2 * Copyright (c) 1997, 1998 Justin T. Gibbs.
3 * Copyright (c) 2015-2016 The FreeBSD Foundation
6 * Portions of this software were developed by Andrew Turner
7 * under sponsorship of the FreeBSD Foundation.
9 * Portions of this software were developed by Semihalf
10 * under sponsorship of the FreeBSD Foundation.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification, immediately at the beginning of the file.
18 * 2. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
25 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
41 #include <sys/interrupt.h>
42 #include <sys/kernel.h>
46 #include <sys/memdesc.h>
47 #include <sys/mutex.h>
48 #include <sys/sysctl.h>
52 #include <vm/vm_extern.h>
53 #include <vm/vm_kern.h>
54 #include <vm/vm_page.h>
55 #include <vm/vm_map.h>
57 #include <machine/atomic.h>
58 #include <machine/bus.h>
59 #include <machine/md_var.h>
60 #include <arm64/include/bus_dma_impl.h>
62 #define MAX_BPAGES 4096
65 BF_COULD_BOUNCE = 0x01,
66 BF_MIN_ALLOC_COMP = 0x02,
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_page_t datapage; /* physical page of client data */
86 vm_offset_t dataoffs; /* page offset 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;
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 | CTLFLAG_MPSAFE, 0,
117 "Busdma parameters");
118 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
119 "Total bounce pages");
122 vm_offset_t vaddr; /* kva of client data */
123 bus_addr_t paddr; /* physical address */
124 vm_page_t pages; /* starting page of client data */
125 bus_size_t datacount; /* client data count */
129 struct bp_list bpages;
134 bus_dmamap_callback_t *callback;
136 STAILQ_ENTRY(bus_dmamap) links;
138 #define DMAMAP_COULD_BOUNCE (1 << 0)
139 #define DMAMAP_FROM_DMAMEM (1 << 1)
141 struct sync_list slist[];
144 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
145 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
147 static void init_bounce_pages(void *dummy);
148 static int alloc_bounce_zone(bus_dma_tag_t dmat);
149 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
150 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
152 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
153 vm_offset_t vaddr, bus_addr_t addr, bus_size_t size);
154 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
155 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
156 static bool _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf,
157 bus_size_t buflen, int *pagesneeded);
158 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
159 pmap_t pmap, void *buf, bus_size_t buflen, int flags);
160 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
161 vm_paddr_t buf, bus_size_t buflen, int flags);
162 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
166 * Allocate a device specific dma_tag.
169 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
170 bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
171 bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
172 int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
173 void *lockfuncarg, bus_dma_tag_t *dmat)
175 bus_dma_tag_t newtag;
179 error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
180 NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
181 maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
182 sizeof (struct bus_dma_tag), (void **)&newtag);
186 newtag->common.impl = &bus_dma_bounce_impl;
187 newtag->map_count = 0;
188 newtag->segments = NULL;
190 if ((flags & BUS_DMA_COHERENT) != 0)
191 newtag->bounce_flags |= BF_COHERENT;
193 if (parent != NULL) {
194 if ((newtag->common.filter != NULL ||
195 (parent->bounce_flags & BF_COULD_BOUNCE) != 0))
196 newtag->bounce_flags |= BF_COULD_BOUNCE;
198 /* Copy some flags from the parent */
199 newtag->bounce_flags |= parent->bounce_flags & BF_COHERENT;
202 if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
203 newtag->common.alignment > 1)
204 newtag->bounce_flags |= BF_COULD_BOUNCE;
206 if (((newtag->bounce_flags & BF_COULD_BOUNCE) != 0) &&
207 (flags & BUS_DMA_ALLOCNOW) != 0) {
208 struct bounce_zone *bz;
211 if ((error = alloc_bounce_zone(newtag)) != 0) {
212 free(newtag, M_DEVBUF);
215 bz = newtag->bounce_zone;
217 if (ptoa(bz->total_bpages) < maxsize) {
220 pages = atop(round_page(maxsize)) - bz->total_bpages;
222 /* Add pages to our bounce pool */
223 if (alloc_bounce_pages(newtag, pages) < pages)
226 /* Performed initial allocation */
227 newtag->bounce_flags |= BF_MIN_ALLOC_COMP;
232 free(newtag, M_DEVBUF);
235 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
236 __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
242 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
244 bus_dma_tag_t dmat_copy, parent;
251 if (dmat->map_count != 0) {
255 while (dmat != NULL) {
256 parent = (bus_dma_tag_t)dmat->common.parent;
257 atomic_subtract_int(&dmat->common.ref_count, 1);
258 if (dmat->common.ref_count == 0) {
259 if (dmat->segments != NULL)
260 free(dmat->segments, M_DEVBUF);
261 free(dmat, M_DEVBUF);
263 * Last reference count, so
264 * release our reference
265 * count on our parent.
273 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
278 bounce_bus_dma_id_mapped(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen)
281 if ((dmat->bounce_flags & BF_COULD_BOUNCE) == 0)
283 return (!_bus_dmamap_pagesneeded(dmat, buf, buflen, NULL));
287 alloc_dmamap(bus_dma_tag_t dmat, int flags)
292 mapsize = sizeof(*map);
293 mapsize += sizeof(struct sync_list) * dmat->common.nsegments;
294 map = malloc(mapsize, M_DEVBUF, flags | M_ZERO);
298 /* Initialize the new map */
299 STAILQ_INIT(&map->bpages);
305 * Allocate a handle for mapping from kva/uva/physical
306 * address space into bus device space.
309 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
311 struct bounce_zone *bz;
312 int error, maxpages, pages;
316 if (dmat->segments == NULL) {
317 dmat->segments = (bus_dma_segment_t *)malloc(
318 sizeof(bus_dma_segment_t) * dmat->common.nsegments,
320 if (dmat->segments == NULL) {
321 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
322 __func__, dmat, ENOMEM);
327 *mapp = alloc_dmamap(dmat, M_NOWAIT);
329 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
330 __func__, dmat, ENOMEM);
335 * Bouncing might be required if the driver asks for an active
336 * exclusion region, a data alignment that is stricter than 1, and/or
337 * an active address boundary.
339 if (dmat->bounce_flags & BF_COULD_BOUNCE) {
341 if (dmat->bounce_zone == NULL) {
342 if ((error = alloc_bounce_zone(dmat)) != 0) {
343 free(*mapp, M_DEVBUF);
347 bz = dmat->bounce_zone;
349 (*mapp)->flags = DMAMAP_COULD_BOUNCE;
352 * Attempt to add pages to our pool on a per-instance
353 * basis up to a sane limit.
355 if (dmat->common.alignment > 1)
356 maxpages = MAX_BPAGES;
358 maxpages = MIN(MAX_BPAGES, Maxmem -
359 atop(dmat->common.lowaddr));
360 if ((dmat->bounce_flags & BF_MIN_ALLOC_COMP) == 0 ||
361 (bz->map_count > 0 && bz->total_bpages < maxpages)) {
362 pages = MAX(atop(dmat->common.maxsize), 1);
363 pages = MIN(maxpages - bz->total_bpages, pages);
364 pages = MAX(pages, 1);
365 if (alloc_bounce_pages(dmat, pages) < pages)
367 if ((dmat->bounce_flags & BF_MIN_ALLOC_COMP)
370 dmat->bounce_flags |=
381 free(*mapp, M_DEVBUF);
382 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
383 __func__, dmat, dmat->common.flags, error);
388 * Destroy a handle for mapping from kva/uva/physical
389 * address space into bus device space.
392 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
395 /* Check we are destroying the correct map type */
396 if ((map->flags & DMAMAP_FROM_DMAMEM) != 0)
397 panic("bounce_bus_dmamap_destroy: Invalid map freed\n");
399 if (STAILQ_FIRST(&map->bpages) != NULL || map->sync_count != 0) {
400 CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, EBUSY);
403 if (dmat->bounce_zone) {
404 KASSERT((map->flags & DMAMAP_COULD_BOUNCE) != 0,
405 ("%s: Bounce zone when cannot bounce", __func__));
406 dmat->bounce_zone->map_count--;
410 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
416 * Allocate a piece of memory that can be efficiently mapped into
417 * bus device space based on the constraints lited in the dma tag.
418 * A dmamap to for use with dmamap_load is also allocated.
421 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
426 * This bus_dma implementation requires IO-Coherent architecutre.
427 * If IO-Coherency is not guaranteed, the BUS_DMA_COHERENT flag has
428 * to be implented using non-cacheable memory.
434 if (flags & BUS_DMA_NOWAIT)
439 if (dmat->segments == NULL) {
440 dmat->segments = (bus_dma_segment_t *)malloc(
441 sizeof(bus_dma_segment_t) * dmat->common.nsegments,
443 if (dmat->segments == NULL) {
444 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
445 __func__, dmat, dmat->common.flags, ENOMEM);
449 if (flags & BUS_DMA_ZERO)
451 if (flags & BUS_DMA_NOCACHE)
452 attr = VM_MEMATTR_UNCACHEABLE;
453 else if ((flags & BUS_DMA_COHERENT) != 0 &&
454 (dmat->bounce_flags & BF_COHERENT) == 0)
456 * If we have a non-coherent tag, and are trying to allocate
457 * a coherent block of memory it needs to be uncached.
459 attr = VM_MEMATTR_UNCACHEABLE;
461 attr = VM_MEMATTR_DEFAULT;
464 * Create the map, but don't set the could bounce flag as
465 * this allocation should never bounce;
467 *mapp = alloc_dmamap(dmat, mflags);
469 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
470 __func__, dmat, dmat->common.flags, ENOMEM);
473 (*mapp)->flags = DMAMAP_FROM_DMAMEM;
476 * Allocate the buffer from the malloc(9) allocator if...
477 * - It's small enough to fit into a single power of two sized bucket.
478 * - The alignment is less than or equal to the maximum size
479 * - The low address requirement is fulfilled.
480 * else allocate non-contiguous pages if...
481 * - The page count that could get allocated doesn't exceed
482 * nsegments also when the maximum segment size is less
484 * - The alignment constraint isn't larger than a page boundary.
485 * - There are no boundary-crossing constraints.
486 * else allocate a block of contiguous pages because one or more of the
487 * constraints is something that only the contig allocator can fulfill.
489 * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
490 * below is just a quick hack. The exact alignment guarantees
491 * of malloc(9) need to be nailed down, and the code below
492 * should be rewritten to take that into account.
494 * In the meantime warn the user if malloc gets it wrong.
496 if ((dmat->common.maxsize <= PAGE_SIZE) &&
497 (dmat->common.alignment <= dmat->common.maxsize) &&
498 dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
499 attr == VM_MEMATTR_DEFAULT) {
500 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
501 } else if (dmat->common.nsegments >=
502 howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
503 dmat->common.alignment <= PAGE_SIZE &&
504 (dmat->common.boundary % PAGE_SIZE) == 0) {
505 /* Page-based multi-segment allocations allowed */
506 *vaddr = (void *)kmem_alloc_attr(dmat->common.maxsize, mflags,
507 0ul, dmat->common.lowaddr, attr);
508 dmat->bounce_flags |= BF_KMEM_ALLOC;
510 *vaddr = (void *)kmem_alloc_contig(dmat->common.maxsize, mflags,
511 0ul, dmat->common.lowaddr, dmat->common.alignment != 0 ?
512 dmat->common.alignment : 1ul, dmat->common.boundary, attr);
513 dmat->bounce_flags |= BF_KMEM_ALLOC;
515 if (*vaddr == NULL) {
516 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
517 __func__, dmat, dmat->common.flags, ENOMEM);
518 free(*mapp, M_DEVBUF);
520 } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
521 printf("bus_dmamem_alloc failed to align memory properly.\n");
524 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
525 __func__, dmat, dmat->common.flags, 0);
530 * Free a piece of memory and it's allociated dmamap, that was allocated
531 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
534 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
538 * Check the map came from bounce_bus_dmamem_alloc, so the map
539 * should be NULL and the BF_KMEM_ALLOC flag cleared if malloc()
540 * was used and set if kmem_alloc_contig() was used.
542 if ((map->flags & DMAMAP_FROM_DMAMEM) == 0)
543 panic("bus_dmamem_free: Invalid map freed\n");
544 if ((dmat->bounce_flags & BF_KMEM_ALLOC) == 0)
545 free(vaddr, M_DEVBUF);
547 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
550 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
555 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
563 * Count the number of bounce pages needed in order to
564 * complete this transfer
568 while (buflen != 0) {
569 sgsize = MIN(buflen, dmat->common.maxsegsz);
570 if (bus_dma_run_filter(&dmat->common, curaddr)) {
572 PAGE_SIZE - (curaddr & PAGE_MASK));
573 if (pagesneeded == NULL)
581 if (pagesneeded != NULL)
582 *pagesneeded = count;
587 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
588 bus_size_t buflen, int flags)
591 if ((map->flags & DMAMAP_COULD_BOUNCE) != 0 && map->pagesneeded == 0) {
592 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
593 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
598 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
599 void *buf, bus_size_t buflen, int flags)
602 vm_offset_t vendaddr;
606 if ((map->flags & DMAMAP_COULD_BOUNCE) != 0 && 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 CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d", map,
614 * Count the number of bounce pages
615 * needed in order to complete this transfer
617 vaddr = (vm_offset_t)buf;
618 vendaddr = (vm_offset_t)buf + buflen;
620 while (vaddr < vendaddr) {
621 sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
622 if (pmap == kernel_pmap)
623 paddr = pmap_kextract(vaddr);
625 paddr = pmap_extract(pmap, vaddr);
626 if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
627 sg_len = roundup2(sg_len,
628 dmat->common.alignment);
633 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
638 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
641 /* Reserve Necessary Bounce Pages */
642 mtx_lock(&bounce_lock);
643 if (flags & BUS_DMA_NOWAIT) {
644 if (reserve_bounce_pages(dmat, map, 0) != 0) {
645 mtx_unlock(&bounce_lock);
649 if (reserve_bounce_pages(dmat, map, 1) != 0) {
650 /* Queue us for resources */
651 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
652 mtx_unlock(&bounce_lock);
653 return (EINPROGRESS);
656 mtx_unlock(&bounce_lock);
662 * Add a single contiguous physical range to the segment list.
665 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
666 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
668 bus_addr_t baddr, bmask;
672 * Make sure we don't cross any boundaries.
674 bmask = ~(dmat->common.boundary - 1);
675 if (dmat->common.boundary > 0) {
676 baddr = (curaddr + dmat->common.boundary) & bmask;
677 if (sgsize > (baddr - curaddr))
678 sgsize = (baddr - curaddr);
682 * Insert chunk into a segment, coalescing with
683 * previous segment if possible.
688 segs[seg].ds_addr = curaddr;
689 segs[seg].ds_len = sgsize;
691 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
692 (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
693 (dmat->common.boundary == 0 ||
694 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
695 segs[seg].ds_len += sgsize;
697 if (++seg >= dmat->common.nsegments)
699 segs[seg].ds_addr = curaddr;
700 segs[seg].ds_len = sgsize;
708 * Utility function to load a physical buffer. segp contains
709 * the starting segment on entrace, and the ending segment on exit.
712 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
713 vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
716 struct sync_list *sl;
718 bus_addr_t curaddr, sl_end;
722 segs = dmat->segments;
724 if ((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) {
725 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
726 if (map->pagesneeded != 0) {
727 error = _bus_dmamap_reserve_pages(dmat, map, flags);
733 sl = map->slist + map->sync_count - 1;
738 sgsize = MIN(buflen, dmat->common.maxsegsz);
739 if (((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) &&
740 map->pagesneeded != 0 &&
741 bus_dma_run_filter(&dmat->common, curaddr)) {
742 sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
743 curaddr = add_bounce_page(dmat, map, 0, curaddr,
745 } else if ((dmat->bounce_flags & BF_COHERENT) == 0) {
746 if (map->sync_count > 0)
747 sl_end = sl->paddr + sl->datacount;
749 if (map->sync_count == 0 || curaddr != sl_end) {
750 if (++map->sync_count > dmat->common.nsegments)
755 sl->datacount = sgsize;
756 sl->pages = PHYS_TO_VM_PAGE(curaddr);
757 KASSERT(sl->pages != NULL,
758 ("%s: page at PA:0x%08lx is not in "
759 "vm_page_array", __func__, curaddr));
761 sl->datacount += sgsize;
763 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
774 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
778 * Utility function to load a linear buffer. segp contains
779 * the starting segment on entrace, and the ending segment on exit.
782 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
783 bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
786 struct sync_list *sl;
787 bus_size_t sgsize, max_sgsize;
788 bus_addr_t curaddr, sl_pend;
789 vm_offset_t kvaddr, vaddr, sl_vend;
793 segs = dmat->segments;
795 if ((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) {
796 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
797 if (map->pagesneeded != 0) {
798 error = _bus_dmamap_reserve_pages(dmat, map, flags);
804 sl = map->slist + map->sync_count - 1;
805 vaddr = (vm_offset_t)buf;
811 * Get the physical address for this segment.
813 if (pmap == kernel_pmap) {
814 curaddr = pmap_kextract(vaddr);
817 curaddr = pmap_extract(pmap, vaddr);
822 * Compute the segment size, and adjust counts.
824 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
825 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
826 if (((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) &&
827 map->pagesneeded != 0 &&
828 bus_dma_run_filter(&dmat->common, curaddr)) {
829 sgsize = roundup2(sgsize, dmat->common.alignment);
830 sgsize = MIN(sgsize, max_sgsize);
831 curaddr = add_bounce_page(dmat, map, kvaddr, curaddr,
833 } else if ((dmat->bounce_flags & BF_COHERENT) == 0) {
834 sgsize = MIN(sgsize, max_sgsize);
835 if (map->sync_count > 0) {
836 sl_pend = sl->paddr + sl->datacount;
837 sl_vend = sl->vaddr + sl->datacount;
840 if (map->sync_count == 0 ||
841 (kvaddr != 0 && kvaddr != sl_vend) ||
842 (curaddr != sl_pend)) {
844 if (++map->sync_count > dmat->common.nsegments)
852 sl->pages = PHYS_TO_VM_PAGE(curaddr);
853 KASSERT(sl->pages != NULL,
854 ("%s: page at PA:0x%08lx is not "
855 "in vm_page_array", __func__,
858 sl->datacount = sgsize;
860 sl->datacount += sgsize;
862 sgsize = MIN(sgsize, max_sgsize);
864 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
876 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
880 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
881 struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
884 if ((map->flags & DMAMAP_COULD_BOUNCE) == 0)
888 map->callback = callback;
889 map->callback_arg = callback_arg;
892 static bus_dma_segment_t *
893 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
894 bus_dma_segment_t *segs, int nsegs, int error)
898 segs = dmat->segments;
903 * Release the mapping held by map.
906 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
908 struct bounce_page *bpage;
910 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
911 STAILQ_REMOVE_HEAD(&map->bpages, links);
912 free_bounce_page(dmat, bpage);
919 dma_preread_safe(vm_offset_t va, vm_size_t size)
922 * Write back any partial cachelines immediately before and
923 * after the DMA region.
925 if (va & (dcache_line_size - 1))
926 cpu_dcache_wb_range(va, 1);
927 if ((va + size) & (dcache_line_size - 1))
928 cpu_dcache_wb_range(va + size, 1);
930 cpu_dcache_inv_range(va, size);
934 dma_dcache_sync(struct sync_list *sl, bus_dmasync_op_t op)
936 uint32_t len, offset;
939 vm_offset_t va, tempva;
942 offset = sl->paddr & PAGE_MASK;
944 size = sl->datacount;
947 for ( ; size != 0; size -= len, pa += len, offset = 0, ++m) {
949 if (sl->vaddr == 0) {
950 len = min(PAGE_SIZE - offset, size);
951 tempva = pmap_quick_enter_page(m);
952 va = tempva | offset;
953 KASSERT(pa == (VM_PAGE_TO_PHYS(m) | offset),
954 ("unexpected vm_page_t phys: 0x%16lx != 0x%16lx",
955 VM_PAGE_TO_PHYS(m) | offset, pa));
962 case BUS_DMASYNC_PREWRITE:
963 case BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD:
964 cpu_dcache_wb_range(va, len);
966 case BUS_DMASYNC_PREREAD:
968 * An mbuf may start in the middle of a cacheline. There
969 * will be no cpu writes to the beginning of that line
970 * (which contains the mbuf header) while dma is in
971 * progress. Handle that case by doing a writeback of
972 * just the first cacheline before invalidating the
973 * overall buffer. Any mbuf in a chain may have this
974 * misalignment. Buffers which are not mbufs bounce if
975 * they are not aligned to a cacheline.
977 dma_preread_safe(va, len);
979 case BUS_DMASYNC_POSTREAD:
980 case BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE:
981 cpu_dcache_inv_range(va, len);
984 panic("unsupported combination of sync operations: "
989 pmap_quick_remove_page(tempva);
994 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
997 struct bounce_page *bpage;
998 struct sync_list *sl, *end;
999 vm_offset_t datavaddr, tempvaddr;
1001 if (op == BUS_DMASYNC_POSTWRITE)
1004 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1006 * Wait for any DMA operations to complete before the bcopy.
1011 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1012 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
1013 "performing bounce", __func__, dmat, dmat->common.flags,
1016 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
1017 while (bpage != NULL) {
1019 datavaddr = bpage->datavaddr;
1020 if (datavaddr == 0) {
1021 tempvaddr = pmap_quick_enter_page(
1023 datavaddr = tempvaddr | bpage->dataoffs;
1026 bcopy((void *)datavaddr,
1027 (void *)bpage->vaddr, bpage->datacount);
1029 pmap_quick_remove_page(tempvaddr);
1030 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1031 cpu_dcache_wb_range(bpage->vaddr,
1033 bpage = STAILQ_NEXT(bpage, links);
1035 dmat->bounce_zone->total_bounced++;
1036 } else if ((op & BUS_DMASYNC_PREREAD) != 0) {
1037 while (bpage != NULL) {
1038 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1039 cpu_dcache_wbinv_range(bpage->vaddr,
1041 bpage = STAILQ_NEXT(bpage, links);
1045 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1046 while (bpage != NULL) {
1047 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1048 cpu_dcache_inv_range(bpage->vaddr,
1051 datavaddr = bpage->datavaddr;
1052 if (datavaddr == 0) {
1053 tempvaddr = pmap_quick_enter_page(
1055 datavaddr = tempvaddr | bpage->dataoffs;
1058 bcopy((void *)bpage->vaddr,
1059 (void *)datavaddr, bpage->datacount);
1062 pmap_quick_remove_page(tempvaddr);
1063 bpage = STAILQ_NEXT(bpage, links);
1065 dmat->bounce_zone->total_bounced++;
1070 * Cache maintenance for normal (non-COHERENT non-bounce) buffers.
1072 if (map->sync_count != 0) {
1073 sl = &map->slist[0];
1074 end = &map->slist[map->sync_count];
1075 CTR3(KTR_BUSDMA, "%s: tag %p op 0x%x "
1076 "performing sync", __func__, dmat, op);
1078 for ( ; sl != end; ++sl)
1079 dma_dcache_sync(sl, op);
1082 if ((op & (BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE)) != 0) {
1084 * Wait for the bcopy to complete before any DMA operations.
1091 init_bounce_pages(void *dummy __unused)
1095 STAILQ_INIT(&bounce_zone_list);
1096 STAILQ_INIT(&bounce_map_waitinglist);
1097 STAILQ_INIT(&bounce_map_callbacklist);
1098 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1100 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1102 static struct sysctl_ctx_list *
1103 busdma_sysctl_tree(struct bounce_zone *bz)
1106 return (&bz->sysctl_tree);
1109 static struct sysctl_oid *
1110 busdma_sysctl_tree_top(struct bounce_zone *bz)
1113 return (bz->sysctl_tree_top);
1117 alloc_bounce_zone(bus_dma_tag_t dmat)
1119 struct bounce_zone *bz;
1121 /* Check to see if we already have a suitable zone */
1122 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1123 if ((dmat->common.alignment <= bz->alignment) &&
1124 (dmat->common.lowaddr >= bz->lowaddr)) {
1125 dmat->bounce_zone = bz;
1130 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1131 M_NOWAIT | M_ZERO)) == NULL)
1134 STAILQ_INIT(&bz->bounce_page_list);
1135 bz->free_bpages = 0;
1136 bz->reserved_bpages = 0;
1137 bz->active_bpages = 0;
1138 bz->lowaddr = dmat->common.lowaddr;
1139 bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1141 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1143 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1144 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1145 dmat->bounce_zone = bz;
1147 sysctl_ctx_init(&bz->sysctl_tree);
1148 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1149 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1150 CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
1151 if (bz->sysctl_tree_top == NULL) {
1152 sysctl_ctx_free(&bz->sysctl_tree);
1153 return (0); /* XXX error code? */
1156 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1157 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1158 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1159 "Total bounce pages");
1160 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1161 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1162 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1163 "Free bounce pages");
1164 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1165 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1166 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1167 "Reserved bounce pages");
1168 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1169 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1170 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1171 "Active bounce pages");
1172 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1173 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1174 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1175 "Total bounce requests");
1176 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1177 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1178 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1179 "Total bounce requests that were deferred");
1180 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1181 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1182 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1183 SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1184 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1185 "alignment", CTLFLAG_RD, &bz->alignment, "");
1191 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1193 struct bounce_zone *bz;
1196 bz = dmat->bounce_zone;
1198 while (numpages > 0) {
1199 struct bounce_page *bpage;
1201 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1206 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1207 M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
1208 if (bpage->vaddr == 0) {
1209 free(bpage, M_DEVBUF);
1212 bpage->busaddr = pmap_kextract(bpage->vaddr);
1213 mtx_lock(&bounce_lock);
1214 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1218 mtx_unlock(&bounce_lock);
1226 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1228 struct bounce_zone *bz;
1231 mtx_assert(&bounce_lock, MA_OWNED);
1232 bz = dmat->bounce_zone;
1233 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1234 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1235 return (map->pagesneeded - (map->pagesreserved + pages));
1236 bz->free_bpages -= pages;
1237 bz->reserved_bpages += pages;
1238 map->pagesreserved += pages;
1239 pages = map->pagesneeded - map->pagesreserved;
1245 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1246 bus_addr_t addr, bus_size_t size)
1248 struct bounce_zone *bz;
1249 struct bounce_page *bpage;
1251 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1252 KASSERT((map->flags & DMAMAP_COULD_BOUNCE) != 0,
1253 ("add_bounce_page: bad map %p", map));
1255 bz = dmat->bounce_zone;
1256 if (map->pagesneeded == 0)
1257 panic("add_bounce_page: map doesn't need any pages");
1260 if (map->pagesreserved == 0)
1261 panic("add_bounce_page: map doesn't need any pages");
1262 map->pagesreserved--;
1264 mtx_lock(&bounce_lock);
1265 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1267 panic("add_bounce_page: free page list is empty");
1269 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1270 bz->reserved_bpages--;
1271 bz->active_bpages++;
1272 mtx_unlock(&bounce_lock);
1274 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1275 /* Page offset needs to be preserved. */
1276 bpage->vaddr |= addr & PAGE_MASK;
1277 bpage->busaddr |= addr & PAGE_MASK;
1279 bpage->datavaddr = vaddr;
1280 bpage->datapage = PHYS_TO_VM_PAGE(addr);
1281 bpage->dataoffs = addr & PAGE_MASK;
1282 bpage->datacount = size;
1283 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1284 return (bpage->busaddr);
1288 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1290 struct bus_dmamap *map;
1291 struct bounce_zone *bz;
1293 bz = dmat->bounce_zone;
1294 bpage->datavaddr = 0;
1295 bpage->datacount = 0;
1296 if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1298 * Reset the bounce page to start at offset 0. Other uses
1299 * of this bounce page may need to store a full page of
1300 * data and/or assume it starts on a page boundary.
1302 bpage->vaddr &= ~PAGE_MASK;
1303 bpage->busaddr &= ~PAGE_MASK;
1306 mtx_lock(&bounce_lock);
1307 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1309 bz->active_bpages--;
1310 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1311 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1312 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1313 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1315 busdma_swi_pending = 1;
1316 bz->total_deferred++;
1317 swi_sched(vm_ih, 0);
1320 mtx_unlock(&bounce_lock);
1327 struct bus_dmamap *map;
1329 mtx_lock(&bounce_lock);
1330 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1331 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1332 mtx_unlock(&bounce_lock);
1334 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1335 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1336 map->callback, map->callback_arg, BUS_DMA_WAITOK);
1337 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1339 mtx_lock(&bounce_lock);
1341 mtx_unlock(&bounce_lock);
1344 struct bus_dma_impl bus_dma_bounce_impl = {
1345 .tag_create = bounce_bus_dma_tag_create,
1346 .tag_destroy = bounce_bus_dma_tag_destroy,
1347 .id_mapped = bounce_bus_dma_id_mapped,
1348 .map_create = bounce_bus_dmamap_create,
1349 .map_destroy = bounce_bus_dmamap_destroy,
1350 .mem_alloc = bounce_bus_dmamem_alloc,
1351 .mem_free = bounce_bus_dmamem_free,
1352 .load_phys = bounce_bus_dmamap_load_phys,
1353 .load_buffer = bounce_bus_dmamap_load_buffer,
1354 .load_ma = bus_dmamap_load_ma_triv,
1355 .map_waitok = bounce_bus_dmamap_waitok,
1356 .map_complete = bounce_bus_dmamap_complete,
1357 .map_unload = bounce_bus_dmamap_unload,
1358 .map_sync = bounce_bus_dmamap_sync