2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1997, 1998 Justin T. Gibbs.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions, and the following disclaimer,
12 * without modification, immediately at the beginning of the file.
13 * 2. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/domainset.h>
35 #include <sys/malloc.h>
37 #include <sys/interrupt.h>
38 #include <sys/kernel.h>
42 #include <sys/memdesc.h>
43 #include <sys/mutex.h>
44 #include <sys/sysctl.h>
48 #include <vm/vm_extern.h>
49 #include <vm/vm_kern.h>
50 #include <vm/vm_page.h>
51 #include <vm/vm_map.h>
53 #include <machine/atomic.h>
54 #include <machine/bus.h>
55 #include <machine/md_var.h>
56 #include <machine/specialreg.h>
57 #include <x86/include/busdma_impl.h>
60 #define MAX_BPAGES (Maxmem > atop(0x100000000ULL) ? 8192 : 512)
62 #define MAX_BPAGES 8192
66 BUS_DMA_COULD_BOUNCE = 0x01,
67 BUS_DMA_MIN_ALLOC_COMP = 0x02,
68 BUS_DMA_KMEM_ALLOC = 0x04,
74 struct bus_dma_tag_common common;
77 bus_dma_segment_t *segments;
78 struct bounce_zone *bounce_zone;
82 vm_offset_t vaddr; /* kva of bounce buffer */
83 bus_addr_t busaddr; /* Physical address */
84 vm_offset_t datavaddr; /* kva of client data */
85 vm_offset_t dataoffs; /* page offset of client data */
86 vm_page_t datapage[2]; /* physical page(s) of client data */
87 bus_size_t datacount; /* client data count */
88 STAILQ_ENTRY(bounce_page) links;
91 int busdma_swi_pending;
94 STAILQ_ENTRY(bounce_zone) links;
95 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
104 bus_size_t alignment;
108 struct sysctl_ctx_list sysctl_tree;
109 struct sysctl_oid *sysctl_tree_top;
112 static struct mtx bounce_lock;
113 static int total_bpages;
114 static int busdma_zonecount;
115 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
117 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
118 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
119 "Total bounce pages");
122 struct bp_list bpages;
127 bus_dmamap_callback_t *callback;
129 STAILQ_ENTRY(bus_dmamap) links;
132 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
133 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
134 static struct bus_dmamap nobounce_dmamap;
136 static void init_bounce_pages(void *dummy);
137 static int alloc_bounce_zone(bus_dma_tag_t dmat);
138 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
139 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
141 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
142 vm_offset_t vaddr, vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size);
143 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
144 static bool _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf,
145 bus_size_t buflen, int *pagesneeded);
146 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
147 pmap_t pmap, void *buf, bus_size_t buflen, int flags);
148 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
149 vm_paddr_t buf, bus_size_t buflen, int flags);
150 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
154 bounce_bus_dma_zone_setup(bus_dma_tag_t dmat)
156 struct bounce_zone *bz;
160 if ((error = alloc_bounce_zone(dmat)) != 0)
162 bz = dmat->bounce_zone;
164 if (ptoa(bz->total_bpages) < dmat->common.maxsize) {
167 pages = atop(dmat->common.maxsize) - bz->total_bpages;
169 /* Add pages to our bounce pool */
170 if (alloc_bounce_pages(dmat, pages) < pages)
173 /* Performed initial allocation */
174 dmat->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
180 * Allocate a device specific dma_tag.
183 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
184 bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
185 bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
186 int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
187 void *lockfuncarg, bus_dma_tag_t *dmat)
189 bus_dma_tag_t newtag;
193 error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
194 NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
195 maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
196 sizeof (struct bus_dma_tag), (void **)&newtag);
200 newtag->common.impl = &bus_dma_bounce_impl;
201 newtag->map_count = 0;
202 newtag->segments = NULL;
204 if (parent != NULL && (newtag->common.filter != NULL ||
205 (parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0))
206 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
208 if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
209 newtag->common.alignment > 1)
210 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
212 if ((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
213 (flags & BUS_DMA_ALLOCNOW) != 0)
214 error = bounce_bus_dma_zone_setup(newtag);
219 free(newtag, M_DEVBUF);
222 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
223 __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
229 bounce_bus_dma_id_mapped(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen)
232 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0)
234 return (!_bus_dmamap_pagesneeded(dmat, buf, buflen, NULL));
238 * Update the domain for the tag. We may need to reallocate the zone and
242 bounce_bus_dma_tag_set_domain(bus_dma_tag_t dmat)
245 KASSERT(dmat->map_count == 0,
246 ("bounce_bus_dma_tag_set_domain: Domain set after use.\n"));
247 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0 ||
248 dmat->bounce_zone == NULL)
250 dmat->bounce_flags &= ~BUS_DMA_MIN_ALLOC_COMP;
251 return (bounce_bus_dma_zone_setup(dmat));
255 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
257 bus_dma_tag_t dmat_copy, parent;
264 if (dmat->map_count != 0) {
268 while (dmat != NULL) {
269 parent = (bus_dma_tag_t)dmat->common.parent;
270 atomic_subtract_int(&dmat->common.ref_count, 1);
271 if (dmat->common.ref_count == 0) {
272 if (dmat->segments != NULL)
273 free_domain(dmat->segments, M_DEVBUF);
274 free(dmat, M_DEVBUF);
276 * Last reference count, so
277 * release our reference
278 * count on our parent.
286 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
291 * Allocate a handle for mapping from kva/uva/physical
292 * address space into bus device space.
295 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
297 struct bounce_zone *bz;
298 int error, maxpages, pages;
302 if (dmat->segments == NULL) {
303 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
304 sizeof(bus_dma_segment_t) * dmat->common.nsegments,
305 M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT);
306 if (dmat->segments == NULL) {
307 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
308 __func__, dmat, ENOMEM);
314 * Bouncing might be required if the driver asks for an active
315 * exclusion region, a data alignment that is stricter than 1, and/or
316 * an active address boundary.
318 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
320 if (dmat->bounce_zone == NULL) {
321 if ((error = alloc_bounce_zone(dmat)) != 0)
324 bz = dmat->bounce_zone;
326 *mapp = (bus_dmamap_t)malloc_domainset(sizeof(**mapp), M_DEVBUF,
327 DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
329 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
330 __func__, dmat, ENOMEM);
334 /* Initialize the new map */
335 STAILQ_INIT(&((*mapp)->bpages));
338 * Attempt to add pages to our pool on a per-instance
339 * basis up to a sane limit.
341 if (dmat->common.alignment > 1)
342 maxpages = MAX_BPAGES;
344 maxpages = MIN(MAX_BPAGES, Maxmem -
345 atop(dmat->common.lowaddr));
346 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
347 (bz->map_count > 0 && bz->total_bpages < maxpages)) {
348 pages = MAX(atop(dmat->common.maxsize), 1);
349 pages = MIN(maxpages - bz->total_bpages, pages);
350 pages = MAX(pages, 1);
351 if (alloc_bounce_pages(dmat, pages) < pages)
353 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
356 dmat->bounce_flags |=
357 BUS_DMA_MIN_ALLOC_COMP;
368 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
369 __func__, dmat, dmat->common.flags, error);
374 * Destroy a handle for mapping from kva/uva/physical
375 * address space into bus device space.
378 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
381 if (map != NULL && map != &nobounce_dmamap) {
382 if (STAILQ_FIRST(&map->bpages) != NULL) {
383 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
384 __func__, dmat, EBUSY);
387 if (dmat->bounce_zone)
388 dmat->bounce_zone->map_count--;
389 free_domain(map, M_DEVBUF);
392 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
398 * Allocate a piece of memory that can be efficiently mapped into
399 * bus device space based on the constraints lited in the dma tag.
400 * A dmamap to for use with dmamap_load is also allocated.
403 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
409 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
411 if (flags & BUS_DMA_NOWAIT)
416 /* If we succeed, no mapping/bouncing will be required */
419 if (dmat->segments == NULL) {
420 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
421 sizeof(bus_dma_segment_t) * dmat->common.nsegments,
422 M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), mflags);
423 if (dmat->segments == NULL) {
424 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
425 __func__, dmat, dmat->common.flags, ENOMEM);
429 if (flags & BUS_DMA_ZERO)
431 if (flags & BUS_DMA_NOCACHE)
432 attr = VM_MEMATTR_UNCACHEABLE;
434 attr = VM_MEMATTR_DEFAULT;
437 * Allocate the buffer from the malloc(9) allocator if...
438 * - It's small enough to fit into a single power of two sized bucket.
439 * - The alignment is less than or equal to the maximum size
440 * - The low address requirement is fulfilled.
441 * else allocate non-contiguous pages if...
442 * - The page count that could get allocated doesn't exceed
443 * nsegments also when the maximum segment size is less
445 * - The alignment constraint isn't larger than a page boundary.
446 * - There are no boundary-crossing constraints.
447 * else allocate a block of contiguous pages because one or more of the
448 * constraints is something that only the contig allocator can fulfill.
450 * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
451 * below is just a quick hack. The exact alignment guarantees
452 * of malloc(9) need to be nailed down, and the code below
453 * should be rewritten to take that into account.
455 * In the meantime warn the user if malloc gets it wrong.
457 if (dmat->common.maxsize <= PAGE_SIZE &&
458 dmat->common.alignment <= dmat->common.maxsize &&
459 dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
460 attr == VM_MEMATTR_DEFAULT) {
461 *vaddr = malloc_domainset(dmat->common.maxsize, M_DEVBUF,
462 DOMAINSET_PREF(dmat->common.domain), mflags);
463 } else if (dmat->common.nsegments >=
464 howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz,
466 dmat->common.alignment <= PAGE_SIZE &&
467 (dmat->common.boundary % PAGE_SIZE) == 0) {
468 /* Page-based multi-segment allocations allowed */
469 *vaddr = (void *)kmem_alloc_attr_domainset(
470 DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
471 mflags, 0ul, dmat->common.lowaddr, attr);
472 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
474 *vaddr = (void *)kmem_alloc_contig_domainset(
475 DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
476 mflags, 0ul, dmat->common.lowaddr,
477 dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
478 dmat->common.boundary, attr);
479 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
481 if (*vaddr == NULL) {
482 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
483 __func__, dmat, dmat->common.flags, ENOMEM);
485 } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
486 printf("bus_dmamem_alloc failed to align memory properly.\n");
488 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
489 __func__, dmat, dmat->common.flags, 0);
494 * Free a piece of memory and it's allociated dmamap, that was allocated
495 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
498 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
501 * dmamem does not need to be bounced, so the map should be
502 * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
503 * was used and set if kmem_alloc_contig() was used.
506 panic("bus_dmamem_free: Invalid map freed\n");
507 if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
508 free_domain(vaddr, M_DEVBUF);
510 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
511 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
516 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
524 * Count the number of bounce pages needed in order to
525 * complete this transfer
529 while (buflen != 0) {
530 sgsize = MIN(buflen, dmat->common.maxsegsz);
531 if (bus_dma_run_filter(&dmat->common, curaddr)) {
533 PAGE_SIZE - (curaddr & PAGE_MASK));
534 if (pagesneeded == NULL)
542 if (pagesneeded != NULL)
543 *pagesneeded = count;
548 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
549 bus_size_t buflen, int flags)
552 if (map != &nobounce_dmamap && map->pagesneeded == 0) {
553 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
554 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
559 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
560 void *buf, bus_size_t buflen, int flags)
563 vm_offset_t vendaddr;
567 if (map != &nobounce_dmamap && map->pagesneeded == 0) {
568 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
569 "alignment= %d", dmat->common.lowaddr,
570 ptoa((vm_paddr_t)Maxmem),
571 dmat->common.boundary, dmat->common.alignment);
572 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
573 map, &nobounce_dmamap, map->pagesneeded);
575 * Count the number of bounce pages
576 * needed in order to complete this transfer
578 vaddr = (vm_offset_t)buf;
579 vendaddr = (vm_offset_t)buf + buflen;
581 while (vaddr < vendaddr) {
582 sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
583 if (pmap == kernel_pmap)
584 paddr = pmap_kextract(vaddr);
586 paddr = pmap_extract(pmap, vaddr);
587 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
588 sg_len = roundup2(sg_len,
589 dmat->common.alignment);
594 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
599 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
600 int ma_offs, bus_size_t buflen, int flags)
602 bus_size_t sg_len, max_sgsize;
606 if (map != &nobounce_dmamap && map->pagesneeded == 0) {
607 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
608 "alignment= %d", dmat->common.lowaddr,
609 ptoa((vm_paddr_t)Maxmem),
610 dmat->common.boundary, dmat->common.alignment);
611 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
612 map, &nobounce_dmamap, map->pagesneeded);
615 * Count the number of bounce pages
616 * needed in order to complete this transfer
620 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
621 sg_len = PAGE_SIZE - ma_offs;
622 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
623 sg_len = MIN(sg_len, max_sgsize);
624 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
625 sg_len = roundup2(sg_len,
626 dmat->common.alignment);
627 sg_len = MIN(sg_len, max_sgsize);
628 KASSERT((sg_len & (dmat->common.alignment - 1))
629 == 0, ("Segment size is not aligned"));
632 if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
634 ma_offs = (ma_offs + sg_len) & PAGE_MASK;
635 KASSERT(buflen >= sg_len,
636 ("Segment length overruns original buffer"));
639 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
644 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
647 /* Reserve Necessary Bounce Pages */
648 mtx_lock(&bounce_lock);
649 if (flags & BUS_DMA_NOWAIT) {
650 if (reserve_bounce_pages(dmat, map, 0) != 0) {
651 mtx_unlock(&bounce_lock);
655 if (reserve_bounce_pages(dmat, map, 1) != 0) {
656 /* Queue us for resources */
657 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
658 mtx_unlock(&bounce_lock);
659 return (EINPROGRESS);
662 mtx_unlock(&bounce_lock);
668 * Add a single contiguous physical range to the segment list.
671 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t curaddr,
672 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
674 bus_addr_t baddr, bmask;
677 KASSERT(curaddr <= BUS_SPACE_MAXADDR,
678 ("ds_addr %#jx > BUS_SPACE_MAXADDR %#jx; dmat %p fl %#x low %#jx "
680 (uintmax_t)curaddr, (uintmax_t)BUS_SPACE_MAXADDR,
681 dmat, dmat->bounce_flags, (uintmax_t)dmat->common.lowaddr,
682 (uintmax_t)dmat->common.highaddr));
685 * Make sure we don't cross any boundaries.
687 bmask = ~(dmat->common.boundary - 1);
688 if (dmat->common.boundary > 0) {
689 baddr = (curaddr + dmat->common.boundary) & bmask;
690 if (sgsize > (baddr - curaddr))
691 sgsize = (baddr - curaddr);
695 * Insert chunk into a segment, coalescing with
696 * previous segment if possible.
701 segs[seg].ds_addr = curaddr;
702 segs[seg].ds_len = sgsize;
704 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
705 (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
706 (dmat->common.boundary == 0 ||
707 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
708 segs[seg].ds_len += sgsize;
710 if (++seg >= dmat->common.nsegments)
712 segs[seg].ds_addr = curaddr;
713 segs[seg].ds_len = sgsize;
721 * Utility function to load a physical buffer. segp contains
722 * the starting segment on entrace, and the ending segment on exit.
725 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
726 vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
734 map = &nobounce_dmamap;
737 segs = dmat->segments;
739 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
740 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
741 if (map->pagesneeded != 0) {
742 error = _bus_dmamap_reserve_pages(dmat, map, flags);
750 sgsize = MIN(buflen, dmat->common.maxsegsz);
751 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
752 map->pagesneeded != 0 &&
753 bus_dma_run_filter(&dmat->common, curaddr)) {
754 sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
755 curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
758 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
769 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
773 * Utility function to load a linear buffer. segp contains
774 * the starting segment on entrace, and the ending segment on exit.
777 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
778 bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
781 bus_size_t sgsize, max_sgsize;
783 vm_offset_t kvaddr, vaddr;
787 map = &nobounce_dmamap;
790 segs = dmat->segments;
792 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
793 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
794 if (map->pagesneeded != 0) {
795 error = _bus_dmamap_reserve_pages(dmat, map, flags);
801 vaddr = (vm_offset_t)buf;
804 * Get the physical address for this segment.
806 if (pmap == kernel_pmap) {
807 curaddr = pmap_kextract(vaddr);
810 curaddr = pmap_extract(pmap, vaddr);
815 * Compute the segment size, and adjust counts.
817 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
818 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
819 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
820 map->pagesneeded != 0 &&
821 bus_dma_run_filter(&dmat->common, curaddr)) {
822 sgsize = roundup2(sgsize, dmat->common.alignment);
823 sgsize = MIN(sgsize, max_sgsize);
824 curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
827 sgsize = MIN(sgsize, max_sgsize);
829 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
840 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
844 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
845 struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
846 bus_dma_segment_t *segs, int *segp)
848 vm_paddr_t paddr, next_paddr;
849 int error, page_index;
850 bus_size_t sgsize, max_sgsize;
852 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
854 * If we have to keep the offset of each page this function
855 * is not suitable, switch back to bus_dmamap_load_ma_triv
856 * which is going to do the right thing in this case.
858 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
864 map = &nobounce_dmamap;
867 segs = dmat->segments;
869 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
870 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
871 if (map->pagesneeded != 0) {
872 error = _bus_dmamap_reserve_pages(dmat, map, flags);
881 * Compute the segment size, and adjust counts.
883 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
884 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
885 sgsize = PAGE_SIZE - ma_offs;
886 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
887 map->pagesneeded != 0 &&
888 bus_dma_run_filter(&dmat->common, paddr)) {
889 sgsize = roundup2(sgsize, dmat->common.alignment);
890 sgsize = MIN(sgsize, max_sgsize);
891 KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
892 ("Segment size is not aligned"));
894 * Check if two pages of the user provided buffer
897 if ((ma_offs + sgsize) > PAGE_SIZE)
899 VM_PAGE_TO_PHYS(ma[page_index + 1]);
902 paddr = add_bounce_page(dmat, map, 0, paddr,
905 sgsize = MIN(sgsize, max_sgsize);
907 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
911 KASSERT(buflen >= sgsize,
912 ("Segment length overruns original buffer"));
914 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
916 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
922 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
926 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
927 struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
934 map->callback = callback;
935 map->callback_arg = callback_arg;
938 static bus_dma_segment_t *
939 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
940 bus_dma_segment_t *segs, int nsegs, int error)
944 segs = dmat->segments;
949 * Release the mapping held by map.
952 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
954 struct bounce_page *bpage;
959 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
960 STAILQ_REMOVE_HEAD(&map->bpages, links);
961 free_bounce_page(dmat, bpage);
966 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
969 struct bounce_page *bpage;
970 vm_offset_t datavaddr, tempvaddr;
971 bus_size_t datacount1, datacount2;
973 if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
977 * Handle data bouncing. We might also want to add support for
978 * invalidating the caches on broken hardware.
980 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
981 "performing bounce", __func__, dmat, dmat->common.flags, op);
983 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
984 while (bpage != NULL) {
986 datavaddr = bpage->datavaddr;
987 datacount1 = bpage->datacount;
988 if (datavaddr == 0) {
990 pmap_quick_enter_page(bpage->datapage[0]);
991 datavaddr = tempvaddr | bpage->dataoffs;
992 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
996 bcopy((void *)datavaddr,
997 (void *)bpage->vaddr, datacount1);
1000 pmap_quick_remove_page(tempvaddr);
1002 if (bpage->datapage[1] == 0) {
1003 KASSERT(datacount1 == bpage->datacount,
1004 ("Mismatch between data size and provided memory space"));
1009 * We are dealing with an unmapped buffer that expands
1012 datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1013 datacount2 = bpage->datacount - datacount1;
1014 bcopy((void *)datavaddr,
1015 (void *)(bpage->vaddr + datacount1), datacount2);
1016 pmap_quick_remove_page(datavaddr);
1019 bpage = STAILQ_NEXT(bpage, links);
1021 dmat->bounce_zone->total_bounced++;
1024 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1025 while (bpage != NULL) {
1027 datavaddr = bpage->datavaddr;
1028 datacount1 = bpage->datacount;
1029 if (datavaddr == 0) {
1031 pmap_quick_enter_page(bpage->datapage[0]);
1032 datavaddr = tempvaddr | bpage->dataoffs;
1033 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
1037 bcopy((void *)bpage->vaddr, (void *)datavaddr,
1041 pmap_quick_remove_page(tempvaddr);
1043 if (bpage->datapage[1] == 0) {
1044 KASSERT(datacount1 == bpage->datacount,
1045 ("Mismatch between data size and provided memory space"));
1050 * We are dealing with an unmapped buffer that expands
1053 datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1054 datacount2 = bpage->datacount - datacount1;
1055 bcopy((void *)(bpage->vaddr + datacount1),
1056 (void *)datavaddr, datacount2);
1057 pmap_quick_remove_page(datavaddr);
1060 bpage = STAILQ_NEXT(bpage, links);
1062 dmat->bounce_zone->total_bounced++;
1067 init_bounce_pages(void *dummy __unused)
1071 STAILQ_INIT(&bounce_zone_list);
1072 STAILQ_INIT(&bounce_map_waitinglist);
1073 STAILQ_INIT(&bounce_map_callbacklist);
1074 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1076 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1078 static struct sysctl_ctx_list *
1079 busdma_sysctl_tree(struct bounce_zone *bz)
1082 return (&bz->sysctl_tree);
1085 static struct sysctl_oid *
1086 busdma_sysctl_tree_top(struct bounce_zone *bz)
1089 return (bz->sysctl_tree_top);
1093 alloc_bounce_zone(bus_dma_tag_t dmat)
1095 struct bounce_zone *bz;
1097 /* Check to see if we already have a suitable zone */
1098 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1099 if (dmat->common.alignment <= bz->alignment &&
1100 dmat->common.lowaddr >= bz->lowaddr &&
1101 dmat->common.domain == bz->domain) {
1102 dmat->bounce_zone = bz;
1107 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1108 M_NOWAIT | M_ZERO)) == NULL)
1111 STAILQ_INIT(&bz->bounce_page_list);
1112 bz->free_bpages = 0;
1113 bz->reserved_bpages = 0;
1114 bz->active_bpages = 0;
1115 bz->lowaddr = dmat->common.lowaddr;
1116 bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1118 bz->domain = dmat->common.domain;
1119 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1121 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1122 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1123 dmat->bounce_zone = bz;
1125 sysctl_ctx_init(&bz->sysctl_tree);
1126 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1127 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1129 if (bz->sysctl_tree_top == NULL) {
1130 sysctl_ctx_free(&bz->sysctl_tree);
1131 return (0); /* XXX error code? */
1134 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1135 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1136 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1137 "Total bounce pages");
1138 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1139 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1140 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1141 "Free bounce pages");
1142 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1143 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1144 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1145 "Reserved bounce pages");
1146 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1147 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1148 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1149 "Active bounce pages");
1150 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1151 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1152 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1153 "Total bounce requests");
1154 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1155 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1156 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1157 "Total bounce requests that were deferred");
1158 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1159 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1160 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1161 SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1162 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1163 "alignment", CTLFLAG_RD, &bz->alignment, "");
1164 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1165 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1166 "domain", CTLFLAG_RD, &bz->domain, 0,
1173 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1175 struct bounce_zone *bz;
1178 bz = dmat->bounce_zone;
1180 while (numpages > 0) {
1181 struct bounce_page *bpage;
1183 bpage = malloc_domainset(sizeof(*bpage), M_DEVBUF,
1184 DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
1188 bpage->vaddr = (vm_offset_t)contigmalloc_domainset(PAGE_SIZE,
1189 M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT,
1190 0ul, bz->lowaddr, PAGE_SIZE, 0);
1191 if (bpage->vaddr == 0) {
1192 free_domain(bpage, M_DEVBUF);
1195 bpage->busaddr = pmap_kextract(bpage->vaddr);
1196 mtx_lock(&bounce_lock);
1197 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1201 mtx_unlock(&bounce_lock);
1209 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1211 struct bounce_zone *bz;
1214 mtx_assert(&bounce_lock, MA_OWNED);
1215 bz = dmat->bounce_zone;
1216 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1217 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1218 return (map->pagesneeded - (map->pagesreserved + pages));
1219 bz->free_bpages -= pages;
1220 bz->reserved_bpages += pages;
1221 map->pagesreserved += pages;
1222 pages = map->pagesneeded - map->pagesreserved;
1228 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1229 vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size)
1231 struct bounce_zone *bz;
1232 struct bounce_page *bpage;
1234 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1235 KASSERT(map != NULL && map != &nobounce_dmamap,
1236 ("add_bounce_page: bad map %p", map));
1238 bz = dmat->bounce_zone;
1239 if (map->pagesneeded == 0)
1240 panic("add_bounce_page: map doesn't need any pages");
1243 if (map->pagesreserved == 0)
1244 panic("add_bounce_page: map doesn't need any pages");
1245 map->pagesreserved--;
1247 mtx_lock(&bounce_lock);
1248 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1250 panic("add_bounce_page: free page list is empty");
1252 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1253 bz->reserved_bpages--;
1254 bz->active_bpages++;
1255 mtx_unlock(&bounce_lock);
1257 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1258 /* Page offset needs to be preserved. */
1259 bpage->vaddr |= addr1 & PAGE_MASK;
1260 bpage->busaddr |= addr1 & PAGE_MASK;
1262 ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1264 bpage->datavaddr = vaddr;
1265 bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1266 KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1267 bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1268 bpage->dataoffs = addr1 & PAGE_MASK;
1269 bpage->datacount = size;
1270 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1271 return (bpage->busaddr);
1275 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1277 struct bus_dmamap *map;
1278 struct bounce_zone *bz;
1280 bz = dmat->bounce_zone;
1281 bpage->datavaddr = 0;
1282 bpage->datacount = 0;
1283 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1285 * Reset the bounce page to start at offset 0. Other uses
1286 * of this bounce page may need to store a full page of
1287 * data and/or assume it starts on a page boundary.
1289 bpage->vaddr &= ~PAGE_MASK;
1290 bpage->busaddr &= ~PAGE_MASK;
1293 mtx_lock(&bounce_lock);
1294 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1296 bz->active_bpages--;
1297 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1298 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1299 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1300 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1302 busdma_swi_pending = 1;
1303 bz->total_deferred++;
1304 swi_sched(vm_ih, 0);
1307 mtx_unlock(&bounce_lock);
1314 struct bus_dmamap *map;
1316 mtx_lock(&bounce_lock);
1317 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1318 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1319 mtx_unlock(&bounce_lock);
1321 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1322 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1323 map->callback, map->callback_arg, BUS_DMA_WAITOK);
1324 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1326 mtx_lock(&bounce_lock);
1328 mtx_unlock(&bounce_lock);
1331 struct bus_dma_impl bus_dma_bounce_impl = {
1332 .tag_create = bounce_bus_dma_tag_create,
1333 .tag_destroy = bounce_bus_dma_tag_destroy,
1334 .tag_set_domain = bounce_bus_dma_tag_set_domain,
1335 .id_mapped = bounce_bus_dma_id_mapped,
1336 .map_create = bounce_bus_dmamap_create,
1337 .map_destroy = bounce_bus_dmamap_destroy,
1338 .mem_alloc = bounce_bus_dmamem_alloc,
1339 .mem_free = bounce_bus_dmamem_free,
1340 .load_phys = bounce_bus_dmamap_load_phys,
1341 .load_buffer = bounce_bus_dmamap_load_buffer,
1342 .load_ma = bounce_bus_dmamap_load_ma,
1343 .map_waitok = bounce_bus_dmamap_waitok,
1344 .map_complete = bounce_bus_dmamap_complete,
1345 .map_unload = bounce_bus_dmamap_unload,
1346 .map_sync = bounce_bus_dmamap_sync,