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 58 struct bounce_zone; 59 60 struct bus_dma_tag { 61 bus_dma_tag_t parent; 62 bus_size_t alignment; 63 bus_size_t boundary; 64 bus_addr_t lowaddr; 65 bus_addr_t highaddr; 66 bus_dma_filter_t *filter; 67 void *filterarg; 68 bus_size_t maxsize; 69 u_int nsegments; 70 bus_size_t maxsegsz; 71 int flags; 72 int ref_count; 73 int map_count; 74 bus_dma_lock_t *lockfunc; 75 void *lockfuncarg; 76 bus_dma_segment_t *segments; 77 struct bounce_zone *bounce_zone; 78 }; 79 80 struct bounce_page { 81 vm_offset_t vaddr; /* kva of bounce buffer */ 82 bus_addr_t busaddr; /* Physical address */ 83 vm_offset_t datavaddr; /* kva of client data */ 84 bus_size_t datacount; /* client data count */ 85 STAILQ_ENTRY(bounce_page) links; 86 }; 87 88 int busdma_swi_pending; 89 90 struct bounce_zone { 91 STAILQ_ENTRY(bounce_zone) links; 92 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 93 int total_bpages; 94 int free_bpages; 95 int reserved_bpages; 96 int active_bpages; 97 int total_bounced; 98 int total_deferred; 99 bus_size_t alignment; 100 bus_size_t boundary; 101 bus_addr_t lowaddr; 102 char zoneid[8]; 103 char lowaddrid[20]; 104 struct sysctl_ctx_list sysctl_tree; 105 struct sysctl_oid *sysctl_tree_top; 106 }; 107 108 static struct mtx bounce_lock; 109 static int total_bpages; 110 static int busdma_zonecount; 111 static STAILQ_HEAD(, bounce_zone) bounce_zone_list; 112 113 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters"); 114 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0, 115 "Total bounce pages"); 116 117 struct bus_dmamap { 118 struct bp_list bpages; 119 int pagesneeded; 120 int pagesreserved; 121 bus_dma_tag_t dmat; 122 void *buf; /* unmapped buffer pointer */ 123 bus_size_t buflen; /* unmapped buffer length */ 124 bus_dmamap_callback_t *callback; 125 void *callback_arg; 126 STAILQ_ENTRY(bus_dmamap) links; 127 }; 128 129 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 130 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 131 static struct bus_dmamap nobounce_dmamap; 132 133 static void init_bounce_pages(void *dummy); 134 static int alloc_bounce_zone(bus_dma_tag_t dmat); 135 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 136 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, 137 int commit); 138 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 139 vm_offset_t vaddr, bus_size_t size); 140 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 141 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 142 143 /* 144 * Return true if a match is made. 145 * 146 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 147 * 148 * If paddr is within the bounds of the dma tag then call the filter callback 149 * to check for a match, if there is no filter callback then assume a match. 150 */ 151 static __inline int 152 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 153 { 154 int retval; 155 156 retval = 0; 157 158 do { 159 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) 160 || ((paddr & (dmat->alignment - 1)) != 0)) 161 && (dmat->filter == NULL 162 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 163 retval = 1; 164 165 dmat = dmat->parent; 166 } while (retval == 0 && dmat != NULL); 167 return (retval); 168 } 169 170 /* 171 * Convenience function for manipulating driver locks from busdma (during 172 * busdma_swi, for example). Drivers that don't provide their own locks 173 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own 174 * non-mutex locking scheme don't have to use this at all. 175 */ 176 void 177 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op) 178 { 179 struct mtx *dmtx; 180 181 dmtx = (struct mtx *)arg; 182 switch (op) { 183 case BUS_DMA_LOCK: 184 mtx_lock(dmtx); 185 break; 186 case BUS_DMA_UNLOCK: 187 mtx_unlock(dmtx); 188 break; 189 default: 190 panic("Unknown operation 0x%x for busdma_lock_mutex!", op); 191 } 192 } 193 194 /* 195 * dflt_lock should never get called. It gets put into the dma tag when 196 * lockfunc == NULL, which is only valid if the maps that are associated 197 * with the tag are meant to never be defered. 198 * XXX Should have a way to identify which driver is responsible here. 199 */ 200 static void 201 dflt_lock(void *arg, bus_dma_lock_op_t op) 202 { 203 panic("driver error: busdma dflt_lock called"); 204 } 205 206 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3 207 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 208 /* 209 * Allocate a device specific dma_tag. 210 */ 211 int 212 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 213 bus_size_t boundary, bus_addr_t lowaddr, 214 bus_addr_t highaddr, bus_dma_filter_t *filter, 215 void *filterarg, bus_size_t maxsize, int nsegments, 216 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc, 217 void *lockfuncarg, bus_dma_tag_t *dmat) 218 { 219 bus_dma_tag_t newtag; 220 int error = 0; 221 222 #if defined(PAE) 223 /* Need at least a 4GB boundary, PAE limitations require 2GB */ 224 if (boundary == 0 || boundary > ((bus_addr_t)1 << 31)) 225 boundary = (bus_size_t)1 << 31; 226 #endif 227 228 /* Basic sanity checking */ 229 if (boundary != 0 && boundary < maxsegsz) 230 maxsegsz = boundary; 231 232 /* Return a NULL tag on failure */ 233 *dmat = NULL; 234 235 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, 236 M_ZERO | M_NOWAIT); 237 if (newtag == NULL) { 238 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 239 __func__, newtag, 0, error); 240 return (ENOMEM); 241 } 242 243 newtag->parent = parent; 244 newtag->alignment = alignment; 245 newtag->boundary = boundary; 246 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 247 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + 248 (PAGE_SIZE - 1); 249 newtag->filter = filter; 250 newtag->filterarg = filterarg; 251 newtag->maxsize = maxsize; 252 newtag->nsegments = nsegments; 253 newtag->maxsegsz = maxsegsz; 254 newtag->flags = flags; 255 newtag->ref_count = 1; /* Count ourself */ 256 newtag->map_count = 0; 257 if (lockfunc != NULL) { 258 newtag->lockfunc = lockfunc; 259 newtag->lockfuncarg = lockfuncarg; 260 } else { 261 newtag->lockfunc = dflt_lock; 262 newtag->lockfuncarg = NULL; 263 } 264 newtag->segments = NULL; 265 266 /* Take into account any restrictions imposed by our parent tag */ 267 if (parent != NULL) { 268 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 269 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 270 if (newtag->boundary == 0) 271 newtag->boundary = parent->boundary; 272 else if (parent->boundary != 0) 273 newtag->boundary = MIN(parent->boundary, 274 newtag->boundary); 275 if (newtag->filter == NULL) { 276 /* 277 * Short circuit looking at our parent directly 278 * since we have encapsulated all of its information 279 */ 280 newtag->filter = parent->filter; 281 newtag->filterarg = parent->filterarg; 282 newtag->parent = parent->parent; 283 } 284 if (newtag->parent != NULL) 285 atomic_add_int(&parent->ref_count, 1); 286 } 287 288 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) 289 || newtag->alignment > 1) 290 newtag->flags |= BUS_DMA_COULD_BOUNCE; 291 292 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) && 293 (flags & BUS_DMA_ALLOCNOW) != 0) { 294 struct bounce_zone *bz; 295 296 /* Must bounce */ 297 298 if ((error = alloc_bounce_zone(newtag)) != 0) { 299 free(newtag, M_DEVBUF); 300 return (error); 301 } 302 bz = newtag->bounce_zone; 303 304 if (ptoa(bz->total_bpages) < maxsize) { 305 int pages; 306 307 pages = atop(maxsize) - bz->total_bpages; 308 309 /* Add pages to our bounce pool */ 310 if (alloc_bounce_pages(newtag, pages) < pages) 311 error = ENOMEM; 312 } 313 /* Performed initial allocation */ 314 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 315 } 316 317 if (error != 0) { 318 free(newtag, M_DEVBUF); 319 } else { 320 *dmat = newtag; 321 } 322 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 323 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error); 324 return (error); 325 } 326 327 int 328 bus_dma_tag_destroy(bus_dma_tag_t dmat) 329 { 330 bus_dma_tag_t dmat_copy; 331 int error; 332 333 error = 0; 334 dmat_copy = dmat; 335 336 if (dmat != NULL) { 337 338 if (dmat->map_count != 0) { 339 error = EBUSY; 340 goto out; 341 } 342 343 while (dmat != NULL) { 344 bus_dma_tag_t parent; 345 346 parent = dmat->parent; 347 atomic_subtract_int(&dmat->ref_count, 1); 348 if (dmat->ref_count == 0) { 349 if (dmat->segments != NULL) 350 free(dmat->segments, M_DEVBUF); 351 free(dmat, M_DEVBUF); 352 /* 353 * Last reference count, so 354 * release our reference 355 * count on our parent. 356 */ 357 dmat = parent; 358 } else 359 dmat = NULL; 360 } 361 } 362 out: 363 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error); 364 return (error); 365 } 366 367 /* 368 * Allocate a handle for mapping from kva/uva/physical 369 * address space into bus device space. 370 */ 371 int 372 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 373 { 374 int error; 375 376 error = 0; 377 378 if (dmat->segments == NULL) { 379 dmat->segments = (bus_dma_segment_t *)malloc( 380 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 381 M_NOWAIT); 382 if (dmat->segments == NULL) { 383 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 384 __func__, dmat, ENOMEM); 385 return (ENOMEM); 386 } 387 } 388 389 /* 390 * Bouncing might be required if the driver asks for an active 391 * exclusion region, a data alignment that is stricter than 1, and/or 392 * an active address boundary. 393 */ 394 if (dmat->flags & BUS_DMA_COULD_BOUNCE) { 395 396 /* Must bounce */ 397 struct bounce_zone *bz; 398 int maxpages; 399 400 if (dmat->bounce_zone == NULL) { 401 if ((error = alloc_bounce_zone(dmat)) != 0) 402 return (error); 403 } 404 bz = dmat->bounce_zone; 405 406 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 407 M_NOWAIT | M_ZERO); 408 if (*mapp == NULL) { 409 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 410 __func__, dmat, ENOMEM); 411 return (ENOMEM); 412 } 413 414 /* Initialize the new map */ 415 STAILQ_INIT(&((*mapp)->bpages)); 416 417 /* 418 * Attempt to add pages to our pool on a per-instance 419 * basis up to a sane limit. 420 */ 421 if (dmat->alignment > 1) 422 maxpages = MAX_BPAGES; 423 else 424 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr)); 425 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 426 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) { 427 int pages; 428 429 pages = MAX(atop(dmat->maxsize), 1); 430 pages = MIN(maxpages - bz->total_bpages, pages); 431 pages = MAX(pages, 1); 432 if (alloc_bounce_pages(dmat, pages) < pages) 433 error = ENOMEM; 434 435 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 436 if (error == 0) 437 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 438 } else { 439 error = 0; 440 } 441 } 442 } else { 443 *mapp = NULL; 444 } 445 if (error == 0) 446 dmat->map_count++; 447 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 448 __func__, dmat, dmat->flags, error); 449 return (error); 450 } 451 452 /* 453 * Destroy a handle for mapping from kva/uva/physical 454 * address space into bus device space. 455 */ 456 int 457 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 458 { 459 if (map != NULL && map != &nobounce_dmamap) { 460 if (STAILQ_FIRST(&map->bpages) != NULL) { 461 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 462 __func__, dmat, EBUSY); 463 return (EBUSY); 464 } 465 free(map, M_DEVBUF); 466 } 467 dmat->map_count--; 468 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat); 469 return (0); 470 } 471 472 473 /* 474 * Allocate a piece of memory that can be efficiently mapped into 475 * bus device space based on the constraints lited in the dma tag. 476 * A dmamap to for use with dmamap_load is also allocated. 477 */ 478 int 479 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 480 bus_dmamap_t *mapp) 481 { 482 int mflags; 483 484 if (flags & BUS_DMA_NOWAIT) 485 mflags = M_NOWAIT; 486 else 487 mflags = M_WAITOK; 488 if (flags & BUS_DMA_ZERO) 489 mflags |= M_ZERO; 490 491 /* If we succeed, no mapping/bouncing will be required */ 492 *mapp = NULL; 493 494 if (dmat->segments == NULL) { 495 dmat->segments = (bus_dma_segment_t *)malloc( 496 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 497 M_NOWAIT); 498 if (dmat->segments == NULL) { 499 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 500 __func__, dmat, dmat->flags, ENOMEM); 501 return (ENOMEM); 502 } 503 } 504 505 /* 506 * XXX: 507 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact 508 * alignment guarantees of malloc need to be nailed down, and the 509 * code below should be rewritten to take that into account. 510 * 511 * In the meantime, we'll warn the user if malloc gets it wrong. 512 */ 513 if ((dmat->maxsize <= PAGE_SIZE) && 514 (dmat->alignment < dmat->maxsize) && 515 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 516 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags); 517 } else { 518 /* 519 * XXX Use Contigmalloc until it is merged into this facility 520 * and handles multi-seg allocations. Nobody is doing 521 * multi-seg allocations yet though. 522 * XXX Certain AGP hardware does. 523 */ 524 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags, 525 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 526 dmat->boundary); 527 } 528 if (*vaddr == NULL) { 529 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 530 __func__, dmat, dmat->flags, ENOMEM); 531 return (ENOMEM); 532 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) { 533 printf("bus_dmamem_alloc failed to align memory properly.\n"); 534 } 535 if (flags & BUS_DMA_NOCACHE) 536 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize, 537 PAT_UNCACHEABLE); 538 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 539 __func__, dmat, dmat->flags, ENOMEM); 540 return (0); 541 } 542 543 /* 544 * Free a piece of memory and it's allociated dmamap, that was allocated 545 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 546 */ 547 void 548 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 549 { 550 /* 551 * dmamem does not need to be bounced, so the map should be 552 * NULL 553 */ 554 if (map != NULL) 555 panic("bus_dmamem_free: Invalid map freed\n"); 556 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK); 557 if ((dmat->maxsize <= PAGE_SIZE) && 558 (dmat->alignment < dmat->maxsize) && 559 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 560 free(vaddr, M_DEVBUF); 561 else { 562 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 563 } 564 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags); 565 } 566 567 /* 568 * Utility function to load a linear buffer. lastaddrp holds state 569 * between invocations (for multiple-buffer loads). segp contains 570 * the starting segment on entrace, and the ending segment on exit. 571 * first indicates if this is the first invocation of this function. 572 */ 573 static __inline int 574 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, 575 bus_dmamap_t map, 576 void *buf, bus_size_t buflen, 577 pmap_t pmap, 578 int flags, 579 bus_addr_t *lastaddrp, 580 bus_dma_segment_t *segs, 581 int *segp, 582 int first) 583 { 584 bus_size_t sgsize; 585 bus_addr_t curaddr, lastaddr, baddr, bmask; 586 vm_offset_t vaddr; 587 bus_addr_t paddr; 588 int seg; 589 590 if (map == NULL) 591 map = &nobounce_dmamap; 592 593 if ((map != &nobounce_dmamap && map->pagesneeded == 0) 594 && ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0)) { 595 vm_offset_t vendaddr; 596 597 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, " 598 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem), 599 dmat->boundary, dmat->alignment); 600 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d", 601 map, &nobounce_dmamap, map->pagesneeded); 602 /* 603 * Count the number of bounce pages 604 * needed in order to complete this transfer 605 */ 606 vaddr = (vm_offset_t)buf; 607 vendaddr = (vm_offset_t)buf + buflen; 608 609 while (vaddr < vendaddr) { 610 paddr = pmap_kextract(vaddr); 611 if (run_filter(dmat, paddr) != 0) 612 map->pagesneeded++; 613 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK)); 614 } 615 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded); 616 } 617 618 /* Reserve Necessary Bounce Pages */ 619 if (map->pagesneeded != 0) { 620 mtx_lock(&bounce_lock); 621 if (flags & BUS_DMA_NOWAIT) { 622 if (reserve_bounce_pages(dmat, map, 0) != 0) { 623 mtx_unlock(&bounce_lock); 624 return (ENOMEM); 625 } 626 } else { 627 if (reserve_bounce_pages(dmat, map, 1) != 0) { 628 /* Queue us for resources */ 629 map->dmat = dmat; 630 map->buf = buf; 631 map->buflen = buflen; 632 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 633 map, links); 634 mtx_unlock(&bounce_lock); 635 return (EINPROGRESS); 636 } 637 } 638 mtx_unlock(&bounce_lock); 639 } 640 641 vaddr = (vm_offset_t)buf; 642 lastaddr = *lastaddrp; 643 bmask = ~(dmat->boundary - 1); 644 645 for (seg = *segp; buflen > 0 ; ) { 646 /* 647 * Get the physical address for this segment. 648 */ 649 if (pmap) 650 curaddr = pmap_extract(pmap, vaddr); 651 else 652 curaddr = pmap_kextract(vaddr); 653 654 /* 655 * Compute the segment size, and adjust counts. 656 */ 657 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK); 658 if (buflen < sgsize) 659 sgsize = buflen; 660 661 /* 662 * Make sure we don't cross any boundaries. 663 */ 664 if (dmat->boundary > 0) { 665 baddr = (curaddr + dmat->boundary) & bmask; 666 if (sgsize > (baddr - curaddr)) 667 sgsize = (baddr - curaddr); 668 } 669 670 if (map->pagesneeded != 0 && run_filter(dmat, curaddr)) 671 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 672 673 /* 674 * Insert chunk into a segment, coalescing with 675 * previous segment if possible. 676 */ 677 if (first) { 678 segs[seg].ds_addr = curaddr; 679 segs[seg].ds_len = sgsize; 680 first = 0; 681 } else { 682 if (curaddr == lastaddr && 683 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 684 (dmat->boundary == 0 || 685 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 686 segs[seg].ds_len += sgsize; 687 else { 688 if (++seg >= dmat->nsegments) 689 break; 690 segs[seg].ds_addr = curaddr; 691 segs[seg].ds_len = sgsize; 692 } 693 } 694 695 lastaddr = curaddr + sgsize; 696 vaddr += sgsize; 697 buflen -= sgsize; 698 } 699 700 *segp = seg; 701 *lastaddrp = lastaddr; 702 703 /* 704 * Did we fit? 705 */ 706 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 707 } 708 709 /* 710 * Map the buffer buf into bus space using the dmamap map. 711 */ 712 int 713 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 714 bus_size_t buflen, bus_dmamap_callback_t *callback, 715 void *callback_arg, int flags) 716 { 717 bus_addr_t lastaddr = 0; 718 int error, nsegs = 0; 719 720 if (map != NULL) { 721 flags |= BUS_DMA_WAITOK; 722 map->callback = callback; 723 map->callback_arg = callback_arg; 724 } 725 726 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags, 727 &lastaddr, dmat->segments, &nsegs, 1); 728 729 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 730 __func__, dmat, dmat->flags, error, nsegs + 1); 731 732 if (error == EINPROGRESS) { 733 return (error); 734 } 735 736 if (error) 737 (*callback)(callback_arg, dmat->segments, 0, error); 738 else 739 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0); 740 741 /* 742 * Return ENOMEM to the caller so that it can pass it up the stack. 743 * This error only happens when NOWAIT is set, so deferal is disabled. 744 */ 745 if (error == ENOMEM) 746 return (error); 747 748 return (0); 749 } 750 751 752 /* 753 * Like _bus_dmamap_load(), but for mbufs. 754 */ 755 int 756 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 757 struct mbuf *m0, 758 bus_dmamap_callback2_t *callback, void *callback_arg, 759 int flags) 760 { 761 int nsegs, error; 762 763 M_ASSERTPKTHDR(m0); 764 765 flags |= BUS_DMA_NOWAIT; 766 nsegs = 0; 767 error = 0; 768 if (m0->m_pkthdr.len <= dmat->maxsize) { 769 int first = 1; 770 bus_addr_t lastaddr = 0; 771 struct mbuf *m; 772 773 for (m = m0; m != NULL && error == 0; m = m->m_next) { 774 if (m->m_len > 0) { 775 error = _bus_dmamap_load_buffer(dmat, map, 776 m->m_data, m->m_len, 777 NULL, flags, &lastaddr, 778 dmat->segments, &nsegs, first); 779 first = 0; 780 } 781 } 782 } else { 783 error = EINVAL; 784 } 785 786 if (error) { 787 /* force "no valid mappings" in callback */ 788 (*callback)(callback_arg, dmat->segments, 0, 0, error); 789 } else { 790 (*callback)(callback_arg, dmat->segments, 791 nsegs+1, m0->m_pkthdr.len, error); 792 } 793 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 794 __func__, dmat, dmat->flags, error, nsegs + 1); 795 return (error); 796 } 797 798 int 799 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 800 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 801 int flags) 802 { 803 int error; 804 805 M_ASSERTPKTHDR(m0); 806 807 flags |= BUS_DMA_NOWAIT; 808 *nsegs = 0; 809 error = 0; 810 if (m0->m_pkthdr.len <= dmat->maxsize) { 811 int first = 1; 812 bus_addr_t lastaddr = 0; 813 struct mbuf *m; 814 815 for (m = m0; m != NULL && error == 0; m = m->m_next) { 816 if (m->m_len > 0) { 817 error = _bus_dmamap_load_buffer(dmat, map, 818 m->m_data, m->m_len, 819 NULL, flags, &lastaddr, 820 segs, nsegs, first); 821 first = 0; 822 } 823 } 824 } else { 825 error = EINVAL; 826 } 827 828 /* XXX FIXME: Having to increment nsegs is really annoying */ 829 ++*nsegs; 830 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 831 __func__, dmat, dmat->flags, error, *nsegs); 832 return (error); 833 } 834 835 /* 836 * Like _bus_dmamap_load(), but for uios. 837 */ 838 int 839 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 840 struct uio *uio, 841 bus_dmamap_callback2_t *callback, void *callback_arg, 842 int flags) 843 { 844 bus_addr_t lastaddr; 845 int nsegs, error, first, i; 846 bus_size_t resid; 847 struct iovec *iov; 848 pmap_t pmap; 849 850 flags |= BUS_DMA_NOWAIT; 851 resid = uio->uio_resid; 852 iov = uio->uio_iov; 853 854 if (uio->uio_segflg == UIO_USERSPACE) { 855 KASSERT(uio->uio_td != NULL, 856 ("bus_dmamap_load_uio: USERSPACE but no proc")); 857 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace); 858 } else 859 pmap = NULL; 860 861 nsegs = 0; 862 error = 0; 863 first = 1; 864 lastaddr = (bus_addr_t) 0; 865 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 866 /* 867 * Now at the first iovec to load. Load each iovec 868 * until we have exhausted the residual count. 869 */ 870 bus_size_t minlen = 871 resid < iov[i].iov_len ? resid : iov[i].iov_len; 872 caddr_t addr = (caddr_t) iov[i].iov_base; 873 874 if (minlen > 0) { 875 error = _bus_dmamap_load_buffer(dmat, map, 876 addr, minlen, pmap, flags, &lastaddr, 877 dmat->segments, &nsegs, first); 878 first = 0; 879 880 resid -= minlen; 881 } 882 } 883 884 if (error) { 885 /* force "no valid mappings" in callback */ 886 (*callback)(callback_arg, dmat->segments, 0, 0, error); 887 } else { 888 (*callback)(callback_arg, dmat->segments, 889 nsegs+1, uio->uio_resid, error); 890 } 891 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 892 __func__, dmat, dmat->flags, error, nsegs + 1); 893 return (error); 894 } 895 896 /* 897 * Release the mapping held by map. 898 */ 899 void 900 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 901 { 902 struct bounce_page *bpage; 903 904 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 905 STAILQ_REMOVE_HEAD(&map->bpages, links); 906 free_bounce_page(dmat, bpage); 907 } 908 } 909 910 void 911 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 912 { 913 struct bounce_page *bpage; 914 915 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 916 /* 917 * Handle data bouncing. We might also 918 * want to add support for invalidating 919 * the caches on broken hardware 920 */ 921 dmat->bounce_zone->total_bounced++; 922 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x " 923 "performing bounce", __func__, op, dmat, dmat->flags); 924 925 if (op & BUS_DMASYNC_PREWRITE) { 926 while (bpage != NULL) { 927 bcopy((void *)bpage->datavaddr, 928 (void *)bpage->vaddr, 929 bpage->datacount); 930 bpage = STAILQ_NEXT(bpage, links); 931 } 932 } 933 934 if (op & BUS_DMASYNC_POSTREAD) { 935 while (bpage != NULL) { 936 bcopy((void *)bpage->vaddr, 937 (void *)bpage->datavaddr, 938 bpage->datacount); 939 bpage = STAILQ_NEXT(bpage, links); 940 } 941 } 942 } 943 } 944 945 static void 946 init_bounce_pages(void *dummy __unused) 947 { 948 949 total_bpages = 0; 950 STAILQ_INIT(&bounce_zone_list); 951 STAILQ_INIT(&bounce_map_waitinglist); 952 STAILQ_INIT(&bounce_map_callbacklist); 953 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 954 } 955 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 956 957 static struct sysctl_ctx_list * 958 busdma_sysctl_tree(struct bounce_zone *bz) 959 { 960 return (&bz->sysctl_tree); 961 } 962 963 static struct sysctl_oid * 964 busdma_sysctl_tree_top(struct bounce_zone *bz) 965 { 966 return (bz->sysctl_tree_top); 967 } 968 969 static int 970 alloc_bounce_zone(bus_dma_tag_t dmat) 971 { 972 struct bounce_zone *bz; 973 974 /* Check to see if we already have a suitable zone */ 975 STAILQ_FOREACH(bz, &bounce_zone_list, links) { 976 if ((dmat->alignment <= bz->alignment) 977 && (dmat->boundary <= bz->boundary) 978 && (dmat->lowaddr >= bz->lowaddr)) { 979 dmat->bounce_zone = bz; 980 return (0); 981 } 982 } 983 984 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF, 985 M_NOWAIT | M_ZERO)) == NULL) 986 return (ENOMEM); 987 988 STAILQ_INIT(&bz->bounce_page_list); 989 bz->free_bpages = 0; 990 bz->reserved_bpages = 0; 991 bz->active_bpages = 0; 992 bz->lowaddr = dmat->lowaddr; 993 bz->alignment = dmat->alignment; 994 bz->boundary = dmat->boundary; 995 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount); 996 busdma_zonecount++; 997 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr); 998 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links); 999 dmat->bounce_zone = bz; 1000 1001 sysctl_ctx_init(&bz->sysctl_tree); 1002 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree, 1003 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid, 1004 CTLFLAG_RD, 0, ""); 1005 if (bz->sysctl_tree_top == NULL) { 1006 sysctl_ctx_free(&bz->sysctl_tree); 1007 return (0); /* XXX error code? */ 1008 } 1009 1010 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1011 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1012 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0, 1013 "Total bounce pages"); 1014 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1015 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1016 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0, 1017 "Free bounce pages"); 1018 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1019 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1020 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0, 1021 "Reserved bounce pages"); 1022 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1023 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1024 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0, 1025 "Active bounce pages"); 1026 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1027 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1028 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0, 1029 "Total bounce requests"); 1030 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1031 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1032 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0, 1033 "Total bounce requests that were deferred"); 1034 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz), 1035 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1036 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, ""); 1037 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1038 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1039 "alignment", CTLFLAG_RD, &bz->alignment, 0, ""); 1040 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1041 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1042 "boundary", CTLFLAG_RD, &bz->boundary, 0, ""); 1043 1044 return (0); 1045 } 1046 1047 static int 1048 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 1049 { 1050 struct bounce_zone *bz; 1051 int count; 1052 1053 bz = dmat->bounce_zone; 1054 count = 0; 1055 while (numpages > 0) { 1056 struct bounce_page *bpage; 1057 1058 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 1059 M_NOWAIT | M_ZERO); 1060 1061 if (bpage == NULL) 1062 break; 1063 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 1064 M_NOWAIT, 0ul, 1065 bz->lowaddr, 1066 PAGE_SIZE, 1067 bz->boundary); 1068 if (bpage->vaddr == 0) { 1069 free(bpage, M_DEVBUF); 1070 break; 1071 } 1072 bpage->busaddr = pmap_kextract(bpage->vaddr); 1073 mtx_lock(&bounce_lock); 1074 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links); 1075 total_bpages++; 1076 bz->total_bpages++; 1077 bz->free_bpages++; 1078 mtx_unlock(&bounce_lock); 1079 count++; 1080 numpages--; 1081 } 1082 return (count); 1083 } 1084 1085 static int 1086 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 1087 { 1088 struct bounce_zone *bz; 1089 int pages; 1090 1091 mtx_assert(&bounce_lock, MA_OWNED); 1092 bz = dmat->bounce_zone; 1093 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved); 1094 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 1095 return (map->pagesneeded - (map->pagesreserved + pages)); 1096 bz->free_bpages -= pages; 1097 bz->reserved_bpages += pages; 1098 map->pagesreserved += pages; 1099 pages = map->pagesneeded - map->pagesreserved; 1100 1101 return (pages); 1102 } 1103 1104 static bus_addr_t 1105 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 1106 bus_size_t size) 1107 { 1108 struct bounce_zone *bz; 1109 struct bounce_page *bpage; 1110 1111 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag")); 1112 KASSERT(map != NULL && map != &nobounce_dmamap, 1113 ("add_bounce_page: bad map %p", map)); 1114 1115 bz = dmat->bounce_zone; 1116 if (map->pagesneeded == 0) 1117 panic("add_bounce_page: map doesn't need any pages"); 1118 map->pagesneeded--; 1119 1120 if (map->pagesreserved == 0) 1121 panic("add_bounce_page: map doesn't need any pages"); 1122 map->pagesreserved--; 1123 1124 mtx_lock(&bounce_lock); 1125 bpage = STAILQ_FIRST(&bz->bounce_page_list); 1126 if (bpage == NULL) 1127 panic("add_bounce_page: free page list is empty"); 1128 1129 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links); 1130 bz->reserved_bpages--; 1131 bz->active_bpages++; 1132 mtx_unlock(&bounce_lock); 1133 1134 bpage->datavaddr = vaddr; 1135 bpage->datacount = size; 1136 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 1137 return (bpage->busaddr); 1138 } 1139 1140 static void 1141 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 1142 { 1143 struct bus_dmamap *map; 1144 struct bounce_zone *bz; 1145 1146 bz = dmat->bounce_zone; 1147 bpage->datavaddr = 0; 1148 bpage->datacount = 0; 1149 1150 mtx_lock(&bounce_lock); 1151 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links); 1152 bz->free_bpages++; 1153 bz->active_bpages--; 1154 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 1155 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 1156 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 1157 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 1158 map, links); 1159 busdma_swi_pending = 1; 1160 bz->total_deferred++; 1161 swi_sched(vm_ih, 0); 1162 } 1163 } 1164 mtx_unlock(&bounce_lock); 1165 } 1166 1167 void 1168 busdma_swi(void) 1169 { 1170 bus_dma_tag_t dmat; 1171 struct bus_dmamap *map; 1172 1173 mtx_lock(&bounce_lock); 1174 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 1175 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 1176 mtx_unlock(&bounce_lock); 1177 dmat = map->dmat; 1178 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK); 1179 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 1180 map->callback, map->callback_arg, /*flags*/0); 1181 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK); 1182 mtx_lock(&bounce_lock); 1183 } 1184 mtx_unlock(&bounce_lock); 1185 }
Cache object: ca02985454b29821bc6d03a8138fc5a8
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