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("$FreeBSD$");
29
30 #include <sys/param.h>
31 #include <sys/kdb.h>
32 #include <ddb/ddb.h>
33 #include <ddb/db_output.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/bus.h>
37 #include <sys/interrupt.h>
38 #include <sys/kernel.h>
39 #include <sys/ktr.h>
40 #include <sys/lock.h>
41 #include <sys/proc.h>
42 #include <sys/mutex.h>
43 #include <sys/mbuf.h>
44 #include <sys/uio.h>
45 #include <sys/sysctl.h>
46
47 #include <vm/vm.h>
48 #include <vm/vm_page.h>
49 #include <vm/vm_map.h>
50
51 #include <machine/atomic.h>
52 #include <machine/bus.h>
53 #include <machine/md_var.h>
54 #include <machine/specialreg.h>
55
56 #define MAX_BPAGES 512
57 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3
58 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
59
60 struct bounce_zone;
61
62 struct bus_dma_tag {
63 bus_dma_tag_t parent;
64 bus_size_t alignment;
65 bus_size_t boundary;
66 bus_addr_t lowaddr;
67 bus_addr_t highaddr;
68 bus_dma_filter_t *filter;
69 void *filterarg;
70 bus_size_t maxsize;
71 u_int nsegments;
72 bus_size_t maxsegsz;
73 int flags;
74 int ref_count;
75 int map_count;
76 bus_dma_lock_t *lockfunc;
77 void *lockfuncarg;
78 bus_dma_segment_t *segments;
79 struct bounce_zone *bounce_zone;
80 };
81
82 struct bounce_page {
83 vm_offset_t vaddr; /* kva of bounce buffer */
84 bus_addr_t busaddr; /* Physical address */
85 vm_offset_t datavaddr; /* kva of client data */
86 bus_size_t datacount; /* client data count */
87 STAILQ_ENTRY(bounce_page) links;
88 };
89
90 int busdma_swi_pending;
91
92 struct bounce_zone {
93 STAILQ_ENTRY(bounce_zone) links;
94 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
95 int total_bpages;
96 int free_bpages;
97 int reserved_bpages;
98 int active_bpages;
99 int total_bounced;
100 int total_deferred;
101 bus_size_t alignment;
102 bus_addr_t lowaddr;
103 char zoneid[8];
104 char lowaddrid[20];
105 struct sysctl_ctx_list sysctl_tree;
106 struct sysctl_oid *sysctl_tree_top;
107 };
108
109 static struct mtx bounce_lock;
110 static int total_bpages;
111 static int busdma_zonecount;
112 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
113
114 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
115 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
116 "Total bounce pages");
117
118 struct bus_dmamap {
119 struct bp_list bpages;
120 int pagesneeded;
121 int pagesreserved;
122 bus_dma_tag_t dmat;
123 void *buf; /* unmapped buffer pointer */
124 bus_size_t buflen; /* unmapped buffer length */
125 bus_dmamap_callback_t *callback;
126 void *callback_arg;
127 STAILQ_ENTRY(bus_dmamap) links;
128 };
129
130 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
131 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
132 static struct bus_dmamap nobounce_dmamap;
133
134 static void init_bounce_pages(void *dummy);
135 static int alloc_bounce_zone(bus_dma_tag_t dmat);
136 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
137 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
138 int commit);
139 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
140 vm_offset_t vaddr, bus_size_t size);
141 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
142 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
143 int _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
144 void *buf, bus_size_t buflen, int flags);
145
146 /*
147 * Return true if a match is made.
148 *
149 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
150 *
151 * If paddr is within the bounds of the dma tag then call the filter callback
152 * to check for a match, if there is no filter callback then assume a match.
153 */
154 int
155 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
156 {
157 int retval;
158
159 retval = 0;
160
161 do {
162 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
163 || ((paddr & (dmat->alignment - 1)) != 0))
164 && (dmat->filter == NULL
165 || (*dmat->filter)(dmat->filterarg, paddr) != 0))
166 retval = 1;
167
168 dmat = dmat->parent;
169 } while (retval == 0 && dmat != NULL);
170 return (retval);
171 }
172
173 /*
174 * Convenience function for manipulating driver locks from busdma (during
175 * busdma_swi, for example). Drivers that don't provide their own locks
176 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own
177 * non-mutex locking scheme don't have to use this at all.
178 */
179 void
180 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
181 {
182 struct mtx *dmtx;
183
184 dmtx = (struct mtx *)arg;
185 switch (op) {
186 case BUS_DMA_LOCK:
187 mtx_lock(dmtx);
188 break;
189 case BUS_DMA_UNLOCK:
190 mtx_unlock(dmtx);
191 break;
192 default:
193 panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
194 }
195 }
196
197 /*
198 * dflt_lock should never get called. It gets put into the dma tag when
199 * lockfunc == NULL, which is only valid if the maps that are associated
200 * with the tag are meant to never be defered.
201 * XXX Should have a way to identify which driver is responsible here.
202 */
203 static void
204 dflt_lock(void *arg, bus_dma_lock_op_t op)
205 {
206 panic("driver error: busdma dflt_lock called");
207 }
208
209 /*
210 * Allocate a device specific dma_tag.
211 */
212 int
213 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
214 bus_size_t boundary, bus_addr_t lowaddr,
215 bus_addr_t highaddr, bus_dma_filter_t *filter,
216 void *filterarg, bus_size_t maxsize, int nsegments,
217 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
218 void *lockfuncarg, bus_dma_tag_t *dmat)
219 {
220 bus_dma_tag_t newtag;
221 int error = 0;
222
223 #if defined(PAE)
224 /* Need at least a 4GB boundary, PAE limitations require 2GB */
225 if (boundary == 0 || boundary > ((bus_addr_t)1 << 31))
226 boundary = (bus_size_t)1 << 31;
227 #endif
228
229 /* Basic sanity checking */
230 if (boundary != 0 && boundary < maxsegsz)
231 maxsegsz = boundary;
232
233 if (maxsegsz == 0) {
234 return (EINVAL);
235 }
236
237 /* Return a NULL tag on failure */
238 *dmat = NULL;
239
240 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF,
241 M_ZERO | M_NOWAIT);
242 if (newtag == NULL) {
243 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
244 __func__, newtag, 0, error);
245 return (ENOMEM);
246 }
247
248 newtag->parent = parent;
249 newtag->alignment = alignment;
250 newtag->boundary = boundary;
251 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
252 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) +
253 (PAGE_SIZE - 1);
254 newtag->filter = filter;
255 newtag->filterarg = filterarg;
256 newtag->maxsize = maxsize;
257 newtag->nsegments = nsegments;
258 newtag->maxsegsz = maxsegsz;
259 newtag->flags = flags;
260 newtag->ref_count = 1; /* Count ourself */
261 newtag->map_count = 0;
262 if (lockfunc != NULL) {
263 newtag->lockfunc = lockfunc;
264 newtag->lockfuncarg = lockfuncarg;
265 } else {
266 newtag->lockfunc = dflt_lock;
267 newtag->lockfuncarg = NULL;
268 }
269 newtag->segments = NULL;
270
271 /* Take into account any restrictions imposed by our parent tag */
272 if (parent != NULL) {
273 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
274 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
275 if (newtag->boundary == 0)
276 newtag->boundary = parent->boundary;
277 else if (parent->boundary != 0)
278 newtag->boundary = MIN(parent->boundary,
279 newtag->boundary);
280 if ((newtag->filter != NULL) ||
281 ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
282 newtag->flags |= BUS_DMA_COULD_BOUNCE;
283 if (newtag->filter == NULL) {
284 /*
285 * Short circuit looking at our parent directly
286 * since we have encapsulated all of its information
287 */
288 newtag->filter = parent->filter;
289 newtag->filterarg = parent->filterarg;
290 newtag->parent = parent->parent;
291 }
292 if (newtag->parent != NULL)
293 atomic_add_int(&parent->ref_count, 1);
294 }
295
296 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem)
297 || newtag->alignment > 1)
298 newtag->flags |= BUS_DMA_COULD_BOUNCE;
299
300 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
301 (flags & BUS_DMA_ALLOCNOW) != 0) {
302 struct bounce_zone *bz;
303
304 /* Must bounce */
305
306 if ((error = alloc_bounce_zone(newtag)) != 0) {
307 free(newtag, M_DEVBUF);
308 return (error);
309 }
310 bz = newtag->bounce_zone;
311
312 if (ptoa(bz->total_bpages) < maxsize) {
313 int pages;
314
315 pages = atop(maxsize) - bz->total_bpages;
316
317 /* Add pages to our bounce pool */
318 if (alloc_bounce_pages(newtag, pages) < pages)
319 error = ENOMEM;
320 }
321 /* Performed initial allocation */
322 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
323 }
324
325 if (error != 0) {
326 free(newtag, M_DEVBUF);
327 } else {
328 *dmat = newtag;
329 }
330 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
331 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
332 return (error);
333 }
334
335 int
336 bus_dma_tag_destroy(bus_dma_tag_t dmat)
337 {
338 bus_dma_tag_t dmat_copy;
339 int error;
340
341 error = 0;
342 dmat_copy = dmat;
343
344 if (dmat != NULL) {
345
346 if (dmat->map_count != 0) {
347 error = EBUSY;
348 goto out;
349 }
350
351 while (dmat != NULL) {
352 bus_dma_tag_t parent;
353
354 parent = dmat->parent;
355 atomic_subtract_int(&dmat->ref_count, 1);
356 if (dmat->ref_count == 0) {
357 if (dmat->segments != NULL)
358 free(dmat->segments, M_DEVBUF);
359 free(dmat, M_DEVBUF);
360 /*
361 * Last reference count, so
362 * release our reference
363 * count on our parent.
364 */
365 dmat = parent;
366 } else
367 dmat = NULL;
368 }
369 }
370 out:
371 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
372 return (error);
373 }
374
375 /*
376 * Allocate a handle for mapping from kva/uva/physical
377 * address space into bus device space.
378 */
379 int
380 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
381 {
382 int error;
383
384 error = 0;
385
386 if (dmat->segments == NULL) {
387 dmat->segments = (bus_dma_segment_t *)malloc(
388 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
389 M_NOWAIT);
390 if (dmat->segments == NULL) {
391 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
392 __func__, dmat, ENOMEM);
393 return (ENOMEM);
394 }
395 }
396
397 /*
398 * Bouncing might be required if the driver asks for an active
399 * exclusion region, a data alignment that is stricter than 1, and/or
400 * an active address boundary.
401 */
402 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
403
404 /* Must bounce */
405 struct bounce_zone *bz;
406 int maxpages;
407
408 if (dmat->bounce_zone == NULL) {
409 if ((error = alloc_bounce_zone(dmat)) != 0)
410 return (error);
411 }
412 bz = dmat->bounce_zone;
413
414 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
415 M_NOWAIT | M_ZERO);
416 if (*mapp == NULL) {
417 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
418 __func__, dmat, ENOMEM);
419 return (ENOMEM);
420 }
421
422 /* Initialize the new map */
423 STAILQ_INIT(&((*mapp)->bpages));
424
425 /*
426 * Attempt to add pages to our pool on a per-instance
427 * basis up to a sane limit.
428 */
429 if (dmat->alignment > 1)
430 maxpages = MAX_BPAGES;
431 else
432 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr));
433 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
434 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
435 int pages;
436
437 pages = MAX(atop(dmat->maxsize), 1);
438 pages = MIN(maxpages - bz->total_bpages, pages);
439 pages = MAX(pages, 1);
440 if (alloc_bounce_pages(dmat, pages) < pages)
441 error = ENOMEM;
442
443 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
444 if (error == 0)
445 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
446 } else {
447 error = 0;
448 }
449 }
450 } else {
451 *mapp = NULL;
452 }
453 if (error == 0)
454 dmat->map_count++;
455 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
456 __func__, dmat, dmat->flags, error);
457 return (error);
458 }
459
460 /*
461 * Destroy a handle for mapping from kva/uva/physical
462 * address space into bus device space.
463 */
464 int
465 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
466 {
467 if (map != NULL && map != &nobounce_dmamap) {
468 if (STAILQ_FIRST(&map->bpages) != NULL) {
469 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
470 __func__, dmat, EBUSY);
471 return (EBUSY);
472 }
473 free(map, M_DEVBUF);
474 }
475 dmat->map_count--;
476 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
477 return (0);
478 }
479
480
481 /*
482 * Allocate a piece of memory that can be efficiently mapped into
483 * bus device space based on the constraints lited in the dma tag.
484 * A dmamap to for use with dmamap_load is also allocated.
485 */
486 int
487 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
488 bus_dmamap_t *mapp)
489 {
490 int mflags;
491
492 if (flags & BUS_DMA_NOWAIT)
493 mflags = M_NOWAIT;
494 else
495 mflags = M_WAITOK;
496 if (flags & BUS_DMA_ZERO)
497 mflags |= M_ZERO;
498
499 /* If we succeed, no mapping/bouncing will be required */
500 *mapp = NULL;
501
502 if (dmat->segments == NULL) {
503 dmat->segments = (bus_dma_segment_t *)malloc(
504 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
505 M_NOWAIT);
506 if (dmat->segments == NULL) {
507 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
508 __func__, dmat, dmat->flags, ENOMEM);
509 return (ENOMEM);
510 }
511 }
512
513 /*
514 * XXX:
515 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
516 * alignment guarantees of malloc need to be nailed down, and the
517 * code below should be rewritten to take that into account.
518 *
519 * In the meantime, we'll warn the user if malloc gets it wrong.
520 */
521 if ((dmat->maxsize <= PAGE_SIZE) &&
522 (dmat->alignment < dmat->maxsize) &&
523 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
524 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
525 } else {
526 /*
527 * XXX Use Contigmalloc until it is merged into this facility
528 * and handles multi-seg allocations. Nobody is doing
529 * multi-seg allocations yet though.
530 * XXX Certain AGP hardware does.
531 */
532 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
533 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
534 dmat->boundary);
535 }
536 if (*vaddr == NULL) {
537 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
538 __func__, dmat, dmat->flags, ENOMEM);
539 return (ENOMEM);
540 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) {
541 printf("bus_dmamem_alloc failed to align memory properly.\n");
542 }
543 if (flags & BUS_DMA_NOCACHE)
544 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize,
545 PAT_UNCACHEABLE);
546 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
547 __func__, dmat, dmat->flags, ENOMEM);
548 return (0);
549 }
550
551 /*
552 * Free a piece of memory and it's allociated dmamap, that was allocated
553 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
554 */
555 void
556 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
557 {
558 /*
559 * dmamem does not need to be bounced, so the map should be
560 * NULL
561 */
562 if (map != NULL)
563 panic("bus_dmamem_free: Invalid map freed\n");
564 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK);
565 if ((dmat->maxsize <= PAGE_SIZE) &&
566 (dmat->alignment < dmat->maxsize) &&
567 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
568 free(vaddr, M_DEVBUF);
569 else {
570 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
571 }
572 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
573 }
574
575 int
576 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
577 void *buf, bus_size_t buflen, int flags)
578 {
579 vm_offset_t vaddr;
580 vm_offset_t vendaddr;
581 bus_addr_t paddr;
582
583 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
584 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
585 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
586 dmat->boundary, dmat->alignment);
587 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
588 map, &nobounce_dmamap, map->pagesneeded);
589 /*
590 * Count the number of bounce pages
591 * needed in order to complete this transfer
592 */
593 vaddr = (vm_offset_t)buf;
594 vendaddr = (vm_offset_t)buf + buflen;
595
596 while (vaddr < vendaddr) {
597 if (pmap)
598 paddr = pmap_extract(pmap, vaddr);
599 else
600 paddr = pmap_kextract(vaddr);
601 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
602 run_filter(dmat, paddr) != 0) {
603 map->pagesneeded++;
604 }
605 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
606 }
607 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
608 }
609
610 /* Reserve Necessary Bounce Pages */
611 if (map->pagesneeded != 0) {
612 mtx_lock(&bounce_lock);
613 if (flags & BUS_DMA_NOWAIT) {
614 if (reserve_bounce_pages(dmat, map, 0) != 0) {
615 mtx_unlock(&bounce_lock);
616 return (ENOMEM);
617 }
618 } else {
619 if (reserve_bounce_pages(dmat, map, 1) != 0) {
620 /* Queue us for resources */
621 map->dmat = dmat;
622 map->buf = buf;
623 map->buflen = buflen;
624 STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
625 map, links);
626 mtx_unlock(&bounce_lock);
627 return (EINPROGRESS);
628 }
629 }
630 mtx_unlock(&bounce_lock);
631 }
632
633 return (0);
634 }
635
636 /*
637 * Utility function to load a linear buffer. lastaddrp holds state
638 * between invocations (for multiple-buffer loads). segp contains
639 * the starting segment on entrace, and the ending segment on exit.
640 * first indicates if this is the first invocation of this function.
641 */
642 static __inline int
643 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
644 bus_dmamap_t map,
645 void *buf, bus_size_t buflen,
646 pmap_t pmap,
647 int flags,
648 bus_addr_t *lastaddrp,
649 bus_dma_segment_t *segs,
650 int *segp,
651 int first)
652 {
653 bus_size_t sgsize;
654 bus_addr_t curaddr, lastaddr, baddr, bmask;
655 vm_offset_t vaddr;
656 int seg, error;
657
658 if (map == NULL)
659 map = &nobounce_dmamap;
660
661 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
662 error = _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
663 if (error)
664 return (error);
665 }
666
667 vaddr = (vm_offset_t)buf;
668 lastaddr = *lastaddrp;
669 bmask = ~(dmat->boundary - 1);
670
671 for (seg = *segp; buflen > 0 ; ) {
672 /*
673 * Get the physical address for this segment.
674 */
675 if (pmap)
676 curaddr = pmap_extract(pmap, vaddr);
677 else
678 curaddr = pmap_kextract(vaddr);
679
680 /*
681 * Compute the segment size, and adjust counts.
682 */
683 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
684 if (sgsize > dmat->maxsegsz)
685 sgsize = dmat->maxsegsz;
686 if (buflen < sgsize)
687 sgsize = buflen;
688
689 /*
690 * Make sure we don't cross any boundaries.
691 */
692 if (dmat->boundary > 0) {
693 baddr = (curaddr + dmat->boundary) & bmask;
694 if (sgsize > (baddr - curaddr))
695 sgsize = (baddr - curaddr);
696 }
697
698 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
699 map->pagesneeded != 0 && run_filter(dmat, curaddr))
700 curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
701
702 /*
703 * Insert chunk into a segment, coalescing with
704 * previous segment if possible.
705 */
706 if (first) {
707 segs[seg].ds_addr = curaddr;
708 segs[seg].ds_len = sgsize;
709 first = 0;
710 } else {
711 if (curaddr == lastaddr &&
712 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
713 (dmat->boundary == 0 ||
714 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
715 segs[seg].ds_len += sgsize;
716 else {
717 if (++seg >= dmat->nsegments)
718 break;
719 segs[seg].ds_addr = curaddr;
720 segs[seg].ds_len = sgsize;
721 }
722 }
723
724 lastaddr = curaddr + sgsize;
725 vaddr += sgsize;
726 buflen -= sgsize;
727 }
728
729 *segp = seg;
730 *lastaddrp = lastaddr;
731
732 /*
733 * Did we fit?
734 */
735 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
736 }
737
738 /*
739 * Map the buffer buf into bus space using the dmamap map.
740 */
741 int
742 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
743 bus_size_t buflen, bus_dmamap_callback_t *callback,
744 void *callback_arg, int flags)
745 {
746 bus_addr_t lastaddr = 0;
747 int error, nsegs = 0;
748
749 if (map != NULL) {
750 flags |= BUS_DMA_WAITOK;
751 map->callback = callback;
752 map->callback_arg = callback_arg;
753 }
754
755 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
756 &lastaddr, dmat->segments, &nsegs, 1);
757
758 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
759 __func__, dmat, dmat->flags, error, nsegs + 1);
760
761 if (error == EINPROGRESS) {
762 return (error);
763 }
764
765 if (error)
766 (*callback)(callback_arg, dmat->segments, 0, error);
767 else
768 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
769
770 /*
771 * Return ENOMEM to the caller so that it can pass it up the stack.
772 * This error only happens when NOWAIT is set, so deferal is disabled.
773 */
774 if (error == ENOMEM)
775 return (error);
776
777 return (0);
778 }
779
780
781 /*
782 * Like _bus_dmamap_load(), but for mbufs.
783 */
784 static __inline int
785 _bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
786 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
787 int flags)
788 {
789 int error;
790
791 M_ASSERTPKTHDR(m0);
792
793 flags |= BUS_DMA_NOWAIT;
794 *nsegs = 0;
795 error = 0;
796 if (m0->m_pkthdr.len <= dmat->maxsize) {
797 int first = 1;
798 bus_addr_t lastaddr = 0;
799 struct mbuf *m;
800
801 for (m = m0; m != NULL && error == 0; m = m->m_next) {
802 if (m->m_len > 0) {
803 error = _bus_dmamap_load_buffer(dmat, map,
804 m->m_data, m->m_len,
805 NULL, flags, &lastaddr,
806 segs, nsegs, first);
807 first = 0;
808 }
809 }
810 } else {
811 error = EINVAL;
812 }
813
814 /* XXX FIXME: Having to increment nsegs is really annoying */
815 ++*nsegs;
816 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
817 __func__, dmat, dmat->flags, error, *nsegs);
818 return (error);
819 }
820
821 int
822 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
823 struct mbuf *m0,
824 bus_dmamap_callback2_t *callback, void *callback_arg,
825 int flags)
826 {
827 int nsegs, error;
828
829 error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, dmat->segments, &nsegs,
830 flags);
831
832 if (error) {
833 /* force "no valid mappings" in callback */
834 (*callback)(callback_arg, dmat->segments, 0, 0, error);
835 } else {
836 (*callback)(callback_arg, dmat->segments,
837 nsegs, m0->m_pkthdr.len, error);
838 }
839 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
840 __func__, dmat, dmat->flags, error, nsegs);
841 return (error);
842 }
843
844 int
845 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
846 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
847 int flags)
848 {
849 return (_bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags));
850 }
851
852 /*
853 * Like _bus_dmamap_load(), but for uios.
854 */
855 int
856 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
857 struct uio *uio,
858 bus_dmamap_callback2_t *callback, void *callback_arg,
859 int flags)
860 {
861 bus_addr_t lastaddr;
862 int nsegs, error, first, i;
863 bus_size_t resid;
864 struct iovec *iov;
865 pmap_t pmap;
866
867 flags |= BUS_DMA_NOWAIT;
868 resid = uio->uio_resid;
869 iov = uio->uio_iov;
870
871 if (uio->uio_segflg == UIO_USERSPACE) {
872 KASSERT(uio->uio_td != NULL,
873 ("bus_dmamap_load_uio: USERSPACE but no proc"));
874 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
875 } else
876 pmap = NULL;
877
878 nsegs = 0;
879 error = 0;
880 first = 1;
881 lastaddr = (bus_addr_t) 0;
882 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
883 /*
884 * Now at the first iovec to load. Load each iovec
885 * until we have exhausted the residual count.
886 */
887 bus_size_t minlen =
888 resid < iov[i].iov_len ? resid : iov[i].iov_len;
889 caddr_t addr = (caddr_t) iov[i].iov_base;
890
891 if (minlen > 0) {
892 error = _bus_dmamap_load_buffer(dmat, map,
893 addr, minlen, pmap, flags, &lastaddr,
894 dmat->segments, &nsegs, first);
895 first = 0;
896
897 resid -= minlen;
898 }
899 }
900
901 if (error) {
902 /* force "no valid mappings" in callback */
903 (*callback)(callback_arg, dmat->segments, 0, 0, error);
904 } else {
905 (*callback)(callback_arg, dmat->segments,
906 nsegs+1, uio->uio_resid, error);
907 }
908 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
909 __func__, dmat, dmat->flags, error, nsegs + 1);
910 return (error);
911 }
912
913 /*
914 * Release the mapping held by map.
915 */
916 void
917 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
918 {
919 struct bounce_page *bpage;
920
921 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
922 STAILQ_REMOVE_HEAD(&map->bpages, links);
923 free_bounce_page(dmat, bpage);
924 }
925 }
926
927 void
928 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
929 {
930 struct bounce_page *bpage;
931
932 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
933 /*
934 * Handle data bouncing. We might also
935 * want to add support for invalidating
936 * the caches on broken hardware
937 */
938 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
939 "performing bounce", __func__, op, dmat, dmat->flags);
940
941 if (op & BUS_DMASYNC_PREWRITE) {
942 while (bpage != NULL) {
943 bcopy((void *)bpage->datavaddr,
944 (void *)bpage->vaddr,
945 bpage->datacount);
946 bpage = STAILQ_NEXT(bpage, links);
947 }
948 dmat->bounce_zone->total_bounced++;
949 }
950
951 if (op & BUS_DMASYNC_POSTREAD) {
952 while (bpage != NULL) {
953 bcopy((void *)bpage->vaddr,
954 (void *)bpage->datavaddr,
955 bpage->datacount);
956 bpage = STAILQ_NEXT(bpage, links);
957 }
958 dmat->bounce_zone->total_bounced++;
959 }
960 }
961 }
962
963 static void
964 init_bounce_pages(void *dummy __unused)
965 {
966
967 total_bpages = 0;
968 STAILQ_INIT(&bounce_zone_list);
969 STAILQ_INIT(&bounce_map_waitinglist);
970 STAILQ_INIT(&bounce_map_callbacklist);
971 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
972 }
973 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
974
975 static struct sysctl_ctx_list *
976 busdma_sysctl_tree(struct bounce_zone *bz)
977 {
978 return (&bz->sysctl_tree);
979 }
980
981 static struct sysctl_oid *
982 busdma_sysctl_tree_top(struct bounce_zone *bz)
983 {
984 return (bz->sysctl_tree_top);
985 }
986
987 static int
988 alloc_bounce_zone(bus_dma_tag_t dmat)
989 {
990 struct bounce_zone *bz;
991
992 /* Check to see if we already have a suitable zone */
993 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
994 if ((dmat->alignment <= bz->alignment)
995 && (dmat->lowaddr >= bz->lowaddr)) {
996 dmat->bounce_zone = bz;
997 return (0);
998 }
999 }
1000
1001 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1002 M_NOWAIT | M_ZERO)) == NULL)
1003 return (ENOMEM);
1004
1005 STAILQ_INIT(&bz->bounce_page_list);
1006 bz->free_bpages = 0;
1007 bz->reserved_bpages = 0;
1008 bz->active_bpages = 0;
1009 bz->lowaddr = dmat->lowaddr;
1010 bz->alignment = MAX(dmat->alignment, PAGE_SIZE);
1011 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1012 busdma_zonecount++;
1013 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1014 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1015 dmat->bounce_zone = bz;
1016
1017 sysctl_ctx_init(&bz->sysctl_tree);
1018 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1019 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1020 CTLFLAG_RD, 0, "");
1021 if (bz->sysctl_tree_top == NULL) {
1022 sysctl_ctx_free(&bz->sysctl_tree);
1023 return (0); /* XXX error code? */
1024 }
1025
1026 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1027 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1028 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1029 "Total bounce pages");
1030 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1031 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1032 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1033 "Free bounce pages");
1034 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1035 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1036 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1037 "Reserved bounce pages");
1038 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1039 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1040 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1041 "Active bounce pages");
1042 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1043 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1044 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1045 "Total bounce requests");
1046 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1047 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1048 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1049 "Total bounce requests that were deferred");
1050 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1051 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1052 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1053 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1054 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1055 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1056
1057 return (0);
1058 }
1059
1060 static int
1061 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1062 {
1063 struct bounce_zone *bz;
1064 int count;
1065
1066 bz = dmat->bounce_zone;
1067 count = 0;
1068 while (numpages > 0) {
1069 struct bounce_page *bpage;
1070
1071 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1072 M_NOWAIT | M_ZERO);
1073
1074 if (bpage == NULL)
1075 break;
1076 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1077 M_NOWAIT, 0ul,
1078 bz->lowaddr,
1079 PAGE_SIZE,
1080 0);
1081 if (bpage->vaddr == 0) {
1082 free(bpage, M_DEVBUF);
1083 break;
1084 }
1085 bpage->busaddr = pmap_kextract(bpage->vaddr);
1086 mtx_lock(&bounce_lock);
1087 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1088 total_bpages++;
1089 bz->total_bpages++;
1090 bz->free_bpages++;
1091 mtx_unlock(&bounce_lock);
1092 count++;
1093 numpages--;
1094 }
1095 return (count);
1096 }
1097
1098 static int
1099 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1100 {
1101 struct bounce_zone *bz;
1102 int pages;
1103
1104 mtx_assert(&bounce_lock, MA_OWNED);
1105 bz = dmat->bounce_zone;
1106 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1107 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1108 return (map->pagesneeded - (map->pagesreserved + pages));
1109 bz->free_bpages -= pages;
1110 bz->reserved_bpages += pages;
1111 map->pagesreserved += pages;
1112 pages = map->pagesneeded - map->pagesreserved;
1113
1114 return (pages);
1115 }
1116
1117 static bus_addr_t
1118 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1119 bus_size_t size)
1120 {
1121 struct bounce_zone *bz;
1122 struct bounce_page *bpage;
1123
1124 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1125 KASSERT(map != NULL && map != &nobounce_dmamap,
1126 ("add_bounce_page: bad map %p", map));
1127
1128 bz = dmat->bounce_zone;
1129 if (map->pagesneeded == 0)
1130 panic("add_bounce_page: map doesn't need any pages");
1131 map->pagesneeded--;
1132
1133 if (map->pagesreserved == 0)
1134 panic("add_bounce_page: map doesn't need any pages");
1135 map->pagesreserved--;
1136
1137 mtx_lock(&bounce_lock);
1138 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1139 if (bpage == NULL)
1140 panic("add_bounce_page: free page list is empty");
1141
1142 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1143 bz->reserved_bpages--;
1144 bz->active_bpages++;
1145 mtx_unlock(&bounce_lock);
1146
1147 bpage->datavaddr = vaddr;
1148 bpage->datacount = size;
1149 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1150 return (bpage->busaddr);
1151 }
1152
1153 static void
1154 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1155 {
1156 struct bus_dmamap *map;
1157 struct bounce_zone *bz;
1158
1159 bz = dmat->bounce_zone;
1160 bpage->datavaddr = 0;
1161 bpage->datacount = 0;
1162
1163 mtx_lock(&bounce_lock);
1164 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1165 bz->free_bpages++;
1166 bz->active_bpages--;
1167 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1168 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1169 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1170 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1171 map, links);
1172 busdma_swi_pending = 1;
1173 bz->total_deferred++;
1174 swi_sched(vm_ih, 0);
1175 }
1176 }
1177 mtx_unlock(&bounce_lock);
1178 }
1179
1180 void
1181 busdma_swi(void)
1182 {
1183 bus_dma_tag_t dmat;
1184 struct bus_dmamap *map;
1185
1186 mtx_lock(&bounce_lock);
1187 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1188 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1189 mtx_unlock(&bounce_lock);
1190 dmat = map->dmat;
1191 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1192 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1193 map->callback, map->callback_arg, /*flags*/0);
1194 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1195 mtx_lock(&bounce_lock);
1196 }
1197 mtx_unlock(&bounce_lock);
1198 }
Cache object: 62e11b6425de42209e48a3d1bf5d3d66
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