2 * Copyright (c) 1997, 1998 Justin T. Gibbs.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions, and the following disclaimer,
10 * without modification, immediately at the beginning of the file.
11 * 2. The name of the author may not be used to endorse or promote products
12 * derived from this software without specific prior written permission.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
18 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/i386/i386/busdma_machdep.c,v 1.16.2.2 2003/01/23 00:55:27 scottl Exp $
27 * $DragonFly: src/sys/platform/pc32/i386/busdma_machdep.c,v 1.23 2008/06/05 18:06:32 swildner Exp $
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
35 #include <sys/thread2.h>
36 #include <sys/bus_dma.h>
37 #include <sys/kernel.h>
38 #include <sys/sysctl.h>
41 #include <vm/vm_page.h>
43 /* XXX needed for to access pmap to convert per-proc virtual to physical */
46 #include <vm/vm_map.h>
48 #include <machine/md_var.h>
50 #define MAX_BPAGES 1024
58 bus_dma_filter_t *filter;
66 bus_dma_segment_t *segments;
70 * bus_dma_tag private flags
72 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
75 vm_offset_t vaddr; /* kva of bounce buffer */
76 bus_addr_t busaddr; /* Physical address */
77 vm_offset_t datavaddr; /* kva of client data */
78 bus_size_t datacount; /* client data count */
79 STAILQ_ENTRY(bounce_page) links;
82 int busdma_swi_pending;
84 static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
85 static int free_bpages;
86 static int reserved_bpages;
87 static int active_bpages;
88 static int total_bpages;
89 static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
92 struct bp_list bpages;
96 void *buf; /* unmapped buffer pointer */
97 bus_size_t buflen; /* unmapped buffer length */
98 bus_dmamap_callback_t *callback;
100 STAILQ_ENTRY(bus_dmamap) links;
103 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
104 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
105 static struct bus_dmamap nobounce_dmamap;
107 static int alloc_bounce_pages(bus_dma_tag_t, u_int);
108 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
109 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
110 vm_offset_t, bus_size_t);
111 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *);
113 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
114 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
115 "Total bounce pages");
118 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
124 if (paddr > dmat->lowaddr
125 && paddr <= dmat->highaddr
126 && (dmat->filter == NULL
127 || (*dmat->filter)(dmat->filterarg, paddr) != 0))
131 } while (retval == 0 && dmat != NULL);
136 * Allocate a device specific dma_tag.
139 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
140 bus_size_t boundary, bus_addr_t lowaddr,
141 bus_addr_t highaddr, bus_dma_filter_t *filter,
142 void *filterarg, bus_size_t maxsize, int nsegments,
143 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
145 bus_dma_tag_t newtag;
148 /* Return a NULL tag on failure */
151 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
153 newtag->parent = parent;
154 newtag->alignment = alignment;
155 newtag->boundary = boundary;
156 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
157 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
158 newtag->filter = filter;
159 newtag->filterarg = filterarg;
160 newtag->maxsize = maxsize;
161 newtag->nsegments = nsegments;
162 newtag->maxsegsz = maxsegsz;
163 newtag->flags = flags;
164 newtag->ref_count = 1; /* Count ourself */
165 newtag->map_count = 0;
166 newtag->segments = NULL;
168 /* Take into account any restrictions imposed by our parent tag */
169 if (parent != NULL) {
170 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
171 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
173 * XXX Not really correct??? Probably need to honor boundary
174 * all the way up the inheritence chain.
176 newtag->boundary = MAX(parent->boundary, newtag->boundary);
177 if (newtag->filter == NULL) {
179 * Short circuit looking at our parent directly
180 * since we have encapsulated all of its information
182 newtag->filter = parent->filter;
183 newtag->filterarg = parent->filterarg;
184 newtag->parent = parent->parent;
186 if (newtag->parent != NULL)
190 if (newtag->lowaddr < ptoa(Maxmem) &&
191 (flags & BUS_DMA_ALLOCNOW) != 0) {
194 if (lowaddr > bounce_lowaddr) {
196 * Go through the pool and kill any pages
197 * that don't reside below lowaddr.
199 panic("bus_dma_tag_create: page reallocation "
202 if (ptoa(total_bpages) < maxsize) {
205 pages = atop(maxsize) - total_bpages;
207 /* Add pages to our bounce pool */
208 if (alloc_bounce_pages(newtag, pages) < pages)
211 /* Performed initial allocation */
212 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
216 kfree(newtag, M_DEVBUF);
224 bus_dma_tag_destroy(bus_dma_tag_t dmat)
227 if (dmat->map_count != 0)
230 while (dmat != NULL) {
231 bus_dma_tag_t parent;
233 parent = dmat->parent;
235 if (dmat->ref_count == 0) {
236 if (dmat->segments != NULL)
237 kfree(dmat->segments, M_DEVBUF);
238 kfree(dmat, M_DEVBUF);
240 * Last reference count, so
241 * release our reference
242 * count on our parent.
253 * Allocate a handle for mapping from kva/uva/physical
254 * address space into bus device space.
257 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
263 if (dmat->segments == NULL) {
264 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
265 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
266 dmat->nsegments, M_DEVBUF, M_INTWAIT);
269 if (dmat->lowaddr < ptoa(Maxmem)) {
273 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
275 /* Initialize the new map */
276 STAILQ_INIT(&((*mapp)->bpages));
278 * Attempt to add pages to our pool on a per-instance
279 * basis up to a sane limit.
281 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
282 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
283 || (dmat->map_count > 0
284 && total_bpages < maxpages)) {
287 if (dmat->lowaddr > bounce_lowaddr) {
289 * Go through the pool and kill any pages
290 * that don't reside below lowaddr.
292 panic("bus_dmamap_create: page reallocation "
296 pages = MAX(atop(dmat->maxsize), 1);
297 pages = MIN(maxpages - total_bpages, pages);
298 pages = MAX(pages, 1);
299 if (alloc_bounce_pages(dmat, pages) < pages)
302 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
304 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
318 * Destroy a handle for mapping from kva/uva/physical
319 * address space into bus device space.
322 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
325 if (STAILQ_FIRST(&map->bpages) != NULL)
327 kfree(map, M_DEVBUF);
334 * Allocate a piece of memory that can be efficiently mapped into
335 * bus device space based on the constraints lited in the dma tag.
337 * mapp is degenerate. By definition this allocation should not require
338 * bounce buffers so do not allocate a dma map.
341 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
346 /* If we succeed, no mapping/bouncing will be required */
349 if (dmat->segments == NULL) {
350 KKASSERT(dmat->nsegments < 16384);
351 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
352 dmat->nsegments, M_DEVBUF, M_INTWAIT);
355 if (flags & BUS_DMA_NOWAIT)
359 if (flags & BUS_DMA_ZERO)
362 if ((dmat->maxsize <= PAGE_SIZE) &&
363 dmat->lowaddr >= ptoa(Maxmem)) {
364 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
366 * XXX Check whether the allocation crossed a page boundary
367 * and retry with power-of-2 alignment in that case.
369 if ((((intptr_t)*vaddr) & PAGE_MASK) !=
370 (((intptr_t)*vaddr + dmat->maxsize) & PAGE_MASK)) {
373 kfree(*vaddr, M_DEVBUF);
374 /* XXX check for overflow? */
375 for (size = 1; size <= dmat->maxsize; size <<= 1)
377 *vaddr = kmalloc(size, M_DEVBUF, mflags);
381 * XXX Use Contigmalloc until it is merged into this facility
382 * and handles multi-seg allocations. Nobody is doing
383 * multi-seg allocations yet though.
385 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
386 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
395 * Free a piece of memory and it's allociated dmamap, that was allocated
396 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
399 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
402 * dmamem does not need to be bounced, so the map should be
406 panic("bus_dmamem_free: Invalid map freed\n");
407 if ((dmat->maxsize <= PAGE_SIZE) &&
408 dmat->lowaddr >= ptoa(Maxmem))
409 kfree(vaddr, M_DEVBUF);
411 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
414 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
417 * Map the buffer buf into bus space using the dmamap map.
420 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
421 bus_size_t buflen, bus_dmamap_callback_t *callback,
422 void *callback_arg, int flags)
425 vm_paddr_t paddr, nextpaddr;
426 bus_dma_segment_t *sg;
431 map = &nobounce_dmamap;
435 * If we are being called during a callback, pagesneeded will
436 * be non-zero, so we can avoid doing the work twice.
438 if (dmat->lowaddr < ptoa(Maxmem) &&
439 map->pagesneeded == 0) {
440 vm_offset_t vendaddr;
443 * Count the number of bounce pages
444 * needed in order to complete this transfer
446 vaddr = trunc_page((vm_offset_t)buf);
447 vendaddr = (vm_offset_t)buf + buflen;
449 while (vaddr < vendaddr) {
450 paddr = pmap_kextract(vaddr);
451 if (run_filter(dmat, paddr) != 0)
457 /* Reserve Necessary Bounce Pages */
458 if (map->pagesneeded != 0) {
460 if (reserve_bounce_pages(dmat, map) != 0) {
461 /* Queue us for resources */
464 map->buflen = buflen;
465 map->callback = callback;
466 map->callback_arg = callback_arg;
468 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
471 return (EINPROGRESS);
476 vaddr = (vm_offset_t)buf;
481 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */
483 /* force at least one segment */
490 paddr = pmap_kextract(vaddr);
491 size = PAGE_SIZE - (paddr & PAGE_MASK);
494 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
496 * note: this paddr has the same in-page offset
497 * as vaddr and thus the paddr above, so the
498 * size does not have to be recalculated
500 paddr = add_bounce_page(dmat, map, vaddr, size);
504 * Fill in the bus_dma_segment
506 if (sg->ds_len == 0) {
509 } else if (paddr == nextpaddr) {
514 if (seg > dmat->nsegments)
519 nextpaddr = paddr + size;
522 * Handle maxsegsz and boundary issues with a nested loop
528 * Limit to the boundary and maximum segment size
530 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
531 tmpsize = dmat->boundary -
532 (sg->ds_addr & ~bmask);
533 if (tmpsize > dmat->maxsegsz)
534 tmpsize = dmat->maxsegsz;
535 KKASSERT(tmpsize < sg->ds_len);
536 } else if (sg->ds_len > dmat->maxsegsz) {
537 tmpsize = dmat->maxsegsz;
543 * Futz, split the data into a new segment.
545 if (seg >= dmat->nsegments)
547 sg[1].ds_len = sg[0].ds_len - tmpsize;
548 sg[1].ds_addr = sg[0].ds_addr + tmpsize;
549 sg[0].ds_len = tmpsize;
559 } while (buflen > 0);
563 kprintf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
568 (*callback)(callback_arg, dmat->segments, seg, error);
574 * Utility function to load a linear buffer. lastaddrp holds state
575 * between invocations (for multiple-buffer loads). segp contains
576 * the starting segment on entrace, and the ending segment on exit.
577 * first indicates if this is the first invocation of this function.
580 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
581 void *buf, bus_size_t buflen,
584 vm_offset_t *lastaddrp,
588 bus_dma_segment_t *segs;
590 bus_addr_t curaddr, lastaddr, baddr, bmask;
591 vm_offset_t vaddr = (vm_offset_t)buf;
595 if (td->td_proc != NULL)
596 pmap = vmspace_pmap(td->td_proc->p_vmspace);
600 segs = dmat->segments;
601 lastaddr = *lastaddrp;
602 bmask = ~(dmat->boundary - 1);
604 for (seg = *segp; buflen > 0 ; ) {
606 * Get the physical address for this segment.
609 curaddr = pmap_extract(pmap, vaddr);
611 curaddr = pmap_kextract(vaddr);
614 * Compute the segment size, and adjust counts.
616 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
621 * Make sure we don't cross any boundaries.
623 if (dmat->boundary > 0) {
624 baddr = (curaddr + dmat->boundary) & bmask;
625 if (sgsize > (baddr - curaddr))
626 sgsize = (baddr - curaddr);
630 * Insert chunk into a segment, coalescing with
631 * previous segment if possible.
634 segs[seg].ds_addr = curaddr;
635 segs[seg].ds_len = sgsize;
638 if (curaddr == lastaddr &&
639 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
640 (dmat->boundary == 0 ||
641 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
642 segs[seg].ds_len += sgsize;
644 if (++seg >= dmat->nsegments)
646 segs[seg].ds_addr = curaddr;
647 segs[seg].ds_len = sgsize;
651 lastaddr = curaddr + sgsize;
657 *lastaddrp = lastaddr;
662 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
666 * Like _bus_dmamap_load(), but for mbufs.
669 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
671 bus_dmamap_callback2_t *callback, void *callback_arg,
676 KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
677 ("bus_dmamap_load_mbuf: No support for bounce pages!"));
678 KASSERT(m0->m_flags & M_PKTHDR,
679 ("bus_dmamap_load_mbuf: no packet header"));
683 if (m0->m_pkthdr.len <= dmat->maxsize) {
685 vm_offset_t lastaddr = 0;
688 for (m = m0; m != NULL && error == 0; m = m->m_next) {
691 error = _bus_dmamap_load_buffer(dmat,
693 curthread, flags, &lastaddr,
702 /* force "no valid mappings" in callback */
703 (*callback)(callback_arg, dmat->segments, 0, 0, error);
705 (*callback)(callback_arg, dmat->segments,
706 nsegs+1, m0->m_pkthdr.len, error);
712 * Like _bus_dmamap_load(), but for uios.
715 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
717 bus_dmamap_callback2_t *callback, void *callback_arg,
720 vm_offset_t lastaddr;
721 int nsegs, error, first, i;
724 struct thread *td = NULL;
726 KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
727 ("bus_dmamap_load_uio: No support for bounce pages!"));
729 resid = uio->uio_resid;
732 if (uio->uio_segflg == UIO_USERSPACE) {
734 KASSERT(td != NULL && td->td_proc != NULL,
735 ("bus_dmamap_load_uio: USERSPACE but no proc"));
741 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
743 * Now at the first iovec to load. Load each iovec
744 * until we have exhausted the residual count.
747 resid < iov[i].iov_len ? resid : iov[i].iov_len;
748 caddr_t addr = (caddr_t) iov[i].iov_base;
750 error = _bus_dmamap_load_buffer(dmat,
752 td, flags, &lastaddr, &nsegs, first);
759 /* force "no valid mappings" in callback */
760 (*callback)(callback_arg, dmat->segments, 0, 0, error);
762 (*callback)(callback_arg, dmat->segments,
763 nsegs+1, uio->uio_resid, error);
769 * Release the mapping held by map.
772 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
774 struct bounce_page *bpage;
776 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
777 STAILQ_REMOVE_HEAD(&map->bpages, links);
778 free_bounce_page(dmat, bpage);
783 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
785 struct bounce_page *bpage;
787 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
789 * Handle data bouncing. We might also
790 * want to add support for invalidating
791 * the caches on broken hardware
794 case BUS_DMASYNC_PREWRITE:
795 while (bpage != NULL) {
796 bcopy((void *)bpage->datavaddr,
797 (void *)bpage->vaddr,
799 bpage = STAILQ_NEXT(bpage, links);
803 case BUS_DMASYNC_POSTREAD:
804 while (bpage != NULL) {
805 bcopy((void *)bpage->vaddr,
806 (void *)bpage->datavaddr,
808 bpage = STAILQ_NEXT(bpage, links);
812 case BUS_DMASYNC_PREREAD:
813 case BUS_DMASYNC_POSTWRITE:
821 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
826 if (total_bpages == 0) {
827 STAILQ_INIT(&bounce_page_list);
828 STAILQ_INIT(&bounce_map_waitinglist);
829 STAILQ_INIT(&bounce_map_callbacklist);
832 while (numpages > 0) {
833 struct bounce_page *bpage;
835 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
837 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
842 if (bpage->vaddr == 0) {
843 kfree(bpage, M_DEVBUF);
846 bpage->busaddr = pmap_kextract(bpage->vaddr);
848 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
859 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
863 pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
864 free_bpages -= pages;
865 reserved_bpages += pages;
866 map->pagesreserved += pages;
867 pages = map->pagesneeded - map->pagesreserved;
873 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
876 struct bounce_page *bpage;
878 if (map->pagesneeded == 0)
879 panic("add_bounce_page: map doesn't need any pages");
882 if (map->pagesreserved == 0)
883 panic("add_bounce_page: map doesn't need any pages");
884 map->pagesreserved--;
887 bpage = STAILQ_FIRST(&bounce_page_list);
889 panic("add_bounce_page: free page list is empty");
891 STAILQ_REMOVE_HEAD(&bounce_page_list, links);
896 bpage->datavaddr = vaddr;
897 bpage->datacount = size;
898 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
899 return (bpage->busaddr);
903 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
905 struct bus_dmamap *map;
907 bpage->datavaddr = 0;
908 bpage->datacount = 0;
911 STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
914 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
915 if (reserve_bounce_pages(map->dmat, map) == 0) {
916 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
917 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
919 busdma_swi_pending = 1;
929 struct bus_dmamap *map;
932 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
933 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
935 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
936 map->callback, map->callback_arg, /*flags*/0);