2 * Copyright (c) 2012 Ian Lepore
3 * Copyright (c) 2004 Olivier Houchard
4 * Copyright (c) 2002 Peter Grehan
5 * Copyright (c) 1997, 1998 Justin T. Gibbs.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions, and the following disclaimer,
13 * without modification, immediately at the beginning of the file.
14 * 2. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * From i386/busdma_machdep.c,v 1.26 2002/04/19 22:58:09 alfred
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
36 * ARM bus dma support routines.
38 * XXX Things to investigate / fix some day...
39 * - What is the earliest that this API can be called? Could there be any
40 * fallout from changing the SYSINIT() order from SI_SUB_VM to SI_SUB_KMEM?
41 * - The manpage mentions the BUS_DMA_NOWAIT flag only in the context of the
42 * bus_dmamap_load() function. This code has historically (and still does)
43 * honor it in bus_dmamem_alloc(). If we got rid of that we could lose some
44 * error checking because some resource management calls would become WAITOK
45 * and thus "cannot fail."
46 * - The decisions made by _bus_dma_can_bounce() should be made once, at tag
47 * creation time, and the result stored in the tag.
48 * - It should be possible to take some shortcuts when mapping a buffer we know
49 * came from the uma(9) allocators based on what we know about such buffers
50 * (aligned, contiguous, etc).
51 * - The allocation of bounce pages could probably be cleaned up, then we could
52 * retire arm_remap_nocache().
55 #define _ARM32_BUS_DMA_PRIVATE
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/malloc.h>
60 #include <sys/busdma_bufalloc.h>
61 #include <sys/counter.h>
62 #include <sys/interrupt.h>
63 #include <sys/kernel.h>
66 #include <sys/memdesc.h>
68 #include <sys/mutex.h>
69 #include <sys/sysctl.h>
73 #include <vm/vm_param.h>
74 #include <vm/vm_page.h>
75 #include <vm/vm_phys.h>
76 #include <vm/vm_map.h>
77 #include <vm/vm_extern.h>
78 #include <vm/vm_kern.h>
80 #include <machine/atomic.h>
81 #include <machine/bus.h>
82 #include <machine/cpufunc.h>
83 #include <machine/md_var.h>
86 #define MAX_DMA_SEGMENTS 4096
87 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3
88 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
98 bus_dma_filter_t *filter;
106 bus_dma_lock_t *lockfunc;
108 struct bounce_zone *bounce_zone;
110 * DMA range for this tag. If the page doesn't fall within
111 * one of these ranges, an error is returned. The caller
112 * may then decide what to do with the transfer. If the
113 * range pointer is NULL, it is ignored.
115 struct arm32_dma_range *ranges;
120 vm_offset_t vaddr; /* kva of bounce buffer */
121 bus_addr_t busaddr; /* Physical address */
122 vm_offset_t datavaddr; /* kva of client data */
123 vm_page_t datapage; /* physical page of client data */
124 vm_offset_t dataoffs; /* page offset of client data */
125 bus_size_t datacount; /* client data count */
126 STAILQ_ENTRY(bounce_page) links;
130 vm_offset_t vaddr; /* kva of client data */
131 vm_page_t pages; /* starting page of client data */
132 vm_offset_t dataoffs; /* page offset of client data */
133 bus_size_t datacount; /* client data count */
136 int busdma_swi_pending;
139 STAILQ_ENTRY(bounce_zone) links;
140 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
148 bus_size_t alignment;
152 struct sysctl_ctx_list sysctl_tree;
153 struct sysctl_oid *sysctl_tree_top;
156 static struct mtx bounce_lock;
157 static int total_bpages;
158 static int busdma_zonecount;
159 static uint32_t tags_total;
160 static uint32_t maps_total;
161 static uint32_t maps_dmamem;
162 static uint32_t maps_coherent;
163 static counter_u64_t maploads_total;
164 static counter_u64_t maploads_bounced;
165 static counter_u64_t maploads_coherent;
166 static counter_u64_t maploads_dmamem;
167 static counter_u64_t maploads_mbuf;
168 static counter_u64_t maploads_physmem;
170 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
172 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
173 SYSCTL_UINT(_hw_busdma, OID_AUTO, tags_total, CTLFLAG_RD, &tags_total, 0,
174 "Number of active tags");
175 SYSCTL_UINT(_hw_busdma, OID_AUTO, maps_total, CTLFLAG_RD, &maps_total, 0,
176 "Number of active maps");
177 SYSCTL_UINT(_hw_busdma, OID_AUTO, maps_dmamem, CTLFLAG_RD, &maps_dmamem, 0,
178 "Number of active maps for bus_dmamem_alloc buffers");
179 SYSCTL_UINT(_hw_busdma, OID_AUTO, maps_coherent, CTLFLAG_RD, &maps_coherent, 0,
180 "Number of active maps with BUS_DMA_COHERENT flag set");
181 SYSCTL_COUNTER_U64(_hw_busdma, OID_AUTO, maploads_total, CTLFLAG_RD,
182 &maploads_total, "Number of load operations performed");
183 SYSCTL_COUNTER_U64(_hw_busdma, OID_AUTO, maploads_bounced, CTLFLAG_RD,
184 &maploads_bounced, "Number of load operations that used bounce buffers");
185 SYSCTL_COUNTER_U64(_hw_busdma, OID_AUTO, maploads_coherent, CTLFLAG_RD,
186 &maploads_dmamem, "Number of load operations on BUS_DMA_COHERENT memory");
187 SYSCTL_COUNTER_U64(_hw_busdma, OID_AUTO, maploads_dmamem, CTLFLAG_RD,
188 &maploads_dmamem, "Number of load operations on bus_dmamem_alloc buffers");
189 SYSCTL_COUNTER_U64(_hw_busdma, OID_AUTO, maploads_mbuf, CTLFLAG_RD,
190 &maploads_mbuf, "Number of load operations for mbufs");
191 SYSCTL_COUNTER_U64(_hw_busdma, OID_AUTO, maploads_physmem, CTLFLAG_RD,
192 &maploads_physmem, "Number of load operations on physical buffers");
193 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
194 "Total bounce pages");
197 struct bp_list bpages;
202 bus_dmamap_callback_t *callback;
205 #define DMAMAP_COHERENT (1 << 0)
206 #define DMAMAP_DMAMEM_ALLOC (1 << 1)
207 #define DMAMAP_MBUF (1 << 2)
208 #define DMAMAP_CACHE_ALIGNED (1 << 3)
209 STAILQ_ENTRY(bus_dmamap) links;
210 bus_dma_segment_t *segments;
212 struct sync_list slist[];
215 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
216 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
218 static void init_bounce_pages(void *dummy);
219 static int alloc_bounce_zone(bus_dma_tag_t dmat);
220 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
221 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
223 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
224 vm_offset_t vaddr, bus_addr_t addr, bus_size_t size);
225 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
226 static void bus_dmamap_sync_sl(struct sync_list *sl, bus_dmasync_op_t op,
230 * ----------------------------------------------------------------------------
231 * Begin block of code useful to transplant to other implementations.
234 static busdma_bufalloc_t coherent_allocator; /* Cache of coherent buffers */
235 static busdma_bufalloc_t standard_allocator; /* Cache of standard buffers */
237 MALLOC_DEFINE(M_BUSDMA, "busdma", "busdma metadata");
238 MALLOC_DEFINE(M_BOUNCE, "bounce", "busdma bounce pages");
241 busdma_init(void *dummy)
244 maploads_total = counter_u64_alloc(M_WAITOK);
245 maploads_bounced = counter_u64_alloc(M_WAITOK);
246 maploads_coherent = counter_u64_alloc(M_WAITOK);
247 maploads_dmamem = counter_u64_alloc(M_WAITOK);
248 maploads_mbuf = counter_u64_alloc(M_WAITOK);
249 maploads_physmem = counter_u64_alloc(M_WAITOK);
251 /* Create a cache of buffers in standard (cacheable) memory. */
252 standard_allocator = busdma_bufalloc_create("buffer",
253 arm_dcache_align, /* minimum_alignment */
254 NULL, /* uma_alloc func */
255 NULL, /* uma_free func */
256 0); /* uma_zcreate_flags */
259 * Create a cache of buffers in uncacheable memory, to implement the
260 * BUS_DMA_COHERENT (and potentially BUS_DMA_NOCACHE) flag.
262 coherent_allocator = busdma_bufalloc_create("coherent",
263 arm_dcache_align, /* minimum_alignment */
264 busdma_bufalloc_alloc_uncacheable,
265 busdma_bufalloc_free_uncacheable,
266 0); /* uma_zcreate_flags */
270 * This init historically used SI_SUB_VM, but now the init code requires
271 * malloc(9) using M_BUSDMA memory and the pcpu zones for counter(9), which get
272 * set up by SI_SUB_KMEM and SI_ORDER_LAST, so we'll go right after that by
273 * using SI_SUB_KMEM+1.
275 SYSINIT(busdma, SI_SUB_KMEM+1, SI_ORDER_FIRST, busdma_init, NULL);
278 * End block of code useful to transplant to other implementations.
279 * ----------------------------------------------------------------------------
283 * Return true if a match is made.
285 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
287 * If paddr is within the bounds of the dma tag then call the filter callback
288 * to check for a match, if there is no filter callback then assume a match.
291 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
298 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
299 || ((paddr & (dmat->alignment - 1)) != 0))
300 && (dmat->filter == NULL
301 || (*dmat->filter)(dmat->filterarg, paddr) != 0))
305 } while (retval == 0 && dmat != NULL);
310 * This routine checks the exclusion zone constraints from a tag against the
311 * physical RAM available on the machine. If a tag specifies an exclusion zone
312 * but there's no RAM in that zone, then we avoid allocating resources to bounce
313 * a request, and we can use any memory allocator (as opposed to needing
314 * kmem_alloc_contig() just because it can allocate pages in an address range).
316 * Most tags have BUS_SPACE_MAXADDR or BUS_SPACE_MAXADDR_32BIT (they are the
317 * same value on 32-bit architectures) as their lowaddr constraint, and we can't
318 * possibly have RAM at an address higher than the highest address we can
319 * express, so we take a fast out.
322 _bus_dma_can_bounce(vm_offset_t lowaddr, vm_offset_t highaddr)
326 if (lowaddr >= BUS_SPACE_MAXADDR)
329 for (i = 0; phys_avail[i] && phys_avail[i + 1]; i += 2) {
330 if ((lowaddr >= phys_avail[i] && lowaddr <= phys_avail[i + 1])
331 || (lowaddr < phys_avail[i] &&
332 highaddr > phys_avail[i]))
338 static __inline struct arm32_dma_range *
339 _bus_dma_inrange(struct arm32_dma_range *ranges, int nranges,
342 struct arm32_dma_range *dr;
345 for (i = 0, dr = ranges; i < nranges; i++, dr++) {
346 if (curaddr >= dr->dr_sysbase &&
347 round_page(curaddr) <= (dr->dr_sysbase + dr->dr_len))
355 * Convenience function for manipulating driver locks from busdma (during
356 * busdma_swi, for example). Drivers that don't provide their own locks
357 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own
358 * non-mutex locking scheme don't have to use this at all.
361 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
365 dmtx = (struct mtx *)arg;
374 panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
379 * dflt_lock should never get called. It gets put into the dma tag when
380 * lockfunc == NULL, which is only valid if the maps that are associated
381 * with the tag are meant to never be defered.
382 * XXX Should have a way to identify which driver is responsible here.
385 dflt_lock(void *arg, bus_dma_lock_op_t op)
388 panic("driver error: busdma dflt_lock called");
390 printf("DRIVER_ERROR: busdma dflt_lock called\n");
395 * Allocate a device specific dma_tag.
398 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
399 bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
400 bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
401 int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
402 void *lockfuncarg, bus_dma_tag_t *dmat)
404 bus_dma_tag_t newtag;
406 /* Return a NULL tag on failure */
409 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_BUSDMA, M_NOWAIT);
410 if (newtag == NULL) {
411 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
412 __func__, newtag, 0, error);
416 newtag->parent = parent;
417 newtag->alignment = alignment ? alignment : 1;
418 newtag->boundary = boundary;
419 newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
420 newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
421 newtag->filter = filter;
422 newtag->filterarg = filterarg;
423 newtag->maxsize = maxsize;
424 newtag->nsegments = nsegments;
425 newtag->maxsegsz = maxsegsz;
426 newtag->flags = flags;
427 newtag->ref_count = 1; /* Count ourself */
428 newtag->map_count = 0;
429 newtag->ranges = bus_dma_get_range();
430 newtag->_nranges = bus_dma_get_range_nb();
431 if (lockfunc != NULL) {
432 newtag->lockfunc = lockfunc;
433 newtag->lockfuncarg = lockfuncarg;
435 newtag->lockfunc = dflt_lock;
436 newtag->lockfuncarg = NULL;
439 /* Take into account any restrictions imposed by our parent tag */
440 if (parent != NULL) {
441 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
442 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
443 if (newtag->boundary == 0)
444 newtag->boundary = parent->boundary;
445 else if (parent->boundary != 0)
446 newtag->boundary = MIN(parent->boundary,
448 if ((newtag->filter != NULL) ||
449 ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
450 newtag->flags |= BUS_DMA_COULD_BOUNCE;
451 if (newtag->filter == NULL) {
453 * Short circuit looking at our parent directly
454 * since we have encapsulated all of its information
456 newtag->filter = parent->filter;
457 newtag->filterarg = parent->filterarg;
458 newtag->parent = parent->parent;
460 if (newtag->parent != NULL)
461 atomic_add_int(&parent->ref_count, 1);
463 if (_bus_dma_can_bounce(newtag->lowaddr, newtag->highaddr)
464 || newtag->alignment > 1)
465 newtag->flags |= BUS_DMA_COULD_BOUNCE;
467 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
468 (flags & BUS_DMA_ALLOCNOW) != 0) {
469 struct bounce_zone *bz;
473 if ((error = alloc_bounce_zone(newtag)) != 0) {
474 free(newtag, M_BUSDMA);
477 bz = newtag->bounce_zone;
479 if (ptoa(bz->total_bpages) < maxsize) {
482 pages = atop(maxsize) - bz->total_bpages;
484 /* Add pages to our bounce pool */
485 if (alloc_bounce_pages(newtag, pages) < pages)
488 /* Performed initial allocation */
489 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
491 newtag->bounce_zone = NULL;
494 free(newtag, M_BUSDMA);
496 atomic_add_32(&tags_total, 1);
499 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
500 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
505 bus_dma_template_init(bus_dma_tag_template_t *t, bus_dma_tag_t parent)
514 t->lowaddr = t->highaddr = BUS_SPACE_MAXADDR;
515 t->maxsize = t->maxsegsize = BUS_SPACE_MAXSIZE;
516 t->nsegments = BUS_SPACE_UNRESTRICTED;
518 t->lockfuncarg = NULL;
523 bus_dma_template_tag(bus_dma_tag_template_t *t, bus_dma_tag_t *dmat)
526 if (t == NULL || dmat == NULL)
529 return (bus_dma_tag_create(t->parent, t->alignment, t->boundary,
530 t->lowaddr, t->highaddr, NULL, NULL, t->maxsize,
531 t->nsegments, t->maxsegsize, t->flags, t->lockfunc, t->lockfuncarg,
536 bus_dma_template_clone(bus_dma_tag_template_t *t, bus_dma_tag_t dmat)
539 if (t == NULL || dmat == NULL)
542 t->parent = dmat->parent;
543 t->alignment = dmat->alignment;
544 t->boundary = dmat->boundary;
545 t->lowaddr = dmat->lowaddr;
546 t->highaddr = dmat->highaddr;
547 t->maxsize = dmat->maxsize;
548 t->nsegments = dmat->nsegments;
549 t->maxsegsize = dmat->maxsegsz;
550 t->flags = dmat->flags;
551 t->lockfunc = dmat->lockfunc;
552 t->lockfuncarg = dmat->lockfuncarg;
556 bus_dma_tag_set_domain(bus_dma_tag_t dmat, int domain)
563 bus_dma_tag_destroy(bus_dma_tag_t dmat)
565 bus_dma_tag_t dmat_copy;
573 if (dmat->map_count != 0) {
578 while (dmat != NULL) {
579 bus_dma_tag_t parent;
581 parent = dmat->parent;
582 atomic_subtract_int(&dmat->ref_count, 1);
583 if (dmat->ref_count == 0) {
584 atomic_subtract_32(&tags_total, 1);
585 free(dmat, M_BUSDMA);
587 * Last reference count, so
588 * release our reference
589 * count on our parent.
597 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
602 allocate_bz_and_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
607 * Bouncing might be required if the driver asks for an active
608 * exclusion region, a data alignment that is stricter than 1, and/or
609 * an active address boundary.
611 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
614 struct bounce_zone *bz;
617 if (dmat->bounce_zone == NULL) {
618 if ((error = alloc_bounce_zone(dmat)) != 0) {
622 bz = dmat->bounce_zone;
624 /* Initialize the new map */
625 STAILQ_INIT(&(map->bpages));
628 * Attempt to add pages to our pool on a per-instance
629 * basis up to a sane limit.
631 maxpages = MAX_BPAGES;
632 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
633 || (bz->map_count > 0 && bz->total_bpages < maxpages)) {
636 pages = MAX(atop(dmat->maxsize), 1);
637 pages = MIN(maxpages - bz->total_bpages, pages);
638 pages = MAX(pages, 1);
639 if (alloc_bounce_pages(dmat, pages) < pages)
642 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0)
643 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
651 allocate_map(bus_dma_tag_t dmat, int mflags)
653 int mapsize, segsize;
657 * Allocate the map. The map structure ends with an embedded
658 * variable-sized array of sync_list structures. Following that
659 * we allocate enough extra space to hold the array of bus_dma_segments.
661 KASSERT(dmat->nsegments <= MAX_DMA_SEGMENTS,
662 ("cannot allocate %u dma segments (max is %u)",
663 dmat->nsegments, MAX_DMA_SEGMENTS));
664 segsize = sizeof(struct bus_dma_segment) * dmat->nsegments;
665 mapsize = sizeof(*map) + sizeof(struct sync_list) * dmat->nsegments;
666 map = malloc(mapsize + segsize, M_BUSDMA, mflags | M_ZERO);
668 CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, ENOMEM);
671 map->segments = (bus_dma_segment_t *)((uintptr_t)map + mapsize);
676 * Allocate a handle for mapping from kva/uva/physical
677 * address space into bus device space.
680 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
685 *mapp = map = allocate_map(dmat, M_NOWAIT);
687 CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, ENOMEM);
692 * Bouncing might be required if the driver asks for an exclusion
693 * region, a data alignment that is stricter than 1, or DMA that begins
694 * or ends with a partial cacheline. Whether bouncing will actually
695 * happen can't be known until mapping time, but we need to pre-allocate
696 * resources now because we might not be allowed to at mapping time.
698 error = allocate_bz_and_pages(dmat, map);
704 if (map->flags & DMAMAP_COHERENT)
705 atomic_add_32(&maps_coherent, 1);
706 atomic_add_32(&maps_total, 1);
713 * Destroy a handle for mapping from kva/uva/physical
714 * address space into bus device space.
717 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
720 if (STAILQ_FIRST(&map->bpages) != NULL || map->sync_count != 0) {
721 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
722 __func__, dmat, EBUSY);
725 if (dmat->bounce_zone)
726 dmat->bounce_zone->map_count--;
727 if (map->flags & DMAMAP_COHERENT)
728 atomic_subtract_32(&maps_coherent, 1);
729 atomic_subtract_32(&maps_total, 1);
732 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
737 * Allocate a piece of memory that can be efficiently mapped into bus device
738 * space based on the constraints listed in the dma tag. Returns a pointer to
739 * the allocated memory, and a pointer to an associated bus_dmamap.
742 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
745 busdma_bufalloc_t ba;
746 struct busdma_bufzone *bufzone;
748 vm_memattr_t memattr;
751 if (flags & BUS_DMA_NOWAIT)
755 if (flags & BUS_DMA_ZERO)
758 *mapp = map = allocate_map(dmat, mflags);
760 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
761 __func__, dmat, dmat->flags, ENOMEM);
764 map->flags = DMAMAP_DMAMEM_ALLOC;
766 /* Choose a busdma buffer allocator based on memory type flags. */
767 if (flags & BUS_DMA_COHERENT) {
768 memattr = VM_MEMATTR_UNCACHEABLE;
769 ba = coherent_allocator;
770 map->flags |= DMAMAP_COHERENT;
772 memattr = VM_MEMATTR_DEFAULT;
773 ba = standard_allocator;
777 * Try to find a bufzone in the allocator that holds a cache of buffers
778 * of the right size for this request. If the buffer is too big to be
779 * held in the allocator cache, this returns NULL.
781 bufzone = busdma_bufalloc_findzone(ba, dmat->maxsize);
784 * Allocate the buffer from the uma(9) allocator if...
785 * - It's small enough to be in the allocator (bufzone not NULL).
786 * - The alignment constraint isn't larger than the allocation size
787 * (the allocator aligns buffers to their size boundaries).
788 * - There's no need to handle lowaddr/highaddr exclusion zones.
789 * else allocate non-contiguous pages if...
790 * - The page count that could get allocated doesn't exceed nsegments.
791 * - The alignment constraint isn't larger than a page boundary.
792 * - There are no boundary-crossing constraints.
793 * else allocate a block of contiguous pages because one or more of the
794 * constraints is something that only the contig allocator can fulfill.
796 if (bufzone != NULL && dmat->alignment <= bufzone->size &&
797 !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr)) {
798 *vaddr = uma_zalloc(bufzone->umazone, mflags);
799 } else if (dmat->nsegments >=
800 howmany(dmat->maxsize, MIN(dmat->maxsegsz, PAGE_SIZE)) &&
801 dmat->alignment <= PAGE_SIZE &&
802 (dmat->boundary % PAGE_SIZE) == 0) {
803 *vaddr = (void *)kmem_alloc_attr(dmat->maxsize, mflags, 0,
804 dmat->lowaddr, memattr);
806 *vaddr = (void *)kmem_alloc_contig(dmat->maxsize, mflags, 0,
807 dmat->lowaddr, dmat->alignment, dmat->boundary, memattr);
809 if (*vaddr == NULL) {
810 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
811 __func__, dmat, dmat->flags, ENOMEM);
816 if (map->flags & DMAMAP_COHERENT)
817 atomic_add_32(&maps_coherent, 1);
818 atomic_add_32(&maps_dmamem, 1);
819 atomic_add_32(&maps_total, 1);
822 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
823 __func__, dmat, dmat->flags, 0);
828 * Free a piece of memory that was allocated via bus_dmamem_alloc, along with
829 * its associated map.
832 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
834 struct busdma_bufzone *bufzone;
835 busdma_bufalloc_t ba;
837 if (map->flags & DMAMAP_COHERENT)
838 ba = coherent_allocator;
840 ba = standard_allocator;
842 bufzone = busdma_bufalloc_findzone(ba, dmat->maxsize);
844 if (bufzone != NULL && dmat->alignment <= bufzone->size &&
845 !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr))
846 uma_zfree(bufzone->umazone, vaddr);
848 kmem_free((vm_offset_t)vaddr, dmat->maxsize);
851 if (map->flags & DMAMAP_COHERENT)
852 atomic_subtract_32(&maps_coherent, 1);
853 atomic_subtract_32(&maps_total, 1);
854 atomic_subtract_32(&maps_dmamem, 1);
856 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
860 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
861 bus_size_t buflen, int flags)
866 if (map->pagesneeded == 0) {
867 CTR3(KTR_BUSDMA, "lowaddr= %d, boundary= %d, alignment= %d",
868 dmat->lowaddr, dmat->boundary, dmat->alignment);
869 CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d",
870 map, map->pagesneeded);
872 * Count the number of bounce pages
873 * needed in order to complete this transfer
876 while (buflen != 0) {
877 sgsize = MIN(buflen, dmat->maxsegsz);
878 if (run_filter(dmat, curaddr) != 0) {
880 PAGE_SIZE - (curaddr & PAGE_MASK));
886 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
891 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
892 void *buf, bus_size_t buflen, int flags)
895 vm_offset_t vendaddr;
898 if (map->pagesneeded == 0) {
899 CTR3(KTR_BUSDMA, "lowaddr= %d, boundary= %d, alignment= %d",
900 dmat->lowaddr, dmat->boundary, dmat->alignment);
901 CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d",
902 map, map->pagesneeded);
904 * Count the number of bounce pages
905 * needed in order to complete this transfer
907 vaddr = trunc_page((vm_offset_t)buf);
908 vendaddr = (vm_offset_t)buf + buflen;
910 while (vaddr < vendaddr) {
911 if (__predict_true(pmap == kernel_pmap))
912 paddr = pmap_kextract(vaddr);
914 paddr = pmap_extract(pmap, vaddr);
915 if (run_filter(dmat, paddr) != 0)
919 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
924 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
927 /* Reserve Necessary Bounce Pages */
928 mtx_lock(&bounce_lock);
929 if (flags & BUS_DMA_NOWAIT) {
930 if (reserve_bounce_pages(dmat, map, 0) != 0) {
931 mtx_unlock(&bounce_lock);
935 if (reserve_bounce_pages(dmat, map, 1) != 0) {
936 /* Queue us for resources */
937 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
938 mtx_unlock(&bounce_lock);
939 return (EINPROGRESS);
942 mtx_unlock(&bounce_lock);
948 * Add a single contiguous physical range to the segment list.
951 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
952 bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
954 bus_addr_t baddr, bmask;
958 * Make sure we don't cross any boundaries.
960 bmask = ~(dmat->boundary - 1);
961 if (dmat->boundary > 0) {
962 baddr = (curaddr + dmat->boundary) & bmask;
963 if (sgsize > (baddr - curaddr))
964 sgsize = (baddr - curaddr);
967 struct arm32_dma_range *dr;
969 dr = _bus_dma_inrange(dmat->ranges, dmat->_nranges,
974 * In a valid DMA range. Translate the physical
975 * memory address to an address in the DMA window.
977 curaddr = (curaddr - dr->dr_sysbase) + dr->dr_busbase;
983 * Insert chunk into a segment, coalescing with
984 * the previous segment if possible.
987 curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
988 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
989 (dmat->boundary == 0 ||
990 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) {
991 segs[seg].ds_len += sgsize;
993 if (++seg >= dmat->nsegments)
995 segs[seg].ds_addr = curaddr;
996 segs[seg].ds_len = sgsize;
1003 * Utility function to load a physical buffer. segp contains
1004 * the starting segment on entrace, and the ending segment on exit.
1007 _bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
1008 bus_size_t buflen, int flags, bus_dma_segment_t *segs, int *segp)
1011 bus_addr_t sl_end = 0;
1013 struct sync_list *sl;
1017 segs = map->segments;
1019 counter_u64_add(maploads_total, 1);
1020 counter_u64_add(maploads_physmem, 1);
1022 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
1023 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
1024 if (map->pagesneeded != 0) {
1025 counter_u64_add(maploads_bounced, 1);
1026 error = _bus_dmamap_reserve_pages(dmat, map, flags);
1032 sl = map->slist + map->sync_count - 1;
1034 while (buflen > 0) {
1036 sgsize = MIN(buflen, dmat->maxsegsz);
1037 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
1038 map->pagesneeded != 0 && run_filter(dmat, curaddr)) {
1039 sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
1040 curaddr = add_bounce_page(dmat, map, 0, curaddr,
1043 if (map->sync_count > 0)
1044 sl_end = VM_PAGE_TO_PHYS(sl->pages) +
1045 sl->dataoffs + sl->datacount;
1047 if (map->sync_count == 0 || curaddr != sl_end) {
1048 if (++map->sync_count > dmat->nsegments)
1052 sl->datacount = sgsize;
1053 sl->pages = PHYS_TO_VM_PAGE(curaddr);
1054 sl->dataoffs = curaddr & PAGE_MASK;
1056 sl->datacount += sgsize;
1058 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
1070 bus_dmamap_unload(dmat, map);
1071 return (EFBIG); /* XXX better return value here? */
1077 _bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
1078 struct vm_page **ma, bus_size_t tlen, int ma_offs, int flags,
1079 bus_dma_segment_t *segs, int *segp)
1082 return (bus_dmamap_load_ma_triv(dmat, map, ma, tlen, ma_offs, flags,
1087 * Utility function to load a linear buffer. segp contains
1088 * the starting segment on entrance, and the ending segment on exit.
1091 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
1092 bus_size_t buflen, struct pmap *pmap, int flags, bus_dma_segment_t *segs,
1097 bus_addr_t sl_pend = 0;
1098 struct sync_list *sl;
1100 vm_offset_t vaddr = (vm_offset_t)buf;
1101 vm_offset_t sl_vend = 0;
1104 counter_u64_add(maploads_total, 1);
1105 if (map->flags & DMAMAP_COHERENT)
1106 counter_u64_add(maploads_coherent, 1);
1107 if (map->flags & DMAMAP_DMAMEM_ALLOC)
1108 counter_u64_add(maploads_dmamem, 1);
1111 segs = map->segments;
1112 if (flags & BUS_DMA_LOAD_MBUF) {
1113 counter_u64_add(maploads_mbuf, 1);
1114 map->flags |= DMAMAP_CACHE_ALIGNED;
1117 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
1118 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
1119 if (map->pagesneeded != 0) {
1120 counter_u64_add(maploads_bounced, 1);
1121 error = _bus_dmamap_reserve_pages(dmat, map, flags);
1126 CTR3(KTR_BUSDMA, "lowaddr= %d boundary= %d, "
1127 "alignment= %d", dmat->lowaddr, dmat->boundary, dmat->alignment);
1129 sl = map->slist + map->sync_count - 1;
1131 while (buflen > 0) {
1133 * Get the physical address for this segment.
1135 if (__predict_true(pmap == kernel_pmap)) {
1136 curaddr = pmap_kextract(vaddr);
1139 curaddr = pmap_extract(pmap, vaddr);
1140 map->flags &= ~DMAMAP_COHERENT;
1145 * Compute the segment size, and adjust counts.
1147 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
1148 if (sgsize > dmat->maxsegsz)
1149 sgsize = dmat->maxsegsz;
1150 if (buflen < sgsize)
1153 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
1154 map->pagesneeded != 0 && run_filter(dmat, curaddr)) {
1155 curaddr = add_bounce_page(dmat, map, kvaddr, curaddr,
1158 if (map->sync_count > 0) {
1159 sl_pend = VM_PAGE_TO_PHYS(sl->pages) +
1160 sl->dataoffs + sl->datacount;
1161 sl_vend = sl->vaddr + sl->datacount;
1164 if (map->sync_count == 0 ||
1165 (kvaddr != 0 && kvaddr != sl_vend) ||
1166 (kvaddr == 0 && curaddr != sl_pend)) {
1168 if (++map->sync_count > dmat->nsegments)
1172 sl->datacount = sgsize;
1173 sl->pages = PHYS_TO_VM_PAGE(curaddr);
1174 sl->dataoffs = curaddr & PAGE_MASK;
1176 sl->datacount += sgsize;
1178 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
1191 bus_dmamap_unload(dmat, map);
1192 return (EFBIG); /* XXX better return value here? */
1198 _bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map, struct memdesc *mem,
1199 bus_dmamap_callback_t *callback, void *callback_arg)
1202 KASSERT(dmat != NULL, ("dmatag is NULL"));
1203 KASSERT(map != NULL, ("dmamap is NULL"));
1205 map->callback = callback;
1206 map->callback_arg = callback_arg;
1210 _bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
1211 bus_dma_segment_t *segs, int nsegs, int error)
1215 segs = map->segments;
1220 * Release the mapping held by map.
1223 bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1225 struct bounce_page *bpage;
1226 struct bounce_zone *bz;
1228 if ((bz = dmat->bounce_zone) != NULL) {
1229 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1230 STAILQ_REMOVE_HEAD(&map->bpages, links);
1231 free_bounce_page(dmat, bpage);
1234 bz = dmat->bounce_zone;
1235 bz->free_bpages += map->pagesreserved;
1236 bz->reserved_bpages -= map->pagesreserved;
1237 map->pagesreserved = 0;
1238 map->pagesneeded = 0;
1240 map->sync_count = 0;
1241 map->flags &= ~DMAMAP_MBUF;
1245 bus_dmamap_sync_buf(vm_offset_t buf, int len, bus_dmasync_op_t op,
1248 char _tmp_cl[arm_dcache_align], _tmp_clend[arm_dcache_align];
1252 if ((op & BUS_DMASYNC_PREWRITE) && !(op & BUS_DMASYNC_PREREAD)) {
1253 cpu_dcache_wb_range(buf, len);
1254 cpu_l2cache_wb_range(buf, len);
1258 * If the caller promises the buffer is properly aligned to a cache line
1259 * (even if the call parms make it look like it isn't) we can avoid
1260 * attempting to preserve the non-DMA part of the cache line in the
1261 * POSTREAD case, but we MUST still do a writeback in the PREREAD case.
1263 * This covers the case of mbufs, where we know how they're aligned and
1264 * know the CPU doesn't touch the header in front of the DMA data area
1265 * during the IO, but it may have touched it right before invoking the
1266 * sync, so a PREREAD writeback is required.
1268 * It also handles buffers we created in bus_dmamem_alloc(), which are
1269 * always aligned and padded to cache line size even if the IO length
1270 * isn't a multiple of cache line size. In this case the PREREAD
1271 * writeback probably isn't required, but it's harmless.
1273 partial = (((vm_offset_t)buf) | len) & arm_dcache_align_mask;
1275 if (op & BUS_DMASYNC_PREREAD) {
1276 if (!(op & BUS_DMASYNC_PREWRITE) && !partial) {
1277 cpu_dcache_inv_range(buf, len);
1278 cpu_l2cache_inv_range(buf, len);
1280 cpu_dcache_wbinv_range(buf, len);
1281 cpu_l2cache_wbinv_range(buf, len);
1284 if (op & BUS_DMASYNC_POSTREAD) {
1285 if (partial && !bufaligned) {
1287 if (buf & arm_dcache_align_mask)
1288 memcpy(_tmp_cl, (void *)(buf &
1289 ~arm_dcache_align_mask),
1290 buf & arm_dcache_align_mask);
1291 if ((buf + len) & arm_dcache_align_mask)
1293 (void *)(buf + len),
1295 ((buf + len) & arm_dcache_align_mask));
1297 cpu_dcache_inv_range(buf, len);
1298 cpu_l2cache_inv_range(buf, len);
1299 if (partial && !bufaligned) {
1300 if (buf & arm_dcache_align_mask)
1301 memcpy((void *)(buf &
1302 ~arm_dcache_align_mask), _tmp_cl,
1303 buf & arm_dcache_align_mask);
1304 if ((buf + len) & arm_dcache_align_mask)
1305 memcpy((void *)(buf + len),
1306 _tmp_clend, arm_dcache_align -
1307 ((buf + len) & arm_dcache_align_mask));
1314 bus_dmamap_sync_sl(struct sync_list *sl, bus_dmasync_op_t op,
1317 vm_offset_t tempvaddr;
1321 if (sl->vaddr != 0) {
1322 bus_dmamap_sync_buf(sl->vaddr, sl->datacount, op, bufaligned);
1327 npages = atop(round_page(sl->dataoffs + sl->datacount));
1329 for (curpage = sl->pages; curpage != sl->pages + npages; ++curpage) {
1331 * If the page is mapped to some other VA that hasn't
1332 * been supplied to busdma, then pmap_quick_enter_page()
1333 * will find all duplicate mappings and mark them
1335 * That will also do any necessary wb/inv. Otherwise,
1336 * if the page is truly unmapped, then we don't actually
1337 * need to do cache maintenance.
1338 * XXX: May overwrite DMA'ed data in the POSTREAD
1339 * case where the CPU has written to a cacheline not
1340 * completely covered by the DMA region.
1342 KASSERT(VM_PAGE_TO_PHYS(curpage) == VM_PAGE_TO_PHYS(sl->pages) +
1343 ptoa(curpage - sl->pages),
1344 ("unexpected vm_page_t phys: 0x%08x != 0x%08x",
1345 VM_PAGE_TO_PHYS(curpage), VM_PAGE_TO_PHYS(sl->pages) +
1346 ptoa(curpage - sl->pages)));
1347 tempvaddr = pmap_quick_enter_page(curpage);
1348 pmap_quick_remove_page(tempvaddr);
1353 _bus_dmamap_sync_bp(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1355 struct bounce_page *bpage;
1356 vm_offset_t datavaddr, tempvaddr;
1358 if ((op & (BUS_DMASYNC_PREWRITE | BUS_DMASYNC_POSTREAD)) == 0)
1361 STAILQ_FOREACH(bpage, &map->bpages, links) {
1363 datavaddr = bpage->datavaddr;
1364 if (op & BUS_DMASYNC_PREWRITE) {
1365 if (datavaddr == 0) {
1367 pmap_quick_enter_page(bpage->datapage);
1368 datavaddr = tempvaddr | bpage->dataoffs;
1370 bcopy((void *)datavaddr,
1371 (void *)bpage->vaddr, bpage->datacount);
1373 pmap_quick_remove_page(tempvaddr);
1374 cpu_dcache_wb_range(bpage->vaddr, bpage->datacount);
1375 cpu_l2cache_wb_range(bpage->vaddr, bpage->datacount);
1376 dmat->bounce_zone->total_bounced++;
1378 if (op & BUS_DMASYNC_POSTREAD) {
1379 cpu_dcache_inv_range(bpage->vaddr, bpage->datacount);
1380 cpu_l2cache_inv_range(bpage->vaddr, bpage->datacount);
1381 if (datavaddr == 0) {
1383 pmap_quick_enter_page(bpage->datapage);
1384 datavaddr = tempvaddr | bpage->dataoffs;
1386 bcopy((void *)bpage->vaddr,
1387 (void *)datavaddr, bpage->datacount);
1389 pmap_quick_remove_page(tempvaddr);
1390 dmat->bounce_zone->total_bounced++;
1396 bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1398 struct sync_list *sl, *end;
1401 if (op == BUS_DMASYNC_POSTWRITE)
1403 if (map->flags & DMAMAP_COHERENT)
1405 if (STAILQ_FIRST(&map->bpages))
1406 _bus_dmamap_sync_bp(dmat, map, op);
1407 CTR3(KTR_BUSDMA, "%s: op %x flags %x", __func__, op, map->flags);
1408 bufaligned = (map->flags & DMAMAP_CACHE_ALIGNED);
1409 if (map->sync_count) {
1410 end = &map->slist[map->sync_count];
1411 for (sl = &map->slist[0]; sl != end; sl++)
1412 bus_dmamap_sync_sl(sl, op, bufaligned);
1417 cpu_drain_writebuf();
1421 init_bounce_pages(void *dummy __unused)
1425 STAILQ_INIT(&bounce_zone_list);
1426 STAILQ_INIT(&bounce_map_waitinglist);
1427 STAILQ_INIT(&bounce_map_callbacklist);
1428 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1430 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1432 static struct sysctl_ctx_list *
1433 busdma_sysctl_tree(struct bounce_zone *bz)
1436 return (&bz->sysctl_tree);
1439 static struct sysctl_oid *
1440 busdma_sysctl_tree_top(struct bounce_zone *bz)
1443 return (bz->sysctl_tree_top);
1447 alloc_bounce_zone(bus_dma_tag_t dmat)
1449 struct bounce_zone *bz;
1451 /* Check to see if we already have a suitable zone */
1452 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1453 if ((dmat->alignment <= bz->alignment) &&
1454 (dmat->lowaddr >= bz->lowaddr)) {
1455 dmat->bounce_zone = bz;
1460 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_BUSDMA,
1461 M_NOWAIT | M_ZERO)) == NULL)
1464 STAILQ_INIT(&bz->bounce_page_list);
1465 bz->free_bpages = 0;
1466 bz->reserved_bpages = 0;
1467 bz->active_bpages = 0;
1468 bz->lowaddr = dmat->lowaddr;
1469 bz->alignment = MAX(dmat->alignment, PAGE_SIZE);
1471 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1473 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1474 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1475 dmat->bounce_zone = bz;
1477 sysctl_ctx_init(&bz->sysctl_tree);
1478 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1479 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1481 if (bz->sysctl_tree_top == NULL) {
1482 sysctl_ctx_free(&bz->sysctl_tree);
1483 return (0); /* XXX error code? */
1486 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1487 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1488 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1489 "Total bounce pages");
1490 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1491 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1492 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1493 "Free bounce pages");
1494 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1495 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1496 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1497 "Reserved bounce pages");
1498 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1499 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1500 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1501 "Active bounce pages");
1502 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1503 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1504 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1505 "Total bounce requests (pages bounced)");
1506 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1507 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1508 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1509 "Total bounce requests that were deferred");
1510 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1511 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1512 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1513 SYSCTL_ADD_ULONG(busdma_sysctl_tree(bz),
1514 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1515 "alignment", CTLFLAG_RD, &bz->alignment, "");
1521 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1523 struct bounce_zone *bz;
1526 bz = dmat->bounce_zone;
1528 while (numpages > 0) {
1529 struct bounce_page *bpage;
1531 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_BUSDMA,
1536 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_BOUNCE,
1537 M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
1538 if (bpage->vaddr == 0) {
1539 free(bpage, M_BUSDMA);
1542 bpage->busaddr = pmap_kextract(bpage->vaddr);
1543 mtx_lock(&bounce_lock);
1544 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1548 mtx_unlock(&bounce_lock);
1556 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1558 struct bounce_zone *bz;
1561 mtx_assert(&bounce_lock, MA_OWNED);
1562 bz = dmat->bounce_zone;
1563 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1564 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1565 return (map->pagesneeded - (map->pagesreserved + pages));
1566 bz->free_bpages -= pages;
1567 bz->reserved_bpages += pages;
1568 map->pagesreserved += pages;
1569 pages = map->pagesneeded - map->pagesreserved;
1575 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1576 bus_addr_t addr, bus_size_t size)
1578 struct bounce_zone *bz;
1579 struct bounce_page *bpage;
1581 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1582 KASSERT(map != NULL, ("add_bounce_page: bad map %p", map));
1584 bz = dmat->bounce_zone;
1585 if (map->pagesneeded == 0)
1586 panic("add_bounce_page: map doesn't need any pages");
1589 if (map->pagesreserved == 0)
1590 panic("add_bounce_page: map doesn't need any pages");
1591 map->pagesreserved--;
1593 mtx_lock(&bounce_lock);
1594 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1596 panic("add_bounce_page: free page list is empty");
1598 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1599 bz->reserved_bpages--;
1600 bz->active_bpages++;
1601 mtx_unlock(&bounce_lock);
1603 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1604 /* Page offset needs to be preserved. */
1605 bpage->vaddr |= addr & PAGE_MASK;
1606 bpage->busaddr |= addr & PAGE_MASK;
1608 bpage->datavaddr = vaddr;
1609 bpage->datapage = PHYS_TO_VM_PAGE(addr);
1610 bpage->dataoffs = addr & PAGE_MASK;
1611 bpage->datacount = size;
1612 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1613 return (bpage->busaddr);
1617 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1619 struct bus_dmamap *map;
1620 struct bounce_zone *bz;
1622 bz = dmat->bounce_zone;
1623 bpage->datavaddr = 0;
1624 bpage->datacount = 0;
1625 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1627 * Reset the bounce page to start at offset 0. Other uses
1628 * of this bounce page may need to store a full page of
1629 * data and/or assume it starts on a page boundary.
1631 bpage->vaddr &= ~PAGE_MASK;
1632 bpage->busaddr &= ~PAGE_MASK;
1635 mtx_lock(&bounce_lock);
1636 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1638 bz->active_bpages--;
1639 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1640 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1641 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1642 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1644 busdma_swi_pending = 1;
1645 bz->total_deferred++;
1646 swi_sched(vm_ih, 0);
1649 mtx_unlock(&bounce_lock);
1656 struct bus_dmamap *map;
1658 mtx_lock(&bounce_lock);
1659 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1660 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1661 mtx_unlock(&bounce_lock);
1663 dmat->lockfunc(dmat->lockfuncarg, BUS_DMA_LOCK);
1664 bus_dmamap_load_mem(map->dmat, map, &map->mem, map->callback,
1665 map->callback_arg, BUS_DMA_WAITOK);
1666 dmat->lockfunc(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1667 mtx_lock(&bounce_lock);
1669 mtx_unlock(&bounce_lock);