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 * $FreeBSD: src/sys/i386/i386/busdma_machdep.c,v 1.94 2008/08/15 20:51:31 kmacy Exp $ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/malloc.h> 32 #include <sys/mbuf.h> 33 #include <sys/uio.h> 34 #include <sys/bus_dma.h> 35 #include <sys/kernel.h> 36 #include <sys/sysctl.h> 37 #include <sys/lock.h> 38 39 #include <sys/thread2.h> 40 #include <sys/spinlock2.h> 41 #include <sys/mplock2.h> 42 43 #include <vm/vm.h> 44 #include <vm/vm_page.h> 45 46 /* XXX needed for to access pmap to convert per-proc virtual to physical */ 47 #include <sys/proc.h> 48 #include <sys/lock.h> 49 #include <vm/vm_map.h> 50 51 #include <machine/md_var.h> 52 53 #define MAX_BPAGES 1024 54 55 /* 56 * 16 x N declared on stack. 57 */ 58 #define BUS_DMA_CACHE_SEGMENTS 8 59 60 struct bounce_zone; 61 struct bus_dmamap; 62 63 struct bus_dma_tag { 64 bus_dma_tag_t parent; 65 bus_size_t alignment; 66 bus_size_t boundary; 67 bus_addr_t lowaddr; 68 bus_addr_t highaddr; 69 bus_dma_filter_t *filter; 70 void *filterarg; 71 bus_size_t maxsize; 72 u_int nsegments; 73 bus_size_t maxsegsz; 74 int flags; 75 int ref_count; 76 int map_count; 77 bus_dma_segment_t *segments; 78 struct bounce_zone *bounce_zone; 79 struct spinlock spin; 80 }; 81 82 /* 83 * bus_dma_tag private flags 84 */ 85 #define BUS_DMA_BOUNCE_ALIGN BUS_DMA_BUS2 86 #define BUS_DMA_BOUNCE_LOWADDR BUS_DMA_BUS3 87 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 88 89 #define BUS_DMA_COULD_BOUNCE (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN) 90 91 #define BUS_DMAMEM_KMALLOC(dmat) \ 92 ((dmat)->maxsize <= PAGE_SIZE && \ 93 (dmat)->alignment <= PAGE_SIZE && \ 94 (dmat)->lowaddr >= ptoa(Maxmem)) 95 96 struct bounce_page { 97 vm_offset_t vaddr; /* kva of bounce buffer */ 98 bus_addr_t busaddr; /* Physical address */ 99 vm_offset_t datavaddr; /* kva of client data */ 100 bus_size_t datacount; /* client data count */ 101 STAILQ_ENTRY(bounce_page) links; 102 }; 103 104 struct bounce_zone { 105 STAILQ_ENTRY(bounce_zone) links; 106 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 107 STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 108 struct spinlock spin; 109 int total_bpages; 110 int free_bpages; 111 int reserved_bpages; 112 int active_bpages; 113 int total_bounced; 114 int total_deferred; 115 int reserve_failed; 116 bus_size_t alignment; 117 bus_addr_t lowaddr; 118 char zoneid[8]; 119 char lowaddrid[20]; 120 struct sysctl_ctx_list sysctl_ctx; 121 struct sysctl_oid *sysctl_tree; 122 }; 123 124 #define BZ_LOCK(bz) spin_lock(&(bz)->spin) 125 #define BZ_UNLOCK(bz) spin_unlock(&(bz)->spin) 126 127 static struct lwkt_token bounce_zone_tok = 128 LWKT_TOKEN_INITIALIZER(bounce_zone_token); 129 static int busdma_zonecount; 130 static STAILQ_HEAD(, bounce_zone) bounce_zone_list = 131 STAILQ_HEAD_INITIALIZER(bounce_zone_list); 132 133 static int busdma_priv_zonecount = -1; 134 135 int busdma_swi_pending; 136 static int total_bounce_pages; 137 static int max_bounce_pages = MAX_BPAGES; 138 static int bounce_alignment = 1; /* XXX temporary */ 139 140 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages); 141 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment); 142 143 struct bus_dmamap { 144 struct bp_list bpages; 145 int pagesneeded; 146 int pagesreserved; 147 bus_dma_tag_t dmat; 148 void *buf; /* unmapped buffer pointer */ 149 bus_size_t buflen; /* unmapped buffer length */ 150 bus_dmamap_callback_t *callback; 151 void *callback_arg; 152 STAILQ_ENTRY(bus_dmamap) links; 153 }; 154 155 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist = 156 STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist); 157 static struct spinlock bounce_map_list_spin = 158 SPINLOCK_INITIALIZER(&bounce_map_list_spin); 159 160 static struct bus_dmamap nobounce_dmamap; 161 162 static int alloc_bounce_zone(bus_dma_tag_t); 163 static int alloc_bounce_pages(bus_dma_tag_t, u_int, int); 164 static void free_bounce_pages_all(bus_dma_tag_t); 165 static void free_bounce_zone(bus_dma_tag_t); 166 static int reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int); 167 static void return_bounce_pages(bus_dma_tag_t, bus_dmamap_t); 168 static bus_addr_t add_bounce_page(bus_dma_tag_t, bus_dmamap_t, 169 vm_offset_t, bus_size_t); 170 static void free_bounce_page(bus_dma_tag_t, struct bounce_page *); 171 172 static bus_dmamap_t get_map_waiting(bus_dma_tag_t); 173 static void add_map_callback(bus_dmamap_t); 174 175 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters"); 176 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages, 177 0, "Total bounce pages"); 178 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages, 179 0, "Max bounce pages per bounce zone"); 180 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD, 181 &bounce_alignment, 0, "Obey alignment constraint"); 182 183 static __inline int 184 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 185 { 186 int retval; 187 188 retval = 0; 189 do { 190 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) || 191 (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0)) 192 && (dmat->filter == NULL || 193 dmat->filter(dmat->filterarg, paddr) != 0)) 194 retval = 1; 195 196 dmat = dmat->parent; 197 } while (retval == 0 && dmat != NULL); 198 return (retval); 199 } 200 201 static __inline 202 bus_dma_segment_t * 203 bus_dma_tag_lock(bus_dma_tag_t tag, bus_dma_segment_t *cache) 204 { 205 if (tag->flags & BUS_DMA_PROTECTED) 206 return(tag->segments); 207 208 if (tag->nsegments <= BUS_DMA_CACHE_SEGMENTS) 209 return(cache); 210 spin_lock(&tag->spin); 211 return(tag->segments); 212 } 213 214 static __inline 215 void 216 bus_dma_tag_unlock(bus_dma_tag_t tag) 217 { 218 if (tag->flags & BUS_DMA_PROTECTED) 219 return; 220 221 if (tag->nsegments > BUS_DMA_CACHE_SEGMENTS) 222 spin_unlock(&tag->spin); 223 } 224 225 /* 226 * Allocate a device specific dma_tag. 227 */ 228 int 229 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 230 bus_size_t boundary, bus_addr_t lowaddr, 231 bus_addr_t highaddr, bus_dma_filter_t *filter, 232 void *filterarg, bus_size_t maxsize, int nsegments, 233 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat) 234 { 235 bus_dma_tag_t newtag; 236 int error = 0; 237 238 /* 239 * Sanity checks 240 */ 241 242 if (alignment == 0) 243 alignment = 1; 244 if (alignment & (alignment - 1)) 245 panic("alignment must be power of 2"); 246 247 if (boundary != 0) { 248 if (boundary & (boundary - 1)) 249 panic("boundary must be power of 2"); 250 if (boundary < maxsegsz) { 251 kprintf("boundary < maxsegsz:\n"); 252 print_backtrace(-1); 253 maxsegsz = boundary; 254 } 255 } 256 257 /* Return a NULL tag on failure */ 258 *dmat = NULL; 259 260 newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT | M_ZERO); 261 262 spin_init(&newtag->spin); 263 newtag->parent = parent; 264 newtag->alignment = alignment; 265 newtag->boundary = boundary; 266 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 267 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1); 268 newtag->filter = filter; 269 newtag->filterarg = filterarg; 270 newtag->maxsize = maxsize; 271 newtag->nsegments = nsegments; 272 newtag->maxsegsz = maxsegsz; 273 newtag->flags = flags; 274 newtag->ref_count = 1; /* Count ourself */ 275 newtag->map_count = 0; 276 newtag->segments = NULL; 277 newtag->bounce_zone = NULL; 278 279 /* Take into account any restrictions imposed by our parent tag */ 280 if (parent != NULL) { 281 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 282 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 283 284 if (newtag->boundary == 0) { 285 newtag->boundary = parent->boundary; 286 } else if (parent->boundary != 0) { 287 newtag->boundary = MIN(parent->boundary, 288 newtag->boundary); 289 } 290 291 #ifdef notyet 292 newtag->alignment = MAX(parent->alignment, newtag->alignment); 293 #endif 294 295 if (newtag->filter == NULL) { 296 /* 297 * Short circuit looking at our parent directly 298 * since we have encapsulated all of its information 299 */ 300 newtag->filter = parent->filter; 301 newtag->filterarg = parent->filterarg; 302 newtag->parent = parent->parent; 303 } 304 if (newtag->parent != NULL) 305 parent->ref_count++; 306 } 307 308 if (newtag->lowaddr < ptoa(Maxmem)) 309 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR; 310 if (bounce_alignment && newtag->alignment > 1 && 311 !(newtag->flags & BUS_DMA_ALIGNED)) 312 newtag->flags |= BUS_DMA_BOUNCE_ALIGN; 313 314 if ((newtag->flags & BUS_DMA_COULD_BOUNCE) && 315 (flags & BUS_DMA_ALLOCNOW) != 0) { 316 struct bounce_zone *bz; 317 318 /* Must bounce */ 319 320 error = alloc_bounce_zone(newtag); 321 if (error) 322 goto back; 323 bz = newtag->bounce_zone; 324 325 if ((newtag->flags & BUS_DMA_ALLOCALL) == 0 && 326 ptoa(bz->total_bpages) < maxsize) { 327 int pages; 328 329 if (flags & BUS_DMA_ONEBPAGE) { 330 pages = 1; 331 } else { 332 pages = atop(round_page(maxsize)) - 333 bz->total_bpages; 334 pages = MAX(pages, 1); 335 } 336 337 /* Add pages to our bounce pool */ 338 if (alloc_bounce_pages(newtag, pages, flags) < pages) 339 error = ENOMEM; 340 341 /* Performed initial allocation */ 342 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 343 } 344 } 345 back: 346 if (error) { 347 free_bounce_zone(newtag); 348 kfree(newtag, M_DEVBUF); 349 } else { 350 *dmat = newtag; 351 } 352 return error; 353 } 354 355 int 356 bus_dma_tag_destroy(bus_dma_tag_t dmat) 357 { 358 if (dmat != NULL) { 359 if (dmat->map_count != 0) 360 return (EBUSY); 361 362 while (dmat != NULL) { 363 bus_dma_tag_t parent; 364 365 parent = dmat->parent; 366 dmat->ref_count--; 367 if (dmat->ref_count == 0) { 368 free_bounce_zone(dmat); 369 if (dmat->segments != NULL) 370 kfree(dmat->segments, M_DEVBUF); 371 kfree(dmat, M_DEVBUF); 372 /* 373 * Last reference count, so 374 * release our reference 375 * count on our parent. 376 */ 377 dmat = parent; 378 } else 379 dmat = NULL; 380 } 381 } 382 return (0); 383 } 384 385 bus_size_t 386 bus_dma_tag_getmaxsize(bus_dma_tag_t tag) 387 { 388 return(tag->maxsize); 389 } 390 391 /* 392 * Allocate a handle for mapping from kva/uva/physical 393 * address space into bus device space. 394 */ 395 int 396 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 397 { 398 int error; 399 400 error = 0; 401 402 if (dmat->segments == NULL) { 403 KKASSERT(dmat->nsegments && dmat->nsegments < 16384); 404 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) * 405 dmat->nsegments, M_DEVBUF, M_INTWAIT); 406 } 407 408 if (dmat->flags & BUS_DMA_COULD_BOUNCE) { 409 struct bounce_zone *bz; 410 int maxpages; 411 412 /* Must bounce */ 413 414 if (dmat->bounce_zone == NULL) { 415 error = alloc_bounce_zone(dmat); 416 if (error) 417 return error; 418 } 419 bz = dmat->bounce_zone; 420 421 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO); 422 423 /* Initialize the new map */ 424 STAILQ_INIT(&((*mapp)->bpages)); 425 426 /* 427 * Attempt to add pages to our pool on a per-instance 428 * basis up to a sane limit. 429 */ 430 if (dmat->flags & BUS_DMA_ALLOCALL) { 431 maxpages = Maxmem - atop(dmat->lowaddr); 432 } else if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) { 433 maxpages = max_bounce_pages; 434 } else { 435 maxpages = MIN(max_bounce_pages, 436 Maxmem - atop(dmat->lowaddr)); 437 } 438 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 || 439 (dmat->map_count > 0 && bz->total_bpages < maxpages)) { 440 int pages; 441 442 if (flags & BUS_DMA_ONEBPAGE) { 443 pages = 1; 444 } else { 445 pages = atop(round_page(dmat->maxsize)); 446 pages = MIN(maxpages - bz->total_bpages, pages); 447 pages = MAX(pages, 1); 448 } 449 if (alloc_bounce_pages(dmat, pages, flags) < pages) 450 error = ENOMEM; 451 452 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 453 if (!error && 454 (dmat->flags & BUS_DMA_ALLOCALL) == 0) 455 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 456 } else { 457 error = 0; 458 } 459 } 460 } else { 461 *mapp = NULL; 462 } 463 if (!error) { 464 dmat->map_count++; 465 } else { 466 kfree(*mapp, M_DEVBUF); 467 *mapp = NULL; 468 } 469 return error; 470 } 471 472 /* 473 * Destroy a handle for mapping from kva/uva/physical 474 * address space into bus device space. 475 */ 476 int 477 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 478 { 479 if (map != NULL) { 480 if (STAILQ_FIRST(&map->bpages) != NULL) 481 return (EBUSY); 482 kfree(map, M_DEVBUF); 483 } 484 dmat->map_count--; 485 return (0); 486 } 487 488 static __inline bus_size_t 489 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify) 490 { 491 bus_size_t maxsize = 0; 492 uintptr_t vaddr = (uintptr_t)vaddr0; 493 494 if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) { 495 if (verify) 496 panic("boundary check failed\n"); 497 if (bootverbose) 498 kprintf("boundary check failed\n"); 499 maxsize = dmat->maxsize; 500 } 501 if (vaddr & (dmat->alignment - 1)) { 502 if (verify) 503 panic("alignment check failed\n"); 504 if (bootverbose) 505 kprintf("alignment check failed\n"); 506 if (dmat->maxsize < dmat->alignment) 507 maxsize = dmat->alignment; 508 else 509 maxsize = dmat->maxsize; 510 } 511 return maxsize; 512 } 513 514 /* 515 * Allocate a piece of memory that can be efficiently mapped into 516 * bus device space based on the constraints lited in the dma tag. 517 * 518 * mapp is degenerate. By definition this allocation should not require 519 * bounce buffers so do not allocate a dma map. 520 */ 521 int 522 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags, 523 bus_dmamap_t *mapp) 524 { 525 int mflags; 526 527 /* If we succeed, no mapping/bouncing will be required */ 528 *mapp = NULL; 529 530 if (dmat->segments == NULL) { 531 KKASSERT(dmat->nsegments < 16384); 532 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) * 533 dmat->nsegments, M_DEVBUF, M_INTWAIT); 534 } 535 536 if (flags & BUS_DMA_NOWAIT) 537 mflags = M_NOWAIT; 538 else 539 mflags = M_WAITOK; 540 if (flags & BUS_DMA_ZERO) 541 mflags |= M_ZERO; 542 543 if (BUS_DMAMEM_KMALLOC(dmat)) { 544 bus_size_t maxsize; 545 546 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags); 547 548 /* 549 * XXX 550 * Check whether the allocation 551 * - crossed a page boundary 552 * - was not aligned 553 * Retry with power-of-2 alignment in the above cases. 554 */ 555 maxsize = check_kmalloc(dmat, *vaddr, 0); 556 if (maxsize) { 557 kfree(*vaddr, M_DEVBUF); 558 *vaddr = kmalloc(maxsize, M_DEVBUF, 559 mflags | M_POWEROF2); 560 check_kmalloc(dmat, *vaddr, 1); 561 } 562 } else { 563 /* 564 * XXX Use Contigmalloc until it is merged into this facility 565 * and handles multi-seg allocations. Nobody is doing 566 * multi-seg allocations yet though. 567 */ 568 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags, 569 0ul, dmat->lowaddr, dmat->alignment, dmat->boundary); 570 } 571 if (*vaddr == NULL) 572 return (ENOMEM); 573 return (0); 574 } 575 576 /* 577 * Free a piece of memory and it's allociated dmamap, that was allocated 578 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 579 */ 580 void 581 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 582 { 583 /* 584 * dmamem does not need to be bounced, so the map should be 585 * NULL 586 */ 587 if (map != NULL) 588 panic("bus_dmamem_free: Invalid map freed"); 589 if (BUS_DMAMEM_KMALLOC(dmat)) 590 kfree(vaddr, M_DEVBUF); 591 else 592 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 593 } 594 595 static __inline vm_paddr_t 596 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr) 597 { 598 if (pmap) 599 return pmap_extract(pmap, vaddr); 600 else 601 return pmap_kextract(vaddr); 602 } 603 604 /* 605 * Utility function to load a linear buffer. lastaddrp holds state 606 * between invocations (for multiple-buffer loads). segp contains 607 * the segment following the starting one on entrace, and the ending 608 * segment on exit. first indicates if this is the first invocation 609 * of this function. 610 */ 611 static int 612 _bus_dmamap_load_buffer(bus_dma_tag_t dmat, 613 bus_dmamap_t map, 614 void *buf, bus_size_t buflen, 615 bus_dma_segment_t *segments, 616 int nsegments, 617 pmap_t pmap, 618 int flags, 619 vm_paddr_t *lastpaddrp, 620 int *segp, 621 int first) 622 { 623 vm_offset_t vaddr; 624 vm_paddr_t paddr, nextpaddr; 625 bus_dma_segment_t *sg; 626 bus_addr_t bmask; 627 int seg, error = 0; 628 629 if (map == NULL) 630 map = &nobounce_dmamap; 631 632 #ifdef INVARIANTS 633 if (dmat->flags & BUS_DMA_ALIGNED) 634 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0); 635 #endif 636 637 /* 638 * If we are being called during a callback, pagesneeded will 639 * be non-zero, so we can avoid doing the work twice. 640 */ 641 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) && 642 map != &nobounce_dmamap && map->pagesneeded == 0) { 643 vm_offset_t vendaddr; 644 645 /* 646 * Count the number of bounce pages 647 * needed in order to complete this transfer 648 */ 649 vaddr = (vm_offset_t)buf; 650 vendaddr = (vm_offset_t)buf + buflen; 651 652 while (vaddr < vendaddr) { 653 paddr = _bus_dma_extract(pmap, vaddr); 654 if (run_filter(dmat, paddr) != 0) 655 map->pagesneeded++; 656 vaddr += (PAGE_SIZE - (vaddr & PAGE_MASK)); 657 } 658 } 659 660 /* Reserve Necessary Bounce Pages */ 661 if (map->pagesneeded != 0) { 662 struct bounce_zone *bz; 663 664 bz = dmat->bounce_zone; 665 BZ_LOCK(bz); 666 if (flags & BUS_DMA_NOWAIT) { 667 if (reserve_bounce_pages(dmat, map, 0) != 0) { 668 BZ_UNLOCK(bz); 669 error = ENOMEM; 670 goto free_bounce; 671 } 672 } else { 673 if (reserve_bounce_pages(dmat, map, 1) != 0) { 674 /* Queue us for resources */ 675 map->dmat = dmat; 676 map->buf = buf; 677 map->buflen = buflen; 678 679 STAILQ_INSERT_TAIL( 680 &dmat->bounce_zone->bounce_map_waitinglist, 681 map, links); 682 BZ_UNLOCK(bz); 683 684 return (EINPROGRESS); 685 } 686 } 687 BZ_UNLOCK(bz); 688 } 689 690 KKASSERT(*segp >= 1 && *segp <= nsegments); 691 seg = *segp; 692 sg = &segments[seg - 1]; 693 694 vaddr = (vm_offset_t)buf; 695 nextpaddr = *lastpaddrp; 696 bmask = ~(dmat->boundary - 1); /* note: will be 0 if boundary is 0 */ 697 698 /* force at least one segment */ 699 do { 700 bus_size_t size; 701 702 /* 703 * Per-page main loop 704 */ 705 paddr = _bus_dma_extract(pmap, vaddr); 706 size = PAGE_SIZE - (paddr & PAGE_MASK); 707 if (size > buflen) 708 size = buflen; 709 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) { 710 /* 711 * note: this paddr has the same in-page offset 712 * as vaddr and thus the paddr above, so the 713 * size does not have to be recalculated 714 */ 715 paddr = add_bounce_page(dmat, map, vaddr, size); 716 } 717 718 /* 719 * Fill in the bus_dma_segment 720 */ 721 if (first) { 722 sg->ds_addr = paddr; 723 sg->ds_len = size; 724 first = 0; 725 } else if (paddr == nextpaddr) { 726 sg->ds_len += size; 727 } else { 728 sg++; 729 seg++; 730 if (seg > nsegments) 731 break; 732 sg->ds_addr = paddr; 733 sg->ds_len = size; 734 } 735 nextpaddr = paddr + size; 736 737 /* 738 * Handle maxsegsz and boundary issues with a nested loop 739 */ 740 for (;;) { 741 bus_size_t tmpsize; 742 743 /* 744 * Limit to the boundary and maximum segment size 745 */ 746 if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) { 747 tmpsize = dmat->boundary - 748 (sg->ds_addr & ~bmask); 749 if (tmpsize > dmat->maxsegsz) 750 tmpsize = dmat->maxsegsz; 751 KKASSERT(tmpsize < sg->ds_len); 752 } else if (sg->ds_len > dmat->maxsegsz) { 753 tmpsize = dmat->maxsegsz; 754 } else { 755 break; 756 } 757 758 /* 759 * Futz, split the data into a new segment. 760 */ 761 if (seg >= nsegments) 762 goto fail; 763 sg[1].ds_len = sg[0].ds_len - tmpsize; 764 sg[1].ds_addr = sg[0].ds_addr + tmpsize; 765 sg[0].ds_len = tmpsize; 766 sg++; 767 seg++; 768 } 769 770 /* 771 * Adjust for loop 772 */ 773 buflen -= size; 774 vaddr += size; 775 } while (buflen > 0); 776 fail: 777 if (buflen != 0) 778 error = EFBIG; 779 780 *segp = seg; 781 *lastpaddrp = nextpaddr; 782 783 free_bounce: 784 if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) && 785 map != &nobounce_dmamap) { 786 _bus_dmamap_unload(dmat, map); 787 return_bounce_pages(dmat, map); 788 } 789 return error; 790 } 791 792 /* 793 * Map the buffer buf into bus space using the dmamap map. 794 */ 795 int 796 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 797 bus_size_t buflen, bus_dmamap_callback_t *callback, 798 void *callback_arg, int flags) 799 { 800 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS]; 801 bus_dma_segment_t *segments; 802 vm_paddr_t lastaddr = 0; 803 int error, nsegs = 1; 804 805 if (map != NULL) { 806 /* 807 * XXX 808 * Follow old semantics. Once all of the callers are fixed, 809 * we should get rid of these internal flag "adjustment". 810 */ 811 flags &= ~BUS_DMA_NOWAIT; 812 flags |= BUS_DMA_WAITOK; 813 814 map->callback = callback; 815 map->callback_arg = callback_arg; 816 } 817 818 segments = bus_dma_tag_lock(dmat, cache_segments); 819 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, 820 segments, dmat->nsegments, 821 NULL, flags, &lastaddr, &nsegs, 1); 822 if (error == EINPROGRESS) { 823 KKASSERT((dmat->flags & 824 (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL)) != 825 (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL)); 826 827 if (dmat->flags & BUS_DMA_PROTECTED) 828 panic("protected dmamap callback will be defered"); 829 830 bus_dma_tag_unlock(dmat); 831 return error; 832 } 833 callback(callback_arg, segments, nsegs, error); 834 bus_dma_tag_unlock(dmat); 835 return 0; 836 } 837 838 /* 839 * Like _bus_dmamap_load(), but for mbufs. 840 */ 841 int 842 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 843 struct mbuf *m0, 844 bus_dmamap_callback2_t *callback, void *callback_arg, 845 int flags) 846 { 847 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS]; 848 bus_dma_segment_t *segments; 849 int nsegs, error; 850 851 /* 852 * XXX 853 * Follow old semantics. Once all of the callers are fixed, 854 * we should get rid of these internal flag "adjustment". 855 */ 856 flags &= ~BUS_DMA_WAITOK; 857 flags |= BUS_DMA_NOWAIT; 858 859 segments = bus_dma_tag_lock(dmat, cache_segments); 860 error = bus_dmamap_load_mbuf_segment(dmat, map, m0, 861 segments, dmat->nsegments, &nsegs, flags); 862 if (error) { 863 /* force "no valid mappings" in callback */ 864 callback(callback_arg, segments, 0, 865 0, error); 866 } else { 867 callback(callback_arg, segments, nsegs, 868 m0->m_pkthdr.len, error); 869 } 870 bus_dma_tag_unlock(dmat); 871 return error; 872 } 873 874 int 875 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map, 876 struct mbuf *m0, 877 bus_dma_segment_t *segs, int maxsegs, 878 int *nsegs, int flags) 879 { 880 int error; 881 882 M_ASSERTPKTHDR(m0); 883 884 KASSERT(maxsegs >= 1, ("invalid maxsegs %d", maxsegs)); 885 KASSERT(maxsegs <= dmat->nsegments, 886 ("%d too many segments, dmat only supports %d segments", 887 maxsegs, dmat->nsegments)); 888 KASSERT(flags & BUS_DMA_NOWAIT, 889 ("only BUS_DMA_NOWAIT is supported")); 890 891 if (m0->m_pkthdr.len <= dmat->maxsize) { 892 int first = 1; 893 vm_paddr_t lastaddr = 0; 894 struct mbuf *m; 895 896 *nsegs = 1; 897 error = 0; 898 for (m = m0; m != NULL && error == 0; m = m->m_next) { 899 if (m->m_len == 0) 900 continue; 901 902 error = _bus_dmamap_load_buffer(dmat, map, 903 m->m_data, m->m_len, 904 segs, maxsegs, 905 NULL, flags, &lastaddr, 906 nsegs, first); 907 if (error == ENOMEM && !first) { 908 /* 909 * Out of bounce pages due to too many 910 * fragments in the mbuf chain; return 911 * EFBIG instead. 912 */ 913 error = EFBIG; 914 } 915 first = 0; 916 } 917 #ifdef INVARIANTS 918 if (!error) 919 KKASSERT(*nsegs <= maxsegs && *nsegs >= 1); 920 #endif 921 } else { 922 *nsegs = 0; 923 error = EINVAL; 924 } 925 KKASSERT(error != EINPROGRESS); 926 return error; 927 } 928 929 /* 930 * Like _bus_dmamap_load(), but for uios. 931 */ 932 int 933 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 934 struct uio *uio, 935 bus_dmamap_callback2_t *callback, void *callback_arg, 936 int flags) 937 { 938 vm_paddr_t lastaddr; 939 int nsegs, error, first, i; 940 bus_size_t resid; 941 struct iovec *iov; 942 pmap_t pmap; 943 bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS]; 944 bus_dma_segment_t *segments; 945 bus_dma_segment_t *segs; 946 int nsegs_left; 947 948 if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS) 949 segments = cache_segments; 950 else 951 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments, 952 M_DEVBUF, M_WAITOK | M_ZERO); 953 954 /* 955 * XXX 956 * Follow old semantics. Once all of the callers are fixed, 957 * we should get rid of these internal flag "adjustment". 958 */ 959 flags &= ~BUS_DMA_WAITOK; 960 flags |= BUS_DMA_NOWAIT; 961 962 resid = (bus_size_t)uio->uio_resid; 963 iov = uio->uio_iov; 964 965 segs = segments; 966 nsegs_left = dmat->nsegments; 967 968 if (uio->uio_segflg == UIO_USERSPACE) { 969 struct thread *td; 970 971 td = uio->uio_td; 972 KASSERT(td != NULL && td->td_proc != NULL, 973 ("bus_dmamap_load_uio: USERSPACE but no proc")); 974 pmap = vmspace_pmap(td->td_proc->p_vmspace); 975 } else { 976 pmap = NULL; 977 } 978 979 error = 0; 980 nsegs = 1; 981 first = 1; 982 lastaddr = 0; 983 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 984 /* 985 * Now at the first iovec to load. Load each iovec 986 * until we have exhausted the residual count. 987 */ 988 bus_size_t minlen = 989 resid < iov[i].iov_len ? resid : iov[i].iov_len; 990 caddr_t addr = (caddr_t) iov[i].iov_base; 991 992 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen, 993 segs, nsegs_left, 994 pmap, flags, &lastaddr, &nsegs, first); 995 first = 0; 996 997 resid -= minlen; 998 if (error == 0) { 999 nsegs_left -= nsegs; 1000 segs += nsegs; 1001 } 1002 } 1003 1004 /* 1005 * Minimum one DMA segment, even if 0-length buffer. 1006 */ 1007 if (nsegs_left == dmat->nsegments) 1008 --nsegs_left; 1009 1010 if (error) { 1011 /* force "no valid mappings" in callback */ 1012 callback(callback_arg, segments, 0, 1013 0, error); 1014 } else { 1015 callback(callback_arg, segments, dmat->nsegments - nsegs_left, 1016 (bus_size_t)uio->uio_resid, error); 1017 } 1018 if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS) 1019 kfree(segments, M_DEVBUF); 1020 return error; 1021 } 1022 1023 /* 1024 * Release the mapping held by map. 1025 */ 1026 void 1027 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 1028 { 1029 struct bounce_page *bpage; 1030 1031 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 1032 STAILQ_REMOVE_HEAD(&map->bpages, links); 1033 free_bounce_page(dmat, bpage); 1034 } 1035 } 1036 1037 void 1038 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 1039 { 1040 struct bounce_page *bpage; 1041 1042 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 1043 /* 1044 * Handle data bouncing. We might also 1045 * want to add support for invalidating 1046 * the caches on broken hardware 1047 */ 1048 switch (op) { 1049 case BUS_DMASYNC_PREWRITE: 1050 while (bpage != NULL) { 1051 bcopy((void *)bpage->datavaddr, 1052 (void *)bpage->vaddr, 1053 bpage->datacount); 1054 bpage = STAILQ_NEXT(bpage, links); 1055 } 1056 dmat->bounce_zone->total_bounced++; 1057 break; 1058 1059 case BUS_DMASYNC_POSTREAD: 1060 while (bpage != NULL) { 1061 bcopy((void *)bpage->vaddr, 1062 (void *)bpage->datavaddr, 1063 bpage->datacount); 1064 bpage = STAILQ_NEXT(bpage, links); 1065 } 1066 dmat->bounce_zone->total_bounced++; 1067 break; 1068 1069 case BUS_DMASYNC_PREREAD: 1070 case BUS_DMASYNC_POSTWRITE: 1071 /* No-ops */ 1072 break; 1073 } 1074 } 1075 } 1076 1077 static int 1078 alloc_bounce_zone(bus_dma_tag_t dmat) 1079 { 1080 struct bounce_zone *bz, *new_bz; 1081 1082 KASSERT(dmat->bounce_zone == NULL, 1083 ("bounce zone was already assigned")); 1084 1085 new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO); 1086 1087 lwkt_gettoken(&bounce_zone_tok); 1088 1089 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) { 1090 /* 1091 * For shared bounce zone, check to see 1092 * if we already have a suitable zone 1093 */ 1094 STAILQ_FOREACH(bz, &bounce_zone_list, links) { 1095 if (dmat->alignment <= bz->alignment && 1096 dmat->lowaddr >= bz->lowaddr) { 1097 lwkt_reltoken(&bounce_zone_tok); 1098 1099 dmat->bounce_zone = bz; 1100 kfree(new_bz, M_DEVBUF); 1101 return 0; 1102 } 1103 } 1104 } 1105 bz = new_bz; 1106 1107 spin_init(&bz->spin); 1108 STAILQ_INIT(&bz->bounce_page_list); 1109 STAILQ_INIT(&bz->bounce_map_waitinglist); 1110 bz->free_bpages = 0; 1111 bz->reserved_bpages = 0; 1112 bz->active_bpages = 0; 1113 bz->lowaddr = dmat->lowaddr; 1114 bz->alignment = round_page(dmat->alignment); 1115 ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr); 1116 1117 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) { 1118 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount); 1119 busdma_zonecount++; 1120 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links); 1121 } else { 1122 ksnprintf(bz->zoneid, 8, "zone%d", busdma_priv_zonecount); 1123 busdma_priv_zonecount--; 1124 } 1125 1126 lwkt_reltoken(&bounce_zone_tok); 1127 1128 dmat->bounce_zone = bz; 1129 1130 sysctl_ctx_init(&bz->sysctl_ctx); 1131 bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx, 1132 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid, 1133 CTLFLAG_RD, 0, ""); 1134 if (bz->sysctl_tree == NULL) { 1135 sysctl_ctx_free(&bz->sysctl_ctx); 1136 return 0; /* XXX error code? */ 1137 } 1138 1139 SYSCTL_ADD_INT(&bz->sysctl_ctx, 1140 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1141 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0, 1142 "Total bounce pages"); 1143 SYSCTL_ADD_INT(&bz->sysctl_ctx, 1144 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1145 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0, 1146 "Free bounce pages"); 1147 SYSCTL_ADD_INT(&bz->sysctl_ctx, 1148 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1149 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0, 1150 "Reserved bounce pages"); 1151 SYSCTL_ADD_INT(&bz->sysctl_ctx, 1152 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1153 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0, 1154 "Active bounce pages"); 1155 SYSCTL_ADD_INT(&bz->sysctl_ctx, 1156 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1157 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0, 1158 "Total bounce requests"); 1159 SYSCTL_ADD_INT(&bz->sysctl_ctx, 1160 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1161 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0, 1162 "Total bounce requests that were deferred"); 1163 SYSCTL_ADD_INT(&bz->sysctl_ctx, 1164 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1165 "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0, 1166 "Total bounce page reservations that were failed"); 1167 SYSCTL_ADD_STRING(&bz->sysctl_ctx, 1168 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1169 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, ""); 1170 SYSCTL_ADD_INT(&bz->sysctl_ctx, 1171 SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO, 1172 "alignment", CTLFLAG_RD, &bz->alignment, 0, ""); 1173 1174 return 0; 1175 } 1176 1177 static int 1178 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags) 1179 { 1180 struct bounce_zone *bz = dmat->bounce_zone; 1181 int count = 0, mflags; 1182 1183 if (flags & BUS_DMA_NOWAIT) 1184 mflags = M_NOWAIT; 1185 else 1186 mflags = M_WAITOK; 1187 1188 while (numpages > 0) { 1189 struct bounce_page *bpage; 1190 1191 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO); 1192 1193 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 1194 mflags, 0ul, 1195 bz->lowaddr, 1196 bz->alignment, 0); 1197 if (bpage->vaddr == 0) { 1198 kfree(bpage, M_DEVBUF); 1199 break; 1200 } 1201 bpage->busaddr = pmap_kextract(bpage->vaddr); 1202 1203 BZ_LOCK(bz); 1204 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links); 1205 total_bounce_pages++; 1206 bz->total_bpages++; 1207 bz->free_bpages++; 1208 BZ_UNLOCK(bz); 1209 1210 count++; 1211 numpages--; 1212 } 1213 return count; 1214 } 1215 1216 static void 1217 free_bounce_pages_all(bus_dma_tag_t dmat) 1218 { 1219 struct bounce_zone *bz = dmat->bounce_zone; 1220 struct bounce_page *bpage; 1221 1222 BZ_LOCK(bz); 1223 1224 while ((bpage = STAILQ_FIRST(&bz->bounce_page_list)) != NULL) { 1225 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links); 1226 1227 KKASSERT(total_bounce_pages > 0); 1228 total_bounce_pages--; 1229 1230 KKASSERT(bz->total_bpages > 0); 1231 bz->total_bpages--; 1232 1233 KKASSERT(bz->free_bpages > 0); 1234 bz->free_bpages--; 1235 1236 BZ_UNLOCK(bz); 1237 contigfree((void *)bpage->vaddr, PAGE_SIZE, M_DEVBUF); 1238 kfree(bpage, M_DEVBUF); 1239 BZ_LOCK(bz); 1240 } 1241 if (bz->total_bpages) { 1242 kprintf("#%d bounce pages are still in use\n", 1243 bz->total_bpages); 1244 print_backtrace(-1); 1245 } 1246 1247 BZ_UNLOCK(bz); 1248 } 1249 1250 static void 1251 free_bounce_zone(bus_dma_tag_t dmat) 1252 { 1253 struct bounce_zone *bz = dmat->bounce_zone; 1254 1255 if (bz == NULL) 1256 return; 1257 1258 if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) 1259 return; 1260 1261 free_bounce_pages_all(dmat); 1262 dmat->bounce_zone = NULL; 1263 1264 if (bz->sysctl_tree != NULL) 1265 sysctl_ctx_free(&bz->sysctl_ctx); 1266 kfree(bz, M_DEVBUF); 1267 } 1268 1269 /* Assume caller holds bounce zone spinlock */ 1270 static int 1271 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 1272 { 1273 struct bounce_zone *bz = dmat->bounce_zone; 1274 int pages; 1275 1276 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved); 1277 if (!commit && map->pagesneeded > (map->pagesreserved + pages)) { 1278 bz->reserve_failed++; 1279 return (map->pagesneeded - (map->pagesreserved + pages)); 1280 } 1281 1282 bz->free_bpages -= pages; 1283 1284 bz->reserved_bpages += pages; 1285 KKASSERT(bz->reserved_bpages <= bz->total_bpages); 1286 1287 map->pagesreserved += pages; 1288 pages = map->pagesneeded - map->pagesreserved; 1289 1290 return pages; 1291 } 1292 1293 static void 1294 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map) 1295 { 1296 struct bounce_zone *bz = dmat->bounce_zone; 1297 int reserved = map->pagesreserved; 1298 bus_dmamap_t wait_map; 1299 1300 map->pagesreserved = 0; 1301 map->pagesneeded = 0; 1302 1303 if (reserved == 0) 1304 return; 1305 1306 BZ_LOCK(bz); 1307 1308 bz->free_bpages += reserved; 1309 KKASSERT(bz->free_bpages <= bz->total_bpages); 1310 1311 KKASSERT(bz->reserved_bpages >= reserved); 1312 bz->reserved_bpages -= reserved; 1313 1314 wait_map = get_map_waiting(dmat); 1315 1316 BZ_UNLOCK(bz); 1317 1318 if (wait_map != NULL) 1319 add_map_callback(map); 1320 } 1321 1322 static bus_addr_t 1323 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 1324 bus_size_t size) 1325 { 1326 struct bounce_zone *bz = dmat->bounce_zone; 1327 struct bounce_page *bpage; 1328 1329 KASSERT(map->pagesneeded > 0, ("map doesn't need any pages")); 1330 map->pagesneeded--; 1331 1332 KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages")); 1333 map->pagesreserved--; 1334 1335 BZ_LOCK(bz); 1336 1337 bpage = STAILQ_FIRST(&bz->bounce_page_list); 1338 KASSERT(bpage != NULL, ("free page list is empty")); 1339 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links); 1340 1341 KKASSERT(bz->reserved_bpages > 0); 1342 bz->reserved_bpages--; 1343 1344 bz->active_bpages++; 1345 KKASSERT(bz->active_bpages <= bz->total_bpages); 1346 1347 BZ_UNLOCK(bz); 1348 1349 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) { 1350 /* Page offset needs to be preserved. */ 1351 bpage->vaddr |= vaddr & PAGE_MASK; 1352 bpage->busaddr |= vaddr & PAGE_MASK; 1353 } 1354 1355 bpage->datavaddr = vaddr; 1356 bpage->datacount = size; 1357 STAILQ_INSERT_TAIL(&map->bpages, bpage, links); 1358 return bpage->busaddr; 1359 } 1360 1361 static void 1362 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 1363 { 1364 struct bounce_zone *bz = dmat->bounce_zone; 1365 bus_dmamap_t map; 1366 1367 bpage->datavaddr = 0; 1368 bpage->datacount = 0; 1369 1370 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) { 1371 /* 1372 * Reset the bounce page to start at offset 0. Other uses 1373 * of this bounce page may need to store a full page of 1374 * data and/or assume it starts on a page boundary. 1375 */ 1376 bpage->vaddr &= ~PAGE_MASK; 1377 bpage->busaddr &= ~PAGE_MASK; 1378 } 1379 1380 BZ_LOCK(bz); 1381 1382 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links); 1383 1384 bz->free_bpages++; 1385 KKASSERT(bz->free_bpages <= bz->total_bpages); 1386 1387 KKASSERT(bz->active_bpages > 0); 1388 bz->active_bpages--; 1389 1390 map = get_map_waiting(dmat); 1391 1392 BZ_UNLOCK(bz); 1393 1394 if (map != NULL) 1395 add_map_callback(map); 1396 } 1397 1398 /* Assume caller holds bounce zone spinlock */ 1399 static bus_dmamap_t 1400 get_map_waiting(bus_dma_tag_t dmat) 1401 { 1402 struct bounce_zone *bz = dmat->bounce_zone; 1403 bus_dmamap_t map; 1404 1405 map = STAILQ_FIRST(&bz->bounce_map_waitinglist); 1406 if (map != NULL) { 1407 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 1408 STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links); 1409 bz->total_deferred++; 1410 } else { 1411 map = NULL; 1412 } 1413 } 1414 return map; 1415 } 1416 1417 static void 1418 add_map_callback(bus_dmamap_t map) 1419 { 1420 spin_lock(&bounce_map_list_spin); 1421 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links); 1422 busdma_swi_pending = 1; 1423 setsoftvm(); 1424 spin_unlock(&bounce_map_list_spin); 1425 } 1426 1427 void 1428 busdma_swi(void) 1429 { 1430 bus_dmamap_t map; 1431 1432 spin_lock(&bounce_map_list_spin); 1433 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 1434 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 1435 spin_unlock(&bounce_map_list_spin); 1436 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 1437 map->callback, map->callback_arg, /*flags*/0); 1438 spin_lock(&bounce_map_list_spin); 1439 } 1440 spin_unlock(&bounce_map_list_spin); 1441 } 1442