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/9.1/sys/x86/x86/busdma_machdep.c 232372 2012-03-02 00:21:07Z emaste $");
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 #ifdef __i386__
54 #define MAX_BPAGES 512
55 #else
56 #define MAX_BPAGES 8192
57 #endif
58 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3
59 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
60
61 struct bounce_zone;
62
63 struct bus_dma_tag {
64 bus_dma_tag_t parent;
65 bus_size_t alignment;
66 bus_size_t boundary;
67 bus_addr_t lowaddr;
68 bus_addr_t highaddr;
69 bus_dma_filter_t *filter;
70 void *filterarg;
71 bus_size_t maxsize;
72 u_int nsegments;
73 bus_size_t maxsegsz;
74 int flags;
75 int ref_count;
76 int map_count;
77 bus_dma_lock_t *lockfunc;
78 void *lockfuncarg;
79 bus_dma_segment_t *segments;
80 struct bounce_zone *bounce_zone;
81 };
82
83 struct bounce_page {
84 vm_offset_t vaddr; /* kva of bounce buffer */
85 bus_addr_t busaddr; /* Physical address */
86 vm_offset_t datavaddr; /* kva of client data */
87 bus_size_t datacount; /* client data count */
88 STAILQ_ENTRY(bounce_page) links;
89 };
90
91 int busdma_swi_pending;
92
93 struct bounce_zone {
94 STAILQ_ENTRY(bounce_zone) links;
95 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
96 int total_bpages;
97 int free_bpages;
98 int reserved_bpages;
99 int active_bpages;
100 int total_bounced;
101 int total_deferred;
102 int map_count;
103 bus_size_t alignment;
104 bus_addr_t lowaddr;
105 char zoneid[8];
106 char lowaddrid[20];
107 struct sysctl_ctx_list sysctl_tree;
108 struct sysctl_oid *sysctl_tree_top;
109 };
110
111 static struct mtx bounce_lock;
112 static int total_bpages;
113 static int busdma_zonecount;
114 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
115
116 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
117 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
118 "Total bounce pages");
119
120 struct bus_dmamap {
121 struct bp_list bpages;
122 int pagesneeded;
123 int pagesreserved;
124 bus_dma_tag_t dmat;
125 void *buf; /* unmapped buffer pointer */
126 bus_size_t buflen; /* unmapped buffer length */
127 bus_dmamap_callback_t *callback;
128 void *callback_arg;
129 STAILQ_ENTRY(bus_dmamap) links;
130 };
131
132 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
133 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
134 static struct bus_dmamap nobounce_dmamap;
135
136 static void init_bounce_pages(void *dummy);
137 static int alloc_bounce_zone(bus_dma_tag_t dmat);
138 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
139 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
140 int commit);
141 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
142 vm_offset_t vaddr, bus_size_t size);
143 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
144 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
145 int _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
146 void *buf, bus_size_t buflen, int flags);
147
148 #ifdef XEN
149 #undef pmap_kextract
150 #define pmap_kextract pmap_kextract_ma
151 #endif
152
153 /*
154 * Return true if a match is made.
155 *
156 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
157 *
158 * If paddr is within the bounds of the dma tag then call the filter callback
159 * to check for a match, if there is no filter callback then assume a match.
160 */
161 int
162 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
163 {
164 int retval;
165
166 retval = 0;
167
168 do {
169 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
170 || ((paddr & (dmat->alignment - 1)) != 0))
171 && (dmat->filter == NULL
172 || (*dmat->filter)(dmat->filterarg, paddr) != 0))
173 retval = 1;
174
175 dmat = dmat->parent;
176 } while (retval == 0 && dmat != NULL);
177 return (retval);
178 }
179
180 /*
181 * Convenience function for manipulating driver locks from busdma (during
182 * busdma_swi, for example). Drivers that don't provide their own locks
183 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own
184 * non-mutex locking scheme don't have to use this at all.
185 */
186 void
187 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
188 {
189 struct mtx *dmtx;
190
191 dmtx = (struct mtx *)arg;
192 switch (op) {
193 case BUS_DMA_LOCK:
194 mtx_lock(dmtx);
195 break;
196 case BUS_DMA_UNLOCK:
197 mtx_unlock(dmtx);
198 break;
199 default:
200 panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
201 }
202 }
203
204 /*
205 * dflt_lock should never get called. It gets put into the dma tag when
206 * lockfunc == NULL, which is only valid if the maps that are associated
207 * with the tag are meant to never be defered.
208 * XXX Should have a way to identify which driver is responsible here.
209 */
210 static void
211 dflt_lock(void *arg, bus_dma_lock_op_t op)
212 {
213 panic("driver error: busdma dflt_lock called");
214 }
215
216 /*
217 * Allocate a device specific dma_tag.
218 */
219 int
220 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
221 bus_size_t boundary, bus_addr_t lowaddr,
222 bus_addr_t highaddr, bus_dma_filter_t *filter,
223 void *filterarg, bus_size_t maxsize, int nsegments,
224 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
225 void *lockfuncarg, bus_dma_tag_t *dmat)
226 {
227 bus_dma_tag_t newtag;
228 int error = 0;
229
230 /* Always enforce at least a 4GB (2GB for PAE) boundary. */
231 #if defined(__amd64__)
232 if (boundary == 0 || boundary > ((bus_addr_t)1 << 32))
233 boundary = (bus_size_t)1 << 32;
234 #elif defined(PAE)
235 if (boundary == 0 || boundary > ((bus_addr_t)1 << 31))
236 boundary = (bus_size_t)1 << 31;
237 #endif
238 /* Basic sanity checking */
239 if (boundary != 0 && boundary < maxsegsz)
240 maxsegsz = boundary;
241
242 if (maxsegsz == 0) {
243 return (EINVAL);
244 }
245
246 /* Return a NULL tag on failure */
247 *dmat = NULL;
248
249 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF,
250 M_ZERO | M_NOWAIT);
251 if (newtag == NULL) {
252 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
253 __func__, newtag, 0, error);
254 return (ENOMEM);
255 }
256
257 newtag->parent = parent;
258 newtag->alignment = alignment;
259 newtag->boundary = boundary;
260 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
261 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
262 newtag->filter = filter;
263 newtag->filterarg = filterarg;
264 newtag->maxsize = maxsize;
265 newtag->nsegments = nsegments;
266 newtag->maxsegsz = maxsegsz;
267 newtag->flags = flags;
268 newtag->ref_count = 1; /* Count ourself */
269 newtag->map_count = 0;
270 if (lockfunc != NULL) {
271 newtag->lockfunc = lockfunc;
272 newtag->lockfuncarg = lockfuncarg;
273 } else {
274 newtag->lockfunc = dflt_lock;
275 newtag->lockfuncarg = NULL;
276 }
277 newtag->segments = NULL;
278
279 /* Take into account any restrictions imposed by our parent tag */
280 if (parent != NULL) {
281 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
282 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
283 if (newtag->boundary == 0)
284 newtag->boundary = parent->boundary;
285 else if (parent->boundary != 0)
286 newtag->boundary = MIN(parent->boundary,
287 newtag->boundary);
288 if ((newtag->filter != NULL) ||
289 ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
290 newtag->flags |= BUS_DMA_COULD_BOUNCE;
291 if (newtag->filter == NULL) {
292 /*
293 * Short circuit looking at our parent directly
294 * since we have encapsulated all of its information
295 */
296 newtag->filter = parent->filter;
297 newtag->filterarg = parent->filterarg;
298 newtag->parent = parent->parent;
299 }
300 if (newtag->parent != NULL)
301 atomic_add_int(&parent->ref_count, 1);
302 }
303
304 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem)
305 || newtag->alignment > 1)
306 newtag->flags |= BUS_DMA_COULD_BOUNCE;
307
308 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
309 (flags & BUS_DMA_ALLOCNOW) != 0) {
310 struct bounce_zone *bz;
311
312 /* Must bounce */
313
314 if ((error = alloc_bounce_zone(newtag)) != 0) {
315 free(newtag, M_DEVBUF);
316 return (error);
317 }
318 bz = newtag->bounce_zone;
319
320 if (ptoa(bz->total_bpages) < maxsize) {
321 int pages;
322
323 pages = atop(maxsize) - bz->total_bpages;
324
325 /* Add pages to our bounce pool */
326 if (alloc_bounce_pages(newtag, pages) < pages)
327 error = ENOMEM;
328 }
329 /* Performed initial allocation */
330 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
331 }
332
333 if (error != 0) {
334 free(newtag, M_DEVBUF);
335 } else {
336 *dmat = newtag;
337 }
338 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
339 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
340 return (error);
341 }
342
343 int
344 bus_dma_tag_destroy(bus_dma_tag_t dmat)
345 {
346 bus_dma_tag_t dmat_copy;
347 int error;
348
349 error = 0;
350 dmat_copy = dmat;
351
352 if (dmat != NULL) {
353
354 if (dmat->map_count != 0) {
355 error = EBUSY;
356 goto out;
357 }
358
359 while (dmat != NULL) {
360 bus_dma_tag_t parent;
361
362 parent = dmat->parent;
363 atomic_subtract_int(&dmat->ref_count, 1);
364 if (dmat->ref_count == 0) {
365 if (dmat->segments != NULL)
366 free(dmat->segments, M_DEVBUF);
367 free(dmat, M_DEVBUF);
368 /*
369 * Last reference count, so
370 * release our reference
371 * count on our parent.
372 */
373 dmat = parent;
374 } else
375 dmat = NULL;
376 }
377 }
378 out:
379 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
380 return (error);
381 }
382
383 /*
384 * Allocate a handle for mapping from kva/uva/physical
385 * address space into bus device space.
386 */
387 int
388 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
389 {
390 int error;
391
392 error = 0;
393
394 if (dmat->segments == NULL) {
395 dmat->segments = (bus_dma_segment_t *)malloc(
396 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
397 M_NOWAIT);
398 if (dmat->segments == NULL) {
399 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
400 __func__, dmat, ENOMEM);
401 return (ENOMEM);
402 }
403 }
404
405 /*
406 * Bouncing might be required if the driver asks for an active
407 * exclusion region, a data alignment that is stricter than 1, and/or
408 * an active address boundary.
409 */
410 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
411
412 /* Must bounce */
413 struct bounce_zone *bz;
414 int maxpages;
415
416 if (dmat->bounce_zone == NULL) {
417 if ((error = alloc_bounce_zone(dmat)) != 0)
418 return (error);
419 }
420 bz = dmat->bounce_zone;
421
422 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
423 M_NOWAIT | M_ZERO);
424 if (*mapp == NULL) {
425 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
426 __func__, dmat, ENOMEM);
427 return (ENOMEM);
428 }
429
430 /* Initialize the new map */
431 STAILQ_INIT(&((*mapp)->bpages));
432
433 /*
434 * Attempt to add pages to our pool on a per-instance
435 * basis up to a sane limit.
436 */
437 if (dmat->alignment > 1)
438 maxpages = MAX_BPAGES;
439 else
440 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr));
441 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
442 || (bz->map_count > 0 && bz->total_bpages < maxpages)) {
443 int pages;
444
445 pages = MAX(atop(dmat->maxsize), 1);
446 pages = MIN(maxpages - bz->total_bpages, pages);
447 pages = MAX(pages, 1);
448 if (alloc_bounce_pages(dmat, pages) < pages)
449 error = ENOMEM;
450
451 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
452 if (error == 0)
453 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
454 } else {
455 error = 0;
456 }
457 }
458 bz->map_count++;
459 } else {
460 *mapp = NULL;
461 }
462 if (error == 0)
463 dmat->map_count++;
464 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
465 __func__, dmat, dmat->flags, error);
466 return (error);
467 }
468
469 /*
470 * Destroy a handle for mapping from kva/uva/physical
471 * address space into bus device space.
472 */
473 int
474 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
475 {
476 if (map != NULL && map != &nobounce_dmamap) {
477 if (STAILQ_FIRST(&map->bpages) != NULL) {
478 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
479 __func__, dmat, EBUSY);
480 return (EBUSY);
481 }
482 if (dmat->bounce_zone)
483 dmat->bounce_zone->map_count--;
484 free(map, M_DEVBUF);
485 }
486 dmat->map_count--;
487 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
488 return (0);
489 }
490
491
492 /*
493 * Allocate a piece of memory that can be efficiently mapped into
494 * bus device space based on the constraints lited in the dma tag.
495 * A dmamap to for use with dmamap_load is also allocated.
496 */
497 int
498 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
499 bus_dmamap_t *mapp)
500 {
501 int mflags;
502
503 if (flags & BUS_DMA_NOWAIT)
504 mflags = M_NOWAIT;
505 else
506 mflags = M_WAITOK;
507
508 /* If we succeed, no mapping/bouncing will be required */
509 *mapp = NULL;
510
511 if (dmat->segments == NULL) {
512 dmat->segments = (bus_dma_segment_t *)malloc(
513 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
514 mflags);
515 if (dmat->segments == NULL) {
516 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
517 __func__, dmat, dmat->flags, ENOMEM);
518 return (ENOMEM);
519 }
520 }
521 if (flags & BUS_DMA_ZERO)
522 mflags |= M_ZERO;
523
524 /*
525 * XXX:
526 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
527 * alignment guarantees of malloc need to be nailed down, and the
528 * code below should be rewritten to take that into account.
529 *
530 * In the meantime, we'll warn the user if malloc gets it wrong.
531 */
532 if ((dmat->maxsize <= PAGE_SIZE) &&
533 (dmat->alignment < dmat->maxsize) &&
534 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
535 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
536 } else {
537 /*
538 * XXX Use Contigmalloc until it is merged into this facility
539 * and handles multi-seg allocations. Nobody is doing
540 * multi-seg allocations yet though.
541 * XXX Certain AGP hardware does.
542 */
543 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
544 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
545 dmat->boundary);
546 }
547 if (*vaddr == NULL) {
548 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
549 __func__, dmat, dmat->flags, ENOMEM);
550 return (ENOMEM);
551 } else if (vtophys(*vaddr) & (dmat->alignment - 1)) {
552 printf("bus_dmamem_alloc failed to align memory properly.\n");
553 }
554 if (flags & BUS_DMA_NOCACHE)
555 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize,
556 PAT_UNCACHEABLE);
557 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
558 __func__, dmat, dmat->flags, 0);
559 return (0);
560 }
561
562 /*
563 * Free a piece of memory and it's allociated dmamap, that was allocated
564 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
565 */
566 void
567 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
568 {
569 /*
570 * dmamem does not need to be bounced, so the map should be
571 * NULL
572 */
573 if (map != NULL)
574 panic("bus_dmamem_free: Invalid map freed\n");
575 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK);
576 if ((dmat->maxsize <= PAGE_SIZE) &&
577 (dmat->alignment < dmat->maxsize) &&
578 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
579 free(vaddr, M_DEVBUF);
580 else {
581 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
582 }
583 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
584 }
585
586 int
587 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
588 void *buf, bus_size_t buflen, int flags)
589 {
590 vm_offset_t vaddr;
591 vm_offset_t vendaddr;
592 bus_addr_t paddr;
593
594 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
595 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
596 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
597 dmat->boundary, dmat->alignment);
598 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
599 map, &nobounce_dmamap, map->pagesneeded);
600 /*
601 * Count the number of bounce pages
602 * needed in order to complete this transfer
603 */
604 vaddr = (vm_offset_t)buf;
605 vendaddr = (vm_offset_t)buf + buflen;
606
607 while (vaddr < vendaddr) {
608 bus_size_t sg_len;
609
610 sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
611 if (pmap)
612 paddr = pmap_extract(pmap, vaddr);
613 else
614 paddr = pmap_kextract(vaddr);
615 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
616 run_filter(dmat, paddr) != 0) {
617 sg_len = roundup2(sg_len, dmat->alignment);
618 map->pagesneeded++;
619 }
620 vaddr += sg_len;
621 }
622 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
623 }
624
625 /* Reserve Necessary Bounce Pages */
626 if (map->pagesneeded != 0) {
627 mtx_lock(&bounce_lock);
628 if (flags & BUS_DMA_NOWAIT) {
629 if (reserve_bounce_pages(dmat, map, 0) != 0) {
630 mtx_unlock(&bounce_lock);
631 return (ENOMEM);
632 }
633 } else {
634 if (reserve_bounce_pages(dmat, map, 1) != 0) {
635 /* Queue us for resources */
636 map->dmat = dmat;
637 map->buf = buf;
638 map->buflen = buflen;
639 STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
640 map, links);
641 mtx_unlock(&bounce_lock);
642 return (EINPROGRESS);
643 }
644 }
645 mtx_unlock(&bounce_lock);
646 }
647
648 return (0);
649 }
650
651 /*
652 * Utility function to load a linear buffer. lastaddrp holds state
653 * between invocations (for multiple-buffer loads). segp contains
654 * the starting segment on entrace, and the ending segment on exit.
655 * first indicates if this is the first invocation of this function.
656 */
657 static __inline int
658 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
659 bus_dmamap_t map,
660 void *buf, bus_size_t buflen,
661 pmap_t pmap,
662 int flags,
663 bus_addr_t *lastaddrp,
664 bus_dma_segment_t *segs,
665 int *segp,
666 int first)
667 {
668 bus_size_t sgsize;
669 bus_addr_t curaddr, lastaddr, baddr, bmask;
670 vm_offset_t vaddr;
671 int seg, error;
672
673 if (map == NULL)
674 map = &nobounce_dmamap;
675
676 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
677 error = _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
678 if (error)
679 return (error);
680 }
681
682 vaddr = (vm_offset_t)buf;
683 lastaddr = *lastaddrp;
684 bmask = ~(dmat->boundary - 1);
685
686 for (seg = *segp; buflen > 0 ; ) {
687 bus_size_t max_sgsize;
688
689 /*
690 * Get the physical address for this segment.
691 */
692 if (pmap)
693 curaddr = pmap_extract(pmap, vaddr);
694 else
695 curaddr = pmap_kextract(vaddr);
696
697 /*
698 * Compute the segment size, and adjust counts.
699 */
700 max_sgsize = MIN(buflen, dmat->maxsegsz);
701 sgsize = PAGE_SIZE - ((vm_offset_t)curaddr & PAGE_MASK);
702 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
703 map->pagesneeded != 0 && run_filter(dmat, curaddr)) {
704 sgsize = roundup2(sgsize, dmat->alignment);
705 sgsize = MIN(sgsize, max_sgsize);
706 curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
707 } else {
708 sgsize = MIN(sgsize, max_sgsize);
709 }
710
711 /*
712 * Make sure we don't cross any boundaries.
713 */
714 if (dmat->boundary > 0) {
715 baddr = (curaddr + dmat->boundary) & bmask;
716 if (sgsize > (baddr - curaddr))
717 sgsize = (baddr - curaddr);
718 }
719
720 /*
721 * Insert chunk into a segment, coalescing with
722 * previous segment if possible.
723 */
724 if (first) {
725 segs[seg].ds_addr = curaddr;
726 segs[seg].ds_len = sgsize;
727 first = 0;
728 } else {
729 if (curaddr == lastaddr &&
730 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
731 (dmat->boundary == 0 ||
732 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
733 segs[seg].ds_len += sgsize;
734 else {
735 if (++seg >= dmat->nsegments)
736 break;
737 segs[seg].ds_addr = curaddr;
738 segs[seg].ds_len = sgsize;
739 }
740 }
741
742 lastaddr = curaddr + sgsize;
743 vaddr += sgsize;
744 buflen -= sgsize;
745 }
746
747 *segp = seg;
748 *lastaddrp = lastaddr;
749
750 /*
751 * Did we fit?
752 */
753 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
754 }
755
756 /*
757 * Map the buffer buf into bus space using the dmamap map.
758 */
759 int
760 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
761 bus_size_t buflen, bus_dmamap_callback_t *callback,
762 void *callback_arg, int flags)
763 {
764 bus_addr_t lastaddr = 0;
765 int error, nsegs = 0;
766
767 if (map != NULL) {
768 flags |= BUS_DMA_WAITOK;
769 map->callback = callback;
770 map->callback_arg = callback_arg;
771 }
772
773 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
774 &lastaddr, dmat->segments, &nsegs, 1);
775
776 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
777 __func__, dmat, dmat->flags, error, nsegs + 1);
778
779 if (error == EINPROGRESS) {
780 return (error);
781 }
782
783 if (error)
784 (*callback)(callback_arg, dmat->segments, 0, error);
785 else
786 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
787
788 /*
789 * Return ENOMEM to the caller so that it can pass it up the stack.
790 * This error only happens when NOWAIT is set, so deferal is disabled.
791 */
792 if (error == ENOMEM)
793 return (error);
794
795 return (0);
796 }
797
798
799 /*
800 * Like _bus_dmamap_load(), but for mbufs.
801 */
802 static __inline int
803 _bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
804 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
805 int flags)
806 {
807 int error;
808
809 M_ASSERTPKTHDR(m0);
810
811 flags |= BUS_DMA_NOWAIT;
812 *nsegs = 0;
813 error = 0;
814 if (m0->m_pkthdr.len <= dmat->maxsize) {
815 int first = 1;
816 bus_addr_t lastaddr = 0;
817 struct mbuf *m;
818
819 for (m = m0; m != NULL && error == 0; m = m->m_next) {
820 if (m->m_len > 0) {
821 error = _bus_dmamap_load_buffer(dmat, map,
822 m->m_data, m->m_len,
823 NULL, flags, &lastaddr,
824 segs, nsegs, first);
825 first = 0;
826 }
827 }
828 } else {
829 error = EINVAL;
830 }
831
832 /* XXX FIXME: Having to increment nsegs is really annoying */
833 ++*nsegs;
834 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
835 __func__, dmat, dmat->flags, error, *nsegs);
836 return (error);
837 }
838
839 int
840 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
841 struct mbuf *m0,
842 bus_dmamap_callback2_t *callback, void *callback_arg,
843 int flags)
844 {
845 int nsegs, error;
846
847 error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, dmat->segments, &nsegs,
848 flags);
849
850 if (error) {
851 /* force "no valid mappings" in callback */
852 (*callback)(callback_arg, dmat->segments, 0, 0, error);
853 } else {
854 (*callback)(callback_arg, dmat->segments,
855 nsegs, m0->m_pkthdr.len, error);
856 }
857 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
858 __func__, dmat, dmat->flags, error, nsegs);
859 return (error);
860 }
861
862 int
863 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
864 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
865 int flags)
866 {
867 return (_bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags));
868 }
869
870 /*
871 * Like _bus_dmamap_load(), but for uios.
872 */
873 int
874 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
875 struct uio *uio,
876 bus_dmamap_callback2_t *callback, void *callback_arg,
877 int flags)
878 {
879 bus_addr_t lastaddr = 0;
880 int nsegs, error, first, i;
881 bus_size_t resid;
882 struct iovec *iov;
883 pmap_t pmap;
884
885 flags |= BUS_DMA_NOWAIT;
886 resid = uio->uio_resid;
887 iov = uio->uio_iov;
888
889 if (uio->uio_segflg == UIO_USERSPACE) {
890 KASSERT(uio->uio_td != NULL,
891 ("bus_dmamap_load_uio: USERSPACE but no proc"));
892 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
893 } else
894 pmap = NULL;
895
896 nsegs = 0;
897 error = 0;
898 first = 1;
899 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
900 /*
901 * Now at the first iovec to load. Load each iovec
902 * until we have exhausted the residual count.
903 */
904 bus_size_t minlen =
905 resid < iov[i].iov_len ? resid : iov[i].iov_len;
906 caddr_t addr = (caddr_t) iov[i].iov_base;
907
908 if (minlen > 0) {
909 error = _bus_dmamap_load_buffer(dmat, map,
910 addr, minlen, pmap, flags, &lastaddr,
911 dmat->segments, &nsegs, first);
912 first = 0;
913
914 resid -= minlen;
915 }
916 }
917
918 if (error) {
919 /* force "no valid mappings" in callback */
920 (*callback)(callback_arg, dmat->segments, 0, 0, error);
921 } else {
922 (*callback)(callback_arg, dmat->segments,
923 nsegs+1, uio->uio_resid, error);
924 }
925 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
926 __func__, dmat, dmat->flags, error, nsegs + 1);
927 return (error);
928 }
929
930 /*
931 * Release the mapping held by map.
932 */
933 void
934 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
935 {
936 struct bounce_page *bpage;
937
938 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
939 STAILQ_REMOVE_HEAD(&map->bpages, links);
940 free_bounce_page(dmat, bpage);
941 }
942 }
943
944 void
945 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
946 {
947 struct bounce_page *bpage;
948
949 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
950 /*
951 * Handle data bouncing. We might also
952 * want to add support for invalidating
953 * the caches on broken hardware
954 */
955 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
956 "performing bounce", __func__, op, dmat, dmat->flags);
957
958 if (op & BUS_DMASYNC_PREWRITE) {
959 while (bpage != NULL) {
960 bcopy((void *)bpage->datavaddr,
961 (void *)bpage->vaddr,
962 bpage->datacount);
963 bpage = STAILQ_NEXT(bpage, links);
964 }
965 dmat->bounce_zone->total_bounced++;
966 }
967
968 if (op & BUS_DMASYNC_POSTREAD) {
969 while (bpage != NULL) {
970 bcopy((void *)bpage->vaddr,
971 (void *)bpage->datavaddr,
972 bpage->datacount);
973 bpage = STAILQ_NEXT(bpage, links);
974 }
975 dmat->bounce_zone->total_bounced++;
976 }
977 }
978 }
979
980 static void
981 init_bounce_pages(void *dummy __unused)
982 {
983
984 total_bpages = 0;
985 STAILQ_INIT(&bounce_zone_list);
986 STAILQ_INIT(&bounce_map_waitinglist);
987 STAILQ_INIT(&bounce_map_callbacklist);
988 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
989 }
990 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
991
992 static struct sysctl_ctx_list *
993 busdma_sysctl_tree(struct bounce_zone *bz)
994 {
995 return (&bz->sysctl_tree);
996 }
997
998 static struct sysctl_oid *
999 busdma_sysctl_tree_top(struct bounce_zone *bz)
1000 {
1001 return (bz->sysctl_tree_top);
1002 }
1003
1004 #if defined(__amd64__) || defined(PAE)
1005 #define SYSCTL_ADD_BUS_SIZE_T SYSCTL_ADD_UQUAD
1006 #else
1007 #define SYSCTL_ADD_BUS_SIZE_T(ctx, parent, nbr, name, flag, ptr, desc) \
1008 SYSCTL_ADD_UINT(ctx, parent, nbr, name, flag, ptr, 0, desc)
1009 #endif
1010
1011 static int
1012 alloc_bounce_zone(bus_dma_tag_t dmat)
1013 {
1014 struct bounce_zone *bz;
1015
1016 /* Check to see if we already have a suitable zone */
1017 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1018 if ((dmat->alignment <= bz->alignment)
1019 && (dmat->lowaddr >= bz->lowaddr)) {
1020 dmat->bounce_zone = bz;
1021 return (0);
1022 }
1023 }
1024
1025 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1026 M_NOWAIT | M_ZERO)) == NULL)
1027 return (ENOMEM);
1028
1029 STAILQ_INIT(&bz->bounce_page_list);
1030 bz->free_bpages = 0;
1031 bz->reserved_bpages = 0;
1032 bz->active_bpages = 0;
1033 bz->lowaddr = dmat->lowaddr;
1034 bz->alignment = MAX(dmat->alignment, PAGE_SIZE);
1035 bz->map_count = 0;
1036 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1037 busdma_zonecount++;
1038 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1039 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1040 dmat->bounce_zone = bz;
1041
1042 sysctl_ctx_init(&bz->sysctl_tree);
1043 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1044 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1045 CTLFLAG_RD, 0, "");
1046 if (bz->sysctl_tree_top == NULL) {
1047 sysctl_ctx_free(&bz->sysctl_tree);
1048 return (0); /* XXX error code? */
1049 }
1050
1051 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1052 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1053 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1054 "Total bounce pages");
1055 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1056 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1057 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1058 "Free bounce pages");
1059 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1060 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1061 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1062 "Reserved bounce pages");
1063 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1064 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1065 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1066 "Active bounce pages");
1067 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1068 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1069 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1070 "Total bounce requests");
1071 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1072 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1073 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1074 "Total bounce requests that were deferred");
1075 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1076 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1077 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1078 SYSCTL_ADD_BUS_SIZE_T(busdma_sysctl_tree(bz),
1079 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1080 "alignment", CTLFLAG_RD, &bz->alignment, "");
1081
1082 return (0);
1083 }
1084
1085 static int
1086 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1087 {
1088 struct bounce_zone *bz;
1089 int count;
1090
1091 bz = dmat->bounce_zone;
1092 count = 0;
1093 while (numpages > 0) {
1094 struct bounce_page *bpage;
1095
1096 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1097 M_NOWAIT | M_ZERO);
1098
1099 if (bpage == NULL)
1100 break;
1101 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1102 M_NOWAIT, 0ul,
1103 bz->lowaddr,
1104 PAGE_SIZE,
1105 0);
1106 if (bpage->vaddr == 0) {
1107 free(bpage, M_DEVBUF);
1108 break;
1109 }
1110 bpage->busaddr = pmap_kextract(bpage->vaddr);
1111 mtx_lock(&bounce_lock);
1112 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1113 total_bpages++;
1114 bz->total_bpages++;
1115 bz->free_bpages++;
1116 mtx_unlock(&bounce_lock);
1117 count++;
1118 numpages--;
1119 }
1120 return (count);
1121 }
1122
1123 static int
1124 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1125 {
1126 struct bounce_zone *bz;
1127 int pages;
1128
1129 mtx_assert(&bounce_lock, MA_OWNED);
1130 bz = dmat->bounce_zone;
1131 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1132 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1133 return (map->pagesneeded - (map->pagesreserved + pages));
1134 bz->free_bpages -= pages;
1135 bz->reserved_bpages += pages;
1136 map->pagesreserved += pages;
1137 pages = map->pagesneeded - map->pagesreserved;
1138
1139 return (pages);
1140 }
1141
1142 static bus_addr_t
1143 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1144 bus_size_t size)
1145 {
1146 struct bounce_zone *bz;
1147 struct bounce_page *bpage;
1148
1149 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1150 KASSERT(map != NULL && map != &nobounce_dmamap,
1151 ("add_bounce_page: bad map %p", map));
1152
1153 bz = dmat->bounce_zone;
1154 if (map->pagesneeded == 0)
1155 panic("add_bounce_page: map doesn't need any pages");
1156 map->pagesneeded--;
1157
1158 if (map->pagesreserved == 0)
1159 panic("add_bounce_page: map doesn't need any pages");
1160 map->pagesreserved--;
1161
1162 mtx_lock(&bounce_lock);
1163 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1164 if (bpage == NULL)
1165 panic("add_bounce_page: free page list is empty");
1166
1167 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1168 bz->reserved_bpages--;
1169 bz->active_bpages++;
1170 mtx_unlock(&bounce_lock);
1171
1172 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1173 /* Page offset needs to be preserved. */
1174 bpage->vaddr |= vaddr & PAGE_MASK;
1175 bpage->busaddr |= vaddr & PAGE_MASK;
1176 }
1177 bpage->datavaddr = vaddr;
1178 bpage->datacount = size;
1179 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1180 return (bpage->busaddr);
1181 }
1182
1183 static void
1184 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1185 {
1186 struct bus_dmamap *map;
1187 struct bounce_zone *bz;
1188
1189 bz = dmat->bounce_zone;
1190 bpage->datavaddr = 0;
1191 bpage->datacount = 0;
1192 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1193 /*
1194 * Reset the bounce page to start at offset 0. Other uses
1195 * of this bounce page may need to store a full page of
1196 * data and/or assume it starts on a page boundary.
1197 */
1198 bpage->vaddr &= ~PAGE_MASK;
1199 bpage->busaddr &= ~PAGE_MASK;
1200 }
1201
1202 mtx_lock(&bounce_lock);
1203 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1204 bz->free_bpages++;
1205 bz->active_bpages--;
1206 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1207 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1208 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1209 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1210 map, links);
1211 busdma_swi_pending = 1;
1212 bz->total_deferred++;
1213 swi_sched(vm_ih, 0);
1214 }
1215 }
1216 mtx_unlock(&bounce_lock);
1217 }
1218
1219 void
1220 busdma_swi(void)
1221 {
1222 bus_dma_tag_t dmat;
1223 struct bus_dmamap *map;
1224
1225 mtx_lock(&bounce_lock);
1226 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1227 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1228 mtx_unlock(&bounce_lock);
1229 dmat = map->dmat;
1230 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1231 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1232 map->callback, map->callback_arg, /*flags*/0);
1233 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1234 mtx_lock(&bounce_lock);
1235 }
1236 mtx_unlock(&bounce_lock);
1237 }
Cache object: 7fdae8a7cddb77f1524cc92150e0beaa
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