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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
34 #include <sys/interrupt.h>
35 #include <sys/kernel.h>
39 #include <sys/memdesc.h>
40 #include <sys/mutex.h>
41 #include <sys/sysctl.h>
45 #include <vm/vm_extern.h>
46 #include <vm/vm_kern.h>
47 #include <vm/vm_page.h>
48 #include <vm/vm_map.h>
50 #include <machine/atomic.h>
51 #include <machine/bus.h>
52 #include <machine/md_var.h>
53 #include <machine/specialreg.h>
54 #include <x86/include/busdma_impl.h>
57 #define MAX_BPAGES 512
59 #define MAX_BPAGES 8192
63 BUS_DMA_COULD_BOUNCE = 0x01,
64 BUS_DMA_MIN_ALLOC_COMP = 0x02,
65 BUS_DMA_KMEM_ALLOC = 0x04,
71 struct bus_dma_tag_common common;
74 bus_dma_segment_t *segments;
75 struct bounce_zone *bounce_zone;
79 vm_offset_t vaddr; /* kva of bounce buffer */
80 bus_addr_t busaddr; /* Physical address */
81 vm_offset_t datavaddr; /* kva of client data */
82 vm_offset_t dataoffs; /* page offset of client data */
83 vm_page_t datapage[2]; /* physical page(s) of client data */
84 bus_size_t datacount; /* client data count */
85 STAILQ_ENTRY(bounce_page) links;
88 int busdma_swi_pending;
91 STAILQ_ENTRY(bounce_zone) links;
92 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
100 bus_size_t alignment;
104 struct sysctl_ctx_list sysctl_tree;
105 struct sysctl_oid *sysctl_tree_top;
108 static struct mtx bounce_lock;
109 static int total_bpages;
110 static int busdma_zonecount;
111 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
113 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
114 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
115 "Total bounce pages");
118 struct bp_list bpages;
123 bus_dmamap_callback_t *callback;
125 STAILQ_ENTRY(bus_dmamap) links;
128 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
129 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
130 static struct bus_dmamap nobounce_dmamap;
132 static void init_bounce_pages(void *dummy);
133 static int alloc_bounce_zone(bus_dma_tag_t dmat);
134 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
135 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
137 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
138 vm_offset_t vaddr, bus_addr_t addr1,
139 bus_addr_t addr2, bus_size_t size);
140 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
141 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
142 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
143 pmap_t pmap, void *buf, bus_size_t buflen,
145 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
146 vm_paddr_t buf, bus_size_t buflen,
148 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
152 * Allocate a device specific dma_tag.
155 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
156 bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
157 bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
158 int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
159 void *lockfuncarg, bus_dma_tag_t *dmat)
161 bus_dma_tag_t newtag;
165 error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
166 NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
167 maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
168 sizeof (struct bus_dma_tag), (void **)&newtag);
172 newtag->common.impl = &bus_dma_bounce_impl;
173 newtag->map_count = 0;
174 newtag->segments = NULL;
176 if (parent != NULL && ((newtag->common.filter != NULL) ||
177 ((parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0)))
178 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
180 if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
181 newtag->common.alignment > 1)
182 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
184 if (((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
185 (flags & BUS_DMA_ALLOCNOW) != 0) {
186 struct bounce_zone *bz;
189 if ((error = alloc_bounce_zone(newtag)) != 0) {
190 free(newtag, M_DEVBUF);
193 bz = newtag->bounce_zone;
195 if (ptoa(bz->total_bpages) < maxsize) {
198 pages = atop(maxsize) - bz->total_bpages;
200 /* Add pages to our bounce pool */
201 if (alloc_bounce_pages(newtag, pages) < pages)
204 /* Performed initial allocation */
205 newtag->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
210 free(newtag, M_DEVBUF);
213 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
214 __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
220 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
222 bus_dma_tag_t dmat_copy, parent;
229 if (dmat->map_count != 0) {
233 while (dmat != NULL) {
234 parent = (bus_dma_tag_t)dmat->common.parent;
235 atomic_subtract_int(&dmat->common.ref_count, 1);
236 if (dmat->common.ref_count == 0) {
237 if (dmat->segments != NULL)
238 free(dmat->segments, M_DEVBUF);
239 free(dmat, M_DEVBUF);
241 * Last reference count, so
242 * release our reference
243 * count on our parent.
251 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
256 * Allocate a handle for mapping from kva/uva/physical
257 * address space into bus device space.
260 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
262 struct bounce_zone *bz;
263 int error, maxpages, pages;
267 if (dmat->segments == NULL) {
268 dmat->segments = (bus_dma_segment_t *)malloc(
269 sizeof(bus_dma_segment_t) * dmat->common.nsegments,
271 if (dmat->segments == NULL) {
272 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
273 __func__, dmat, ENOMEM);
279 * Bouncing might be required if the driver asks for an active
280 * exclusion region, a data alignment that is stricter than 1, and/or
281 * an active address boundary.
283 if (dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) {
285 if (dmat->bounce_zone == NULL) {
286 if ((error = alloc_bounce_zone(dmat)) != 0)
289 bz = dmat->bounce_zone;
291 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
294 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
295 __func__, dmat, ENOMEM);
299 /* Initialize the new map */
300 STAILQ_INIT(&((*mapp)->bpages));
303 * Attempt to add pages to our pool on a per-instance
304 * basis up to a sane limit.
306 if (dmat->common.alignment > 1)
307 maxpages = MAX_BPAGES;
309 maxpages = MIN(MAX_BPAGES, Maxmem -
310 atop(dmat->common.lowaddr));
311 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
312 (bz->map_count > 0 && bz->total_bpages < maxpages)) {
313 pages = MAX(atop(dmat->common.maxsize), 1);
314 pages = MIN(maxpages - bz->total_bpages, pages);
315 pages = MAX(pages, 1);
316 if (alloc_bounce_pages(dmat, pages) < pages)
318 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
321 dmat->bounce_flags |=
322 BUS_DMA_MIN_ALLOC_COMP;
333 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
334 __func__, dmat, dmat->common.flags, error);
339 * Destroy a handle for mapping from kva/uva/physical
340 * address space into bus device space.
343 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
346 if (map != NULL && map != &nobounce_dmamap) {
347 if (STAILQ_FIRST(&map->bpages) != NULL) {
348 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
349 __func__, dmat, EBUSY);
352 if (dmat->bounce_zone)
353 dmat->bounce_zone->map_count--;
357 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
363 * Allocate a piece of memory that can be efficiently mapped into
364 * bus device space based on the constraints lited in the dma tag.
365 * A dmamap to for use with dmamap_load is also allocated.
368 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
374 if (flags & BUS_DMA_NOWAIT)
379 /* If we succeed, no mapping/bouncing will be required */
382 if (dmat->segments == NULL) {
383 dmat->segments = (bus_dma_segment_t *)malloc(
384 sizeof(bus_dma_segment_t) * dmat->common.nsegments,
386 if (dmat->segments == NULL) {
387 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
388 __func__, dmat, dmat->common.flags, ENOMEM);
392 if (flags & BUS_DMA_ZERO)
394 if (flags & BUS_DMA_NOCACHE)
395 attr = VM_MEMATTR_UNCACHEABLE;
397 attr = VM_MEMATTR_DEFAULT;
401 * (dmat->alignment <= dmat->maxsize) is just a quick hack; the exact
402 * alignment guarantees of malloc need to be nailed down, and the
403 * code below should be rewritten to take that into account.
405 * In the meantime, we'll warn the user if malloc gets it wrong.
407 if ((dmat->common.maxsize <= PAGE_SIZE) &&
408 (dmat->common.alignment <= dmat->common.maxsize) &&
409 dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
410 attr == VM_MEMATTR_DEFAULT) {
411 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
412 } else if (dmat->common.nsegments >= btoc(dmat->common.maxsize) &&
413 dmat->common.alignment <= PAGE_SIZE &&
414 (dmat->common.boundary == 0 ||
415 dmat->common.boundary >= dmat->common.lowaddr)) {
416 /* Page-based multi-segment allocations allowed */
417 *vaddr = (void *)kmem_alloc_attr(kernel_arena,
418 dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
420 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
422 *vaddr = (void *)kmem_alloc_contig(kernel_arena,
423 dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
424 dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
425 dmat->common.boundary, attr);
426 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
428 if (*vaddr == NULL) {
429 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
430 __func__, dmat, dmat->common.flags, ENOMEM);
432 } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
433 printf("bus_dmamem_alloc failed to align memory properly.\n");
435 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
436 __func__, dmat, dmat->common.flags, 0);
441 * Free a piece of memory and it's allociated dmamap, that was allocated
442 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
445 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
448 * dmamem does not need to be bounced, so the map should be
449 * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
450 * was used and set if kmem_alloc_contig() was used.
453 panic("bus_dmamem_free: Invalid map freed\n");
454 if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
455 free(vaddr, M_DEVBUF);
457 kmem_free(kernel_arena, (vm_offset_t)vaddr,
458 dmat->common.maxsize);
459 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
464 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
465 bus_size_t buflen, int flags)
470 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
472 * Count the number of bounce pages
473 * needed in order to complete this transfer
476 while (buflen != 0) {
477 sgsize = MIN(buflen, dmat->common.maxsegsz);
478 if (bus_dma_run_filter(&dmat->common, curaddr)) {
480 PAGE_SIZE - (curaddr & PAGE_MASK));
486 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
491 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
492 void *buf, bus_size_t buflen, int flags)
495 vm_offset_t vendaddr;
499 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
500 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
501 "alignment= %d", dmat->common.lowaddr,
502 ptoa((vm_paddr_t)Maxmem),
503 dmat->common.boundary, dmat->common.alignment);
504 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
505 map, &nobounce_dmamap, map->pagesneeded);
507 * Count the number of bounce pages
508 * needed in order to complete this transfer
510 vaddr = (vm_offset_t)buf;
511 vendaddr = (vm_offset_t)buf + buflen;
513 while (vaddr < vendaddr) {
514 sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
515 if (pmap == kernel_pmap)
516 paddr = pmap_kextract(vaddr);
518 paddr = pmap_extract(pmap, vaddr);
519 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
520 sg_len = roundup2(sg_len,
521 dmat->common.alignment);
526 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
531 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
532 int ma_offs, bus_size_t buflen, int flags)
534 bus_size_t sg_len, max_sgsize;
538 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
539 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
540 "alignment= %d", dmat->common.lowaddr,
541 ptoa((vm_paddr_t)Maxmem),
542 dmat->common.boundary, dmat->common.alignment);
543 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
544 map, &nobounce_dmamap, map->pagesneeded);
547 * Count the number of bounce pages
548 * needed in order to complete this transfer
552 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
553 sg_len = PAGE_SIZE - ma_offs;
554 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
555 sg_len = MIN(sg_len, max_sgsize);
556 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
557 sg_len = roundup2(sg_len,
558 dmat->common.alignment);
559 sg_len = MIN(sg_len, max_sgsize);
560 KASSERT((sg_len & (dmat->common.alignment - 1))
561 == 0, ("Segment size is not aligned"));
564 if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
566 ma_offs = (ma_offs + sg_len) & PAGE_MASK;
567 KASSERT(buflen >= sg_len,
568 ("Segment length overruns original buffer"));
571 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
576 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
579 /* Reserve Necessary Bounce Pages */
580 mtx_lock(&bounce_lock);
581 if (flags & BUS_DMA_NOWAIT) {
582 if (reserve_bounce_pages(dmat, map, 0) != 0) {
583 mtx_unlock(&bounce_lock);
587 if (reserve_bounce_pages(dmat, map, 1) != 0) {
588 /* Queue us for resources */
589 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
590 mtx_unlock(&bounce_lock);
591 return (EINPROGRESS);
594 mtx_unlock(&bounce_lock);
600 * Add a single contiguous physical range to the segment list.
603 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
604 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
606 bus_addr_t baddr, bmask;
610 * Make sure we don't cross any boundaries.
612 bmask = ~(dmat->common.boundary - 1);
613 if (dmat->common.boundary > 0) {
614 baddr = (curaddr + dmat->common.boundary) & bmask;
615 if (sgsize > (baddr - curaddr))
616 sgsize = (baddr - curaddr);
620 * Insert chunk into a segment, coalescing with
621 * previous segment if possible.
626 segs[seg].ds_addr = curaddr;
627 segs[seg].ds_len = sgsize;
629 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
630 (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
631 (dmat->common.boundary == 0 ||
632 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
633 segs[seg].ds_len += sgsize;
635 if (++seg >= dmat->common.nsegments)
637 segs[seg].ds_addr = curaddr;
638 segs[seg].ds_len = sgsize;
646 * Utility function to load a physical buffer. segp contains
647 * the starting segment on entrace, and the ending segment on exit.
650 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
651 vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
659 map = &nobounce_dmamap;
662 segs = dmat->segments;
664 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
665 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
666 if (map->pagesneeded != 0) {
667 error = _bus_dmamap_reserve_pages(dmat, map, flags);
675 sgsize = MIN(buflen, dmat->common.maxsegsz);
676 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
677 map->pagesneeded != 0 &&
678 bus_dma_run_filter(&dmat->common, curaddr)) {
679 sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
680 curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
683 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
694 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
698 * Utility function to load a linear buffer. segp contains
699 * the starting segment on entrace, and the ending segment on exit.
702 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
703 bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
706 bus_size_t sgsize, max_sgsize;
708 vm_offset_t kvaddr, vaddr;
712 map = &nobounce_dmamap;
715 segs = dmat->segments;
717 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
718 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
719 if (map->pagesneeded != 0) {
720 error = _bus_dmamap_reserve_pages(dmat, map, flags);
726 vaddr = (vm_offset_t)buf;
729 * Get the physical address for this segment.
731 if (pmap == kernel_pmap) {
732 curaddr = pmap_kextract(vaddr);
735 curaddr = pmap_extract(pmap, vaddr);
740 * Compute the segment size, and adjust counts.
742 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
743 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
744 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
745 map->pagesneeded != 0 &&
746 bus_dma_run_filter(&dmat->common, curaddr)) {
747 sgsize = roundup2(sgsize, dmat->common.alignment);
748 sgsize = MIN(sgsize, max_sgsize);
749 curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
752 sgsize = MIN(sgsize, max_sgsize);
754 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
765 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
769 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
770 struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
771 bus_dma_segment_t *segs, int *segp)
773 vm_paddr_t paddr, next_paddr;
774 int error, page_index;
775 bus_size_t sgsize, max_sgsize;
777 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
779 * If we have to keep the offset of each page this function
780 * is not suitable, switch back to bus_dmamap_load_ma_triv
781 * which is going to do the right thing in this case.
783 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
789 map = &nobounce_dmamap;
792 segs = dmat->segments;
794 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
795 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
796 if (map->pagesneeded != 0) {
797 error = _bus_dmamap_reserve_pages(dmat, map, flags);
806 * Compute the segment size, and adjust counts.
808 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
809 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
810 sgsize = PAGE_SIZE - ma_offs;
811 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
812 map->pagesneeded != 0 &&
813 bus_dma_run_filter(&dmat->common, paddr)) {
814 sgsize = roundup2(sgsize, dmat->common.alignment);
815 sgsize = MIN(sgsize, max_sgsize);
816 KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
817 ("Segment size is not aligned"));
819 * Check if two pages of the user provided buffer
822 if ((ma_offs + sgsize) > PAGE_SIZE)
824 VM_PAGE_TO_PHYS(ma[page_index + 1]);
827 paddr = add_bounce_page(dmat, map, 0, paddr,
830 sgsize = MIN(sgsize, max_sgsize);
832 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
836 KASSERT(buflen >= sgsize,
837 ("Segment length overruns original buffer"));
839 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
841 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
847 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
851 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
852 struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
859 map->callback = callback;
860 map->callback_arg = callback_arg;
863 static bus_dma_segment_t *
864 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
865 bus_dma_segment_t *segs, int nsegs, int error)
869 segs = dmat->segments;
874 * Release the mapping held by map.
877 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
879 struct bounce_page *bpage;
884 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
885 STAILQ_REMOVE_HEAD(&map->bpages, links);
886 free_bounce_page(dmat, bpage);
891 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
894 struct bounce_page *bpage;
895 vm_offset_t datavaddr, tempvaddr;
896 bus_size_t datacount1, datacount2;
898 if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
902 * Handle data bouncing. We might also want to add support for
903 * invalidating the caches on broken hardware.
905 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
906 "performing bounce", __func__, dmat, dmat->common.flags, op);
908 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
909 while (bpage != NULL) {
911 datavaddr = bpage->datavaddr;
912 datacount1 = bpage->datacount;
913 if (datavaddr == 0) {
915 pmap_quick_enter_page(bpage->datapage[0]);
916 datavaddr = tempvaddr | bpage->dataoffs;
917 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
921 bcopy((void *)datavaddr,
922 (void *)bpage->vaddr, datacount1);
925 pmap_quick_remove_page(tempvaddr);
927 if (bpage->datapage[1] == 0) {
928 KASSERT(datacount1 == bpage->datacount,
929 ("Mismatch between data size and provided memory space"));
934 * We are dealing with an unmapped buffer that expands
937 datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
938 datacount2 = bpage->datacount - datacount1;
939 bcopy((void *)datavaddr,
940 (void *)(bpage->vaddr + datacount1), datacount2);
941 pmap_quick_remove_page(datavaddr);
944 bpage = STAILQ_NEXT(bpage, links);
946 dmat->bounce_zone->total_bounced++;
949 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
950 while (bpage != NULL) {
952 datavaddr = bpage->datavaddr;
953 datacount1 = bpage->datacount;
954 if (datavaddr == 0) {
956 pmap_quick_enter_page(bpage->datapage[0]);
957 datavaddr = tempvaddr | bpage->dataoffs;
958 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
962 bcopy((void *)bpage->vaddr, (void *)datavaddr,
966 pmap_quick_remove_page(tempvaddr);
968 if (bpage->datapage[1] == 0) {
969 KASSERT(datacount1 == bpage->datacount,
970 ("Mismatch between data size and provided memory space"));
975 * We are dealing with an unmapped buffer that expands
978 datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
979 datacount2 = bpage->datacount - datacount1;
980 bcopy((void *)(bpage->vaddr + datacount1),
981 (void *)datavaddr, datacount2);
982 pmap_quick_remove_page(datavaddr);
985 bpage = STAILQ_NEXT(bpage, links);
987 dmat->bounce_zone->total_bounced++;
992 init_bounce_pages(void *dummy __unused)
996 STAILQ_INIT(&bounce_zone_list);
997 STAILQ_INIT(&bounce_map_waitinglist);
998 STAILQ_INIT(&bounce_map_callbacklist);
999 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1001 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1003 static struct sysctl_ctx_list *
1004 busdma_sysctl_tree(struct bounce_zone *bz)
1007 return (&bz->sysctl_tree);
1010 static struct sysctl_oid *
1011 busdma_sysctl_tree_top(struct bounce_zone *bz)
1014 return (bz->sysctl_tree_top);
1018 alloc_bounce_zone(bus_dma_tag_t dmat)
1020 struct bounce_zone *bz;
1022 /* Check to see if we already have a suitable zone */
1023 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1024 if ((dmat->common.alignment <= bz->alignment) &&
1025 (dmat->common.lowaddr >= bz->lowaddr)) {
1026 dmat->bounce_zone = bz;
1031 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1032 M_NOWAIT | M_ZERO)) == NULL)
1035 STAILQ_INIT(&bz->bounce_page_list);
1036 bz->free_bpages = 0;
1037 bz->reserved_bpages = 0;
1038 bz->active_bpages = 0;
1039 bz->lowaddr = dmat->common.lowaddr;
1040 bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1042 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1044 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1045 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1046 dmat->bounce_zone = bz;
1048 sysctl_ctx_init(&bz->sysctl_tree);
1049 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1050 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1052 if (bz->sysctl_tree_top == NULL) {
1053 sysctl_ctx_free(&bz->sysctl_tree);
1054 return (0); /* XXX error code? */
1057 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1058 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1059 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1060 "Total bounce pages");
1061 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1062 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1063 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1064 "Free bounce pages");
1065 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1066 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1067 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1068 "Reserved bounce pages");
1069 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1070 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1071 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1072 "Active bounce pages");
1073 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1074 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1075 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1076 "Total bounce requests");
1077 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1078 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1079 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1080 "Total bounce requests that were deferred");
1081 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1082 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1083 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1084 SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1085 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1086 "alignment", CTLFLAG_RD, &bz->alignment, "");
1092 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1094 struct bounce_zone *bz;
1097 bz = dmat->bounce_zone;
1099 while (numpages > 0) {
1100 struct bounce_page *bpage;
1102 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1107 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1112 if (bpage->vaddr == 0) {
1113 free(bpage, M_DEVBUF);
1116 bpage->busaddr = pmap_kextract(bpage->vaddr);
1117 mtx_lock(&bounce_lock);
1118 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1122 mtx_unlock(&bounce_lock);
1130 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1132 struct bounce_zone *bz;
1135 mtx_assert(&bounce_lock, MA_OWNED);
1136 bz = dmat->bounce_zone;
1137 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1138 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1139 return (map->pagesneeded - (map->pagesreserved + pages));
1140 bz->free_bpages -= pages;
1141 bz->reserved_bpages += pages;
1142 map->pagesreserved += pages;
1143 pages = map->pagesneeded - map->pagesreserved;
1149 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1150 bus_addr_t addr1, bus_addr_t addr2, bus_size_t size)
1152 struct bounce_zone *bz;
1153 struct bounce_page *bpage;
1155 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1156 KASSERT(map != NULL && map != &nobounce_dmamap,
1157 ("add_bounce_page: bad map %p", map));
1159 bz = dmat->bounce_zone;
1160 if (map->pagesneeded == 0)
1161 panic("add_bounce_page: map doesn't need any pages");
1164 if (map->pagesreserved == 0)
1165 panic("add_bounce_page: map doesn't need any pages");
1166 map->pagesreserved--;
1168 mtx_lock(&bounce_lock);
1169 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1171 panic("add_bounce_page: free page list is empty");
1173 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1174 bz->reserved_bpages--;
1175 bz->active_bpages++;
1176 mtx_unlock(&bounce_lock);
1178 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1179 /* Page offset needs to be preserved. */
1180 bpage->vaddr |= addr1 & PAGE_MASK;
1181 bpage->busaddr |= addr1 & PAGE_MASK;
1183 ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1185 bpage->datavaddr = vaddr;
1186 bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1187 KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1188 bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1189 bpage->dataoffs = addr1 & PAGE_MASK;
1190 bpage->datacount = size;
1191 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1192 return (bpage->busaddr);
1196 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1198 struct bus_dmamap *map;
1199 struct bounce_zone *bz;
1201 bz = dmat->bounce_zone;
1202 bpage->datavaddr = 0;
1203 bpage->datacount = 0;
1204 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1206 * Reset the bounce page to start at offset 0. Other uses
1207 * of this bounce page may need to store a full page of
1208 * data and/or assume it starts on a page boundary.
1210 bpage->vaddr &= ~PAGE_MASK;
1211 bpage->busaddr &= ~PAGE_MASK;
1214 mtx_lock(&bounce_lock);
1215 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1217 bz->active_bpages--;
1218 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1219 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1220 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1221 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1223 busdma_swi_pending = 1;
1224 bz->total_deferred++;
1225 swi_sched(vm_ih, 0);
1228 mtx_unlock(&bounce_lock);
1235 struct bus_dmamap *map;
1237 mtx_lock(&bounce_lock);
1238 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1239 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1240 mtx_unlock(&bounce_lock);
1242 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1243 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1244 map->callback, map->callback_arg, BUS_DMA_WAITOK);
1245 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1247 mtx_lock(&bounce_lock);
1249 mtx_unlock(&bounce_lock);
1252 struct bus_dma_impl bus_dma_bounce_impl = {
1253 .tag_create = bounce_bus_dma_tag_create,
1254 .tag_destroy = bounce_bus_dma_tag_destroy,
1255 .map_create = bounce_bus_dmamap_create,
1256 .map_destroy = bounce_bus_dmamap_destroy,
1257 .mem_alloc = bounce_bus_dmamem_alloc,
1258 .mem_free = bounce_bus_dmamem_free,
1259 .load_phys = bounce_bus_dmamap_load_phys,
1260 .load_buffer = bounce_bus_dmamap_load_buffer,
1261 .load_ma = bounce_bus_dmamap_load_ma,
1262 .map_waitok = bounce_bus_dmamap_waitok,
1263 .map_complete = bounce_bus_dmamap_complete,
1264 .map_unload = bounce_bus_dmamap_unload,
1265 .map_sync = bounce_bus_dmamap_sync