2 * Copyright (c) 1997, 1998 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
26 * $FreeBSD: src/sys/i386/i386/busdma_machdep.c,v 1.94 2008/08/15 20:51:31 kmacy Exp $
27 * $DragonFly: src/sys/platform/pc32/i386/busdma_machdep.c,v 1.23 2008/06/05 18:06:32 swildner Exp $
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
35 #include <sys/bus_dma.h>
36 #include <sys/kernel.h>
37 #include <sys/sysctl.h>
40 #include <sys/thread2.h>
41 #include <sys/spinlock2.h>
42 #include <sys/mplock2.h>
45 #include <vm/vm_page.h>
47 /* XXX needed for to access pmap to convert per-proc virtual to physical */
50 #include <vm/vm_map.h>
52 #include <machine/md_var.h>
54 #define MAX_BPAGES 1024
65 bus_dma_filter_t *filter;
73 bus_dma_segment_t *segments;
74 struct bounce_zone *bounce_zone;
78 * bus_dma_tag private flags
80 #define BUS_DMA_BOUNCE_ALIGN BUS_DMA_BUS2
81 #define BUS_DMA_BOUNCE_LOWADDR BUS_DMA_BUS3
82 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
84 #define BUS_DMA_COULD_BOUNCE (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
86 #define BUS_DMAMEM_KMALLOC(dmat) \
87 ((dmat)->maxsize <= PAGE_SIZE && \
88 (dmat)->alignment <= PAGE_SIZE && \
89 (dmat)->lowaddr >= ptoa(Maxmem))
92 vm_offset_t vaddr; /* kva of bounce buffer */
93 bus_addr_t busaddr; /* Physical address */
94 vm_offset_t datavaddr; /* kva of client data */
95 bus_size_t datacount; /* client data count */
96 STAILQ_ENTRY(bounce_page) links;
100 STAILQ_ENTRY(bounce_zone) links;
101 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
102 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
104 struct spinlock spin;
115 bus_size_t alignment;
119 struct sysctl_ctx_list sysctl_ctx;
120 struct sysctl_oid *sysctl_tree;
124 #define BZ_LOCK(bz) spin_lock(&(bz)->spin)
125 #define BZ_UNLOCK(bz) spin_unlock(&(bz)->spin)
127 #define BZ_LOCK(bz) crit_enter()
128 #define BZ_UNLOCK(bz) crit_exit()
131 static struct lwkt_token bounce_zone_tok =
132 LWKT_TOKEN_MP_INITIALIZER(bounce_zone_token);
133 static int busdma_zonecount;
134 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
135 STAILQ_HEAD_INITIALIZER(bounce_zone_list);
137 int busdma_swi_pending;
138 static int total_bounce_pages;
139 static int max_bounce_pages = MAX_BPAGES;
140 static int bounce_alignment = 1; /* XXX temporary */
142 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
143 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
146 struct bp_list bpages;
150 void *buf; /* unmapped buffer pointer */
151 bus_size_t buflen; /* unmapped buffer length */
152 bus_dmamap_callback_t *callback;
154 STAILQ_ENTRY(bus_dmamap) links;
157 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
158 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
160 static struct bus_dmamap nobounce_dmamap;
162 static int alloc_bounce_zone(bus_dma_tag_t);
163 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int);
164 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
165 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
166 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
167 vm_offset_t, bus_size_t);
168 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
170 static bus_dmamap_t get_map_waiting(bus_dma_tag_t);
171 static void add_map_callback(bus_dmamap_t);
173 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
174 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
175 0, "Total bounce pages");
176 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
177 0, "Max bounce pages per bounce zone");
178 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
179 &bounce_alignment, 0, "Obey alignment constraint");
182 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
188 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
189 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
190 && (dmat->filter == NULL ||
191 dmat->filter(dmat->filterarg, paddr) != 0))
195 } while (retval == 0 && dmat != NULL);
200 * Allocate a device specific dma_tag.
203 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
204 bus_size_t boundary, bus_addr_t lowaddr,
205 bus_addr_t highaddr, bus_dma_filter_t *filter,
206 void *filterarg, bus_size_t maxsize, int nsegments,
207 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
209 bus_dma_tag_t newtag;
218 if (alignment & (alignment - 1))
219 panic("alignment must be power of 2\n");
222 if (boundary & (boundary - 1))
223 panic("boundary must be power of 2\n");
224 if (boundary < maxsegsz) {
225 kprintf("boundary < maxsegsz:\n");
231 /* Return a NULL tag on failure */
234 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
236 newtag->parent = parent;
237 newtag->alignment = alignment;
238 newtag->boundary = boundary;
239 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
240 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
241 newtag->filter = filter;
242 newtag->filterarg = filterarg;
243 newtag->maxsize = maxsize;
244 newtag->nsegments = nsegments;
245 newtag->maxsegsz = maxsegsz;
246 newtag->flags = flags;
247 newtag->ref_count = 1; /* Count ourself */
248 newtag->map_count = 0;
249 newtag->segments = NULL;
250 newtag->bounce_zone = NULL;
252 /* Take into account any restrictions imposed by our parent tag */
253 if (parent != NULL) {
254 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
255 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
257 if (newtag->boundary == 0) {
258 newtag->boundary = parent->boundary;
259 } else if (parent->boundary != 0) {
260 newtag->boundary = MIN(parent->boundary,
265 newtag->alignment = MAX(parent->alignment, newtag->alignment);
268 if (newtag->filter == NULL) {
270 * Short circuit looking at our parent directly
271 * since we have encapsulated all of its information
273 newtag->filter = parent->filter;
274 newtag->filterarg = parent->filterarg;
275 newtag->parent = parent->parent;
277 if (newtag->parent != NULL)
281 if (newtag->lowaddr < ptoa(Maxmem))
282 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
283 if (bounce_alignment && newtag->alignment > 1 &&
284 !(newtag->flags & BUS_DMA_ALIGNED))
285 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
287 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
288 (flags & BUS_DMA_ALLOCNOW) != 0) {
289 struct bounce_zone *bz;
293 error = alloc_bounce_zone(newtag);
296 bz = newtag->bounce_zone;
298 if (ptoa(bz->total_bpages) < maxsize) {
301 if (flags & BUS_DMA_ONEBPAGE) {
304 pages = atop(round_page(maxsize)) -
306 pages = MAX(pages, 1);
309 /* Add pages to our bounce pool */
310 if (alloc_bounce_pages(newtag, pages, flags) < pages)
313 /* Performed initial allocation */
314 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
319 kfree(newtag, M_DEVBUF);
326 bus_dma_tag_destroy(bus_dma_tag_t dmat)
329 if (dmat->map_count != 0)
332 while (dmat != NULL) {
333 bus_dma_tag_t parent;
335 parent = dmat->parent;
337 if (dmat->ref_count == 0) {
338 if (dmat->segments != NULL)
339 kfree(dmat->segments, M_DEVBUF);
340 kfree(dmat, M_DEVBUF);
342 * Last reference count, so
343 * release our reference
344 * count on our parent.
355 * Allocate a handle for mapping from kva/uva/physical
356 * address space into bus device space.
359 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
365 if (dmat->segments == NULL) {
366 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
367 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
368 dmat->nsegments, M_DEVBUF, M_INTWAIT);
371 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
372 struct bounce_zone *bz;
377 if (dmat->bounce_zone == NULL) {
378 error = alloc_bounce_zone(dmat);
382 bz = dmat->bounce_zone;
384 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
386 /* Initialize the new map */
387 STAILQ_INIT(&((*mapp)->bpages));
390 * Attempt to add pages to our pool on a per-instance
391 * basis up to a sane limit.
393 if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
394 maxpages = max_bounce_pages;
396 maxpages = MIN(max_bounce_pages,
397 Maxmem - atop(dmat->lowaddr));
399 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
400 || (dmat->map_count > 0
401 && bz->total_bpages < maxpages)) {
404 if (flags & BUS_DMA_ONEBPAGE) {
407 pages = atop(round_page(dmat->maxsize));
408 pages = MIN(maxpages - bz->total_bpages, pages);
409 pages = MAX(pages, 1);
411 if (alloc_bounce_pages(dmat, pages, flags) < pages)
414 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
416 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
430 * Destroy a handle for mapping from kva/uva/physical
431 * address space into bus device space.
434 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
437 if (STAILQ_FIRST(&map->bpages) != NULL)
439 kfree(map, M_DEVBUF);
445 static __inline bus_size_t
446 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
448 bus_size_t maxsize = 0;
449 uintptr_t vaddr = (uintptr_t)vaddr0;
451 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
452 if (verify || bootverbose)
453 kprintf("boundary check failed\n");
455 print_backtrace(-1); /* XXX panic */
456 maxsize = dmat->maxsize;
458 if (vaddr & (dmat->alignment - 1)) {
459 if (verify || bootverbose)
460 kprintf("alignment check failed\n");
462 print_backtrace(-1); /* XXX panic */
463 if (dmat->maxsize < dmat->alignment)
464 maxsize = dmat->alignment;
466 maxsize = dmat->maxsize;
472 * Allocate a piece of memory that can be efficiently mapped into
473 * bus device space based on the constraints lited in the dma tag.
475 * mapp is degenerate. By definition this allocation should not require
476 * bounce buffers so do not allocate a dma map.
479 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
484 /* If we succeed, no mapping/bouncing will be required */
487 if (dmat->segments == NULL) {
488 KKASSERT(dmat->nsegments < 16384);
489 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
490 dmat->nsegments, M_DEVBUF, M_INTWAIT);
493 if (flags & BUS_DMA_NOWAIT)
497 if (flags & BUS_DMA_ZERO)
500 if (BUS_DMAMEM_KMALLOC(dmat)) {
503 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
507 * Check whether the allocation
508 * - crossed a page boundary
510 * Retry with power-of-2 alignment in the above cases.
512 maxsize = check_kmalloc(dmat, *vaddr, 0);
516 kfree(*vaddr, M_DEVBUF);
517 /* XXX check for overflow? */
518 for (size = 1; size <= maxsize; size <<= 1)
520 *vaddr = kmalloc(size, M_DEVBUF, mflags);
521 check_kmalloc(dmat, *vaddr, 1);
525 * XXX Use Contigmalloc until it is merged into this facility
526 * and handles multi-seg allocations. Nobody is doing
527 * multi-seg allocations yet though.
529 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
530 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
538 * Free a piece of memory and it's allociated dmamap, that was allocated
539 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
542 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
545 * dmamem does not need to be bounced, so the map should be
549 panic("bus_dmamem_free: Invalid map freed\n");
550 if (BUS_DMAMEM_KMALLOC(dmat))
551 kfree(vaddr, M_DEVBUF);
553 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
556 static __inline vm_paddr_t
557 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
560 return pmap_extract(pmap, vaddr);
562 return pmap_kextract(vaddr);
566 * Utility function to load a linear buffer. lastaddrp holds state
567 * between invocations (for multiple-buffer loads). segp contains
568 * the segment following the starting one on entrace, and the ending
569 * segment on exit. first indicates if this is the first invocation
573 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
575 void *buf, bus_size_t buflen,
576 bus_dma_segment_t *segments,
580 vm_paddr_t *lastpaddrp,
585 vm_paddr_t paddr, nextpaddr;
586 bus_dma_segment_t *sg;
591 map = &nobounce_dmamap;
594 if (dmat->flags & BUS_DMA_ALIGNED)
595 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
599 * If we are being called during a callback, pagesneeded will
600 * be non-zero, so we can avoid doing the work twice.
602 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
603 map != &nobounce_dmamap && map->pagesneeded == 0) {
604 vm_offset_t vendaddr;
607 * Count the number of bounce pages
608 * needed in order to complete this transfer
610 vaddr = (vm_offset_t)buf;
611 vendaddr = (vm_offset_t)buf + buflen;
613 while (vaddr < vendaddr) {
614 paddr = _bus_dma_extract(pmap, vaddr);
615 if (run_filter(dmat, paddr) != 0)
617 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
621 /* Reserve Necessary Bounce Pages */
622 if (map->pagesneeded != 0) {
623 struct bounce_zone *bz;
625 bz = dmat->bounce_zone;
627 if (flags & BUS_DMA_NOWAIT) {
628 if (reserve_bounce_pages(dmat, map, 0) != 0) {
634 if (reserve_bounce_pages(dmat, map, 1) != 0) {
635 /* Queue us for resources */
638 map->buflen = buflen;
641 &dmat->bounce_zone->bounce_map_waitinglist,
645 return (EINPROGRESS);
651 KKASSERT(*segp >= 1 && *segp <= nsegments);
653 sg = &segments[seg - 1];
655 vaddr = (vm_offset_t)buf;
656 nextpaddr = *lastpaddrp;
657 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
659 /* force at least one segment */
666 paddr = _bus_dma_extract(pmap, vaddr);
667 size = PAGE_SIZE - (paddr & PAGE_MASK);
670 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
672 * note: this paddr has the same in-page offset
673 * as vaddr and thus the paddr above, so the
674 * size does not have to be recalculated
676 paddr = add_bounce_page(dmat, map, vaddr, size);
680 * Fill in the bus_dma_segment
686 } else if (paddr == nextpaddr) {
696 nextpaddr = paddr + size;
699 * Handle maxsegsz and boundary issues with a nested loop
705 * Limit to the boundary and maximum segment size
707 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
708 tmpsize = dmat->boundary -
709 (sg->ds_addr & ~bmask);
710 if (tmpsize > dmat->maxsegsz)
711 tmpsize = dmat->maxsegsz;
712 KKASSERT(tmpsize < sg->ds_len);
713 } else if (sg->ds_len > dmat->maxsegsz) {
714 tmpsize = dmat->maxsegsz;
720 * Futz, split the data into a new segment.
722 if (seg >= nsegments)
724 sg[1].ds_len = sg[0].ds_len - tmpsize;
725 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
726 sg[0].ds_len = tmpsize;
736 } while (buflen > 0);
742 *lastpaddrp = nextpaddr;
745 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
746 map != &nobounce_dmamap) {
747 _bus_dmamap_unload(dmat, map);
748 return_bounce_pages(dmat, map);
754 * Map the buffer buf into bus space using the dmamap map.
757 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
758 bus_size_t buflen, bus_dmamap_callback_t *callback,
759 void *callback_arg, int flags)
761 vm_paddr_t lastaddr = 0;
762 int error, nsegs = 1;
767 * Follow old semantics. Once all of the callers are fixed,
768 * we should get rid of these internal flag "adjustment".
770 flags &= ~BUS_DMA_NOWAIT;
771 flags |= BUS_DMA_WAITOK;
773 map->callback = callback;
774 map->callback_arg = callback_arg;
777 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
778 dmat->segments, dmat->nsegments,
779 NULL, flags, &lastaddr, &nsegs, 1);
780 if (error == EINPROGRESS)
783 callback(callback_arg, dmat->segments, nsegs, error);
788 * Like _bus_dmamap_load(), but for mbufs.
791 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
793 bus_dmamap_callback2_t *callback, void *callback_arg,
800 * Follow old semantics. Once all of the callers are fixed,
801 * we should get rid of these internal flag "adjustment".
803 flags &= ~BUS_DMA_WAITOK;
804 flags |= BUS_DMA_NOWAIT;
806 error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
807 dmat->segments, dmat->nsegments, &nsegs, flags);
809 /* force "no valid mappings" in callback */
810 callback(callback_arg, dmat->segments, 0, 0, error);
812 callback(callback_arg, dmat->segments, nsegs,
813 m0->m_pkthdr.len, error);
819 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
821 bus_dma_segment_t *segs, int maxsegs,
822 int *nsegs, int flags)
828 KASSERT(maxsegs >= 1, ("invalid maxsegs %d\n", maxsegs));
829 KASSERT(maxsegs <= dmat->nsegments,
830 ("%d too many segments, dmat only support %d segments\n",
831 maxsegs, dmat->nsegments));
832 KASSERT(flags & BUS_DMA_NOWAIT,
833 ("only BUS_DMA_NOWAIT is supported\n"));
835 if (m0->m_pkthdr.len <= dmat->maxsize) {
837 vm_paddr_t lastaddr = 0;
842 for (m = m0; m != NULL && error == 0; m = m->m_next) {
846 error = _bus_dmamap_load_buffer(dmat, map,
849 NULL, flags, &lastaddr,
851 if (error == ENOMEM && !first) {
853 * Out of bounce pages due to too many
854 * fragments in the mbuf chain; return
863 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
869 KKASSERT(error != EINPROGRESS);
874 * Like _bus_dmamap_load(), but for uios.
877 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
879 bus_dmamap_callback2_t *callback, void *callback_arg,
883 int nsegs, error, first, i;
890 * Follow old semantics. Once all of the callers are fixed,
891 * we should get rid of these internal flag "adjustment".
893 flags &= ~BUS_DMA_WAITOK;
894 flags |= BUS_DMA_NOWAIT;
896 resid = (bus_size_t)uio->uio_resid;
899 if (uio->uio_segflg == UIO_USERSPACE) {
903 KASSERT(td != NULL && td->td_proc != NULL,
904 ("bus_dmamap_load_uio: USERSPACE but no proc"));
905 pmap = vmspace_pmap(td->td_proc->p_vmspace);
914 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
916 * Now at the first iovec to load. Load each iovec
917 * until we have exhausted the residual count.
920 resid < iov[i].iov_len ? resid : iov[i].iov_len;
921 caddr_t addr = (caddr_t) iov[i].iov_base;
923 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
924 dmat->segments, dmat->nsegments,
925 pmap, flags, &lastaddr, &nsegs, first);
932 /* force "no valid mappings" in callback */
933 callback(callback_arg, dmat->segments, 0, 0, error);
935 callback(callback_arg, dmat->segments, nsegs,
936 (bus_size_t)uio->uio_resid, error);
942 * Release the mapping held by map.
945 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
947 struct bounce_page *bpage;
949 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
950 STAILQ_REMOVE_HEAD(&map->bpages, links);
951 free_bounce_page(dmat, bpage);
956 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
958 struct bounce_page *bpage;
960 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
962 * Handle data bouncing. We might also
963 * want to add support for invalidating
964 * the caches on broken hardware
967 case BUS_DMASYNC_PREWRITE:
968 while (bpage != NULL) {
969 bcopy((void *)bpage->datavaddr,
970 (void *)bpage->vaddr,
972 bpage = STAILQ_NEXT(bpage, links);
974 dmat->bounce_zone->total_bounced++;
977 case BUS_DMASYNC_POSTREAD:
978 while (bpage != NULL) {
979 bcopy((void *)bpage->vaddr,
980 (void *)bpage->datavaddr,
982 bpage = STAILQ_NEXT(bpage, links);
984 dmat->bounce_zone->total_bounced++;
987 case BUS_DMASYNC_PREREAD:
988 case BUS_DMASYNC_POSTWRITE:
996 alloc_bounce_zone(bus_dma_tag_t dmat)
998 struct bounce_zone *bz, *new_bz;
1000 KASSERT(dmat->bounce_zone == NULL,
1001 ("bounce zone was already assigned\n"));
1003 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1005 lwkt_gettoken(&bounce_zone_tok);
1007 /* Check to see if we already have a suitable zone */
1008 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1009 if (dmat->alignment <= bz->alignment &&
1010 dmat->lowaddr >= bz->lowaddr) {
1011 lwkt_reltoken(&bounce_zone_tok);
1013 dmat->bounce_zone = bz;
1014 kfree(new_bz, M_DEVBUF);
1021 spin_init(&bz->spin);
1023 STAILQ_INIT(&bz->bounce_page_list);
1024 STAILQ_INIT(&bz->bounce_map_waitinglist);
1025 bz->free_bpages = 0;
1026 bz->reserved_bpages = 0;
1027 bz->active_bpages = 0;
1028 bz->lowaddr = dmat->lowaddr;
1029 bz->alignment = round_page(dmat->alignment);
1030 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1032 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1033 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1035 lwkt_reltoken(&bounce_zone_tok);
1037 dmat->bounce_zone = bz;
1039 sysctl_ctx_init(&bz->sysctl_ctx);
1040 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1041 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1043 if (bz->sysctl_tree == NULL) {
1044 sysctl_ctx_free(&bz->sysctl_ctx);
1045 return 0; /* XXX error code? */
1048 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1049 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1050 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1051 "Total bounce pages");
1052 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1053 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1054 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1055 "Free bounce pages");
1056 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1057 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1058 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1059 "Reserved bounce pages");
1060 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1061 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1062 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1063 "Active bounce pages");
1064 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1065 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1066 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1067 "Total bounce requests");
1068 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1069 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1070 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1071 "Total bounce requests that were deferred");
1072 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1073 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1074 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1075 "Total bounce page reservations that were failed");
1076 SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1077 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1078 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1079 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1080 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1081 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1087 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1089 struct bounce_zone *bz = dmat->bounce_zone;
1090 int count = 0, mflags;
1092 if (flags & BUS_DMA_NOWAIT)
1097 while (numpages > 0) {
1098 struct bounce_page *bpage;
1100 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1102 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1106 if (bpage->vaddr == 0) {
1107 kfree(bpage, M_DEVBUF);
1110 bpage->busaddr = pmap_kextract(bpage->vaddr);
1113 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1114 total_bounce_pages++;
1125 /* Assume caller holds bounce zone spinlock */
1127 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1129 struct bounce_zone *bz = dmat->bounce_zone;
1132 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1133 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1134 bz->reserve_failed++;
1135 return (map->pagesneeded - (map->pagesreserved + pages));
1138 bz->free_bpages -= pages;
1140 bz->reserved_bpages += pages;
1141 KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1143 map->pagesreserved += pages;
1144 pages = map->pagesneeded - map->pagesreserved;
1150 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1152 struct bounce_zone *bz = dmat->bounce_zone;
1153 int reserved = map->pagesreserved;
1154 bus_dmamap_t wait_map;
1156 map->pagesreserved = 0;
1157 map->pagesneeded = 0;
1164 bz->free_bpages += reserved;
1165 KKASSERT(bz->free_bpages <= bz->total_bpages);
1167 KKASSERT(bz->reserved_bpages >= reserved);
1168 bz->reserved_bpages -= reserved;
1170 wait_map = get_map_waiting(dmat);
1174 if (wait_map != NULL)
1175 add_map_callback(map);
1179 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1182 struct bounce_zone *bz = dmat->bounce_zone;
1183 struct bounce_page *bpage;
1185 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1188 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1189 map->pagesreserved--;
1193 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1194 KASSERT(bpage != NULL, ("free page list is empty"));
1195 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1197 KKASSERT(bz->reserved_bpages > 0);
1198 bz->reserved_bpages--;
1200 bz->active_bpages++;
1201 KKASSERT(bz->active_bpages <= bz->total_bpages);
1205 bpage->datavaddr = vaddr;
1206 bpage->datacount = size;
1207 STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1208 return bpage->busaddr;
1212 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1214 struct bounce_zone *bz = dmat->bounce_zone;
1217 bpage->datavaddr = 0;
1218 bpage->datacount = 0;
1222 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1225 KKASSERT(bz->free_bpages <= bz->total_bpages);
1227 KKASSERT(bz->active_bpages > 0);
1228 bz->active_bpages--;
1230 map = get_map_waiting(dmat);
1235 add_map_callback(map);
1238 /* Assume caller holds bounce zone spinlock */
1240 get_map_waiting(bus_dma_tag_t dmat)
1242 struct bounce_zone *bz = dmat->bounce_zone;
1245 map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1247 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1248 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1249 bz->total_deferred++;
1258 add_map_callback(bus_dmamap_t map)
1261 /* XXX callbacklist is not MPSAFE */
1264 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1265 busdma_swi_pending = 1;
1270 panic("%s uncoded\n", __func__);
1281 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1282 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1284 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1285 map->callback, map->callback_arg, /*flags*/0);