busdma_machdep.c revision 115343
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 115343 2003-05-27 04:59:59Z scottl $ 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/kernel.h> 35#include <sys/lock.h> 36#include <sys/proc.h> 37#include <sys/mutex.h> 38#include <sys/mbuf.h> 39#include <sys/uio.h> 40 41#include <vm/vm.h> 42#include <vm/vm_page.h> 43#include <vm/vm_map.h> 44 45#include <machine/atomic.h> 46#include <machine/bus.h> 47#include <machine/md_var.h> 48 49#define MAX_BPAGES 512 50 51struct bus_dma_tag { 52 bus_dma_tag_t parent; 53 bus_size_t alignment; 54 bus_size_t boundary; 55 bus_addr_t lowaddr; 56 bus_addr_t highaddr; 57 bus_dma_filter_t *filter; 58 void *filterarg; 59 bus_size_t maxsize; 60 u_int nsegments; 61 bus_size_t maxsegsz; 62 int flags; 63 int ref_count; 64 int map_count; 65}; 66 67struct bounce_page { 68 vm_offset_t vaddr; /* kva of bounce buffer */ 69 bus_addr_t busaddr; /* Physical address */ 70 vm_offset_t datavaddr; /* kva of client data */ 71 bus_size_t datacount; /* client data count */ 72 STAILQ_ENTRY(bounce_page) links; 73}; 74 75int busdma_swi_pending; 76 77static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 78static int free_bpages; 79static int reserved_bpages; 80static int active_bpages; 81static int total_bpages; 82static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR; 83 84struct bus_dmamap { 85 struct bp_list bpages; 86 int pagesneeded; 87 int pagesreserved; 88 bus_dma_tag_t dmat; 89 void *buf; /* unmapped buffer pointer */ 90 bus_size_t buflen; /* unmapped buffer length */ 91 bus_dmamap_callback_t *callback; 92 void *callback_arg; 93 STAILQ_ENTRY(bus_dmamap) links; 94}; 95 96static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 97static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 98static struct bus_dmamap nobounce_dmamap; 99 100static void init_bounce_pages(void *dummy); 101static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 102static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, 103 int commit); 104static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 105 vm_offset_t vaddr, bus_size_t size); 106static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 107static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 108 109/* To protect all the the bounce pages related lists and data. */ 110static struct mtx bounce_lock; 111 112/* 113 * Return true if a match is made. 114 * 115 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 116 * 117 * If paddr is within the bounds of the dma tag then call the filter callback 118 * to check for a match, if there is no filter callback then assume a match. 119 */ 120static __inline int 121run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 122{ 123 int retval; 124 125 retval = 0; 126 do { 127 if (paddr > dmat->lowaddr 128 && paddr <= dmat->highaddr 129 && (dmat->filter == NULL 130 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 131 retval = 1; 132 133 dmat = dmat->parent; 134 } while (retval == 0 && dmat != NULL); 135 return (retval); 136} 137 138#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 139/* 140 * Allocate a device specific dma_tag. 141 */ 142int 143bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 144 bus_size_t boundary, bus_addr_t lowaddr, 145 bus_addr_t highaddr, bus_dma_filter_t *filter, 146 void *filterarg, bus_size_t maxsize, int nsegments, 147 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat) 148{ 149 bus_dma_tag_t newtag; 150 int error = 0; 151 152 /* Return a NULL tag on failure */ 153 *dmat = NULL; 154 155 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT); 156 if (newtag == NULL) 157 return (ENOMEM); 158 159 newtag->parent = parent; 160 newtag->alignment = alignment; 161 newtag->boundary = boundary; 162 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 163 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + 164 (PAGE_SIZE - 1); 165 newtag->filter = filter; 166 newtag->filterarg = filterarg; 167 newtag->maxsize = maxsize; 168 newtag->nsegments = nsegments; 169 newtag->maxsegsz = maxsegsz; 170 newtag->flags = flags; 171 newtag->ref_count = 1; /* Count ourself */ 172 newtag->map_count = 0; 173 174 /* Take into account any restrictions imposed by our parent tag */ 175 if (parent != NULL) { 176 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 177 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 178 /* 179 * XXX Not really correct??? Probably need to honor boundary 180 * all the way up the inheritence chain. 181 */ 182 newtag->boundary = MAX(parent->boundary, newtag->boundary); 183 if (newtag->filter == NULL) { 184 /* 185 * Short circuit looking at our parent directly 186 * since we have encapsulated all of its information 187 */ 188 newtag->filter = parent->filter; 189 newtag->filterarg = parent->filterarg; 190 newtag->parent = parent->parent; 191 } 192 if (newtag->parent != NULL) 193 atomic_add_int(&parent->ref_count, 1); 194 } 195 196 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) && 197 (flags & BUS_DMA_ALLOCNOW) != 0) { 198 /* Must bounce */ 199 200 if (lowaddr > bounce_lowaddr) { 201 /* 202 * Go through the pool and kill any pages 203 * that don't reside below lowaddr. 204 */ 205 panic("bus_dma_tag_create: page reallocation " 206 "not implemented"); 207 } 208 if (ptoa(total_bpages) < maxsize) { 209 int pages; 210 211 pages = atop(maxsize) - total_bpages; 212 213 /* Add pages to our bounce pool */ 214 if (alloc_bounce_pages(newtag, pages) < pages) 215 error = ENOMEM; 216 } 217 /* Performed initial allocation */ 218 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 219 } 220 221 if (error != 0) { 222 free(newtag, M_DEVBUF); 223 } else { 224 *dmat = newtag; 225 } 226 return (error); 227} 228 229int 230bus_dma_tag_destroy(bus_dma_tag_t dmat) 231{ 232 if (dmat != NULL) { 233 234 if (dmat->map_count != 0) 235 return (EBUSY); 236 237 while (dmat != NULL) { 238 bus_dma_tag_t parent; 239 240 parent = dmat->parent; 241 atomic_subtract_int(&dmat->ref_count, 1); 242 if (dmat->ref_count == 0) { 243 free(dmat, M_DEVBUF); 244 /* 245 * Last reference count, so 246 * release our reference 247 * count on our parent. 248 */ 249 dmat = parent; 250 } else 251 dmat = NULL; 252 } 253 } 254 return (0); 255} 256 257/* 258 * Allocate a handle for mapping from kva/uva/physical 259 * address space into bus device space. 260 */ 261int 262bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 263{ 264 int error; 265 266 error = 0; 267 268 if (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)) { 269 /* Must bounce */ 270 int maxpages; 271 272 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 273 M_NOWAIT | M_ZERO); 274 if (*mapp == NULL) 275 return (ENOMEM); 276 277 /* Initialize the new map */ 278 STAILQ_INIT(&((*mapp)->bpages)); 279 280 /* 281 * Attempt to add pages to our pool on a per-instance 282 * basis up to a sane limit. 283 */ 284 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr)); 285 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 286 || (dmat->map_count > 0 287 && total_bpages < maxpages)) { 288 int pages; 289 290 if (dmat->lowaddr > bounce_lowaddr) { 291 /* 292 * Go through the pool and kill any pages 293 * that don't reside below lowaddr. 294 */ 295 panic("bus_dmamap_create: page reallocation " 296 "not implemented"); 297 } 298 pages = MAX(atop(dmat->maxsize), 1); 299 pages = MIN(maxpages - total_bpages, pages); 300 if (alloc_bounce_pages(dmat, pages) < pages) 301 error = ENOMEM; 302 303 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 304 if (error == 0) 305 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 306 } else { 307 error = 0; 308 } 309 } 310 } else { 311 *mapp = NULL; 312 } 313 if (error == 0) 314 dmat->map_count++; 315 return (error); 316} 317 318/* 319 * Destroy a handle for mapping from kva/uva/physical 320 * address space into bus device space. 321 */ 322int 323bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 324{ 325 if (map != NULL) { 326 if (STAILQ_FIRST(&map->bpages) != NULL) 327 return (EBUSY); 328 free(map, M_DEVBUF); 329 } 330 dmat->map_count--; 331 return (0); 332} 333 334 335/* 336 * Allocate a piece of memory that can be efficiently mapped into 337 * bus device space based on the constraints lited in the dma tag. 338 * A dmamap to for use with dmamap_load is also allocated. 339 */ 340int 341bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 342 bus_dmamap_t *mapp) 343{ 344 /* If we succeed, no mapping/bouncing will be required */ 345 *mapp = NULL; 346 347 if ((dmat->maxsize <= PAGE_SIZE) && 348 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 349 *vaddr = malloc(dmat->maxsize, M_DEVBUF, 350 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK); 351 } else { 352 /* 353 * XXX Use Contigmalloc until it is merged into this facility 354 * and handles multi-seg allocations. Nobody is doing 355 * multi-seg allocations yet though. 356 */ 357 mtx_lock(&Giant); 358 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, 359 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK, 360 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 361 dmat->boundary); 362 mtx_unlock(&Giant); 363 } 364 if (*vaddr == NULL) 365 return (ENOMEM); 366 return (0); 367} 368 369/* 370 * Free a piece of memory and it's allociated dmamap, that was allocated 371 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 372 */ 373void 374bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 375{ 376 /* 377 * dmamem does not need to be bounced, so the map should be 378 * NULL 379 */ 380 if (map != NULL) 381 panic("bus_dmamem_free: Invalid map freed\n"); 382 if ((dmat->maxsize <= PAGE_SIZE) 383 && dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 384 free(vaddr, M_DEVBUF); 385 else { 386 mtx_lock(&Giant); 387 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 388 mtx_unlock(&Giant); 389 } 390} 391 392/* 393 * Utility function to load a linear buffer. lastaddrp holds state 394 * between invocations (for multiple-buffer loads). segp contains 395 * the starting segment on entrace, and the ending segment on exit. 396 * first indicates if this is the first invocation of this function. 397 */ 398static int 399_bus_dmamap_load_buffer(bus_dma_tag_t dmat, 400 bus_dmamap_t map, 401 bus_dma_segment_t segs[], 402 void *buf, bus_size_t buflen, 403 struct thread *td, 404 int flags, 405 bus_addr_t *lastaddrp, 406 int *segp, 407 int first) 408{ 409 bus_size_t sgsize; 410 bus_addr_t curaddr, lastaddr, baddr, bmask; 411 vm_offset_t vaddr; 412 bus_addr_t paddr; 413 int needbounce = 0; 414 int seg; 415 pmap_t pmap; 416 417 if (map == NULL) 418 map = &nobounce_dmamap; 419 420 if (td != NULL) 421 pmap = vmspace_pmap(td->td_proc->p_vmspace); 422 else 423 pmap = NULL; 424 425 if (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)) { 426 vm_offset_t vendaddr; 427 428 /* 429 * Count the number of bounce pages 430 * needed in order to complete this transfer 431 */ 432 vaddr = trunc_page((vm_offset_t)buf); 433 vendaddr = (vm_offset_t)buf + buflen; 434 435 while (vaddr < vendaddr) { 436 paddr = pmap_kextract(vaddr); 437 if (run_filter(dmat, paddr) != 0) { 438 needbounce = 1; 439 map->pagesneeded++; 440 } 441 vaddr += PAGE_SIZE; 442 } 443 } 444 445 vaddr = (vm_offset_t)buf; 446 447 /* Reserve Necessary Bounce Pages */ 448 if (map->pagesneeded != 0) { 449 mtx_lock(&bounce_lock); 450 if (flags & BUS_DMA_NOWAIT) { 451 if (reserve_bounce_pages(dmat, map, 0) != 0) { 452 mtx_unlock(&bounce_lock); 453 return (ENOMEM); 454 } 455 } else { 456 if (reserve_bounce_pages(dmat, map, 1) != 0) { 457 /* Queue us for resources */ 458 map->dmat = dmat; 459 map->buf = buf; 460 map->buflen = buflen; 461 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 462 map, links); 463 mtx_unlock(&bounce_lock); 464 return (EINPROGRESS); 465 } 466 } 467 mtx_unlock(&bounce_lock); 468 } 469 470 lastaddr = *lastaddrp; 471 bmask = ~(dmat->boundary - 1); 472 473 for (seg = *segp; buflen > 0 ; ) { 474 /* 475 * Get the physical address for this segment. 476 */ 477 if (pmap) 478 curaddr = pmap_extract(pmap, vaddr); 479 else 480 curaddr = pmap_kextract(vaddr); 481 482 /* 483 * Compute the segment size, and adjust counts. 484 */ 485 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK); 486 if (buflen < sgsize) 487 sgsize = buflen; 488 489 /* 490 * Make sure we don't cross any boundaries. 491 */ 492 if (dmat->boundary > 0) { 493 baddr = (curaddr + dmat->boundary) & bmask; 494 if (sgsize > (baddr - curaddr)) 495 sgsize = (baddr - curaddr); 496 } 497 498 if (map->pagesneeded != 0 && run_filter(dmat, curaddr)) 499 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 500 501 /* 502 * Insert chunk into a segment, coalescing with 503 * previous segment if possible. 504 */ 505 if (first) { 506 segs[seg].ds_addr = curaddr; 507 segs[seg].ds_len = sgsize; 508 first = 0; 509 } else { 510 if (needbounce == 0 && curaddr == lastaddr && 511 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 512 (dmat->boundary == 0 || 513 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 514 segs[seg].ds_len += sgsize; 515 else { 516 if (++seg >= dmat->nsegments) 517 break; 518 segs[seg].ds_addr = curaddr; 519 segs[seg].ds_len = sgsize; 520 } 521 } 522 523 lastaddr = curaddr + sgsize; 524 vaddr += sgsize; 525 buflen -= sgsize; 526 } 527 528 *segp = seg; 529 *lastaddrp = lastaddr; 530 531 /* 532 * Did we fit? 533 */ 534 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 535} 536 537#define BUS_DMAMAP_NSEGS ((64 * 1024) / PAGE_SIZE + 1) 538 539/* 540 * Map the buffer buf into bus space using the dmamap map. 541 */ 542int 543bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 544 bus_size_t buflen, bus_dmamap_callback_t *callback, 545 void *callback_arg, int flags) 546{ 547#ifdef __GNUC__ 548 bus_dma_segment_t dm_segments[dmat->nsegments]; 549#else 550 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 551#endif 552 bus_addr_t lastaddr = 0; 553 int error, nsegs = 0; 554 555 if (map != NULL) { 556 flags |= BUS_DMA_WAITOK; 557 map->callback = callback; 558 map->callback_arg = callback_arg; 559 } 560 561 error = _bus_dmamap_load_buffer(dmat, map, dm_segments, buf, buflen, 562 NULL, flags, &lastaddr, &nsegs, 1); 563 564 if (error == EINPROGRESS) 565 return (error); 566 567 if (error) 568 (*callback)(callback_arg, dm_segments, 0, error); 569 else 570 (*callback)(callback_arg, dm_segments, nsegs + 1, 0); 571 572 return (0); 573} 574 575 576/* 577 * Like _bus_dmamap_load(), but for mbufs. 578 */ 579int 580bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 581 struct mbuf *m0, 582 bus_dmamap_callback2_t *callback, void *callback_arg, 583 int flags) 584{ 585#ifdef __GNUC__ 586 bus_dma_segment_t dm_segments[dmat->nsegments]; 587#else 588 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 589#endif 590 int nsegs, error; 591 592 KASSERT(m0->m_flags & M_PKTHDR, 593 ("bus_dmamap_load_mbuf: no packet header")); 594 595 flags |= BUS_DMA_NOWAIT; 596 nsegs = 0; 597 error = 0; 598 if (m0->m_pkthdr.len <= dmat->maxsize) { 599 int first = 1; 600 bus_addr_t lastaddr = 0; 601 struct mbuf *m; 602 603 for (m = m0; m != NULL && error == 0; m = m->m_next) { 604 if (m->m_len > 0) { 605 error = _bus_dmamap_load_buffer(dmat, map, 606 dm_segments, 607 m->m_data, m->m_len, 608 NULL, flags, &lastaddr, 609 &nsegs, first); 610 first = 0; 611 } 612 } 613 } else { 614 error = EINVAL; 615 } 616 617 if (error) { 618 /* force "no valid mappings" in callback */ 619 (*callback)(callback_arg, dm_segments, 0, 0, error); 620 } else { 621 (*callback)(callback_arg, dm_segments, 622 nsegs+1, m0->m_pkthdr.len, error); 623 } 624 return (error); 625} 626 627/* 628 * Like _bus_dmamap_load(), but for uios. 629 */ 630int 631bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 632 struct uio *uio, 633 bus_dmamap_callback2_t *callback, void *callback_arg, 634 int flags) 635{ 636 bus_addr_t lastaddr; 637#ifdef __GNUC__ 638 bus_dma_segment_t dm_segments[dmat->nsegments]; 639#else 640 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 641#endif 642 int nsegs, error, first, i; 643 bus_size_t resid; 644 struct iovec *iov; 645 struct thread *td = NULL; 646 647 flags |= BUS_DMA_NOWAIT; 648 resid = uio->uio_resid; 649 iov = uio->uio_iov; 650 651 if (uio->uio_segflg == UIO_USERSPACE) { 652 td = uio->uio_td; 653 KASSERT(td != NULL, 654 ("bus_dmamap_load_uio: USERSPACE but no proc")); 655 } 656 657 nsegs = 0; 658 error = 0; 659 first = 1; 660 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 661 /* 662 * Now at the first iovec to load. Load each iovec 663 * until we have exhausted the residual count. 664 */ 665 bus_size_t minlen = 666 resid < iov[i].iov_len ? resid : iov[i].iov_len; 667 caddr_t addr = (caddr_t) iov[i].iov_base; 668 669 if (minlen > 0) { 670 error = _bus_dmamap_load_buffer(dmat, map, 671 dm_segments, 672 addr, minlen, 673 td, flags, &lastaddr, &nsegs, first); 674 first = 0; 675 676 resid -= minlen; 677 } 678 } 679 680 if (error) { 681 /* force "no valid mappings" in callback */ 682 (*callback)(callback_arg, dm_segments, 0, 0, error); 683 } else { 684 (*callback)(callback_arg, dm_segments, 685 nsegs+1, uio->uio_resid, error); 686 } 687 return (error); 688} 689 690/* 691 * Release the mapping held by map. 692 */ 693void 694_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 695{ 696 struct bounce_page *bpage; 697 698 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 699 STAILQ_REMOVE_HEAD(&map->bpages, links); 700 free_bounce_page(dmat, bpage); 701 } 702} 703 704void 705_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 706{ 707 struct bounce_page *bpage; 708 709 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 710 /* 711 * Handle data bouncing. We might also 712 * want to add support for invalidating 713 * the caches on broken hardware 714 */ 715 if (op & BUS_DMASYNC_PREWRITE) { 716 while (bpage != NULL) { 717 bcopy((void *)bpage->datavaddr, 718 (void *)bpage->vaddr, 719 bpage->datacount); 720 bpage = STAILQ_NEXT(bpage, links); 721 } 722 } 723 724 if (op & BUS_DMASYNC_POSTREAD) { 725 while (bpage != NULL) { 726 bcopy((void *)bpage->vaddr, 727 (void *)bpage->datavaddr, 728 bpage->datacount); 729 bpage = STAILQ_NEXT(bpage, links); 730 } 731 } 732 } 733} 734 735static void 736init_bounce_pages(void *dummy __unused) 737{ 738 739 free_bpages = 0; 740 reserved_bpages = 0; 741 active_bpages = 0; 742 total_bpages = 0; 743 STAILQ_INIT(&bounce_page_list); 744 STAILQ_INIT(&bounce_map_waitinglist); 745 STAILQ_INIT(&bounce_map_callbacklist); 746 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 747} 748SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 749 750static int 751alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 752{ 753 int count; 754 755 count = 0; 756 while (numpages > 0) { 757 struct bounce_page *bpage; 758 759 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 760 M_NOWAIT | M_ZERO); 761 762 if (bpage == NULL) 763 break; 764 mtx_lock(&Giant); 765 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 766 M_NOWAIT, 0ul, 767 dmat->lowaddr, 768 PAGE_SIZE, 769 0); 770 mtx_unlock(&Giant); 771 if (bpage->vaddr == 0) { 772 free(bpage, M_DEVBUF); 773 break; 774 } 775 bpage->busaddr = pmap_kextract(bpage->vaddr); 776 mtx_lock(&bounce_lock); 777 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links); 778 total_bpages++; 779 free_bpages++; 780 mtx_unlock(&bounce_lock); 781 count++; 782 numpages--; 783 } 784 return (count); 785} 786 787static int 788reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 789{ 790 int pages; 791 792 mtx_assert(&bounce_lock, MA_OWNED); 793 pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved); 794 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 795 return (map->pagesneeded - (map->pagesreserved + pages)); 796 free_bpages -= pages; 797 reserved_bpages += pages; 798 map->pagesreserved += pages; 799 pages = map->pagesneeded - map->pagesreserved; 800 801 return (pages); 802} 803 804static bus_addr_t 805add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 806 bus_size_t size) 807{ 808 struct bounce_page *bpage; 809 810 KASSERT(map != NULL && map != &nobounce_dmamap, 811 ("add_bounce_page: bad map %p", map)); 812 813 if (map->pagesneeded == 0) 814 panic("add_bounce_page: map doesn't need any pages"); 815 map->pagesneeded--; 816 817 if (map->pagesreserved == 0) 818 panic("add_bounce_page: map doesn't need any pages"); 819 map->pagesreserved--; 820 821 mtx_lock(&bounce_lock); 822 bpage = STAILQ_FIRST(&bounce_page_list); 823 if (bpage == NULL) 824 panic("add_bounce_page: free page list is empty"); 825 826 STAILQ_REMOVE_HEAD(&bounce_page_list, links); 827 reserved_bpages--; 828 active_bpages++; 829 mtx_unlock(&bounce_lock); 830 831 bpage->datavaddr = vaddr; 832 bpage->datacount = size; 833 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 834 return (bpage->busaddr); 835} 836 837static void 838free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 839{ 840 struct bus_dmamap *map; 841 842 bpage->datavaddr = 0; 843 bpage->datacount = 0; 844 845 mtx_lock(&bounce_lock); 846 STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links); 847 free_bpages++; 848 active_bpages--; 849 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 850 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 851 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 852 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 853 map, links); 854 busdma_swi_pending = 1; 855 swi_sched(vm_ih, 0); 856 } 857 } 858 mtx_unlock(&bounce_lock); 859} 860 861void 862busdma_swi(void) 863{ 864 struct bus_dmamap *map; 865 866 mtx_lock(&bounce_lock); 867 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 868 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 869 mtx_unlock(&bounce_lock); 870 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 871 map->callback, map->callback_arg, /*flags*/0); 872 mtx_lock(&bounce_lock); 873 } 874 mtx_unlock(&bounce_lock); 875} 876