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sys/i386/i386/busdma_machdep.c
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1 /*- 2 * Copyright (c) 1997, 1998 Justin T. Gibbs. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions, and the following disclaimer, 10 * without modification, immediately at the beginning of the file. 11 * 2. The name of the author may not be used to endorse or promote products 12 * derived from this software without specific prior written permission. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 18 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD: releng/7.4/sys/i386/i386/busdma_machdep.c 200289 2009-12-09 08:16:12Z scottl $"); 29 30 #include <sys/param.h> 31 #include <sys/kdb.h> 32 #include <ddb/ddb.h> 33 #include <ddb/db_output.h> 34 #include <sys/systm.h> 35 #include <sys/malloc.h> 36 #include <sys/bus.h> 37 #include <sys/interrupt.h> 38 #include <sys/kernel.h> 39 #include <sys/ktr.h> 40 #include <sys/lock.h> 41 #include <sys/proc.h> 42 #include <sys/mutex.h> 43 #include <sys/mbuf.h> 44 #include <sys/uio.h> 45 #include <sys/sysctl.h> 46 47 #include <vm/vm.h> 48 #include <vm/vm_page.h> 49 #include <vm/vm_map.h> 50 51 #include <machine/atomic.h> 52 #include <machine/bus.h> 53 #include <machine/md_var.h> 54 #include <machine/specialreg.h> 55 56 #define MAX_BPAGES 512 57 #define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3 58 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 59 60 struct bounce_zone; 61 62 struct bus_dma_tag { 63 bus_dma_tag_t parent; 64 bus_size_t alignment; 65 bus_size_t boundary; 66 bus_addr_t lowaddr; 67 bus_addr_t highaddr; 68 bus_dma_filter_t *filter; 69 void *filterarg; 70 bus_size_t maxsize; 71 u_int nsegments; 72 bus_size_t maxsegsz; 73 int flags; 74 int ref_count; 75 int map_count; 76 bus_dma_lock_t *lockfunc; 77 void *lockfuncarg; 78 bus_dma_segment_t *segments; 79 struct bounce_zone *bounce_zone; 80 }; 81 82 struct bounce_page { 83 vm_offset_t vaddr; /* kva of bounce buffer */ 84 bus_addr_t busaddr; /* Physical address */ 85 vm_offset_t datavaddr; /* kva of client data */ 86 bus_size_t datacount; /* client data count */ 87 STAILQ_ENTRY(bounce_page) links; 88 }; 89 90 int busdma_swi_pending; 91 92 struct bounce_zone { 93 STAILQ_ENTRY(bounce_zone) links; 94 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 95 int total_bpages; 96 int free_bpages; 97 int reserved_bpages; 98 int active_bpages; 99 int total_bounced; 100 int total_deferred; 101 bus_size_t alignment; 102 bus_addr_t lowaddr; 103 char zoneid[8]; 104 char lowaddrid[20]; 105 struct sysctl_ctx_list sysctl_tree; 106 struct sysctl_oid *sysctl_tree_top; 107 }; 108 109 static struct mtx bounce_lock; 110 static int total_bpages; 111 static int busdma_zonecount; 112 static STAILQ_HEAD(, bounce_zone) bounce_zone_list; 113 114 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters"); 115 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0, 116 "Total bounce pages"); 117 118 struct bus_dmamap { 119 struct bp_list bpages; 120 int pagesneeded; 121 int pagesreserved; 122 bus_dma_tag_t dmat; 123 void *buf; /* unmapped buffer pointer */ 124 bus_size_t buflen; /* unmapped buffer length */ 125 bus_dmamap_callback_t *callback; 126 void *callback_arg; 127 STAILQ_ENTRY(bus_dmamap) links; 128 }; 129 130 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 131 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 132 static struct bus_dmamap nobounce_dmamap; 133 134 static void init_bounce_pages(void *dummy); 135 static int alloc_bounce_zone(bus_dma_tag_t dmat); 136 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 137 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, 138 int commit); 139 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 140 vm_offset_t vaddr, bus_size_t size); 141 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 142 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 143 int _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap, 144 void *buf, bus_size_t buflen, int flags); 145 146 /* 147 * Return true if a match is made. 148 * 149 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 150 * 151 * If paddr is within the bounds of the dma tag then call the filter callback 152 * to check for a match, if there is no filter callback then assume a match. 153 */ 154 int 155 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 156 { 157 int retval; 158 159 retval = 0; 160 161 do { 162 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) 163 || ((paddr & (dmat->alignment - 1)) != 0)) 164 && (dmat->filter == NULL 165 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 166 retval = 1; 167 168 dmat = dmat->parent; 169 } while (retval == 0 && dmat != NULL); 170 return (retval); 171 } 172 173 /* 174 * Convenience function for manipulating driver locks from busdma (during 175 * busdma_swi, for example). Drivers that don't provide their own locks 176 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own 177 * non-mutex locking scheme don't have to use this at all. 178 */ 179 void 180 busdma_lock_mutex(void *arg, bus_dma_lock_op_t op) 181 { 182 struct mtx *dmtx; 183 184 dmtx = (struct mtx *)arg; 185 switch (op) { 186 case BUS_DMA_LOCK: 187 mtx_lock(dmtx); 188 break; 189 case BUS_DMA_UNLOCK: 190 mtx_unlock(dmtx); 191 break; 192 default: 193 panic("Unknown operation 0x%x for busdma_lock_mutex!", op); 194 } 195 } 196 197 /* 198 * dflt_lock should never get called. It gets put into the dma tag when 199 * lockfunc == NULL, which is only valid if the maps that are associated 200 * with the tag are meant to never be defered. 201 * XXX Should have a way to identify which driver is responsible here. 202 */ 203 static void 204 dflt_lock(void *arg, bus_dma_lock_op_t op) 205 { 206 panic("driver error: busdma dflt_lock called"); 207 } 208 209 /* 210 * Allocate a device specific dma_tag. 211 */ 212 int 213 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 214 bus_size_t boundary, bus_addr_t lowaddr, 215 bus_addr_t highaddr, bus_dma_filter_t *filter, 216 void *filterarg, bus_size_t maxsize, int nsegments, 217 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc, 218 void *lockfuncarg, bus_dma_tag_t *dmat) 219 { 220 bus_dma_tag_t newtag; 221 int error = 0; 222 223 /* Basic sanity checking */ 224 if (boundary != 0 && boundary < maxsegsz) 225 maxsegsz = boundary; 226 227 if (maxsegsz == 0) { 228 return (EINVAL); 229 } 230 231 /* Return a NULL tag on failure */ 232 *dmat = NULL; 233 234 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, 235 M_ZERO | M_NOWAIT); 236 if (newtag == NULL) { 237 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 238 __func__, newtag, 0, error); 239 return (ENOMEM); 240 } 241 242 newtag->parent = parent; 243 newtag->alignment = alignment; 244 newtag->boundary = boundary; 245 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 246 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + 247 (PAGE_SIZE - 1); 248 newtag->filter = filter; 249 newtag->filterarg = filterarg; 250 newtag->maxsize = maxsize; 251 newtag->nsegments = nsegments; 252 newtag->maxsegsz = maxsegsz; 253 newtag->flags = flags; 254 newtag->ref_count = 1; /* Count ourself */ 255 newtag->map_count = 0; 256 if (lockfunc != NULL) { 257 newtag->lockfunc = lockfunc; 258 newtag->lockfuncarg = lockfuncarg; 259 } else { 260 newtag->lockfunc = dflt_lock; 261 newtag->lockfuncarg = NULL; 262 } 263 newtag->segments = NULL; 264 265 /* Take into account any restrictions imposed by our parent tag */ 266 if (parent != NULL) { 267 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 268 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 269 if (newtag->boundary == 0) 270 newtag->boundary = parent->boundary; 271 else if (parent->boundary != 0) 272 newtag->boundary = MIN(parent->boundary, 273 newtag->boundary); 274 if ((newtag->filter != NULL) || 275 ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0)) 276 newtag->flags |= BUS_DMA_COULD_BOUNCE; 277 if (newtag->filter == NULL) { 278 /* 279 * Short circuit looking at our parent directly 280 * since we have encapsulated all of its information 281 */ 282 newtag->filter = parent->filter; 283 newtag->filterarg = parent->filterarg; 284 newtag->parent = parent->parent; 285 } 286 if (newtag->parent != NULL) 287 atomic_add_int(&parent->ref_count, 1); 288 } 289 290 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) 291 || newtag->alignment > 1) 292 newtag->flags |= BUS_DMA_COULD_BOUNCE; 293 294 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) && 295 (flags & BUS_DMA_ALLOCNOW) != 0) { 296 struct bounce_zone *bz; 297 298 /* Must bounce */ 299 300 if ((error = alloc_bounce_zone(newtag)) != 0) { 301 free(newtag, M_DEVBUF); 302 return (error); 303 } 304 bz = newtag->bounce_zone; 305 306 if (ptoa(bz->total_bpages) < maxsize) { 307 int pages; 308 309 pages = atop(maxsize) - bz->total_bpages; 310 311 /* Add pages to our bounce pool */ 312 if (alloc_bounce_pages(newtag, pages) < pages) 313 error = ENOMEM; 314 } 315 /* Performed initial allocation */ 316 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 317 } 318 319 if (error != 0) { 320 free(newtag, M_DEVBUF); 321 } else { 322 *dmat = newtag; 323 } 324 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 325 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error); 326 return (error); 327 } 328 329 int 330 bus_dma_tag_destroy(bus_dma_tag_t dmat) 331 { 332 bus_dma_tag_t dmat_copy; 333 int error; 334 335 error = 0; 336 dmat_copy = dmat; 337 338 if (dmat != NULL) { 339 340 if (dmat->map_count != 0) { 341 error = EBUSY; 342 goto out; 343 } 344 345 while (dmat != NULL) { 346 bus_dma_tag_t parent; 347 348 parent = dmat->parent; 349 atomic_subtract_int(&dmat->ref_count, 1); 350 if (dmat->ref_count == 0) { 351 if (dmat->segments != NULL) 352 free(dmat->segments, M_DEVBUF); 353 free(dmat, M_DEVBUF); 354 /* 355 * Last reference count, so 356 * release our reference 357 * count on our parent. 358 */ 359 dmat = parent; 360 } else 361 dmat = NULL; 362 } 363 } 364 out: 365 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error); 366 return (error); 367 } 368 369 /* 370 * Allocate a handle for mapping from kva/uva/physical 371 * address space into bus device space. 372 */ 373 int 374 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 375 { 376 int error; 377 378 error = 0; 379 380 if (dmat->segments == NULL) { 381 dmat->segments = (bus_dma_segment_t *)malloc( 382 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 383 M_NOWAIT); 384 if (dmat->segments == NULL) { 385 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 386 __func__, dmat, ENOMEM); 387 return (ENOMEM); 388 } 389 } 390 391 /* 392 * Bouncing might be required if the driver asks for an active 393 * exclusion region, a data alignment that is stricter than 1, and/or 394 * an active address boundary. 395 */ 396 if (dmat->flags & BUS_DMA_COULD_BOUNCE) { 397 398 /* Must bounce */ 399 struct bounce_zone *bz; 400 int maxpages; 401 402 if (dmat->bounce_zone == NULL) { 403 if ((error = alloc_bounce_zone(dmat)) != 0) 404 return (error); 405 } 406 bz = dmat->bounce_zone; 407 408 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 409 M_NOWAIT | M_ZERO); 410 if (*mapp == NULL) { 411 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 412 __func__, dmat, ENOMEM); 413 return (ENOMEM); 414 } 415 416 /* Initialize the new map */ 417 STAILQ_INIT(&((*mapp)->bpages)); 418 419 /* 420 * Attempt to add pages to our pool on a per-instance 421 * basis up to a sane limit. 422 */ 423 if (dmat->alignment > 1) 424 maxpages = MAX_BPAGES; 425 else 426 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr)); 427 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 428 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) { 429 int pages; 430 431 pages = MAX(atop(dmat->maxsize), 1); 432 pages = MIN(maxpages - bz->total_bpages, pages); 433 pages = MAX(pages, 1); 434 if (alloc_bounce_pages(dmat, pages) < pages) 435 error = ENOMEM; 436 437 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 438 if (error == 0) 439 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 440 } else { 441 error = 0; 442 } 443 } 444 } else { 445 *mapp = NULL; 446 } 447 if (error == 0) 448 dmat->map_count++; 449 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 450 __func__, dmat, dmat->flags, error); 451 return (error); 452 } 453 454 /* 455 * Destroy a handle for mapping from kva/uva/physical 456 * address space into bus device space. 457 */ 458 int 459 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 460 { 461 if (map != NULL && map != &nobounce_dmamap) { 462 if (STAILQ_FIRST(&map->bpages) != NULL) { 463 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 464 __func__, dmat, EBUSY); 465 return (EBUSY); 466 } 467 free(map, M_DEVBUF); 468 } 469 dmat->map_count--; 470 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat); 471 return (0); 472 } 473 474 475 /* 476 * Allocate a piece of memory that can be efficiently mapped into 477 * bus device space based on the constraints lited in the dma tag. 478 * A dmamap to for use with dmamap_load is also allocated. 479 */ 480 int 481 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 482 bus_dmamap_t *mapp) 483 { 484 int mflags; 485 486 if (flags & BUS_DMA_NOWAIT) 487 mflags = M_NOWAIT; 488 else 489 mflags = M_WAITOK; 490 if (flags & BUS_DMA_ZERO) 491 mflags |= M_ZERO; 492 493 /* If we succeed, no mapping/bouncing will be required */ 494 *mapp = NULL; 495 496 if (dmat->segments == NULL) { 497 dmat->segments = (bus_dma_segment_t *)malloc( 498 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 499 M_NOWAIT); 500 if (dmat->segments == NULL) { 501 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 502 __func__, dmat, dmat->flags, ENOMEM); 503 return (ENOMEM); 504 } 505 } 506 507 /* 508 * XXX: 509 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact 510 * alignment guarantees of malloc need to be nailed down, and the 511 * code below should be rewritten to take that into account. 512 * 513 * In the meantime, we'll warn the user if malloc gets it wrong. 514 */ 515 if ((dmat->maxsize <= PAGE_SIZE) && 516 (dmat->alignment < dmat->maxsize) && 517 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 518 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags); 519 } else { 520 /* 521 * XXX Use Contigmalloc until it is merged into this facility 522 * and handles multi-seg allocations. Nobody is doing 523 * multi-seg allocations yet though. 524 * XXX Certain AGP hardware does. 525 */ 526 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags, 527 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 528 dmat->boundary); 529 } 530 if (*vaddr == NULL) { 531 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 532 __func__, dmat, dmat->flags, ENOMEM); 533 return (ENOMEM); 534 } else if ((uintptr_t)*vaddr & (dmat->alignment - 1)) { 535 printf("bus_dmamem_alloc failed to align memory properly.\n"); 536 } 537 if (flags & BUS_DMA_NOCACHE) 538 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize, 539 PAT_UNCACHEABLE); 540 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 541 __func__, dmat, dmat->flags, ENOMEM); 542 return (0); 543 } 544 545 /* 546 * Free a piece of memory and it's allociated dmamap, that was allocated 547 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 548 */ 549 void 550 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 551 { 552 /* 553 * dmamem does not need to be bounced, so the map should be 554 * NULL 555 */ 556 if (map != NULL) 557 panic("bus_dmamem_free: Invalid map freed\n"); 558 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK); 559 if ((dmat->maxsize <= PAGE_SIZE) && 560 (dmat->alignment < dmat->maxsize) && 561 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 562 free(vaddr, M_DEVBUF); 563 else { 564 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 565 } 566 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags); 567 } 568 569 int 570 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap, 571 void *buf, bus_size_t buflen, int flags) 572 { 573 vm_offset_t vaddr; 574 vm_offset_t vendaddr; 575 bus_addr_t paddr; 576 577 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) { 578 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, " 579 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem), 580 dmat->boundary, dmat->alignment); 581 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d", 582 map, &nobounce_dmamap, map->pagesneeded); 583 /* 584 * Count the number of bounce pages 585 * needed in order to complete this transfer 586 */ 587 vaddr = (vm_offset_t)buf; 588 vendaddr = (vm_offset_t)buf + buflen; 589 590 while (vaddr < vendaddr) { 591 if (pmap) 592 paddr = pmap_extract(pmap, vaddr); 593 else 594 paddr = pmap_kextract(vaddr); 595 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) && 596 run_filter(dmat, paddr) != 0) { 597 map->pagesneeded++; 598 } 599 vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK)); 600 } 601 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded); 602 } 603 604 /* Reserve Necessary Bounce Pages */ 605 if (map->pagesneeded != 0) { 606 mtx_lock(&bounce_lock); 607 if (flags & BUS_DMA_NOWAIT) { 608 if (reserve_bounce_pages(dmat, map, 0) != 0) { 609 mtx_unlock(&bounce_lock); 610 return (ENOMEM); 611 } 612 } else { 613 if (reserve_bounce_pages(dmat, map, 1) != 0) { 614 /* Queue us for resources */ 615 map->dmat = dmat; 616 map->buf = buf; 617 map->buflen = buflen; 618 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 619 map, links); 620 mtx_unlock(&bounce_lock); 621 return (EINPROGRESS); 622 } 623 } 624 mtx_unlock(&bounce_lock); 625 } 626 627 return (0); 628 } 629 630 /* 631 * Utility function to load a linear buffer. lastaddrp holds state 632 * between invocations (for multiple-buffer loads). segp contains 633 * the starting segment on entrace, and the ending segment on exit. 634 * first indicates if this is the first invocation of this function. 635 */ 636 static __inline int 637 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, 638 bus_dmamap_t map, 639 void *buf, bus_size_t buflen, 640 pmap_t pmap, 641 int flags, 642 bus_addr_t *lastaddrp, 643 bus_dma_segment_t *segs, 644 int *segp, 645 int first) 646 { 647 bus_size_t sgsize; 648 bus_addr_t curaddr, lastaddr, baddr, bmask; 649 vm_offset_t vaddr; 650 int seg, error; 651 652 if (map == NULL) 653 map = &nobounce_dmamap; 654 655 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) { 656 error = _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags); 657 if (error) 658 return (error); 659 } 660 661 vaddr = (vm_offset_t)buf; 662 lastaddr = *lastaddrp; 663 bmask = ~(dmat->boundary - 1); 664 665 for (seg = *segp; buflen > 0 ; ) { 666 /* 667 * Get the physical address for this segment. 668 */ 669 if (pmap) 670 curaddr = pmap_extract(pmap, vaddr); 671 else 672 curaddr = pmap_kextract(vaddr); 673 674 /* 675 * Compute the segment size, and adjust counts. 676 */ 677 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK); 678 if (sgsize > dmat->maxsegsz) 679 sgsize = dmat->maxsegsz; 680 if (buflen < sgsize) 681 sgsize = buflen; 682 683 /* 684 * Make sure we don't cross any boundaries. 685 */ 686 if (dmat->boundary > 0) { 687 baddr = (curaddr + dmat->boundary) & bmask; 688 if (sgsize > (baddr - curaddr)) 689 sgsize = (baddr - curaddr); 690 } 691 692 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) && 693 map->pagesneeded != 0 && run_filter(dmat, curaddr)) 694 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 695 696 /* 697 * Insert chunk into a segment, coalescing with 698 * previous segment if possible. 699 */ 700 if (first) { 701 segs[seg].ds_addr = curaddr; 702 segs[seg].ds_len = sgsize; 703 first = 0; 704 } else { 705 if (curaddr == lastaddr && 706 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 707 (dmat->boundary == 0 || 708 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 709 segs[seg].ds_len += sgsize; 710 else { 711 if (++seg >= dmat->nsegments) 712 break; 713 segs[seg].ds_addr = curaddr; 714 segs[seg].ds_len = sgsize; 715 } 716 } 717 718 lastaddr = curaddr + sgsize; 719 vaddr += sgsize; 720 buflen -= sgsize; 721 } 722 723 *segp = seg; 724 *lastaddrp = lastaddr; 725 726 /* 727 * Did we fit? 728 */ 729 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 730 } 731 732 /* 733 * Map the buffer buf into bus space using the dmamap map. 734 */ 735 int 736 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 737 bus_size_t buflen, bus_dmamap_callback_t *callback, 738 void *callback_arg, int flags) 739 { 740 bus_addr_t lastaddr = 0; 741 int error, nsegs = 0; 742 743 if (map != NULL) { 744 flags |= BUS_DMA_WAITOK; 745 map->callback = callback; 746 map->callback_arg = callback_arg; 747 } 748 749 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags, 750 &lastaddr, dmat->segments, &nsegs, 1); 751 752 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 753 __func__, dmat, dmat->flags, error, nsegs + 1); 754 755 if (error == EINPROGRESS) { 756 return (error); 757 } 758 759 if (error) 760 (*callback)(callback_arg, dmat->segments, 0, error); 761 else 762 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0); 763 764 /* 765 * Return ENOMEM to the caller so that it can pass it up the stack. 766 * This error only happens when NOWAIT is set, so deferal is disabled. 767 */ 768 if (error == ENOMEM) 769 return (error); 770 771 return (0); 772 } 773 774 775 /* 776 * Like _bus_dmamap_load(), but for mbufs. 777 */ 778 static __inline int 779 _bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 780 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 781 int flags) 782 { 783 int error; 784 785 M_ASSERTPKTHDR(m0); 786 787 flags |= BUS_DMA_NOWAIT; 788 *nsegs = 0; 789 error = 0; 790 if (m0->m_pkthdr.len <= dmat->maxsize) { 791 int first = 1; 792 bus_addr_t lastaddr = 0; 793 struct mbuf *m; 794 795 for (m = m0; m != NULL && error == 0; m = m->m_next) { 796 if (m->m_len > 0) { 797 error = _bus_dmamap_load_buffer(dmat, map, 798 m->m_data, m->m_len, 799 NULL, flags, &lastaddr, 800 segs, nsegs, first); 801 first = 0; 802 } 803 } 804 } else { 805 error = EINVAL; 806 } 807 808 /* XXX FIXME: Having to increment nsegs is really annoying */ 809 ++*nsegs; 810 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 811 __func__, dmat, dmat->flags, error, *nsegs); 812 return (error); 813 } 814 815 int 816 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 817 struct mbuf *m0, 818 bus_dmamap_callback2_t *callback, void *callback_arg, 819 int flags) 820 { 821 int nsegs, error; 822 823 error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, dmat->segments, &nsegs, 824 flags); 825 826 if (error) { 827 /* force "no valid mappings" in callback */ 828 (*callback)(callback_arg, dmat->segments, 0, 0, error); 829 } else { 830 (*callback)(callback_arg, dmat->segments, 831 nsegs, m0->m_pkthdr.len, error); 832 } 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 int 839 bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 840 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 841 int flags) 842 { 843 return (_bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags)); 844 } 845 846 /* 847 * Like _bus_dmamap_load(), but for uios. 848 */ 849 int 850 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 851 struct uio *uio, 852 bus_dmamap_callback2_t *callback, void *callback_arg, 853 int flags) 854 { 855 bus_addr_t lastaddr; 856 int nsegs, error, first, i; 857 bus_size_t resid; 858 struct iovec *iov; 859 pmap_t pmap; 860 861 flags |= BUS_DMA_NOWAIT; 862 resid = uio->uio_resid; 863 iov = uio->uio_iov; 864 865 if (uio->uio_segflg == UIO_USERSPACE) { 866 KASSERT(uio->uio_td != NULL, 867 ("bus_dmamap_load_uio: USERSPACE but no proc")); 868 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace); 869 } else 870 pmap = NULL; 871 872 nsegs = 0; 873 error = 0; 874 first = 1; 875 lastaddr = (bus_addr_t) 0; 876 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 877 /* 878 * Now at the first iovec to load. Load each iovec 879 * until we have exhausted the residual count. 880 */ 881 bus_size_t minlen = 882 resid < iov[i].iov_len ? resid : iov[i].iov_len; 883 caddr_t addr = (caddr_t) iov[i].iov_base; 884 885 if (minlen > 0) { 886 error = _bus_dmamap_load_buffer(dmat, map, 887 addr, minlen, pmap, flags, &lastaddr, 888 dmat->segments, &nsegs, first); 889 first = 0; 890 891 resid -= minlen; 892 } 893 } 894 895 if (error) { 896 /* force "no valid mappings" in callback */ 897 (*callback)(callback_arg, dmat->segments, 0, 0, error); 898 } else { 899 (*callback)(callback_arg, dmat->segments, 900 nsegs+1, uio->uio_resid, error); 901 } 902 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 903 __func__, dmat, dmat->flags, error, nsegs + 1); 904 return (error); 905 } 906 907 /* 908 * Release the mapping held by map. 909 */ 910 void 911 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 912 { 913 struct bounce_page *bpage; 914 915 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 916 STAILQ_REMOVE_HEAD(&map->bpages, links); 917 free_bounce_page(dmat, bpage); 918 } 919 } 920 921 void 922 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 923 { 924 struct bounce_page *bpage; 925 926 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 927 /* 928 * Handle data bouncing. We might also 929 * want to add support for invalidating 930 * the caches on broken hardware 931 */ 932 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x " 933 "performing bounce", __func__, op, dmat, dmat->flags); 934 935 if (op & BUS_DMASYNC_PREWRITE) { 936 while (bpage != NULL) { 937 bcopy((void *)bpage->datavaddr, 938 (void *)bpage->vaddr, 939 bpage->datacount); 940 bpage = STAILQ_NEXT(bpage, links); 941 } 942 dmat->bounce_zone->total_bounced++; 943 } 944 945 if (op & BUS_DMASYNC_POSTREAD) { 946 while (bpage != NULL) { 947 bcopy((void *)bpage->vaddr, 948 (void *)bpage->datavaddr, 949 bpage->datacount); 950 bpage = STAILQ_NEXT(bpage, links); 951 } 952 dmat->bounce_zone->total_bounced++; 953 } 954 } 955 } 956 957 static void 958 init_bounce_pages(void *dummy __unused) 959 { 960 961 total_bpages = 0; 962 STAILQ_INIT(&bounce_zone_list); 963 STAILQ_INIT(&bounce_map_waitinglist); 964 STAILQ_INIT(&bounce_map_callbacklist); 965 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 966 } 967 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 968 969 static struct sysctl_ctx_list * 970 busdma_sysctl_tree(struct bounce_zone *bz) 971 { 972 return (&bz->sysctl_tree); 973 } 974 975 static struct sysctl_oid * 976 busdma_sysctl_tree_top(struct bounce_zone *bz) 977 { 978 return (bz->sysctl_tree_top); 979 } 980 981 static int 982 alloc_bounce_zone(bus_dma_tag_t dmat) 983 { 984 struct bounce_zone *bz; 985 986 /* Check to see if we already have a suitable zone */ 987 STAILQ_FOREACH(bz, &bounce_zone_list, links) { 988 if ((dmat->alignment <= bz->alignment) 989 && (dmat->lowaddr >= bz->lowaddr)) { 990 dmat->bounce_zone = bz; 991 return (0); 992 } 993 } 994 995 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF, 996 M_NOWAIT | M_ZERO)) == NULL) 997 return (ENOMEM); 998 999 STAILQ_INIT(&bz->bounce_page_list); 1000 bz->free_bpages = 0; 1001 bz->reserved_bpages = 0; 1002 bz->active_bpages = 0; 1003 bz->lowaddr = dmat->lowaddr; 1004 bz->alignment = MAX(dmat->alignment, PAGE_SIZE); 1005 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount); 1006 busdma_zonecount++; 1007 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr); 1008 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links); 1009 dmat->bounce_zone = bz; 1010 1011 sysctl_ctx_init(&bz->sysctl_tree); 1012 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree, 1013 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid, 1014 CTLFLAG_RD, 0, ""); 1015 if (bz->sysctl_tree_top == NULL) { 1016 sysctl_ctx_free(&bz->sysctl_tree); 1017 return (0); /* XXX error code? */ 1018 } 1019 1020 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1021 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1022 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0, 1023 "Total bounce pages"); 1024 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1025 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1026 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0, 1027 "Free bounce pages"); 1028 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1029 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1030 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0, 1031 "Reserved bounce pages"); 1032 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1033 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1034 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0, 1035 "Active bounce pages"); 1036 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1037 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1038 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0, 1039 "Total bounce requests"); 1040 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1041 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1042 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0, 1043 "Total bounce requests that were deferred"); 1044 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz), 1045 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1046 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, ""); 1047 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1048 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1049 "alignment", CTLFLAG_RD, &bz->alignment, 0, ""); 1050 1051 return (0); 1052 } 1053 1054 static int 1055 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 1056 { 1057 struct bounce_zone *bz; 1058 int count; 1059 1060 bz = dmat->bounce_zone; 1061 count = 0; 1062 while (numpages > 0) { 1063 struct bounce_page *bpage; 1064 1065 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 1066 M_NOWAIT | M_ZERO); 1067 1068 if (bpage == NULL) 1069 break; 1070 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 1071 M_NOWAIT, 0ul, 1072 bz->lowaddr, 1073 PAGE_SIZE, 1074 0); 1075 if (bpage->vaddr == 0) { 1076 free(bpage, M_DEVBUF); 1077 break; 1078 } 1079 bpage->busaddr = pmap_kextract(bpage->vaddr); 1080 mtx_lock(&bounce_lock); 1081 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links); 1082 total_bpages++; 1083 bz->total_bpages++; 1084 bz->free_bpages++; 1085 mtx_unlock(&bounce_lock); 1086 count++; 1087 numpages--; 1088 } 1089 return (count); 1090 } 1091 1092 static int 1093 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 1094 { 1095 struct bounce_zone *bz; 1096 int pages; 1097 1098 mtx_assert(&bounce_lock, MA_OWNED); 1099 bz = dmat->bounce_zone; 1100 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved); 1101 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 1102 return (map->pagesneeded - (map->pagesreserved + pages)); 1103 bz->free_bpages -= pages; 1104 bz->reserved_bpages += pages; 1105 map->pagesreserved += pages; 1106 pages = map->pagesneeded - map->pagesreserved; 1107 1108 return (pages); 1109 } 1110 1111 static bus_addr_t 1112 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 1113 bus_size_t size) 1114 { 1115 struct bounce_zone *bz; 1116 struct bounce_page *bpage; 1117 1118 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag")); 1119 KASSERT(map != NULL && map != &nobounce_dmamap, 1120 ("add_bounce_page: bad map %p", map)); 1121 1122 bz = dmat->bounce_zone; 1123 if (map->pagesneeded == 0) 1124 panic("add_bounce_page: map doesn't need any pages"); 1125 map->pagesneeded--; 1126 1127 if (map->pagesreserved == 0) 1128 panic("add_bounce_page: map doesn't need any pages"); 1129 map->pagesreserved--; 1130 1131 mtx_lock(&bounce_lock); 1132 bpage = STAILQ_FIRST(&bz->bounce_page_list); 1133 if (bpage == NULL) 1134 panic("add_bounce_page: free page list is empty"); 1135 1136 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links); 1137 bz->reserved_bpages--; 1138 bz->active_bpages++; 1139 mtx_unlock(&bounce_lock); 1140 1141 bpage->datavaddr = vaddr; 1142 bpage->datacount = size; 1143 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 1144 return (bpage->busaddr); 1145 } 1146 1147 static void 1148 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 1149 { 1150 struct bus_dmamap *map; 1151 struct bounce_zone *bz; 1152 1153 bz = dmat->bounce_zone; 1154 bpage->datavaddr = 0; 1155 bpage->datacount = 0; 1156 1157 mtx_lock(&bounce_lock); 1158 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links); 1159 bz->free_bpages++; 1160 bz->active_bpages--; 1161 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 1162 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 1163 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 1164 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 1165 map, links); 1166 busdma_swi_pending = 1; 1167 bz->total_deferred++; 1168 swi_sched(vm_ih, 0); 1169 } 1170 } 1171 mtx_unlock(&bounce_lock); 1172 } 1173 1174 void 1175 busdma_swi(void) 1176 { 1177 bus_dma_tag_t dmat; 1178 struct bus_dmamap *map; 1179 1180 mtx_lock(&bounce_lock); 1181 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 1182 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 1183 mtx_unlock(&bounce_lock); 1184 dmat = map->dmat; 1185 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK); 1186 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 1187 map->callback, map->callback_arg, /*flags*/0); 1188 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK); 1189 mtx_lock(&bounce_lock); 1190 } 1191 mtx_unlock(&bounce_lock); 1192 }
Cache object: b959ac6e09bee65bc67ad19cff24e611
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