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/thread2.h>
36 #include <sys/bus_dma.h>
37 #include <sys/kernel.h>
38 #include <sys/sysctl.h>
40 #include <sys/spinlock2.h>
43 #include <vm/vm_page.h>
45 /* XXX needed for to access pmap to convert per-proc virtual to physical */
48 #include <vm/vm_map.h>
50 #include <machine/md_var.h>
52 #define MAX_BPAGES 1024
55 * 16 x N declared on stack.
57 #define BUS_DMA_CACHE_SEGMENTS 8
68 bus_dma_filter_t *filter;
76 bus_dma_segment_t *segments;
77 struct bounce_zone *bounce_zone;
86 * bus_dma_tag private flags
88 #define BUS_DMA_BOUNCE_ALIGN BUS_DMA_BUS2
89 #define BUS_DMA_BOUNCE_LOWADDR BUS_DMA_BUS3
90 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
92 #define BUS_DMA_COULD_BOUNCE (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
94 #define BUS_DMAMEM_KMALLOC(dmat) \
95 ((dmat)->maxsize <= PAGE_SIZE && \
96 (dmat)->alignment <= PAGE_SIZE && \
97 (dmat)->lowaddr >= ptoa(Maxmem))
100 vm_offset_t vaddr; /* kva of bounce buffer */
101 bus_addr_t busaddr; /* Physical address */
102 vm_offset_t datavaddr; /* kva of client data */
103 bus_size_t datacount; /* client data count */
104 STAILQ_ENTRY(bounce_page) links;
108 STAILQ_ENTRY(bounce_zone) links;
109 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
110 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
112 struct spinlock spin;
123 bus_size_t alignment;
127 struct sysctl_ctx_list sysctl_ctx;
128 struct sysctl_oid *sysctl_tree;
132 #define BZ_LOCK(bz) spin_lock_wr(&(bz)->spin)
133 #define BZ_UNLOCK(bz) spin_unlock_wr(&(bz)->spin)
135 #define BZ_LOCK(bz) crit_enter()
136 #define BZ_UNLOCK(bz) crit_exit()
139 static struct lwkt_token bounce_zone_tok =
140 LWKT_TOKEN_INITIALIZER(bounce_zone_tok);
141 static int busdma_zonecount;
142 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
143 STAILQ_HEAD_INITIALIZER(bounce_zone_list);
145 int busdma_swi_pending;
146 static int total_bounce_pages;
147 static int max_bounce_pages = MAX_BPAGES;
148 static int bounce_alignment = 1; /* XXX temporary */
150 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
151 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
154 struct bp_list bpages;
158 void *buf; /* unmapped buffer pointer */
159 bus_size_t buflen; /* unmapped buffer length */
160 bus_dmamap_callback_t *callback;
162 STAILQ_ENTRY(bus_dmamap) links;
165 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
166 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
168 static struct bus_dmamap nobounce_dmamap;
170 static int alloc_bounce_zone(bus_dma_tag_t);
171 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int);
172 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
173 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
174 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
175 vm_offset_t, bus_size_t);
176 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
178 static bus_dmamap_t get_map_waiting(bus_dma_tag_t);
179 static void add_map_callback(bus_dmamap_t);
181 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
182 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
183 0, "Total bounce pages");
184 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
185 0, "Max bounce pages per bounce zone");
186 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
187 &bounce_alignment, 0, "Obey alignment constraint");
190 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
196 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
197 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
198 && (dmat->filter == NULL ||
199 dmat->filter(dmat->filterarg, paddr) != 0))
203 } while (retval == 0 && dmat != NULL);
209 bus_dma_tag_lock(bus_dma_tag_t tag, bus_dma_segment_t *cache)
211 if (tag->nsegments <= BUS_DMA_CACHE_SEGMENTS)
214 spin_lock_wr(&tag->spin);
216 return(tag->segments);
221 bus_dma_tag_unlock(bus_dma_tag_t tag)
224 if (tag->nsegments > BUS_DMA_CACHE_SEGMENTS)
225 spin_unlock_wr(&tag->spin);
230 * Allocate a device specific dma_tag.
233 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
234 bus_size_t boundary, bus_addr_t lowaddr,
235 bus_addr_t highaddr, bus_dma_filter_t *filter,
236 void *filterarg, bus_size_t maxsize, int nsegments,
237 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
239 bus_dma_tag_t newtag;
248 if (alignment & (alignment - 1))
249 panic("alignment must be power of 2\n");
252 if (boundary & (boundary - 1))
253 panic("boundary must be power of 2\n");
254 if (boundary < maxsegsz) {
255 kprintf("boundary < maxsegsz:\n");
261 /* Return a NULL tag on failure */
264 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT | M_ZERO);
267 spin_init(&newtag->spin);
269 newtag->parent = parent;
270 newtag->alignment = alignment;
271 newtag->boundary = boundary;
272 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
273 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
274 newtag->filter = filter;
275 newtag->filterarg = filterarg;
276 newtag->maxsize = maxsize;
277 newtag->nsegments = nsegments;
278 newtag->maxsegsz = maxsegsz;
279 newtag->flags = flags;
280 newtag->ref_count = 1; /* Count ourself */
281 newtag->map_count = 0;
282 newtag->segments = NULL;
283 newtag->bounce_zone = NULL;
285 /* Take into account any restrictions imposed by our parent tag */
286 if (parent != NULL) {
287 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
288 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
290 if (newtag->boundary == 0) {
291 newtag->boundary = parent->boundary;
292 } else if (parent->boundary != 0) {
293 newtag->boundary = MIN(parent->boundary,
298 newtag->alignment = MAX(parent->alignment, newtag->alignment);
301 if (newtag->filter == NULL) {
303 * Short circuit looking at our parent directly
304 * since we have encapsulated all of its information
306 newtag->filter = parent->filter;
307 newtag->filterarg = parent->filterarg;
308 newtag->parent = parent->parent;
310 if (newtag->parent != NULL)
314 if (newtag->lowaddr < ptoa(Maxmem))
315 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
316 if (bounce_alignment && newtag->alignment > 1 &&
317 !(newtag->flags & BUS_DMA_ALIGNED))
318 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
320 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
321 (flags & BUS_DMA_ALLOCNOW) != 0) {
322 struct bounce_zone *bz;
326 error = alloc_bounce_zone(newtag);
329 bz = newtag->bounce_zone;
331 if (ptoa(bz->total_bpages) < maxsize) {
334 if (flags & BUS_DMA_ONEBPAGE) {
337 pages = atop(round_page(maxsize)) -
339 pages = MAX(pages, 1);
342 /* Add pages to our bounce pool */
343 if (alloc_bounce_pages(newtag, pages, flags) < pages)
346 /* Performed initial allocation */
347 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
352 kfree(newtag, M_DEVBUF);
359 bus_dma_tag_destroy(bus_dma_tag_t dmat)
362 if (dmat->map_count != 0)
365 while (dmat != NULL) {
366 bus_dma_tag_t parent;
368 parent = dmat->parent;
370 if (dmat->ref_count == 0) {
371 if (dmat->segments != NULL)
372 kfree(dmat->segments, M_DEVBUF);
373 kfree(dmat, M_DEVBUF);
375 * Last reference count, so
376 * release our reference
377 * count on our parent.
388 bus_dma_tag_getmaxsize(bus_dma_tag_t tag)
390 return(tag->maxsize);
394 * Allocate a handle for mapping from kva/uva/physical
395 * address space into bus device space.
398 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
404 if (dmat->segments == NULL) {
405 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
406 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
407 dmat->nsegments, M_DEVBUF, M_INTWAIT);
410 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
411 struct bounce_zone *bz;
416 if (dmat->bounce_zone == NULL) {
417 error = alloc_bounce_zone(dmat);
421 bz = dmat->bounce_zone;
423 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
425 /* Initialize the new map */
426 STAILQ_INIT(&((*mapp)->bpages));
429 * Attempt to add pages to our pool on a per-instance
430 * basis up to a sane limit.
432 if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
433 maxpages = max_bounce_pages;
435 maxpages = MIN(max_bounce_pages,
436 Maxmem - atop(dmat->lowaddr));
438 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
439 || (dmat->map_count > 0
440 && bz->total_bpages < maxpages)) {
443 if (flags & BUS_DMA_ONEBPAGE) {
446 pages = atop(round_page(dmat->maxsize));
447 pages = MIN(maxpages - bz->total_bpages, pages);
448 pages = MAX(pages, 1);
450 if (alloc_bounce_pages(dmat, pages, flags) < pages)
453 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
455 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
469 * Destroy a handle for mapping from kva/uva/physical
470 * address space into bus device space.
473 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
476 if (STAILQ_FIRST(&map->bpages) != NULL)
478 kfree(map, M_DEVBUF);
484 static __inline bus_size_t
485 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
487 bus_size_t maxsize = 0;
488 uintptr_t vaddr = (uintptr_t)vaddr0;
490 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
491 kprintf("boundary check failed\n");
493 print_backtrace(); /* XXX panic */
494 maxsize = dmat->maxsize;
496 if (vaddr & (dmat->alignment - 1)) {
497 kprintf("alignment check failed\n");
499 print_backtrace(); /* XXX panic */
500 if (dmat->maxsize < dmat->alignment)
501 maxsize = dmat->alignment;
503 maxsize = dmat->maxsize;
509 * Allocate a piece of memory that can be efficiently mapped into
510 * bus device space based on the constraints lited in the dma tag.
512 * mapp is degenerate. By definition this allocation should not require
513 * bounce buffers so do not allocate a dma map.
516 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
521 /* If we succeed, no mapping/bouncing will be required */
524 if (dmat->segments == NULL) {
525 KKASSERT(dmat->nsegments < 16384);
526 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
527 dmat->nsegments, M_DEVBUF, M_INTWAIT);
530 if (flags & BUS_DMA_NOWAIT)
534 if (flags & BUS_DMA_ZERO)
537 if (BUS_DMAMEM_KMALLOC(dmat)) {
540 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
544 * Check whether the allocation
545 * - crossed a page boundary
547 * Retry with power-of-2 alignment in the above cases.
549 maxsize = check_kmalloc(dmat, *vaddr, 0);
553 kfree(*vaddr, M_DEVBUF);
554 /* XXX check for overflow? */
555 for (size = 1; size <= maxsize; size <<= 1)
557 *vaddr = kmalloc(size, M_DEVBUF, mflags);
558 check_kmalloc(dmat, *vaddr, 1);
562 * XXX Use Contigmalloc until it is merged into this facility
563 * and handles multi-seg allocations. Nobody is doing
564 * multi-seg allocations yet though.
566 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
567 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
575 * Free a piece of memory and it's allociated dmamap, that was allocated
576 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
579 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
582 * dmamem does not need to be bounced, so the map should be
586 panic("bus_dmamem_free: Invalid map freed\n");
587 if (BUS_DMAMEM_KMALLOC(dmat))
588 kfree(vaddr, M_DEVBUF);
590 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
593 static __inline vm_paddr_t
594 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
597 return pmap_extract(pmap, vaddr);
599 return pmap_kextract(vaddr);
603 * Utility function to load a linear buffer. lastaddrp holds state
604 * between invocations (for multiple-buffer loads). segp contains
605 * the segment following the starting one on entrace, and the ending
606 * segment on exit. first indicates if this is the first invocation
610 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
612 void *buf, bus_size_t buflen,
613 bus_dma_segment_t *segments,
617 vm_paddr_t *lastpaddrp,
622 vm_paddr_t paddr, nextpaddr;
623 bus_dma_segment_t *sg;
628 map = &nobounce_dmamap;
631 if (dmat->flags & BUS_DMA_ALIGNED)
632 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
636 * If we are being called during a callback, pagesneeded will
637 * be non-zero, so we can avoid doing the work twice.
639 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
640 map != &nobounce_dmamap && map->pagesneeded == 0) {
641 vm_offset_t vendaddr;
644 * Count the number of bounce pages
645 * needed in order to complete this transfer
647 vaddr = (vm_offset_t)buf;
648 vendaddr = (vm_offset_t)buf + buflen;
650 while (vaddr < vendaddr) {
651 paddr = _bus_dma_extract(pmap, vaddr);
652 if (run_filter(dmat, paddr) != 0)
654 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
658 /* Reserve Necessary Bounce Pages */
659 if (map->pagesneeded != 0) {
660 struct bounce_zone *bz;
662 bz = dmat->bounce_zone;
664 if (flags & BUS_DMA_NOWAIT) {
665 if (reserve_bounce_pages(dmat, map, 0) != 0) {
671 if (reserve_bounce_pages(dmat, map, 1) != 0) {
672 /* Queue us for resources */
675 map->buflen = buflen;
678 &dmat->bounce_zone->bounce_map_waitinglist,
682 return (EINPROGRESS);
688 KKASSERT(*segp >= 1 && *segp <= nsegments);
690 sg = &segments[seg - 1];
692 vaddr = (vm_offset_t)buf;
693 nextpaddr = *lastpaddrp;
694 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
696 /* force at least one segment */
703 paddr = _bus_dma_extract(pmap, vaddr);
704 size = PAGE_SIZE - (paddr & PAGE_MASK);
707 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
709 * note: this paddr has the same in-page offset
710 * as vaddr and thus the paddr above, so the
711 * size does not have to be recalculated
713 paddr = add_bounce_page(dmat, map, vaddr, size);
717 * Fill in the bus_dma_segment
723 } else if (paddr == nextpaddr) {
733 nextpaddr = paddr + size;
736 * Handle maxsegsz and boundary issues with a nested loop
742 * Limit to the boundary and maximum segment size
744 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
745 tmpsize = dmat->boundary -
746 (sg->ds_addr & ~bmask);
747 if (tmpsize > dmat->maxsegsz)
748 tmpsize = dmat->maxsegsz;
749 KKASSERT(tmpsize < sg->ds_len);
750 } else if (sg->ds_len > dmat->maxsegsz) {
751 tmpsize = dmat->maxsegsz;
757 * Futz, split the data into a new segment.
759 if (seg >= nsegments)
761 sg[1].ds_len = sg[0].ds_len - tmpsize;
762 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
763 sg[0].ds_len = tmpsize;
773 } while (buflen > 0);
779 *lastpaddrp = nextpaddr;
782 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
783 map != &nobounce_dmamap) {
784 _bus_dmamap_unload(dmat, map);
785 return_bounce_pages(dmat, map);
791 * Map the buffer buf into bus space using the dmamap map.
794 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
795 bus_size_t buflen, bus_dmamap_callback_t *callback,
796 void *callback_arg, int flags)
798 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
799 bus_dma_segment_t *segments;
800 vm_paddr_t lastaddr = 0;
801 int error, nsegs = 1;
806 * Follow old semantics. Once all of the callers are fixed,
807 * we should get rid of these internal flag "adjustment".
809 flags &= ~BUS_DMA_NOWAIT;
810 flags |= BUS_DMA_WAITOK;
812 map->callback = callback;
813 map->callback_arg = callback_arg;
816 segments = bus_dma_tag_lock(dmat, cache_segments);
817 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
818 segments, dmat->nsegments,
819 NULL, flags, &lastaddr, &nsegs, 1);
820 if (error == EINPROGRESS) {
821 bus_dma_tag_unlock(dmat);
824 callback(callback_arg, segments, nsegs, error);
825 bus_dma_tag_unlock(dmat);
830 * Like _bus_dmamap_load(), but for mbufs.
833 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
835 bus_dmamap_callback2_t *callback, void *callback_arg,
838 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
839 bus_dma_segment_t *segments;
844 * Follow old semantics. Once all of the callers are fixed,
845 * we should get rid of these internal flag "adjustment".
847 flags &= ~BUS_DMA_WAITOK;
848 flags |= BUS_DMA_NOWAIT;
850 segments = bus_dma_tag_lock(dmat, cache_segments);
851 error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
852 segments, dmat->nsegments, &nsegs, flags);
854 /* force "no valid mappings" in callback */
855 callback(callback_arg, segments, 0,
858 callback(callback_arg, segments, nsegs,
859 m0->m_pkthdr.len, error);
861 bus_dma_tag_unlock(dmat);
866 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
868 bus_dma_segment_t *segs, int maxsegs,
869 int *nsegs, int flags)
875 KASSERT(maxsegs >= 1, ("invalid maxsegs %d\n", maxsegs));
876 KASSERT(maxsegs <= dmat->nsegments,
877 ("%d too many segments, dmat only support %d segments\n",
878 maxsegs, dmat->nsegments));
879 KASSERT(flags & BUS_DMA_NOWAIT,
880 ("only BUS_DMA_NOWAIT is supported\n"));
882 if (m0->m_pkthdr.len <= dmat->maxsize) {
884 vm_paddr_t lastaddr = 0;
889 for (m = m0; m != NULL && error == 0; m = m->m_next) {
893 error = _bus_dmamap_load_buffer(dmat, map,
896 NULL, flags, &lastaddr,
898 if (error == ENOMEM && !first) {
900 * Out of bounce pages due to too many
901 * fragments in the mbuf chain; return
910 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
916 KKASSERT(error != EINPROGRESS);
921 * Like _bus_dmamap_load(), but for uios.
924 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
926 bus_dmamap_callback2_t *callback, void *callback_arg,
930 int nsegs, error, first, i;
934 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
935 bus_dma_segment_t *segments;
936 bus_dma_segment_t *segs;
939 if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS)
940 segments = cache_segments;
942 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments,
943 M_DEVBUF, M_WAITOK | M_ZERO);
947 * Follow old semantics. Once all of the callers are fixed,
948 * we should get rid of these internal flag "adjustment".
950 flags &= ~BUS_DMA_WAITOK;
951 flags |= BUS_DMA_NOWAIT;
953 resid = uio->uio_resid;
957 nsegs_left = dmat->nsegments;
959 if (uio->uio_segflg == UIO_USERSPACE) {
963 KASSERT(td != NULL && td->td_proc != NULL,
964 ("bus_dmamap_load_uio: USERSPACE but no proc"));
965 pmap = vmspace_pmap(td->td_proc->p_vmspace);
974 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
976 * Now at the first iovec to load. Load each iovec
977 * until we have exhausted the residual count.
980 resid < iov[i].iov_len ? resid : iov[i].iov_len;
981 caddr_t addr = (caddr_t) iov[i].iov_base;
983 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
985 pmap, flags, &lastaddr, &nsegs, first);
996 * Minimum one DMA segment, even if 0-length buffer.
998 if (nsegs_left == dmat->nsegments)
1002 /* force "no valid mappings" in callback */
1003 callback(callback_arg, segments, 0,
1006 callback(callback_arg, segments, dmat->nsegments - nsegs_left,
1007 uio->uio_resid, error);
1009 if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS)
1010 kfree(segments, M_DEVBUF);
1015 * Release the mapping held by map.
1018 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1020 struct bounce_page *bpage;
1022 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1023 STAILQ_REMOVE_HEAD(&map->bpages, links);
1024 free_bounce_page(dmat, bpage);
1029 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1031 struct bounce_page *bpage;
1033 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1035 * Handle data bouncing. We might also
1036 * want to add support for invalidating
1037 * the caches on broken hardware
1040 case BUS_DMASYNC_PREWRITE:
1041 while (bpage != NULL) {
1042 bcopy((void *)bpage->datavaddr,
1043 (void *)bpage->vaddr,
1045 bpage = STAILQ_NEXT(bpage, links);
1047 dmat->bounce_zone->total_bounced++;
1050 case BUS_DMASYNC_POSTREAD:
1051 while (bpage != NULL) {
1052 bcopy((void *)bpage->vaddr,
1053 (void *)bpage->datavaddr,
1055 bpage = STAILQ_NEXT(bpage, links);
1057 dmat->bounce_zone->total_bounced++;
1060 case BUS_DMASYNC_PREREAD:
1061 case BUS_DMASYNC_POSTWRITE:
1069 alloc_bounce_zone(bus_dma_tag_t dmat)
1071 struct bounce_zone *bz, *new_bz;
1074 KASSERT(dmat->bounce_zone == NULL,
1075 ("bounce zone was already assigned\n"));
1077 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1079 lwkt_gettoken(&ref, &bounce_zone_tok);
1081 /* Check to see if we already have a suitable zone */
1082 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1083 if (dmat->alignment <= bz->alignment &&
1084 dmat->lowaddr >= bz->lowaddr) {
1085 lwkt_reltoken(&ref);
1087 dmat->bounce_zone = bz;
1088 kfree(new_bz, M_DEVBUF);
1095 spin_init(&bz->spin);
1097 STAILQ_INIT(&bz->bounce_page_list);
1098 STAILQ_INIT(&bz->bounce_map_waitinglist);
1099 bz->free_bpages = 0;
1100 bz->reserved_bpages = 0;
1101 bz->active_bpages = 0;
1102 bz->lowaddr = dmat->lowaddr;
1103 bz->alignment = round_page(dmat->alignment);
1104 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1106 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1107 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1109 lwkt_reltoken(&ref);
1111 dmat->bounce_zone = bz;
1113 sysctl_ctx_init(&bz->sysctl_ctx);
1114 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1115 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1117 if (bz->sysctl_tree == NULL) {
1118 sysctl_ctx_free(&bz->sysctl_ctx);
1119 return 0; /* XXX error code? */
1122 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1123 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1124 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1125 "Total bounce pages");
1126 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1127 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1128 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1129 "Free bounce pages");
1130 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1131 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1132 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1133 "Reserved bounce pages");
1134 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1135 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1136 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1137 "Active bounce pages");
1138 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1139 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1140 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1141 "Total bounce requests");
1142 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1143 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1144 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1145 "Total bounce requests that were deferred");
1146 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1147 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1148 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1149 "Total bounce page reservations that were failed");
1150 SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1151 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1152 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1153 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1154 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1155 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1161 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1163 struct bounce_zone *bz = dmat->bounce_zone;
1164 int count = 0, mflags;
1166 if (flags & BUS_DMA_NOWAIT)
1171 while (numpages > 0) {
1172 struct bounce_page *bpage;
1174 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1176 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1180 if (bpage->vaddr == 0) {
1181 kfree(bpage, M_DEVBUF);
1184 bpage->busaddr = pmap_kextract(bpage->vaddr);
1187 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1188 total_bounce_pages++;
1199 /* Assume caller holds bounce zone spinlock */
1201 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1203 struct bounce_zone *bz = dmat->bounce_zone;
1206 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1207 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1208 bz->reserve_failed++;
1209 return (map->pagesneeded - (map->pagesreserved + pages));
1212 bz->free_bpages -= pages;
1214 bz->reserved_bpages += pages;
1215 KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1217 map->pagesreserved += pages;
1218 pages = map->pagesneeded - map->pagesreserved;
1224 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1226 struct bounce_zone *bz = dmat->bounce_zone;
1227 int reserved = map->pagesreserved;
1228 bus_dmamap_t wait_map;
1230 map->pagesreserved = 0;
1231 map->pagesneeded = 0;
1238 bz->free_bpages += reserved;
1239 KKASSERT(bz->free_bpages <= bz->total_bpages);
1241 KKASSERT(bz->reserved_bpages >= reserved);
1242 bz->reserved_bpages -= reserved;
1244 wait_map = get_map_waiting(dmat);
1248 if (wait_map != NULL)
1249 add_map_callback(map);
1253 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1256 struct bounce_zone *bz = dmat->bounce_zone;
1257 struct bounce_page *bpage;
1259 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1262 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1263 map->pagesreserved--;
1267 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1268 KASSERT(bpage != NULL, ("free page list is empty"));
1269 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1271 KKASSERT(bz->reserved_bpages > 0);
1272 bz->reserved_bpages--;
1274 bz->active_bpages++;
1275 KKASSERT(bz->active_bpages <= bz->total_bpages);
1279 bpage->datavaddr = vaddr;
1280 bpage->datacount = size;
1281 STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1282 return bpage->busaddr;
1286 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1288 struct bounce_zone *bz = dmat->bounce_zone;
1291 bpage->datavaddr = 0;
1292 bpage->datacount = 0;
1296 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1299 KKASSERT(bz->free_bpages <= bz->total_bpages);
1301 KKASSERT(bz->active_bpages > 0);
1302 bz->active_bpages--;
1304 map = get_map_waiting(dmat);
1309 add_map_callback(map);
1312 /* Assume caller holds bounce zone spinlock */
1314 get_map_waiting(bus_dma_tag_t dmat)
1316 struct bounce_zone *bz = dmat->bounce_zone;
1319 map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1321 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1322 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1323 bz->total_deferred++;
1332 add_map_callback(bus_dmamap_t map)
1334 /* XXX callbacklist is not MPSAFE */
1337 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1338 busdma_swi_pending = 1;
1350 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1351 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1353 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1354 map->callback, map->callback_arg, /*flags*/0);