busdma_machdep.c revision 95076
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: head/sys/i386/i386/busdma_machdep.c 95076 2002-04-19 22:58:09Z alfred $ 27 */ 28 29#include <sys/param.h> 30#include <sys/systm.h> 31#include <sys/malloc.h> 32#include <sys/bus.h> 33#include <sys/interrupt.h> 34#include <sys/lock.h> 35#include <sys/proc.h> 36#include <sys/mutex.h> 37 38#include <vm/vm.h> 39#include <vm/vm_page.h> 40 41#include <machine/bus.h> 42#include <machine/md_var.h> 43 44#define MAX(a,b) (((a) > (b)) ? (a) : (b)) 45#define MIN(a,b) (((a) < (b)) ? (a) : (b)) 46#define MAX_BPAGES 128 47 48struct bus_dma_tag { 49 bus_dma_tag_t parent; 50 bus_size_t alignment; 51 bus_size_t boundary; 52 bus_addr_t lowaddr; 53 bus_addr_t highaddr; 54 bus_dma_filter_t *filter; 55 void *filterarg; 56 bus_size_t maxsize; 57 u_int nsegments; 58 bus_size_t maxsegsz; 59 int flags; 60 int ref_count; 61 int map_count; 62}; 63 64struct bounce_page { 65 vm_offset_t vaddr; /* kva of bounce buffer */ 66 bus_addr_t busaddr; /* Physical address */ 67 vm_offset_t datavaddr; /* kva of client data */ 68 bus_size_t datacount; /* client data count */ 69 STAILQ_ENTRY(bounce_page) links; 70}; 71 72int busdma_swi_pending; 73 74static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 75static int free_bpages; 76static int reserved_bpages; 77static int active_bpages; 78static int total_bpages; 79static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR; 80 81struct bus_dmamap { 82 struct bp_list bpages; 83 int pagesneeded; 84 int pagesreserved; 85 bus_dma_tag_t dmat; 86 void *buf; /* unmapped buffer pointer */ 87 bus_size_t buflen; /* unmapped buffer length */ 88 bus_dmamap_callback_t *callback; 89 void *callback_arg; 90 STAILQ_ENTRY(bus_dmamap) links; 91}; 92 93static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 94static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 95static struct bus_dmamap nobounce_dmamap; 96 97static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 98static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map); 99static vm_offset_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 100 vm_offset_t vaddr, bus_size_t size); 101static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 102static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 103 104/* 105 * Return true if a match is made. 106 * 107 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 108 * 109 * If paddr is within the bounds of the dma tag then call the filter callback 110 * to check for a match, if there is no filter callback then assume a match. 111 */ 112static __inline int 113run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 114{ 115 int retval; 116 117 retval = 0; 118 do { 119 if (paddr > dmat->lowaddr 120 && paddr <= dmat->highaddr 121 && (dmat->filter == NULL 122 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 123 retval = 1; 124 125 dmat = dmat->parent; 126 } while (retval == 0 && dmat != NULL); 127 return (retval); 128} 129 130#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 131/* 132 * Allocate a device specific dma_tag. 133 */ 134int 135bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 136 bus_size_t boundary, bus_addr_t lowaddr, 137 bus_addr_t highaddr, bus_dma_filter_t *filter, 138 void *filterarg, bus_size_t maxsize, int nsegments, 139 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat) 140{ 141 bus_dma_tag_t newtag; 142 int error = 0; 143 144 /* Return a NULL tag on failure */ 145 *dmat = NULL; 146 147 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT); 148 if (newtag == NULL) 149 return (ENOMEM); 150 151 newtag->parent = parent; 152 newtag->alignment = alignment; 153 newtag->boundary = boundary; 154 newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1); 155 newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1); 156 newtag->filter = filter; 157 newtag->filterarg = filterarg; 158 newtag->maxsize = maxsize; 159 newtag->nsegments = nsegments; 160 newtag->maxsegsz = maxsegsz; 161 newtag->flags = flags; 162 newtag->ref_count = 1; /* Count ourself */ 163 newtag->map_count = 0; 164 165 /* Take into account any restrictions imposed by our parent tag */ 166 if (parent != NULL) { 167 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 168 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 169 /* 170 * XXX Not really correct??? Probably need to honor boundary 171 * all the way up the inheritence chain. 172 */ 173 newtag->boundary = MAX(parent->boundary, newtag->boundary); 174 if (newtag->filter == NULL) { 175 /* 176 * Short circuit looking at our parent directly 177 * since we have encapsulated all of its information 178 */ 179 newtag->filter = parent->filter; 180 newtag->filterarg = parent->filterarg; 181 newtag->parent = parent->parent; 182 } 183 if (newtag->parent != NULL) { 184 parent->ref_count++; 185 } 186 } 187 188 if (newtag->lowaddr < ptoa(Maxmem) && (flags & BUS_DMA_ALLOCNOW) != 0) { 189 /* Must bounce */ 190 191 if (lowaddr > bounce_lowaddr) { 192 /* 193 * Go through the pool and kill any pages 194 * that don't reside below lowaddr. 195 */ 196 panic("bus_dma_tag_create: page reallocation " 197 "not implemented"); 198 } 199 if (ptoa(total_bpages) < maxsize) { 200 int pages; 201 202 pages = atop(maxsize) - total_bpages; 203 204 /* Add pages to our bounce pool */ 205 if (alloc_bounce_pages(newtag, pages) < pages) 206 error = ENOMEM; 207 } 208 /* Performed initial allocation */ 209 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 210 } 211 212 if (error != 0) { 213 free(newtag, M_DEVBUF); 214 } else { 215 *dmat = newtag; 216 } 217 return (error); 218} 219 220int 221bus_dma_tag_destroy(bus_dma_tag_t dmat) 222{ 223 if (dmat != NULL) { 224 225 if (dmat->map_count != 0) 226 return (EBUSY); 227 228 while (dmat != NULL) { 229 bus_dma_tag_t parent; 230 231 parent = dmat->parent; 232 dmat->ref_count--; 233 if (dmat->ref_count == 0) { 234 free(dmat, M_DEVBUF); 235 /* 236 * Last reference count, so 237 * release our reference 238 * count on our parent. 239 */ 240 dmat = parent; 241 } else 242 dmat = NULL; 243 } 244 } 245 return (0); 246} 247 248/* 249 * Allocate a handle for mapping from kva/uva/physical 250 * address space into bus device space. 251 */ 252int 253bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 254{ 255 int error; 256 257 error = 0; 258 259 if (dmat->lowaddr < ptoa(Maxmem)) { 260 /* Must bounce */ 261 int maxpages; 262 263 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 264 M_NOWAIT | M_ZERO); 265 if (*mapp == NULL) 266 return (ENOMEM); 267 268 /* Initialize the new map */ 269 STAILQ_INIT(&((*mapp)->bpages)); 270 271 /* 272 * Attempt to add pages to our pool on a per-instance 273 * basis up to a sane limit. 274 */ 275 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr)); 276 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 277 || (dmat->map_count > 0 278 && total_bpages < maxpages)) { 279 int pages; 280 281 if (dmat->lowaddr > bounce_lowaddr) { 282 /* 283 * Go through the pool and kill any pages 284 * that don't reside below lowaddr. 285 */ 286 panic("bus_dmamap_create: page reallocation " 287 "not implemented"); 288 } 289 pages = atop(dmat->maxsize); 290 pages = MIN(maxpages - total_bpages, pages); 291 error = alloc_bounce_pages(dmat, pages); 292 293 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 294 if (error == 0) 295 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 296 } else { 297 error = 0; 298 } 299 } 300 } else { 301 *mapp = NULL; 302 } 303 if (error == 0) 304 dmat->map_count++; 305 return (error); 306} 307 308/* 309 * Destroy a handle for mapping from kva/uva/physical 310 * address space into bus device space. 311 */ 312int 313bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 314{ 315 if (map != NULL) { 316 if (STAILQ_FIRST(&map->bpages) != NULL) 317 return (EBUSY); 318 free(map, M_DEVBUF); 319 } 320 dmat->map_count--; 321 return (0); 322} 323 324 325/* 326 * Allocate a piece of memory that can be efficiently mapped into 327 * bus device space based on the constraints lited in the dma tag. 328 * A dmamap to for use with dmamap_load is also allocated. 329 */ 330int 331bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 332 bus_dmamap_t *mapp) 333{ 334 /* If we succeed, no mapping/bouncing will be required */ 335 *mapp = NULL; 336 337 if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem)) { 338 *vaddr = malloc(dmat->maxsize, M_DEVBUF, 339 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK); 340 } else { 341 /* 342 * XXX Use Contigmalloc until it is merged into this facility 343 * and handles multi-seg allocations. Nobody is doing 344 * multi-seg allocations yet though. 345 */ 346 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, 347 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK, 348 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 349 dmat->boundary); 350 } 351 if (*vaddr == NULL) 352 return (ENOMEM); 353 return (0); 354} 355 356/* 357 * Free a piece of memory and it's allociated dmamap, that was allocated 358 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 359 */ 360void 361bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 362{ 363 /* 364 * dmamem does not need to be bounced, so the map should be 365 * NULL 366 */ 367 if (map != NULL) 368 panic("bus_dmamem_free: Invalid map freed\n"); 369 if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem)) 370 free(vaddr, M_DEVBUF); 371 else 372 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 373} 374 375#define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1) 376 377/* 378 * Map the buffer buf into bus space using the dmamap map. 379 */ 380int 381bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 382 bus_size_t buflen, bus_dmamap_callback_t *callback, 383 void *callback_arg, int flags) 384{ 385 vm_offset_t vaddr; 386 vm_offset_t paddr; 387#ifdef __GNUC__ 388 bus_dma_segment_t dm_segments[dmat->nsegments]; 389#else 390 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 391#endif 392 bus_dma_segment_t *sg; 393 int seg; 394 int error; 395 vm_offset_t nextpaddr; 396 397 if (map == NULL) 398 map = &nobounce_dmamap; 399 400 error = 0; 401 /* 402 * If we are being called during a callback, pagesneeded will 403 * be non-zero, so we can avoid doing the work twice. 404 */ 405 if (dmat->lowaddr < ptoa(Maxmem) && map->pagesneeded == 0) { 406 vm_offset_t vendaddr; 407 408 /* 409 * Count the number of bounce pages 410 * needed in order to complete this transfer 411 */ 412 vaddr = trunc_page((vm_offset_t)buf); 413 vendaddr = (vm_offset_t)buf + buflen; 414 415 while (vaddr < vendaddr) { 416 paddr = pmap_kextract(vaddr); 417 if (run_filter(dmat, paddr) != 0) { 418 419 map->pagesneeded++; 420 } 421 vaddr += PAGE_SIZE; 422 } 423 } 424 425 /* Reserve Necessary Bounce Pages */ 426 if (map->pagesneeded != 0) { 427 int s; 428 429 s = splhigh(); 430 if (reserve_bounce_pages(dmat, map) != 0) { 431 432 /* Queue us for resources */ 433 map->dmat = dmat; 434 map->buf = buf; 435 map->buflen = buflen; 436 map->callback = callback; 437 map->callback_arg = callback_arg; 438 439 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links); 440 splx(s); 441 442 return (EINPROGRESS); 443 } 444 splx(s); 445 } 446 447 vaddr = (vm_offset_t)buf; 448 sg = &dm_segments[0]; 449 seg = 1; 450 sg->ds_len = 0; 451 452 nextpaddr = 0; 453 do { 454 bus_size_t size; 455 456 paddr = pmap_kextract(vaddr); 457 size = PAGE_SIZE - (paddr & PAGE_MASK); 458 if (size > buflen) 459 size = buflen; 460 461 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) { 462 paddr = add_bounce_page(dmat, map, vaddr, size); 463 } 464 465 if (sg->ds_len == 0) { 466 sg->ds_addr = paddr; 467 sg->ds_len = size; 468 } else if (paddr == nextpaddr) { 469 sg->ds_len += size; 470 } else { 471 /* Go to the next segment */ 472 sg++; 473 seg++; 474 if (seg > dmat->nsegments) 475 break; 476 sg->ds_addr = paddr; 477 sg->ds_len = size; 478 } 479 vaddr += size; 480 nextpaddr = paddr + size; 481 buflen -= size; 482 483 } while (buflen > 0); 484 485 if (buflen != 0) { 486 printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n", 487 (u_long)buflen); 488 error = EFBIG; 489 } 490 491 (*callback)(callback_arg, dm_segments, seg, error); 492 493 return (0); 494} 495 496/* 497 * Release the mapping held by map. 498 */ 499void 500_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 501{ 502 struct bounce_page *bpage; 503 504 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 505 STAILQ_REMOVE_HEAD(&map->bpages, links); 506 free_bounce_page(dmat, bpage); 507 } 508} 509 510void 511_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 512{ 513 struct bounce_page *bpage; 514 515 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 516 517 /* 518 * Handle data bouncing. We might also 519 * want to add support for invalidating 520 * the caches on broken hardware 521 */ 522 switch (op) { 523 case BUS_DMASYNC_PREWRITE: 524 while (bpage != NULL) { 525 bcopy((void *)bpage->datavaddr, 526 (void *)bpage->vaddr, 527 bpage->datacount); 528 bpage = STAILQ_NEXT(bpage, links); 529 } 530 break; 531 532 case BUS_DMASYNC_POSTREAD: 533 while (bpage != NULL) { 534 bcopy((void *)bpage->vaddr, 535 (void *)bpage->datavaddr, 536 bpage->datacount); 537 bpage = STAILQ_NEXT(bpage, links); 538 } 539 break; 540 case BUS_DMASYNC_PREREAD: 541 case BUS_DMASYNC_POSTWRITE: 542 /* No-ops */ 543 break; 544 } 545 } 546} 547 548static int 549alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 550{ 551 int count; 552 553 count = 0; 554 if (total_bpages == 0) { 555 STAILQ_INIT(&bounce_page_list); 556 STAILQ_INIT(&bounce_map_waitinglist); 557 STAILQ_INIT(&bounce_map_callbacklist); 558 } 559 560 while (numpages > 0) { 561 struct bounce_page *bpage; 562 int s; 563 564 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 565 M_NOWAIT | M_ZERO); 566 567 if (bpage == NULL) 568 break; 569 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 570 M_NOWAIT, 0ul, 571 dmat->lowaddr, 572 PAGE_SIZE, 573 0); 574 if (bpage->vaddr == NULL) { 575 free(bpage, M_DEVBUF); 576 break; 577 } 578 bpage->busaddr = pmap_kextract(bpage->vaddr); 579 s = splhigh(); 580 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links); 581 total_bpages++; 582 free_bpages++; 583 splx(s); 584 count++; 585 numpages--; 586 } 587 return (count); 588} 589 590static int 591reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map) 592{ 593 int pages; 594 595 pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved); 596 free_bpages -= pages; 597 reserved_bpages += pages; 598 map->pagesreserved += pages; 599 pages = map->pagesneeded - map->pagesreserved; 600 601 return (pages); 602} 603 604static vm_offset_t 605add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 606 bus_size_t size) 607{ 608 int s; 609 struct bounce_page *bpage; 610 611 if (map->pagesneeded == 0) 612 panic("add_bounce_page: map doesn't need any pages"); 613 map->pagesneeded--; 614 615 if (map->pagesreserved == 0) 616 panic("add_bounce_page: map doesn't need any pages"); 617 map->pagesreserved--; 618 619 s = splhigh(); 620 bpage = STAILQ_FIRST(&bounce_page_list); 621 if (bpage == NULL) 622 panic("add_bounce_page: free page list is empty"); 623 624 STAILQ_REMOVE_HEAD(&bounce_page_list, links); 625 reserved_bpages--; 626 active_bpages++; 627 splx(s); 628 629 bpage->datavaddr = vaddr; 630 bpage->datacount = size; 631 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 632 return (bpage->busaddr); 633} 634 635static void 636free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 637{ 638 int s; 639 struct bus_dmamap *map; 640 641 bpage->datavaddr = 0; 642 bpage->datacount = 0; 643 644 s = splhigh(); 645 STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links); 646 free_bpages++; 647 active_bpages--; 648 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 649 if (reserve_bounce_pages(map->dmat, map) == 0) { 650 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 651 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 652 map, links); 653 busdma_swi_pending = 1; 654 swi_sched(vm_ih, 0); 655 } 656 } 657 splx(s); 658} 659 660void 661busdma_swi(void) 662{ 663 int s; 664 struct bus_dmamap *map; 665 666 s = splhigh(); 667 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 668 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 669 splx(s); 670 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 671 map->callback, map->callback_arg, /*flags*/0); 672 s = splhigh(); 673 } 674 splx(s); 675} 676