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