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;
400 * Allocate the buffer from the malloc(9) allocator if...
401 * - It's small enough to fit into a single power of two sized bucket.
402 * - The alignment is less than or equal to the maximum size
403 * - The low address requirement is fulfilled.
404 * else allocate non-contiguous pages if...
405 * - The page count that could get allocated doesn't exceed
406 * nsegments also when the maximum segment size is less
408 * - The alignment constraint isn't larger than a page boundary.
409 * - There are no boundary-crossing constraints.
410 * else allocate a block of contiguous pages because one or more of the
411 * constraints is something that only the contig allocator can fulfill.
413 * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
414 * below is just a quick hack. The exact alignment guarantees
415 * of malloc(9) need to be nailed down, and the code below
416 * should be rewritten to take that into account.
418 * In the meantime warn the user if malloc gets it wrong.
420 if ((dmat->common.maxsize <= PAGE_SIZE) &&
421 (dmat->common.alignment <= dmat->common.maxsize) &&
422 dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
423 attr == VM_MEMATTR_DEFAULT) {
424 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
425 } else if (dmat->common.nsegments >=
426 howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
427 dmat->common.alignment <= PAGE_SIZE &&
428 (dmat->common.boundary % PAGE_SIZE) == 0) {
429 /* Page-based multi-segment allocations allowed */
430 *vaddr = (void *)kmem_alloc_attr(kernel_arena,
431 dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
433 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
435 *vaddr = (void *)kmem_alloc_contig(kernel_arena,
436 dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
437 dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
438 dmat->common.boundary, attr);
439 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
441 if (*vaddr == NULL) {
442 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
443 __func__, dmat, dmat->common.flags, ENOMEM);
445 } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
446 printf("bus_dmamem_alloc failed to align memory properly.\n");
448 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
449 __func__, dmat, dmat->common.flags, 0);
454 * Free a piece of memory and it's allociated dmamap, that was allocated
455 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
458 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
461 * dmamem does not need to be bounced, so the map should be
462 * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
463 * was used and set if kmem_alloc_contig() was used.
466 panic("bus_dmamem_free: Invalid map freed\n");
467 if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
468 free(vaddr, M_DEVBUF);
470 kmem_free(kernel_arena, (vm_offset_t)vaddr,
471 dmat->common.maxsize);
472 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
477 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
478 bus_size_t buflen, int flags)
483 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
485 * Count the number of bounce pages
486 * needed in order to complete this transfer
489 while (buflen != 0) {
490 sgsize = MIN(buflen, dmat->common.maxsegsz);
491 if (bus_dma_run_filter(&dmat->common, curaddr)) {
493 PAGE_SIZE - (curaddr & PAGE_MASK));
499 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
504 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
505 void *buf, bus_size_t buflen, int flags)
508 vm_offset_t vendaddr;
512 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
513 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
514 "alignment= %d", dmat->common.lowaddr,
515 ptoa((vm_paddr_t)Maxmem),
516 dmat->common.boundary, dmat->common.alignment);
517 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
518 map, &nobounce_dmamap, map->pagesneeded);
520 * Count the number of bounce pages
521 * needed in order to complete this transfer
523 vaddr = (vm_offset_t)buf;
524 vendaddr = (vm_offset_t)buf + buflen;
526 while (vaddr < vendaddr) {
527 sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
528 if (pmap == kernel_pmap)
529 paddr = pmap_kextract(vaddr);
531 paddr = pmap_extract(pmap, vaddr);
532 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
533 sg_len = roundup2(sg_len,
534 dmat->common.alignment);
539 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
544 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
545 int ma_offs, bus_size_t buflen, int flags)
547 bus_size_t sg_len, max_sgsize;
551 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
552 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
553 "alignment= %d", dmat->common.lowaddr,
554 ptoa((vm_paddr_t)Maxmem),
555 dmat->common.boundary, dmat->common.alignment);
556 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
557 map, &nobounce_dmamap, map->pagesneeded);
560 * Count the number of bounce pages
561 * needed in order to complete this transfer
565 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
566 sg_len = PAGE_SIZE - ma_offs;
567 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
568 sg_len = MIN(sg_len, max_sgsize);
569 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
570 sg_len = roundup2(sg_len,
571 dmat->common.alignment);
572 sg_len = MIN(sg_len, max_sgsize);
573 KASSERT((sg_len & (dmat->common.alignment - 1))
574 == 0, ("Segment size is not aligned"));
577 if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
579 ma_offs = (ma_offs + sg_len) & PAGE_MASK;
580 KASSERT(buflen >= sg_len,
581 ("Segment length overruns original buffer"));
584 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
589 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
592 /* Reserve Necessary Bounce Pages */
593 mtx_lock(&bounce_lock);
594 if (flags & BUS_DMA_NOWAIT) {
595 if (reserve_bounce_pages(dmat, map, 0) != 0) {
596 mtx_unlock(&bounce_lock);
600 if (reserve_bounce_pages(dmat, map, 1) != 0) {
601 /* Queue us for resources */
602 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
603 mtx_unlock(&bounce_lock);
604 return (EINPROGRESS);
607 mtx_unlock(&bounce_lock);
613 * Add a single contiguous physical range to the segment list.
616 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
617 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
619 bus_addr_t baddr, bmask;
623 * Make sure we don't cross any boundaries.
625 bmask = ~(dmat->common.boundary - 1);
626 if (dmat->common.boundary > 0) {
627 baddr = (curaddr + dmat->common.boundary) & bmask;
628 if (sgsize > (baddr - curaddr))
629 sgsize = (baddr - curaddr);
633 * Insert chunk into a segment, coalescing with
634 * previous segment if possible.
639 segs[seg].ds_addr = curaddr;
640 segs[seg].ds_len = sgsize;
642 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
643 (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
644 (dmat->common.boundary == 0 ||
645 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
646 segs[seg].ds_len += sgsize;
648 if (++seg >= dmat->common.nsegments)
650 segs[seg].ds_addr = curaddr;
651 segs[seg].ds_len = sgsize;
659 * Utility function to load a physical buffer. segp contains
660 * the starting segment on entrace, and the ending segment on exit.
663 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
664 vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
672 map = &nobounce_dmamap;
675 segs = dmat->segments;
677 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
678 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
679 if (map->pagesneeded != 0) {
680 error = _bus_dmamap_reserve_pages(dmat, map, flags);
688 sgsize = MIN(buflen, dmat->common.maxsegsz);
689 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
690 map->pagesneeded != 0 &&
691 bus_dma_run_filter(&dmat->common, curaddr)) {
692 sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
693 curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
696 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
707 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
711 * Utility function to load a linear buffer. segp contains
712 * the starting segment on entrace, and the ending segment on exit.
715 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
716 bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
719 bus_size_t sgsize, max_sgsize;
721 vm_offset_t kvaddr, vaddr;
725 map = &nobounce_dmamap;
728 segs = dmat->segments;
730 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
731 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
732 if (map->pagesneeded != 0) {
733 error = _bus_dmamap_reserve_pages(dmat, map, flags);
739 vaddr = (vm_offset_t)buf;
742 * Get the physical address for this segment.
744 if (pmap == kernel_pmap) {
745 curaddr = pmap_kextract(vaddr);
748 curaddr = pmap_extract(pmap, vaddr);
753 * Compute the segment size, and adjust counts.
755 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
756 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
757 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
758 map->pagesneeded != 0 &&
759 bus_dma_run_filter(&dmat->common, curaddr)) {
760 sgsize = roundup2(sgsize, dmat->common.alignment);
761 sgsize = MIN(sgsize, max_sgsize);
762 curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
765 sgsize = MIN(sgsize, max_sgsize);
767 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
778 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
782 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
783 struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
784 bus_dma_segment_t *segs, int *segp)
786 vm_paddr_t paddr, next_paddr;
787 int error, page_index;
788 bus_size_t sgsize, max_sgsize;
790 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
792 * If we have to keep the offset of each page this function
793 * is not suitable, switch back to bus_dmamap_load_ma_triv
794 * which is going to do the right thing in this case.
796 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
802 map = &nobounce_dmamap;
805 segs = dmat->segments;
807 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
808 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
809 if (map->pagesneeded != 0) {
810 error = _bus_dmamap_reserve_pages(dmat, map, flags);
819 * Compute the segment size, and adjust counts.
821 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
822 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
823 sgsize = PAGE_SIZE - ma_offs;
824 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
825 map->pagesneeded != 0 &&
826 bus_dma_run_filter(&dmat->common, paddr)) {
827 sgsize = roundup2(sgsize, dmat->common.alignment);
828 sgsize = MIN(sgsize, max_sgsize);
829 KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
830 ("Segment size is not aligned"));
832 * Check if two pages of the user provided buffer
835 if ((ma_offs + sgsize) > PAGE_SIZE)
837 VM_PAGE_TO_PHYS(ma[page_index + 1]);
840 paddr = add_bounce_page(dmat, map, 0, paddr,
843 sgsize = MIN(sgsize, max_sgsize);
845 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
849 KASSERT(buflen >= sgsize,
850 ("Segment length overruns original buffer"));
852 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
854 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
860 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
864 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
865 struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
872 map->callback = callback;
873 map->callback_arg = callback_arg;
876 static bus_dma_segment_t *
877 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
878 bus_dma_segment_t *segs, int nsegs, int error)
882 segs = dmat->segments;
887 * Release the mapping held by map.
890 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
892 struct bounce_page *bpage;
897 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
898 STAILQ_REMOVE_HEAD(&map->bpages, links);
899 free_bounce_page(dmat, bpage);
904 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
907 struct bounce_page *bpage;
908 vm_offset_t datavaddr, tempvaddr;
909 bus_size_t datacount1, datacount2;
911 if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
915 * Handle data bouncing. We might also want to add support for
916 * invalidating the caches on broken hardware.
918 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
919 "performing bounce", __func__, dmat, dmat->common.flags, op);
921 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
922 while (bpage != NULL) {
924 datavaddr = bpage->datavaddr;
925 datacount1 = bpage->datacount;
926 if (datavaddr == 0) {
928 pmap_quick_enter_page(bpage->datapage[0]);
929 datavaddr = tempvaddr | bpage->dataoffs;
930 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
934 bcopy((void *)datavaddr,
935 (void *)bpage->vaddr, datacount1);
938 pmap_quick_remove_page(tempvaddr);
940 if (bpage->datapage[1] == 0) {
941 KASSERT(datacount1 == bpage->datacount,
942 ("Mismatch between data size and provided memory space"));
947 * We are dealing with an unmapped buffer that expands
950 datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
951 datacount2 = bpage->datacount - datacount1;
952 bcopy((void *)datavaddr,
953 (void *)(bpage->vaddr + datacount1), datacount2);
954 pmap_quick_remove_page(datavaddr);
957 bpage = STAILQ_NEXT(bpage, links);
959 dmat->bounce_zone->total_bounced++;
962 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
963 while (bpage != NULL) {
965 datavaddr = bpage->datavaddr;
966 datacount1 = bpage->datacount;
967 if (datavaddr == 0) {
969 pmap_quick_enter_page(bpage->datapage[0]);
970 datavaddr = tempvaddr | bpage->dataoffs;
971 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
975 bcopy((void *)bpage->vaddr, (void *)datavaddr,
979 pmap_quick_remove_page(tempvaddr);
981 if (bpage->datapage[1] == 0) {
982 KASSERT(datacount1 == bpage->datacount,
983 ("Mismatch between data size and provided memory space"));
988 * We are dealing with an unmapped buffer that expands
991 datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
992 datacount2 = bpage->datacount - datacount1;
993 bcopy((void *)(bpage->vaddr + datacount1),
994 (void *)datavaddr, datacount2);
995 pmap_quick_remove_page(datavaddr);
998 bpage = STAILQ_NEXT(bpage, links);
1000 dmat->bounce_zone->total_bounced++;
1005 init_bounce_pages(void *dummy __unused)
1009 STAILQ_INIT(&bounce_zone_list);
1010 STAILQ_INIT(&bounce_map_waitinglist);
1011 STAILQ_INIT(&bounce_map_callbacklist);
1012 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1014 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1016 static struct sysctl_ctx_list *
1017 busdma_sysctl_tree(struct bounce_zone *bz)
1020 return (&bz->sysctl_tree);
1023 static struct sysctl_oid *
1024 busdma_sysctl_tree_top(struct bounce_zone *bz)
1027 return (bz->sysctl_tree_top);
1031 alloc_bounce_zone(bus_dma_tag_t dmat)
1033 struct bounce_zone *bz;
1035 /* Check to see if we already have a suitable zone */
1036 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1037 if ((dmat->common.alignment <= bz->alignment) &&
1038 (dmat->common.lowaddr >= bz->lowaddr)) {
1039 dmat->bounce_zone = bz;
1044 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1045 M_NOWAIT | M_ZERO)) == NULL)
1048 STAILQ_INIT(&bz->bounce_page_list);
1049 bz->free_bpages = 0;
1050 bz->reserved_bpages = 0;
1051 bz->active_bpages = 0;
1052 bz->lowaddr = dmat->common.lowaddr;
1053 bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1055 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1057 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1058 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1059 dmat->bounce_zone = bz;
1061 sysctl_ctx_init(&bz->sysctl_tree);
1062 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1063 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1065 if (bz->sysctl_tree_top == NULL) {
1066 sysctl_ctx_free(&bz->sysctl_tree);
1067 return (0); /* XXX error code? */
1070 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1071 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1072 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1073 "Total bounce pages");
1074 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1075 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1076 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1077 "Free bounce pages");
1078 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1079 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1080 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1081 "Reserved bounce pages");
1082 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1083 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1084 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1085 "Active bounce pages");
1086 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1087 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1088 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1089 "Total bounce requests");
1090 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1091 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1092 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1093 "Total bounce requests that were deferred");
1094 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1095 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1096 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1097 SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1098 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1099 "alignment", CTLFLAG_RD, &bz->alignment, "");
1105 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1107 struct bounce_zone *bz;
1110 bz = dmat->bounce_zone;
1112 while (numpages > 0) {
1113 struct bounce_page *bpage;
1115 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1120 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1125 if (bpage->vaddr == 0) {
1126 free(bpage, M_DEVBUF);
1129 bpage->busaddr = pmap_kextract(bpage->vaddr);
1130 mtx_lock(&bounce_lock);
1131 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1135 mtx_unlock(&bounce_lock);
1143 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1145 struct bounce_zone *bz;
1148 mtx_assert(&bounce_lock, MA_OWNED);
1149 bz = dmat->bounce_zone;
1150 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1151 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1152 return (map->pagesneeded - (map->pagesreserved + pages));
1153 bz->free_bpages -= pages;
1154 bz->reserved_bpages += pages;
1155 map->pagesreserved += pages;
1156 pages = map->pagesneeded - map->pagesreserved;
1162 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1163 bus_addr_t addr1, bus_addr_t addr2, bus_size_t size)
1165 struct bounce_zone *bz;
1166 struct bounce_page *bpage;
1168 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1169 KASSERT(map != NULL && map != &nobounce_dmamap,
1170 ("add_bounce_page: bad map %p", map));
1172 bz = dmat->bounce_zone;
1173 if (map->pagesneeded == 0)
1174 panic("add_bounce_page: map doesn't need any pages");
1177 if (map->pagesreserved == 0)
1178 panic("add_bounce_page: map doesn't need any pages");
1179 map->pagesreserved--;
1181 mtx_lock(&bounce_lock);
1182 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1184 panic("add_bounce_page: free page list is empty");
1186 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1187 bz->reserved_bpages--;
1188 bz->active_bpages++;
1189 mtx_unlock(&bounce_lock);
1191 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1192 /* Page offset needs to be preserved. */
1193 bpage->vaddr |= addr1 & PAGE_MASK;
1194 bpage->busaddr |= addr1 & PAGE_MASK;
1196 ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1198 bpage->datavaddr = vaddr;
1199 bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1200 KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1201 bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1202 bpage->dataoffs = addr1 & PAGE_MASK;
1203 bpage->datacount = size;
1204 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1205 return (bpage->busaddr);
1209 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1211 struct bus_dmamap *map;
1212 struct bounce_zone *bz;
1214 bz = dmat->bounce_zone;
1215 bpage->datavaddr = 0;
1216 bpage->datacount = 0;
1217 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1219 * Reset the bounce page to start at offset 0. Other uses
1220 * of this bounce page may need to store a full page of
1221 * data and/or assume it starts on a page boundary.
1223 bpage->vaddr &= ~PAGE_MASK;
1224 bpage->busaddr &= ~PAGE_MASK;
1227 mtx_lock(&bounce_lock);
1228 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1230 bz->active_bpages--;
1231 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1232 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1233 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1234 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1236 busdma_swi_pending = 1;
1237 bz->total_deferred++;
1238 swi_sched(vm_ih, 0);
1241 mtx_unlock(&bounce_lock);
1248 struct bus_dmamap *map;
1250 mtx_lock(&bounce_lock);
1251 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1252 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1253 mtx_unlock(&bounce_lock);
1255 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1256 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1257 map->callback, map->callback_arg, BUS_DMA_WAITOK);
1258 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1260 mtx_lock(&bounce_lock);
1262 mtx_unlock(&bounce_lock);
1265 struct bus_dma_impl bus_dma_bounce_impl = {
1266 .tag_create = bounce_bus_dma_tag_create,
1267 .tag_destroy = bounce_bus_dma_tag_destroy,
1268 .map_create = bounce_bus_dmamap_create,
1269 .map_destroy = bounce_bus_dmamap_destroy,
1270 .mem_alloc = bounce_bus_dmamem_alloc,
1271 .mem_free = bounce_bus_dmamem_free,
1272 .load_phys = bounce_bus_dmamap_load_phys,
1273 .load_buffer = bounce_bus_dmamap_load_buffer,
1274 .load_ma = bounce_bus_dmamap_load_ma,
1275 .map_waitok = bounce_bus_dmamap_waitok,
1276 .map_complete = bounce_bus_dmamap_complete,
1277 .map_unload = bounce_bus_dmamap_unload,
1278 .map_sync = bounce_bus_dmamap_sync