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/malloc.h>
36 #include <sys/interrupt.h>
37 #include <sys/kernel.h>
41 #include <sys/memdesc.h>
42 #include <sys/mutex.h>
43 #include <sys/sysctl.h>
47 #include <vm/vm_extern.h>
48 #include <vm/vm_kern.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_map.h>
52 #include <machine/atomic.h>
53 #include <machine/bus.h>
54 #include <machine/md_var.h>
55 #include <machine/specialreg.h>
56 #include <x86/include/busdma_impl.h>
59 #define MAX_BPAGES 512
61 #define MAX_BPAGES 8192
65 BUS_DMA_COULD_BOUNCE = 0x01,
66 BUS_DMA_MIN_ALLOC_COMP = 0x02,
67 BUS_DMA_KMEM_ALLOC = 0x04,
73 struct bus_dma_tag_common common;
76 bus_dma_segment_t *segments;
77 struct bounce_zone *bounce_zone;
81 vm_offset_t vaddr; /* kva of bounce buffer */
82 bus_addr_t busaddr; /* Physical address */
83 vm_offset_t datavaddr; /* kva of client data */
84 vm_offset_t dataoffs; /* page offset of client data */
85 vm_page_t datapage[2]; /* physical page(s) of client data */
86 bus_size_t datacount; /* client data count */
87 STAILQ_ENTRY(bounce_page) links;
90 int busdma_swi_pending;
93 STAILQ_ENTRY(bounce_zone) links;
94 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
103 bus_size_t alignment;
107 struct sysctl_ctx_list sysctl_tree;
108 struct sysctl_oid *sysctl_tree_top;
111 static struct mtx bounce_lock;
112 static int total_bpages;
113 static int busdma_zonecount;
114 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
116 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
117 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
118 "Total bounce pages");
121 struct bp_list bpages;
126 bus_dmamap_callback_t *callback;
128 STAILQ_ENTRY(bus_dmamap) links;
131 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
132 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
133 static struct bus_dmamap nobounce_dmamap;
135 static void init_bounce_pages(void *dummy);
136 static int alloc_bounce_zone(bus_dma_tag_t dmat);
137 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
138 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
140 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
141 vm_offset_t vaddr, bus_addr_t addr1,
142 bus_addr_t addr2, bus_size_t size);
143 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
144 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
145 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
146 pmap_t pmap, void *buf, bus_size_t buflen,
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,
151 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
155 bounce_bus_dma_zone_setup(bus_dma_tag_t dmat)
157 struct bounce_zone *bz;
161 if ((error = alloc_bounce_zone(dmat)) != 0)
163 bz = dmat->bounce_zone;
165 if (ptoa(bz->total_bpages) < dmat->common.maxsize) {
168 pages = atop(dmat->common.maxsize) - bz->total_bpages;
170 /* Add pages to our bounce pool */
171 if (alloc_bounce_pages(dmat, pages) < pages)
174 /* Performed initial allocation */
175 dmat->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
181 * Allocate a device specific dma_tag.
184 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
185 bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
186 bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
187 int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
188 void *lockfuncarg, bus_dma_tag_t *dmat)
190 bus_dma_tag_t newtag;
194 error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
195 NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
196 maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
197 sizeof (struct bus_dma_tag), (void **)&newtag);
201 newtag->common.impl = &bus_dma_bounce_impl;
202 newtag->map_count = 0;
203 newtag->segments = NULL;
205 if (parent != NULL && ((newtag->common.filter != NULL) ||
206 ((parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0)))
207 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
209 if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
210 newtag->common.alignment > 1)
211 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
213 if (((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
214 (flags & BUS_DMA_ALLOCNOW) != 0)
215 error = bounce_bus_dma_zone_setup(newtag);
220 free(newtag, M_DEVBUF);
223 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
224 __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
230 * Update the domain for the tag. We may need to reallocate the zone and
234 bounce_bus_dma_tag_set_domain(bus_dma_tag_t dmat)
237 KASSERT(dmat->map_count == 0,
238 ("bounce_bus_dma_tag_set_domain: Domain set after use.\n"));
239 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0 ||
240 dmat->bounce_zone == NULL)
242 dmat->bounce_flags &= ~BUS_DMA_MIN_ALLOC_COMP;
243 return (bounce_bus_dma_zone_setup(dmat));
247 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
249 bus_dma_tag_t dmat_copy, parent;
256 if (dmat->map_count != 0) {
260 while (dmat != NULL) {
261 parent = (bus_dma_tag_t)dmat->common.parent;
262 atomic_subtract_int(&dmat->common.ref_count, 1);
263 if (dmat->common.ref_count == 0) {
264 if (dmat->segments != NULL)
265 free_domain(dmat->segments, M_DEVBUF);
266 free(dmat, M_DEVBUF);
268 * Last reference count, so
269 * release our reference
270 * count on our parent.
278 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
283 * Allocate a handle for mapping from kva/uva/physical
284 * address space into bus device space.
287 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
289 struct bounce_zone *bz;
290 int error, maxpages, pages;
292 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
296 if (dmat->segments == NULL) {
297 dmat->segments = (bus_dma_segment_t *)malloc_domain(
298 sizeof(bus_dma_segment_t) * dmat->common.nsegments,
299 M_DEVBUF, dmat->common.domain, M_NOWAIT);
300 if (dmat->segments == NULL) {
301 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
302 __func__, dmat, ENOMEM);
308 * Bouncing might be required if the driver asks for an active
309 * exclusion region, a data alignment that is stricter than 1, and/or
310 * an active address boundary.
312 if (dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) {
314 if (dmat->bounce_zone == NULL) {
315 if ((error = alloc_bounce_zone(dmat)) != 0)
318 bz = dmat->bounce_zone;
320 *mapp = (bus_dmamap_t)malloc_domain(sizeof(**mapp), M_DEVBUF,
321 dmat->common.domain, M_NOWAIT | M_ZERO);
323 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
324 __func__, dmat, ENOMEM);
328 /* Initialize the new map */
329 STAILQ_INIT(&((*mapp)->bpages));
332 * Attempt to add pages to our pool on a per-instance
333 * basis up to a sane limit.
335 if (dmat->common.alignment > 1)
336 maxpages = MAX_BPAGES;
338 maxpages = MIN(MAX_BPAGES, Maxmem -
339 atop(dmat->common.lowaddr));
340 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
341 (bz->map_count > 0 && bz->total_bpages < maxpages)) {
342 pages = MAX(atop(dmat->common.maxsize), 1);
343 pages = MIN(maxpages - bz->total_bpages, pages);
344 pages = MAX(pages, 1);
345 if (alloc_bounce_pages(dmat, pages) < pages)
347 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
350 dmat->bounce_flags |=
351 BUS_DMA_MIN_ALLOC_COMP;
362 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
363 __func__, dmat, dmat->common.flags, error);
368 * Destroy a handle for mapping from kva/uva/physical
369 * address space into bus device space.
372 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
375 if (map != NULL && map != &nobounce_dmamap) {
376 if (STAILQ_FIRST(&map->bpages) != NULL) {
377 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
378 __func__, dmat, EBUSY);
381 if (dmat->bounce_zone)
382 dmat->bounce_zone->map_count--;
383 free_domain(map, M_DEVBUF);
386 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
392 * Allocate a piece of memory that can be efficiently mapped into
393 * bus device space based on the constraints lited in the dma tag.
394 * A dmamap to for use with dmamap_load is also allocated.
397 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
403 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
405 if (flags & BUS_DMA_NOWAIT)
410 /* If we succeed, no mapping/bouncing will be required */
413 if (dmat->segments == NULL) {
414 dmat->segments = (bus_dma_segment_t *)malloc_domain(
415 sizeof(bus_dma_segment_t) * dmat->common.nsegments,
416 M_DEVBUF, dmat->common.domain, mflags);
417 if (dmat->segments == NULL) {
418 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
419 __func__, dmat, dmat->common.flags, ENOMEM);
423 if (flags & BUS_DMA_ZERO)
425 if (flags & BUS_DMA_NOCACHE)
426 attr = VM_MEMATTR_UNCACHEABLE;
428 attr = VM_MEMATTR_DEFAULT;
431 * Allocate the buffer from the malloc(9) allocator if...
432 * - It's small enough to fit into a single power of two sized bucket.
433 * - The alignment is less than or equal to the maximum size
434 * - The low address requirement is fulfilled.
435 * else allocate non-contiguous pages if...
436 * - The page count that could get allocated doesn't exceed
437 * nsegments also when the maximum segment size is less
439 * - The alignment constraint isn't larger than a page boundary.
440 * - There are no boundary-crossing constraints.
441 * else allocate a block of contiguous pages because one or more of the
442 * constraints is something that only the contig allocator can fulfill.
444 * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
445 * below is just a quick hack. The exact alignment guarantees
446 * of malloc(9) need to be nailed down, and the code below
447 * should be rewritten to take that into account.
449 * In the meantime warn the user if malloc gets it wrong.
451 if ((dmat->common.maxsize <= PAGE_SIZE) &&
452 (dmat->common.alignment <= dmat->common.maxsize) &&
453 dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
454 attr == VM_MEMATTR_DEFAULT) {
455 *vaddr = malloc_domain(dmat->common.maxsize, M_DEVBUF,
456 dmat->common.domain, mflags);
457 } else if (dmat->common.nsegments >=
458 howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
459 dmat->common.alignment <= PAGE_SIZE &&
460 (dmat->common.boundary % PAGE_SIZE) == 0) {
461 /* Page-based multi-segment allocations allowed */
462 *vaddr = (void *)kmem_alloc_attr_domain(dmat->common.domain,
463 dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
465 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
467 *vaddr = (void *)kmem_alloc_contig_domain(dmat->common.domain,
468 dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
469 dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
470 dmat->common.boundary, attr);
471 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
473 if (*vaddr == NULL) {
474 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
475 __func__, dmat, dmat->common.flags, ENOMEM);
477 } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
478 printf("bus_dmamem_alloc failed to align memory properly.\n");
480 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
481 __func__, dmat, dmat->common.flags, 0);
486 * Free a piece of memory and it's allociated dmamap, that was allocated
487 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
490 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
493 * dmamem does not need to be bounced, so the map should be
494 * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
495 * was used and set if kmem_alloc_contig() was used.
498 panic("bus_dmamem_free: Invalid map freed\n");
499 if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
500 free_domain(vaddr, M_DEVBUF);
502 kmem_free(kernel_arena, (vm_offset_t)vaddr,
503 dmat->common.maxsize);
504 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
509 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
510 bus_size_t buflen, int flags)
515 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
517 * Count the number of bounce pages
518 * needed in order to complete this transfer
521 while (buflen != 0) {
522 sgsize = MIN(buflen, dmat->common.maxsegsz);
523 if (bus_dma_run_filter(&dmat->common, curaddr)) {
525 PAGE_SIZE - (curaddr & PAGE_MASK));
531 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
536 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
537 void *buf, bus_size_t buflen, int flags)
540 vm_offset_t vendaddr;
544 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
545 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
546 "alignment= %d", dmat->common.lowaddr,
547 ptoa((vm_paddr_t)Maxmem),
548 dmat->common.boundary, dmat->common.alignment);
549 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
550 map, &nobounce_dmamap, map->pagesneeded);
552 * Count the number of bounce pages
553 * needed in order to complete this transfer
555 vaddr = (vm_offset_t)buf;
556 vendaddr = (vm_offset_t)buf + buflen;
558 while (vaddr < vendaddr) {
559 sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
560 if (pmap == kernel_pmap)
561 paddr = pmap_kextract(vaddr);
563 paddr = pmap_extract(pmap, vaddr);
564 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
565 sg_len = roundup2(sg_len,
566 dmat->common.alignment);
571 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
576 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
577 int ma_offs, bus_size_t buflen, int flags)
579 bus_size_t sg_len, max_sgsize;
583 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
584 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
585 "alignment= %d", dmat->common.lowaddr,
586 ptoa((vm_paddr_t)Maxmem),
587 dmat->common.boundary, dmat->common.alignment);
588 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
589 map, &nobounce_dmamap, map->pagesneeded);
592 * Count the number of bounce pages
593 * needed in order to complete this transfer
597 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
598 sg_len = PAGE_SIZE - ma_offs;
599 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
600 sg_len = MIN(sg_len, max_sgsize);
601 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
602 sg_len = roundup2(sg_len,
603 dmat->common.alignment);
604 sg_len = MIN(sg_len, max_sgsize);
605 KASSERT((sg_len & (dmat->common.alignment - 1))
606 == 0, ("Segment size is not aligned"));
609 if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
611 ma_offs = (ma_offs + sg_len) & PAGE_MASK;
612 KASSERT(buflen >= sg_len,
613 ("Segment length overruns original buffer"));
616 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
621 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
624 /* Reserve Necessary Bounce Pages */
625 mtx_lock(&bounce_lock);
626 if (flags & BUS_DMA_NOWAIT) {
627 if (reserve_bounce_pages(dmat, map, 0) != 0) {
628 mtx_unlock(&bounce_lock);
632 if (reserve_bounce_pages(dmat, map, 1) != 0) {
633 /* Queue us for resources */
634 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
635 mtx_unlock(&bounce_lock);
636 return (EINPROGRESS);
639 mtx_unlock(&bounce_lock);
645 * Add a single contiguous physical range to the segment list.
648 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
649 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
651 bus_addr_t baddr, bmask;
655 * Make sure we don't cross any boundaries.
657 bmask = ~(dmat->common.boundary - 1);
658 if (dmat->common.boundary > 0) {
659 baddr = (curaddr + dmat->common.boundary) & bmask;
660 if (sgsize > (baddr - curaddr))
661 sgsize = (baddr - curaddr);
665 * Insert chunk into a segment, coalescing with
666 * previous segment if possible.
671 segs[seg].ds_addr = curaddr;
672 segs[seg].ds_len = sgsize;
674 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
675 (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
676 (dmat->common.boundary == 0 ||
677 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
678 segs[seg].ds_len += sgsize;
680 if (++seg >= dmat->common.nsegments)
682 segs[seg].ds_addr = curaddr;
683 segs[seg].ds_len = sgsize;
691 * Utility function to load a physical buffer. segp contains
692 * the starting segment on entrace, and the ending segment on exit.
695 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
696 vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
704 map = &nobounce_dmamap;
707 segs = dmat->segments;
709 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
710 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
711 if (map->pagesneeded != 0) {
712 error = _bus_dmamap_reserve_pages(dmat, map, flags);
720 sgsize = MIN(buflen, dmat->common.maxsegsz);
721 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
722 map->pagesneeded != 0 &&
723 bus_dma_run_filter(&dmat->common, curaddr)) {
724 sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
725 curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
728 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
739 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
743 * Utility function to load a linear buffer. segp contains
744 * the starting segment on entrace, and the ending segment on exit.
747 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
748 bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
751 bus_size_t sgsize, max_sgsize;
753 vm_offset_t kvaddr, vaddr;
757 map = &nobounce_dmamap;
760 segs = dmat->segments;
762 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
763 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
764 if (map->pagesneeded != 0) {
765 error = _bus_dmamap_reserve_pages(dmat, map, flags);
771 vaddr = (vm_offset_t)buf;
774 * Get the physical address for this segment.
776 if (pmap == kernel_pmap) {
777 curaddr = pmap_kextract(vaddr);
780 curaddr = pmap_extract(pmap, vaddr);
785 * Compute the segment size, and adjust counts.
787 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
788 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
789 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
790 map->pagesneeded != 0 &&
791 bus_dma_run_filter(&dmat->common, curaddr)) {
792 sgsize = roundup2(sgsize, dmat->common.alignment);
793 sgsize = MIN(sgsize, max_sgsize);
794 curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
797 sgsize = MIN(sgsize, max_sgsize);
799 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
810 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
814 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
815 struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
816 bus_dma_segment_t *segs, int *segp)
818 vm_paddr_t paddr, next_paddr;
819 int error, page_index;
820 bus_size_t sgsize, max_sgsize;
822 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
824 * If we have to keep the offset of each page this function
825 * is not suitable, switch back to bus_dmamap_load_ma_triv
826 * which is going to do the right thing in this case.
828 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
834 map = &nobounce_dmamap;
837 segs = dmat->segments;
839 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
840 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
841 if (map->pagesneeded != 0) {
842 error = _bus_dmamap_reserve_pages(dmat, map, flags);
851 * Compute the segment size, and adjust counts.
853 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
854 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
855 sgsize = PAGE_SIZE - ma_offs;
856 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
857 map->pagesneeded != 0 &&
858 bus_dma_run_filter(&dmat->common, paddr)) {
859 sgsize = roundup2(sgsize, dmat->common.alignment);
860 sgsize = MIN(sgsize, max_sgsize);
861 KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
862 ("Segment size is not aligned"));
864 * Check if two pages of the user provided buffer
867 if ((ma_offs + sgsize) > PAGE_SIZE)
869 VM_PAGE_TO_PHYS(ma[page_index + 1]);
872 paddr = add_bounce_page(dmat, map, 0, paddr,
875 sgsize = MIN(sgsize, max_sgsize);
877 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
881 KASSERT(buflen >= sgsize,
882 ("Segment length overruns original buffer"));
884 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
886 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
892 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
896 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
897 struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
904 map->callback = callback;
905 map->callback_arg = callback_arg;
908 static bus_dma_segment_t *
909 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
910 bus_dma_segment_t *segs, int nsegs, int error)
914 segs = dmat->segments;
919 * Release the mapping held by map.
922 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
924 struct bounce_page *bpage;
929 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
930 STAILQ_REMOVE_HEAD(&map->bpages, links);
931 free_bounce_page(dmat, bpage);
936 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
939 struct bounce_page *bpage;
940 vm_offset_t datavaddr, tempvaddr;
941 bus_size_t datacount1, datacount2;
943 if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
947 * Handle data bouncing. We might also want to add support for
948 * invalidating the caches on broken hardware.
950 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
951 "performing bounce", __func__, dmat, dmat->common.flags, op);
953 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
954 while (bpage != NULL) {
956 datavaddr = bpage->datavaddr;
957 datacount1 = bpage->datacount;
958 if (datavaddr == 0) {
960 pmap_quick_enter_page(bpage->datapage[0]);
961 datavaddr = tempvaddr | bpage->dataoffs;
962 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
966 bcopy((void *)datavaddr,
967 (void *)bpage->vaddr, datacount1);
970 pmap_quick_remove_page(tempvaddr);
972 if (bpage->datapage[1] == 0) {
973 KASSERT(datacount1 == bpage->datacount,
974 ("Mismatch between data size and provided memory space"));
979 * We are dealing with an unmapped buffer that expands
982 datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
983 datacount2 = bpage->datacount - datacount1;
984 bcopy((void *)datavaddr,
985 (void *)(bpage->vaddr + datacount1), datacount2);
986 pmap_quick_remove_page(datavaddr);
989 bpage = STAILQ_NEXT(bpage, links);
991 dmat->bounce_zone->total_bounced++;
994 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
995 while (bpage != NULL) {
997 datavaddr = bpage->datavaddr;
998 datacount1 = bpage->datacount;
999 if (datavaddr == 0) {
1001 pmap_quick_enter_page(bpage->datapage[0]);
1002 datavaddr = tempvaddr | bpage->dataoffs;
1003 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
1007 bcopy((void *)bpage->vaddr, (void *)datavaddr,
1011 pmap_quick_remove_page(tempvaddr);
1013 if (bpage->datapage[1] == 0) {
1014 KASSERT(datacount1 == bpage->datacount,
1015 ("Mismatch between data size and provided memory space"));
1020 * We are dealing with an unmapped buffer that expands
1023 datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1024 datacount2 = bpage->datacount - datacount1;
1025 bcopy((void *)(bpage->vaddr + datacount1),
1026 (void *)datavaddr, datacount2);
1027 pmap_quick_remove_page(datavaddr);
1030 bpage = STAILQ_NEXT(bpage, links);
1032 dmat->bounce_zone->total_bounced++;
1037 init_bounce_pages(void *dummy __unused)
1041 STAILQ_INIT(&bounce_zone_list);
1042 STAILQ_INIT(&bounce_map_waitinglist);
1043 STAILQ_INIT(&bounce_map_callbacklist);
1044 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1046 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1048 static struct sysctl_ctx_list *
1049 busdma_sysctl_tree(struct bounce_zone *bz)
1052 return (&bz->sysctl_tree);
1055 static struct sysctl_oid *
1056 busdma_sysctl_tree_top(struct bounce_zone *bz)
1059 return (bz->sysctl_tree_top);
1063 alloc_bounce_zone(bus_dma_tag_t dmat)
1065 struct bounce_zone *bz;
1067 /* Check to see if we already have a suitable zone */
1068 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1069 if ((dmat->common.alignment <= bz->alignment) &&
1070 (dmat->common.lowaddr >= bz->lowaddr) &&
1071 (dmat->common.domain == bz->domain)) {
1072 dmat->bounce_zone = bz;
1077 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1078 M_NOWAIT | M_ZERO)) == NULL)
1081 STAILQ_INIT(&bz->bounce_page_list);
1082 bz->free_bpages = 0;
1083 bz->reserved_bpages = 0;
1084 bz->active_bpages = 0;
1085 bz->lowaddr = dmat->common.lowaddr;
1086 bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1088 bz->domain = dmat->common.domain;
1089 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1091 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1092 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1093 dmat->bounce_zone = bz;
1095 sysctl_ctx_init(&bz->sysctl_tree);
1096 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1097 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1099 if (bz->sysctl_tree_top == NULL) {
1100 sysctl_ctx_free(&bz->sysctl_tree);
1101 return (0); /* XXX error code? */
1104 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1105 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1106 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1107 "Total bounce pages");
1108 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1109 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1110 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1111 "Free bounce pages");
1112 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1113 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1114 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1115 "Reserved bounce pages");
1116 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1117 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1118 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1119 "Active bounce pages");
1120 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1121 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1122 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1123 "Total bounce requests");
1124 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1125 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1126 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1127 "Total bounce requests that were deferred");
1128 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1129 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1130 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1131 SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1132 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1133 "alignment", CTLFLAG_RD, &bz->alignment, "");
1134 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1135 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1136 "domain", CTLFLAG_RD, &bz->domain, 0,
1143 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1145 struct bounce_zone *bz;
1148 bz = dmat->bounce_zone;
1150 while (numpages > 0) {
1151 struct bounce_page *bpage;
1153 bpage = (struct bounce_page *)malloc_domain(sizeof(*bpage),
1154 M_DEVBUF, dmat->common.domain, M_NOWAIT | M_ZERO);
1158 bpage->vaddr = (vm_offset_t)contigmalloc_domain(PAGE_SIZE,
1159 M_DEVBUF, dmat->common.domain, M_NOWAIT, 0ul,
1160 bz->lowaddr, PAGE_SIZE, 0);
1161 if (bpage->vaddr == 0) {
1162 free_domain(bpage, M_DEVBUF);
1165 bpage->busaddr = pmap_kextract(bpage->vaddr);
1166 mtx_lock(&bounce_lock);
1167 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1171 mtx_unlock(&bounce_lock);
1179 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1181 struct bounce_zone *bz;
1184 mtx_assert(&bounce_lock, MA_OWNED);
1185 bz = dmat->bounce_zone;
1186 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1187 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1188 return (map->pagesneeded - (map->pagesreserved + pages));
1189 bz->free_bpages -= pages;
1190 bz->reserved_bpages += pages;
1191 map->pagesreserved += pages;
1192 pages = map->pagesneeded - map->pagesreserved;
1198 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1199 bus_addr_t addr1, bus_addr_t addr2, bus_size_t size)
1201 struct bounce_zone *bz;
1202 struct bounce_page *bpage;
1204 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1205 KASSERT(map != NULL && map != &nobounce_dmamap,
1206 ("add_bounce_page: bad map %p", map));
1208 bz = dmat->bounce_zone;
1209 if (map->pagesneeded == 0)
1210 panic("add_bounce_page: map doesn't need any pages");
1213 if (map->pagesreserved == 0)
1214 panic("add_bounce_page: map doesn't need any pages");
1215 map->pagesreserved--;
1217 mtx_lock(&bounce_lock);
1218 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1220 panic("add_bounce_page: free page list is empty");
1222 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1223 bz->reserved_bpages--;
1224 bz->active_bpages++;
1225 mtx_unlock(&bounce_lock);
1227 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1228 /* Page offset needs to be preserved. */
1229 bpage->vaddr |= addr1 & PAGE_MASK;
1230 bpage->busaddr |= addr1 & PAGE_MASK;
1232 ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1234 bpage->datavaddr = vaddr;
1235 bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1236 KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1237 bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1238 bpage->dataoffs = addr1 & PAGE_MASK;
1239 bpage->datacount = size;
1240 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1241 return (bpage->busaddr);
1245 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1247 struct bus_dmamap *map;
1248 struct bounce_zone *bz;
1250 bz = dmat->bounce_zone;
1251 bpage->datavaddr = 0;
1252 bpage->datacount = 0;
1253 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1255 * Reset the bounce page to start at offset 0. Other uses
1256 * of this bounce page may need to store a full page of
1257 * data and/or assume it starts on a page boundary.
1259 bpage->vaddr &= ~PAGE_MASK;
1260 bpage->busaddr &= ~PAGE_MASK;
1263 mtx_lock(&bounce_lock);
1264 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1266 bz->active_bpages--;
1267 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1268 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1269 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1270 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1272 busdma_swi_pending = 1;
1273 bz->total_deferred++;
1274 swi_sched(vm_ih, 0);
1277 mtx_unlock(&bounce_lock);
1284 struct bus_dmamap *map;
1286 mtx_lock(&bounce_lock);
1287 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1288 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1289 mtx_unlock(&bounce_lock);
1291 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1292 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1293 map->callback, map->callback_arg, BUS_DMA_WAITOK);
1294 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1296 mtx_lock(&bounce_lock);
1298 mtx_unlock(&bounce_lock);
1301 struct bus_dma_impl bus_dma_bounce_impl = {
1302 .tag_create = bounce_bus_dma_tag_create,
1303 .tag_destroy = bounce_bus_dma_tag_destroy,
1304 .tag_set_domain = bounce_bus_dma_tag_set_domain,
1305 .map_create = bounce_bus_dmamap_create,
1306 .map_destroy = bounce_bus_dmamap_destroy,
1307 .mem_alloc = bounce_bus_dmamem_alloc,
1308 .mem_free = bounce_bus_dmamem_free,
1309 .load_phys = bounce_bus_dmamap_load_phys,
1310 .load_buffer = bounce_bus_dmamap_load_buffer,
1311 .load_ma = bounce_bus_dmamap_load_ma,
1312 .map_waitok = bounce_bus_dmamap_waitok,
1313 .map_complete = bounce_bus_dmamap_complete,
1314 .map_unload = bounce_bus_dmamap_unload,
1315 .map_sync = bounce_bus_dmamap_sync,