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