Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/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/systm.h> 32 #include <sys/malloc.h> 33 #include <sys/bus.h> 34 #include <sys/interrupt.h> 35 #include <sys/kernel.h> 36 #include <sys/ktr.h> 37 #include <sys/lock.h> 38 #include <sys/proc.h> 39 #include <sys/mutex.h> 40 #include <sys/mbuf.h> 41 #include <sys/uio.h> 42 #include <sys/sysctl.h> 43 44 #include <vm/vm.h> 45 #include <vm/vm_page.h> 46 #include <vm/vm_map.h> 47 48 #include <machine/atomic.h> 49 #include <machine/bus.h> 50 #include <machine/md_var.h> 51 #include <machine/specialreg.h> 52 53 #define MAX_BPAGES 8192 54 55 struct bounce_zone; 56 57 struct bus_dma_tag { 58 bus_dma_tag_t parent; 59 bus_size_t alignment; 60 bus_size_t boundary; 61 bus_addr_t lowaddr; 62 bus_addr_t highaddr; 63 bus_dma_filter_t *filter; 64 void *filterarg; 65 bus_size_t maxsize; 66 u_int nsegments; 67 bus_size_t maxsegsz; 68 int flags; 69 int ref_count; 70 int map_count; 71 bus_dma_lock_t *lockfunc; 72 void *lockfuncarg; 73 bus_dma_segment_t *segments; 74 struct bounce_zone *bounce_zone; 75 }; 76 77 struct bounce_page { 78 vm_offset_t vaddr; /* kva of bounce buffer */ 79 bus_addr_t busaddr; /* Physical address */ 80 vm_offset_t datavaddr; /* kva of client data */ 81 bus_size_t datacount; /* client data count */ 82 STAILQ_ENTRY(bounce_page) links; 83 }; 84 85 int busdma_swi_pending; 86 87 struct bounce_zone { 88 STAILQ_ENTRY(bounce_zone) links; 89 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 90 int total_bpages; 91 int free_bpages; 92 int reserved_bpages; 93 int active_bpages; 94 int total_bounced; 95 int total_deferred; 96 bus_size_t alignment; 97 bus_addr_t lowaddr; 98 char zoneid[8]; 99 char lowaddrid[20]; 100 struct sysctl_ctx_list sysctl_tree; 101 struct sysctl_oid *sysctl_tree_top; 102 }; 103 104 static struct mtx bounce_lock; 105 static int total_bpages; 106 static int busdma_zonecount; 107 static STAILQ_HEAD(, bounce_zone) bounce_zone_list; 108 109 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters"); 110 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0, 111 "Total bounce pages"); 112 113 struct bus_dmamap { 114 struct bp_list bpages; 115 int pagesneeded; 116 int pagesreserved; 117 bus_dma_tag_t dmat; 118 void *buf; /* unmapped buffer pointer */ 119 bus_size_t buflen; /* unmapped buffer length */ 120 bus_dmamap_callback_t *callback; 121 void *callback_arg; 122 STAILQ_ENTRY(bus_dmamap) links; 123 }; 124 125 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 126 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 127 static struct bus_dmamap nobounce_dmamap; 128 129 static void init_bounce_pages(void *dummy); 130 static int alloc_bounce_zone(bus_dma_tag_t dmat); 131 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 132 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, 133 int commit); 134 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 135 vm_offset_t vaddr, bus_size_t size); 136 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 137 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 138 139 /* 140 * Return true if a match is made. 141 * 142 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 143 * 144 * If paddr is within the bounds of the dma tag then call the filter callback 145 * to check for a match, if there is no filter callback then assume a match. 146 */ 147 static __inline int 148 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 149 { 150 int retval; 151 152 retval = 0; 153 154 do { 155 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) 156 || ((paddr & (dmat->alignment - 1)) != 0)) 157 && (dmat->filter == NULL 158 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 159 retval = 1; 160 161 dmat = dmat->parent; 162 } while (retval == 0 && dmat != NULL); 163 return (retval); 164 } 165 166 /* 167 * Convenience function for manipulating driver locks from busdma (during 168 * busdma_swi, for example). Drivers that don't provide their own locks 169 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own 170 * non-mutex locking scheme don't have to use this at all. 171 */ 172 void 173 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op) 174 { 175 struct mtx *dmtx; 176 177 dmtx = (struct mtx *)arg; 178 switch (op) { 179 case BUS_DMA_LOCK: 180 mtx_lock(dmtx); 181 break; 182 case BUS_DMA_UNLOCK: 183 mtx_unlock(dmtx); 184 break; 185 default: 186 panic("Unknown operation 0x%x for busdma_lock_mutex!", op); 187 } 188 } 189 190 /* 191 * dflt_lock should never get called. It gets put into the dma tag when 192 * lockfunc == NULL, which is only valid if the maps that are associated 193 * with the tag are meant to never be defered. 194 * XXX Should have a way to identify which driver is responsible here. 195 */ 196 static void 197 dflt_lock(void *arg, bus_dma_lock_op_t op) 198 { 199 panic("driver error: busdma dflt_lock called"); 200 } 201 202 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3 203 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 204 /* 205 * Allocate a device specific dma_tag. 206 */ 207 int 208 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 209 bus_size_t boundary, bus_addr_t lowaddr, 210 bus_addr_t highaddr, bus_dma_filter_t *filter, 211 void *filterarg, bus_size_t maxsize, int nsegments, 212 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc, 213 void *lockfuncarg, bus_dma_tag_t *dmat) 214 { 215 bus_dma_tag_t newtag; 216 int error = 0; 217 218 /* Always enforce at least a 4GB boundary. */ 219 if (boundary == 0 || boundary > ((bus_addr_t)1 << 32)) 220 boundary = (bus_size_t)1 << 32; 221 222 /* Basic sanity checking */ 223 if (boundary != 0 && boundary < maxsegsz) 224 maxsegsz = boundary; 225 226 if (maxsegsz == 0) { 227 return (EINVAL); 228 } 229 230 /* Return a NULL tag on failure */ 231 *dmat = NULL; 232 233 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, 234 M_ZERO | M_NOWAIT); 235 if (newtag == NULL) { 236 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 237 __func__, newtag, 0, error); 238 return (ENOMEM); 239 } 240 241 newtag->parent = parent; 242 newtag->alignment = alignment; 243 newtag->boundary = boundary; 244 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 245 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + 246 (PAGE_SIZE - 1); 247 newtag->filter = filter; 248 newtag->filterarg = filterarg; 249 newtag->maxsize = maxsize; 250 newtag->nsegments = nsegments; 251 newtag->maxsegsz = maxsegsz; 252 newtag->flags = flags; 253 newtag->ref_count = 1; /* Count ourself */ 254 newtag->map_count = 0; 255 if (lockfunc != NULL) { 256 newtag->lockfunc = lockfunc; 257 newtag->lockfuncarg = lockfuncarg; 258 } else { 259 newtag->lockfunc = dflt_lock; 260 newtag->lockfuncarg = NULL; 261 } 262 newtag->segments = NULL; 263 264 /* Take into account any restrictions imposed by our parent tag */ 265 if (parent != NULL) { 266 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 267 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 268 if (newtag->boundary == 0) 269 newtag->boundary = parent->boundary; 270 else if (parent->boundary != 0) 271 newtag->boundary = MIN(parent->boundary, 272 newtag->boundary); 273 if (newtag->filter == NULL) { 274 /* 275 * Short circuit looking at our parent directly 276 * since we have encapsulated all of its information 277 */ 278 newtag->filter = parent->filter; 279 newtag->filterarg = parent->filterarg; 280 newtag->parent = parent->parent; 281 } 282 if (newtag->parent != NULL) 283 atomic_add_int(&parent->ref_count, 1); 284 } 285 286 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) 287 || newtag->alignment > 1) 288 newtag->flags |= BUS_DMA_COULD_BOUNCE; 289 290 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) && 291 (flags & BUS_DMA_ALLOCNOW) != 0) { 292 struct bounce_zone *bz; 293 294 /* Must bounce */ 295 296 if ((error = alloc_bounce_zone(newtag)) != 0) { 297 free(newtag, M_DEVBUF); 298 return (error); 299 } 300 bz = newtag->bounce_zone; 301 302 if (ptoa(bz->total_bpages) < maxsize) { 303 int pages; 304 305 pages = atop(maxsize) - bz->total_bpages; 306 307 /* Add pages to our bounce pool */ 308 if (alloc_bounce_pages(newtag, pages) < pages) 309 error = ENOMEM; 310 } 311 /* Performed initial allocation */ 312 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 313 } 314 315 if (error != 0) { 316 free(newtag, M_DEVBUF); 317 } else { 318 *dmat = newtag; 319 } 320 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 321 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error); 322 return (error); 323 } 324 325 int 326 bus_dma_tag_destroy(bus_dma_tag_t dmat) 327 { 328 bus_dma_tag_t dmat_copy; 329 int error; 330 331 error = 0; 332 dmat_copy = dmat; 333 334 if (dmat != NULL) { 335 336 if (dmat->map_count != 0) { 337 error = EBUSY; 338 goto out; 339 } 340 341 while (dmat != NULL) { 342 bus_dma_tag_t parent; 343 344 parent = dmat->parent; 345 atomic_subtract_int(&dmat->ref_count, 1); 346 if (dmat->ref_count == 0) { 347 if (dmat->segments != NULL) 348 free(dmat->segments, M_DEVBUF); 349 free(dmat, M_DEVBUF); 350 /* 351 * Last reference count, so 352 * release our reference 353 * count on our parent. 354 */ 355 dmat = parent; 356 } else 357 dmat = NULL; 358 } 359 } 360 out: 361 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error); 362 return (error); 363 } 364 365 /* 366 * Allocate a handle for mapping from kva/uva/physical 367 * address space into bus device space. 368 */ 369 int 370 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 371 { 372 int error; 373 374 error = 0; 375 376 if (dmat->segments == NULL) { 377 dmat->segments = (bus_dma_segment_t *)malloc( 378 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 379 M_NOWAIT); 380 if (dmat->segments == NULL) { 381 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 382 __func__, dmat, ENOMEM); 383 return (ENOMEM); 384 } 385 } 386 387 /* 388 * Bouncing might be required if the driver asks for an active 389 * exclusion region, a data alignment that is stricter than 1, and/or 390 * an active address boundary. 391 */ 392 if (dmat->flags & BUS_DMA_COULD_BOUNCE) { 393 394 /* Must bounce */ 395 struct bounce_zone *bz; 396 int maxpages; 397 398 if (dmat->bounce_zone == NULL) { 399 if ((error = alloc_bounce_zone(dmat)) != 0) 400 return (error); 401 } 402 bz = dmat->bounce_zone; 403 404 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 405 M_NOWAIT | M_ZERO); 406 if (*mapp == NULL) { 407 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 408 __func__, dmat, ENOMEM); 409 return (ENOMEM); 410 } 411 412 /* Initialize the new map */ 413 STAILQ_INIT(&((*mapp)->bpages)); 414 415 /* 416 * Attempt to add pages to our pool on a per-instance 417 * basis up to a sane limit. 418 */ 419 if (dmat->alignment > 1) 420 maxpages = MAX_BPAGES; 421 else 422 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr)); 423 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 424 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) { 425 int pages; 426 427 pages = MAX(atop(dmat->maxsize), 1); 428 pages = MIN(maxpages - bz->total_bpages, pages); 429 pages = MAX(pages, 1); 430 if (alloc_bounce_pages(dmat, pages) < pages) 431 error = ENOMEM; 432 433 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 434 if (error == 0) 435 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 436 } else { 437 error = 0; 438 } 439 } 440 } else { 441 *mapp = NULL; 442 } 443 if (error == 0) 444 dmat->map_count++; 445 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 446 __func__, dmat, dmat->flags, error); 447 return (error); 448 } 449 450 /* 451 * Destroy a handle for mapping from kva/uva/physical 452 * address space into bus device space. 453 */ 454 int 455 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 456 { 457 if (map != NULL && map != &nobounce_dmamap) { 458 if (STAILQ_FIRST(&map->bpages) != NULL) { 459 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 460 __func__, dmat, EBUSY); 461 return (EBUSY); 462 } 463 free(map, M_DEVBUF); 464 } 465 dmat->map_count--; 466 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat); 467 return (0); 468 } 469 470 471 /* 472 * Allocate a piece of memory that can be efficiently mapped into 473 * bus device space based on the constraints lited in the dma tag. 474 * A dmamap to for use with dmamap_load is also allocated. 475 */ 476 int 477 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 478 bus_dmamap_t *mapp) 479 { 480 int mflags; 481 482 if (flags & BUS_DMA_NOWAIT) 483 mflags = M_NOWAIT; 484 else 485 mflags = M_WAITOK; 486 if (flags & BUS_DMA_ZERO) 487 mflags |= M_ZERO; 488 489 /* If we succeed, no mapping/bouncing will be required */ 490 *mapp = NULL; 491 492 if (dmat->segments == NULL) { 493 dmat->segments = (bus_dma_segment_t *)malloc( 494 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 495 M_NOWAIT); 496 if (dmat->segments == NULL) { 497 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 498 __func__, dmat, dmat->flags, ENOMEM); 499 return (ENOMEM); 500 } 501 } 502 503 /* 504 * XXX: 505 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact 506 * alignment guarantees of malloc need to be nailed down, and the 507 * code below should be rewritten to take that into account. 508 * 509 * In the meantime, we'll warn the user if malloc gets it wrong. 510 */ 511 if ((dmat->maxsize <= PAGE_SIZE) && 512 (dmat->alignment < dmat->maxsize) && 513 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 514 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags); 515 } else { 516 /* 517 * XXX Use Contigmalloc until it is merged into this facility 518 * and handles multi-seg allocations. Nobody is doing 519 * multi-seg allocations yet though. 520 * XXX Certain AGP hardware does. 521 */ 522 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags, 523 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 524 dmat->boundary); 525 } 526 if (*vaddr == NULL) { 527 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 528 __func__, dmat, dmat->flags, ENOMEM); 529 return (ENOMEM); 530 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) { 531 printf("bus_dmamem_alloc failed to align memory properly.\n"); 532 } 533 if (flags & BUS_DMA_NOCACHE) 534 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize, 535 PAT_UNCACHEABLE); 536 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 537 __func__, dmat, dmat->flags, ENOMEM); 538 return (0); 539 } 540 541 /* 542 * Free a piece of memory and it's allociated dmamap, that was allocated 543 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 544 */ 545 void 546 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 547 { 548 /* 549 * dmamem does not need to be bounced, so the map should be 550 * NULL 551 */ 552 if (map != NULL) 553 panic("bus_dmamem_free: Invalid map freed\n"); 554 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK); 555 if ((dmat->maxsize <= PAGE_SIZE) && 556 (dmat->alignment < dmat->maxsize) && 557 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 558 free(vaddr, M_DEVBUF); 559 else { 560 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 561 } 562 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags); 563 } 564 565 /* 566 * Utility function to load a linear buffer. lastaddrp holds state 567 * between invocations (for multiple-buffer loads). segp contains 568 * the starting segment on entrace, and the ending segment on exit. 569 * first indicates if this is the first invocation of this function. 570 */ 571 static __inline int 572 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, 573 bus_dmamap_t map, 574 void *buf, bus_size_t buflen, 575 pmap_t pmap, 576 int flags, 577 bus_addr_t *lastaddrp, 578 bus_dma_segment_t *segs, 579 int *segp, 580 int first) 581 { 582 bus_size_t sgsize; 583 bus_addr_t curaddr, lastaddr, baddr, bmask; 584 vm_offset_t vaddr; 585 bus_addr_t paddr; 586 int seg; 587 588 if (map == NULL) 589 map = &nobounce_dmamap; 590 591 if ((map != &nobounce_dmamap && map->pagesneeded == 0) 592 && ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0)) { 593 vm_offset_t vendaddr; 594 595 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, " 596 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem), 597 dmat->boundary, dmat->alignment); 598 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d", 599 map, &nobounce_dmamap, map->pagesneeded); 600 /* 601 * Count the number of bounce pages 602 * needed in order to complete this transfer 603 */ 604 vaddr = (vm_offset_t)buf; 605 vendaddr = (vm_offset_t)buf + buflen; 606 607 while (vaddr < vendaddr) { 608 if (pmap) 609 paddr = pmap_extract(pmap, vaddr); 610 else 611 paddr = pmap_kextract(vaddr); 612 if (run_filter(dmat, paddr) != 0) 613 map->pagesneeded++; 614 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK)); 615 } 616 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded); 617 } 618 619 /* Reserve Necessary Bounce Pages */ 620 if (map->pagesneeded != 0) { 621 mtx_lock(&bounce_lock); 622 if (flags & BUS_DMA_NOWAIT) { 623 if (reserve_bounce_pages(dmat, map, 0) != 0) { 624 mtx_unlock(&bounce_lock); 625 return (ENOMEM); 626 } 627 } else { 628 if (reserve_bounce_pages(dmat, map, 1) != 0) { 629 /* Queue us for resources */ 630 map->dmat = dmat; 631 map->buf = buf; 632 map->buflen = buflen; 633 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 634 map, links); 635 mtx_unlock(&bounce_lock); 636 return (EINPROGRESS); 637 } 638 } 639 mtx_unlock(&bounce_lock); 640 } 641 642 vaddr = (vm_offset_t)buf; 643 lastaddr = *lastaddrp; 644 bmask = ~(dmat->boundary - 1); 645 646 for (seg = *segp; buflen > 0 ; ) { 647 /* 648 * Get the physical address for this segment. 649 */ 650 if (pmap) 651 curaddr = pmap_extract(pmap, vaddr); 652 else 653 curaddr = pmap_kextract(vaddr); 654 655 /* 656 * Compute the segment size, and adjust counts. 657 */ 658 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK); 659 if (sgsize > dmat->maxsegsz) 660 sgsize = dmat->maxsegsz; 661 if (buflen < sgsize) 662 sgsize = buflen; 663 664 /* 665 * Make sure we don't cross any boundaries. 666 */ 667 if (dmat->boundary > 0) { 668 baddr = (curaddr + dmat->boundary) & bmask; 669 if (sgsize > (baddr - curaddr)) 670 sgsize = (baddr - curaddr); 671 } 672 673 if (map->pagesneeded != 0 && run_filter(dmat, curaddr)) 674 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 675 676 /* 677 * Insert chunk into a segment, coalescing with 678 * previous segment if possible. 679 */ 680 if (first) { 681 segs[seg].ds_addr = curaddr; 682 segs[seg].ds_len = sgsize; 683 first = 0; 684 } else { 685 if (curaddr == lastaddr && 686 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 687 (dmat->boundary == 0 || 688 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 689 segs[seg].ds_len += sgsize; 690 else { 691 if (++seg >= dmat->nsegments) 692 break; 693 segs[seg].ds_addr = curaddr; 694 segs[seg].ds_len = sgsize; 695 } 696 } 697 698 lastaddr = curaddr + sgsize; 699 vaddr += sgsize; 700 buflen -= sgsize; 701 } 702 703 *segp = seg; 704 *lastaddrp = lastaddr; 705 706 /* 707 * Did we fit? 708 */ 709 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 710 } 711 712 /* 713 * Map the buffer buf into bus space using the dmamap map. 714 */ 715 int 716 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 717 bus_size_t buflen, bus_dmamap_callback_t *callback, 718 void *callback_arg, int flags) 719 { 720 bus_addr_t lastaddr = 0; 721 int error, nsegs = 0; 722 723 if (map != NULL) { 724 flags |= BUS_DMA_WAITOK; 725 map->callback = callback; 726 map->callback_arg = callback_arg; 727 } 728 729 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags, 730 &lastaddr, dmat->segments, &nsegs, 1); 731 732 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 733 __func__, dmat, dmat->flags, error, nsegs + 1); 734 735 if (error == EINPROGRESS) { 736 return (error); 737 } 738 739 if (error) 740 (*callback)(callback_arg, dmat->segments, 0, error); 741 else 742 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0); 743 744 /* 745 * Return ENOMEM to the caller so that it can pass it up the stack. 746 * This error only happens when NOWAIT is set, so deferal is disabled. 747 */ 748 if (error == ENOMEM) 749 return (error); 750 751 return (0); 752 } 753 754 755 /* 756 * Like _bus_dmamap_load(), but for mbufs. 757 */ 758 int 759 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 760 struct mbuf *m0, 761 bus_dmamap_callback2_t *callback, void *callback_arg, 762 int flags) 763 { 764 int nsegs, error; 765 766 M_ASSERTPKTHDR(m0); 767 768 flags |= BUS_DMA_NOWAIT; 769 nsegs = 0; 770 error = 0; 771 if (m0->m_pkthdr.len <= dmat->maxsize) { 772 int first = 1; 773 bus_addr_t lastaddr = 0; 774 struct mbuf *m; 775 776 for (m = m0; m != NULL && error == 0; m = m->m_next) { 777 if (m->m_len > 0) { 778 error = _bus_dmamap_load_buffer(dmat, map, 779 m->m_data, m->m_len, 780 NULL, flags, &lastaddr, 781 dmat->segments, &nsegs, first); 782 first = 0; 783 } 784 } 785 } else { 786 error = EINVAL; 787 } 788 789 if (error) { 790 /* force "no valid mappings" in callback */ 791 (*callback)(callback_arg, dmat->segments, 0, 0, error); 792 } else { 793 (*callback)(callback_arg, dmat->segments, 794 nsegs+1, m0->m_pkthdr.len, error); 795 } 796 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 797 __func__, dmat, dmat->flags, error, nsegs + 1); 798 return (error); 799 } 800 801 int 802 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 803 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 804 int flags) 805 { 806 int error; 807 808 M_ASSERTPKTHDR(m0); 809 810 flags |= BUS_DMA_NOWAIT; 811 *nsegs = 0; 812 error = 0; 813 if (m0->m_pkthdr.len <= dmat->maxsize) { 814 int first = 1; 815 bus_addr_t lastaddr = 0; 816 struct mbuf *m; 817 818 for (m = m0; m != NULL && error == 0; m = m->m_next) { 819 if (m->m_len > 0) { 820 error = _bus_dmamap_load_buffer(dmat, map, 821 m->m_data, m->m_len, 822 NULL, flags, &lastaddr, 823 segs, nsegs, first); 824 first = 0; 825 } 826 } 827 } else { 828 error = EINVAL; 829 } 830 831 /* XXX FIXME: Having to increment nsegs is really annoying */ 832 ++*nsegs; 833 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 834 __func__, dmat, dmat->flags, error, *nsegs); 835 return (error); 836 } 837 838 /* 839 * Like _bus_dmamap_load(), but for uios. 840 */ 841 int 842 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 843 struct uio *uio, 844 bus_dmamap_callback2_t *callback, void *callback_arg, 845 int flags) 846 { 847 bus_addr_t lastaddr = 0; 848 int nsegs, error, first, i; 849 bus_size_t resid; 850 struct iovec *iov; 851 pmap_t pmap; 852 853 flags |= BUS_DMA_NOWAIT; 854 resid = uio->uio_resid; 855 iov = uio->uio_iov; 856 857 if (uio->uio_segflg == UIO_USERSPACE) { 858 KASSERT(uio->uio_td != NULL, 859 ("bus_dmamap_load_uio: USERSPACE but no proc")); 860 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace); 861 } else 862 pmap = NULL; 863 864 nsegs = 0; 865 error = 0; 866 first = 1; 867 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 868 /* 869 * Now at the first iovec to load. Load each iovec 870 * until we have exhausted the residual count. 871 */ 872 bus_size_t minlen = 873 resid < iov[i].iov_len ? resid : iov[i].iov_len; 874 caddr_t addr = (caddr_t) iov[i].iov_base; 875 876 if (minlen > 0) { 877 error = _bus_dmamap_load_buffer(dmat, map, 878 addr, minlen, pmap, flags, &lastaddr, 879 dmat->segments, &nsegs, first); 880 first = 0; 881 882 resid -= minlen; 883 } 884 } 885 886 if (error) { 887 /* force "no valid mappings" in callback */ 888 (*callback)(callback_arg, dmat->segments, 0, 0, error); 889 } else { 890 (*callback)(callback_arg, dmat->segments, 891 nsegs+1, uio->uio_resid, error); 892 } 893 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 894 __func__, dmat, dmat->flags, error, nsegs + 1); 895 return (error); 896 } 897 898 /* 899 * Release the mapping held by map. 900 */ 901 void 902 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 903 { 904 struct bounce_page *bpage; 905 906 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 907 STAILQ_REMOVE_HEAD(&map->bpages, links); 908 free_bounce_page(dmat, bpage); 909 } 910 } 911 912 void 913 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 914 { 915 struct bounce_page *bpage; 916 917 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 918 /* 919 * Handle data bouncing. We might also 920 * want to add support for invalidating 921 * the caches on broken hardware 922 */ 923 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x " 924 "performing bounce", __func__, op, dmat, dmat->flags); 925 926 if (op & BUS_DMASYNC_PREWRITE) { 927 while (bpage != NULL) { 928 bcopy((void *)bpage->datavaddr, 929 (void *)bpage->vaddr, 930 bpage->datacount); 931 bpage = STAILQ_NEXT(bpage, links); 932 } 933 dmat->bounce_zone->total_bounced++; 934 } 935 936 if (op & BUS_DMASYNC_POSTREAD) { 937 while (bpage != NULL) { 938 bcopy((void *)bpage->vaddr, 939 (void *)bpage->datavaddr, 940 bpage->datacount); 941 bpage = STAILQ_NEXT(bpage, links); 942 } 943 dmat->bounce_zone->total_bounced++; 944 } 945 } 946 } 947 948 static void 949 init_bounce_pages(void *dummy __unused) 950 { 951 952 total_bpages = 0; 953 STAILQ_INIT(&bounce_zone_list); 954 STAILQ_INIT(&bounce_map_waitinglist); 955 STAILQ_INIT(&bounce_map_callbacklist); 956 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 957 } 958 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 959 960 static struct sysctl_ctx_list * 961 busdma_sysctl_tree(struct bounce_zone *bz) 962 { 963 return (&bz->sysctl_tree); 964 } 965 966 static struct sysctl_oid * 967 busdma_sysctl_tree_top(struct bounce_zone *bz) 968 { 969 return (bz->sysctl_tree_top); 970 } 971 972 static int 973 alloc_bounce_zone(bus_dma_tag_t dmat) 974 { 975 struct bounce_zone *bz; 976 977 /* Check to see if we already have a suitable zone */ 978 STAILQ_FOREACH(bz, &bounce_zone_list, links) { 979 if ((dmat->alignment <= bz->alignment) 980 && (dmat->lowaddr >= bz->lowaddr)) { 981 dmat->bounce_zone = bz; 982 return (0); 983 } 984 } 985 986 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF, 987 M_NOWAIT | M_ZERO)) == NULL) 988 return (ENOMEM); 989 990 STAILQ_INIT(&bz->bounce_page_list); 991 bz->free_bpages = 0; 992 bz->reserved_bpages = 0; 993 bz->active_bpages = 0; 994 bz->lowaddr = dmat->lowaddr; 995 bz->alignment = MAX(dmat->alignment, PAGE_SIZE); 996 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount); 997 busdma_zonecount++; 998 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr); 999 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links); 1000 dmat->bounce_zone = bz; 1001 1002 sysctl_ctx_init(&bz->sysctl_tree); 1003 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree, 1004 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid, 1005 CTLFLAG_RD, 0, ""); 1006 if (bz->sysctl_tree_top == NULL) { 1007 sysctl_ctx_free(&bz->sysctl_tree); 1008 return (0); /* XXX error code? */ 1009 } 1010 1011 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1012 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1013 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0, 1014 "Total bounce pages"); 1015 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1016 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1017 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0, 1018 "Free bounce pages"); 1019 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1020 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1021 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0, 1022 "Reserved bounce pages"); 1023 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1024 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1025 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0, 1026 "Active bounce pages"); 1027 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1028 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1029 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0, 1030 "Total bounce requests"); 1031 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1032 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1033 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0, 1034 "Total bounce requests that were deferred"); 1035 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz), 1036 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1037 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, ""); 1038 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1039 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1040 "alignment", CTLFLAG_RD, &bz->alignment, 0, ""); 1041 1042 return (0); 1043 } 1044 1045 static int 1046 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 1047 { 1048 struct bounce_zone *bz; 1049 int count; 1050 1051 bz = dmat->bounce_zone; 1052 count = 0; 1053 while (numpages > 0) { 1054 struct bounce_page *bpage; 1055 1056 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 1057 M_NOWAIT | M_ZERO); 1058 1059 if (bpage == NULL) 1060 break; 1061 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 1062 M_NOWAIT, 0ul, 1063 bz->lowaddr, 1064 PAGE_SIZE, 1065 0); 1066 if (bpage->vaddr == 0) { 1067 free(bpage, M_DEVBUF); 1068 break; 1069 } 1070 bpage->busaddr = pmap_kextract(bpage->vaddr); 1071 mtx_lock(&bounce_lock); 1072 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links); 1073 total_bpages++; 1074 bz->total_bpages++; 1075 bz->free_bpages++; 1076 mtx_unlock(&bounce_lock); 1077 count++; 1078 numpages--; 1079 } 1080 return (count); 1081 } 1082 1083 static int 1084 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 1085 { 1086 struct bounce_zone *bz; 1087 int pages; 1088 1089 mtx_assert(&bounce_lock, MA_OWNED); 1090 bz = dmat->bounce_zone; 1091 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved); 1092 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 1093 return (map->pagesneeded - (map->pagesreserved + pages)); 1094 bz->free_bpages -= pages; 1095 bz->reserved_bpages += pages; 1096 map->pagesreserved += pages; 1097 pages = map->pagesneeded - map->pagesreserved; 1098 1099 return (pages); 1100 } 1101 1102 static bus_addr_t 1103 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 1104 bus_size_t size) 1105 { 1106 struct bounce_zone *bz; 1107 struct bounce_page *bpage; 1108 1109 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag")); 1110 KASSERT(map != NULL && map != &nobounce_dmamap, 1111 ("add_bounce_page: bad map %p", map)); 1112 1113 bz = dmat->bounce_zone; 1114 if (map->pagesneeded == 0) 1115 panic("add_bounce_page: map doesn't need any pages"); 1116 map->pagesneeded--; 1117 1118 if (map->pagesreserved == 0) 1119 panic("add_bounce_page: map doesn't need any pages"); 1120 map->pagesreserved--; 1121 1122 mtx_lock(&bounce_lock); 1123 bpage = STAILQ_FIRST(&bz->bounce_page_list); 1124 if (bpage == NULL) 1125 panic("add_bounce_page: free page list is empty"); 1126 1127 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links); 1128 bz->reserved_bpages--; 1129 bz->active_bpages++; 1130 mtx_unlock(&bounce_lock); 1131 1132 bpage->datavaddr = vaddr; 1133 bpage->datacount = size; 1134 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 1135 return (bpage->busaddr); 1136 } 1137 1138 static void 1139 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 1140 { 1141 struct bus_dmamap *map; 1142 struct bounce_zone *bz; 1143 1144 bz = dmat->bounce_zone; 1145 bpage->datavaddr = 0; 1146 bpage->datacount = 0; 1147 1148 mtx_lock(&bounce_lock); 1149 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links); 1150 bz->free_bpages++; 1151 bz->active_bpages--; 1152 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 1153 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 1154 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 1155 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 1156 map, links); 1157 busdma_swi_pending = 1; 1158 bz->total_deferred++; 1159 swi_sched(vm_ih, 0); 1160 } 1161 } 1162 mtx_unlock(&bounce_lock); 1163 } 1164 1165 void 1166 busdma_swi(void) 1167 { 1168 bus_dma_tag_t dmat; 1169 struct bus_dmamap *map; 1170 1171 mtx_lock(&bounce_lock); 1172 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 1173 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 1174 mtx_unlock(&bounce_lock); 1175 dmat = map->dmat; 1176 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK); 1177 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 1178 map->callback, map->callback_arg, /*flags*/0); 1179 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK); 1180 mtx_lock(&bounce_lock); 1181 } 1182 mtx_unlock(&bounce_lock); 1183 }
Cache object: db52a4753dbb95e32249755d3a10d88d
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