busdma_machdep.c revision 117126
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 117126 2003-07-01 15:52:06Z scottl $"); 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 bus_dma_lock_t *lockfunc; 68 void *lockfuncarg; 69}; 70 71struct bounce_page { 72 vm_offset_t vaddr; /* kva of bounce buffer */ 73 bus_addr_t busaddr; /* Physical address */ 74 vm_offset_t datavaddr; /* kva of client data */ 75 bus_size_t datacount; /* client data count */ 76 STAILQ_ENTRY(bounce_page) links; 77}; 78 79int busdma_swi_pending; 80 81static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 82static int free_bpages; 83static int reserved_bpages; 84static int active_bpages; 85static int total_bpages; 86static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR; 87 88struct bus_dmamap { 89 struct bp_list bpages; 90 int pagesneeded; 91 int pagesreserved; 92 bus_dma_tag_t dmat; 93 void *buf; /* unmapped buffer pointer */ 94 bus_size_t buflen; /* unmapped buffer length */ 95 bus_dmamap_callback_t *callback; 96 void *callback_arg; 97 STAILQ_ENTRY(bus_dmamap) links; 98}; 99 100static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 101static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 102static struct bus_dmamap nobounce_dmamap; 103 104static void init_bounce_pages(void *dummy); 105static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 106static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, 107 int commit); 108static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 109 vm_offset_t vaddr, bus_size_t size); 110static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 111static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 112 113/* To protect all the the bounce pages related lists and data. */ 114static struct mtx bounce_lock; 115 116/* 117 * Return true if a match is made. 118 * 119 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 120 * 121 * If paddr is within the bounds of the dma tag then call the filter callback 122 * to check for a match, if there is no filter callback then assume a match. 123 */ 124static __inline int 125run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 126{ 127 int retval; 128 129 retval = 0; 130 do { 131 if (paddr > dmat->lowaddr 132 && paddr <= dmat->highaddr 133 && (dmat->filter == NULL 134 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 135 retval = 1; 136 137 dmat = dmat->parent; 138 } while (retval == 0 && dmat != NULL); 139 return (retval); 140} 141 142/* 143 * Convenience function for manipulating driver locks from busdma (during 144 * busdma_swi, for example). Drivers that don't provide their own locks 145 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own 146 * non-mutex locking scheme don't have to use this at all. 147 */ 148void 149busdma_lock_mutex(void *arg, bus_dma_lock_op_t op) 150{ 151 struct mtx *dmtx; 152 153 dmtx = (struct mtx *)arg; 154 switch (op) { 155 case BUS_DMA_LOCK: 156 mtx_lock(dmtx); 157 break; 158 case BUS_DMA_UNLOCK: 159 mtx_unlock(dmtx); 160 break; 161 default: 162 panic("Unknown operation 0x%x for busdma_lock_mutex!", op); 163 } 164} 165 166/* 167 * dflt_lock should never get called. It gets put into the dma tag when 168 * lockfunc == NULL, which is only valid if the maps that are associated 169 * with the tag are meant to never be defered. 170 * XXX Should have a way to identify which driver is responsible here. 171 */ 172static void 173dflt_lock(void *arg, bus_dma_lock_op_t op) 174{ 175#ifdef INVARIANTS 176 panic("driver error: busdma dflt_lock called"); 177#else 178 printf("DRIVER_ERROR: busdma dflt_lock called\n"); 179#endif 180} 181 182#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 183/* 184 * Allocate a device specific dma_tag. 185 */ 186int 187bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 188 bus_size_t boundary, bus_addr_t lowaddr, 189 bus_addr_t highaddr, bus_dma_filter_t *filter, 190 void *filterarg, bus_size_t maxsize, int nsegments, 191 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc, 192 void *lockfuncarg, bus_dma_tag_t *dmat) 193{ 194 bus_dma_tag_t newtag; 195 int error = 0; 196 197 /* Return a NULL tag on failure */ 198 *dmat = NULL; 199 200 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT); 201 if (newtag == NULL) 202 return (ENOMEM); 203 204 newtag->parent = parent; 205 newtag->alignment = alignment; 206 newtag->boundary = boundary; 207 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 208 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + 209 (PAGE_SIZE - 1); 210 newtag->filter = filter; 211 newtag->filterarg = filterarg; 212 newtag->maxsize = maxsize; 213 newtag->nsegments = nsegments; 214 newtag->maxsegsz = maxsegsz; 215 newtag->flags = flags; 216 newtag->ref_count = 1; /* Count ourself */ 217 newtag->map_count = 0; 218 if (lockfunc != NULL) { 219 newtag->lockfunc = lockfunc; 220 newtag->lockfuncarg = lockfuncarg; 221 } else { 222 newtag->lockfunc = dflt_lock; 223 newtag->lockfuncarg = NULL; 224 } 225 226 /* Take into account any restrictions imposed by our parent tag */ 227 if (parent != NULL) { 228 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 229 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 230 /* 231 * XXX Not really correct??? Probably need to honor boundary 232 * all the way up the inheritence chain. 233 */ 234 newtag->boundary = MAX(parent->boundary, newtag->boundary); 235 if (newtag->filter == NULL) { 236 /* 237 * Short circuit looking at our parent directly 238 * since we have encapsulated all of its information 239 */ 240 newtag->filter = parent->filter; 241 newtag->filterarg = parent->filterarg; 242 newtag->parent = parent->parent; 243 } 244 if (newtag->parent != NULL) 245 atomic_add_int(&parent->ref_count, 1); 246 } 247 248 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) && 249 (flags & BUS_DMA_ALLOCNOW) != 0) { 250 /* Must bounce */ 251 252 if (lowaddr > bounce_lowaddr) { 253 /* 254 * Go through the pool and kill any pages 255 * that don't reside below lowaddr. 256 */ 257 panic("bus_dma_tag_create: page reallocation " 258 "not implemented"); 259 } 260 if (ptoa(total_bpages) < maxsize) { 261 int pages; 262 263 pages = atop(maxsize) - total_bpages; 264 265 /* Add pages to our bounce pool */ 266 if (alloc_bounce_pages(newtag, pages) < pages) 267 error = ENOMEM; 268 } 269 /* Performed initial allocation */ 270 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 271 } 272 273 if (error != 0) { 274 free(newtag, M_DEVBUF); 275 } else { 276 *dmat = newtag; 277 } 278 return (error); 279} 280 281int 282bus_dma_tag_destroy(bus_dma_tag_t dmat) 283{ 284 if (dmat != NULL) { 285 286 if (dmat->map_count != 0) 287 return (EBUSY); 288 289 while (dmat != NULL) { 290 bus_dma_tag_t parent; 291 292 parent = dmat->parent; 293 atomic_subtract_int(&dmat->ref_count, 1); 294 if (dmat->ref_count == 0) { 295 free(dmat, M_DEVBUF); 296 /* 297 * Last reference count, so 298 * release our reference 299 * count on our parent. 300 */ 301 dmat = parent; 302 } else 303 dmat = NULL; 304 } 305 } 306 return (0); 307} 308 309/* 310 * Allocate a handle for mapping from kva/uva/physical 311 * address space into bus device space. 312 */ 313int 314bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 315{ 316 int error; 317 318 error = 0; 319 320 if (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)) { 321 /* Must bounce */ 322 int maxpages; 323 324 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 325 M_NOWAIT | M_ZERO); 326 if (*mapp == NULL) 327 return (ENOMEM); 328 329 /* Initialize the new map */ 330 STAILQ_INIT(&((*mapp)->bpages)); 331 332 /* 333 * Attempt to add pages to our pool on a per-instance 334 * basis up to a sane limit. 335 */ 336 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr)); 337 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 338 || (dmat->map_count > 0 339 && total_bpages < maxpages)) { 340 int pages; 341 342 if (dmat->lowaddr > bounce_lowaddr) { 343 /* 344 * Go through the pool and kill any pages 345 * that don't reside below lowaddr. 346 */ 347 panic("bus_dmamap_create: page reallocation " 348 "not implemented"); 349 } 350 pages = MAX(atop(dmat->maxsize), 1); 351 pages = MIN(maxpages - total_bpages, pages); 352 if (alloc_bounce_pages(dmat, pages) < pages) 353 error = ENOMEM; 354 355 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 356 if (error == 0) 357 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 358 } else { 359 error = 0; 360 } 361 } 362 } else { 363 *mapp = NULL; 364 } 365 if (error == 0) 366 dmat->map_count++; 367 return (error); 368} 369 370/* 371 * Destroy a handle for mapping from kva/uva/physical 372 * address space into bus device space. 373 */ 374int 375bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 376{ 377 if (map != NULL) { 378 if (STAILQ_FIRST(&map->bpages) != NULL) 379 return (EBUSY); 380 free(map, M_DEVBUF); 381 } 382 dmat->map_count--; 383 return (0); 384} 385 386 387/* 388 * Allocate a piece of memory that can be efficiently mapped into 389 * bus device space based on the constraints lited in the dma tag. 390 * A dmamap to for use with dmamap_load is also allocated. 391 */ 392int 393bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 394 bus_dmamap_t *mapp) 395{ 396 /* If we succeed, no mapping/bouncing will be required */ 397 *mapp = NULL; 398 399 if ((dmat->maxsize <= PAGE_SIZE) && 400 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 401 *vaddr = malloc(dmat->maxsize, M_DEVBUF, 402 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK); 403 } else { 404 /* 405 * XXX Use Contigmalloc until it is merged into this facility 406 * and handles multi-seg allocations. Nobody is doing 407 * multi-seg allocations yet though. 408 */ 409 mtx_lock(&Giant); 410 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, 411 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK, 412 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 413 dmat->boundary); 414 mtx_unlock(&Giant); 415 } 416 if (*vaddr == NULL) 417 return (ENOMEM); 418 return (0); 419} 420 421/* 422 * Free a piece of memory and it's allociated dmamap, that was allocated 423 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 424 */ 425void 426bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 427{ 428 /* 429 * dmamem does not need to be bounced, so the map should be 430 * NULL 431 */ 432 if (map != NULL) 433 panic("bus_dmamem_free: Invalid map freed\n"); 434 if ((dmat->maxsize <= PAGE_SIZE) 435 && dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 436 free(vaddr, M_DEVBUF); 437 else { 438 mtx_lock(&Giant); 439 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 440 mtx_unlock(&Giant); 441 } 442} 443 444/* 445 * Utility function to load a linear buffer. lastaddrp holds state 446 * between invocations (for multiple-buffer loads). segp contains 447 * the starting segment on entrace, and the ending segment on exit. 448 * first indicates if this is the first invocation of this function. 449 */ 450static int 451_bus_dmamap_load_buffer(bus_dma_tag_t dmat, 452 bus_dmamap_t map, 453 bus_dma_segment_t segs[], 454 void *buf, bus_size_t buflen, 455 struct thread *td, 456 int flags, 457 bus_addr_t *lastaddrp, 458 int *segp, 459 int first) 460{ 461 bus_size_t sgsize; 462 bus_addr_t curaddr, lastaddr, baddr, bmask; 463 vm_offset_t vaddr; 464 bus_addr_t paddr; 465 int needbounce = 0; 466 int seg; 467 pmap_t pmap; 468 469 if (map == NULL) 470 map = &nobounce_dmamap; 471 472 if (td != NULL) 473 pmap = vmspace_pmap(td->td_proc->p_vmspace); 474 else 475 pmap = NULL; 476 477 if (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)) { 478 vm_offset_t vendaddr; 479 480 /* 481 * Count the number of bounce pages 482 * needed in order to complete this transfer 483 */ 484 vaddr = trunc_page((vm_offset_t)buf); 485 vendaddr = (vm_offset_t)buf + buflen; 486 487 while (vaddr < vendaddr) { 488 paddr = pmap_kextract(vaddr); 489 if (run_filter(dmat, paddr) != 0) { 490 needbounce = 1; 491 map->pagesneeded++; 492 } 493 vaddr += PAGE_SIZE; 494 } 495 } 496 497 vaddr = (vm_offset_t)buf; 498 499 /* Reserve Necessary Bounce Pages */ 500 if (map->pagesneeded != 0) { 501 mtx_lock(&bounce_lock); 502 if (flags & BUS_DMA_NOWAIT) { 503 if (reserve_bounce_pages(dmat, map, 0) != 0) { 504 mtx_unlock(&bounce_lock); 505 return (ENOMEM); 506 } 507 } else { 508 if (reserve_bounce_pages(dmat, map, 1) != 0) { 509 /* Queue us for resources */ 510 map->dmat = dmat; 511 map->buf = buf; 512 map->buflen = buflen; 513 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 514 map, links); 515 mtx_unlock(&bounce_lock); 516 return (EINPROGRESS); 517 } 518 } 519 mtx_unlock(&bounce_lock); 520 } 521 522 lastaddr = *lastaddrp; 523 bmask = ~(dmat->boundary - 1); 524 525 for (seg = *segp; buflen > 0 ; ) { 526 /* 527 * Get the physical address for this segment. 528 */ 529 if (pmap) 530 curaddr = pmap_extract(pmap, vaddr); 531 else 532 curaddr = pmap_kextract(vaddr); 533 534 /* 535 * Compute the segment size, and adjust counts. 536 */ 537 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK); 538 if (buflen < sgsize) 539 sgsize = buflen; 540 541 /* 542 * Make sure we don't cross any boundaries. 543 */ 544 if (dmat->boundary > 0) { 545 baddr = (curaddr + dmat->boundary) & bmask; 546 if (sgsize > (baddr - curaddr)) 547 sgsize = (baddr - curaddr); 548 } 549 550 if (map->pagesneeded != 0 && run_filter(dmat, curaddr)) 551 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 552 553 /* 554 * Insert chunk into a segment, coalescing with 555 * previous segment if possible. 556 */ 557 if (first) { 558 segs[seg].ds_addr = curaddr; 559 segs[seg].ds_len = sgsize; 560 first = 0; 561 } else { 562 if (needbounce == 0 && curaddr == lastaddr && 563 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 564 (dmat->boundary == 0 || 565 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 566 segs[seg].ds_len += sgsize; 567 else { 568 if (++seg >= dmat->nsegments) 569 break; 570 segs[seg].ds_addr = curaddr; 571 segs[seg].ds_len = sgsize; 572 } 573 } 574 575 lastaddr = curaddr + sgsize; 576 vaddr += sgsize; 577 buflen -= sgsize; 578 } 579 580 *segp = seg; 581 *lastaddrp = lastaddr; 582 583 /* 584 * Did we fit? 585 */ 586 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 587} 588 589#define BUS_DMAMAP_NSEGS ((64 * 1024) / PAGE_SIZE + 1) 590 591/* 592 * Map the buffer buf into bus space using the dmamap map. 593 */ 594int 595bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 596 bus_size_t buflen, bus_dmamap_callback_t *callback, 597 void *callback_arg, int flags) 598{ 599#ifdef __GNUC__ 600 bus_dma_segment_t dm_segments[dmat->nsegments]; 601#else 602 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 603#endif 604 bus_addr_t lastaddr = 0; 605 int error, nsegs = 0; 606 607 if (map != NULL) { 608 flags |= BUS_DMA_WAITOK; 609 map->callback = callback; 610 map->callback_arg = callback_arg; 611 } 612 613 error = _bus_dmamap_load_buffer(dmat, map, dm_segments, buf, buflen, 614 NULL, flags, &lastaddr, &nsegs, 1); 615 616 if (error == EINPROGRESS) 617 return (error); 618 619 if (error) 620 (*callback)(callback_arg, dm_segments, 0, error); 621 else 622 (*callback)(callback_arg, dm_segments, nsegs + 1, 0); 623 624 return (0); 625} 626 627 628/* 629 * Like _bus_dmamap_load(), but for mbufs. 630 */ 631int 632bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 633 struct mbuf *m0, 634 bus_dmamap_callback2_t *callback, void *callback_arg, 635 int flags) 636{ 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; 643 644 KASSERT(m0->m_flags & M_PKTHDR, 645 ("bus_dmamap_load_mbuf: no packet header")); 646 647 flags |= BUS_DMA_NOWAIT; 648 nsegs = 0; 649 error = 0; 650 if (m0->m_pkthdr.len <= dmat->maxsize) { 651 int first = 1; 652 bus_addr_t lastaddr = 0; 653 struct mbuf *m; 654 655 for (m = m0; m != NULL && error == 0; m = m->m_next) { 656 if (m->m_len > 0) { 657 error = _bus_dmamap_load_buffer(dmat, map, 658 dm_segments, 659 m->m_data, m->m_len, 660 NULL, flags, &lastaddr, 661 &nsegs, first); 662 first = 0; 663 } 664 } 665 } else { 666 error = EINVAL; 667 } 668 669 if (error) { 670 /* force "no valid mappings" in callback */ 671 (*callback)(callback_arg, dm_segments, 0, 0, error); 672 } else { 673 (*callback)(callback_arg, dm_segments, 674 nsegs+1, m0->m_pkthdr.len, error); 675 } 676 return (error); 677} 678 679/* 680 * Like _bus_dmamap_load(), but for uios. 681 */ 682int 683bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 684 struct uio *uio, 685 bus_dmamap_callback2_t *callback, void *callback_arg, 686 int flags) 687{ 688 bus_addr_t lastaddr; 689#ifdef __GNUC__ 690 bus_dma_segment_t dm_segments[dmat->nsegments]; 691#else 692 bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS]; 693#endif 694 int nsegs, error, first, i; 695 bus_size_t resid; 696 struct iovec *iov; 697 struct thread *td = NULL; 698 699 flags |= BUS_DMA_NOWAIT; 700 resid = uio->uio_resid; 701 iov = uio->uio_iov; 702 703 if (uio->uio_segflg == UIO_USERSPACE) { 704 td = uio->uio_td; 705 KASSERT(td != NULL, 706 ("bus_dmamap_load_uio: USERSPACE but no proc")); 707 } 708 709 nsegs = 0; 710 error = 0; 711 first = 1; 712 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 713 /* 714 * Now at the first iovec to load. Load each iovec 715 * until we have exhausted the residual count. 716 */ 717 bus_size_t minlen = 718 resid < iov[i].iov_len ? resid : iov[i].iov_len; 719 caddr_t addr = (caddr_t) iov[i].iov_base; 720 721 if (minlen > 0) { 722 error = _bus_dmamap_load_buffer(dmat, map, 723 dm_segments, 724 addr, minlen, 725 td, flags, &lastaddr, &nsegs, first); 726 first = 0; 727 728 resid -= minlen; 729 } 730 } 731 732 if (error) { 733 /* force "no valid mappings" in callback */ 734 (*callback)(callback_arg, dm_segments, 0, 0, error); 735 } else { 736 (*callback)(callback_arg, dm_segments, 737 nsegs+1, uio->uio_resid, error); 738 } 739 return (error); 740} 741 742/* 743 * Release the mapping held by map. 744 */ 745void 746_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 747{ 748 struct bounce_page *bpage; 749 750 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 751 STAILQ_REMOVE_HEAD(&map->bpages, links); 752 free_bounce_page(dmat, bpage); 753 } 754} 755 756void 757_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 758{ 759 struct bounce_page *bpage; 760 761 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 762 /* 763 * Handle data bouncing. We might also 764 * want to add support for invalidating 765 * the caches on broken hardware 766 */ 767 if (op & BUS_DMASYNC_PREWRITE) { 768 while (bpage != NULL) { 769 bcopy((void *)bpage->datavaddr, 770 (void *)bpage->vaddr, 771 bpage->datacount); 772 bpage = STAILQ_NEXT(bpage, links); 773 } 774 } 775 776 if (op & BUS_DMASYNC_POSTREAD) { 777 while (bpage != NULL) { 778 bcopy((void *)bpage->vaddr, 779 (void *)bpage->datavaddr, 780 bpage->datacount); 781 bpage = STAILQ_NEXT(bpage, links); 782 } 783 } 784 } 785} 786 787static void 788init_bounce_pages(void *dummy __unused) 789{ 790 791 free_bpages = 0; 792 reserved_bpages = 0; 793 active_bpages = 0; 794 total_bpages = 0; 795 STAILQ_INIT(&bounce_page_list); 796 STAILQ_INIT(&bounce_map_waitinglist); 797 STAILQ_INIT(&bounce_map_callbacklist); 798 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 799} 800SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 801 802static int 803alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 804{ 805 int count; 806 807 count = 0; 808 while (numpages > 0) { 809 struct bounce_page *bpage; 810 811 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 812 M_NOWAIT | M_ZERO); 813 814 if (bpage == NULL) 815 break; 816 mtx_lock(&Giant); 817 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 818 M_NOWAIT, 0ul, 819 dmat->lowaddr, 820 PAGE_SIZE, 821 0); 822 mtx_unlock(&Giant); 823 if (bpage->vaddr == 0) { 824 free(bpage, M_DEVBUF); 825 break; 826 } 827 bpage->busaddr = pmap_kextract(bpage->vaddr); 828 mtx_lock(&bounce_lock); 829 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links); 830 total_bpages++; 831 free_bpages++; 832 mtx_unlock(&bounce_lock); 833 count++; 834 numpages--; 835 } 836 return (count); 837} 838 839static int 840reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 841{ 842 int pages; 843 844 mtx_assert(&bounce_lock, MA_OWNED); 845 pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved); 846 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 847 return (map->pagesneeded - (map->pagesreserved + pages)); 848 free_bpages -= pages; 849 reserved_bpages += pages; 850 map->pagesreserved += pages; 851 pages = map->pagesneeded - map->pagesreserved; 852 853 return (pages); 854} 855 856static bus_addr_t 857add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr, 858 bus_size_t size) 859{ 860 struct bounce_page *bpage; 861 862 KASSERT(map != NULL && map != &nobounce_dmamap, 863 ("add_bounce_page: bad map %p", map)); 864 865 if (map->pagesneeded == 0) 866 panic("add_bounce_page: map doesn't need any pages"); 867 map->pagesneeded--; 868 869 if (map->pagesreserved == 0) 870 panic("add_bounce_page: map doesn't need any pages"); 871 map->pagesreserved--; 872 873 mtx_lock(&bounce_lock); 874 bpage = STAILQ_FIRST(&bounce_page_list); 875 if (bpage == NULL) 876 panic("add_bounce_page: free page list is empty"); 877 878 STAILQ_REMOVE_HEAD(&bounce_page_list, links); 879 reserved_bpages--; 880 active_bpages++; 881 mtx_unlock(&bounce_lock); 882 883 bpage->datavaddr = vaddr; 884 bpage->datacount = size; 885 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 886 return (bpage->busaddr); 887} 888 889static void 890free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 891{ 892 struct bus_dmamap *map; 893 894 bpage->datavaddr = 0; 895 bpage->datacount = 0; 896 897 mtx_lock(&bounce_lock); 898 STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links); 899 free_bpages++; 900 active_bpages--; 901 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 902 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 903 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 904 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 905 map, links); 906 busdma_swi_pending = 1; 907 swi_sched(vm_ih, 0); 908 } 909 } 910 mtx_unlock(&bounce_lock); 911} 912 913void 914busdma_swi(void) 915{ 916 bus_dma_tag_t dmat; 917 struct bus_dmamap *map; 918 919 mtx_lock(&bounce_lock); 920 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 921 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 922 mtx_unlock(&bounce_lock); 923 dmat = (map)->dmat; 924 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK); 925 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 926 map->callback, map->callback_arg, /*flags*/0); 927 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK); 928 mtx_lock(&bounce_lock); 929 } 930 mtx_unlock(&bounce_lock); 931} 932