DEVBUF);
865 bpage->busaddr = pmap_kextract(bpage->vaddr);
866 mtx_lock(&bounce_lock);
867 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
870 mtx_unlock(&bounce_lock);
878 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
882 mtx_assert(&bounce_lock, MA_OWNED);
883 pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
884 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
885 return (map->pagesneeded - (map->pagesreserved + pages));
886 free_bpages -= pages;
887 reserved_bpages += pages;
888 map->pagesreserved += pages;
889 pages = map->pagesneeded - map->pagesreserved;
895 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
898 struct bounce_page *bpage;
900 KASSERT(map != NULL && map != &nobounce_dmamap,
901 ("add_bounce_page: bad map %p", map));
903 if (map->pagesneeded == 0)
904 panic("add_bounce_page: map doesn't need any pages");
907 if (map->pagesreserved == 0)
908 panic("add_bounce_page: map doesn't need any pages");
909 map->pagesreserved--;
911 mtx_lock(&bounce_lock);
912 bpage = STAILQ_FIRST(&bounce_page_list);
914 panic("add_bounce_page: free page list is empty");
916 STAILQ_REMOVE_HEAD(&bounce_page_list, links);
919 mtx_unlock(&bounce_lock);
921 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
922 /* Page offset needs to be preserved. */
923 bpage->vaddr |= vaddr & PAGE_MASK;
924 bpage->busaddr |= vaddr & PAGE_MASK;
926 bpage->datavaddr = vaddr;
927 bpage->datacount = size;
928 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
929 return (bpage->busaddr);
933 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
935 struct bus_dmamap *map;
937 bpage->datavaddr = 0;
938 bpage->datacount = 0;
939 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
941 * Reset the bounce page to start at offset 0. Other uses
942 * of this bounce page may need to store a full page of
943 * data and/or assume it starts on a page boundary.
945 bpage->vaddr &= ~PAGE_MASK;
946 bpage->busaddr &= ~PAGE_MASK;
949 mtx_lock(&bounce_lock);
950 STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
953 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
954 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
955 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
956 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map,
958 busdma_swi_pending = 1;
963 mtx_unlock(&bounce_lock);
970 struct bus_dmamap *map;
972 mtx_lock(&bounce_lock);
973 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
974 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
975 mtx_unlock(&bounce_lock);
977 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
978 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
979 map->callback, map->callback_arg, /*flags*/0);
980 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
981 mtx_lock(&bounce_lock);
983 mtx_unlock(&bounce_lock);