Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/i386/i386/busdma_machdep.c
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1 /*- 2 * Copyright (c) 1997, 1998 Justin T. Gibbs. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions, and the following disclaimer, 10 * without modification, immediately at the beginning of the file. 11 * 2. The name of the author may not be used to endorse or promote products 12 * derived from this software without specific prior written permission. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 18 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/kdb.h> 32 #include <ddb/ddb.h> 33 #include <ddb/db_output.h> 34 #include <sys/systm.h> 35 #include <sys/malloc.h> 36 #include <sys/bus.h> 37 #include <sys/interrupt.h> 38 #include <sys/kernel.h> 39 #include <sys/ktr.h> 40 #include <sys/lock.h> 41 #include <sys/proc.h> 42 #include <sys/mutex.h> 43 #include <sys/mbuf.h> 44 #include <sys/uio.h> 45 #include <sys/sysctl.h> 46 47 #include <vm/vm.h> 48 #include <vm/vm_page.h> 49 #include <vm/vm_map.h> 50 51 #include <machine/atomic.h> 52 #include <machine/bus.h> 53 #include <machine/md_var.h> 54 #include <machine/specialreg.h> 55 56 #define MAX_BPAGES 512 57 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3 58 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 59 60 struct bounce_zone; 61 62 struct bus_dma_tag { 63 bus_dma_tag_t parent; 64 bus_size_t alignment; 65 bus_size_t boundary; 66 bus_addr_t lowaddr; 67 bus_addr_t highaddr; 68 bus_dma_filter_t *filter; 69 void *filterarg; 70 bus_size_t maxsize; 71 u_int nsegments; 72 bus_size_t maxsegsz; 73 int flags; 74 int ref_count; 75 int map_count; 76 bus_dma_lock_t *lockfunc; 77 void *lockfuncarg; 78 bus_dma_segment_t *segments; 79 struct bounce_zone *bounce_zone; 80 }; 81 82 struct bounce_page { 83 vm_offset_t vaddr; /* kva of bounce buffer */ 84 bus_addr_t busaddr; /* Physical address */ 85 vm_offset_t datavaddr; /* kva of client data */ 86 bus_size_t datacount; /* client data count */ 87 STAILQ_ENTRY(bounce_page) links; 88 }; 89 90 int busdma_swi_pending; 91 92 struct bounce_zone { 93 STAILQ_ENTRY(bounce_zone) links; 94 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 95 int total_bpages; 96 int free_bpages; 97 int reserved_bpages; 98 int active_bpages; 99 int total_bounced; 100 int total_deferred; 101 bus_size_t alignment; 102 bus_size_t boundary; 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, void *buf, 145 bus_size_t buflen, int flags, int *nb); 146 147 /* 148 * Return true if a match is made. 149 * 150 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 151 * 152 * If paddr is within the bounds of the dma tag then call the filter callback 153 * to check for a match, if there is no filter callback then assume a match. 154 */ 155 int 156 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 157 { 158 int retval; 159 160 retval = 0; 161 162 do { 163 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) 164 || ((paddr & (dmat->alignment - 1)) != 0)) 165 && (dmat->filter == NULL 166 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 167 retval = 1; 168 169 dmat = dmat->parent; 170 } while (retval == 0 && dmat != NULL); 171 return (retval); 172 } 173 174 /* 175 * Convenience function for manipulating driver locks from busdma (during 176 * busdma_swi, for example). Drivers that don't provide their own locks 177 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own 178 * non-mutex locking scheme don't have to use this at all. 179 */ 180 void 181 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op) 182 { 183 struct mtx *dmtx; 184 185 dmtx = (struct mtx *)arg; 186 switch (op) { 187 case BUS_DMA_LOCK: 188 mtx_lock(dmtx); 189 break; 190 case BUS_DMA_UNLOCK: 191 mtx_unlock(dmtx); 192 break; 193 default: 194 panic("Unknown operation 0x%x for busdma_lock_mutex!", op); 195 } 196 } 197 198 /* 199 * dflt_lock should never get called. It gets put into the dma tag when 200 * lockfunc == NULL, which is only valid if the maps that are associated 201 * with the tag are meant to never be defered. 202 * XXX Should have a way to identify which driver is responsible here. 203 */ 204 static void 205 dflt_lock(void *arg, bus_dma_lock_op_t op) 206 { 207 panic("driver error: busdma dflt_lock called"); 208 } 209 210 /* 211 * Allocate a device specific dma_tag. 212 */ 213 int 214 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 215 bus_size_t boundary, bus_addr_t lowaddr, 216 bus_addr_t highaddr, bus_dma_filter_t *filter, 217 void *filterarg, bus_size_t maxsize, int nsegments, 218 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc, 219 void *lockfuncarg, bus_dma_tag_t *dmat) 220 { 221 bus_dma_tag_t newtag; 222 int error = 0; 223 224 /* Basic sanity checking */ 225 if (boundary != 0 && boundary < maxsegsz) 226 maxsegsz = boundary; 227 228 if (maxsegsz == 0) { 229 return (EINVAL); 230 } 231 232 /* Return a NULL tag on failure */ 233 *dmat = NULL; 234 235 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, 236 M_ZERO | M_NOWAIT); 237 if (newtag == NULL) { 238 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 239 __func__, newtag, 0, error); 240 return (ENOMEM); 241 } 242 243 newtag->parent = parent; 244 newtag->alignment = alignment; 245 newtag->boundary = boundary; 246 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 247 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + 248 (PAGE_SIZE - 1); 249 newtag->filter = filter; 250 newtag->filterarg = filterarg; 251 newtag->maxsize = maxsize; 252 newtag->nsegments = nsegments; 253 newtag->maxsegsz = maxsegsz; 254 newtag->flags = flags; 255 newtag->ref_count = 1; /* Count ourself */ 256 newtag->map_count = 0; 257 if (lockfunc != NULL) { 258 newtag->lockfunc = lockfunc; 259 newtag->lockfuncarg = lockfuncarg; 260 } else { 261 newtag->lockfunc = dflt_lock; 262 newtag->lockfuncarg = NULL; 263 } 264 newtag->segments = NULL; 265 266 /* Take into account any restrictions imposed by our parent tag */ 267 if (parent != NULL) { 268 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 269 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 270 if (newtag->boundary == 0) 271 newtag->boundary = parent->boundary; 272 else if (parent->boundary != 0) 273 newtag->boundary = MIN(parent->boundary, 274 newtag->boundary); 275 if ((newtag->filter != NULL) || 276 ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0)) 277 newtag->flags |= BUS_DMA_COULD_BOUNCE; 278 if (newtag->filter == NULL) { 279 /* 280 * Short circuit looking at our parent directly 281 * since we have encapsulated all of its information 282 */ 283 newtag->filter = parent->filter; 284 newtag->filterarg = parent->filterarg; 285 newtag->parent = parent->parent; 286 } 287 if (newtag->parent != NULL) 288 atomic_add_int(&parent->ref_count, 1); 289 } 290 291 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) 292 || newtag->alignment > 1) 293 newtag->flags |= BUS_DMA_COULD_BOUNCE; 294 295 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) && 296 (flags & BUS_DMA_ALLOCNOW) != 0) { 297 struct bounce_zone *bz; 298 299 /* Must bounce */ 300 301 if ((error = alloc_bounce_zone(newtag)) != 0) { 302 free(newtag, M_DEVBUF); 303 return (error); 304 } 305 bz = newtag->bounce_zone; 306 307 if (ptoa(bz->total_bpages) < maxsize) { 308 int pages; 309 310 pages = atop(maxsize) - bz->total_bpages; 311 312 /* Add pages to our bounce pool */ 313 if (alloc_bounce_pages(newtag, pages) < pages) 314 error = ENOMEM; 315 } 316 /* Performed initial allocation */ 317 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 318 } 319 320 if (error != 0) { 321 free(newtag, M_DEVBUF); 322 } else { 323 *dmat = newtag; 324 } 325 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 326 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error); 327 return (error); 328 } 329 330 int 331 bus_dma_tag_destroy(bus_dma_tag_t dmat) 332 { 333 bus_dma_tag_t dmat_copy; 334 int error; 335 336 error = 0; 337 dmat_copy = dmat; 338 339 if (dmat != NULL) { 340 341 if (dmat->map_count != 0) { 342 error = EBUSY; 343 goto out; 344 } 345 346 while (dmat != NULL) { 347 bus_dma_tag_t parent; 348 349 parent = dmat->parent; 350 atomic_subtract_int(&dmat->ref_count, 1); 351 if (dmat->ref_count == 0) { 352 if (dmat->segments != NULL) 353 free(dmat->segments, M_DEVBUF); 354 free(dmat, M_DEVBUF); 355 /* 356 * Last reference count, so 357 * release our reference 358 * count on our parent. 359 */ 360 dmat = parent; 361 } else 362 dmat = NULL; 363 } 364 } 365 out: 366 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error); 367 return (error); 368 } 369 370 /* 371 * Allocate a handle for mapping from kva/uva/physical 372 * address space into bus device space. 373 */ 374 int 375 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 376 { 377 int error; 378 379 error = 0; 380 381 if (dmat->segments == NULL) { 382 dmat->segments = (bus_dma_segment_t *)malloc( 383 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 384 M_NOWAIT); 385 if (dmat->segments == NULL) { 386 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 387 __func__, dmat, ENOMEM); 388 return (ENOMEM); 389 } 390 } 391 392 /* 393 * Bouncing might be required if the driver asks for an active 394 * exclusion region, a data alignment that is stricter than 1, and/or 395 * an active address boundary. 396 */ 397 if (dmat->flags & BUS_DMA_COULD_BOUNCE) { 398 399 /* Must bounce */ 400 struct bounce_zone *bz; 401 int maxpages; 402 403 if (dmat->bounce_zone == NULL) { 404 if ((error = alloc_bounce_zone(dmat)) != 0) 405 return (error); 406 } 407 bz = dmat->bounce_zone; 408 409 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 410 M_NOWAIT | M_ZERO); 411 if (*mapp == NULL) { 412 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 413 __func__, dmat, ENOMEM); 414 return (ENOMEM); 415 } 416 417 /* Initialize the new map */ 418 STAILQ_INIT(&((*mapp)->bpages)); 419 420 /* 421 * Attempt to add pages to our pool on a per-instance 422 * basis up to a sane limit. 423 */ 424 if (dmat->alignment > 1) 425 maxpages = MAX_BPAGES; 426 else 427 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr)); 428 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 429 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) { 430 int pages; 431 432 pages = MAX(atop(dmat->maxsize), 1); 433 pages = MIN(maxpages - bz->total_bpages, pages); 434 pages = MAX(pages, 1); 435 if (alloc_bounce_pages(dmat, pages) < pages) 436 error = ENOMEM; 437 438 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 439 if (error == 0) 440 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 441 } else { 442 error = 0; 443 } 444 } 445 } else { 446 *mapp = NULL; 447 } 448 if (error == 0) 449 dmat->map_count++; 450 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 451 __func__, dmat, dmat->flags, error); 452 return (error); 453 } 454 455 /* 456 * Destroy a handle for mapping from kva/uva/physical 457 * address space into bus device space. 458 */ 459 int 460 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 461 { 462 if (map != NULL && map != &nobounce_dmamap) { 463 if (STAILQ_FIRST(&map->bpages) != NULL) { 464 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 465 __func__, dmat, EBUSY); 466 return (EBUSY); 467 } 468 free(map, M_DEVBUF); 469 } 470 dmat->map_count--; 471 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat); 472 return (0); 473 } 474 475 476 /* 477 * Allocate a piece of memory that can be efficiently mapped into 478 * bus device space based on the constraints lited in the dma tag. 479 * A dmamap to for use with dmamap_load is also allocated. 480 */ 481 int 482 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 483 bus_dmamap_t *mapp) 484 { 485 int mflags; 486 487 if (flags & BUS_DMA_NOWAIT) 488 mflags = M_NOWAIT; 489 else 490 mflags = M_WAITOK; 491 if (flags & BUS_DMA_ZERO) 492 mflags |= M_ZERO; 493 494 /* If we succeed, no mapping/bouncing will be required */ 495 *mapp = NULL; 496 497 if (dmat->segments == NULL) { 498 dmat->segments = (bus_dma_segment_t *)malloc( 499 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 500 M_NOWAIT); 501 if (dmat->segments == NULL) { 502 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 503 __func__, dmat, dmat->flags, ENOMEM); 504 return (ENOMEM); 505 } 506 } 507 508 /* 509 * XXX: 510 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact 511 * alignment guarantees of malloc need to be nailed down, and the 512 * code below should be rewritten to take that into account. 513 * 514 * In the meantime, we'll warn the user if malloc gets it wrong. 515 */ 516 if ((dmat->maxsize <= PAGE_SIZE) && 517 (dmat->alignment < dmat->maxsize) && 518 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 519 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags); 520 } else { 521 /* 522 * XXX Use Contigmalloc until it is merged into this facility 523 * and handles multi-seg allocations. Nobody is doing 524 * multi-seg allocations yet though. 525 * XXX Certain AGP hardware does. 526 */ 527 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags, 528 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 529 dmat->boundary); 530 } 531 if (*vaddr == NULL) { 532 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 533 __func__, dmat, dmat->flags, ENOMEM); 534 return (ENOMEM); 535 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) { 536 printf("bus_dmamem_alloc failed to align memory properly.\n"); 537 } 538 if (flags & BUS_DMA_NOCACHE) 539 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize, 540 PAT_UNCACHEABLE); 541 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 542 __func__, dmat, dmat->flags, ENOMEM); 543 return (0); 544 } 545 546 /* 547 * Free a piece of memory and it's allociated dmamap, that was allocated 548 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 549 */ 550 void 551 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 552 { 553 /* 554 * dmamem does not need to be bounced, so the map should be 555 * NULL 556 */ 557 if (map != NULL) 558 panic("bus_dmamem_free: Invalid map freed\n"); 559 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK); 560 if ((dmat->maxsize <= PAGE_SIZE) && 561 (dmat->alignment < dmat->maxsize) && 562 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 563 free(vaddr, M_DEVBUF); 564 else { 565 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 566 } 567 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags); 568 } 569 570 int 571 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 572 bus_size_t buflen, int flags, int *nb) 573 { 574 vm_offset_t vaddr; 575 vm_offset_t vendaddr; 576 bus_addr_t paddr; 577 int needbounce = *nb; 578 579 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) { 580 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, " 581 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem), 582 dmat->boundary, dmat->alignment); 583 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d", 584 map, &nobounce_dmamap, map->pagesneeded); 585 /* 586 * Count the number of bounce pages 587 * needed in order to complete this transfer 588 */ 589 vaddr = trunc_page((vm_offset_t)buf); 590 vendaddr = (vm_offset_t)buf + buflen; 591 592 while (vaddr < vendaddr) { 593 paddr = pmap_kextract(vaddr); 594 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) && 595 run_filter(dmat, paddr) != 0) { 596 needbounce = 1; 597 map->pagesneeded++; 598 } 599 vaddr += PAGE_SIZE; 600 } 601 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded); 602 } 603 604 /* Reserve Necessary Bounce Pages */ 605 if (map->pagesneeded != 0) { 606 mtx_lock(&bounce_lock); 607 if (flags & BUS_DMA_NOWAIT) { 608 if (reserve_bounce_pages(dmat, map, 0) != 0) { 609 mtx_unlock(&bounce_lock); 610 return (ENOMEM); 611 } 612 } else { 613 if (reserve_bounce_pages(dmat, map, 1) != 0) { 614 /* Queue us for resources */ 615 map->dmat = dmat; 616 map->buf = buf; 617 map->buflen = buflen; 618 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 619 map, links); 620 mtx_unlock(&bounce_lock); 621 return (EINPROGRESS); 622 } 623 } 624 mtx_unlock(&bounce_lock); 625 } 626 627 *nb = needbounce; 628 return (0); 629 } 630 631 /* 632 * Utility function to load a linear buffer. lastaddrp holds state 633 * between invocations (for multiple-buffer loads). segp contains 634 * the starting segment on entrace, and the ending segment on exit. 635 * first indicates if this is the first invocation of this function. 636 */ 637 static __inline int 638 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, 639 bus_dmamap_t map, 640 void *buf, bus_size_t buflen, 641 pmap_t pmap, 642 int flags, 643 bus_addr_t *lastaddrp, 644 bus_dma_segment_t *segs, 645 int *segp, 646 int first) 647 { 648 bus_size_t sgsize; 649 bus_addr_t curaddr, lastaddr, baddr, bmask; 650 vm_offset_t vaddr; 651 int needbounce = 0; 652 int seg, error; 653 654 if (map == NULL) 655 map = &nobounce_dmamap; 656 657 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) { 658 error = _bus_dmamap_count_pages(dmat, map, buf, buflen, flags, 659 &needbounce); 660 if (error) 661 return (error); 662 } 663 664 vaddr = (vm_offset_t)buf; 665 lastaddr = *lastaddrp; 666 bmask = ~(dmat->boundary - 1); 667 668 for (seg = *segp; buflen > 0 ; ) { 669 /* 670 * Get the physical address for this segment. 671 */ 672 if (pmap) 673 curaddr = pmap_extract(pmap, vaddr); 674 else 675 curaddr = pmap_kextract(vaddr); 676 677 /* 678 * Compute the segment size, and adjust counts. 679 */ 680 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK); 681 if (sgsize > dmat->maxsegsz) 682 sgsize = dmat->maxsegsz; 683 if (buflen < sgsize) 684 sgsize = buflen; 685 686 /* 687 * Make sure we don't cross any boundaries. 688 */ 689 if (dmat->boundary > 0) { 690 baddr = (curaddr + dmat->boundary) & bmask; 691 if (sgsize > (baddr - curaddr)) 692 sgsize = (baddr - curaddr); 693 } 694 695 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) && 696 map->pagesneeded != 0 && run_filter(dmat, curaddr)) 697 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 698 699 /* 700 * Insert chunk into a segment, coalescing with 701 * previous segment if possible. 702 */ 703 if (first) { 704 segs[seg].ds_addr = curaddr; 705 segs[seg].ds_len = sgsize; 706 first = 0; 707 } else { 708 if (needbounce == 0 && curaddr == lastaddr && 709 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 710 (dmat->boundary == 0 || 711 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 712 segs[seg].ds_len += sgsize; 713 else { 714 if (++seg >= dmat->nsegments) 715 break; 716 segs[seg].ds_addr = curaddr; 717 segs[seg].ds_len = sgsize; 718 } 719 } 720 721 lastaddr = curaddr + sgsize; 722 vaddr += sgsize; 723 buflen -= sgsize; 724 } 725 726 *segp = seg; 727 *lastaddrp = lastaddr; 728 729 /* 730 * Did we fit? 731 */ 732 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 733 } 734 735 /* 736 * Map the buffer buf into bus space using the dmamap map. 737 */ 738 int 739 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 740 bus_size_t buflen, bus_dmamap_callback_t *callback, 741 void *callback_arg, int flags) 742 { 743 bus_addr_t lastaddr = 0; 744 int error, nsegs = 0; 745 746 if (map != NULL) { 747 flags |= BUS_DMA_WAITOK; 748 map->callback = callback; 749 map->callback_arg = callback_arg; 750 } 751 752 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags, 753 &lastaddr, dmat->segments, &nsegs, 1); 754 755 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 756 __func__, dmat, dmat->flags, error, nsegs + 1); 757 758 if (error == EINPROGRESS) { 759 return (error); 760 } 761 762 if (error) 763 (*callback)(callback_arg, dmat->segments, 0, error); 764 else 765 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0); 766 767 /* 768 * Return ENOMEM to the caller so that it can pass it up the stack. 769 * This error only happens when NOWAIT is set, so deferal is disabled. 770 */ 771 if (error == ENOMEM) 772 return (error); 773 774 return (0); 775 } 776 777 778 /* 779 * Like _bus_dmamap_load(), but for mbufs. 780 */ 781 static __inline int 782 _bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 783 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 784 int flags) 785 { 786 int error; 787 788 M_ASSERTPKTHDR(m0); 789 790 flags |= BUS_DMA_NOWAIT; 791 *nsegs = 0; 792 error = 0; 793 if (m0->m_pkthdr.len <= dmat->maxsize) { 794 int first = 1; 795 bus_addr_t lastaddr = 0; 796 struct mbuf *m; 797 798 for (m = m0; m != NULL && error == 0; m = m->m_next) { 799 if (m->m_len > 0) { 800 error = _bus_dmamap_load_buffer(dmat, map, 801 m->m_data, m->m_len, 802 NULL, flags, &lastaddr, 803 segs, nsegs, first); 804 first = 0; 805 } 806 } 807 } else { 808 error = EINVAL; 809 } 810 811 /* XXX FIXME: Having to increment nsegs is really annoying */ 812 ++*nsegs; 813 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 814 __func__, dmat, dmat->flags, error, *nsegs); 815 return (error); 816 } 817 818 int 819 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 820 struct mbuf *m0, 821 bus_dmamap_callback2_t *callback, void *callback_arg, 822 int flags) 823 { 824 int nsegs, error; 825 826 error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, dmat->segments, &nsegs, 827 flags); 828 829 if (error) { 830 /* force "no valid mappings" in callback */ 831 (*callback)(callback_arg, dmat->segments, 0, 0, error); 832 } else { 833 (*callback)(callback_arg, dmat->segments, 834 nsegs, m0->m_pkthdr.len, error); 835 } 836 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 837 __func__, dmat, dmat->flags, error, nsegs); 838 return (error); 839 } 840 841 int 842 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 843 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 844 int flags) 845 { 846 return (_bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags)); 847 } 848 849 /* 850 * Like _bus_dmamap_load(), but for uios. 851 */ 852 int 853 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 854 struct uio *uio, 855 bus_dmamap_callback2_t *callback, void *callback_arg, 856 int flags) 857 { 858 bus_addr_t lastaddr; 859 int nsegs, error, first, i; 860 bus_size_t resid; 861 struct iovec *iov; 862 pmap_t pmap; 863 864 flags |= BUS_DMA_NOWAIT; 865 resid = uio->uio_resid; 866 iov = uio->uio_iov; 867 868 if (uio->uio_segflg == UIO_USERSPACE) { 869 KASSERT(uio->uio_td != NULL, 870 ("bus_dmamap_load_uio: USERSPACE but no proc")); 871 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace); 872 } else 873 pmap = NULL; 874 875 nsegs = 0; 876 error = 0; 877 first = 1; 878 lastaddr = (bus_addr_t) 0; 879 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 880 /* 881 * Now at the first iovec to load. Load each iovec 882 * until we have exhausted the residual count. 883 */ 884 bus_size_t minlen = 885 resid < iov[i].iov_len ? resid : iov[i].iov_len; 886 caddr_t addr = (caddr_t) iov[i].iov_base; 887 888 if (minlen > 0) { 889 error = _bus_dmamap_load_buffer(dmat, map, 890 addr, minlen, pmap, flags, &lastaddr, 891 dmat->segments, &nsegs, first); 892 first = 0; 893 894 resid -= minlen; 895 } 896 } 897 898 if (error) { 899 /* force "no valid mappings" in callback */ 900 (*callback)(callback_arg, dmat->segments, 0, 0, error); 901 } else { 902 (*callback)(callback_arg, dmat->segments, 903 nsegs+1, uio->uio_resid, error); 904 } 905 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 906 __func__, dmat, dmat->flags, error, nsegs + 1); 907 return (error); 908 } 909 910 /* 911 * Release the mapping held by map. 912 */ 913 void 914 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 915 { 916 struct bounce_page *bpage; 917 918 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 919 STAILQ_REMOVE_HEAD(&map->bpages, links); 920 free_bounce_page(dmat, bpage); 921 } 922 } 923 924 void 925 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 926 { 927 struct bounce_page *bpage; 928 929 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 930 /* 931 * Handle data bouncing. We might also 932 * want to add support for invalidating 933 * the caches on broken hardware 934 */ 935 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x " 936 "performing bounce", __func__, op, dmat, dmat->flags); 937 938 if (op & BUS_DMASYNC_PREWRITE) { 939 while (bpage != NULL) { 940 bcopy((void *)bpage->datavaddr, 941 (void *)bpage->vaddr, 942 bpage->datacount); 943 bpage = STAILQ_NEXT(bpage, links); 944 } 945 dmat->bounce_zone->total_bounced++; 946 } 947 948 if (op & BUS_DMASYNC_POSTREAD) { 949 while (bpage != NULL) { 950 bcopy((void *)bpage->vaddr, 951 (void *)bpage->datavaddr, 952 bpage->datacount); 953 bpage = STAILQ_NEXT(bpage, links); 954 } 955 dmat->bounce_zone->total_bounced++; 956 } 957 } 958 } 959 960 static void 961 init_bounce_pages(void *dummy __unused) 962 { 963 964 total_bpages = 0; 965 STAILQ_INIT(&bounce_zone_list); 966 STAILQ_INIT(&bounce_map_waitinglist); 967 STAILQ_INIT(&bounce_map_callbacklist); 968 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 969 } 970 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 971 972 static struct sysctl_ctx_list * 973 busdma_sysctl_tree(struct bounce_zone *bz) 974 { 975 return (&bz->sysctl_tree); 976 } 977 978 static struct sysctl_oid * 979 busdma_sysctl_tree_top(struct bounce_zone *bz) 980 { 981 return (bz->sysctl_tree_top); 982 } 983 984 static int 985 alloc_bounce_zone(bus_dma_tag_t dmat) 986 { 987 struct bounce_zone *bz; 988 989 /* Check to see if we already have a suitable zone */ 990 STAILQ_FOREACH(bz, &bounce_zone_list, links) { 991 if ((dmat->alignment <= bz->alignment) 992 && (dmat->boundary <= bz->boundary) 993 && (dmat->lowaddr >= bz->lowaddr)) { 994 dmat->bounce_zone = bz; 995 return (0); 996 } 997 } 998 999 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF, 1000 M_NOWAIT | M_ZERO)) == NULL) 1001 return (ENOMEM); 1002 1003 STAILQ_INIT(&bz->bounce_page_list); 1004 bz->free_bpages = 0; 1005 bz->reserved_bpages = 0; 1006 bz->active_bpages = 0; 1007 bz->lowaddr = dmat->lowaddr; 1008 bz->alignment = dmat->alignment; 1009 bz->boundary = dmat->boundary; 1010 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount); 1011 busdma_zonecount++; 1012 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr); 1013 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links); 1014 dmat->bounce_zone = bz; 1015 1016 sysctl_ctx_init(&bz->sysctl_tree); 1017 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree, 1018 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid, 1019 CTLFLAG_RD, 0, ""); 1020 if (bz->sysctl_tree_top == NULL) { 1021 sysctl_ctx_free(&bz->sysctl_tree); 1022 return (0); /* XXX error code? */ 1023 } 1024 1025 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1026 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1027 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0, 1028 "Total bounce pages"); 1029 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1030 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1031 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0, 1032 "Free bounce pages"); 1033 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1034 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1035 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0, 1036 "Reserved bounce pages"); 1037 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1038 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1039 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0, 1040 "Active bounce pages"); 1041 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1042 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1043 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0, 1044 "Total bounce requests"); 1045 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1046 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1047 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0, 1048 "Total bounce requests that were deferred"); 1049 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz), 1050 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1051 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, ""); 1052 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1053 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1054 "alignment", CTLFLAG_RD, &bz->alignment, 0, ""); 1055 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1056 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1057 "boundary", CTLFLAG_RD, &bz->boundary, 0, ""); 1058 1059 return (0); 1060 } 1061 1062 static int 1063 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 1064 { 1065 struct bounce_zone *bz; 1066 int count; 1067 1068 bz = dmat->bounce_zone; 1069 count = 0; 1070 while (numpages > 0) { 1071 struct bounce_page *bpage; 1072 1073 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 1074 M_NOWAIT | M_ZERO); 1075 1076 if (bpage == NULL) 1077 break; 1078 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 1079 M_NOWAIT, 0ul, 1080 bz->lowaddr, 1081 PAGE_SIZE, 1082 bz->boundary); 1083 if (bpage->vaddr == 0) { 1084 free(bpage, M_DEVBUF); 1085 break; 1086 } 1087 bpage->busaddr = pmap_kextract(bpage->vaddr); 1088 mtx_lock(&bounce_lock); 1089 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links); 1090 total_bpages++; 1091 bz->total_bpages++; 1092 bz->free_bpages++; 1093 mtx_unlock(&bounce_lock); 1094 count++; 1095 numpages--; 1096 } 1097 return (count); 1098 } 1099 1100 static int 1101 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 1102 { 1103 struct bounce_zone *bz; 1104 int pages; 1105 1106 mtx_assert(&bounce_lock, MA_OWNED); 1107 bz = dmat->bounce_zone; 1108 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved); 1109 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 1110 return (map->pagesneeded - (map->pagesreserved + pages)); 1111 bz->free_bpages -= pages; 1112 bz->reserved_bpages += pages; 1113 map->pagesreserved += pages; 1114 pages = map->pagesneeded - map->pagesreserved; 1115 1116 return (pages); 1117 } 1118 1119 static bus_addr_t 1120 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 1121 bus_size_t size) 1122 { 1123 struct bounce_zone *bz; 1124 struct bounce_page *bpage; 1125 1126 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag")); 1127 KASSERT(map != NULL && map != &nobounce_dmamap, 1128 ("add_bounce_page: bad map %p", map)); 1129 1130 bz = dmat->bounce_zone; 1131 if (map->pagesneeded == 0) 1132 panic("add_bounce_page: map doesn't need any pages"); 1133 map->pagesneeded--; 1134 1135 if (map->pagesreserved == 0) 1136 panic("add_bounce_page: map doesn't need any pages"); 1137 map->pagesreserved--; 1138 1139 mtx_lock(&bounce_lock); 1140 bpage = STAILQ_FIRST(&bz->bounce_page_list); 1141 if (bpage == NULL) 1142 panic("add_bounce_page: free page list is empty"); 1143 1144 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links); 1145 bz->reserved_bpages--; 1146 bz->active_bpages++; 1147 mtx_unlock(&bounce_lock); 1148 1149 bpage->datavaddr = vaddr; 1150 bpage->datacount = size; 1151 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 1152 return (bpage->busaddr); 1153 } 1154 1155 static void 1156 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 1157 { 1158 struct bus_dmamap *map; 1159 struct bounce_zone *bz; 1160 1161 bz = dmat->bounce_zone; 1162 bpage->datavaddr = 0; 1163 bpage->datacount = 0; 1164 1165 mtx_lock(&bounce_lock); 1166 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links); 1167 bz->free_bpages++; 1168 bz->active_bpages--; 1169 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 1170 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 1171 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 1172 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 1173 map, links); 1174 busdma_swi_pending = 1; 1175 bz->total_deferred++; 1176 swi_sched(vm_ih, 0); 1177 } 1178 } 1179 mtx_unlock(&bounce_lock); 1180 } 1181 1182 void 1183 busdma_swi(void) 1184 { 1185 bus_dma_tag_t dmat; 1186 struct bus_dmamap *map; 1187 1188 mtx_lock(&bounce_lock); 1189 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 1190 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 1191 mtx_unlock(&bounce_lock); 1192 dmat = map->dmat; 1193 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK); 1194 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 1195 map->callback, map->callback_arg, /*flags*/0); 1196 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK); 1197 mtx_lock(&bounce_lock); 1198 } 1199 mtx_unlock(&bounce_lock); 1200 }
Cache object: 9a2d6256f8e8d67505d5f8d2946168ab
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