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/6.2/sys/i386/i386/busdma_machdep.c 163579 2006-10-21 16:26:53Z hrs $");
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
55 #define MAX_BPAGES 512
56
57 struct bounce_zone;
58
59 struct bus_dma_tag {
60 bus_dma_tag_t parent;
61 bus_size_t alignment;
62 bus_size_t boundary;
63 bus_addr_t lowaddr;
64 bus_addr_t highaddr;
65 bus_dma_filter_t *filter;
66 void *filterarg;
67 bus_size_t maxsize;
68 u_int nsegments;
69 bus_size_t maxsegsz;
70 int flags;
71 int ref_count;
72 int map_count;
73 bus_dma_lock_t *lockfunc;
74 void *lockfuncarg;
75 bus_dma_segment_t *segments;
76 struct bounce_zone *bounce_zone;
77 };
78
79 struct bounce_page {
80 vm_offset_t vaddr; /* kva of bounce buffer */
81 bus_addr_t busaddr; /* Physical address */
82 vm_offset_t datavaddr; /* kva of client data */
83 bus_size_t datacount; /* client data count */
84 STAILQ_ENTRY(bounce_page) links;
85 };
86
87 int busdma_swi_pending;
88
89 struct bounce_zone {
90 STAILQ_ENTRY(bounce_zone) links;
91 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
92 int total_bpages;
93 int free_bpages;
94 int reserved_bpages;
95 int active_bpages;
96 int total_bounced;
97 int total_deferred;
98 bus_size_t alignment;
99 bus_size_t boundary;
100 bus_addr_t lowaddr;
101 char zoneid[8];
102 char lowaddrid[20];
103 struct sysctl_ctx_list sysctl_tree;
104 struct sysctl_oid *sysctl_tree_top;
105 };
106
107 static struct mtx bounce_lock;
108 static int total_bpages;
109 static int busdma_zonecount;
110 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
111
112 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
113 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
114 "Total bounce pages");
115
116 struct bus_dmamap {
117 struct bp_list bpages;
118 int pagesneeded;
119 int pagesreserved;
120 bus_dma_tag_t dmat;
121 void *buf; /* unmapped buffer pointer */
122 bus_size_t buflen; /* unmapped buffer length */
123 bus_dmamap_callback_t *callback;
124 void *callback_arg;
125 STAILQ_ENTRY(bus_dmamap) links;
126 };
127
128 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
129 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
130 static struct bus_dmamap nobounce_dmamap;
131
132 static void init_bounce_pages(void *dummy);
133 static int alloc_bounce_zone(bus_dma_tag_t dmat);
134 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
135 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
136 int commit);
137 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
138 vm_offset_t vaddr, bus_size_t size);
139 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
140 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
141
142 /*
143 * Return true if a match is made.
144 *
145 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
146 *
147 * If paddr is within the bounds of the dma tag then call the filter callback
148 * to check for a match, if there is no filter callback then assume a match.
149 */
150 static __inline int
151 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
152 {
153 int retval;
154
155 retval = 0;
156
157 do {
158 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
159 || ((paddr & (dmat->alignment - 1)) != 0))
160 && (dmat->filter == NULL
161 || (*dmat->filter)(dmat->filterarg, paddr) != 0))
162 retval = 1;
163
164 dmat = dmat->parent;
165 } while (retval == 0 && dmat != NULL);
166 return (retval);
167 }
168
169 /*
170 * Convenience function for manipulating driver locks from busdma (during
171 * busdma_swi, for example). Drivers that don't provide their own locks
172 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own
173 * non-mutex locking scheme don't have to use this at all.
174 */
175 void
176 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
177 {
178 struct mtx *dmtx;
179
180 dmtx = (struct mtx *)arg;
181 switch (op) {
182 case BUS_DMA_LOCK:
183 mtx_lock(dmtx);
184 break;
185 case BUS_DMA_UNLOCK:
186 mtx_unlock(dmtx);
187 break;
188 default:
189 panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
190 }
191 }
192
193 /*
194 * dflt_lock should never get called. It gets put into the dma tag when
195 * lockfunc == NULL, which is only valid if the maps that are associated
196 * with the tag are meant to never be defered.
197 * XXX Should have a way to identify which driver is responsible here.
198 */
199 static void
200 dflt_lock(void *arg, bus_dma_lock_op_t op)
201 {
202 panic("driver error: busdma dflt_lock called");
203 }
204
205 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3
206 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
207 /*
208 * Allocate a device specific dma_tag.
209 */
210 int
211 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
212 bus_size_t boundary, bus_addr_t lowaddr,
213 bus_addr_t highaddr, bus_dma_filter_t *filter,
214 void *filterarg, bus_size_t maxsize, int nsegments,
215 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
216 void *lockfuncarg, bus_dma_tag_t *dmat)
217 {
218 bus_dma_tag_t newtag;
219 int error = 0;
220
221 /* Basic sanity checking */
222 if (boundary != 0 && boundary < maxsegsz)
223 maxsegsz = boundary;
224
225 /* Return a NULL tag on failure */
226 *dmat = NULL;
227
228 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF,
229 M_ZERO | M_NOWAIT);
230 if (newtag == NULL) {
231 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
232 __func__, newtag, 0, error);
233 return (ENOMEM);
234 }
235
236 newtag->parent = parent;
237 newtag->alignment = alignment;
238 newtag->boundary = boundary;
239 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
240 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) +
241 (PAGE_SIZE - 1);
242 newtag->filter = filter;
243 newtag->filterarg = filterarg;
244 newtag->maxsize = maxsize;
245 newtag->nsegments = nsegments;
246 newtag->maxsegsz = maxsegsz;
247 newtag->flags = flags;
248 newtag->ref_count = 1; /* Count ourself */
249 newtag->map_count = 0;
250 if (lockfunc != NULL) {
251 newtag->lockfunc = lockfunc;
252 newtag->lockfuncarg = lockfuncarg;
253 } else {
254 newtag->lockfunc = dflt_lock;
255 newtag->lockfuncarg = NULL;
256 }
257 newtag->segments = NULL;
258
259 /* Take into account any restrictions imposed by our parent tag */
260 if (parent != NULL) {
261 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
262 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
263 if (newtag->boundary == 0)
264 newtag->boundary = parent->boundary;
265 else if (parent->boundary != 0)
266 newtag->boundary = MIN(parent->boundary,
267 newtag->boundary);
268 if (newtag->filter == NULL) {
269 /*
270 * Short circuit looking at our parent directly
271 * since we have encapsulated all of its information
272 */
273 newtag->filter = parent->filter;
274 newtag->filterarg = parent->filterarg;
275 newtag->parent = parent->parent;
276 }
277 if (newtag->parent != NULL)
278 atomic_add_int(&parent->ref_count, 1);
279 }
280
281 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem)
282 || newtag->alignment > 1)
283 newtag->flags |= BUS_DMA_COULD_BOUNCE;
284
285 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
286 (flags & BUS_DMA_ALLOCNOW) != 0) {
287 struct bounce_zone *bz;
288
289 /* Must bounce */
290
291 if ((error = alloc_bounce_zone(newtag)) != 0) {
292 free(newtag, M_DEVBUF);
293 return (error);
294 }
295 bz = newtag->bounce_zone;
296
297 if (ptoa(bz->total_bpages) < maxsize) {
298 int pages;
299
300 pages = atop(maxsize) - bz->total_bpages;
301
302 /* Add pages to our bounce pool */
303 if (alloc_bounce_pages(newtag, pages) < pages)
304 error = ENOMEM;
305 }
306 /* Performed initial allocation */
307 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
308 }
309
310 if (error != 0) {
311 free(newtag, M_DEVBUF);
312 } else {
313 *dmat = newtag;
314 }
315 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
316 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
317 return (error);
318 }
319
320 int
321 bus_dma_tag_destroy(bus_dma_tag_t dmat)
322 {
323 bus_dma_tag_t dmat_copy;
324 int error;
325
326 error = 0;
327 dmat_copy = dmat;
328
329 if (dmat != NULL) {
330
331 if (dmat->map_count != 0) {
332 error = EBUSY;
333 goto out;
334 }
335
336 while (dmat != NULL) {
337 bus_dma_tag_t parent;
338
339 parent = dmat->parent;
340 atomic_subtract_int(&dmat->ref_count, 1);
341 if (dmat->ref_count == 0) {
342 if (dmat->segments != NULL)
343 free(dmat->segments, M_DEVBUF);
344 free(dmat, M_DEVBUF);
345 /*
346 * Last reference count, so
347 * release our reference
348 * count on our parent.
349 */
350 dmat = parent;
351 } else
352 dmat = NULL;
353 }
354 }
355 out:
356 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
357 return (error);
358 }
359
360 /*
361 * Allocate a handle for mapping from kva/uva/physical
362 * address space into bus device space.
363 */
364 int
365 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
366 {
367 int error;
368
369 error = 0;
370
371 if (dmat->segments == NULL) {
372 dmat->segments = (bus_dma_segment_t *)malloc(
373 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
374 M_NOWAIT);
375 if (dmat->segments == NULL) {
376 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
377 __func__, dmat, ENOMEM);
378 return (ENOMEM);
379 }
380 }
381
382 /*
383 * Bouncing might be required if the driver asks for an active
384 * exclusion region, a data alignment that is stricter than 1, and/or
385 * an active address boundary.
386 */
387 if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
388
389 /* Must bounce */
390 struct bounce_zone *bz;
391 int maxpages;
392
393 if (dmat->bounce_zone == NULL) {
394 if ((error = alloc_bounce_zone(dmat)) != 0)
395 return (error);
396 }
397 bz = dmat->bounce_zone;
398
399 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
400 M_NOWAIT | M_ZERO);
401 if (*mapp == NULL) {
402 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
403 __func__, dmat, ENOMEM);
404 return (ENOMEM);
405 }
406
407 /* Initialize the new map */
408 STAILQ_INIT(&((*mapp)->bpages));
409
410 /*
411 * Attempt to add pages to our pool on a per-instance
412 * basis up to a sane limit.
413 */
414 if (dmat->alignment > 1)
415 maxpages = MAX_BPAGES;
416 else
417 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr));
418 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
419 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
420 int pages;
421
422 pages = MAX(atop(dmat->maxsize), 1);
423 pages = MIN(maxpages - bz->total_bpages, pages);
424 pages = MAX(pages, 1);
425 if (alloc_bounce_pages(dmat, pages) < pages)
426 error = ENOMEM;
427
428 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
429 if (error == 0)
430 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
431 } else {
432 error = 0;
433 }
434 }
435 } else {
436 *mapp = NULL;
437 }
438 if (error == 0)
439 dmat->map_count++;
440 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
441 __func__, dmat, dmat->flags, error);
442 return (error);
443 }
444
445 /*
446 * Destroy a handle for mapping from kva/uva/physical
447 * address space into bus device space.
448 */
449 int
450 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
451 {
452 if (map != NULL && map != &nobounce_dmamap) {
453 if (STAILQ_FIRST(&map->bpages) != NULL) {
454 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
455 __func__, dmat, EBUSY);
456 return (EBUSY);
457 }
458 free(map, M_DEVBUF);
459 }
460 dmat->map_count--;
461 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
462 return (0);
463 }
464
465
466 /*
467 * Allocate a piece of memory that can be efficiently mapped into
468 * bus device space based on the constraints lited in the dma tag.
469 * A dmamap to for use with dmamap_load is also allocated.
470 */
471 int
472 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
473 bus_dmamap_t *mapp)
474 {
475 int mflags;
476
477 if (flags & BUS_DMA_NOWAIT)
478 mflags = M_NOWAIT;
479 else
480 mflags = M_WAITOK;
481 if (flags & BUS_DMA_ZERO)
482 mflags |= M_ZERO;
483
484 /* If we succeed, no mapping/bouncing will be required */
485 *mapp = NULL;
486
487 if (dmat->segments == NULL) {
488 dmat->segments = (bus_dma_segment_t *)malloc(
489 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
490 M_NOWAIT);
491 if (dmat->segments == NULL) {
492 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
493 __func__, dmat, dmat->flags, ENOMEM);
494 return (ENOMEM);
495 }
496 }
497
498 /*
499 * XXX:
500 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
501 * alignment guarantees of malloc need to be nailed down, and the
502 * code below should be rewritten to take that into account.
503 *
504 * In the meantime, we'll warn the user if malloc gets it wrong.
505 */
506 if ((dmat->maxsize <= PAGE_SIZE) &&
507 (dmat->alignment < dmat->maxsize) &&
508 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
509 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
510 } else {
511 /*
512 * XXX Use Contigmalloc until it is merged into this facility
513 * and handles multi-seg allocations. Nobody is doing
514 * multi-seg allocations yet though.
515 * XXX Certain AGP hardware does.
516 */
517 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
518 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
519 dmat->boundary);
520 }
521 if (*vaddr == NULL) {
522 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
523 __func__, dmat, dmat->flags, ENOMEM);
524 return (ENOMEM);
525 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) {
526 printf("bus_dmamem_alloc failed to align memory properly.\n");
527 }
528 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
529 __func__, dmat, dmat->flags, ENOMEM);
530 return (0);
531 }
532
533 /*
534 * Free a piece of memory and it's allociated dmamap, that was allocated
535 * via bus_dmamem_alloc. Make the same choice for free/contigfree.
536 */
537 void
538 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
539 {
540 /*
541 * dmamem does not need to be bounced, so the map should be
542 * NULL
543 */
544 if (map != NULL)
545 panic("bus_dmamem_free: Invalid map freed\n");
546 if ((dmat->maxsize <= PAGE_SIZE) &&
547 (dmat->alignment < dmat->maxsize) &&
548 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
549 free(vaddr, M_DEVBUF);
550 else {
551 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
552 }
553 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
554 }
555
556 /*
557 * Utility function to load a linear buffer. lastaddrp holds state
558 * between invocations (for multiple-buffer loads). segp contains
559 * the starting segment on entrace, and the ending segment on exit.
560 * first indicates if this is the first invocation of this function.
561 */
562 static __inline int
563 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
564 bus_dmamap_t map,
565 void *buf, bus_size_t buflen,
566 pmap_t pmap,
567 int flags,
568 bus_addr_t *lastaddrp,
569 bus_dma_segment_t *segs,
570 int *segp,
571 int first)
572 {
573 bus_size_t sgsize;
574 bus_addr_t curaddr, lastaddr, baddr, bmask;
575 vm_offset_t vaddr;
576 bus_addr_t paddr;
577 int needbounce = 0;
578 int seg;
579
580 if (map == NULL)
581 map = &nobounce_dmamap;
582
583 if ((map != &nobounce_dmamap && map->pagesneeded == 0)
584 && ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0)) {
585 vm_offset_t vendaddr;
586
587 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
588 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
589 dmat->boundary, dmat->alignment);
590 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
591 map, &nobounce_dmamap, map->pagesneeded);
592 /*
593 * Count the number of bounce pages
594 * needed in order to complete this transfer
595 */
596 vaddr = trunc_page((vm_offset_t)buf);
597 vendaddr = (vm_offset_t)buf + buflen;
598
599 while (vaddr < vendaddr) {
600 paddr = pmap_kextract(vaddr);
601 if (run_filter(dmat, paddr) != 0) {
602 needbounce = 1;
603 map->pagesneeded++;
604 }
605 vaddr += PAGE_SIZE;
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 vaddr = (vm_offset_t)buf;
634 lastaddr = *lastaddrp;
635 bmask = ~(dmat->boundary - 1);
636
637 for (seg = *segp; buflen > 0 ; ) {
638 /*
639 * Get the physical address for this segment.
640 */
641 if (pmap)
642 curaddr = pmap_extract(pmap, vaddr);
643 else
644 curaddr = pmap_kextract(vaddr);
645
646 /*
647 * Compute the segment size, and adjust counts.
648 */
649 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
650 if (buflen < sgsize)
651 sgsize = buflen;
652
653 /*
654 * Make sure we don't cross any boundaries.
655 */
656 if (dmat->boundary > 0) {
657 baddr = (curaddr + dmat->boundary) & bmask;
658 if (sgsize > (baddr - curaddr))
659 sgsize = (baddr - curaddr);
660 }
661
662 if (map->pagesneeded != 0 && run_filter(dmat, curaddr))
663 curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
664
665 /*
666 * Insert chunk into a segment, coalescing with
667 * previous segment if possible.
668 */
669 if (first) {
670 segs[seg].ds_addr = curaddr;
671 segs[seg].ds_len = sgsize;
672 first = 0;
673 } else {
674 if (needbounce == 0 && curaddr == lastaddr &&
675 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
676 (dmat->boundary == 0 ||
677 (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
678 segs[seg].ds_len += sgsize;
679 else {
680 if (++seg >= dmat->nsegments)
681 break;
682 segs[seg].ds_addr = curaddr;
683 segs[seg].ds_len = sgsize;
684 }
685 }
686
687 lastaddr = curaddr + sgsize;
688 vaddr += sgsize;
689 buflen -= sgsize;
690 }
691
692 *segp = seg;
693 *lastaddrp = lastaddr;
694
695 /*
696 * Did we fit?
697 */
698 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
699 }
700
701 /*
702 * Map the buffer buf into bus space using the dmamap map.
703 */
704 int
705 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
706 bus_size_t buflen, bus_dmamap_callback_t *callback,
707 void *callback_arg, int flags)
708 {
709 bus_addr_t lastaddr = 0;
710 int error, nsegs = 0;
711
712 if (map != NULL) {
713 flags |= BUS_DMA_WAITOK;
714 map->callback = callback;
715 map->callback_arg = callback_arg;
716 }
717
718 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
719 &lastaddr, dmat->segments, &nsegs, 1);
720
721 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
722 __func__, dmat, dmat->flags, error, nsegs + 1);
723
724 if (error == EINPROGRESS) {
725 return (error);
726 }
727
728 if (error)
729 (*callback)(callback_arg, dmat->segments, 0, error);
730 else
731 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
732
733 /*
734 * Return ENOMEM to the caller so that it can pass it up the stack.
735 * This error only happens when NOWAIT is set, so deferal is disabled.
736 */
737 if (error == ENOMEM)
738 return (error);
739
740 return (0);
741 }
742
743
744 /*
745 * Like _bus_dmamap_load(), but for mbufs.
746 */
747 int
748 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
749 struct mbuf *m0,
750 bus_dmamap_callback2_t *callback, void *callback_arg,
751 int flags)
752 {
753 int nsegs, error;
754
755 M_ASSERTPKTHDR(m0);
756
757 flags |= BUS_DMA_NOWAIT;
758 nsegs = 0;
759 error = 0;
760 if (m0->m_pkthdr.len <= dmat->maxsize) {
761 int first = 1;
762 bus_addr_t lastaddr = 0;
763 struct mbuf *m;
764
765 for (m = m0; m != NULL && error == 0; m = m->m_next) {
766 if (m->m_len > 0) {
767 error = _bus_dmamap_load_buffer(dmat, map,
768 m->m_data, m->m_len,
769 NULL, flags, &lastaddr,
770 dmat->segments, &nsegs, first);
771 first = 0;
772 }
773 }
774 } else {
775 error = EINVAL;
776 }
777
778 if (error) {
779 /* force "no valid mappings" in callback */
780 (*callback)(callback_arg, dmat->segments, 0, 0, error);
781 } else {
782 (*callback)(callback_arg, dmat->segments,
783 nsegs+1, m0->m_pkthdr.len, error);
784 }
785 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
786 __func__, dmat, dmat->flags, error, nsegs + 1);
787 return (error);
788 }
789
790 int
791 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
792 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
793 int flags)
794 {
795 int error;
796
797 M_ASSERTPKTHDR(m0);
798
799 flags |= BUS_DMA_NOWAIT;
800 *nsegs = 0;
801 error = 0;
802 if (m0->m_pkthdr.len <= dmat->maxsize) {
803 int first = 1;
804 bus_addr_t lastaddr = 0;
805 struct mbuf *m;
806
807 for (m = m0; m != NULL && error == 0; m = m->m_next) {
808 if (m->m_len > 0) {
809 error = _bus_dmamap_load_buffer(dmat, map,
810 m->m_data, m->m_len,
811 NULL, flags, &lastaddr,
812 segs, nsegs, first);
813 first = 0;
814 }
815 }
816 } else {
817 error = EINVAL;
818 }
819
820 /* XXX FIXME: Having to increment nsegs is really annoying */
821 ++*nsegs;
822 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
823 __func__, dmat, dmat->flags, error, *nsegs);
824 return (error);
825 }
826
827 /*
828 * Like _bus_dmamap_load(), but for uios.
829 */
830 int
831 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
832 struct uio *uio,
833 bus_dmamap_callback2_t *callback, void *callback_arg,
834 int flags)
835 {
836 bus_addr_t lastaddr;
837 int nsegs, error, first, i;
838 bus_size_t resid;
839 struct iovec *iov;
840 pmap_t pmap;
841
842 flags |= BUS_DMA_NOWAIT;
843 resid = uio->uio_resid;
844 iov = uio->uio_iov;
845
846 if (uio->uio_segflg == UIO_USERSPACE) {
847 KASSERT(uio->uio_td != NULL,
848 ("bus_dmamap_load_uio: USERSPACE but no proc"));
849 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
850 } else
851 pmap = NULL;
852
853 nsegs = 0;
854 error = 0;
855 first = 1;
856 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
857 /*
858 * Now at the first iovec to load. Load each iovec
859 * until we have exhausted the residual count.
860 */
861 bus_size_t minlen =
862 resid < iov[i].iov_len ? resid : iov[i].iov_len;
863 caddr_t addr = (caddr_t) iov[i].iov_base;
864
865 if (minlen > 0) {
866 error = _bus_dmamap_load_buffer(dmat, map,
867 addr, minlen, pmap, flags, &lastaddr,
868 dmat->segments, &nsegs, first);
869 first = 0;
870
871 resid -= minlen;
872 }
873 }
874
875 if (error) {
876 /* force "no valid mappings" in callback */
877 (*callback)(callback_arg, dmat->segments, 0, 0, error);
878 } else {
879 (*callback)(callback_arg, dmat->segments,
880 nsegs+1, uio->uio_resid, error);
881 }
882 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
883 __func__, dmat, dmat->flags, error, nsegs + 1);
884 return (error);
885 }
886
887 /*
888 * Release the mapping held by map.
889 */
890 void
891 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
892 {
893 struct bounce_page *bpage;
894
895 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
896 STAILQ_REMOVE_HEAD(&map->bpages, links);
897 free_bounce_page(dmat, bpage);
898 }
899 }
900
901 void
902 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
903 {
904 struct bounce_page *bpage;
905
906 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
907 /*
908 * Handle data bouncing. We might also
909 * want to add support for invalidating
910 * the caches on broken hardware
911 */
912 dmat->bounce_zone->total_bounced++;
913 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
914 "performing bounce", __func__, op, dmat, dmat->flags);
915
916 if (op & BUS_DMASYNC_PREWRITE) {
917 while (bpage != NULL) {
918 bcopy((void *)bpage->datavaddr,
919 (void *)bpage->vaddr,
920 bpage->datacount);
921 bpage = STAILQ_NEXT(bpage, links);
922 }
923 }
924
925 if (op & BUS_DMASYNC_POSTREAD) {
926 while (bpage != NULL) {
927 bcopy((void *)bpage->vaddr,
928 (void *)bpage->datavaddr,
929 bpage->datacount);
930 bpage = STAILQ_NEXT(bpage, links);
931 }
932 }
933 }
934 }
935
936 static void
937 init_bounce_pages(void *dummy __unused)
938 {
939
940 total_bpages = 0;
941 STAILQ_INIT(&bounce_zone_list);
942 STAILQ_INIT(&bounce_map_waitinglist);
943 STAILQ_INIT(&bounce_map_callbacklist);
944 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
945 }
946 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
947
948 static struct sysctl_ctx_list *
949 busdma_sysctl_tree(struct bounce_zone *bz)
950 {
951 return (&bz->sysctl_tree);
952 }
953
954 static struct sysctl_oid *
955 busdma_sysctl_tree_top(struct bounce_zone *bz)
956 {
957 return (bz->sysctl_tree_top);
958 }
959
960 static int
961 alloc_bounce_zone(bus_dma_tag_t dmat)
962 {
963 struct bounce_zone *bz;
964
965 /* Check to see if we already have a suitable zone */
966 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
967 if ((dmat->alignment <= bz->alignment)
968 && (dmat->boundary <= bz->boundary)
969 && (dmat->lowaddr >= bz->lowaddr)) {
970 dmat->bounce_zone = bz;
971 return (0);
972 }
973 }
974
975 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
976 M_NOWAIT | M_ZERO)) == NULL)
977 return (ENOMEM);
978
979 STAILQ_INIT(&bz->bounce_page_list);
980 bz->free_bpages = 0;
981 bz->reserved_bpages = 0;
982 bz->active_bpages = 0;
983 bz->lowaddr = dmat->lowaddr;
984 bz->alignment = dmat->alignment;
985 bz->boundary = dmat->boundary;
986 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
987 busdma_zonecount++;
988 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
989 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
990 dmat->bounce_zone = bz;
991
992 sysctl_ctx_init(&bz->sysctl_tree);
993 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
994 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
995 CTLFLAG_RD, 0, "");
996 if (bz->sysctl_tree_top == NULL) {
997 sysctl_ctx_free(&bz->sysctl_tree);
998 return (0); /* XXX error code? */
999 }
1000
1001 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1002 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1003 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1004 "Total bounce pages");
1005 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1006 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1007 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1008 "Free bounce pages");
1009 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1010 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1011 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1012 "Reserved bounce pages");
1013 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1014 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1015 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1016 "Active bounce pages");
1017 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1018 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1019 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1020 "Total bounce requests");
1021 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1022 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1023 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1024 "Total bounce requests that were deferred");
1025 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1026 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1027 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1028 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1029 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1030 "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1031 SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1032 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1033 "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
1034
1035 return (0);
1036 }
1037
1038 static int
1039 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1040 {
1041 struct bounce_zone *bz;
1042 int count;
1043
1044 bz = dmat->bounce_zone;
1045 count = 0;
1046 while (numpages > 0) {
1047 struct bounce_page *bpage;
1048
1049 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1050 M_NOWAIT | M_ZERO);
1051
1052 if (bpage == NULL)
1053 break;
1054 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1055 M_NOWAIT, 0ul,
1056 bz->lowaddr,
1057 PAGE_SIZE,
1058 bz->boundary);
1059 if (bpage->vaddr == 0) {
1060 free(bpage, M_DEVBUF);
1061 break;
1062 }
1063 bpage->busaddr = pmap_kextract(bpage->vaddr);
1064 mtx_lock(&bounce_lock);
1065 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1066 total_bpages++;
1067 bz->total_bpages++;
1068 bz->free_bpages++;
1069 mtx_unlock(&bounce_lock);
1070 count++;
1071 numpages--;
1072 }
1073 return (count);
1074 }
1075
1076 static int
1077 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1078 {
1079 struct bounce_zone *bz;
1080 int pages;
1081
1082 mtx_assert(&bounce_lock, MA_OWNED);
1083 bz = dmat->bounce_zone;
1084 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1085 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1086 return (map->pagesneeded - (map->pagesreserved + pages));
1087 bz->free_bpages -= pages;
1088 bz->reserved_bpages += pages;
1089 map->pagesreserved += pages;
1090 pages = map->pagesneeded - map->pagesreserved;
1091
1092 return (pages);
1093 }
1094
1095 static bus_addr_t
1096 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1097 bus_size_t size)
1098 {
1099 struct bounce_zone *bz;
1100 struct bounce_page *bpage;
1101
1102 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1103 KASSERT(map != NULL && map != &nobounce_dmamap,
1104 ("add_bounce_page: bad map %p", map));
1105
1106 bz = dmat->bounce_zone;
1107 if (map->pagesneeded == 0)
1108 panic("add_bounce_page: map doesn't need any pages");
1109 map->pagesneeded--;
1110
1111 if (map->pagesreserved == 0)
1112 panic("add_bounce_page: map doesn't need any pages");
1113 map->pagesreserved--;
1114
1115 mtx_lock(&bounce_lock);
1116 bpage = STAILQ_FIRST(&bz->bounce_page_list);
1117 if (bpage == NULL)
1118 panic("add_bounce_page: free page list is empty");
1119
1120 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1121 bz->reserved_bpages--;
1122 bz->active_bpages++;
1123 mtx_unlock(&bounce_lock);
1124
1125 bpage->datavaddr = vaddr;
1126 bpage->datacount = size;
1127 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1128 return (bpage->busaddr);
1129 }
1130
1131 static void
1132 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1133 {
1134 struct bus_dmamap *map;
1135 struct bounce_zone *bz;
1136
1137 bz = dmat->bounce_zone;
1138 bpage->datavaddr = 0;
1139 bpage->datacount = 0;
1140
1141 mtx_lock(&bounce_lock);
1142 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1143 bz->free_bpages++;
1144 bz->active_bpages--;
1145 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1146 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1147 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1148 STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1149 map, links);
1150 busdma_swi_pending = 1;
1151 bz->total_deferred++;
1152 swi_sched(vm_ih, 0);
1153 }
1154 }
1155 mtx_unlock(&bounce_lock);
1156 }
1157
1158 void
1159 busdma_swi(void)
1160 {
1161 bus_dma_tag_t dmat;
1162 struct bus_dmamap *map;
1163
1164 mtx_lock(&bounce_lock);
1165 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1166 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1167 mtx_unlock(&bounce_lock);
1168 dmat = map->dmat;
1169 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1170 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1171 map->callback, map->callback_arg, /*flags*/0);
1172 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1173 mtx_lock(&bounce_lock);
1174 }
1175 mtx_unlock(&bounce_lock);
1176 }
Cache object: 4ed056a8ef0beea73a09ec8280531cbd
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