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/8.3/sys/i386/i386/busdma_machdep.c 232354 2012-03-01 19:43:28Z emaste $");
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 int map_count;
102 bus_size_t alignment;
103 bus_addr_t lowaddr;
104 char zoneid[8];
105 char lowaddrid[20];
106 struct sysctl_ctx_list sysctl_tree;
107 struct sysctl_oid *sysctl_tree_top;
108 };
109
110 static struct mtx bounce_lock;
111 static int total_bpages;
112 static int busdma_zonecount;
113 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
114
115 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
116 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
117 "Total bounce pages");
118
119 struct bus_dmamap {
120 struct bp_list bpages;
121 int pagesneeded;
122 int pagesreserved;
123 bus_dma_tag_t dmat;
124 void *buf; /* unmapped buffer pointer */
125 bus_size_t buflen; /* unmapped buffer length */
126 bus_dmamap_callback_t *callback;
127 void *callback_arg;
128 STAILQ_ENTRY(bus_dmamap) links;
129 };
130
131 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
132 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
133 static struct bus_dmamap nobounce_dmamap;
134
135 static void init_bounce_pages(void *dummy);
136 static int alloc_bounce_zone(bus_dma_tag_t dmat);
137 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
138 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
139 int commit);
140 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
141 vm_offset_t vaddr, bus_size_t size);
142 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
143 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
144 int _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
145 void *buf, bus_size_t buflen, int flags);
146
147 #ifdef XEN
148 #undef pmap_kextract
149 #define pmap_kextract pmap_kextract_ma
150 #endif
151
152 /*
153 * Return true if a match is made.
154 *
155 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
156 *
157 * If paddr is within the bounds of the dma tag then call the filter callback
158 * to check for a match, if there is no filter callback then assume a match.
159 */
160 int
161 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
162 {
163 int retval;
164
165 retval = 0;
166
167 do {
168 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
169 || ((paddr & (dmat->alignment - 1)) != 0))
170 && (dmat->filter == NULL
171 || (*dmat->filter)(dmat->filterarg, paddr) != 0))
172 retval = 1;
173
174 dmat = dmat->parent;
175 } while (retval == 0 && dmat != NULL);
176 return (retval);
177 }
178
179 /*
180 * Convenience function for manipulating driver locks from busdma (during
181 * busdma_swi, for example). Drivers that don't provide their own locks
182 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own
183 * non-mutex locking scheme don't have to use this at all.
184 */
185 void
186 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
187 {
188 struct mtx *dmtx;
189
190 dmtx = (struct mtx *)arg;
191 switch (op) {
192 case BUS_DMA_LOCK:
193 mtx_lock(dmtx);
194 break;
195 case BUS_DMA_UNLOCK:
196 mtx_unlock(dmtx);
197 break;
198 default:
199 panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
200 }
201 }
202
203 /*
204 * dflt_lock should never get called. It gets put into the dma tag when
205 * lockfunc == NULL, which is only valid if the maps that are associated
206 * with the tag are meant to never be defered.
207 * XXX Should have a way to identify which driver is responsible here.
208 */
209 static void
210 dflt_lock(void *arg, bus_dma_lock_op_t op)
211 {
212 panic("driver error: busdma dflt_lock called");
213 }
214
215 /*
216 * Allocate a device specific dma_tag.
217 */
218 int
219 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
220 bus_size_t boundary, bus_addr_t lowaddr,
221 bus_addr_t highaddr, bus_dma_filter_t *filter,
222 void *filterarg, bus_size_t maxsize, int nsegments,
223 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
224 void *lockfuncarg, bus_dma_tag_t *dmat)
225 {
226 bus_dma_tag_t newtag;
227 int error = 0;
228
229 #if defined(PAE)
230 /* Need at least a 4GB boundary, PAE limitations require 2GB */
231 if (boundary == 0 || boundary > ((bus_addr_t)1 << 31))
232 boundary = (bus_size_t)1 << 31;
233 #endif
234
235 /* Basic sanity checking */
236 if (boundary != 0 && boundary < maxsegsz)
237 maxsegsz = boundary;
238
239 if (maxsegsz == 0) {
240 return (EINVAL);
241 }
242
243 /* Return a NULL tag on failure */
244 *dmat = NULL;
245
246 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF,
247 M_ZERO | M_NOWAIT);
248 if (newtag == NULL) {
249 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
250 __func__, newtag, 0, error);
251 return (ENOMEM);
252 }
253
254 newtag->parent = parent;
255 newtag->alignment = alignment;
256 newtag->boundary = boundary;
257 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
258 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
259 newtag->filter = filter;
260 newtag->filterarg = filterarg;
261 newtag->maxsize = maxsize;
262 newtag->nsegments = nsegments;
263 newtag->maxsegsz = maxsegsz;
264 newtag->flags = flags;
265 newtag->ref_count = 1; /* Count ourself */
266 newtag->map_count = 0;
267 if (lockfunc != NULL) {
268 newtag->lockfunc = lockfunc;
269 newtag->lockfuncarg = lockfuncarg;
270 } else {
271 newtag->lockfunc = dflt_lock;
272 newtag->lockfuncarg = NULL;
273 }
274 newtag->segments = NULL;
275
276 /* Take into account any restrictions imposed by our parent tag */
277 if (parent != NULL) {
278 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
279 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
280 if (newtag->boundary == 0)
281 newtag->boundary = parent->boundary;
282 else if (parent->boundary != 0)
283 newtag->boundary = MIN(parent->boundary,
284 newtag->boundary);
285 if ((newtag->filter != NULL) ||
286 ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
287 newtag->flags |= BUS_DMA_COULD_BOUNCE;
288 if (newtag->filter == NULL) {
289 /*
290 * Short circuit looking at our parent directly
291 * since we have encapsulated all of its information
292 */
293 newtag->filter = parent->filter;
294 newtag->filterarg = parent->filterarg;
295 newtag->parent = parent->parent;
296 }
297 if (newtag->parent != NULL)
298 atomic_add_int(&parent->ref_count, 1);
299 }
300
301 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem)
302 || newtag->alignment > 1)
303 newtag->flags |= BUS_DMA_COULD_BOUNCE;
304
305 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
306 (flags & BUS_DMA_ALLOCNOW) != 0) {
307 struct bounce_zone *bz;
308
309 /* Must bounce */
310
311 if ((error = alloc_bounce_zone(newtag)) != 0) {
312 free(newtag, M_DEVBUF);
313 return (error);
314 }
315 bz = newtag->bounce_zone;
316
317 if (ptoa(bz->total_bpages) < maxsize) {
318 int pages;
319
320 pages = atop(maxsize) - bz->total_bpages;
321
322 /* Add pages to our bounce pool */
323 if (alloc_bounce_pages(newtag, pages) < pages)
324 error = ENOMEM;
325 }
326 /* Performed initial allocation */
327 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
328 }
329
330 if (error != 0) {
331 free(newtag, M_DEVBUF);
332 } else {
333 *dmat = newtag;
334 }
335 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
336 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
337 return (error);
338 }
339
340 int
341 bus_dma_tag_destroy(bus_dma_tag_t dmat)
342 {
343 bus_dma_tag_t dmat_copy;
344 int error;
345
346 error = 0;
347 dmat_copy = dmat;
348
349 if (dmat != NULL) {
350
351 if (dmat->map_count != 0) {
352 error = EBUSY;
353 goto out;
354 }
355
356 while (dmat != NULL) {
357 bus_dma_tag_t parent;
358
359 parent = dmat->parent;
360 atomic_subtract_int(&dmat->ref_count, 1);
361 if (dmat->ref_count == 0) {
362 if (dmat->segments != NULL)
363 free(dmat->segments, M_DEVBUF);
364 free(dmat, M_DEVBUF);
365 /*
366 * Last reference count, so
367 * release our reference
368 * count on our parent.
369 */
370 dmat = parent;
371 } else
372 dmat = NULL;
373 }
374 }
375 out:
376 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
377 return (error);
378 }
379
380 /*
381 * Allocate a handle for mapping from kva/uva/physical
382 * address space into bus device space.
383 */
384 int
385 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
386 {
387 int error;
388
389 error = 0;
390
391 if (dmat->segments == NULL) {
392 dmat->segments = (bus_dma_segment_t *)malloc(
393 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
394 M_NOWAIT);
395 if (dmat->segments == NULL) {
396 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
397 __func__, dmat, ENOMEM);
398 return (ENOMEM);
399 }
400 }
401
402 /*
403 * Bouncing might be required if the driver asks for an active
404 * exclusion region, a data alignment that is stricter than 1, and/or
405 * an active address boundary.
406 */
407 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
408
409 /* Must bounce */
410 struct bounce_zone *bz;
411 int maxpages;
412
413 if (dmat->bounce_zone == NULL) {
414 if ((error = alloc_bounce_zone(dmat)) != 0)
415 return (error);
416 }
417 bz = dmat->bounce_zone;
418
419 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
420 M_NOWAIT | M_ZERO);
421 if (*mapp == NULL) {
422 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
423 __func__, dmat, ENOMEM);
424 return (ENOMEM);
425 }
426
427 /* Initialize the new map */
428 STAILQ_INIT(&((*mapp)->bpages));
429
430 /*
431 * Attempt to add pages to our pool on a per-instance
432 * basis up to a sane limit.
433 */
434 if (dmat->alignment > 1)
435 maxpages = MAX_BPAGES;
436 else
437 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr));
438 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
439 || (bz->map_count > 0 && bz->total_bpages < maxpages)) {
440 int pages;
441
442 pages = MAX(atop(dmat->maxsize), 1);
443 pages = MIN(maxpages - bz->total_bpages, pages);
444 pages = MAX(pages, 1);
445 if (alloc_bounce_pages(dmat, pages) < pages)
446 error = ENOMEM;
447
448 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
449 if (error == 0)
450 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
451 } else {
452 error = 0;
453 }
454 }
455 bz->map_count++;
456 } else {
457 *mapp = NULL;
458 }
459 if (error == 0)
460 dmat->map_count++;
461 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
462 __func__, dmat, dmat->flags, error);
463 return (error);
464 }
465
466 /*
467 * Destroy a handle for mapping from kva/uva/physical
468 * address space into bus device space.
469 */
470 int
471 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
472 {
473 if (map != NULL && map != &nobounce_dmamap) {
474 if (STAILQ_FIRST(&map->bpages) != NULL) {
475 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
476 __func__, dmat, EBUSY);
477 return (EBUSY);
478 }
479 if (dmat->bounce_zone)
480 dmat->bounce_zone->map_count--;
481 free(map, M_DEVBUF);
482 }
483 dmat->map_count--;
484 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
485 return (0);
486 }
487
488
489 /*
490 * Allocate a piece of memory that can be efficiently mapped into
491 * bus device space based on the constraints lited in the dma tag.
492 * A dmamap to for use with dmamap_load is also allocated.
493 */
494 int
495 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
496 bus_dmamap_t *mapp)
497 {
498 int mflags;
499
500 if (flags & BUS_DMA_NOWAIT)
501 mflags = M_NOWAIT;
502 else
503 mflags = M_WAITOK;
504
505 /* If we succeed, no mapping/bouncing will be required */
506 *mapp = NULL;
507
508 if (dmat->segments == NULL) {
509 dmat->segments = (bus_dma_segment_t *)malloc(
510 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
511 mflags);
512 if (dmat->segments == NULL) {
513 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
514 __func__, dmat, dmat->flags, ENOMEM);
515 return (ENOMEM);
516 }
517 }
518 if (flags & BUS_DMA_ZERO)
519 mflags |= M_ZERO;
520
521 /*
522 * XXX:
523 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
524 * alignment guarantees of malloc need to be nailed down, and the
525 * code below should be rewritten to take that into account.
526 *
527 * In the meantime, we'll warn the user if malloc gets it wrong.
528 */
529 if ((dmat->maxsize <= PAGE_SIZE) &&
530 (dmat->alignment < dmat->maxsize) &&
531 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
532 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
533 } else {
534 /*
535 * XXX Use Contigmalloc until it is merged into this facility
536 * and handles multi-seg allocations. Nobody is doing
537 * multi-seg allocations yet though.
538 * XXX Certain AGP hardware does.
539 */
540 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
541 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
542 dmat->boundary);
543 }
544 if (*vaddr == NULL) {
545 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
546 __func__, dmat, dmat->flags, ENOMEM);
547 return (ENOMEM);
548 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) {
549 printf("bus_dmamem_alloc failed to align memory properly.\n");
550 }
551 if (flags & BUS_DMA_NOCACHE)
552 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize,
553 PAT_UNCACHEABLE);
554 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
555 __func__, dmat, dmat->flags, 0);
556 return (0);
557 }
558
559 /*
560 * Free a piece of memory and it's allociated dmamap, that was allocated
561 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
562 */
563 void
564 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
565 {
566 /*
567 * dmamem does not need to be bounced, so the map should be
568 * NULL
569 */
570 if (map != NULL)
571 panic("bus_dmamem_free: Invalid map freed\n");
572 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK);
573 if ((dmat->maxsize <= PAGE_SIZE) &&
574 (dmat->alignment < dmat->maxsize) &&
575 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
576 free(vaddr, M_DEVBUF);
577 else {
578 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
579 }
580 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
581 }
582
583 int
584 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
585 void *buf, bus_size_t buflen, int flags)
586 {
587 vm_offset_t vaddr;
588 vm_offset_t vendaddr;
589 bus_addr_t paddr;
590
591 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
592 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
593 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
594 dmat->boundary, dmat->alignment);
595 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
596 map, &nobounce_dmamap, map->pagesneeded);
597 /*
598 * Count the number of bounce pages
599 * needed in order to complete this transfer
600 */
601 vaddr = (vm_offset_t)buf;
602 vendaddr = (vm_offset_t)buf + buflen;
603
604 while (vaddr < vendaddr) {
605 bus_size_t sg_len;
606
607 sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
608 if (pmap)
609 paddr = pmap_extract(pmap, vaddr);
610 else
611 paddr = pmap_kextract(vaddr);
612 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
613 run_filter(dmat, paddr) != 0) {
614 sg_len = roundup2(sg_len, dmat->alignment);
615 map->pagesneeded++;
616 }
617 vaddr += sg_len;
618 }
619 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
620 }
621
622 /* Reserve Necessary Bounce Pages */
623 if (map->pagesneeded != 0) {
624 mtx_lock(&bounce_lock);
625 if (flags & BUS_DMA_NOWAIT) {
626 if (reserve_bounce_pages(dmat, map, 0) != 0) {
627 mtx_unlock(&bounce_lock);
628 return (ENOMEM);
629 }
630 } else {
631 if (reserve_bounce_pages(dmat, map, 1) != 0) {
632 /* Queue us for resources */
633 map->dmat = dmat;
634 map->buf = buf;
635 map->buflen = buflen;
636 STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
637 map, links);
638 mtx_unlock(&bounce_lock);
639 return (EINPROGRESS);
640 }
641 }
642 mtx_unlock(&bounce_lock);
643 }
644
645 return (0);
646 }
647
648 /*
649 * Utility function to load a linear buffer. lastaddrp holds state
650 * between invocations (for multiple-buffer loads). segp contains
651 * the starting segment on entrace, and the ending segment on exit.
652 * first indicates if this is the first invocation of this function.
653 */
654 static __inline int
655 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
656 bus_dmamap_t map,
657 void *buf, bus_size_t buflen,
658 pmap_t pmap,
659 int flags,
660 bus_addr_t *lastaddrp,
661 bus_dma_segment_t *segs,
662 int *segp,
663 int first)
664 {
665 bus_size_t sgsize;
666 bus_addr_t curaddr, lastaddr, baddr, bmask;
667 vm_offset_t vaddr;
668 int seg, error;
669
670 if (map == NULL)
671 map = &nobounce_dmamap;
672
673 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
674 error = _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
675 if (error)
676 return (error);
677 }
678
679 vaddr = (vm_offset_t)buf;
680 lastaddr = *lastaddrp;
681 bmask = ~(dmat->boundary - 1);
682
683 for (seg = *segp; buflen > 0 ; ) {
684 bus_size_t max_sgsize;
685
686 /*
687 * Get the physical address for this segment.
688 */
689 if (pmap)
690 curaddr = pmap_extract(pmap, vaddr);
691 else
692 curaddr = pmap_kextract(vaddr);
693
694 /*
695 * Compute the segment size, and adjust counts.
696 */
697 max_sgsize = MIN(buflen, dmat->maxsegsz);
698 sgsize = PAGE_SIZE - ((vm_offset_t)curaddr & PAGE_MASK);
699 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
700 map->pagesneeded != 0 && run_filter(dmat, curaddr)) {
701 sgsize = roundup2(sgsize, dmat->alignment);
702 sgsize = MIN(sgsize, max_sgsize);
703 curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
704 } else {
705 sgsize = MIN(sgsize, max_sgsize);
706 }
707
708 /*
709 * Make sure we don't cross any boundaries.
710 */
711 if (dmat->boundary > 0) {
712 baddr = (curaddr + dmat->boundary) & bmask;
713 if (sgsize > (baddr - curaddr))
714 sgsize = (baddr - curaddr);
715 }
716
717 /*
718 * Insert chunk into a segment, coalescing with
719 * previous segment if possible.
720 */
721 if (first) {
722 segs[seg].ds_addr = curaddr;
723 segs[seg].ds_len = sgsize;
724 first = 0;
725 } else {
726 if (curaddr == lastaddr &&
727 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
728 (dmat->boundary == 0 ||
729 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
730 segs[seg].ds_len += sgsize;
731 else {
732 if (++seg >= dmat->nsegments)
733 break;
734 segs[seg].ds_addr = curaddr;
735 segs[seg].ds_len = sgsize;
736 }
737 }
738
739 lastaddr = curaddr + sgsize;
740 vaddr += sgsize;
741 buflen -= sgsize;
742 }
743
744 *segp = seg;
745 *lastaddrp = lastaddr;
746
747 /*
748 * Did we fit?
749 */
750 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
751 }
752
753 /*
754 * Map the buffer buf into bus space using the dmamap map.
755 */
756 int
757 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
758 bus_size_t buflen, bus_dmamap_callback_t *callback,
759 void *callback_arg, int flags)
760 {
761 bus_addr_t lastaddr = 0;
762 int error, nsegs = 0;
763
764 if (map != NULL) {
765 flags |= BUS_DMA_WAITOK;
766 map->callback = callback;
767 map->callback_arg = callback_arg;
768 }
769
770 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
771 &lastaddr, dmat->segments, &nsegs, 1);
772
773 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
774 __func__, dmat, dmat->flags, error, nsegs + 1);
775
776 if (error == EINPROGRESS) {
777 return (error);
778 }
779
780 if (error)
781 (*callback)(callback_arg, dmat->segments, 0, error);
782 else
783 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
784
785 /*
786 * Return ENOMEM to the caller so that it can pass it up the stack.
787 * This error only happens when NOWAIT is set, so deferal is disabled.
788 */
789 if (error == ENOMEM)
790 return (error);
791
792 return (0);
793 }
794
795
796 /*
797 * Like _bus_dmamap_load(), but for mbufs.
798 */
799 static __inline int
800 _bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
801 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
802 int flags)
803 {
804 int error;
805
806 M_ASSERTPKTHDR(m0);
807
808 flags |= BUS_DMA_NOWAIT;
809 *nsegs = 0;
810 error = 0;
811 if (m0->m_pkthdr.len <= dmat->maxsize) {
812 int first = 1;
813 bus_addr_t lastaddr = 0;
814 struct mbuf *m;
815
816 for (m = m0; m != NULL && error == 0; m = m->m_next) {
817 if (m->m_len > 0) {
818 error = _bus_dmamap_load_buffer(dmat, map,
819 m->m_data, m->m_len,
820 NULL, flags, &lastaddr,
821 segs, nsegs, first);
822 first = 0;
823 }
824 }
825 } else {
826 error = EINVAL;
827 }
828
829 /* XXX FIXME: Having to increment nsegs is really annoying */
830 ++*nsegs;
831 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
832 __func__, dmat, dmat->flags, error, *nsegs);
833 return (error);
834 }
835
836 int
837 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
838 struct mbuf *m0,
839 bus_dmamap_callback2_t *callback, void *callback_arg,
840 int flags)
841 {
842 int nsegs, error;
843
844 error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, dmat->segments, &nsegs,
845 flags);
846
847 if (error) {
848 /* force "no valid mappings" in callback */
849 (*callback)(callback_arg, dmat->segments, 0, 0, error);
850 } else {
851 (*callback)(callback_arg, dmat->segments,
852 nsegs, m0->m_pkthdr.len, error);
853 }
854 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
855 __func__, dmat, dmat->flags, error, nsegs);
856 return (error);
857 }
858
859 int
860 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
861 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
862 int flags)
863 {
864 return (_bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags));
865 }
866
867 /*
868 * Like _bus_dmamap_load(), but for uios.
869 */
870 int
871 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
872 struct uio *uio,
873 bus_dmamap_callback2_t *callback, void *callback_arg,
874 int flags)
875 {
876 bus_addr_t lastaddr;
877 int nsegs, error, first, i;
878 bus_size_t resid;
879 struct iovec *iov;
880 pmap_t pmap;
881
882 flags |= BUS_DMA_NOWAIT;
883 resid = uio->uio_resid;
884 iov = uio->uio_iov;
885
886 if (uio->uio_segflg == UIO_USERSPACE) {
887 KASSERT(uio->uio_td != NULL,
888 ("bus_dmamap_load_uio: USERSPACE but no proc"));
889 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
890 } else
891 pmap = NULL;
892
893 nsegs = 0;
894 error = 0;
895 first = 1;
896 lastaddr = (bus_addr_t) 0;
897 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
898 /*
899 * Now at the first iovec to load. Load each iovec
900 * until we have exhausted the residual count.
901 */
902 bus_size_t minlen =
903 resid < iov[i].iov_len ? resid : iov[i].iov_len;
904 caddr_t addr = (caddr_t) iov[i].iov_base;
905
906 if (minlen > 0) {
907 error = _bus_dmamap_load_buffer(dmat, map,
908 addr, minlen, pmap, flags, &lastaddr,
909 dmat->segments, &nsegs, first);
910 first = 0;
911
912 resid -= minlen;
913 }
914 }
915
916 if (error) {
917 /* force "no valid mappings" in callback */
918 (*callback)(callback_arg, dmat->segments, 0, 0, error);
919 } else {
920 (*callback)(callback_arg, dmat->segments,
921 nsegs+1, uio->uio_resid, error);
922 }
923 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
924 __func__, dmat, dmat->flags, error, nsegs + 1);
925 return (error);
926 }
927
928 /*
929 * Release the mapping held by map.
930 */
931 void
932 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
933 {
934 struct bounce_page *bpage;
935
936 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
937 STAILQ_REMOVE_HEAD(&map->bpages, links);
938 free_bounce_page(dmat, bpage);
939 }
940 }
941
942 void
943 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
944 {
945 struct bounce_page *bpage;
946
947 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
948 /*
949 * Handle data bouncing. We might also
950 * want to add support for invalidating
951 * the caches on broken hardware
952 */
953 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
954 "performing bounce", __func__, op, dmat, dmat->flags);
955
956 if (op & BUS_DMASYNC_PREWRITE) {
957 while (bpage != NULL) {
958 bcopy((void *)bpage->datavaddr,
959 (void *)bpage->vaddr,
960 bpage->datacount);
961 bpage = STAILQ_NEXT(bpage, links);
962 }
963 dmat->bounce_zone->total_bounced++;
964 }
965
966 if (op & BUS_DMASYNC_POSTREAD) {
967 while (bpage != NULL) {
968 bcopy((void *)bpage->vaddr,
969 (void *)bpage->datavaddr,
970 bpage->datacount);
971 bpage = STAILQ_NEXT(bpage, links);
972 }
973 dmat->bounce_zone->total_bounced++;
974 }
975 }
976 }
977
978 static void
979 init_bounce_pages(void *dummy __unused)
980 {
981
982 total_bpages = 0;
983 STAILQ_INIT(&bounce_zone_list);
984 STAILQ_INIT(&bounce_map_waitinglist);
985 STAILQ_INIT(&bounce_map_callbacklist);
986 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
987 }
988 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
989
990 static struct sysctl_ctx_list *
991 busdma_sysctl_tree(struct bounce_zone *bz)
992 {
993 return (&bz->sysctl_tree);
994 }
995
996 static struct sysctl_oid *
997 busdma_sysctl_tree_top(struct bounce_zone *bz)
998 {
999 return (bz->sysctl_tree_top);
1000 }
1001
1002 static int
1003 alloc_bounce_zone(bus_dma_tag_t dmat)
1004 {
1005 struct bounce_zone *bz;
1006
1007 /* Check to see if we already have a suitable zone */
1008 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1009 if ((dmat->alignment <= bz->alignment)
1010 && (dmat->lowaddr >= bz->lowaddr)) {
1011 dmat->bounce_zone = bz;
1012 return (0);
1013 }
1014 }
1015
1016 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1017 M_NOWAIT | M_ZERO)) == NULL)
1018 return (ENOMEM);
1019
1020 STAILQ_INIT(&bz->bounce_page_list);
1021 bz->free_bpages = 0;
1022 bz->reserved_bpages = 0;
1023 bz->active_bpages = 0;
1024 bz->lowaddr = dmat->lowaddr;
1025 bz->alignment = MAX(dmat->alignment, PAGE_SIZE);
1026 bz->map_count = 0;
1027 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1028 busdma_zonecount++;
1029 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1030 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1031 dmat->bounce_zone = bz;
1032
1033 sysctl_ctx_init(&bz->sysctl_tree);
1034 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1035 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1036 CTLFLAG_RD, 0, "");
1037 if (bz->sysctl_tree_top == NULL) {
1038 sysctl_ctx_free(&bz->sysctl_tree);
1039 return (0); /* XXX error code? */
1040 }
1041
1042 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1043 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1044 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1045 "Total bounce pages");
1046 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1047 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1048 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1049 "Free bounce pages");
1050 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1051 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1052 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1053 "Reserved bounce pages");
1054 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1055 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1056 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1057 "Active bounce pages");
1058 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1059 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1060 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1061 "Total bounce requests");
1062 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1063 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1064 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1065 "Total bounce requests that were deferred");
1066 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1067 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1068 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1069 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1070 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1071 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1072
1073 return (0);
1074 }
1075
1076 static int
1077 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1078 {
1079 struct bounce_zone *bz;
1080 int count;
1081
1082 bz = dmat->bounce_zone;
1083 count = 0;
1084 while (numpages > 0) {
1085 struct bounce_page *bpage;
1086
1087 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1088 M_NOWAIT | M_ZERO);
1089
1090 if (bpage == NULL)
1091 break;
1092 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1093 M_NOWAIT, 0ul,
1094 bz->lowaddr,
1095 PAGE_SIZE,
1096 0);
1097 if (bpage->vaddr == 0) {
1098 free(bpage, M_DEVBUF);
1099 break;
1100 }
1101 bpage->busaddr = pmap_kextract(bpage->vaddr);
1102 mtx_lock(&bounce_lock);
1103 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1104 total_bpages++;
1105 bz->total_bpages++;
1106 bz->free_bpages++;
1107 mtx_unlock(&bounce_lock);
1108 count++;
1109 numpages--;
1110 }
1111 return (count);
1112 }
1113
1114 static int
1115 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1116 {
1117 struct bounce_zone *bz;
1118 int pages;
1119
1120 mtx_assert(&bounce_lock, MA_OWNED);
1121 bz = dmat->bounce_zone;
1122 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1123 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1124 return (map->pagesneeded - (map->pagesreserved + pages));
1125 bz->free_bpages -= pages;
1126 bz->reserved_bpages += pages;
1127 map->pagesreserved += pages;
1128 pages = map->pagesneeded - map->pagesreserved;
1129
1130 return (pages);
1131 }
1132
1133 static bus_addr_t
1134 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1135 bus_size_t size)
1136 {
1137 struct bounce_zone *bz;
1138 struct bounce_page *bpage;
1139
1140 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1141 KASSERT(map != NULL && map != &nobounce_dmamap,
1142 ("add_bounce_page: bad map %p", map));
1143
1144 bz = dmat->bounce_zone;
1145 if (map->pagesneeded == 0)
1146 panic("add_bounce_page: map doesn't need any pages");
1147 map->pagesneeded--;
1148
1149 if (map->pagesreserved == 0)
1150 panic("add_bounce_page: map doesn't need any pages");
1151 map->pagesreserved--;
1152
1153 mtx_lock(&bounce_lock);
1154 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1155 if (bpage == NULL)
1156 panic("add_bounce_page: free page list is empty");
1157
1158 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1159 bz->reserved_bpages--;
1160 bz->active_bpages++;
1161 mtx_unlock(&bounce_lock);
1162
1163 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1164 /* Page offset needs to be preserved. */
1165 bpage->vaddr |= vaddr & PAGE_MASK;
1166 bpage->busaddr |= vaddr & PAGE_MASK;
1167 }
1168 bpage->datavaddr = vaddr;
1169 bpage->datacount = size;
1170 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1171 return (bpage->busaddr);
1172 }
1173
1174 static void
1175 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1176 {
1177 struct bus_dmamap *map;
1178 struct bounce_zone *bz;
1179
1180 bz = dmat->bounce_zone;
1181 bpage->datavaddr = 0;
1182 bpage->datacount = 0;
1183 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1184 /*
1185 * Reset the bounce page to start at offset 0. Other uses
1186 * of this bounce page may need to store a full page of
1187 * data and/or assume it starts on a page boundary.
1188 */
1189 bpage->vaddr &= ~PAGE_MASK;
1190 bpage->busaddr &= ~PAGE_MASK;
1191 }
1192
1193 mtx_lock(&bounce_lock);
1194 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1195 bz->free_bpages++;
1196 bz->active_bpages--;
1197 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1198 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1199 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1200 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1201 map, links);
1202 busdma_swi_pending = 1;
1203 bz->total_deferred++;
1204 swi_sched(vm_ih, 0);
1205 }
1206 }
1207 mtx_unlock(&bounce_lock);
1208 }
1209
1210 void
1211 busdma_swi(void)
1212 {
1213 bus_dma_tag_t dmat;
1214 struct bus_dmamap *map;
1215
1216 mtx_lock(&bounce_lock);
1217 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1218 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1219 mtx_unlock(&bounce_lock);
1220 dmat = map->dmat;
1221 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1222 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1223 map->callback, map->callback_arg, /*flags*/0);
1224 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1225 mtx_lock(&bounce_lock);
1226 }
1227 mtx_unlock(&bounce_lock);
1228 }
Cache object: dbc59b5c7b2c85aef3bc7bfa686492d1
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