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_size_t boundary; 98 bus_addr_t lowaddr; 99 char zoneid[8]; 100 char lowaddrid[20]; 101 struct sysctl_ctx_list sysctl_tree; 102 struct sysctl_oid *sysctl_tree_top; 103 }; 104 105 static struct mtx bounce_lock; 106 static int total_bpages; 107 static int busdma_zonecount; 108 static STAILQ_HEAD(, bounce_zone) bounce_zone_list; 109 110 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters"); 111 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0, 112 "Total bounce pages"); 113 114 struct bus_dmamap { 115 struct bp_list bpages; 116 int pagesneeded; 117 int pagesreserved; 118 bus_dma_tag_t dmat; 119 void *buf; /* unmapped buffer pointer */ 120 bus_size_t buflen; /* unmapped buffer length */ 121 bus_dmamap_callback_t *callback; 122 void *callback_arg; 123 STAILQ_ENTRY(bus_dmamap) links; 124 }; 125 126 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 127 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 128 static struct bus_dmamap nobounce_dmamap; 129 130 static void init_bounce_pages(void *dummy); 131 static int alloc_bounce_zone(bus_dma_tag_t dmat); 132 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 133 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, 134 int commit); 135 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 136 vm_offset_t vaddr, bus_size_t size); 137 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 138 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 139 140 /* 141 * Return true if a match is made. 142 * 143 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 144 * 145 * If paddr is within the bounds of the dma tag then call the filter callback 146 * to check for a match, if there is no filter callback then assume a match. 147 */ 148 static __inline int 149 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 150 { 151 int retval; 152 153 retval = 0; 154 155 do { 156 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) 157 || ((paddr & (dmat->alignment - 1)) != 0)) 158 && (dmat->filter == NULL 159 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 160 retval = 1; 161 162 dmat = dmat->parent; 163 } while (retval == 0 && dmat != NULL); 164 return (retval); 165 } 166 167 /* 168 * Convenience function for manipulating driver locks from busdma (during 169 * busdma_swi, for example). Drivers that don't provide their own locks 170 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own 171 * non-mutex locking scheme don't have to use this at all. 172 */ 173 void 174 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op) 175 { 176 struct mtx *dmtx; 177 178 dmtx = (struct mtx *)arg; 179 switch (op) { 180 case BUS_DMA_LOCK: 181 mtx_lock(dmtx); 182 break; 183 case BUS_DMA_UNLOCK: 184 mtx_unlock(dmtx); 185 break; 186 default: 187 panic("Unknown operation 0x%x for busdma_lock_mutex!", op); 188 } 189 } 190 191 /* 192 * dflt_lock should never get called. It gets put into the dma tag when 193 * lockfunc == NULL, which is only valid if the maps that are associated 194 * with the tag are meant to never be defered. 195 * XXX Should have a way to identify which driver is responsible here. 196 */ 197 static void 198 dflt_lock(void *arg, bus_dma_lock_op_t op) 199 { 200 panic("driver error: busdma dflt_lock called"); 201 } 202 203 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3 204 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 205 /* 206 * Allocate a device specific dma_tag. 207 */ 208 int 209 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 210 bus_size_t boundary, bus_addr_t lowaddr, 211 bus_addr_t highaddr, bus_dma_filter_t *filter, 212 void *filterarg, bus_size_t maxsize, int nsegments, 213 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc, 214 void *lockfuncarg, bus_dma_tag_t *dmat) 215 { 216 bus_dma_tag_t newtag; 217 int error = 0; 218 219 /* Always enforce at least a 4GB boundary. */ 220 if (boundary == 0 || boundary > ((bus_addr_t)1 << 32)) 221 boundary = (bus_size_t)1 << 32; 222 223 /* Basic sanity checking */ 224 if (boundary != 0 && boundary < maxsegsz) 225 maxsegsz = boundary; 226 227 /* Return a NULL tag on failure */ 228 *dmat = NULL; 229 230 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, 231 M_ZERO | M_NOWAIT); 232 if (newtag == NULL) { 233 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 234 __func__, newtag, 0, error); 235 return (ENOMEM); 236 } 237 238 newtag->parent = parent; 239 newtag->alignment = alignment; 240 newtag->boundary = boundary; 241 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 242 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + 243 (PAGE_SIZE - 1); 244 newtag->filter = filter; 245 newtag->filterarg = filterarg; 246 newtag->maxsize = maxsize; 247 newtag->nsegments = nsegments; 248 newtag->maxsegsz = maxsegsz; 249 newtag->flags = flags; 250 newtag->ref_count = 1; /* Count ourself */ 251 newtag->map_count = 0; 252 if (lockfunc != NULL) { 253 newtag->lockfunc = lockfunc; 254 newtag->lockfuncarg = lockfuncarg; 255 } else { 256 newtag->lockfunc = dflt_lock; 257 newtag->lockfuncarg = NULL; 258 } 259 newtag->segments = NULL; 260 261 /* Take into account any restrictions imposed by our parent tag */ 262 if (parent != NULL) { 263 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 264 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 265 if (newtag->boundary == 0) 266 newtag->boundary = parent->boundary; 267 else if (parent->boundary != 0) 268 newtag->boundary = MIN(parent->boundary, 269 newtag->boundary); 270 if (newtag->filter == NULL) { 271 /* 272 * Short circuit looking at our parent directly 273 * since we have encapsulated all of its information 274 */ 275 newtag->filter = parent->filter; 276 newtag->filterarg = parent->filterarg; 277 newtag->parent = parent->parent; 278 } 279 if (newtag->parent != NULL) 280 atomic_add_int(&parent->ref_count, 1); 281 } 282 283 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) 284 || newtag->alignment > 1) 285 newtag->flags |= BUS_DMA_COULD_BOUNCE; 286 287 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) && 288 (flags & BUS_DMA_ALLOCNOW) != 0) { 289 struct bounce_zone *bz; 290 291 /* Must bounce */ 292 293 if ((error = alloc_bounce_zone(newtag)) != 0) { 294 free(newtag, M_DEVBUF); 295 return (error); 296 } 297 bz = newtag->bounce_zone; 298 299 if (ptoa(bz->total_bpages) < maxsize) { 300 int pages; 301 302 pages = atop(maxsize) - bz->total_bpages; 303 304 /* Add pages to our bounce pool */ 305 if (alloc_bounce_pages(newtag, pages) < pages) 306 error = ENOMEM; 307 } 308 /* Performed initial allocation */ 309 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 310 } 311 312 if (error != 0) { 313 free(newtag, M_DEVBUF); 314 } else { 315 *dmat = newtag; 316 } 317 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 318 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error); 319 return (error); 320 } 321 322 int 323 bus_dma_tag_destroy(bus_dma_tag_t dmat) 324 { 325 bus_dma_tag_t dmat_copy; 326 int error; 327 328 error = 0; 329 dmat_copy = dmat; 330 331 if (dmat != NULL) { 332 333 if (dmat->map_count != 0) { 334 error = EBUSY; 335 goto out; 336 } 337 338 while (dmat != NULL) { 339 bus_dma_tag_t parent; 340 341 parent = dmat->parent; 342 atomic_subtract_int(&dmat->ref_count, 1); 343 if (dmat->ref_count == 0) { 344 if (dmat->segments != NULL) 345 free(dmat->segments, M_DEVBUF); 346 free(dmat, M_DEVBUF); 347 /* 348 * Last reference count, so 349 * release our reference 350 * count on our parent. 351 */ 352 dmat = parent; 353 } else 354 dmat = NULL; 355 } 356 } 357 out: 358 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error); 359 return (error); 360 } 361 362 /* 363 * Allocate a handle for mapping from kva/uva/physical 364 * address space into bus device space. 365 */ 366 int 367 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 368 { 369 int error; 370 371 error = 0; 372 373 if (dmat->segments == NULL) { 374 dmat->segments = (bus_dma_segment_t *)malloc( 375 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 376 M_NOWAIT); 377 if (dmat->segments == NULL) { 378 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 379 __func__, dmat, ENOMEM); 380 return (ENOMEM); 381 } 382 } 383 384 /* 385 * Bouncing might be required if the driver asks for an active 386 * exclusion region, a data alignment that is stricter than 1, and/or 387 * an active address boundary. 388 */ 389 if (dmat->flags & BUS_DMA_COULD_BOUNCE) { 390 391 /* Must bounce */ 392 struct bounce_zone *bz; 393 int maxpages; 394 395 if (dmat->bounce_zone == NULL) { 396 if ((error = alloc_bounce_zone(dmat)) != 0) 397 return (error); 398 } 399 bz = dmat->bounce_zone; 400 401 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 402 M_NOWAIT | M_ZERO); 403 if (*mapp == NULL) { 404 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 405 __func__, dmat, ENOMEM); 406 return (ENOMEM); 407 } 408 409 /* Initialize the new map */ 410 STAILQ_INIT(&((*mapp)->bpages)); 411 412 /* 413 * Attempt to add pages to our pool on a per-instance 414 * basis up to a sane limit. 415 */ 416 if (dmat->alignment > 1) 417 maxpages = MAX_BPAGES; 418 else 419 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr)); 420 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 421 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) { 422 int pages; 423 424 pages = MAX(atop(dmat->maxsize), 1); 425 pages = MIN(maxpages - bz->total_bpages, pages); 426 pages = MAX(pages, 1); 427 if (alloc_bounce_pages(dmat, pages) < pages) 428 error = ENOMEM; 429 430 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 431 if (error == 0) 432 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 433 } else { 434 error = 0; 435 } 436 } 437 } else { 438 *mapp = NULL; 439 } 440 if (error == 0) 441 dmat->map_count++; 442 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 443 __func__, dmat, dmat->flags, error); 444 return (error); 445 } 446 447 /* 448 * Destroy a handle for mapping from kva/uva/physical 449 * address space into bus device space. 450 */ 451 int 452 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 453 { 454 if (map != NULL && map != &nobounce_dmamap) { 455 if (STAILQ_FIRST(&map->bpages) != NULL) { 456 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 457 __func__, dmat, EBUSY); 458 return (EBUSY); 459 } 460 free(map, M_DEVBUF); 461 } 462 dmat->map_count--; 463 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat); 464 return (0); 465 } 466 467 468 /* 469 * Allocate a piece of memory that can be efficiently mapped into 470 * bus device space based on the constraints lited in the dma tag. 471 * A dmamap to for use with dmamap_load is also allocated. 472 */ 473 int 474 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 475 bus_dmamap_t *mapp) 476 { 477 int mflags; 478 479 if (flags & BUS_DMA_NOWAIT) 480 mflags = M_NOWAIT; 481 else 482 mflags = M_WAITOK; 483 if (flags & BUS_DMA_ZERO) 484 mflags |= M_ZERO; 485 486 /* If we succeed, no mapping/bouncing will be required */ 487 *mapp = NULL; 488 489 if (dmat->segments == NULL) { 490 dmat->segments = (bus_dma_segment_t *)malloc( 491 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 492 M_NOWAIT); 493 if (dmat->segments == NULL) { 494 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 495 __func__, dmat, dmat->flags, ENOMEM); 496 return (ENOMEM); 497 } 498 } 499 500 /* 501 * XXX: 502 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact 503 * alignment guarantees of malloc need to be nailed down, and the 504 * code below should be rewritten to take that into account. 505 * 506 * In the meantime, we'll warn the user if malloc gets it wrong. 507 */ 508 if ((dmat->maxsize <= PAGE_SIZE) && 509 (dmat->alignment < dmat->maxsize) && 510 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 511 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags); 512 } else { 513 /* 514 * XXX Use Contigmalloc until it is merged into this facility 515 * and handles multi-seg allocations. Nobody is doing 516 * multi-seg allocations yet though. 517 * XXX Certain AGP hardware does. 518 */ 519 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags, 520 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 521 dmat->boundary); 522 } 523 if (*vaddr == NULL) { 524 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 525 __func__, dmat, dmat->flags, ENOMEM); 526 return (ENOMEM); 527 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) { 528 printf("bus_dmamem_alloc failed to align memory properly.\n"); 529 } 530 if (flags & BUS_DMA_NOCACHE) 531 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize, 532 PAT_UNCACHEABLE); 533 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 534 __func__, dmat, dmat->flags, ENOMEM); 535 return (0); 536 } 537 538 /* 539 * Free a piece of memory and it's allociated dmamap, that was allocated 540 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 541 */ 542 void 543 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 544 { 545 /* 546 * dmamem does not need to be bounced, so the map should be 547 * NULL 548 */ 549 if (map != NULL) 550 panic("bus_dmamem_free: Invalid map freed\n"); 551 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK); 552 if ((dmat->maxsize <= PAGE_SIZE) && 553 (dmat->alignment < dmat->maxsize) && 554 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 555 free(vaddr, M_DEVBUF); 556 else { 557 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 558 } 559 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags); 560 } 561 562 /* 563 * Utility function to load a linear buffer. lastaddrp holds state 564 * between invocations (for multiple-buffer loads). segp contains 565 * the starting segment on entrace, and the ending segment on exit. 566 * first indicates if this is the first invocation of this function. 567 */ 568 static __inline int 569 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, 570 bus_dmamap_t map, 571 void *buf, bus_size_t buflen, 572 pmap_t pmap, 573 int flags, 574 bus_addr_t *lastaddrp, 575 bus_dma_segment_t *segs, 576 int *segp, 577 int first) 578 { 579 bus_size_t sgsize; 580 bus_addr_t curaddr, lastaddr, baddr, bmask; 581 vm_offset_t vaddr; 582 bus_addr_t paddr; 583 int seg; 584 585 if (map == NULL) 586 map = &nobounce_dmamap; 587 588 if ((map != &nobounce_dmamap && map->pagesneeded == 0) 589 && ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0)) { 590 vm_offset_t vendaddr; 591 592 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, " 593 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem), 594 dmat->boundary, dmat->alignment); 595 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d", 596 map, &nobounce_dmamap, map->pagesneeded); 597 /* 598 * Count the number of bounce pages 599 * needed in order to complete this transfer 600 */ 601 vaddr = (vm_offset_t)buf; 602 vendaddr = (vm_offset_t)buf + buflen; 603 604 while (vaddr < vendaddr) { 605 paddr = pmap_kextract(vaddr); 606 if (run_filter(dmat, paddr) != 0) 607 map->pagesneeded++; 608 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK)); 609 } 610 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded); 611 } 612 613 /* Reserve Necessary Bounce Pages */ 614 if (map->pagesneeded != 0) { 615 mtx_lock(&bounce_lock); 616 if (flags & BUS_DMA_NOWAIT) { 617 if (reserve_bounce_pages(dmat, map, 0) != 0) { 618 mtx_unlock(&bounce_lock); 619 return (ENOMEM); 620 } 621 } else { 622 if (reserve_bounce_pages(dmat, map, 1) != 0) { 623 /* Queue us for resources */ 624 map->dmat = dmat; 625 map->buf = buf; 626 map->buflen = buflen; 627 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 628 map, links); 629 mtx_unlock(&bounce_lock); 630 return (EINPROGRESS); 631 } 632 } 633 mtx_unlock(&bounce_lock); 634 } 635 636 vaddr = (vm_offset_t)buf; 637 lastaddr = *lastaddrp; 638 bmask = ~(dmat->boundary - 1); 639 640 for (seg = *segp; buflen > 0 ; ) { 641 /* 642 * Get the physical address for this segment. 643 */ 644 if (pmap) 645 curaddr = pmap_extract(pmap, vaddr); 646 else 647 curaddr = pmap_kextract(vaddr); 648 649 /* 650 * Compute the segment size, and adjust counts. 651 */ 652 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK); 653 if (buflen < sgsize) 654 sgsize = buflen; 655 656 /* 657 * Make sure we don't cross any boundaries. 658 */ 659 if (dmat->boundary > 0) { 660 baddr = (curaddr + dmat->boundary) & bmask; 661 if (sgsize > (baddr - curaddr)) 662 sgsize = (baddr - curaddr); 663 } 664 665 if (map->pagesneeded != 0 && run_filter(dmat, curaddr)) 666 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 667 668 /* 669 * Insert chunk into a segment, coalescing with 670 * previous segment if possible. 671 */ 672 if (first) { 673 segs[seg].ds_addr = curaddr; 674 segs[seg].ds_len = sgsize; 675 first = 0; 676 } else { 677 if (curaddr == lastaddr && 678 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 679 (dmat->boundary == 0 || 680 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 681 segs[seg].ds_len += sgsize; 682 else { 683 if (++seg >= dmat->nsegments) 684 break; 685 segs[seg].ds_addr = curaddr; 686 segs[seg].ds_len = sgsize; 687 } 688 } 689 690 lastaddr = curaddr + sgsize; 691 vaddr += sgsize; 692 buflen -= sgsize; 693 } 694 695 *segp = seg; 696 *lastaddrp = lastaddr; 697 698 /* 699 * Did we fit? 700 */ 701 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 702 } 703 704 /* 705 * Map the buffer buf into bus space using the dmamap map. 706 */ 707 int 708 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 709 bus_size_t buflen, bus_dmamap_callback_t *callback, 710 void *callback_arg, int flags) 711 { 712 bus_addr_t lastaddr = 0; 713 int error, nsegs = 0; 714 715 if (map != NULL) { 716 flags |= BUS_DMA_WAITOK; 717 map->callback = callback; 718 map->callback_arg = callback_arg; 719 } 720 721 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags, 722 &lastaddr, dmat->segments, &nsegs, 1); 723 724 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 725 __func__, dmat, dmat->flags, error, nsegs + 1); 726 727 if (error == EINPROGRESS) { 728 return (error); 729 } 730 731 if (error) 732 (*callback)(callback_arg, dmat->segments, 0, error); 733 else 734 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0); 735 736 /* 737 * Return ENOMEM to the caller so that it can pass it up the stack. 738 * This error only happens when NOWAIT is set, so deferal is disabled. 739 */ 740 if (error == ENOMEM) 741 return (error); 742 743 return (0); 744 } 745 746 747 /* 748 * Like _bus_dmamap_load(), but for mbufs. 749 */ 750 int 751 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 752 struct mbuf *m0, 753 bus_dmamap_callback2_t *callback, void *callback_arg, 754 int flags) 755 { 756 int nsegs, error; 757 758 M_ASSERTPKTHDR(m0); 759 760 flags |= BUS_DMA_NOWAIT; 761 nsegs = 0; 762 error = 0; 763 if (m0->m_pkthdr.len <= dmat->maxsize) { 764 int first = 1; 765 bus_addr_t lastaddr = 0; 766 struct mbuf *m; 767 768 for (m = m0; m != NULL && error == 0; m = m->m_next) { 769 if (m->m_len > 0) { 770 error = _bus_dmamap_load_buffer(dmat, map, 771 m->m_data, m->m_len, 772 NULL, flags, &lastaddr, 773 dmat->segments, &nsegs, first); 774 first = 0; 775 } 776 } 777 } else { 778 error = EINVAL; 779 } 780 781 if (error) { 782 /* force "no valid mappings" in callback */ 783 (*callback)(callback_arg, dmat->segments, 0, 0, error); 784 } else { 785 (*callback)(callback_arg, dmat->segments, 786 nsegs+1, m0->m_pkthdr.len, error); 787 } 788 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 789 __func__, dmat, dmat->flags, error, nsegs + 1); 790 return (error); 791 } 792 793 int 794 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 795 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 796 int flags) 797 { 798 int error; 799 800 M_ASSERTPKTHDR(m0); 801 802 flags |= BUS_DMA_NOWAIT; 803 *nsegs = 0; 804 error = 0; 805 if (m0->m_pkthdr.len <= dmat->maxsize) { 806 int first = 1; 807 bus_addr_t lastaddr = 0; 808 struct mbuf *m; 809 810 for (m = m0; m != NULL && error == 0; m = m->m_next) { 811 if (m->m_len > 0) { 812 error = _bus_dmamap_load_buffer(dmat, map, 813 m->m_data, m->m_len, 814 NULL, flags, &lastaddr, 815 segs, nsegs, first); 816 first = 0; 817 } 818 } 819 } else { 820 error = EINVAL; 821 } 822 823 /* XXX FIXME: Having to increment nsegs is really annoying */ 824 ++*nsegs; 825 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 826 __func__, dmat, dmat->flags, error, *nsegs); 827 return (error); 828 } 829 830 /* 831 * Like _bus_dmamap_load(), but for uios. 832 */ 833 int 834 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 835 struct uio *uio, 836 bus_dmamap_callback2_t *callback, void *callback_arg, 837 int flags) 838 { 839 bus_addr_t lastaddr = 0; 840 int nsegs, error, first, i; 841 bus_size_t resid; 842 struct iovec *iov; 843 pmap_t pmap; 844 845 flags |= BUS_DMA_NOWAIT; 846 resid = uio->uio_resid; 847 iov = uio->uio_iov; 848 849 if (uio->uio_segflg == UIO_USERSPACE) { 850 KASSERT(uio->uio_td != NULL, 851 ("bus_dmamap_load_uio: USERSPACE but no proc")); 852 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace); 853 } else 854 pmap = NULL; 855 856 nsegs = 0; 857 error = 0; 858 first = 1; 859 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 860 /* 861 * Now at the first iovec to load. Load each iovec 862 * until we have exhausted the residual count. 863 */ 864 bus_size_t minlen = 865 resid < iov[i].iov_len ? resid : iov[i].iov_len; 866 caddr_t addr = (caddr_t) iov[i].iov_base; 867 868 if (minlen > 0) { 869 error = _bus_dmamap_load_buffer(dmat, map, 870 addr, minlen, pmap, flags, &lastaddr, 871 dmat->segments, &nsegs, first); 872 first = 0; 873 874 resid -= minlen; 875 } 876 } 877 878 if (error) { 879 /* force "no valid mappings" in callback */ 880 (*callback)(callback_arg, dmat->segments, 0, 0, error); 881 } else { 882 (*callback)(callback_arg, dmat->segments, 883 nsegs+1, uio->uio_resid, error); 884 } 885 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 886 __func__, dmat, dmat->flags, error, nsegs + 1); 887 return (error); 888 } 889 890 /* 891 * Release the mapping held by map. 892 */ 893 void 894 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 895 { 896 struct bounce_page *bpage; 897 898 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 899 STAILQ_REMOVE_HEAD(&map->bpages, links); 900 free_bounce_page(dmat, bpage); 901 } 902 } 903 904 void 905 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 906 { 907 struct bounce_page *bpage; 908 909 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 910 /* 911 * Handle data bouncing. We might also 912 * want to add support for invalidating 913 * the caches on broken hardware 914 */ 915 dmat->bounce_zone->total_bounced++; 916 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x " 917 "performing bounce", __func__, op, dmat, dmat->flags); 918 919 if (op & BUS_DMASYNC_PREWRITE) { 920 while (bpage != NULL) { 921 bcopy((void *)bpage->datavaddr, 922 (void *)bpage->vaddr, 923 bpage->datacount); 924 bpage = STAILQ_NEXT(bpage, links); 925 } 926 } 927 928 if (op & BUS_DMASYNC_POSTREAD) { 929 while (bpage != NULL) { 930 bcopy((void *)bpage->vaddr, 931 (void *)bpage->datavaddr, 932 bpage->datacount); 933 bpage = STAILQ_NEXT(bpage, links); 934 } 935 } 936 } 937 } 938 939 static void 940 init_bounce_pages(void *dummy __unused) 941 { 942 943 total_bpages = 0; 944 STAILQ_INIT(&bounce_zone_list); 945 STAILQ_INIT(&bounce_map_waitinglist); 946 STAILQ_INIT(&bounce_map_callbacklist); 947 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 948 } 949 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 950 951 static struct sysctl_ctx_list * 952 busdma_sysctl_tree(struct bounce_zone *bz) 953 { 954 return (&bz->sysctl_tree); 955 } 956 957 static struct sysctl_oid * 958 busdma_sysctl_tree_top(struct bounce_zone *bz) 959 { 960 return (bz->sysctl_tree_top); 961 } 962 963 static int 964 alloc_bounce_zone(bus_dma_tag_t dmat) 965 { 966 struct bounce_zone *bz; 967 968 /* Check to see if we already have a suitable zone */ 969 STAILQ_FOREACH(bz, &bounce_zone_list, links) { 970 if ((dmat->alignment <= bz->alignment) 971 && (dmat->boundary <= bz->boundary) 972 && (dmat->lowaddr >= bz->lowaddr)) { 973 dmat->bounce_zone = bz; 974 return (0); 975 } 976 } 977 978 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF, 979 M_NOWAIT | M_ZERO)) == NULL) 980 return (ENOMEM); 981 982 STAILQ_INIT(&bz->bounce_page_list); 983 bz->free_bpages = 0; 984 bz->reserved_bpages = 0; 985 bz->active_bpages = 0; 986 bz->lowaddr = dmat->lowaddr; 987 bz->alignment = dmat->alignment; 988 bz->boundary = dmat->boundary; 989 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount); 990 busdma_zonecount++; 991 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr); 992 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links); 993 dmat->bounce_zone = bz; 994 995 sysctl_ctx_init(&bz->sysctl_tree); 996 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree, 997 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid, 998 CTLFLAG_RD, 0, ""); 999 if (bz->sysctl_tree_top == NULL) { 1000 sysctl_ctx_free(&bz->sysctl_tree); 1001 return (0); /* XXX error code? */ 1002 } 1003 1004 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1005 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1006 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0, 1007 "Total bounce pages"); 1008 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1009 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1010 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0, 1011 "Free bounce pages"); 1012 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1013 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1014 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0, 1015 "Reserved bounce pages"); 1016 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1017 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1018 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0, 1019 "Active bounce pages"); 1020 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1021 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1022 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0, 1023 "Total bounce requests"); 1024 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1025 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1026 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0, 1027 "Total bounce requests that were deferred"); 1028 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz), 1029 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1030 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, ""); 1031 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1032 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1033 "alignment", CTLFLAG_RD, &bz->alignment, 0, ""); 1034 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1035 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1036 "boundary", CTLFLAG_RD, &bz->boundary, 0, ""); 1037 1038 return (0); 1039 } 1040 1041 static int 1042 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 1043 { 1044 struct bounce_zone *bz; 1045 int count; 1046 1047 bz = dmat->bounce_zone; 1048 count = 0; 1049 while (numpages > 0) { 1050 struct bounce_page *bpage; 1051 1052 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 1053 M_NOWAIT | M_ZERO); 1054 1055 if (bpage == NULL) 1056 break; 1057 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 1058 M_NOWAIT, 0ul, 1059 bz->lowaddr, 1060 PAGE_SIZE, 1061 bz->boundary); 1062 if (bpage->vaddr == 0) { 1063 free(bpage, M_DEVBUF); 1064 break; 1065 } 1066 bpage->busaddr = pmap_kextract(bpage->vaddr); 1067 mtx_lock(&bounce_lock); 1068 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links); 1069 total_bpages++; 1070 bz->total_bpages++; 1071 bz->free_bpages++; 1072 mtx_unlock(&bounce_lock); 1073 count++; 1074 numpages--; 1075 } 1076 return (count); 1077 } 1078 1079 static int 1080 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 1081 { 1082 struct bounce_zone *bz; 1083 int pages; 1084 1085 mtx_assert(&bounce_lock, MA_OWNED); 1086 bz = dmat->bounce_zone; 1087 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved); 1088 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 1089 return (map->pagesneeded - (map->pagesreserved + pages)); 1090 bz->free_bpages -= pages; 1091 bz->reserved_bpages += pages; 1092 map->pagesreserved += pages; 1093 pages = map->pagesneeded - map->pagesreserved; 1094 1095 return (pages); 1096 } 1097 1098 static bus_addr_t 1099 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 1100 bus_size_t size) 1101 { 1102 struct bounce_zone *bz; 1103 struct bounce_page *bpage; 1104 1105 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag")); 1106 KASSERT(map != NULL && map != &nobounce_dmamap, 1107 ("add_bounce_page: bad map %p", map)); 1108 1109 bz = dmat->bounce_zone; 1110 if (map->pagesneeded == 0) 1111 panic("add_bounce_page: map doesn't need any pages"); 1112 map->pagesneeded--; 1113 1114 if (map->pagesreserved == 0) 1115 panic("add_bounce_page: map doesn't need any pages"); 1116 map->pagesreserved--; 1117 1118 mtx_lock(&bounce_lock); 1119 bpage = STAILQ_FIRST(&bz->bounce_page_list); 1120 if (bpage == NULL) 1121 panic("add_bounce_page: free page list is empty"); 1122 1123 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links); 1124 bz->reserved_bpages--; 1125 bz->active_bpages++; 1126 mtx_unlock(&bounce_lock); 1127 1128 bpage->datavaddr = vaddr; 1129 bpage->datacount = size; 1130 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 1131 return (bpage->busaddr); 1132 } 1133 1134 static void 1135 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 1136 { 1137 struct bus_dmamap *map; 1138 struct bounce_zone *bz; 1139 1140 bz = dmat->bounce_zone; 1141 bpage->datavaddr = 0; 1142 bpage->datacount = 0; 1143 1144 mtx_lock(&bounce_lock); 1145 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links); 1146 bz->free_bpages++; 1147 bz->active_bpages--; 1148 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 1149 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 1150 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 1151 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 1152 map, links); 1153 busdma_swi_pending = 1; 1154 bz->total_deferred++; 1155 swi_sched(vm_ih, 0); 1156 } 1157 } 1158 mtx_unlock(&bounce_lock); 1159 } 1160 1161 void 1162 busdma_swi(void) 1163 { 1164 bus_dma_tag_t dmat; 1165 struct bus_dmamap *map; 1166 1167 mtx_lock(&bounce_lock); 1168 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 1169 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 1170 mtx_unlock(&bounce_lock); 1171 dmat = map->dmat; 1172 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK); 1173 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 1174 map->callback, map->callback_arg, /*flags*/0); 1175 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK); 1176 mtx_lock(&bounce_lock); 1177 } 1178 mtx_unlock(&bounce_lock); 1179 }
Cache object: 8d1f0ffa12c4773c26edead913c7699b
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