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 */
47 #include <vm/vm_map.h>
49 #include <machine/md_var.h>
51 #define MAX_BPAGES 1024
62 bus_dma_filter_t *filter;
70 bus_dma_segment_t *segments;
71 struct bounce_zone *bounce_zone;
75 * bus_dma_tag private flags
77 #define BUS_DMA_BOUNCE_ALIGN BUS_DMA_BUS2
78 #define BUS_DMA_BOUNCE_LOWADDR BUS_DMA_BUS3
79 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
81 #define BUS_DMA_COULD_BOUNCE (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
83 #define BUS_DMAMEM_KMALLOC(dmat) \
84 ((dmat)->maxsize <= PAGE_SIZE && \
85 (dmat)->alignment <= PAGE_SIZE && \
86 (dmat)->lowaddr >= ptoa(Maxmem))
89 vm_offset_t vaddr; /* kva of bounce buffer */
90 bus_addr_t busaddr; /* Physical address */
91 vm_offset_t datavaddr; /* kva of client data */
92 bus_size_t datacount; /* client data count */
93 STAILQ_ENTRY(bounce_page) links;
97 STAILQ_ENTRY(bounce_zone) links;
98 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
99 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
100 struct spinlock spin;
108 bus_size_t alignment;
112 struct sysctl_ctx_list sysctl_ctx;
113 struct sysctl_oid *sysctl_tree;
116 #define BZ_LOCK(bz) spin_lock(&(bz)->spin)
117 #define BZ_UNLOCK(bz) spin_unlock(&(bz)->spin)
119 static struct lwkt_token bounce_zone_tok =
120 LWKT_TOKEN_INITIALIZER(bounce_zone_token);
121 static int busdma_zonecount;
122 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
123 STAILQ_HEAD_INITIALIZER(bounce_zone_list);
125 int busdma_swi_pending;
126 static int total_bounce_pages;
127 static int max_bounce_pages = MAX_BPAGES;
128 static int bounce_alignment = 1; /* XXX temporary */
130 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
131 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
134 struct bp_list bpages;
138 void *buf; /* unmapped buffer pointer */
139 bus_size_t buflen; /* unmapped buffer length */
140 bus_dmamap_callback_t *callback;
142 STAILQ_ENTRY(bus_dmamap) links;
145 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
146 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
148 static struct bus_dmamap nobounce_dmamap;
150 static int alloc_bounce_zone(bus_dma_tag_t);
151 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int);
152 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
153 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
154 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
155 vm_offset_t, bus_size_t);
156 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
158 static bus_dmamap_t get_map_waiting(bus_dma_tag_t);
159 static void add_map_callback(bus_dmamap_t);
161 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
162 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
163 0, "Total bounce pages");
164 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
165 0, "Max bounce pages per bounce zone");
166 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
167 &bounce_alignment, 0, "Obey alignment constraint");
170 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
176 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
177 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
178 && (dmat->filter == NULL ||
179 dmat->filter(dmat->filterarg, paddr) != 0))
183 } while (retval == 0 && dmat != NULL);
188 * Allocate a device specific dma_tag.
191 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
192 bus_size_t boundary, bus_addr_t lowaddr,
193 bus_addr_t highaddr, bus_dma_filter_t *filter,
194 void *filterarg, bus_size_t maxsize, int nsegments,
195 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
197 bus_dma_tag_t newtag;
206 if (alignment & (alignment - 1))
207 panic("alignment must be power of 2");
210 if (boundary & (boundary - 1))
211 panic("boundary must be power of 2");
212 if (boundary < maxsegsz) {
213 kprintf("boundary < maxsegsz:\n");
219 /* Return a NULL tag on failure */
222 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
224 newtag->parent = parent;
225 newtag->alignment = alignment;
226 newtag->boundary = boundary;
227 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
228 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
229 newtag->filter = filter;
230 newtag->filterarg = filterarg;
231 newtag->maxsize = maxsize;
232 newtag->nsegments = nsegments;
233 newtag->maxsegsz = maxsegsz;
234 newtag->flags = flags;
235 newtag->ref_count = 1; /* Count ourself */
236 newtag->map_count = 0;
237 newtag->segments = NULL;
238 newtag->bounce_zone = NULL;
240 /* Take into account any restrictions imposed by our parent tag */
241 if (parent != NULL) {
242 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
243 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
245 if (newtag->boundary == 0) {
246 newtag->boundary = parent->boundary;
247 } else if (parent->boundary != 0) {
248 newtag->boundary = MIN(parent->boundary,
253 newtag->alignment = MAX(parent->alignment, newtag->alignment);
256 if (newtag->filter == NULL) {
258 * Short circuit looking at our parent directly
259 * since we have encapsulated all of its information
261 newtag->filter = parent->filter;
262 newtag->filterarg = parent->filterarg;
263 newtag->parent = parent->parent;
265 if (newtag->parent != NULL)
269 if (newtag->lowaddr < ptoa(Maxmem))
270 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
271 if (bounce_alignment && newtag->alignment > 1 &&
272 !(newtag->flags & BUS_DMA_ALIGNED))
273 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
275 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
276 (flags & BUS_DMA_ALLOCNOW) != 0) {
277 struct bounce_zone *bz;
281 error = alloc_bounce_zone(newtag);
284 bz = newtag->bounce_zone;
286 if (ptoa(bz->total_bpages) < maxsize) {
289 if (flags & BUS_DMA_ONEBPAGE) {
292 pages = atop(round_page(maxsize)) -
294 pages = MAX(pages, 1);
297 /* Add pages to our bounce pool */
298 if (alloc_bounce_pages(newtag, pages, flags) < pages)
301 /* Performed initial allocation */
302 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
307 kfree(newtag, M_DEVBUF);
314 bus_dma_tag_destroy(bus_dma_tag_t dmat)
317 if (dmat->map_count != 0)
320 while (dmat != NULL) {
321 bus_dma_tag_t parent;
323 parent = dmat->parent;
325 if (dmat->ref_count == 0) {
326 if (dmat->segments != NULL)
327 kfree(dmat->segments, M_DEVBUF);
328 kfree(dmat, M_DEVBUF);
330 * Last reference count, so
331 * release our reference
332 * count on our parent.
343 * Allocate a handle for mapping from kva/uva/physical
344 * address space into bus device space.
347 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
353 if (dmat->segments == NULL) {
354 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
355 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
356 dmat->nsegments, M_DEVBUF, M_INTWAIT);
359 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
360 struct bounce_zone *bz;
365 if (dmat->bounce_zone == NULL) {
366 error = alloc_bounce_zone(dmat);
370 bz = dmat->bounce_zone;
372 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
374 /* Initialize the new map */
375 STAILQ_INIT(&((*mapp)->bpages));
378 * Attempt to add pages to our pool on a per-instance
379 * basis up to a sane limit.
381 if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
382 maxpages = max_bounce_pages;
384 maxpages = MIN(max_bounce_pages,
385 Maxmem - atop(dmat->lowaddr));
387 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
388 || (dmat->map_count > 0
389 && bz->total_bpages < maxpages)) {
392 if (flags & BUS_DMA_ONEBPAGE) {
395 pages = atop(round_page(dmat->maxsize));
396 pages = MIN(maxpages - bz->total_bpages, pages);
397 pages = MAX(pages, 1);
399 if (alloc_bounce_pages(dmat, pages, flags) < pages)
402 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
404 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
418 * Destroy a handle for mapping from kva/uva/physical
419 * address space into bus device space.
422 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
425 if (STAILQ_FIRST(&map->bpages) != NULL)
427 kfree(map, M_DEVBUF);
433 static __inline bus_size_t
434 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
436 bus_size_t maxsize = 0;
437 uintptr_t vaddr = (uintptr_t)vaddr0;
439 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
440 kprintf("boundary check failed\n");
442 print_backtrace(-1); /* XXX panic */
443 maxsize = dmat->maxsize;
445 if (vaddr & (dmat->alignment - 1)) {
446 kprintf("alignment check failed\n");
448 print_backtrace(-1); /* XXX panic */
449 if (dmat->maxsize < dmat->alignment)
450 maxsize = dmat->alignment;
452 maxsize = dmat->maxsize;
458 * Allocate a piece of memory that can be efficiently mapped into
459 * bus device space based on the constraints lited in the dma tag.
461 * mapp is degenerate. By definition this allocation should not require
462 * bounce buffers so do not allocate a dma map.
465 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
470 /* If we succeed, no mapping/bouncing will be required */
473 if (dmat->segments == NULL) {
474 KKASSERT(dmat->nsegments < 16384);
475 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
476 dmat->nsegments, M_DEVBUF, M_INTWAIT);
479 if (flags & BUS_DMA_NOWAIT)
483 if (flags & BUS_DMA_ZERO)
486 if (BUS_DMAMEM_KMALLOC(dmat)) {
489 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
493 * Check whether the allocation
494 * - crossed a page boundary
496 * Retry with power-of-2 alignment in the above cases.
498 maxsize = check_kmalloc(dmat, *vaddr, 0);
502 kfree(*vaddr, M_DEVBUF);
503 /* XXX check for overflow? */
504 for (size = 1; size <= maxsize; size <<= 1)
506 *vaddr = kmalloc(size, M_DEVBUF, mflags);
507 check_kmalloc(dmat, *vaddr, 1);
511 * XXX Use Contigmalloc until it is merged into this facility
512 * and handles multi-seg allocations. Nobody is doing
513 * multi-seg allocations yet though.
515 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
516 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
524 * Free a piece of memory and it's allociated dmamap, that was allocated
525 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
528 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
531 * dmamem does not need to be bounced, so the map should be
535 panic("bus_dmamem_free: Invalid map freed");
536 if (BUS_DMAMEM_KMALLOC(dmat))
537 kfree(vaddr, M_DEVBUF);
539 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
542 static __inline vm_paddr_t
543 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
546 return pmap_extract(pmap, vaddr);
548 return pmap_kextract(vaddr);
552 * Utility function to load a linear buffer. lastaddrp holds state
553 * between invocations (for multiple-buffer loads). segp contains
554 * the segment following the starting one on entrace, and the ending
555 * segment on exit. first indicates if this is the first invocation
559 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
561 void *buf, bus_size_t buflen,
562 bus_dma_segment_t *segments,
566 vm_paddr_t *lastpaddrp,
571 vm_paddr_t paddr, nextpaddr;
572 bus_dma_segment_t *sg;
577 map = &nobounce_dmamap;
580 if (dmat->flags & BUS_DMA_ALIGNED)
581 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
585 * If we are being called during a callback, pagesneeded will
586 * be non-zero, so we can avoid doing the work twice.
588 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
589 map != &nobounce_dmamap && map->pagesneeded == 0) {
590 vm_offset_t vendaddr;
593 * Count the number of bounce pages
594 * needed in order to complete this transfer
596 vaddr = (vm_offset_t)buf;
597 vendaddr = (vm_offset_t)buf + buflen;
599 while (vaddr < vendaddr) {
600 paddr = _bus_dma_extract(pmap, vaddr);
601 if (run_filter(dmat, paddr) != 0)
603 vaddr += (PAGE_SIZE - (vaddr & PAGE_MASK));
607 /* Reserve Necessary Bounce Pages */
608 if (map->pagesneeded != 0) {
609 struct bounce_zone *bz;
611 bz = dmat->bounce_zone;
613 if (flags & BUS_DMA_NOWAIT) {
614 if (reserve_bounce_pages(dmat, map, 0) != 0) {
620 if (reserve_bounce_pages(dmat, map, 1) != 0) {
621 /* Queue us for resources */
624 map->buflen = buflen;
627 &dmat->bounce_zone->bounce_map_waitinglist,
631 return (EINPROGRESS);
637 KKASSERT(*segp >= 1 && *segp <= nsegments);
639 sg = &segments[seg - 1];
641 vaddr = (vm_offset_t)buf;
642 nextpaddr = *lastpaddrp;
643 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
645 /* force at least one segment */
652 paddr = _bus_dma_extract(pmap, vaddr);
653 size = PAGE_SIZE - (paddr & PAGE_MASK);
656 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
658 * note: this paddr has the same in-page offset
659 * as vaddr and thus the paddr above, so the
660 * size does not have to be recalculated
662 paddr = add_bounce_page(dmat, map, vaddr, size);
666 * Fill in the bus_dma_segment
672 } else if (paddr == nextpaddr) {
682 nextpaddr = paddr + size;
685 * Handle maxsegsz and boundary issues with a nested loop
691 * Limit to the boundary and maximum segment size
693 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
694 tmpsize = dmat->boundary -
695 (sg->ds_addr & ~bmask);
696 if (tmpsize > dmat->maxsegsz)
697 tmpsize = dmat->maxsegsz;
698 KKASSERT(tmpsize < sg->ds_len);
699 } else if (sg->ds_len > dmat->maxsegsz) {
700 tmpsize = dmat->maxsegsz;
706 * Futz, split the data into a new segment.
708 if (seg >= nsegments)
710 sg[1].ds_len = sg[0].ds_len - tmpsize;
711 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
712 sg[0].ds_len = tmpsize;
722 } while (buflen > 0);
728 *lastpaddrp = nextpaddr;
731 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
732 map != &nobounce_dmamap) {
733 _bus_dmamap_unload(dmat, map);
734 return_bounce_pages(dmat, map);
740 * Map the buffer buf into bus space using the dmamap map.
743 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
744 bus_size_t buflen, bus_dmamap_callback_t *callback,
745 void *callback_arg, int flags)
747 vm_paddr_t lastaddr = 0;
748 int error, nsegs = 1;
753 * Follow old semantics. Once all of the callers are fixed,
754 * we should get rid of these internal flag "adjustment".
756 flags &= ~BUS_DMA_NOWAIT;
757 flags |= BUS_DMA_WAITOK;
759 map->callback = callback;
760 map->callback_arg = callback_arg;
763 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
764 dmat->segments, dmat->nsegments,
765 NULL, flags, &lastaddr, &nsegs, 1);
766 if (error == EINPROGRESS)
769 callback(callback_arg, dmat->segments, nsegs, error);
774 * Like _bus_dmamap_load(), but for mbufs.
777 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
779 bus_dmamap_callback2_t *callback, void *callback_arg,
786 * Follow old semantics. Once all of the callers are fixed,
787 * we should get rid of these internal flag "adjustment".
789 flags &= ~BUS_DMA_WAITOK;
790 flags |= BUS_DMA_NOWAIT;
792 error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
793 dmat->segments, dmat->nsegments, &nsegs, flags);
795 /* force "no valid mappings" in callback */
796 callback(callback_arg, dmat->segments, 0, 0, error);
798 callback(callback_arg, dmat->segments, nsegs,
799 m0->m_pkthdr.len, error);
805 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
807 bus_dma_segment_t *segs, int maxsegs,
808 int *nsegs, int flags)
814 KASSERT(maxsegs >= 1, ("invalid maxsegs %d", maxsegs));
815 KASSERT(maxsegs <= dmat->nsegments,
816 ("%d too many segments, dmat only supports %d segments",
817 maxsegs, dmat->nsegments));
818 KASSERT(flags & BUS_DMA_NOWAIT,
819 ("only BUS_DMA_NOWAIT is supported"));
821 if (m0->m_pkthdr.len <= dmat->maxsize) {
823 vm_paddr_t lastaddr = 0;
828 for (m = m0; m != NULL && error == 0; m = m->m_next) {
832 error = _bus_dmamap_load_buffer(dmat, map,
835 NULL, flags, &lastaddr,
837 if (error == ENOMEM && !first) {
839 * Out of bounce pages due to too many
840 * fragments in the mbuf chain; return
849 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
855 KKASSERT(error != EINPROGRESS);
860 * Like _bus_dmamap_load(), but for uios.
863 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
865 bus_dmamap_callback2_t *callback, void *callback_arg,
869 int nsegs, error, first, i;
876 * Follow old semantics. Once all of the callers are fixed,
877 * we should get rid of these internal flag "adjustment".
879 flags &= ~BUS_DMA_WAITOK;
880 flags |= BUS_DMA_NOWAIT;
882 resid = (bus_size_t)uio->uio_resid;
885 if (uio->uio_segflg == UIO_USERSPACE) {
889 KASSERT(td != NULL && td->td_proc != NULL,
890 ("bus_dmamap_load_uio: USERSPACE but no proc"));
891 pmap = vmspace_pmap(td->td_proc->p_vmspace);
900 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
902 * Now at the first iovec to load. Load each iovec
903 * until we have exhausted the residual count.
906 resid < iov[i].iov_len ? resid : iov[i].iov_len;
907 caddr_t addr = (caddr_t) iov[i].iov_base;
909 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
910 dmat->segments, dmat->nsegments,
911 pmap, flags, &lastaddr, &nsegs, first);
918 /* force "no valid mappings" in callback */
919 callback(callback_arg, dmat->segments, 0, 0, error);
921 callback(callback_arg, dmat->segments, nsegs,
922 (bus_size_t)uio->uio_resid, error);
928 * Release the mapping held by map.
931 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
933 struct bounce_page *bpage;
935 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
936 STAILQ_REMOVE_HEAD(&map->bpages, links);
937 free_bounce_page(dmat, bpage);
942 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
944 struct bounce_page *bpage;
946 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
948 * Handle data bouncing. We might also
949 * want to add support for invalidating
950 * the caches on broken hardware
953 case BUS_DMASYNC_PREWRITE:
954 while (bpage != NULL) {
955 bcopy((void *)bpage->datavaddr,
956 (void *)bpage->vaddr,
958 bpage = STAILQ_NEXT(bpage, links);
960 dmat->bounce_zone->total_bounced++;
963 case BUS_DMASYNC_POSTREAD:
964 while (bpage != NULL) {
965 bcopy((void *)bpage->vaddr,
966 (void *)bpage->datavaddr,
968 bpage = STAILQ_NEXT(bpage, links);
970 dmat->bounce_zone->total_bounced++;
973 case BUS_DMASYNC_PREREAD:
974 case BUS_DMASYNC_POSTWRITE:
982 alloc_bounce_zone(bus_dma_tag_t dmat)
984 struct bounce_zone *bz, *new_bz;
986 KASSERT(dmat->bounce_zone == NULL,
987 ("bounce zone was already assigned"));
989 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
991 lwkt_gettoken(&bounce_zone_tok);
993 /* Check to see if we already have a suitable zone */
994 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
995 if (dmat->alignment <= bz->alignment &&
996 dmat->lowaddr >= bz->lowaddr) {
997 lwkt_reltoken(&bounce_zone_tok);
999 dmat->bounce_zone = bz;
1000 kfree(new_bz, M_DEVBUF);
1006 spin_init(&bz->spin);
1007 STAILQ_INIT(&bz->bounce_page_list);
1008 STAILQ_INIT(&bz->bounce_map_waitinglist);
1009 bz->free_bpages = 0;
1010 bz->reserved_bpages = 0;
1011 bz->active_bpages = 0;
1012 bz->lowaddr = dmat->lowaddr;
1013 bz->alignment = round_page(dmat->alignment);
1014 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1016 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1017 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1019 lwkt_reltoken(&bounce_zone_tok);
1021 dmat->bounce_zone = bz;
1023 sysctl_ctx_init(&bz->sysctl_ctx);
1024 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1025 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1027 if (bz->sysctl_tree == NULL) {
1028 sysctl_ctx_free(&bz->sysctl_ctx);
1029 return 0; /* XXX error code? */
1032 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1033 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1034 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1035 "Total bounce pages");
1036 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1037 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1038 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1039 "Free bounce pages");
1040 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1041 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1042 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1043 "Reserved bounce pages");
1044 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1045 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1046 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1047 "Active bounce pages");
1048 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1049 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1050 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1051 "Total bounce requests");
1052 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1053 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1054 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1055 "Total bounce requests that were deferred");
1056 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1057 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1058 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1059 "Total bounce page reservations that were failed");
1060 SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1061 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1062 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1063 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1064 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1065 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1071 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1073 struct bounce_zone *bz = dmat->bounce_zone;
1074 int count = 0, mflags;
1076 if (flags & BUS_DMA_NOWAIT)
1081 while (numpages > 0) {
1082 struct bounce_page *bpage;
1084 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1086 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1090 if (bpage->vaddr == 0) {
1091 kfree(bpage, M_DEVBUF);
1094 bpage->busaddr = pmap_kextract(bpage->vaddr);
1097 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1098 total_bounce_pages++;
1109 /* Assume caller holds bounce zone spinlock */
1111 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1113 struct bounce_zone *bz = dmat->bounce_zone;
1116 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1117 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1118 bz->reserve_failed++;
1119 return (map->pagesneeded - (map->pagesreserved + pages));
1122 bz->free_bpages -= pages;
1124 bz->reserved_bpages += pages;
1125 KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1127 map->pagesreserved += pages;
1128 pages = map->pagesneeded - map->pagesreserved;
1134 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1136 struct bounce_zone *bz = dmat->bounce_zone;
1137 int reserved = map->pagesreserved;
1138 bus_dmamap_t wait_map;
1140 map->pagesreserved = 0;
1141 map->pagesneeded = 0;
1148 bz->free_bpages += reserved;
1149 KKASSERT(bz->free_bpages <= bz->total_bpages);
1151 KKASSERT(bz->reserved_bpages >= reserved);
1152 bz->reserved_bpages -= reserved;
1154 wait_map = get_map_waiting(dmat);
1158 if (wait_map != NULL)
1159 add_map_callback(map);
1163 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1166 struct bounce_zone *bz = dmat->bounce_zone;
1167 struct bounce_page *bpage;
1169 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1172 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1173 map->pagesreserved--;
1177 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1178 KASSERT(bpage != NULL, ("free page list is empty"));
1179 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1181 KKASSERT(bz->reserved_bpages > 0);
1182 bz->reserved_bpages--;
1184 bz->active_bpages++;
1185 KKASSERT(bz->active_bpages <= bz->total_bpages);
1189 bpage->datavaddr = vaddr;
1190 bpage->datacount = size;
1191 STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1192 return bpage->busaddr;
1196 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1198 struct bounce_zone *bz = dmat->bounce_zone;
1201 bpage->datavaddr = 0;
1202 bpage->datacount = 0;
1206 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1209 KKASSERT(bz->free_bpages <= bz->total_bpages);
1211 KKASSERT(bz->active_bpages > 0);
1212 bz->active_bpages--;
1214 map = get_map_waiting(dmat);
1219 add_map_callback(map);
1222 /* Assume caller holds bounce zone spinlock */
1224 get_map_waiting(bus_dma_tag_t dmat)
1226 struct bounce_zone *bz = dmat->bounce_zone;
1229 map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1231 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1232 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1233 bz->total_deferred++;
1242 add_map_callback(bus_dmamap_t map)
1245 /* XXX callbacklist is not MPSAFE */
1248 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1249 busdma_swi_pending = 1;
1254 panic("%s uncoded", __func__);
1265 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1266 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1268 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1269 map->callback, map->callback_arg, /*flags*/0);