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/bus_dma.h>
35 #include <sys/kernel.h>
36 #include <sys/sysctl.h>
39 #include <sys/thread2.h>
40 #include <sys/spinlock2.h>
41 #include <sys/mplock2.h>
44 #include <vm/vm_page.h>
46 /* XXX needed for to access pmap to convert per-proc virtual to physical */
49 #include <vm/vm_map.h>
51 #include <machine/md_var.h>
53 #define MAX_BPAGES 1024
56 * 16 x N declared on stack.
58 #define BUS_DMA_CACHE_SEGMENTS 8
69 bus_dma_filter_t *filter;
77 bus_dma_segment_t *segments;
78 struct bounce_zone *bounce_zone;
87 * bus_dma_tag private flags
89 #define BUS_DMA_BOUNCE_ALIGN BUS_DMA_BUS2
90 #define BUS_DMA_BOUNCE_LOWADDR BUS_DMA_BUS3
91 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
93 #define BUS_DMA_COULD_BOUNCE (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
95 #define BUS_DMAMEM_KMALLOC(dmat) \
96 ((dmat)->maxsize <= PAGE_SIZE && \
97 (dmat)->alignment <= PAGE_SIZE && \
98 (dmat)->lowaddr >= ptoa(Maxmem))
101 vm_offset_t vaddr; /* kva of bounce buffer */
102 bus_addr_t busaddr; /* Physical address */
103 vm_offset_t datavaddr; /* kva of client data */
104 bus_size_t datacount; /* client data count */
105 STAILQ_ENTRY(bounce_page) links;
109 STAILQ_ENTRY(bounce_zone) links;
110 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
111 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
113 struct spinlock spin;
124 bus_size_t alignment;
128 struct sysctl_ctx_list sysctl_ctx;
129 struct sysctl_oid *sysctl_tree;
133 #define BZ_LOCK(bz) spin_lock(&(bz)->spin)
134 #define BZ_UNLOCK(bz) spin_unlock(&(bz)->spin)
136 #define BZ_LOCK(bz) crit_enter()
137 #define BZ_UNLOCK(bz) crit_exit()
140 static struct lwkt_token bounce_zone_tok =
141 LWKT_TOKEN_INITIALIZER(bounce_zone_tok);
142 static int busdma_zonecount;
143 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
144 STAILQ_HEAD_INITIALIZER(bounce_zone_list);
146 static int busdma_priv_zonecount = -1;
148 int busdma_swi_pending;
149 static int total_bounce_pages;
150 static int max_bounce_pages = MAX_BPAGES;
151 static int bounce_alignment = 1; /* XXX temporary */
153 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
154 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
157 struct bp_list bpages;
161 void *buf; /* unmapped buffer pointer */
162 bus_size_t buflen; /* unmapped buffer length */
163 bus_dmamap_callback_t *callback;
165 STAILQ_ENTRY(bus_dmamap) links;
168 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
169 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
170 static struct spinlock bounce_map_list_spin =
171 SPINLOCK_INITIALIZER(&bounce_map_list_spin);
173 static struct bus_dmamap nobounce_dmamap;
175 static int alloc_bounce_zone(bus_dma_tag_t);
176 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int);
177 static void free_bounce_pages_all(bus_dma_tag_t);
178 static void free_bounce_zone(bus_dma_tag_t);
179 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
180 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
181 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
182 vm_offset_t, bus_size_t);
183 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
185 static bus_dmamap_t get_map_waiting(bus_dma_tag_t);
186 static void add_map_callback(bus_dmamap_t);
188 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
189 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
190 0, "Total bounce pages");
191 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
192 0, "Max bounce pages per bounce zone");
193 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
194 &bounce_alignment, 0, "Obey alignment constraint");
197 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
203 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
204 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
205 && (dmat->filter == NULL ||
206 dmat->filter(dmat->filterarg, paddr) != 0))
210 } while (retval == 0 && dmat != NULL);
216 bus_dma_tag_lock(bus_dma_tag_t tag, bus_dma_segment_t *cache)
218 if (tag->flags & BUS_DMA_PROTECTED)
219 return(tag->segments);
221 if (tag->nsegments <= BUS_DMA_CACHE_SEGMENTS)
224 spin_lock(&tag->spin);
226 return(tag->segments);
231 bus_dma_tag_unlock(bus_dma_tag_t tag)
234 if (tag->flags & BUS_DMA_PROTECTED)
237 if (tag->nsegments > BUS_DMA_CACHE_SEGMENTS)
238 spin_unlock(&tag->spin);
243 * Allocate a device specific dma_tag.
246 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
247 bus_size_t boundary, bus_addr_t lowaddr,
248 bus_addr_t highaddr, bus_dma_filter_t *filter,
249 void *filterarg, bus_size_t maxsize, int nsegments,
250 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
252 bus_dma_tag_t newtag;
261 if (alignment & (alignment - 1))
262 panic("alignment must be power of 2");
265 if (boundary & (boundary - 1))
266 panic("boundary must be power of 2");
267 if (boundary < maxsegsz) {
268 kprintf("boundary < maxsegsz:\n");
274 /* Return a NULL tag on failure */
277 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT | M_ZERO);
280 spin_init(&newtag->spin);
282 newtag->parent = parent;
283 newtag->alignment = alignment;
284 newtag->boundary = boundary;
285 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
286 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
287 newtag->filter = filter;
288 newtag->filterarg = filterarg;
289 newtag->maxsize = maxsize;
290 newtag->nsegments = nsegments;
291 newtag->maxsegsz = maxsegsz;
292 newtag->flags = flags;
293 newtag->ref_count = 1; /* Count ourself */
294 newtag->map_count = 0;
295 newtag->segments = NULL;
296 newtag->bounce_zone = NULL;
298 /* Take into account any restrictions imposed by our parent tag */
299 if (parent != NULL) {
300 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
301 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
303 if (newtag->boundary == 0) {
304 newtag->boundary = parent->boundary;
305 } else if (parent->boundary != 0) {
306 newtag->boundary = MIN(parent->boundary,
311 newtag->alignment = MAX(parent->alignment, newtag->alignment);
314 if (newtag->filter == NULL) {
316 * Short circuit looking at our parent directly
317 * since we have encapsulated all of its information
319 newtag->filter = parent->filter;
320 newtag->filterarg = parent->filterarg;
321 newtag->parent = parent->parent;
323 if (newtag->parent != NULL)
327 if (newtag->lowaddr < ptoa(Maxmem))
328 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
329 if (bounce_alignment && newtag->alignment > 1 &&
330 !(newtag->flags & BUS_DMA_ALIGNED))
331 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
333 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
334 (flags & BUS_DMA_ALLOCNOW) != 0) {
335 struct bounce_zone *bz;
339 error = alloc_bounce_zone(newtag);
342 bz = newtag->bounce_zone;
344 if ((newtag->flags & BUS_DMA_ALLOCALL) == 0 &&
345 ptoa(bz->total_bpages) < maxsize) {
348 if (flags & BUS_DMA_ONEBPAGE) {
351 pages = atop(round_page(maxsize)) -
353 pages = MAX(pages, 1);
356 /* Add pages to our bounce pool */
357 if (alloc_bounce_pages(newtag, pages, flags) < pages)
360 /* Performed initial allocation */
361 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
366 free_bounce_zone(newtag);
367 kfree(newtag, M_DEVBUF);
375 bus_dma_tag_destroy(bus_dma_tag_t dmat)
378 if (dmat->map_count != 0)
381 while (dmat != NULL) {
382 bus_dma_tag_t parent;
384 parent = dmat->parent;
386 if (dmat->ref_count == 0) {
387 free_bounce_zone(dmat);
388 if (dmat->segments != NULL)
389 kfree(dmat->segments, M_DEVBUF);
390 kfree(dmat, M_DEVBUF);
392 * Last reference count, so
393 * release our reference
394 * count on our parent.
405 bus_dma_tag_getmaxsize(bus_dma_tag_t tag)
407 return(tag->maxsize);
411 * Allocate a handle for mapping from kva/uva/physical
412 * address space into bus device space.
415 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
421 if (dmat->segments == NULL) {
422 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
423 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
424 dmat->nsegments, M_DEVBUF, M_INTWAIT);
427 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
428 struct bounce_zone *bz;
433 if (dmat->bounce_zone == NULL) {
434 error = alloc_bounce_zone(dmat);
438 bz = dmat->bounce_zone;
440 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
442 /* Initialize the new map */
443 STAILQ_INIT(&((*mapp)->bpages));
446 * Attempt to add pages to our pool on a per-instance
447 * basis up to a sane limit.
449 if (dmat->flags & BUS_DMA_ALLOCALL) {
450 maxpages = Maxmem - atop(dmat->lowaddr);
451 } else if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
452 maxpages = max_bounce_pages;
454 maxpages = MIN(max_bounce_pages,
455 Maxmem - atop(dmat->lowaddr));
457 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
458 (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
461 if (flags & BUS_DMA_ONEBPAGE) {
464 pages = atop(round_page(dmat->maxsize));
465 pages = MIN(maxpages - bz->total_bpages, pages);
466 pages = MAX(pages, 1);
468 if (alloc_bounce_pages(dmat, pages, flags) < pages)
471 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
473 (dmat->flags & BUS_DMA_ALLOCALL) == 0)
474 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
485 kfree(*mapp, M_DEVBUF);
492 * Destroy a handle for mapping from kva/uva/physical
493 * address space into bus device space.
496 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
499 if (STAILQ_FIRST(&map->bpages) != NULL)
501 kfree(map, M_DEVBUF);
507 static __inline bus_size_t
508 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
510 bus_size_t maxsize = 0;
511 uintptr_t vaddr = (uintptr_t)vaddr0;
513 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
514 if (verify || bootverbose)
515 kprintf("boundary check failed\n");
517 print_backtrace(-1); /* XXX panic */
518 maxsize = dmat->maxsize;
520 if (vaddr & (dmat->alignment - 1)) {
521 if (verify || bootverbose)
522 kprintf("alignment check failed\n");
524 print_backtrace(-1); /* XXX panic */
525 if (dmat->maxsize < dmat->alignment)
526 maxsize = dmat->alignment;
528 maxsize = dmat->maxsize;
534 * Allocate a piece of memory that can be efficiently mapped into
535 * bus device space based on the constraints lited in the dma tag.
537 * mapp is degenerate. By definition this allocation should not require
538 * bounce buffers so do not allocate a dma map.
541 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
546 /* If we succeed, no mapping/bouncing will be required */
549 if (dmat->segments == NULL) {
550 KKASSERT(dmat->nsegments < 16384);
551 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
552 dmat->nsegments, M_DEVBUF, M_INTWAIT);
555 if (flags & BUS_DMA_NOWAIT)
559 if (flags & BUS_DMA_ZERO)
562 if (BUS_DMAMEM_KMALLOC(dmat)) {
565 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
569 * Check whether the allocation
570 * - crossed a page boundary
572 * Retry with power-of-2 alignment in the above cases.
574 maxsize = check_kmalloc(dmat, *vaddr, 0);
578 kfree(*vaddr, M_DEVBUF);
579 /* XXX check for overflow? */
580 for (size = 1; size <= maxsize; size <<= 1)
582 *vaddr = kmalloc(size, M_DEVBUF, mflags);
583 check_kmalloc(dmat, *vaddr, 1);
587 * XXX Use Contigmalloc until it is merged into this facility
588 * and handles multi-seg allocations. Nobody is doing
589 * multi-seg allocations yet though.
591 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
592 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
600 * Free a piece of memory and it's allociated dmamap, that was allocated
601 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
604 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
607 * dmamem does not need to be bounced, so the map should be
611 panic("bus_dmamem_free: Invalid map freed");
612 if (BUS_DMAMEM_KMALLOC(dmat))
613 kfree(vaddr, M_DEVBUF);
615 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
618 static __inline vm_paddr_t
619 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
622 return pmap_extract(pmap, vaddr);
624 return pmap_kextract(vaddr);
628 * Utility function to load a linear buffer. lastaddrp holds state
629 * between invocations (for multiple-buffer loads). segp contains
630 * the segment following the starting one on entrace, and the ending
631 * segment on exit. first indicates if this is the first invocation
635 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
637 void *buf, bus_size_t buflen,
638 bus_dma_segment_t *segments,
642 vm_paddr_t *lastpaddrp,
647 vm_paddr_t paddr, nextpaddr;
648 bus_dma_segment_t *sg;
653 map = &nobounce_dmamap;
656 if (dmat->flags & BUS_DMA_ALIGNED)
657 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
661 * If we are being called during a callback, pagesneeded will
662 * be non-zero, so we can avoid doing the work twice.
664 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
665 map != &nobounce_dmamap && map->pagesneeded == 0) {
666 vm_offset_t vendaddr;
669 * Count the number of bounce pages
670 * needed in order to complete this transfer
672 vaddr = (vm_offset_t)buf;
673 vendaddr = (vm_offset_t)buf + buflen;
675 while (vaddr < vendaddr) {
676 paddr = _bus_dma_extract(pmap, vaddr);
677 if (run_filter(dmat, paddr) != 0)
679 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
683 /* Reserve Necessary Bounce Pages */
684 if (map->pagesneeded != 0) {
685 struct bounce_zone *bz;
687 bz = dmat->bounce_zone;
689 if (flags & BUS_DMA_NOWAIT) {
690 if (reserve_bounce_pages(dmat, map, 0) != 0) {
696 if (reserve_bounce_pages(dmat, map, 1) != 0) {
697 /* Queue us for resources */
700 map->buflen = buflen;
703 &dmat->bounce_zone->bounce_map_waitinglist,
707 return (EINPROGRESS);
713 KKASSERT(*segp >= 1 && *segp <= nsegments);
715 sg = &segments[seg - 1];
717 vaddr = (vm_offset_t)buf;
718 nextpaddr = *lastpaddrp;
719 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
721 /* force at least one segment */
728 paddr = _bus_dma_extract(pmap, vaddr);
729 size = PAGE_SIZE - (paddr & PAGE_MASK);
732 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
734 * note: this paddr has the same in-page offset
735 * as vaddr and thus the paddr above, so the
736 * size does not have to be recalculated
738 paddr = add_bounce_page(dmat, map, vaddr, size);
742 * Fill in the bus_dma_segment
748 } else if (paddr == nextpaddr) {
758 nextpaddr = paddr + size;
761 * Handle maxsegsz and boundary issues with a nested loop
767 * Limit to the boundary and maximum segment size
769 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
770 tmpsize = dmat->boundary -
771 (sg->ds_addr & ~bmask);
772 if (tmpsize > dmat->maxsegsz)
773 tmpsize = dmat->maxsegsz;
774 KKASSERT(tmpsize < sg->ds_len);
775 } else if (sg->ds_len > dmat->maxsegsz) {
776 tmpsize = dmat->maxsegsz;
782 * Futz, split the data into a new segment.
784 if (seg >= nsegments)
786 sg[1].ds_len = sg[0].ds_len - tmpsize;
787 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
788 sg[0].ds_len = tmpsize;
798 } while (buflen > 0);
804 *lastpaddrp = nextpaddr;
807 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
808 map != &nobounce_dmamap) {
809 _bus_dmamap_unload(dmat, map);
810 return_bounce_pages(dmat, map);
816 * Map the buffer buf into bus space using the dmamap map.
819 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
820 bus_size_t buflen, bus_dmamap_callback_t *callback,
821 void *callback_arg, int flags)
823 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
824 bus_dma_segment_t *segments;
825 vm_paddr_t lastaddr = 0;
826 int error, nsegs = 1;
831 * Follow old semantics. Once all of the callers are fixed,
832 * we should get rid of these internal flag "adjustment".
834 flags &= ~BUS_DMA_NOWAIT;
835 flags |= BUS_DMA_WAITOK;
837 map->callback = callback;
838 map->callback_arg = callback_arg;
841 segments = bus_dma_tag_lock(dmat, cache_segments);
842 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
843 segments, dmat->nsegments,
844 NULL, flags, &lastaddr, &nsegs, 1);
845 if (error == EINPROGRESS) {
846 KKASSERT((dmat->flags &
847 (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL)) !=
848 (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL));
850 if (dmat->flags & BUS_DMA_PROTECTED)
851 panic("protected dmamap callback will be defered");
853 bus_dma_tag_unlock(dmat);
856 callback(callback_arg, segments, nsegs, error);
857 bus_dma_tag_unlock(dmat);
862 * Like _bus_dmamap_load(), but for mbufs.
865 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
867 bus_dmamap_callback2_t *callback, void *callback_arg,
870 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
871 bus_dma_segment_t *segments;
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 segments = bus_dma_tag_lock(dmat, cache_segments);
883 error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
884 segments, dmat->nsegments, &nsegs, flags);
886 /* force "no valid mappings" in callback */
887 callback(callback_arg, segments, 0,
890 callback(callback_arg, segments, nsegs,
891 m0->m_pkthdr.len, error);
893 bus_dma_tag_unlock(dmat);
898 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
900 bus_dma_segment_t *segs, int maxsegs,
901 int *nsegs, int flags)
907 KASSERT(maxsegs >= 1, ("invalid maxsegs %d", maxsegs));
908 KASSERT(maxsegs <= dmat->nsegments,
909 ("%d too many segments, dmat only supports %d segments",
910 maxsegs, dmat->nsegments));
911 KASSERT(flags & BUS_DMA_NOWAIT,
912 ("only BUS_DMA_NOWAIT is supported"));
914 if (m0->m_pkthdr.len <= dmat->maxsize) {
916 vm_paddr_t lastaddr = 0;
921 for (m = m0; m != NULL && error == 0; m = m->m_next) {
925 error = _bus_dmamap_load_buffer(dmat, map,
928 NULL, flags, &lastaddr,
930 if (error == ENOMEM && !first) {
932 * Out of bounce pages due to too many
933 * fragments in the mbuf chain; return
942 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
948 KKASSERT(error != EINPROGRESS);
953 * Like _bus_dmamap_load(), but for uios.
956 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
958 bus_dmamap_callback2_t *callback, void *callback_arg,
962 int nsegs, error, first, i;
966 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
967 bus_dma_segment_t *segments;
968 bus_dma_segment_t *segs;
971 if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS)
972 segments = cache_segments;
974 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments,
975 M_DEVBUF, M_WAITOK | M_ZERO);
979 * Follow old semantics. Once all of the callers are fixed,
980 * we should get rid of these internal flag "adjustment".
982 flags &= ~BUS_DMA_WAITOK;
983 flags |= BUS_DMA_NOWAIT;
985 resid = (bus_size_t)uio->uio_resid;
989 nsegs_left = dmat->nsegments;
991 if (uio->uio_segflg == UIO_USERSPACE) {
995 KASSERT(td != NULL && td->td_proc != NULL,
996 ("bus_dmamap_load_uio: USERSPACE but no proc"));
997 pmap = vmspace_pmap(td->td_proc->p_vmspace);
1006 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
1008 * Now at the first iovec to load. Load each iovec
1009 * until we have exhausted the residual count.
1012 resid < iov[i].iov_len ? resid : iov[i].iov_len;
1013 caddr_t addr = (caddr_t) iov[i].iov_base;
1015 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
1017 pmap, flags, &lastaddr, &nsegs, first);
1022 nsegs_left -= nsegs;
1028 * Minimum one DMA segment, even if 0-length buffer.
1030 if (nsegs_left == dmat->nsegments)
1034 /* force "no valid mappings" in callback */
1035 callback(callback_arg, segments, 0,
1038 callback(callback_arg, segments, dmat->nsegments - nsegs_left,
1039 (bus_size_t)uio->uio_resid, error);
1041 if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS)
1042 kfree(segments, M_DEVBUF);
1047 * Release the mapping held by map.
1050 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1052 struct bounce_page *bpage;
1054 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1055 STAILQ_REMOVE_HEAD(&map->bpages, links);
1056 free_bounce_page(dmat, bpage);
1061 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1063 struct bounce_page *bpage;
1065 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1067 * Handle data bouncing. We might also
1068 * want to add support for invalidating
1069 * the caches on broken hardware
1072 case BUS_DMASYNC_PREWRITE:
1073 while (bpage != NULL) {
1074 bcopy((void *)bpage->datavaddr,
1075 (void *)bpage->vaddr,
1077 bpage = STAILQ_NEXT(bpage, links);
1079 dmat->bounce_zone->total_bounced++;
1082 case BUS_DMASYNC_POSTREAD:
1083 while (bpage != NULL) {
1084 bcopy((void *)bpage->vaddr,
1085 (void *)bpage->datavaddr,
1087 bpage = STAILQ_NEXT(bpage, links);
1089 dmat->bounce_zone->total_bounced++;
1092 case BUS_DMASYNC_PREREAD:
1093 case BUS_DMASYNC_POSTWRITE:
1101 alloc_bounce_zone(bus_dma_tag_t dmat)
1103 struct bounce_zone *bz, *new_bz;
1105 KASSERT(dmat->bounce_zone == NULL,
1106 ("bounce zone was already assigned"));
1108 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1110 lwkt_gettoken(&bounce_zone_tok);
1112 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1114 * For shared bounce zone, check to see
1115 * if we already have a suitable zone
1117 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1118 if (dmat->alignment <= bz->alignment &&
1119 dmat->lowaddr >= bz->lowaddr) {
1120 lwkt_reltoken(&bounce_zone_tok);
1122 dmat->bounce_zone = bz;
1123 kfree(new_bz, M_DEVBUF);
1131 spin_init(&bz->spin);
1133 STAILQ_INIT(&bz->bounce_page_list);
1134 STAILQ_INIT(&bz->bounce_map_waitinglist);
1135 bz->free_bpages = 0;
1136 bz->reserved_bpages = 0;
1137 bz->active_bpages = 0;
1138 bz->lowaddr = dmat->lowaddr;
1139 bz->alignment = round_page(dmat->alignment);
1140 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1142 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1143 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1145 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1147 ksnprintf(bz->zoneid, 8, "zone%d", busdma_priv_zonecount);
1148 busdma_priv_zonecount--;
1151 lwkt_reltoken(&bounce_zone_tok);
1153 dmat->bounce_zone = bz;
1155 sysctl_ctx_init(&bz->sysctl_ctx);
1156 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1157 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1159 if (bz->sysctl_tree == NULL) {
1160 sysctl_ctx_free(&bz->sysctl_ctx);
1161 return 0; /* XXX error code? */
1164 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1165 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1166 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1167 "Total bounce pages");
1168 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1169 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1170 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1171 "Free bounce pages");
1172 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1173 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1174 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1175 "Reserved bounce pages");
1176 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1177 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1178 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1179 "Active bounce pages");
1180 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1181 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1182 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1183 "Total bounce requests");
1184 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1185 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1186 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1187 "Total bounce requests that were deferred");
1188 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1189 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1190 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1191 "Total bounce page reservations that were failed");
1192 SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1193 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1194 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1195 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1196 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1197 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1203 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1205 struct bounce_zone *bz = dmat->bounce_zone;
1206 int count = 0, mflags;
1208 if (flags & BUS_DMA_NOWAIT)
1213 while (numpages > 0) {
1214 struct bounce_page *bpage;
1216 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1218 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1222 if (bpage->vaddr == 0) {
1223 kfree(bpage, M_DEVBUF);
1226 bpage->busaddr = pmap_kextract(bpage->vaddr);
1229 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1230 total_bounce_pages++;
1242 free_bounce_pages_all(bus_dma_tag_t dmat)
1244 struct bounce_zone *bz = dmat->bounce_zone;
1245 struct bounce_page *bpage;
1249 while ((bpage = STAILQ_FIRST(&bz->bounce_page_list)) != NULL) {
1250 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1252 KKASSERT(total_bounce_pages > 0);
1253 total_bounce_pages--;
1255 KKASSERT(bz->total_bpages > 0);
1258 KKASSERT(bz->free_bpages > 0);
1262 contigfree((void *)bpage->vaddr, PAGE_SIZE, M_DEVBUF);
1263 kfree(bpage, M_DEVBUF);
1266 if (bz->total_bpages) {
1267 kprintf("#%d bounce pages are still in use\n",
1269 print_backtrace(-1);
1276 free_bounce_zone(bus_dma_tag_t dmat)
1278 struct bounce_zone *bz = dmat->bounce_zone;
1283 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0)
1286 free_bounce_pages_all(dmat);
1287 dmat->bounce_zone = NULL;
1289 if (bz->sysctl_tree != NULL)
1290 sysctl_ctx_free(&bz->sysctl_ctx);
1291 kfree(bz, M_DEVBUF);
1294 /* Assume caller holds bounce zone spinlock */
1296 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1298 struct bounce_zone *bz = dmat->bounce_zone;
1301 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1302 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1303 bz->reserve_failed++;
1304 return (map->pagesneeded - (map->pagesreserved + pages));
1307 bz->free_bpages -= pages;
1309 bz->reserved_bpages += pages;
1310 KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1312 map->pagesreserved += pages;
1313 pages = map->pagesneeded - map->pagesreserved;
1319 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1321 struct bounce_zone *bz = dmat->bounce_zone;
1322 int reserved = map->pagesreserved;
1323 bus_dmamap_t wait_map;
1325 map->pagesreserved = 0;
1326 map->pagesneeded = 0;
1333 bz->free_bpages += reserved;
1334 KKASSERT(bz->free_bpages <= bz->total_bpages);
1336 KKASSERT(bz->reserved_bpages >= reserved);
1337 bz->reserved_bpages -= reserved;
1339 wait_map = get_map_waiting(dmat);
1343 if (wait_map != NULL)
1344 add_map_callback(map);
1348 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1351 struct bounce_zone *bz = dmat->bounce_zone;
1352 struct bounce_page *bpage;
1354 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1357 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1358 map->pagesreserved--;
1362 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1363 KASSERT(bpage != NULL, ("free page list is empty"));
1364 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1366 KKASSERT(bz->reserved_bpages > 0);
1367 bz->reserved_bpages--;
1369 bz->active_bpages++;
1370 KKASSERT(bz->active_bpages <= bz->total_bpages);
1374 bpage->datavaddr = vaddr;
1375 bpage->datacount = size;
1376 STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1377 return bpage->busaddr;
1381 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1383 struct bounce_zone *bz = dmat->bounce_zone;
1386 bpage->datavaddr = 0;
1387 bpage->datacount = 0;
1391 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1394 KKASSERT(bz->free_bpages <= bz->total_bpages);
1396 KKASSERT(bz->active_bpages > 0);
1397 bz->active_bpages--;
1399 map = get_map_waiting(dmat);
1404 add_map_callback(map);
1407 /* Assume caller holds bounce zone spinlock */
1409 get_map_waiting(bus_dma_tag_t dmat)
1411 struct bounce_zone *bz = dmat->bounce_zone;
1414 map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1416 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1417 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1418 bz->total_deferred++;
1427 add_map_callback(bus_dmamap_t map)
1429 spin_lock(&bounce_map_list_spin);
1430 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1431 busdma_swi_pending = 1;
1433 spin_unlock(&bounce_map_list_spin);
1441 spin_lock(&bounce_map_list_spin);
1442 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1443 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1444 spin_unlock(&bounce_map_list_spin);
1445 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1446 map->callback, map->callback_arg, /*flags*/0);
1447 spin_lock(&bounce_map_list_spin);
1449 spin_unlock(&bounce_map_list_spin);