1 /*-
2 * Copyright (c) 1997, 1998 Justin T. Gibbs.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/7.3/sys/amd64/amd64/busdma_machdep.c 200289 2009-12-09 08:16:12Z scottl $");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/malloc.h>
33 #include <sys/bus.h>
34 #include <sys/interrupt.h>
35 #include <sys/kernel.h>
36 #include <sys/ktr.h>
37 #include <sys/lock.h>
38 #include <sys/proc.h>
39 #include <sys/mutex.h>
40 #include <sys/mbuf.h>
41 #include <sys/uio.h>
42 #include <sys/sysctl.h>
43
44 #include <vm/vm.h>
45 #include <vm/vm_page.h>
46 #include <vm/vm_map.h>
47
48 #include <machine/atomic.h>
49 #include <machine/bus.h>
50 #include <machine/md_var.h>
51 #include <machine/specialreg.h>
52
53 #define MAX_BPAGES 8192
54
55 struct bounce_zone;
56
57 struct bus_dma_tag {
58 bus_dma_tag_t parent;
59 bus_size_t alignment;
60 bus_size_t boundary;
61 bus_addr_t lowaddr;
62 bus_addr_t highaddr;
63 bus_dma_filter_t *filter;
64 void *filterarg;
65 bus_size_t maxsize;
66 u_int nsegments;
67 bus_size_t maxsegsz;
68 int flags;
69 int ref_count;
70 int map_count;
71 bus_dma_lock_t *lockfunc;
72 void *lockfuncarg;
73 bus_dma_segment_t *segments;
74 struct bounce_zone *bounce_zone;
75 };
76
77 struct bounce_page {
78 vm_offset_t vaddr; /* kva of bounce buffer */
79 bus_addr_t busaddr; /* Physical address */
80 vm_offset_t datavaddr; /* kva of client data */
81 bus_size_t datacount; /* client data count */
82 STAILQ_ENTRY(bounce_page) links;
83 };
84
85 int busdma_swi_pending;
86
87 struct bounce_zone {
88 STAILQ_ENTRY(bounce_zone) links;
89 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
90 int total_bpages;
91 int free_bpages;
92 int reserved_bpages;
93 int active_bpages;
94 int total_bounced;
95 int total_deferred;
96 bus_size_t alignment;
97 bus_addr_t lowaddr;
98 char zoneid[8];
99 char lowaddrid[20];
100 struct sysctl_ctx_list sysctl_tree;
101 struct sysctl_oid *sysctl_tree_top;
102 };
103
104 static struct mtx bounce_lock;
105 static int total_bpages;
106 static int busdma_zonecount;
107 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
108
109 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
110 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
111 "Total bounce pages");
112
113 struct bus_dmamap {
114 struct bp_list bpages;
115 int pagesneeded;
116 int pagesreserved;
117 bus_dma_tag_t dmat;
118 void *buf; /* unmapped buffer pointer */
119 bus_size_t buflen; /* unmapped buffer length */
120 bus_dmamap_callback_t *callback;
121 void *callback_arg;
122 STAILQ_ENTRY(bus_dmamap) links;
123 };
124
125 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
126 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
127 static struct bus_dmamap nobounce_dmamap;
128
129 static void init_bounce_pages(void *dummy);
130 static int alloc_bounce_zone(bus_dma_tag_t dmat);
131 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
132 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
133 int commit);
134 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
135 vm_offset_t vaddr, bus_size_t size);
136 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
137 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
138
139 /*
140 * Return true if a match is made.
141 *
142 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
143 *
144 * If paddr is within the bounds of the dma tag then call the filter callback
145 * to check for a match, if there is no filter callback then assume a match.
146 */
147 static __inline int
148 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
149 {
150 int retval;
151
152 retval = 0;
153
154 do {
155 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
156 || ((paddr & (dmat->alignment - 1)) != 0))
157 && (dmat->filter == NULL
158 || (*dmat->filter)(dmat->filterarg, paddr) != 0))
159 retval = 1;
160
161 dmat = dmat->parent;
162 } while (retval == 0 && dmat != NULL);
163 return (retval);
164 }
165
166 /*
167 * Convenience function for manipulating driver locks from busdma (during
168 * busdma_swi, for example). Drivers that don't provide their own locks
169 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own
170 * non-mutex locking scheme don't have to use this at all.
171 */
172 void
173 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
174 {
175 struct mtx *dmtx;
176
177 dmtx = (struct mtx *)arg;
178 switch (op) {
179 case BUS_DMA_LOCK:
180 mtx_lock(dmtx);
181 break;
182 case BUS_DMA_UNLOCK:
183 mtx_unlock(dmtx);
184 break;
185 default:
186 panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
187 }
188 }
189
190 /*
191 * dflt_lock should never get called. It gets put into the dma tag when
192 * lockfunc == NULL, which is only valid if the maps that are associated
193 * with the tag are meant to never be defered.
194 * XXX Should have a way to identify which driver is responsible here.
195 */
196 static void
197 dflt_lock(void *arg, bus_dma_lock_op_t op)
198 {
199 panic("driver error: busdma dflt_lock called");
200 }
201
202 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3
203 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
204 /*
205 * Allocate a device specific dma_tag.
206 */
207 int
208 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
209 bus_size_t boundary, bus_addr_t lowaddr,
210 bus_addr_t highaddr, bus_dma_filter_t *filter,
211 void *filterarg, bus_size_t maxsize, int nsegments,
212 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
213 void *lockfuncarg, bus_dma_tag_t *dmat)
214 {
215 bus_dma_tag_t newtag;
216 int error = 0;
217
218 /* Basic sanity checking */
219 if (boundary != 0 && boundary < maxsegsz)
220 maxsegsz = boundary;
221
222 if (maxsegsz == 0) {
223 return (EINVAL);
224 }
225
226 /* Return a NULL tag on failure */
227 *dmat = NULL;
228
229 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF,
230 M_ZERO | M_NOWAIT);
231 if (newtag == NULL) {
232 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
233 __func__, newtag, 0, error);
234 return (ENOMEM);
235 }
236
237 newtag->parent = parent;
238 newtag->alignment = alignment;
239 newtag->boundary = boundary;
240 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
241 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) +
242 (PAGE_SIZE - 1);
243 newtag->filter = filter;
244 newtag->filterarg = filterarg;
245 newtag->maxsize = maxsize;
246 newtag->nsegments = nsegments;
247 newtag->maxsegsz = maxsegsz;
248 newtag->flags = flags;
249 newtag->ref_count = 1; /* Count ourself */
250 newtag->map_count = 0;
251 if (lockfunc != NULL) {
252 newtag->lockfunc = lockfunc;
253 newtag->lockfuncarg = lockfuncarg;
254 } else {
255 newtag->lockfunc = dflt_lock;
256 newtag->lockfuncarg = NULL;
257 }
258 newtag->segments = NULL;
259
260 /* Take into account any restrictions imposed by our parent tag */
261 if (parent != NULL) {
262 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
263 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
264 if (newtag->boundary == 0)
265 newtag->boundary = parent->boundary;
266 else if (parent->boundary != 0)
267 newtag->boundary = MIN(parent->boundary,
268 newtag->boundary);
269 if (newtag->filter == NULL) {
270 /*
271 * Short circuit looking at our parent directly
272 * since we have encapsulated all of its information
273 */
274 newtag->filter = parent->filter;
275 newtag->filterarg = parent->filterarg;
276 newtag->parent = parent->parent;
277 }
278 if (newtag->parent != NULL)
279 atomic_add_int(&parent->ref_count, 1);
280 }
281
282 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem)
283 || newtag->alignment > 1)
284 newtag->flags |= BUS_DMA_COULD_BOUNCE;
285
286 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
287 (flags & BUS_DMA_ALLOCNOW) != 0) {
288 struct bounce_zone *bz;
289
290 /* Must bounce */
291
292 if ((error = alloc_bounce_zone(newtag)) != 0) {
293 free(newtag, M_DEVBUF);
294 return (error);
295 }
296 bz = newtag->bounce_zone;
297
298 if (ptoa(bz->total_bpages) < maxsize) {
299 int pages;
300
301 pages = atop(maxsize) - bz->total_bpages;
302
303 /* Add pages to our bounce pool */
304 if (alloc_bounce_pages(newtag, pages) < pages)
305 error = ENOMEM;
306 }
307 /* Performed initial allocation */
308 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
309 }
310
311 if (error != 0) {
312 free(newtag, M_DEVBUF);
313 } else {
314 *dmat = newtag;
315 }
316 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
317 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
318 return (error);
319 }
320
321 int
322 bus_dma_tag_destroy(bus_dma_tag_t dmat)
323 {
324 bus_dma_tag_t dmat_copy;
325 int error;
326
327 error = 0;
328 dmat_copy = dmat;
329
330 if (dmat != NULL) {
331
332 if (dmat->map_count != 0) {
333 error = EBUSY;
334 goto out;
335 }
336
337 while (dmat != NULL) {
338 bus_dma_tag_t parent;
339
340 parent = dmat->parent;
341 atomic_subtract_int(&dmat->ref_count, 1);
342 if (dmat->ref_count == 0) {
343 if (dmat->segments != NULL)
344 free(dmat->segments, M_DEVBUF);
345 free(dmat, M_DEVBUF);
346 /*
347 * Last reference count, so
348 * release our reference
349 * count on our parent.
350 */
351 dmat = parent;
352 } else
353 dmat = NULL;
354 }
355 }
356 out:
357 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
358 return (error);
359 }
360
361 /*
362 * Allocate a handle for mapping from kva/uva/physical
363 * address space into bus device space.
364 */
365 int
366 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
367 {
368 int error;
369
370 error = 0;
371
372 if (dmat->segments == NULL) {
373 dmat->segments = (bus_dma_segment_t *)malloc(
374 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
375 M_NOWAIT);
376 if (dmat->segments == NULL) {
377 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
378 __func__, dmat, ENOMEM);
379 return (ENOMEM);
380 }
381 }
382
383 /*
384 * Bouncing might be required if the driver asks for an active
385 * exclusion region, a data alignment that is stricter than 1, and/or
386 * an active address boundary.
387 */
388 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
389
390 /* Must bounce */
391 struct bounce_zone *bz;
392 int maxpages;
393
394 if (dmat->bounce_zone == NULL) {
395 if ((error = alloc_bounce_zone(dmat)) != 0)
396 return (error);
397 }
398 bz = dmat->bounce_zone;
399
400 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
401 M_NOWAIT | M_ZERO);
402 if (*mapp == NULL) {
403 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
404 __func__, dmat, ENOMEM);
405 return (ENOMEM);
406 }
407
408 /* Initialize the new map */
409 STAILQ_INIT(&((*mapp)->bpages));
410
411 /*
412 * Attempt to add pages to our pool on a per-instance
413 * basis up to a sane limit.
414 */
415 if (dmat->alignment > 1)
416 maxpages = MAX_BPAGES;
417 else
418 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr));
419 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
420 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
421 int pages;
422
423 pages = MAX(atop(dmat->maxsize), 1);
424 pages = MIN(maxpages - bz->total_bpages, pages);
425 pages = MAX(pages, 1);
426 if (alloc_bounce_pages(dmat, pages) < pages)
427 error = ENOMEM;
428
429 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
430 if (error == 0)
431 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
432 } else {
433 error = 0;
434 }
435 }
436 } else {
437 *mapp = NULL;
438 }
439 if (error == 0)
440 dmat->map_count++;
441 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
442 __func__, dmat, dmat->flags, error);
443 return (error);
444 }
445
446 /*
447 * Destroy a handle for mapping from kva/uva/physical
448 * address space into bus device space.
449 */
450 int
451 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
452 {
453 if (map != NULL && map != &nobounce_dmamap) {
454 if (STAILQ_FIRST(&map->bpages) != NULL) {
455 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
456 __func__, dmat, EBUSY);
457 return (EBUSY);
458 }
459 free(map, M_DEVBUF);
460 }
461 dmat->map_count--;
462 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
463 return (0);
464 }
465
466
467 /*
468 * Allocate a piece of memory that can be efficiently mapped into
469 * bus device space based on the constraints lited in the dma tag.
470 * A dmamap to for use with dmamap_load is also allocated.
471 */
472 int
473 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
474 bus_dmamap_t *mapp)
475 {
476 int mflags;
477
478 if (flags & BUS_DMA_NOWAIT)
479 mflags = M_NOWAIT;
480 else
481 mflags = M_WAITOK;
482 if (flags & BUS_DMA_ZERO)
483 mflags |= M_ZERO;
484
485 /* If we succeed, no mapping/bouncing will be required */
486 *mapp = NULL;
487
488 if (dmat->segments == NULL) {
489 dmat->segments = (bus_dma_segment_t *)malloc(
490 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
491 M_NOWAIT);
492 if (dmat->segments == NULL) {
493 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
494 __func__, dmat, dmat->flags, ENOMEM);
495 return (ENOMEM);
496 }
497 }
498
499 /*
500 * XXX:
501 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
502 * alignment guarantees of malloc need to be nailed down, and the
503 * code below should be rewritten to take that into account.
504 *
505 * In the meantime, we'll warn the user if malloc gets it wrong.
506 */
507 if ((dmat->maxsize <= PAGE_SIZE) &&
508 (dmat->alignment < dmat->maxsize) &&
509 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
510 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
511 } else {
512 /*
513 * XXX Use Contigmalloc until it is merged into this facility
514 * and handles multi-seg allocations. Nobody is doing
515 * multi-seg allocations yet though.
516 * XXX Certain AGP hardware does.
517 */
518 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
519 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
520 dmat->boundary);
521 }
522 if (*vaddr == NULL) {
523 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
524 __func__, dmat, dmat->flags, ENOMEM);
525 return (ENOMEM);
526 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) {
527 printf("bus_dmamem_alloc failed to align memory properly.\n");
528 }
529 if (flags & BUS_DMA_NOCACHE)
530 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize,
531 PAT_UNCACHEABLE);
532 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
533 __func__, dmat, dmat->flags, ENOMEM);
534 return (0);
535 }
536
537 /*
538 * Free a piece of memory and it's allociated dmamap, that was allocated
539 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
540 */
541 void
542 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
543 {
544 /*
545 * dmamem does not need to be bounced, so the map should be
546 * NULL
547 */
548 if (map != NULL)
549 panic("bus_dmamem_free: Invalid map freed\n");
550 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK);
551 if ((dmat->maxsize <= PAGE_SIZE) &&
552 (dmat->alignment < dmat->maxsize) &&
553 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
554 free(vaddr, M_DEVBUF);
555 else {
556 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
557 }
558 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
559 }
560
561 /*
562 * Utility function to load a linear buffer. lastaddrp holds state
563 * between invocations (for multiple-buffer loads). segp contains
564 * the starting segment on entrace, and the ending segment on exit.
565 * first indicates if this is the first invocation of this function.
566 */
567 static __inline int
568 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
569 bus_dmamap_t map,
570 void *buf, bus_size_t buflen,
571 pmap_t pmap,
572 int flags,
573 bus_addr_t *lastaddrp,
574 bus_dma_segment_t *segs,
575 int *segp,
576 int first)
577 {
578 bus_size_t sgsize;
579 bus_addr_t curaddr, lastaddr, baddr, bmask;
580 vm_offset_t vaddr;
581 bus_addr_t paddr;
582 int seg;
583
584 if (map == NULL)
585 map = &nobounce_dmamap;
586
587 if ((map != &nobounce_dmamap && map->pagesneeded == 0)
588 && ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0)) {
589 vm_offset_t vendaddr;
590
591 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
592 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
593 dmat->boundary, dmat->alignment);
594 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
595 map, &nobounce_dmamap, map->pagesneeded);
596 /*
597 * Count the number of bounce pages
598 * needed in order to complete this transfer
599 */
600 vaddr = (vm_offset_t)buf;
601 vendaddr = (vm_offset_t)buf + buflen;
602
603 while (vaddr < vendaddr) {
604 if (pmap)
605 paddr = pmap_extract(pmap, vaddr);
606 else
607 paddr = pmap_kextract(vaddr);
608 if (run_filter(dmat, paddr) != 0)
609 map->pagesneeded++;
610 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
611 }
612 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
613 }
614
615 /* Reserve Necessary Bounce Pages */
616 if (map->pagesneeded != 0) {
617 mtx_lock(&bounce_lock);
618 if (flags & BUS_DMA_NOWAIT) {
619 if (reserve_bounce_pages(dmat, map, 0) != 0) {
620 mtx_unlock(&bounce_lock);
621 return (ENOMEM);
622 }
623 } else {
624 if (reserve_bounce_pages(dmat, map, 1) != 0) {
625 /* Queue us for resources */
626 map->dmat = dmat;
627 map->buf = buf;
628 map->buflen = buflen;
629 STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
630 map, links);
631 mtx_unlock(&bounce_lock);
632 return (EINPROGRESS);
633 }
634 }
635 mtx_unlock(&bounce_lock);
636 }
637
638 vaddr = (vm_offset_t)buf;
639 lastaddr = *lastaddrp;
640 bmask = ~(dmat->boundary - 1);
641
642 for (seg = *segp; buflen > 0 ; ) {
643 /*
644 * Get the physical address for this segment.
645 */
646 if (pmap)
647 curaddr = pmap_extract(pmap, vaddr);
648 else
649 curaddr = pmap_kextract(vaddr);
650
651 /*
652 * Compute the segment size, and adjust counts.
653 */
654 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
655 if (sgsize > dmat->maxsegsz)
656 sgsize = dmat->maxsegsz;
657 if (buflen < sgsize)
658 sgsize = buflen;
659
660 /*
661 * Make sure we don't cross any boundaries.
662 */
663 if (dmat->boundary > 0) {
664 baddr = (curaddr + dmat->boundary) & bmask;
665 if (sgsize > (baddr - curaddr))
666 sgsize = (baddr - curaddr);
667 }
668
669 if (map->pagesneeded != 0 && run_filter(dmat, curaddr))
670 curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
671
672 /*
673 * Insert chunk into a segment, coalescing with
674 * previous segment if possible.
675 */
676 if (first) {
677 segs[seg].ds_addr = curaddr;
678 segs[seg].ds_len = sgsize;
679 first = 0;
680 } else {
681 if (curaddr == lastaddr &&
682 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
683 (dmat->boundary == 0 ||
684 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
685 segs[seg].ds_len += sgsize;
686 else {
687 if (++seg >= dmat->nsegments)
688 break;
689 segs[seg].ds_addr = curaddr;
690 segs[seg].ds_len = sgsize;
691 }
692 }
693
694 lastaddr = curaddr + sgsize;
695 vaddr += sgsize;
696 buflen -= sgsize;
697 }
698
699 *segp = seg;
700 *lastaddrp = lastaddr;
701
702 /*
703 * Did we fit?
704 */
705 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
706 }
707
708 /*
709 * Map the buffer buf into bus space using the dmamap map.
710 */
711 int
712 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
713 bus_size_t buflen, bus_dmamap_callback_t *callback,
714 void *callback_arg, int flags)
715 {
716 bus_addr_t lastaddr = 0;
717 int error, nsegs = 0;
718
719 if (map != NULL) {
720 flags |= BUS_DMA_WAITOK;
721 map->callback = callback;
722 map->callback_arg = callback_arg;
723 }
724
725 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
726 &lastaddr, dmat->segments, &nsegs, 1);
727
728 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
729 __func__, dmat, dmat->flags, error, nsegs + 1);
730
731 if (error == EINPROGRESS) {
732 return (error);
733 }
734
735 if (error)
736 (*callback)(callback_arg, dmat->segments, 0, error);
737 else
738 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
739
740 /*
741 * Return ENOMEM to the caller so that it can pass it up the stack.
742 * This error only happens when NOWAIT is set, so deferal is disabled.
743 */
744 if (error == ENOMEM)
745 return (error);
746
747 return (0);
748 }
749
750
751 /*
752 * Like _bus_dmamap_load(), but for mbufs.
753 */
754 int
755 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
756 struct mbuf *m0,
757 bus_dmamap_callback2_t *callback, void *callback_arg,
758 int flags)
759 {
760 int nsegs, error;
761
762 M_ASSERTPKTHDR(m0);
763
764 flags |= BUS_DMA_NOWAIT;
765 nsegs = 0;
766 error = 0;
767 if (m0->m_pkthdr.len <= dmat->maxsize) {
768 int first = 1;
769 bus_addr_t lastaddr = 0;
770 struct mbuf *m;
771
772 for (m = m0; m != NULL && error == 0; m = m->m_next) {
773 if (m->m_len > 0) {
774 error = _bus_dmamap_load_buffer(dmat, map,
775 m->m_data, m->m_len,
776 NULL, flags, &lastaddr,
777 dmat->segments, &nsegs, first);
778 first = 0;
779 }
780 }
781 } else {
782 error = EINVAL;
783 }
784
785 if (error) {
786 /* force "no valid mappings" in callback */
787 (*callback)(callback_arg, dmat->segments, 0, 0, error);
788 } else {
789 (*callback)(callback_arg, dmat->segments,
790 nsegs+1, m0->m_pkthdr.len, error);
791 }
792 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
793 __func__, dmat, dmat->flags, error, nsegs + 1);
794 return (error);
795 }
796
797 int
798 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
799 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
800 int flags)
801 {
802 int error;
803
804 M_ASSERTPKTHDR(m0);
805
806 flags |= BUS_DMA_NOWAIT;
807 *nsegs = 0;
808 error = 0;
809 if (m0->m_pkthdr.len <= dmat->maxsize) {
810 int first = 1;
811 bus_addr_t lastaddr = 0;
812 struct mbuf *m;
813
814 for (m = m0; m != NULL && error == 0; m = m->m_next) {
815 if (m->m_len > 0) {
816 error = _bus_dmamap_load_buffer(dmat, map,
817 m->m_data, m->m_len,
818 NULL, flags, &lastaddr,
819 segs, nsegs, first);
820 first = 0;
821 }
822 }
823 } else {
824 error = EINVAL;
825 }
826
827 /* XXX FIXME: Having to increment nsegs is really annoying */
828 ++*nsegs;
829 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
830 __func__, dmat, dmat->flags, error, *nsegs);
831 return (error);
832 }
833
834 /*
835 * Like _bus_dmamap_load(), but for uios.
836 */
837 int
838 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
839 struct uio *uio,
840 bus_dmamap_callback2_t *callback, void *callback_arg,
841 int flags)
842 {
843 bus_addr_t lastaddr = 0;
844 int nsegs, error, first, i;
845 bus_size_t resid;
846 struct iovec *iov;
847 pmap_t pmap;
848
849 flags |= BUS_DMA_NOWAIT;
850 resid = uio->uio_resid;
851 iov = uio->uio_iov;
852
853 if (uio->uio_segflg == UIO_USERSPACE) {
854 KASSERT(uio->uio_td != NULL,
855 ("bus_dmamap_load_uio: USERSPACE but no proc"));
856 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
857 } else
858 pmap = NULL;
859
860 nsegs = 0;
861 error = 0;
862 first = 1;
863 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
864 /*
865 * Now at the first iovec to load. Load each iovec
866 * until we have exhausted the residual count.
867 */
868 bus_size_t minlen =
869 resid < iov[i].iov_len ? resid : iov[i].iov_len;
870 caddr_t addr = (caddr_t) iov[i].iov_base;
871
872 if (minlen > 0) {
873 error = _bus_dmamap_load_buffer(dmat, map,
874 addr, minlen, pmap, flags, &lastaddr,
875 dmat->segments, &nsegs, first);
876 first = 0;
877
878 resid -= minlen;
879 }
880 }
881
882 if (error) {
883 /* force "no valid mappings" in callback */
884 (*callback)(callback_arg, dmat->segments, 0, 0, error);
885 } else {
886 (*callback)(callback_arg, dmat->segments,
887 nsegs+1, uio->uio_resid, error);
888 }
889 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
890 __func__, dmat, dmat->flags, error, nsegs + 1);
891 return (error);
892 }
893
894 /*
895 * Release the mapping held by map.
896 */
897 void
898 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
899 {
900 struct bounce_page *bpage;
901
902 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
903 STAILQ_REMOVE_HEAD(&map->bpages, links);
904 free_bounce_page(dmat, bpage);
905 }
906 }
907
908 void
909 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
910 {
911 struct bounce_page *bpage;
912
913 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
914 /*
915 * Handle data bouncing. We might also
916 * want to add support for invalidating
917 * the caches on broken hardware
918 */
919 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
920 "performing bounce", __func__, op, dmat, dmat->flags);
921
922 if (op & BUS_DMASYNC_PREWRITE) {
923 while (bpage != NULL) {
924 bcopy((void *)bpage->datavaddr,
925 (void *)bpage->vaddr,
926 bpage->datacount);
927 bpage = STAILQ_NEXT(bpage, links);
928 }
929 dmat->bounce_zone->total_bounced++;
930 }
931
932 if (op & BUS_DMASYNC_POSTREAD) {
933 while (bpage != NULL) {
934 bcopy((void *)bpage->vaddr,
935 (void *)bpage->datavaddr,
936 bpage->datacount);
937 bpage = STAILQ_NEXT(bpage, links);
938 }
939 dmat->bounce_zone->total_bounced++;
940 }
941 }
942 }
943
944 static void
945 init_bounce_pages(void *dummy __unused)
946 {
947
948 total_bpages = 0;
949 STAILQ_INIT(&bounce_zone_list);
950 STAILQ_INIT(&bounce_map_waitinglist);
951 STAILQ_INIT(&bounce_map_callbacklist);
952 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
953 }
954 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
955
956 static struct sysctl_ctx_list *
957 busdma_sysctl_tree(struct bounce_zone *bz)
958 {
959 return (&bz->sysctl_tree);
960 }
961
962 static struct sysctl_oid *
963 busdma_sysctl_tree_top(struct bounce_zone *bz)
964 {
965 return (bz->sysctl_tree_top);
966 }
967
968 static int
969 alloc_bounce_zone(bus_dma_tag_t dmat)
970 {
971 struct bounce_zone *bz;
972
973 /* Check to see if we already have a suitable zone */
974 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
975 if ((dmat->alignment <= bz->alignment)
976 && (dmat->lowaddr >= bz->lowaddr)) {
977 dmat->bounce_zone = bz;
978 return (0);
979 }
980 }
981
982 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
983 M_NOWAIT | M_ZERO)) == NULL)
984 return (ENOMEM);
985
986 STAILQ_INIT(&bz->bounce_page_list);
987 bz->free_bpages = 0;
988 bz->reserved_bpages = 0;
989 bz->active_bpages = 0;
990 bz->lowaddr = dmat->lowaddr;
991 bz->alignment = MAX(dmat->alignment, PAGE_SIZE);
992 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
993 busdma_zonecount++;
994 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
995 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
996 dmat->bounce_zone = bz;
997
998 sysctl_ctx_init(&bz->sysctl_tree);
999 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1000 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1001 CTLFLAG_RD, 0, "");
1002 if (bz->sysctl_tree_top == NULL) {
1003 sysctl_ctx_free(&bz->sysctl_tree);
1004 return (0); /* XXX error code? */
1005 }
1006
1007 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1008 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1009 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1010 "Total bounce pages");
1011 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1012 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1013 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1014 "Free bounce pages");
1015 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1016 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1017 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1018 "Reserved bounce pages");
1019 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1020 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1021 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1022 "Active bounce pages");
1023 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1024 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1025 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1026 "Total bounce requests");
1027 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1028 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1029 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1030 "Total bounce requests that were deferred");
1031 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1032 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1033 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1034 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1035 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1036 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1037
1038 return (0);
1039 }
1040
1041 static int
1042 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1043 {
1044 struct bounce_zone *bz;
1045 int count;
1046
1047 bz = dmat->bounce_zone;
1048 count = 0;
1049 while (numpages > 0) {
1050 struct bounce_page *bpage;
1051
1052 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1053 M_NOWAIT | M_ZERO);
1054
1055 if (bpage == NULL)
1056 break;
1057 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1058 M_NOWAIT, 0ul,
1059 bz->lowaddr,
1060 PAGE_SIZE,
1061 0);
1062 if (bpage->vaddr == 0) {
1063 free(bpage, M_DEVBUF);
1064 break;
1065 }
1066 bpage->busaddr = pmap_kextract(bpage->vaddr);
1067 mtx_lock(&bounce_lock);
1068 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1069 total_bpages++;
1070 bz->total_bpages++;
1071 bz->free_bpages++;
1072 mtx_unlock(&bounce_lock);
1073 count++;
1074 numpages--;
1075 }
1076 return (count);
1077 }
1078
1079 static int
1080 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1081 {
1082 struct bounce_zone *bz;
1083 int pages;
1084
1085 mtx_assert(&bounce_lock, MA_OWNED);
1086 bz = dmat->bounce_zone;
1087 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1088 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1089 return (map->pagesneeded - (map->pagesreserved + pages));
1090 bz->free_bpages -= pages;
1091 bz->reserved_bpages += pages;
1092 map->pagesreserved += pages;
1093 pages = map->pagesneeded - map->pagesreserved;
1094
1095 return (pages);
1096 }
1097
1098 static bus_addr_t
1099 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1100 bus_size_t size)
1101 {
1102 struct bounce_zone *bz;
1103 struct bounce_page *bpage;
1104
1105 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1106 KASSERT(map != NULL && map != &nobounce_dmamap,
1107 ("add_bounce_page: bad map %p", map));
1108
1109 bz = dmat->bounce_zone;
1110 if (map->pagesneeded == 0)
1111 panic("add_bounce_page: map doesn't need any pages");
1112 map->pagesneeded--;
1113
1114 if (map->pagesreserved == 0)
1115 panic("add_bounce_page: map doesn't need any pages");
1116 map->pagesreserved--;
1117
1118 mtx_lock(&bounce_lock);
1119 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1120 if (bpage == NULL)
1121 panic("add_bounce_page: free page list is empty");
1122
1123 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1124 bz->reserved_bpages--;
1125 bz->active_bpages++;
1126 mtx_unlock(&bounce_lock);
1127
1128 bpage->datavaddr = vaddr;
1129 bpage->datacount = size;
1130 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1131 return (bpage->busaddr);
1132 }
1133
1134 static void
1135 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1136 {
1137 struct bus_dmamap *map;
1138 struct bounce_zone *bz;
1139
1140 bz = dmat->bounce_zone;
1141 bpage->datavaddr = 0;
1142 bpage->datacount = 0;
1143
1144 mtx_lock(&bounce_lock);
1145 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1146 bz->free_bpages++;
1147 bz->active_bpages--;
1148 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1149 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1150 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1151 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1152 map, links);
1153 busdma_swi_pending = 1;
1154 bz->total_deferred++;
1155 swi_sched(vm_ih, 0);
1156 }
1157 }
1158 mtx_unlock(&bounce_lock);
1159 }
1160
1161 void
1162 busdma_swi(void)
1163 {
1164 bus_dma_tag_t dmat;
1165 struct bus_dmamap *map;
1166
1167 mtx_lock(&bounce_lock);
1168 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1169 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1170 mtx_unlock(&bounce_lock);
1171 dmat = map->dmat;
1172 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1173 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1174 map->callback, map->callback_arg, /*flags*/0);
1175 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1176 mtx_lock(&bounce_lock);
1177 }
1178 mtx_unlock(&bounce_lock);
1179 }
Cache object: a70f330d649318ddc15bccd6ee66d366
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