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 $
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/malloc.h>
34 #include <sys/thread2.h>
35 #include <sys/bus_dma.h>
36 #include <sys/kernel.h>
37 #include <sys/sysctl.h>
39 #include <sys/spinlock2.h>
42 #include <vm/vm_page.h>
44 /* XXX needed for to access pmap to convert per-proc virtual to physical */
46 #include <vm/vm_map.h>
48 #include <machine/md_var.h>
50 #define MAX_BPAGES 1024
61 bus_dma_filter_t *filter;
69 bus_dma_segment_t *segments;
70 struct bounce_zone *bounce_zone;
74 * bus_dma_tag private flags
76 #define BUS_DMA_BOUNCE_ALIGN BUS_DMA_BUS2
77 #define BUS_DMA_BOUNCE_LOWADDR BUS_DMA_BUS3
78 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
80 #define BUS_DMA_COULD_BOUNCE (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
82 #define BUS_DMAMEM_KMALLOC(dmat) \
83 ((dmat)->maxsize <= PAGE_SIZE && \
84 (dmat)->alignment <= PAGE_SIZE && \
85 (dmat)->lowaddr >= ptoa(Maxmem))
88 vm_offset_t vaddr; /* kva of bounce buffer */
89 bus_addr_t busaddr; /* Physical address */
90 vm_offset_t datavaddr; /* kva of client data */
91 bus_size_t datacount; /* client data count */
92 STAILQ_ENTRY(bounce_page) links;
96 STAILQ_ENTRY(bounce_zone) links;
97 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
98 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
107 bus_size_t alignment;
111 struct sysctl_ctx_list sysctl_ctx;
112 struct sysctl_oid *sysctl_tree;
115 #define BZ_LOCK(bz) spin_lock(&(bz)->spin)
116 #define BZ_UNLOCK(bz) spin_unlock(&(bz)->spin)
118 static struct lwkt_token bounce_zone_tok =
119 LWKT_TOKEN_INITIALIZER(bounce_zone_token);
120 static int busdma_zonecount;
121 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
122 STAILQ_HEAD_INITIALIZER(bounce_zone_list);
124 int busdma_swi_pending;
125 static int total_bounce_pages;
126 static int max_bounce_pages = MAX_BPAGES;
127 static int bounce_alignment = 1; /* XXX temporary */
129 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
130 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
133 struct bp_list bpages;
137 void *buf; /* unmapped buffer pointer */
138 bus_size_t buflen; /* unmapped buffer length */
139 bus_dmamap_callback_t *callback;
141 STAILQ_ENTRY(bus_dmamap) links;
144 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
145 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
147 static struct bus_dmamap nobounce_dmamap;
149 static int alloc_bounce_zone(bus_dma_tag_t);
150 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int);
151 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
152 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
153 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
154 vm_offset_t, bus_size_t);
155 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
157 static bus_dmamap_t get_map_waiting(bus_dma_tag_t);
158 static void add_map_callback(bus_dmamap_t);
160 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
161 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
162 0, "Total bounce pages");
163 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
164 0, "Max bounce pages per bounce zone");
165 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
166 &bounce_alignment, 0, "Obey alignment constraint");
169 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
175 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
176 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
177 && (dmat->filter == NULL ||
178 dmat->filter(dmat->filterarg, paddr) != 0))
182 } while (retval == 0 && dmat != NULL);
187 * Allocate a device specific dma_tag.
190 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
191 bus_size_t boundary, bus_addr_t lowaddr,
192 bus_addr_t highaddr, bus_dma_filter_t *filter,
193 void *filterarg, bus_size_t maxsize, int nsegments,
194 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
196 bus_dma_tag_t newtag;
205 if (alignment & (alignment - 1))
206 panic("alignment must be power of 2");
209 if (boundary & (boundary - 1))
210 panic("boundary must be power of 2");
211 if (boundary < maxsegsz) {
212 kprintf("boundary < maxsegsz:\n");
218 /* Return a NULL tag on failure */
221 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
223 newtag->parent = parent;
224 newtag->alignment = alignment;
225 newtag->boundary = boundary;
226 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
227 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
228 newtag->filter = filter;
229 newtag->filterarg = filterarg;
230 newtag->maxsize = maxsize;
231 newtag->nsegments = nsegments;
232 newtag->maxsegsz = maxsegsz;
233 newtag->flags = flags;
234 newtag->ref_count = 1; /* Count ourself */
235 newtag->map_count = 0;
236 newtag->segments = NULL;
237 newtag->bounce_zone = NULL;
239 /* Take into account any restrictions imposed by our parent tag */
240 if (parent != NULL) {
241 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
242 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
244 if (newtag->boundary == 0) {
245 newtag->boundary = parent->boundary;
246 } else if (parent->boundary != 0) {
247 newtag->boundary = MIN(parent->boundary,
252 newtag->alignment = MAX(parent->alignment, newtag->alignment);
255 if (newtag->filter == NULL) {
257 * Short circuit looking at our parent directly
258 * since we have encapsulated all of its information
260 newtag->filter = parent->filter;
261 newtag->filterarg = parent->filterarg;
262 newtag->parent = parent->parent;
264 if (newtag->parent != NULL)
268 if (newtag->lowaddr < ptoa(Maxmem))
269 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
270 if (bounce_alignment && newtag->alignment > 1 &&
271 !(newtag->flags & BUS_DMA_ALIGNED))
272 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
274 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
275 (flags & BUS_DMA_ALLOCNOW) != 0) {
276 struct bounce_zone *bz;
280 error = alloc_bounce_zone(newtag);
283 bz = newtag->bounce_zone;
285 if (ptoa(bz->total_bpages) < maxsize) {
288 if (flags & BUS_DMA_ONEBPAGE) {
291 pages = atop(round_page(maxsize)) -
293 pages = MAX(pages, 1);
296 /* Add pages to our bounce pool */
297 if (alloc_bounce_pages(newtag, pages, flags) < pages)
300 /* Performed initial allocation */
301 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
306 kfree(newtag, M_DEVBUF);
313 bus_dma_tag_destroy(bus_dma_tag_t dmat)
316 if (dmat->map_count != 0)
319 while (dmat != NULL) {
320 bus_dma_tag_t parent;
322 parent = dmat->parent;
324 if (dmat->ref_count == 0) {
325 if (dmat->segments != NULL)
326 kfree(dmat->segments, M_DEVBUF);
327 kfree(dmat, M_DEVBUF);
329 * Last reference count, so
330 * release our reference
331 * count on our parent.
342 * Allocate a handle for mapping from kva/uva/physical
343 * address space into bus device space.
346 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
352 if (dmat->segments == NULL) {
353 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
354 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
355 dmat->nsegments, M_DEVBUF, M_INTWAIT);
358 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
359 struct bounce_zone *bz;
364 if (dmat->bounce_zone == NULL) {
365 error = alloc_bounce_zone(dmat);
369 bz = dmat->bounce_zone;
371 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
373 /* Initialize the new map */
374 STAILQ_INIT(&((*mapp)->bpages));
377 * Attempt to add pages to our pool on a per-instance
378 * basis up to a sane limit.
380 if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
381 maxpages = max_bounce_pages;
383 maxpages = MIN(max_bounce_pages,
384 Maxmem - atop(dmat->lowaddr));
386 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
387 || (dmat->map_count > 0
388 && bz->total_bpages < maxpages)) {
391 if (flags & BUS_DMA_ONEBPAGE) {
394 pages = atop(round_page(dmat->maxsize));
395 pages = MIN(maxpages - bz->total_bpages, pages);
396 pages = MAX(pages, 1);
398 if (alloc_bounce_pages(dmat, pages, flags) < pages)
401 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
403 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
417 * Destroy a handle for mapping from kva/uva/physical
418 * address space into bus device space.
421 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
424 if (STAILQ_FIRST(&map->bpages) != NULL)
426 kfree(map, M_DEVBUF);
432 static __inline bus_size_t
433 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
435 bus_size_t maxsize = 0;
436 uintptr_t vaddr = (uintptr_t)vaddr0;
438 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
439 kprintf("boundary check failed\n");
441 print_backtrace(-1); /* XXX panic */
442 maxsize = dmat->maxsize;
444 if (vaddr & (dmat->alignment - 1)) {
445 kprintf("alignment check failed\n");
447 print_backtrace(-1); /* XXX panic */
448 if (dmat->maxsize < dmat->alignment)
449 maxsize = dmat->alignment;
451 maxsize = dmat->maxsize;
457 * Allocate a piece of memory that can be efficiently mapped into
458 * bus device space based on the constraints lited in the dma tag.
460 * mapp is degenerate. By definition this allocation should not require
461 * bounce buffers so do not allocate a dma map.
464 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
469 /* If we succeed, no mapping/bouncing will be required */
472 if (dmat->segments == NULL) {
473 KKASSERT(dmat->nsegments < 16384);
474 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
475 dmat->nsegments, M_DEVBUF, M_INTWAIT);
478 if (flags & BUS_DMA_NOWAIT)
482 if (flags & BUS_DMA_ZERO)
485 if (BUS_DMAMEM_KMALLOC(dmat)) {
488 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
492 * Check whether the allocation
493 * - crossed a page boundary
495 * Retry with power-of-2 alignment in the above cases.
497 maxsize = check_kmalloc(dmat, *vaddr, 0);
501 kfree(*vaddr, M_DEVBUF);
502 /* XXX check for overflow? */
503 for (size = 1; size <= maxsize; size <<= 1)
505 *vaddr = kmalloc(size, M_DEVBUF, mflags);
506 check_kmalloc(dmat, *vaddr, 1);
510 * XXX Use Contigmalloc until it is merged into this facility
511 * and handles multi-seg allocations. Nobody is doing
512 * multi-seg allocations yet though.
514 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
515 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
523 * Free a piece of memory and it's allociated dmamap, that was allocated
524 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
527 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
530 * dmamem does not need to be bounced, so the map should be
534 panic("bus_dmamem_free: Invalid map freed");
535 if (BUS_DMAMEM_KMALLOC(dmat))
536 kfree(vaddr, M_DEVBUF);
538 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
541 static __inline vm_paddr_t
542 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
545 return pmap_extract(pmap, vaddr);
547 return pmap_kextract(vaddr);
551 * Utility function to load a linear buffer. lastaddrp holds state
552 * between invocations (for multiple-buffer loads). segp contains
553 * the segment following the starting one on entrace, and the ending
554 * segment on exit. first indicates if this is the first invocation
558 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
560 void *buf, bus_size_t buflen,
561 bus_dma_segment_t *segments,
565 vm_paddr_t *lastpaddrp,
570 vm_paddr_t paddr, nextpaddr;
571 bus_dma_segment_t *sg;
576 map = &nobounce_dmamap;
579 if (dmat->flags & BUS_DMA_ALIGNED)
580 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
584 * If we are being called during a callback, pagesneeded will
585 * be non-zero, so we can avoid doing the work twice.
587 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
588 map != &nobounce_dmamap && map->pagesneeded == 0) {
589 vm_offset_t vendaddr;
592 * Count the number of bounce pages
593 * needed in order to complete this transfer
595 vaddr = (vm_offset_t)buf;
596 vendaddr = (vm_offset_t)buf + buflen;
598 while (vaddr < vendaddr) {
599 paddr = _bus_dma_extract(pmap, vaddr);
600 if (run_filter(dmat, paddr) != 0)
602 vaddr += (PAGE_SIZE - (vaddr & PAGE_MASK));
606 /* Reserve Necessary Bounce Pages */
607 if (map->pagesneeded != 0) {
608 struct bounce_zone *bz;
610 bz = dmat->bounce_zone;
612 if (flags & BUS_DMA_NOWAIT) {
613 if (reserve_bounce_pages(dmat, map, 0) != 0) {
619 if (reserve_bounce_pages(dmat, map, 1) != 0) {
620 /* Queue us for resources */
623 map->buflen = buflen;
626 &dmat->bounce_zone->bounce_map_waitinglist,
630 return (EINPROGRESS);
636 KKASSERT(*segp >= 1 && *segp <= nsegments);
638 sg = &segments[seg - 1];
640 vaddr = (vm_offset_t)buf;
641 nextpaddr = *lastpaddrp;
642 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
644 /* force at least one segment */
651 paddr = _bus_dma_extract(pmap, vaddr);
652 size = PAGE_SIZE - (paddr & PAGE_MASK);
655 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
657 * note: this paddr has the same in-page offset
658 * as vaddr and thus the paddr above, so the
659 * size does not have to be recalculated
661 paddr = add_bounce_page(dmat, map, vaddr, size);
665 * Fill in the bus_dma_segment
671 } else if (paddr == nextpaddr) {
681 nextpaddr = paddr + size;
684 * Handle maxsegsz and boundary issues with a nested loop
690 * Limit to the boundary and maximum segment size
692 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
693 tmpsize = dmat->boundary -
694 (sg->ds_addr & ~bmask);
695 if (tmpsize > dmat->maxsegsz)
696 tmpsize = dmat->maxsegsz;
697 KKASSERT(tmpsize < sg->ds_len);
698 } else if (sg->ds_len > dmat->maxsegsz) {
699 tmpsize = dmat->maxsegsz;
705 * Futz, split the data into a new segment.
707 if (seg >= nsegments)
709 sg[1].ds_len = sg[0].ds_len - tmpsize;
710 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
711 sg[0].ds_len = tmpsize;
721 } while (buflen > 0);
727 *lastpaddrp = nextpaddr;
730 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
731 map != &nobounce_dmamap) {
732 _bus_dmamap_unload(dmat, map);
733 return_bounce_pages(dmat, map);
739 * Map the buffer buf into bus space using the dmamap map.
742 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
743 bus_size_t buflen, bus_dmamap_callback_t *callback,
744 void *callback_arg, int flags)
746 vm_paddr_t lastaddr = 0;
747 int error, nsegs = 1;
752 * Follow old semantics. Once all of the callers are fixed,
753 * we should get rid of these internal flag "adjustment".
755 flags &= ~BUS_DMA_NOWAIT;
756 flags |= BUS_DMA_WAITOK;
758 map->callback = callback;
759 map->callback_arg = callback_arg;
762 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
763 dmat->segments, dmat->nsegments,
764 NULL, flags, &lastaddr, &nsegs, 1);
765 if (error == EINPROGRESS)
768 callback(callback_arg, dmat->segments, nsegs, error);
773 * Like _bus_dmamap_load(), but for mbufs.
776 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
778 bus_dmamap_callback2_t *callback, void *callback_arg,
785 * Follow old semantics. Once all of the callers are fixed,
786 * we should get rid of these internal flag "adjustment".
788 flags &= ~BUS_DMA_WAITOK;
789 flags |= BUS_DMA_NOWAIT;
791 error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
792 dmat->segments, dmat->nsegments, &nsegs, flags);
794 /* force "no valid mappings" in callback */
795 callback(callback_arg, dmat->segments, 0, 0, error);
797 callback(callback_arg, dmat->segments, nsegs,
798 m0->m_pkthdr.len, error);
804 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
806 bus_dma_segment_t *segs, int maxsegs,
807 int *nsegs, int flags)
813 KASSERT(maxsegs >= 1, ("invalid maxsegs %d", maxsegs));
814 KASSERT(maxsegs <= dmat->nsegments,
815 ("%d too many segments, dmat only supports %d segments",
816 maxsegs, dmat->nsegments));
817 KASSERT(flags & BUS_DMA_NOWAIT,
818 ("only BUS_DMA_NOWAIT is supported"));
820 if (m0->m_pkthdr.len <= dmat->maxsize) {
822 vm_paddr_t lastaddr = 0;
827 for (m = m0; m != NULL && error == 0; m = m->m_next) {
831 error = _bus_dmamap_load_buffer(dmat, map,
834 NULL, flags, &lastaddr,
836 if (error == ENOMEM && !first) {
838 * Out of bounce pages due to too many
839 * fragments in the mbuf chain; return
848 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
854 KKASSERT(error != EINPROGRESS);
859 * Like _bus_dmamap_load(), but for uios.
862 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
864 bus_dmamap_callback2_t *callback, void *callback_arg,
868 int nsegs, error, first, i;
875 * Follow old semantics. Once all of the callers are fixed,
876 * we should get rid of these internal flag "adjustment".
878 flags &= ~BUS_DMA_WAITOK;
879 flags |= BUS_DMA_NOWAIT;
881 resid = (bus_size_t)uio->uio_resid;
884 if (uio->uio_segflg == UIO_USERSPACE) {
888 KASSERT(td != NULL && td->td_proc != NULL,
889 ("bus_dmamap_load_uio: USERSPACE but no proc"));
890 pmap = vmspace_pmap(td->td_proc->p_vmspace);
899 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
901 * Now at the first iovec to load. Load each iovec
902 * until we have exhausted the residual count.
905 resid < iov[i].iov_len ? resid : iov[i].iov_len;
906 caddr_t addr = (caddr_t) iov[i].iov_base;
908 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
909 dmat->segments, dmat->nsegments,
910 pmap, flags, &lastaddr, &nsegs, first);
917 /* force "no valid mappings" in callback */
918 callback(callback_arg, dmat->segments, 0, 0, error);
920 callback(callback_arg, dmat->segments, nsegs,
921 (bus_size_t)uio->uio_resid, error);
927 * Release the mapping held by map.
930 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
932 struct bounce_page *bpage;
934 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
935 STAILQ_REMOVE_HEAD(&map->bpages, links);
936 free_bounce_page(dmat, bpage);
941 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
943 struct bounce_page *bpage;
945 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
947 * Handle data bouncing. We might also
948 * want to add support for invalidating
949 * the caches on broken hardware
952 case BUS_DMASYNC_PREWRITE:
953 while (bpage != NULL) {
954 bcopy((void *)bpage->datavaddr,
955 (void *)bpage->vaddr,
957 bpage = STAILQ_NEXT(bpage, links);
959 dmat->bounce_zone->total_bounced++;
962 case BUS_DMASYNC_POSTREAD:
963 while (bpage != NULL) {
964 bcopy((void *)bpage->vaddr,
965 (void *)bpage->datavaddr,
967 bpage = STAILQ_NEXT(bpage, links);
969 dmat->bounce_zone->total_bounced++;
972 case BUS_DMASYNC_PREREAD:
973 case BUS_DMASYNC_POSTWRITE:
981 alloc_bounce_zone(bus_dma_tag_t dmat)
983 struct bounce_zone *bz, *new_bz;
985 KASSERT(dmat->bounce_zone == NULL,
986 ("bounce zone was already assigned"));
988 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
990 lwkt_gettoken(&bounce_zone_tok);
992 /* Check to see if we already have a suitable zone */
993 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
994 if (dmat->alignment <= bz->alignment &&
995 dmat->lowaddr >= bz->lowaddr) {
996 lwkt_reltoken(&bounce_zone_tok);
998 dmat->bounce_zone = bz;
999 kfree(new_bz, M_DEVBUF);
1005 spin_init(&bz->spin);
1006 STAILQ_INIT(&bz->bounce_page_list);
1007 STAILQ_INIT(&bz->bounce_map_waitinglist);
1008 bz->free_bpages = 0;
1009 bz->reserved_bpages = 0;
1010 bz->active_bpages = 0;
1011 bz->lowaddr = dmat->lowaddr;
1012 bz->alignment = round_page(dmat->alignment);
1013 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1015 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1016 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1018 lwkt_reltoken(&bounce_zone_tok);
1020 dmat->bounce_zone = bz;
1022 sysctl_ctx_init(&bz->sysctl_ctx);
1023 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1024 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1026 if (bz->sysctl_tree == NULL) {
1027 sysctl_ctx_free(&bz->sysctl_ctx);
1028 return 0; /* XXX error code? */
1031 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1032 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1033 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1034 "Total bounce pages");
1035 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1036 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1037 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1038 "Free bounce pages");
1039 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1040 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1041 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1042 "Reserved bounce pages");
1043 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1044 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1045 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1046 "Active bounce pages");
1047 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1048 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1049 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1050 "Total bounce requests");
1051 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1052 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1053 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1054 "Total bounce requests that were deferred");
1055 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1056 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1057 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1058 "Total bounce page reservations that were failed");
1059 SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1060 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1061 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1062 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1063 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1064 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1070 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1072 struct bounce_zone *bz = dmat->bounce_zone;
1073 int count = 0, mflags;
1075 if (flags & BUS_DMA_NOWAIT)
1080 while (numpages > 0) {
1081 struct bounce_page *bpage;
1083 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1085 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1089 if (bpage->vaddr == 0) {
1090 kfree(bpage, M_DEVBUF);
1093 bpage->busaddr = pmap_kextract(bpage->vaddr);
1096 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1097 total_bounce_pages++;
1108 /* Assume caller holds bounce zone spinlock */
1110 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1112 struct bounce_zone *bz = dmat->bounce_zone;
1115 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1116 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1117 bz->reserve_failed++;
1118 return (map->pagesneeded - (map->pagesreserved + pages));
1121 bz->free_bpages -= pages;
1123 bz->reserved_bpages += pages;
1124 KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1126 map->pagesreserved += pages;
1127 pages = map->pagesneeded - map->pagesreserved;
1133 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1135 struct bounce_zone *bz = dmat->bounce_zone;
1136 int reserved = map->pagesreserved;
1137 bus_dmamap_t wait_map;
1139 map->pagesreserved = 0;
1140 map->pagesneeded = 0;
1147 bz->free_bpages += reserved;
1148 KKASSERT(bz->free_bpages <= bz->total_bpages);
1150 KKASSERT(bz->reserved_bpages >= reserved);
1151 bz->reserved_bpages -= reserved;
1153 wait_map = get_map_waiting(dmat);
1157 if (wait_map != NULL)
1158 add_map_callback(map);
1162 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1165 struct bounce_zone *bz = dmat->bounce_zone;
1166 struct bounce_page *bpage;
1168 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1171 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1172 map->pagesreserved--;
1176 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1177 KASSERT(bpage != NULL, ("free page list is empty"));
1178 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1180 KKASSERT(bz->reserved_bpages > 0);
1181 bz->reserved_bpages--;
1183 bz->active_bpages++;
1184 KKASSERT(bz->active_bpages <= bz->total_bpages);
1188 bpage->datavaddr = vaddr;
1189 bpage->datacount = size;
1190 STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1191 return bpage->busaddr;
1195 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1197 struct bounce_zone *bz = dmat->bounce_zone;
1200 bpage->datavaddr = 0;
1201 bpage->datacount = 0;
1205 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1208 KKASSERT(bz->free_bpages <= bz->total_bpages);
1210 KKASSERT(bz->active_bpages > 0);
1211 bz->active_bpages--;
1213 map = get_map_waiting(dmat);
1218 add_map_callback(map);
1221 /* Assume caller holds bounce zone spinlock */
1223 get_map_waiting(bus_dma_tag_t dmat)
1225 struct bounce_zone *bz = dmat->bounce_zone;
1228 map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1230 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1231 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1232 bz->total_deferred++;
1241 add_map_callback(bus_dmamap_t map)
1244 /* XXX callbacklist is not MPSAFE */
1247 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1248 busdma_swi_pending = 1;
1253 panic("%s uncoded", __func__);
1264 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1265 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1267 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1268 map->callback, map->callback_arg, /*flags*/0);