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_MP_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 int busdma_swi_pending;
148 static int total_bounce_pages;
149 static int max_bounce_pages = MAX_BPAGES;
150 static int bounce_alignment = 1; /* XXX temporary */
152 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
153 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
156 struct bp_list bpages;
160 void *buf; /* unmapped buffer pointer */
161 bus_size_t buflen; /* unmapped buffer length */
162 bus_dmamap_callback_t *callback;
164 STAILQ_ENTRY(bus_dmamap) links;
167 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
168 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
169 static struct spinlock bounce_map_list_spin =
170 SPINLOCK_INITIALIZER(&bounce_map_list_spin);
172 static struct bus_dmamap nobounce_dmamap;
174 static int alloc_bounce_zone(bus_dma_tag_t);
175 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int);
176 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
177 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
178 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
179 vm_offset_t, bus_size_t);
180 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
182 static bus_dmamap_t get_map_waiting(bus_dma_tag_t);
183 static void add_map_callback(bus_dmamap_t);
185 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
186 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
187 0, "Total bounce pages");
188 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
189 0, "Max bounce pages per bounce zone");
190 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
191 &bounce_alignment, 0, "Obey alignment constraint");
194 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
200 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
201 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
202 && (dmat->filter == NULL ||
203 dmat->filter(dmat->filterarg, paddr) != 0))
207 } while (retval == 0 && dmat != NULL);
213 bus_dma_tag_lock(bus_dma_tag_t tag, bus_dma_segment_t *cache)
215 if (tag->nsegments <= BUS_DMA_CACHE_SEGMENTS)
218 spin_lock(&tag->spin);
220 return(tag->segments);
225 bus_dma_tag_unlock(bus_dma_tag_t tag)
228 if (tag->nsegments > BUS_DMA_CACHE_SEGMENTS)
229 spin_unlock(&tag->spin);
234 * Allocate a device specific dma_tag.
237 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
238 bus_size_t boundary, bus_addr_t lowaddr,
239 bus_addr_t highaddr, bus_dma_filter_t *filter,
240 void *filterarg, bus_size_t maxsize, int nsegments,
241 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
243 bus_dma_tag_t newtag;
252 if (alignment & (alignment - 1))
253 panic("alignment must be power of 2\n");
256 if (boundary & (boundary - 1))
257 panic("boundary must be power of 2\n");
258 if (boundary < maxsegsz) {
259 kprintf("boundary < maxsegsz:\n");
265 /* Return a NULL tag on failure */
268 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT | M_ZERO);
271 spin_init(&newtag->spin);
273 newtag->parent = parent;
274 newtag->alignment = alignment;
275 newtag->boundary = boundary;
276 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
277 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
278 newtag->filter = filter;
279 newtag->filterarg = filterarg;
280 newtag->maxsize = maxsize;
281 newtag->nsegments = nsegments;
282 newtag->maxsegsz = maxsegsz;
283 newtag->flags = flags;
284 newtag->ref_count = 1; /* Count ourself */
285 newtag->map_count = 0;
286 newtag->segments = NULL;
287 newtag->bounce_zone = NULL;
289 /* Take into account any restrictions imposed by our parent tag */
290 if (parent != NULL) {
291 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
292 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
294 if (newtag->boundary == 0) {
295 newtag->boundary = parent->boundary;
296 } else if (parent->boundary != 0) {
297 newtag->boundary = MIN(parent->boundary,
302 newtag->alignment = MAX(parent->alignment, newtag->alignment);
305 if (newtag->filter == NULL) {
307 * Short circuit looking at our parent directly
308 * since we have encapsulated all of its information
310 newtag->filter = parent->filter;
311 newtag->filterarg = parent->filterarg;
312 newtag->parent = parent->parent;
314 if (newtag->parent != NULL)
318 if (newtag->lowaddr < ptoa(Maxmem))
319 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
320 if (bounce_alignment && newtag->alignment > 1 &&
321 !(newtag->flags & BUS_DMA_ALIGNED))
322 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
324 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
325 (flags & BUS_DMA_ALLOCNOW) != 0) {
326 struct bounce_zone *bz;
330 error = alloc_bounce_zone(newtag);
333 bz = newtag->bounce_zone;
335 if (ptoa(bz->total_bpages) < maxsize) {
338 if (flags & BUS_DMA_ONEBPAGE) {
341 pages = atop(round_page(maxsize)) -
343 pages = MAX(pages, 1);
346 /* Add pages to our bounce pool */
347 if (alloc_bounce_pages(newtag, pages, flags) < pages)
350 /* Performed initial allocation */
351 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
356 kfree(newtag, M_DEVBUF);
363 bus_dma_tag_destroy(bus_dma_tag_t dmat)
366 if (dmat->map_count != 0)
369 while (dmat != NULL) {
370 bus_dma_tag_t parent;
372 parent = dmat->parent;
374 if (dmat->ref_count == 0) {
375 if (dmat->segments != NULL)
376 kfree(dmat->segments, M_DEVBUF);
377 kfree(dmat, M_DEVBUF);
379 * Last reference count, so
380 * release our reference
381 * count on our parent.
392 bus_dma_tag_getmaxsize(bus_dma_tag_t tag)
394 return(tag->maxsize);
398 * Allocate a handle for mapping from kva/uva/physical
399 * address space into bus device space.
402 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
408 if (dmat->segments == NULL) {
409 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
410 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
411 dmat->nsegments, M_DEVBUF, M_INTWAIT);
414 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
415 struct bounce_zone *bz;
420 if (dmat->bounce_zone == NULL) {
421 error = alloc_bounce_zone(dmat);
425 bz = dmat->bounce_zone;
427 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
429 /* Initialize the new map */
430 STAILQ_INIT(&((*mapp)->bpages));
433 * Attempt to add pages to our pool on a per-instance
434 * basis up to a sane limit.
436 if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
437 maxpages = max_bounce_pages;
439 maxpages = MIN(max_bounce_pages,
440 Maxmem - atop(dmat->lowaddr));
442 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
443 || (dmat->map_count > 0
444 && bz->total_bpages < maxpages)) {
447 if (flags & BUS_DMA_ONEBPAGE) {
450 pages = atop(round_page(dmat->maxsize));
451 pages = MIN(maxpages - bz->total_bpages, pages);
452 pages = MAX(pages, 1);
454 if (alloc_bounce_pages(dmat, pages, flags) < pages)
457 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
459 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
473 * Destroy a handle for mapping from kva/uva/physical
474 * address space into bus device space.
477 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
480 if (STAILQ_FIRST(&map->bpages) != NULL)
482 kfree(map, M_DEVBUF);
488 static __inline bus_size_t
489 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
491 bus_size_t maxsize = 0;
492 uintptr_t vaddr = (uintptr_t)vaddr0;
494 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
495 if (verify || bootverbose)
496 kprintf("boundary check failed\n");
498 print_backtrace(-1); /* XXX panic */
499 maxsize = dmat->maxsize;
501 if (vaddr & (dmat->alignment - 1)) {
502 if (verify || bootverbose)
503 kprintf("alignment check failed\n");
505 print_backtrace(-1); /* XXX panic */
506 if (dmat->maxsize < dmat->alignment)
507 maxsize = dmat->alignment;
509 maxsize = dmat->maxsize;
515 * Allocate a piece of memory that can be efficiently mapped into
516 * bus device space based on the constraints lited in the dma tag.
518 * mapp is degenerate. By definition this allocation should not require
519 * bounce buffers so do not allocate a dma map.
522 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
527 /* If we succeed, no mapping/bouncing will be required */
530 if (dmat->segments == NULL) {
531 KKASSERT(dmat->nsegments < 16384);
532 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
533 dmat->nsegments, M_DEVBUF, M_INTWAIT);
536 if (flags & BUS_DMA_NOWAIT)
540 if (flags & BUS_DMA_ZERO)
543 if (BUS_DMAMEM_KMALLOC(dmat)) {
546 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
550 * Check whether the allocation
551 * - crossed a page boundary
553 * Retry with power-of-2 alignment in the above cases.
555 maxsize = check_kmalloc(dmat, *vaddr, 0);
559 kfree(*vaddr, M_DEVBUF);
560 /* XXX check for overflow? */
561 for (size = 1; size <= maxsize; size <<= 1)
563 *vaddr = kmalloc(size, M_DEVBUF, mflags);
564 check_kmalloc(dmat, *vaddr, 1);
568 * XXX Use Contigmalloc until it is merged into this facility
569 * and handles multi-seg allocations. Nobody is doing
570 * multi-seg allocations yet though.
572 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
573 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
581 * Free a piece of memory and it's allociated dmamap, that was allocated
582 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
585 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
588 * dmamem does not need to be bounced, so the map should be
592 panic("bus_dmamem_free: Invalid map freed\n");
593 if (BUS_DMAMEM_KMALLOC(dmat))
594 kfree(vaddr, M_DEVBUF);
596 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
599 static __inline vm_paddr_t
600 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
603 return pmap_extract(pmap, vaddr);
605 return pmap_kextract(vaddr);
609 * Utility function to load a linear buffer. lastaddrp holds state
610 * between invocations (for multiple-buffer loads). segp contains
611 * the segment following the starting one on entrace, and the ending
612 * segment on exit. first indicates if this is the first invocation
616 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
618 void *buf, bus_size_t buflen,
619 bus_dma_segment_t *segments,
623 vm_paddr_t *lastpaddrp,
628 vm_paddr_t paddr, nextpaddr;
629 bus_dma_segment_t *sg;
634 map = &nobounce_dmamap;
637 if (dmat->flags & BUS_DMA_ALIGNED)
638 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
642 * If we are being called during a callback, pagesneeded will
643 * be non-zero, so we can avoid doing the work twice.
645 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
646 map != &nobounce_dmamap && map->pagesneeded == 0) {
647 vm_offset_t vendaddr;
650 * Count the number of bounce pages
651 * needed in order to complete this transfer
653 vaddr = (vm_offset_t)buf;
654 vendaddr = (vm_offset_t)buf + buflen;
656 while (vaddr < vendaddr) {
657 paddr = _bus_dma_extract(pmap, vaddr);
658 if (run_filter(dmat, paddr) != 0)
660 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
664 /* Reserve Necessary Bounce Pages */
665 if (map->pagesneeded != 0) {
666 struct bounce_zone *bz;
668 bz = dmat->bounce_zone;
670 if (flags & BUS_DMA_NOWAIT) {
671 if (reserve_bounce_pages(dmat, map, 0) != 0) {
677 if (reserve_bounce_pages(dmat, map, 1) != 0) {
678 /* Queue us for resources */
681 map->buflen = buflen;
684 &dmat->bounce_zone->bounce_map_waitinglist,
688 return (EINPROGRESS);
694 KKASSERT(*segp >= 1 && *segp <= nsegments);
696 sg = &segments[seg - 1];
698 vaddr = (vm_offset_t)buf;
699 nextpaddr = *lastpaddrp;
700 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
702 /* force at least one segment */
709 paddr = _bus_dma_extract(pmap, vaddr);
710 size = PAGE_SIZE - (paddr & PAGE_MASK);
713 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
715 * note: this paddr has the same in-page offset
716 * as vaddr and thus the paddr above, so the
717 * size does not have to be recalculated
719 paddr = add_bounce_page(dmat, map, vaddr, size);
723 * Fill in the bus_dma_segment
729 } else if (paddr == nextpaddr) {
739 nextpaddr = paddr + size;
742 * Handle maxsegsz and boundary issues with a nested loop
748 * Limit to the boundary and maximum segment size
750 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
751 tmpsize = dmat->boundary -
752 (sg->ds_addr & ~bmask);
753 if (tmpsize > dmat->maxsegsz)
754 tmpsize = dmat->maxsegsz;
755 KKASSERT(tmpsize < sg->ds_len);
756 } else if (sg->ds_len > dmat->maxsegsz) {
757 tmpsize = dmat->maxsegsz;
763 * Futz, split the data into a new segment.
765 if (seg >= nsegments)
767 sg[1].ds_len = sg[0].ds_len - tmpsize;
768 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
769 sg[0].ds_len = tmpsize;
779 } while (buflen > 0);
785 *lastpaddrp = nextpaddr;
788 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
789 map != &nobounce_dmamap) {
790 _bus_dmamap_unload(dmat, map);
791 return_bounce_pages(dmat, map);
797 * Map the buffer buf into bus space using the dmamap map.
800 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
801 bus_size_t buflen, bus_dmamap_callback_t *callback,
802 void *callback_arg, int flags)
804 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
805 bus_dma_segment_t *segments;
806 vm_paddr_t lastaddr = 0;
807 int error, nsegs = 1;
812 * Follow old semantics. Once all of the callers are fixed,
813 * we should get rid of these internal flag "adjustment".
815 flags &= ~BUS_DMA_NOWAIT;
816 flags |= BUS_DMA_WAITOK;
818 map->callback = callback;
819 map->callback_arg = callback_arg;
822 segments = bus_dma_tag_lock(dmat, cache_segments);
823 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
824 segments, dmat->nsegments,
825 NULL, flags, &lastaddr, &nsegs, 1);
826 if (error == EINPROGRESS) {
827 bus_dma_tag_unlock(dmat);
830 callback(callback_arg, segments, nsegs, error);
831 bus_dma_tag_unlock(dmat);
836 * Like _bus_dmamap_load(), but for mbufs.
839 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
841 bus_dmamap_callback2_t *callback, void *callback_arg,
844 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
845 bus_dma_segment_t *segments;
850 * Follow old semantics. Once all of the callers are fixed,
851 * we should get rid of these internal flag "adjustment".
853 flags &= ~BUS_DMA_WAITOK;
854 flags |= BUS_DMA_NOWAIT;
856 segments = bus_dma_tag_lock(dmat, cache_segments);
857 error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
858 segments, dmat->nsegments, &nsegs, flags);
860 /* force "no valid mappings" in callback */
861 callback(callback_arg, segments, 0,
864 callback(callback_arg, segments, nsegs,
865 m0->m_pkthdr.len, error);
867 bus_dma_tag_unlock(dmat);
872 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
874 bus_dma_segment_t *segs, int maxsegs,
875 int *nsegs, int flags)
881 KASSERT(maxsegs >= 1, ("invalid maxsegs %d\n", maxsegs));
882 KASSERT(maxsegs <= dmat->nsegments,
883 ("%d too many segments, dmat only support %d segments\n",
884 maxsegs, dmat->nsegments));
885 KASSERT(flags & BUS_DMA_NOWAIT,
886 ("only BUS_DMA_NOWAIT is supported\n"));
888 if (m0->m_pkthdr.len <= dmat->maxsize) {
890 vm_paddr_t lastaddr = 0;
895 for (m = m0; m != NULL && error == 0; m = m->m_next) {
899 error = _bus_dmamap_load_buffer(dmat, map,
902 NULL, flags, &lastaddr,
904 if (error == ENOMEM && !first) {
906 * Out of bounce pages due to too many
907 * fragments in the mbuf chain; return
916 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
922 KKASSERT(error != EINPROGRESS);
927 * Like _bus_dmamap_load(), but for uios.
930 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
932 bus_dmamap_callback2_t *callback, void *callback_arg,
936 int nsegs, error, first, i;
940 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
941 bus_dma_segment_t *segments;
942 bus_dma_segment_t *segs;
945 if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS)
946 segments = cache_segments;
948 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments,
949 M_DEVBUF, M_WAITOK | M_ZERO);
953 * Follow old semantics. Once all of the callers are fixed,
954 * we should get rid of these internal flag "adjustment".
956 flags &= ~BUS_DMA_WAITOK;
957 flags |= BUS_DMA_NOWAIT;
959 resid = (bus_size_t)uio->uio_resid;
963 nsegs_left = dmat->nsegments;
965 if (uio->uio_segflg == UIO_USERSPACE) {
969 KASSERT(td != NULL && td->td_proc != NULL,
970 ("bus_dmamap_load_uio: USERSPACE but no proc"));
971 pmap = vmspace_pmap(td->td_proc->p_vmspace);
980 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
982 * Now at the first iovec to load. Load each iovec
983 * until we have exhausted the residual count.
986 resid < iov[i].iov_len ? resid : iov[i].iov_len;
987 caddr_t addr = (caddr_t) iov[i].iov_base;
989 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
991 pmap, flags, &lastaddr, &nsegs, first);
1002 * Minimum one DMA segment, even if 0-length buffer.
1004 if (nsegs_left == dmat->nsegments)
1008 /* force "no valid mappings" in callback */
1009 callback(callback_arg, segments, 0,
1012 callback(callback_arg, segments, dmat->nsegments - nsegs_left,
1013 (bus_size_t)uio->uio_resid, error);
1015 if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS)
1016 kfree(segments, M_DEVBUF);
1021 * Release the mapping held by map.
1024 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1026 struct bounce_page *bpage;
1028 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1029 STAILQ_REMOVE_HEAD(&map->bpages, links);
1030 free_bounce_page(dmat, bpage);
1035 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1037 struct bounce_page *bpage;
1039 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1041 * Handle data bouncing. We might also
1042 * want to add support for invalidating
1043 * the caches on broken hardware
1046 case BUS_DMASYNC_PREWRITE:
1047 while (bpage != NULL) {
1048 bcopy((void *)bpage->datavaddr,
1049 (void *)bpage->vaddr,
1051 bpage = STAILQ_NEXT(bpage, links);
1053 dmat->bounce_zone->total_bounced++;
1056 case BUS_DMASYNC_POSTREAD:
1057 while (bpage != NULL) {
1058 bcopy((void *)bpage->vaddr,
1059 (void *)bpage->datavaddr,
1061 bpage = STAILQ_NEXT(bpage, links);
1063 dmat->bounce_zone->total_bounced++;
1066 case BUS_DMASYNC_PREREAD:
1067 case BUS_DMASYNC_POSTWRITE:
1075 alloc_bounce_zone(bus_dma_tag_t dmat)
1077 struct bounce_zone *bz, *new_bz;
1079 KASSERT(dmat->bounce_zone == NULL,
1080 ("bounce zone was already assigned\n"));
1082 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1084 lwkt_gettoken(&bounce_zone_tok);
1086 /* Check to see if we already have a suitable zone */
1087 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1088 if (dmat->alignment <= bz->alignment &&
1089 dmat->lowaddr >= bz->lowaddr) {
1090 lwkt_reltoken(&bounce_zone_tok);
1092 dmat->bounce_zone = bz;
1093 kfree(new_bz, M_DEVBUF);
1100 spin_init(&bz->spin);
1102 STAILQ_INIT(&bz->bounce_page_list);
1103 STAILQ_INIT(&bz->bounce_map_waitinglist);
1104 bz->free_bpages = 0;
1105 bz->reserved_bpages = 0;
1106 bz->active_bpages = 0;
1107 bz->lowaddr = dmat->lowaddr;
1108 bz->alignment = round_page(dmat->alignment);
1109 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1111 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1112 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1114 lwkt_reltoken(&bounce_zone_tok);
1116 dmat->bounce_zone = bz;
1118 sysctl_ctx_init(&bz->sysctl_ctx);
1119 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1120 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1122 if (bz->sysctl_tree == NULL) {
1123 sysctl_ctx_free(&bz->sysctl_ctx);
1124 return 0; /* XXX error code? */
1127 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1128 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1129 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1130 "Total bounce pages");
1131 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1132 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1133 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1134 "Free bounce pages");
1135 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1136 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1137 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1138 "Reserved bounce pages");
1139 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1140 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1141 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1142 "Active bounce pages");
1143 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1144 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1145 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1146 "Total bounce requests");
1147 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1148 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1149 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1150 "Total bounce requests that were deferred");
1151 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1152 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1153 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1154 "Total bounce page reservations that were failed");
1155 SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1156 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1157 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1158 SYSCTL_ADD_INT(&bz->sysctl_ctx,
1159 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1160 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1166 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1168 struct bounce_zone *bz = dmat->bounce_zone;
1169 int count = 0, mflags;
1171 if (flags & BUS_DMA_NOWAIT)
1176 while (numpages > 0) {
1177 struct bounce_page *bpage;
1179 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1181 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1185 if (bpage->vaddr == 0) {
1186 kfree(bpage, M_DEVBUF);
1189 bpage->busaddr = pmap_kextract(bpage->vaddr);
1192 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1193 total_bounce_pages++;
1204 /* Assume caller holds bounce zone spinlock */
1206 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1208 struct bounce_zone *bz = dmat->bounce_zone;
1211 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1212 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1213 bz->reserve_failed++;
1214 return (map->pagesneeded - (map->pagesreserved + pages));
1217 bz->free_bpages -= pages;
1219 bz->reserved_bpages += pages;
1220 KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1222 map->pagesreserved += pages;
1223 pages = map->pagesneeded - map->pagesreserved;
1229 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1231 struct bounce_zone *bz = dmat->bounce_zone;
1232 int reserved = map->pagesreserved;
1233 bus_dmamap_t wait_map;
1235 map->pagesreserved = 0;
1236 map->pagesneeded = 0;
1243 bz->free_bpages += reserved;
1244 KKASSERT(bz->free_bpages <= bz->total_bpages);
1246 KKASSERT(bz->reserved_bpages >= reserved);
1247 bz->reserved_bpages -= reserved;
1249 wait_map = get_map_waiting(dmat);
1253 if (wait_map != NULL)
1254 add_map_callback(map);
1258 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1261 struct bounce_zone *bz = dmat->bounce_zone;
1262 struct bounce_page *bpage;
1264 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1267 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1268 map->pagesreserved--;
1272 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1273 KASSERT(bpage != NULL, ("free page list is empty"));
1274 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1276 KKASSERT(bz->reserved_bpages > 0);
1277 bz->reserved_bpages--;
1279 bz->active_bpages++;
1280 KKASSERT(bz->active_bpages <= bz->total_bpages);
1284 bpage->datavaddr = vaddr;
1285 bpage->datacount = size;
1286 STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1287 return bpage->busaddr;
1291 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1293 struct bounce_zone *bz = dmat->bounce_zone;
1296 bpage->datavaddr = 0;
1297 bpage->datacount = 0;
1301 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1304 KKASSERT(bz->free_bpages <= bz->total_bpages);
1306 KKASSERT(bz->active_bpages > 0);
1307 bz->active_bpages--;
1309 map = get_map_waiting(dmat);
1314 add_map_callback(map);
1317 /* Assume caller holds bounce zone spinlock */
1319 get_map_waiting(bus_dma_tag_t dmat)
1321 struct bounce_zone *bz = dmat->bounce_zone;
1324 map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1326 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1327 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1328 bz->total_deferred++;
1337 add_map_callback(bus_dmamap_t map)
1339 spin_lock(&bounce_map_list_spin);
1340 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1341 busdma_swi_pending = 1;
1343 spin_unlock(&bounce_map_list_spin);
1351 spin_lock(&bounce_map_list_spin);
1352 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1353 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1354 spin_unlock(&bounce_map_list_spin);
1355 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1356 map->callback, map->callback_arg, /*flags*/0);
1357 spin_lock(&bounce_map_list_spin);
1359 spin_unlock(&bounce_map_list_spin);