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
57 * 16 x N declared on stack.
59 #define BUS_DMA_CACHE_SEGMENTS 8
70 bus_dma_filter_t *filter;
78 bus_dma_segment_t *segments;
79 struct bounce_zone *bounce_zone;
88 * bus_dma_tag private flags
90 #define BUS_DMA_BOUNCE_ALIGN BUS_DMA_BUS2
91 #define BUS_DMA_BOUNCE_LOWADDR BUS_DMA_BUS3
92 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
94 #define BUS_DMA_COULD_BOUNCE (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
96 #define BUS_DMAMEM_KMALLOC(dmat) \
97 ((dmat)->maxsize <= PAGE_SIZE && \
98 (dmat)->alignment <= PAGE_SIZE && \
99 (dmat)->lowaddr >= ptoa(Maxmem))
102 vm_offset_t vaddr; /* kva of bounce buffer */
103 bus_addr_t busaddr; /* Physical address */
104 vm_offset_t datavaddr; /* kva of client data */
105 bus_size_t datacount; /* client data count */
106 STAILQ_ENTRY(bounce_page) links;
110 STAILQ_ENTRY(bounce_zone) links;
111 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
112 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
114 struct spinlock spin;
125 bus_size_t alignment;
129 struct sysctl_ctx_list sysctl_ctx;
130 struct sysctl_oid *sysctl_tree;
134 #define BZ_LOCK(bz) spin_lock(&(bz)->spin)
135 #define BZ_UNLOCK(bz) spin_unlock(&(bz)->spin)
137 #define BZ_LOCK(bz) crit_enter()
138 #define BZ_UNLOCK(bz) crit_exit()
141 static struct lwkt_token bounce_zone_tok =
142 LWKT_TOKEN_INITIALIZER(bounce_zone_token);
143 static int busdma_zonecount;
144 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
145 STAILQ_HEAD_INITIALIZER(bounce_zone_list);
147 static int busdma_priv_zonecount = -1;
149 int busdma_swi_pending;
150 static int total_bounce_pages;
151 static int max_bounce_pages = MAX_BPAGES;
152 static int bounce_alignment = 1; /* XXX temporary */
154 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
155 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
158 struct bp_list bpages;
162 void *buf; /* unmapped buffer pointer */
163 bus_size_t buflen; /* unmapped buffer length */
164 bus_dmamap_callback_t *callback;
166 STAILQ_ENTRY(bus_dmamap) links;
169 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
170 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
171 static struct spinlock bounce_map_list_spin =
172 SPINLOCK_INITIALIZER(&bounce_map_list_spin);
174 static struct bus_dmamap nobounce_dmamap;
176 static int alloc_bounce_zone(bus_dma_tag_t);
177 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int);
178 static void free_bounce_pages_all(bus_dma_tag_t);
179 static void free_bounce_zone(bus_dma_tag_t);
180 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
181 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
182 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
183 vm_offset_t, bus_size_t);
184 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
186 static bus_dmamap_t get_map_waiting(bus_dma_tag_t);
187 static void add_map_callback(bus_dmamap_t);
189 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
190 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
191 0, "Total bounce pages");
192 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
193 0, "Max bounce pages per bounce zone");
194 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
195 &bounce_alignment, 0, "Obey alignment constraint");
198 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
204 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
205 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
206 && (dmat->filter == NULL ||
207 dmat->filter(dmat->filterarg, paddr) != 0))
211 } while (retval == 0 && dmat != NULL);
217 bus_dma_tag_lock(bus_dma_tag_t tag, bus_dma_segment_t *cache)
219 if (tag->flags & BUS_DMA_PROTECTED)
220 return(tag->segments);
222 if (tag->nsegments <= BUS_DMA_CACHE_SEGMENTS)
225 spin_lock(&tag->spin);
227 return(tag->segments);
232 bus_dma_tag_unlock(bus_dma_tag_t tag)
235 if (tag->flags & BUS_DMA_PROTECTED)
238 if (tag->nsegments > BUS_DMA_CACHE_SEGMENTS)
239 spin_unlock(&tag->spin);
244 * Allocate a device specific dma_tag.
247 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
248 bus_size_t boundary, bus_addr_t lowaddr,
249 bus_addr_t highaddr, bus_dma_filter_t *filter,
250 void *filterarg, bus_size_t maxsize, int nsegments,
251 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
253 bus_dma_tag_t newtag;
262 if (alignment & (alignment - 1))
263 panic("alignment must be power of 2\n");
266 if (boundary & (boundary - 1))
267 panic("boundary must be power of 2\n");
268 if (boundary < maxsegsz) {
269 kprintf("boundary < maxsegsz:\n");
275 /* Return a NULL tag on failure */
278 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT | M_ZERO);
281 spin_init(&newtag->spin);
283 newtag->parent = parent;
284 newtag->alignment = alignment;
285 newtag->boundary = boundary;
286 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
287 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
288 newtag->filter = filter;
289 newtag->filterarg = filterarg;
290 newtag->maxsize = maxsize;
291 newtag->nsegments = nsegments;
292 newtag->maxsegsz = maxsegsz;
293 newtag->flags = flags;
294 newtag->ref_count = 1; /* Count ourself */
295 newtag->map_count = 0;
296 newtag->segments = NULL;
297 newtag->bounce_zone = NULL;
299 /* Take into account any restrictions imposed by our parent tag */
300 if (parent != NULL) {
301 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
302 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
304 if (newtag->boundary == 0) {
305 newtag->boundary = parent->boundary;
306 } else if (parent->boundary != 0) {
307 newtag->boundary = MIN(parent->boundary,
312 newtag->alignment = MAX(parent->alignment, newtag->alignment);
315 if (newtag->filter == NULL) {
317 * Short circuit looking at our parent directly
318 * since we have encapsulated all of its information
320 newtag->filter = parent->filter;
321 newtag->filterarg = parent->filterarg;
322 newtag->parent = parent->parent;
324 if (newtag->parent != NULL)
328 if (newtag->lowaddr < ptoa(Maxmem))
329 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
330 if (bounce_alignment && newtag->alignment > 1 &&
331 !(newtag->flags & BUS_DMA_ALIGNED))
332 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
334 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
335 (flags & BUS_DMA_ALLOCNOW) != 0) {
336 struct bounce_zone *bz;
340 error = alloc_bounce_zone(newtag);
343 bz = newtag->bounce_zone;
345 if ((newtag->flags & BUS_DMA_ALLOCALL) == 0 &&
346 ptoa(bz->total_bpages) < maxsize) {
349 if (flags & BUS_DMA_ONEBPAGE) {
352 pages = atop(round_page(maxsize)) -
354 pages = MAX(pages, 1);
357 /* Add pages to our bounce pool */
358 if (alloc_bounce_pages(newtag, pages, flags) < pages)
361 /* Performed initial allocation */
362 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
367 free_bounce_zone(newtag);
368 kfree(newtag, M_DEVBUF);
376 bus_dma_tag_destroy(bus_dma_tag_t dmat)
379 if (dmat->map_count != 0)
382 while (dmat != NULL) {
383 bus_dma_tag_t parent;
385 parent = dmat->parent;
387 if (dmat->ref_count == 0) {
388 free_bounce_zone(dmat);
389 if (dmat->segments != NULL)
390 kfree(dmat->segments, M_DEVBUF);
391 kfree(dmat, M_DEVBUF);
393 * Last reference count, so
394 * release our reference
395 * count on our parent.
406 bus_dma_tag_getmaxsize(bus_dma_tag_t tag)
408 return(tag->maxsize);
412 * Allocate a handle for mapping from kva/uva/physical
413 * address space into bus device space.
416 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
422 if (dmat->segments == NULL) {
423 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
424 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
425 dmat->nsegments, M_DEVBUF, M_INTWAIT);
428 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
429 struct bounce_zone *bz;
434 if (dmat->bounce_zone == NULL) {
435 error = alloc_bounce_zone(dmat);
439 bz = dmat->bounce_zone;
441 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
443 /* Initialize the new map */
444 STAILQ_INIT(&((*mapp)->bpages));
447 * Attempt to add pages to our pool on a per-instance
448 * basis up to a sane limit.
450 if (dmat->flags & BUS_DMA_ALLOCALL) {
451 maxpages = Maxmem - atop(dmat->lowaddr);
452 } else if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
453 maxpages = max_bounce_pages;
455 maxpages = MIN(max_bounce_pages,
456 Maxmem - atop(dmat->lowaddr));
458 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
459 (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
462 if (flags & BUS_DMA_ONEBPAGE) {
465 pages = atop(round_page(dmat->maxsize));
466 pages = MIN(maxpages - bz->total_bpages, pages);
467 pages = MAX(pages, 1);
469 if (alloc_bounce_pages(dmat, pages, flags) < pages)
472 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
474 (dmat->flags & BUS_DMA_ALLOCALL) == 0)
475 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
486 kfree(*mapp, M_DEVBUF);
493 * Destroy a handle for mapping from kva/uva/physical
494 * address space into bus device space.
497 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
500 if (STAILQ_FIRST(&map->bpages) != NULL)
502 kfree(map, M_DEVBUF);
508 static __inline bus_size_t
509 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
511 bus_size_t maxsize = 0;
512 uintptr_t vaddr = (uintptr_t)vaddr0;
514 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
515 if (verify || bootverbose)
516 kprintf("boundary check failed\n");
518 print_backtrace(-1); /* XXX panic */
519 maxsize = dmat->maxsize;
521 if (vaddr & (dmat->alignment - 1)) {
522 if (verify || bootverbose)
523 kprintf("alignment check failed\n");
525 print_backtrace(-1); /* XXX panic */
526 if (dmat->maxsize < dmat->alignment)
527 maxsize = dmat->alignment;
529 maxsize = dmat->maxsize;
535 * Allocate a piece of memory that can be efficiently mapped into
536 * bus device space based on the constraints lited in the dma tag.
538 * mapp is degenerate. By definition this allocation should not require
539 * bounce buffers so do not allocate a dma map.
542 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
547 /* If we succeed, no mapping/bouncing will be required */
550 if (dmat->segments == NULL) {
551 KKASSERT(dmat->nsegments < 16384);
552 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
553 dmat->nsegments, M_DEVBUF, M_INTWAIT);
556 if (flags & BUS_DMA_NOWAIT)
560 if (flags & BUS_DMA_ZERO)
563 if (BUS_DMAMEM_KMALLOC(dmat)) {
566 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
570 * Check whether the allocation
571 * - crossed a page boundary
573 * Retry with power-of-2 alignment in the above cases.
575 maxsize = check_kmalloc(dmat, *vaddr, 0);
579 kfree(*vaddr, M_DEVBUF);
580 /* XXX check for overflow? */
581 for (size = 1; size <= maxsize; size <<= 1)
583 *vaddr = kmalloc(size, M_DEVBUF, mflags);
584 check_kmalloc(dmat, *vaddr, 1);
588 * XXX Use Contigmalloc until it is merged into this facility
589 * and handles multi-seg allocations. Nobody is doing
590 * multi-seg allocations yet though.
592 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
593 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
601 * Free a piece of memory and it's allociated dmamap, that was allocated
602 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
605 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
608 * dmamem does not need to be bounced, so the map should be
612 panic("bus_dmamem_free: Invalid map freed\n");
613 if (BUS_DMAMEM_KMALLOC(dmat))
614 kfree(vaddr, M_DEVBUF);
616 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
619 static __inline vm_paddr_t
620 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
623 return pmap_extract(pmap, vaddr);
625 return pmap_kextract(vaddr);
629 * Utility function to load a linear buffer. lastaddrp holds state
630 * between invocations (for multiple-buffer loads). segp contains
631 * the segment following the starting one on entrace, and the ending
632 * segment on exit. first indicates if this is the first invocation
636 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
638 void *buf, bus_size_t buflen,
639 bus_dma_segment_t *segments,
643 vm_paddr_t *lastpaddrp,
648 vm_paddr_t paddr, nextpaddr;
649 bus_dma_segment_t *sg;
654 map = &nobounce_dmamap;
657 if (dmat->flags & BUS_DMA_ALIGNED)
658 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
662 * If we are being called during a callback, pagesneeded will
663 * be non-zero, so we can avoid doing the work twice.
665 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
666 map != &nobounce_dmamap && map->pagesneeded == 0) {
667 vm_offset_t vendaddr;
670 * Count the number of bounce pages
671 * needed in order to complete this transfer
673 vaddr = (vm_offset_t)buf;
674 vendaddr = (vm_offset_t)buf + buflen;
676 while (vaddr < vendaddr) {
677 paddr = _bus_dma_extract(pmap, vaddr);
678 if (run_filter(dmat, paddr) != 0)
680 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
684 /* Reserve Necessary Bounce Pages */
685 if (map->pagesneeded != 0) {
686 struct bounce_zone *bz;
688 bz = dmat->bounce_zone;
690 if (flags & BUS_DMA_NOWAIT) {
691 if (reserve_bounce_pages(dmat, map, 0) != 0) {
697 if (reserve_bounce_pages(dmat, map, 1) != 0) {
698 /* Queue us for resources */
701 map->buflen = buflen;
704 &dmat->bounce_zone->bounce_map_waitinglist,
708 return (EINPROGRESS);
714 KKASSERT(*segp >= 1 && *segp <= nsegments);
716 sg = &segments[seg - 1];
718 vaddr = (vm_offset_t)buf;
719 nextpaddr = *lastpaddrp;
720 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
722 /* force at least one segment */
729 paddr = _bus_dma_extract(pmap, vaddr);
730 size = PAGE_SIZE - (paddr & PAGE_MASK);
733 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
735 * note: this paddr has the same in-page offset
736 * as vaddr and thus the paddr above, so the
737 * size does not have to be recalculated
739 paddr = add_bounce_page(dmat, map, vaddr, size);
743 * Fill in the bus_dma_segment
749 } else if (paddr == nextpaddr) {
759 nextpaddr = paddr + size;
762 * Handle maxsegsz and boundary issues with a nested loop
768 * Limit to the boundary and maximum segment size
770 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
771 tmpsize = dmat->boundary -
772 (sg->ds_addr & ~bmask);
773 if (tmpsize > dmat->maxsegsz)
774 tmpsize = dmat->maxsegsz;
775 KKASSERT(tmpsize < sg->ds_len);
776 } else if (sg->ds_len > dmat->maxsegsz) {
777 tmpsize = dmat->maxsegsz;
783 * Futz, split the data into a new segment.
785 if (seg >= nsegments)
787 sg[1].ds_len = sg[0].ds_len - tmpsize;
788 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
789 sg[0].ds_len = tmpsize;
799 } while (buflen > 0);
805 *lastpaddrp = nextpaddr;
808 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
809 map != &nobounce_dmamap) {
810 _bus_dmamap_unload(dmat, map);
811 return_bounce_pages(dmat, map);
817 * Map the buffer buf into bus space using the dmamap map.
820 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
821 bus_size_t buflen, bus_dmamap_callback_t *callback,
822 void *callback_arg, int flags)
824 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
825 bus_dma_segment_t *segments;
826 vm_paddr_t lastaddr = 0;
827 int error, nsegs = 1;
832 * Follow old semantics. Once all of the callers are fixed,
833 * we should get rid of these internal flag "adjustment".
835 flags &= ~BUS_DMA_NOWAIT;
836 flags |= BUS_DMA_WAITOK;
838 map->callback = callback;
839 map->callback_arg = callback_arg;
842 segments = bus_dma_tag_lock(dmat, cache_segments);
843 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
844 segments, dmat->nsegments,
845 NULL, flags, &lastaddr, &nsegs, 1);
846 if (error == EINPROGRESS) {
847 KKASSERT((dmat->flags &
848 (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL)) !=
849 (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL));
851 if (dmat->flags & BUS_DMA_PROTECTED)
852 panic("protected dmamap callback will be defered\n");
854 bus_dma_tag_unlock(dmat);
857 callback(callback_arg, segments, nsegs, error);
858 bus_dma_tag_unlock(dmat);
863 * Like _bus_dmamap_load(), but for mbufs.
866 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
868 bus_dmamap_callback2_t *callback, void *callback_arg,
871 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
872 bus_dma_segment_t *segments;
877 * Follow old semantics. Once all of the callers are fixed,
878 * we should get rid of these internal flag "adjustment".
880 flags &= ~BUS_DMA_WAITOK;
881 flags |= BUS_DMA_NOWAIT;
883 segments = bus_dma_tag_lock(dmat, cache_segments);
884 error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
885 segments, dmat->nsegments, &nsegs, flags);
887 /* force "no valid mappings" in callback */
888 callback(callback_arg, segments, 0,
891 callback(callback_arg, segments, nsegs,
892 m0->m_pkthdr.len, error);
894 bus_dma_tag_unlock(dmat);
899 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
901 bus_dma_segment_t *segs, int maxsegs,
902 int *nsegs, int flags)
908 KASSERT(maxsegs >= 1, ("invalid maxsegs %d\n", maxsegs));
909 KASSERT(maxsegs <= dmat->nsegments,
910 ("%d too many segments, dmat only support %d segments\n",
911 maxsegs, dmat->nsegments));
912 KASSERT(flags & BUS_DMA_NOWAIT,
913 ("only BUS_DMA_NOWAIT is supported\n"));
915 if (m0->m_pkthdr.len <= dmat->maxsize) {
917 vm_paddr_t lastaddr = 0;
922 for (m = m0; m != NULL && error == 0; m = m->m_next) {
926 error = _bus_dmamap_load_buffer(dmat, map,
929 NULL, flags, &lastaddr,
931 if (error == ENOMEM && !first) {
933 * Out of bounce pages due to too many
934 * fragments in the mbuf chain; return
943 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
949 KKASSERT(error != EINPROGRESS);
954 * Like _bus_dmamap_load(), but for uios.
957 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
959 bus_dmamap_callback2_t *callback, void *callback_arg,
963 int nsegs, error, first, i;
967 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
968 bus_dma_segment_t *segments;
969 bus_dma_segment_t *segs;
972 if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS)
973 segments = cache_segments;
975 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments,
976 M_DEVBUF, M_WAITOK | M_ZERO);
980 * Follow old semantics. Once all of the callers are fixed,
981 * we should get rid of these internal flag "adjustment".
983 flags &= ~BUS_DMA_WAITOK;
984 flags |= BUS_DMA_NOWAIT;
986 resid = (bus_size_t)uio->uio_resid;
990 nsegs_left = dmat->nsegments;
992 if (uio->uio_segflg == UIO_USERSPACE) {
996 KASSERT(td != NULL && td->td_proc != NULL,
997 ("bus_dmamap_load_uio: USERSPACE but no proc"));
998 pmap = vmspace_pmap(td->td_proc->p_vmspace);
1007 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
1009 * Now at the first iovec to load. Load each iovec
1010 * until we have exhausted the residual count.
1013 resid < iov[i].iov_len ? resid : iov[i].iov_len;
1014 caddr_t addr = (caddr_t) iov[i].iov_base;
1016 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
1018 pmap, flags, &lastaddr, &nsegs, first);
1023 nsegs_left -= nsegs;
1029 * Minimum one DMA segment, even if 0-length buffer.
1031 if (nsegs_left == dmat->nsegments)
1035 /* force "no valid mappings" in callback */
1036 callback(callback_arg, segments, 0,
1039 callback(callback_arg, segments, dmat->nsegments - nsegs_left,
1040 (bus_size_t)uio->uio_resid, error);
1042 if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS)
1043 kfree(segments, M_DEVBUF);
1048 * Release the mapping held by map.
1051 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1053 struct bounce_page *bpage;
1055 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1056 STAILQ_REMOVE_HEAD(&map->bpages, links);
1057 free_bounce_page(dmat, bpage);
1062 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1064 struct bounce_page *bpage;
1066 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1068 * Handle data bouncing. We might also
1069 * want to add support for invalidating
1070 * the caches on broken hardware
1073 case BUS_DMASYNC_PREWRITE:
1074 while (bpage != NULL) {
1075 bcopy((void *)bpage->datavaddr,
1076 (void *)bpage->vaddr,
1078 bpage = STAILQ_NEXT(bpage, links);
1080 dmat->bounce_zone->total_bounced++;
1083 case BUS_DMASYNC_POSTREAD:
1084 while (bpage != NULL) {
1085 bcopy((void *)bpage->vaddr,
1086 (void *)bpage->datavaddr,
1088 bpage = STAILQ_NEXT(bpage, links);
1090 dmat->bounce_zone->total_bounced++;
1093 case BUS_DMASYNC_PREREAD:
1094 case BUS_DMASYNC_POSTWRITE:
1102 alloc_bounce_zone(bus_dma_tag_t dmat)
1104 struct bounce_zone *bz, *new_bz;
1106 KASSERT(dmat->bounce_zone == NULL,
1107 ("bounce zone was already assigned\n"));
1109 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1111 lwkt_gettoken(&bounce_zone_tok);
1113 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1115 * For shared bounce zone, check to see
1116 * if we already have a suitable zone
1118 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1119 if (dmat->alignment <= bz->alignment &&
1120 dmat->lowaddr >= bz->lowaddr) {
1121 lwkt_reltoken(&bounce_zone_tok);
1123 dmat->bounce_zone = bz;
1124 kfree(new_bz, M_DEVBUF);
1132 spin_init(&bz->spin);
1134 STAILQ_INIT(&bz->bounce_page_list);
1135 STAILQ_INIT(&bz->bounce_map_waitinglist);
1136 bz->free_bpages = 0;
1137 bz->reserved_bpages = 0;
1138 bz->active_bpages = 0;
1139 bz->lowaddr = dmat->lowaddr;
1140 bz->alignment = round_page(dmat->alignment);
1141 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1143 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1144 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1146 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1148 ksnprintf(bz->zoneid, 8, "zone%d", busdma_priv_zonecount);
1149 busdma_priv_zonecount--;
1152 lwkt_reltoken(&bounce_zone_tok);
1154 dmat->bounce_zone = bz;
1156 sysctl_ctx_init(&bz->sysctl_ctx);
1157 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1158 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1160 if (bz->sysctl_tree == NULL) {
1161 sysctl_ctx_free(&bz->sysctl_ctx);
1162 return 0; /* XXX error code? */
1165 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1166 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1167 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1168 "Total bounce pages");
1169 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1170 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1171 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1172 "Free bounce pages");
1173 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1174 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1175 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1176 "Reserved bounce pages");
1177 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1178 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1179 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1180 "Active bounce pages");
1181 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1182 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1183 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1184 "Total bounce requests");
1185 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1186 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1187 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1188 "Total bounce requests that were deferred");
1189 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1190 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1191 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1192 "Total bounce page reservations that were failed");
1193 SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1194 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1195 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1196 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1197 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1198 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1204 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1206 struct bounce_zone *bz = dmat->bounce_zone;
1207 int count = 0, mflags;
1209 if (flags & BUS_DMA_NOWAIT)
1214 while (numpages > 0) {
1215 struct bounce_page *bpage;
1217 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1219 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1223 if (bpage->vaddr == 0) {
1224 kfree(bpage, M_DEVBUF);
1227 bpage->busaddr = pmap_kextract(bpage->vaddr);
1230 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1231 total_bounce_pages++;
1243 free_bounce_pages_all(bus_dma_tag_t dmat)
1245 struct bounce_zone *bz = dmat->bounce_zone;
1246 struct bounce_page *bpage;
1250 while ((bpage = STAILQ_FIRST(&bz->bounce_page_list)) != NULL) {
1251 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1253 KKASSERT(total_bounce_pages > 0);
1254 total_bounce_pages--;
1256 KKASSERT(bz->total_bpages > 0);
1259 KKASSERT(bz->free_bpages > 0);
1263 contigfree((void *)bpage->vaddr, PAGE_SIZE, M_DEVBUF);
1264 kfree(bpage, M_DEVBUF);
1267 if (bz->total_bpages) {
1268 kprintf("#%d bounce pages are still in use\n",
1270 print_backtrace(-1);
1277 free_bounce_zone(bus_dma_tag_t dmat)
1279 struct bounce_zone *bz = dmat->bounce_zone;
1284 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0)
1287 free_bounce_pages_all(dmat);
1288 dmat->bounce_zone = NULL;
1290 if (bz->sysctl_tree != NULL)
1291 sysctl_ctx_free(&bz->sysctl_ctx);
1292 kfree(bz, M_DEVBUF);
1295 /* Assume caller holds bounce zone spinlock */
1297 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1299 struct bounce_zone *bz = dmat->bounce_zone;
1302 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1303 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1304 bz->reserve_failed++;
1305 return (map->pagesneeded - (map->pagesreserved + pages));
1308 bz->free_bpages -= pages;
1310 bz->reserved_bpages += pages;
1311 KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1313 map->pagesreserved += pages;
1314 pages = map->pagesneeded - map->pagesreserved;
1320 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1322 struct bounce_zone *bz = dmat->bounce_zone;
1323 int reserved = map->pagesreserved;
1324 bus_dmamap_t wait_map;
1326 map->pagesreserved = 0;
1327 map->pagesneeded = 0;
1334 bz->free_bpages += reserved;
1335 KKASSERT(bz->free_bpages <= bz->total_bpages);
1337 KKASSERT(bz->reserved_bpages >= reserved);
1338 bz->reserved_bpages -= reserved;
1340 wait_map = get_map_waiting(dmat);
1344 if (wait_map != NULL)
1345 add_map_callback(map);
1349 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1352 struct bounce_zone *bz = dmat->bounce_zone;
1353 struct bounce_page *bpage;
1355 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1358 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1359 map->pagesreserved--;
1363 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1364 KASSERT(bpage != NULL, ("free page list is empty"));
1365 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1367 KKASSERT(bz->reserved_bpages > 0);
1368 bz->reserved_bpages--;
1370 bz->active_bpages++;
1371 KKASSERT(bz->active_bpages <= bz->total_bpages);
1375 bpage->datavaddr = vaddr;
1376 bpage->datacount = size;
1377 STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1378 return bpage->busaddr;
1382 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1384 struct bounce_zone *bz = dmat->bounce_zone;
1387 bpage->datavaddr = 0;
1388 bpage->datacount = 0;
1392 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1395 KKASSERT(bz->free_bpages <= bz->total_bpages);
1397 KKASSERT(bz->active_bpages > 0);
1398 bz->active_bpages--;
1400 map = get_map_waiting(dmat);
1405 add_map_callback(map);
1408 /* Assume caller holds bounce zone spinlock */
1410 get_map_waiting(bus_dma_tag_t dmat)
1412 struct bounce_zone *bz = dmat->bounce_zone;
1415 map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1417 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1418 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1419 bz->total_deferred++;
1428 add_map_callback(bus_dmamap_t map)
1430 spin_lock(&bounce_map_list_spin);
1431 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1432 busdma_swi_pending = 1;
1434 spin_unlock(&bounce_map_list_spin);
1442 spin_lock(&bounce_map_list_spin);
1443 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1444 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1445 spin_unlock(&bounce_map_list_spin);
1446 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1447 map->callback, map->callback_arg, /*flags*/0);
1448 spin_lock(&bounce_map_list_spin);
1450 spin_unlock(&bounce_map_list_spin);