busdma_machdep.c revision 115683
1/* 2 * Copyright (c) 1997, 1998 Justin T. Gibbs. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions, and the following disclaimer, 10 * without modification, immediately at the beginning of the file. 11 * 2. The name of the author may not be used to endorse or promote products 12 * derived from this software without specific prior written permission. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 18 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: head/sys/i386/i386/busdma_machdep.c 115683 2003-06-02 06:43:15Z obrien $"); 30 31#include <sys/param.h> 32#include <sys/systm.h> 33#include <sys/malloc.h> 34#include <sys/bus.h> 35#include <sys/interrupt.h> 36#include <sys/kernel.h> 37#include <sys/lock.h> 38#include <sys/proc.h> 39#include <sys/mutex.h> 40#include <sys/mbuf.h> 41#include <sys/uio.h> 42 43#include <vm/vm.h> 44#include <vm/vm_page.h> 45#include <vm/vm_map.h> 46 47#include <machine/atomic.h> 48#include <machine/bus.h> 49#include <machine/md_var.h> 50 51#define MAX_BPAGES 512 52 53struct bus_dma_tag { 54 bus_dma_tag_t parent; 55 bus_size_t alignment; 56 bus_size_t boundary; 57 bus_addr_t lowaddr; 58 bus_addr_t highaddr; 59 bus_dma_filter_t *filter; 60 void *filterarg; 61 bus_size_t maxsize; 62 u_int nsegments; 63 bus_size_t maxsegsz; 64 int flags; 65 int ref_count; 66 int map_count; 67}; 68 69struct bounce_page { 70 vm_offset_t vaddr; /* kva of bounce buffer */ 71 bus_addr_t busaddr; /* Physical address */ 72 vm_offset_t datavaddr; /* kva of client data */ 73 bus_size_t datacount; /* client data count */ 74 STAILQ_ENTRY(bounce_page) links; 75}; 76 77int busdma_swi_pending; 78 79static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 80static int free_bpages; 81static int reserved_bpages; 82static int active_bpages; 83static int total_bpages; 84static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR; 85 86struct bus_dmamap { 87 struct bp_list bpages; 88 int pagesneeded; 89 int pagesreserved; 90 bus_dma_tag_t dmat; 91 void *buf; /* unmapped buffer pointer */ 92 bus_size_t buflen; /* unmapped buffer length */ 93 bus_dmamap_callback_t *callback; 94 void *callback_arg; 95 STAILQ_ENTRY(bus_dmamap) links; 96}; 97 98static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 99static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 100static struct bus_dmamap nobounce_dmamap; 101 102static void init_bounce_pages(void *dummy); 103static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 104static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, 105 int commit); 106static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 107 vm_offset_t vaddr, bus_size_t size); 108static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 109static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 110 111/* To protect all the the bounce pages related lists and data. */ 112static struct mtx bounce_lock; 113 114/* 115 * Return true if a match is made. 116 * 117 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 118 * 119 * If paddr is within the bounds of the dma tag then call the filter callback 120 * to check for a match, if there is no filter callback then assume a match. 121 */ 122static __inline int 123run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 124{ 125 int retval; 126 127 retval = 0; 128 do { 129 if (paddr > dmat->lowaddr 130 && paddr <= dmat->highaddr 131 && (dmat->filter == NULL 132 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 133 retval = 1; 134 135 dmat = dmat->parent; 136 } while (retval == 0 && dmat != NULL); 137 return (retval); 138} 139 140#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 141/* 142 * Allocate a device specific dma_tag. 143 */ 144int 145bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 146 bus_size_t boundary, bus_addr_t lowaddr, 147 bus_addr_t highaddr, bus_dma_filter_t *filter, 148 void *filterarg, bus_size_t maxsize, int nsegments, 149 bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat) 150{ 151 bus_dma_tag_t newtag; 152 int error = 0; 153 154 /* Return a NULL tag on failure */ 155 *dmat = NULL; 156 157 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT); 158 if (newtag == NULL) 159 return (ENOMEM); 160 161 newtag->parent = parent; 162 newtag->alignment = alignment; 163 newtag->boundary = boundary; 164 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 165 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + 166 (PAGE_SIZE - 1); 167 newtag->filter = filter; 168 newtag->filterarg = filterarg; 169 newtag->maxsize = maxsize; 170 newtag->nsegments = nsegments; 171 newtag->maxsegsz = maxsegsz; 172 newtag->flags = flags; 173 newtag->ref_count = 1; /* Count ourself */ 174 newtag->map_count = 0; 175 176 /* Take into account any restrictions imposed by our parent tag */ 177 if (parent != NULL) { 178 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 179 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 180 /* 181 * XXX Not really correct??? Probably need to honor boundary 182 * all the way up the inheritence chain. 183 */ 184 newtag->boundary = MAX(parent->boundary, newtag->boundary); 185 if (newtag->filter == NULL) { 186 /* 187 * Short circuit looking at our parent directly 188 * since we have encapsulated all of its information 189 */ 190 newtag->filter = parent->filter; 191 newtag->filterarg = parent->filterarg; 192 newtag->parent = parent->parent; 193 } 194 if (newtag->parent != NULL) 195 atomic_add_int(&parent->ref_count, 1); 196 } 197 198 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) && 199 (flags & BUS_DMA_ALLOCNOW) != 0) { 200 /* Must bounce */ 201 202 if (lowaddr > bounce_lowaddr) { 203 /* 204 * Go through the pool and kill any pages 205 * that don't reside below lowaddr. 206 */ 207 panic("bus_dma_tag_create: page reallocation " 208 "not implemented"); 209 } 210 if (ptoa(total_bpages) < maxsize) { 211 int pages; 212 213 pages = atop(maxsize) - total_bpages; 214 215 /* Add pages to our bounce pool */ 216 if (alloc_bounce_pages(newtag, pages) < pages) 217 error = ENOMEM; 218 } 219 /* Performed initial allocation */ 220 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 221 } 222 223 if (error != 0) { 224 free(newtag, M_DEVBUF); 225 } else { 226 *dmat = newtag; 227 } 228 return (error); 229} 230 231int 232bus_dma_tag_destroy(bus_dma_tag_t dmat) 233{ 234 if (dmat != NULL) { 235 236 if (dmat->map_count != 0) 237 return (EBUSY); 238 239 while (dmat != NULL) { 240 bus_dma_tag_t parent; 241 242 parent = dmat->parent; 243 atomic_subtract_int(&dmat->ref_count, 1); 244 if (dmat->ref_count == 0) { 245 free(dmat, M_DEVBUF); 246 /* 247 * Last reference count, so 248 * release our reference 249 * count on our parent. 250 */ 251 dmat = parent; 252 } else 253 dmat = NULL; 254 } 255 } 256 return (0); 257} 258 259/* 260 * Allocate a handle for mapping from kva/uva/physical 261 * address space into bus device space. 262 */ 263int 264bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 265{ 266 int error; 267 268 error = 0; 269 270 if (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)) { 271 /* Must bounce */ 272 int maxpages; 273 274 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 275 M_NOWAIT | M_ZERO); 276 if (*mapp == NULL) 277 return (ENOMEM); 278 279 /* Initialize the new map */ 280 STAILQ_INIT(&((*mapp)->bpages)); 281 282 /* 283 * Attempt to add pages to our pool on a per-instance 284 * basis up to a sane limit. 285 */ 286 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr)); 287 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 288 || (dmat->map_count > 0 289 && total_bpages < maxpages)) { 290 int pages; 291 292 if (dmat->lowaddr > bounce_lowaddr) { 293 /* 294 * Go through the pool and kill any pages 295 * that don't reside below lowaddr. 296 */ 297 panic("bus_dmamap_create: page reallocation " 298 "not implemented"); 299 } 300 pages = MAX(atop(dmat->maxsize), 1); 301 pages = MIN(maxpages - total_bpages, pages); 302 if (alloc_bounce_pages(dmat, pages) < pages) 303 error = ENOMEM; 304 305 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 306 if (error == 0) 307 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 308 } else { 309 error = 0; 310 } 311 } 312 } else { 313 *mapp = NULL; 314 } 315 if (error == 0) 316 dmat->map_count++; 317 return (error); 318} 319 320/* 321 * Destroy a handle for mapping from kva/uva/physical 322 * address space into bus device space. 323 */ 324int 325bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 326{ 327 if (map != NULL) { 328 if (STAILQ_FIRST(&map->bpages) != NULL) 329 return (EBUSY); 330 free(map, M_DEVBUF); 331 } 332 dmat->map_count--; 333 return (0); 334} 335 336 337/* 338 * Allocate a piece of memory that can be efficiently mapped into 339 * bus device space based on the constraints lited in the dma tag. 340 * A dmamap to for use with dmamap_load is also allocated. 341 */ 342int 343bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 344 bus_dmamap_t *mapp) 345{ 346 /* If we succeed, no mapping/bouncing will be required */ 347 *mapp = NULL; 348 349 if ((dmat->maxsize <= PAGE_SIZE) && 350 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 351 *vaddr = malloc(dmat->maxsize, M_DEVBUF, 352 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK); 353 } else { 354 /* 355 * XXX Use Contigmalloc until it is merged into this facility 356 * and handles multi-seg allocations. Nobody is doing 357 * multi-seg allocations yet though. 358 */ 359 mtx_lock(&Giant); 360 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, 361 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK, 362 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 363 dmat->boundary); 364 mtx_unlock(&Giant); 365 } 366 if (*vaddr == NULL) 367 return (ENOMEM); 368 return (0); 369} 370 371/* 372 * Free a piece of memory and it's allociated dmamap, that was allocated 373 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 374 */ 375void 376bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 377{ 378 /* 379 * dmamem does not need to be bounced, so the map should be 380 * NULL 381 */ 382 if (map != NULL) 383 panic("bus_dmamem_free: Invalid map freed\n"); 384 if ((dmat->maxsize <= PAGE_SIZE) 385 && dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 386 free(vaddr, M_DEVBUF); 387 else { 388 mtx_lock(&Giant); 389 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 390 mtx_unlock(&Giant); 391 } 392} 393 394/* 395 * Utility function to load a linear buffer. lastaddrp holds state 396 * between invocations (for multiple-buffer loads). segp contains 397 * the starting segment on entrace, and the ending segment on exit. 398 * first indicates if this is the first invocation of this function. 399 */ 400static int 401_bus_dmamap_load_buffer(bus_dma_tag_t dmat, 402 bus_dmamap_t map, 403 bus_dma_segment_t segs[], 404 void *buf, bus_size_t buflen, 405 struct thread *td, 406 int flags, 407 bus_addr_t *lastaddrp, 408 int *segp, 409 int first) 410{ 411 bus_size_t sgsize; 412 bus_addr_t curaddr, lastaddr, baddr, bmask; 413 vm_offset_t vaddr; 414 bus_addr_t paddr; 415 int needbounce = 0; 416 int seg; 417 pmap_t pmap; 418 419 if (map == NULL) 420 map = &nobounce_dmamap; 421 422 if (td != NULL) 423 pmap = vmspace_pmap(td->td_proc->p_vmspace); 424 else 425 pmap = NULL; 426 427 if (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)) { 428 vm_offset_t vendaddr; 429 430 /* 431 * Count the number of bounce pages 432 * needed in order to complete this transfer 433 */ 434 vaddr = trunc_page((vm_offset_t)buf); 435 vendaddr = (vm_offset_t)buf + buflen; 436 437 while (vaddr < vendaddr) { 438 paddr = pmap_kextract(vaddr); 439 if (run_filter(dmat, paddr) != 0) { 440 needbounce = 1; 441 map->pagesneeded++; 442 } 443 vaddr += PAGE_SIZE; 444 } 445 } 446 447 vaddr = (vm_offset_t)buf; 448 449 /* Reserve Necessary Bounce Pages */ 450 if (map->pagesneeded != 0) { 451 mtx_lock(&bounce_lock); 452 if (flags & BUS_DMA_NOWAIT) { 453 if (reserve_bounce_pages(dmat, map, 0) != 0) { 454 mtx_unlock(&bounce_lock); 455 return (ENOMEM); 456 } 457 } else { 458 if (reserve_bounce_pages(dmat, map, 1) != 0) { 459 /* Queue us for resources */ 460 map->dmat = dmat; 461 map->buf = buf; 462 map->buflen = buflen; 463 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 464 map, links); 465 mtx_unlock(&bounce_lock); 466 return (EINPROGRESS); 467 } 468 } 469 mtx_unlock(&bounce_lock); 470 } 471 472 lastaddr = *lastaddrp; 473 bmask = ~(dmat->boundary - 1); 474 475 for (seg = *segp; buflen > 0 ; ) { 476 /* 477 * Get the physical address for this segment. 478 */ 479 if (pmap) 480 curaddr = pmap_extract(pmap, vaddr); 481 else 482 curaddr = pmap_kextract(vaddr); 483 484 /* 485 * Compute the segment size, and adjust counts. 486 */ 487 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK); 488 if (buflen < sgsize) 489 sgsize = buflen; 490 491 /* 492 * Make sure we don't cross any boundaries. 493 */ 494 if (dmat->boundary > 0) { 495 baddr = (curaddr + dmat->boundary) & bmask; 496 if (sgsize > (baddr - curaddr)) 497 sgsize = (baddr - curaddr); 498 } 499 500 if (map->pagesneeded != 0 && run_filter(dmat, curaddr)) 501 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 502 503 /* 504 * Insert chunk into a segment, coalescing with 505 * previous segment if possible. 506 */ 507 if (first) { 508 segs[seg].ds_addr = curaddr; 509 segs[seg].ds_len = sgsize; 510 first = 0; 511 } else { 512 if (needbounce == 0 && curaddr == lastaddr && 513 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 514 (dmat->boundary == 0 || 515 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 516 segs[seg].ds_len += sgsize; 517 else { 518 if (++seg >= dmat->nsegments) 519 break; 520 segs[seg].ds_addr = curaddr; 521 segs[seg].ds_len = sgsize; 522 } 523 } 524 525 lastaddr = curaddr + sgsize; 526 vaddr += sgsize; 527 buflen -= sgsize; 528 } 529 530 *segp = seg; 531 *lastaddrp = lastaddr; 532 533 /* 534 * Did we fit? 535 */ 536 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 537} 538 539#define BUS_DMAMAP_NSEGS ((64 * 1024) / PAGE_SIZE + 1) 540 541/* 542 * Map the buffer buf into bus space using the dmamap map. 543 */ 544int 545bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 546 bus_size_t buflen, bus_dmamap_callback_t *callback, 547 void *callback_arg, int flags) 548{ 549#ifdef __GNUC__ 550 bus_dma_segment_t dm_segments[dmat->nsegments]; 551#else 552 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 553#endif 554 bus_addr_t lastaddr = 0; 555 int error, nsegs = 0; 556 557 if (map != NULL) { 558 flags |= BUS_DMA_WAITOK; 559 map->callback = callback; 560 map->callback_arg = callback_arg; 561 } 562 563 error = _bus_dmamap_load_buffer(dmat, map, dm_segments, buf, buflen, 564 NULL, flags, &lastaddr, &nsegs, 1); 565 566 if (error == EINPROGRESS) 567 return (error); 568 569 if (error) 570 (*callback)(callback_arg, dm_segments, 0, error); 571 else 572 (*callback)(callback_arg, dm_segments, nsegs + 1, 0); 573 574 return (0); 575} 576 577 578/* 579 * Like _bus_dmamap_load(), but for mbufs. 580 */ 581int 582bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 583 struct mbuf *m0, 584 bus_dmamap_callback2_t *callback, void *callback_arg, 585 int flags) 586{ 587#ifdef __GNUC__ 588 bus_dma_segment_t dm_segments[dmat->nsegments]; 589#else 590 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 591#endif 592 int nsegs, error; 593 594 KASSERT(m0->m_flags & M_PKTHDR, 595 ("bus_dmamap_load_mbuf: no packet header")); 596 597 flags |= BUS_DMA_NOWAIT; 598 nsegs = 0; 599 error = 0; 600 if (m0->m_pkthdr.len <= dmat->maxsize) { 601 int first = 1; 602 bus_addr_t lastaddr = 0; 603 struct mbuf *m; 604 605 for (m = m0; m != NULL && error == 0; m = m->m_next) { 606 if (m->m_len > 0) { 607 error = _bus_dmamap_load_buffer(dmat, map, 608 dm_segments, 609 m->m_data, m->m_len, 610 NULL, flags, &lastaddr, 611 &nsegs, first); 612 first = 0; 613 } 614 } 615 } else { 616 error = EINVAL; 617 } 618 619 if (error) { 620 /* force "no valid mappings" in callback */ 621 (*callback)(callback_arg, dm_segments, 0, 0, error); 622 } else { 623 (*callback)(callback_arg, dm_segments, 624 nsegs+1, m0->m_pkthdr.len, error); 625 } 626 return (error); 627} 628 629/* 630 * Like _bus_dmamap_load(), but for uios. 631 */ 632int 633bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 634 struct uio *uio, 635 bus_dmamap_callback2_t *callback, void *callback_arg, 636 int flags) 637{ 638 bus_addr_t lastaddr; 639#ifdef __GNUC__ 640 bus_dma_segment_t dm_segments[dmat->nsegments]; 641#else 642 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 643#endif 644 int nsegs, error, first, i; 645 bus_size_t resid; 646 struct iovec *iov; 647 struct thread *td = NULL; 648 649 flags |= BUS_DMA_NOWAIT; 650 resid = uio->uio_resid; 651 iov = uio->uio_iov; 652 653 if (uio->uio_segflg == UIO_USERSPACE) { 654 td = uio->uio_td; 655 KASSERT(td != NULL, 656 ("bus_dmamap_load_uio: USERSPACE but no proc")); 657 } 658 659 nsegs = 0; 660 error = 0; 661 first = 1; 662 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 663 /* 664 * Now at the first iovec to load. Load each iovec 665 * until we have exhausted the residual count. 666 */ 667 bus_size_t minlen = 668 resid < iov[i].iov_len ? resid : iov[i].iov_len; 669 caddr_t addr = (caddr_t) iov[i].iov_base; 670 671 if (minlen > 0) { 672 error = _bus_dmamap_load_buffer(dmat, map, 673 dm_segments, 674 addr, minlen, 675 td, flags, &lastaddr, &nsegs, first); 676 first = 0; 677 678 resid -= minlen; 679 } 680 } 681 682 if (error) { 683 /* force "no valid mappings" in callback */ 684 (*callback)(callback_arg, dm_segments, 0, 0, error); 685 } else { 686 (*callback)(callback_arg, dm_segments, 687 nsegs+1, uio->uio_resid, error); 688 } 689 return (error); 690} 691 692/* 693 * Release the mapping held by map. 694 */ 695void 696_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 697{ 698 struct bounce_page *bpage; 699 700 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 701 STAILQ_REMOVE_HEAD(&map->bpages, links); 702 free_bounce_page(dmat, bpage); 703 } 704} 705 706void 707_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 708{ 709 struct bounce_page *bpage; 710 711 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 712 /* 713 * Handle data bouncing. We might also 714 * want to add support for invalidating 715 * the caches on broken hardware 716 */ 717 if (op & BUS_DMASYNC_PREWRITE) { 718 while (bpage != NULL) { 719 bcopy((void *)bpage->datavaddr, 720 (void *)bpage->vaddr, 721 bpage->datacount); 722 bpage = STAILQ_NEXT(bpage, links); 723 } 724 } 725 726 if (op & BUS_DMASYNC_POSTREAD) { 727 while (bpage != NULL) { 728 bcopy((void *)bpage->vaddr, 729 (void *)bpage->datavaddr, 730 bpage->datacount); 731 bpage = STAILQ_NEXT(bpage, links); 732 } 733 } 734 } 735} 736 737static void 738init_bounce_pages(void *dummy __unused) 739{ 740 741 free_bpages = 0; 742 reserved_bpages = 0; 743 active_bpages = 0; 744 total_bpages = 0; 745 STAILQ_INIT(&bounce_page_list); 746 STAILQ_INIT(&bounce_map_waitinglist); 747 STAILQ_INIT(&bounce_map_callbacklist); 748 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 749} 750SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 751 752static int 753alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 754{ 755 int count; 756 757 count = 0; 758 while (numpages > 0) { 759 struct bounce_page *bpage; 760 761 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 762 M_NOWAIT | M_ZERO); 763 764 if (bpage == NULL) 765 break; 766 mtx_lock(&Giant); 767 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 768 M_NOWAIT, 0ul, 769 dmat->lowaddr, 770 PAGE_SIZE, 771 0); 772 mtx_unlock(&Giant); 773 if (bpage->vaddr == 0) { 774 free(bpage, M_DEVBUF); 775 break; 776 } 777 bpage->busaddr = pmap_kextract(bpage->vaddr); 778 mtx_lock(&bounce_lock); 779 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links); 780 total_bpages++; 781 free_bpages++; 782 mtx_unlock(&bounce_lock); 783 count++; 784 numpages--; 785 } 786 return (count); 787} 788 789static int 790reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 791{ 792 int pages; 793 794 mtx_assert(&bounce_lock, MA_OWNED); 795 pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved); 796 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 797 return (map->pagesneeded - (map->pagesreserved + pages)); 798 free_bpages -= pages; 799 reserved_bpages += pages; 800 map->pagesreserved += pages; 801 pages = map->pagesneeded - map->pagesreserved; 802 803 return (pages); 804} 805 806static bus_addr_t 807add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 808 bus_size_t size) 809{ 810 struct bounce_page *bpage; 811 812 KASSERT(map != NULL && map != &nobounce_dmamap, 813 ("add_bounce_page: bad map %p", map)); 814 815 if (map->pagesneeded == 0) 816 panic("add_bounce_page: map doesn't need any pages"); 817 map->pagesneeded--; 818 819 if (map->pagesreserved == 0) 820 panic("add_bounce_page: map doesn't need any pages"); 821 map->pagesreserved--; 822 823 mtx_lock(&bounce_lock); 824 bpage = STAILQ_FIRST(&bounce_page_list); 825 if (bpage == NULL) 826 panic("add_bounce_page: free page list is empty"); 827 828 STAILQ_REMOVE_HEAD(&bounce_page_list, links); 829 reserved_bpages--; 830 active_bpages++; 831 mtx_unlock(&bounce_lock); 832 833 bpage->datavaddr = vaddr; 834 bpage->datacount = size; 835 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 836 return (bpage->busaddr); 837} 838 839static void 840free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 841{ 842 struct bus_dmamap *map; 843 844 bpage->datavaddr = 0; 845 bpage->datacount = 0; 846 847 mtx_lock(&bounce_lock); 848 STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links); 849 free_bpages++; 850 active_bpages--; 851 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 852 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 853 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 854 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 855 map, links); 856 busdma_swi_pending = 1; 857 swi_sched(vm_ih, 0); 858 } 859 } 860 mtx_unlock(&bounce_lock); 861} 862 863void 864busdma_swi(void) 865{ 866 struct bus_dmamap *map; 867 868 mtx_lock(&bounce_lock); 869 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 870 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 871 mtx_unlock(&bounce_lock); 872 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 873 map->callback, map->callback_arg, /*flags*/0); 874 mtx_lock(&bounce_lock); 875 } 876 mtx_unlock(&bounce_lock); 877} 878