busdma_machdep.c revision 216194
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#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/i386/i386/busdma_machdep.c 216194 2010-12-05 03:20:55Z cperciva $"); 29 30#include <sys/param.h> 31#include <sys/systm.h> 32#include <sys/malloc.h> 33#include <sys/bus.h> 34#include <sys/interrupt.h> 35#include <sys/kernel.h> 36#include <sys/ktr.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#include <sys/sysctl.h> 43 44#include <vm/vm.h> 45#include <vm/vm_page.h> 46#include <vm/vm_map.h> 47 48#include <machine/atomic.h> 49#include <machine/bus.h> 50#include <machine/md_var.h> 51#include <machine/specialreg.h> 52 53#define MAX_BPAGES 512 54#define BUS_DMA_COULD_BOUNCE BUS_DMA_BUS3 55#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4 56 57struct bounce_zone; 58 59struct bus_dma_tag { 60 bus_dma_tag_t parent; 61 bus_size_t alignment; 62 bus_size_t boundary; 63 bus_addr_t lowaddr; 64 bus_addr_t highaddr; 65 bus_dma_filter_t *filter; 66 void *filterarg; 67 bus_size_t maxsize; 68 u_int nsegments; 69 bus_size_t maxsegsz; 70 int flags; 71 int ref_count; 72 int map_count; 73 bus_dma_lock_t *lockfunc; 74 void *lockfuncarg; 75 bus_dma_segment_t *segments; 76 struct bounce_zone *bounce_zone; 77}; 78 79struct bounce_page { 80 vm_offset_t vaddr; /* kva of bounce buffer */ 81 bus_addr_t busaddr; /* Physical address */ 82 vm_offset_t datavaddr; /* kva of client data */ 83 bus_size_t datacount; /* client data count */ 84 STAILQ_ENTRY(bounce_page) links; 85}; 86 87int busdma_swi_pending; 88 89struct bounce_zone { 90 STAILQ_ENTRY(bounce_zone) links; 91 STAILQ_HEAD(bp_list, bounce_page) bounce_page_list; 92 int total_bpages; 93 int free_bpages; 94 int reserved_bpages; 95 int active_bpages; 96 int total_bounced; 97 int total_deferred; 98 int map_count; 99 bus_size_t alignment; 100 bus_addr_t lowaddr; 101 char zoneid[8]; 102 char lowaddrid[20]; 103 struct sysctl_ctx_list sysctl_tree; 104 struct sysctl_oid *sysctl_tree_top; 105}; 106 107static struct mtx bounce_lock; 108static int total_bpages; 109static int busdma_zonecount; 110static STAILQ_HEAD(, bounce_zone) bounce_zone_list; 111 112SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters"); 113SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0, 114 "Total bounce pages"); 115 116struct bus_dmamap { 117 struct bp_list bpages; 118 int pagesneeded; 119 int pagesreserved; 120 bus_dma_tag_t dmat; 121 void *buf; /* unmapped buffer pointer */ 122 bus_size_t buflen; /* unmapped buffer length */ 123 bus_dmamap_callback_t *callback; 124 void *callback_arg; 125 STAILQ_ENTRY(bus_dmamap) links; 126}; 127 128static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist; 129static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist; 130static struct bus_dmamap nobounce_dmamap; 131 132static void init_bounce_pages(void *dummy); 133static int alloc_bounce_zone(bus_dma_tag_t dmat); 134static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages); 135static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, 136 int commit); 137static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, 138 vm_offset_t vaddr, bus_size_t size); 139static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage); 140int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr); 141int _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap, 142 void *buf, bus_size_t buflen, int flags); 143 144#ifdef XEN 145#undef pmap_kextract 146#define pmap_kextract pmap_kextract_ma 147#endif 148 149/* 150 * Return true if a match is made. 151 * 152 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'. 153 * 154 * If paddr is within the bounds of the dma tag then call the filter callback 155 * to check for a match, if there is no filter callback then assume a match. 156 */ 157int 158run_filter(bus_dma_tag_t dmat, bus_addr_t paddr) 159{ 160 int retval; 161 162 retval = 0; 163 164 do { 165 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) 166 || ((paddr & (dmat->alignment - 1)) != 0)) 167 && (dmat->filter == NULL 168 || (*dmat->filter)(dmat->filterarg, paddr) != 0)) 169 retval = 1; 170 171 dmat = dmat->parent; 172 } while (retval == 0 && dmat != NULL); 173 return (retval); 174} 175 176/* 177 * Convenience function for manipulating driver locks from busdma (during 178 * busdma_swi, for example). Drivers that don't provide their own locks 179 * should specify &Giant to dmat->lockfuncarg. Drivers that use their own 180 * non-mutex locking scheme don't have to use this at all. 181 */ 182void 183busdma_lock_mutex(void *arg, bus_dma_lock_op_t op) 184{ 185 struct mtx *dmtx; 186 187 dmtx = (struct mtx *)arg; 188 switch (op) { 189 case BUS_DMA_LOCK: 190 mtx_lock(dmtx); 191 break; 192 case BUS_DMA_UNLOCK: 193 mtx_unlock(dmtx); 194 break; 195 default: 196 panic("Unknown operation 0x%x for busdma_lock_mutex!", op); 197 } 198} 199 200/* 201 * dflt_lock should never get called. It gets put into the dma tag when 202 * lockfunc == NULL, which is only valid if the maps that are associated 203 * with the tag are meant to never be defered. 204 * XXX Should have a way to identify which driver is responsible here. 205 */ 206static void 207dflt_lock(void *arg, bus_dma_lock_op_t op) 208{ 209 panic("driver error: busdma dflt_lock called"); 210} 211 212/* 213 * Allocate a device specific dma_tag. 214 */ 215int 216bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment, 217 bus_size_t boundary, bus_addr_t lowaddr, 218 bus_addr_t highaddr, bus_dma_filter_t *filter, 219 void *filterarg, bus_size_t maxsize, int nsegments, 220 bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc, 221 void *lockfuncarg, bus_dma_tag_t *dmat) 222{ 223 bus_dma_tag_t newtag; 224 int error = 0; 225 226 /* Basic sanity checking */ 227 if (boundary != 0 && boundary < maxsegsz) 228 maxsegsz = boundary; 229 230 if (maxsegsz == 0) { 231 return (EINVAL); 232 } 233 234 /* Return a NULL tag on failure */ 235 *dmat = NULL; 236 237 newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, 238 M_ZERO | M_NOWAIT); 239 if (newtag == NULL) { 240 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 241 __func__, newtag, 0, error); 242 return (ENOMEM); 243 } 244 245 newtag->parent = parent; 246 newtag->alignment = alignment; 247 newtag->boundary = boundary; 248 newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1); 249 newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1); 250 newtag->filter = filter; 251 newtag->filterarg = filterarg; 252 newtag->maxsize = maxsize; 253 newtag->nsegments = nsegments; 254 newtag->maxsegsz = maxsegsz; 255 newtag->flags = flags; 256 newtag->ref_count = 1; /* Count ourself */ 257 newtag->map_count = 0; 258 if (lockfunc != NULL) { 259 newtag->lockfunc = lockfunc; 260 newtag->lockfuncarg = lockfuncarg; 261 } else { 262 newtag->lockfunc = dflt_lock; 263 newtag->lockfuncarg = NULL; 264 } 265 newtag->segments = NULL; 266 267 /* Take into account any restrictions imposed by our parent tag */ 268 if (parent != NULL) { 269 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr); 270 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr); 271 if (newtag->boundary == 0) 272 newtag->boundary = parent->boundary; 273 else if (parent->boundary != 0) 274 newtag->boundary = MIN(parent->boundary, 275 newtag->boundary); 276 if ((newtag->filter != NULL) || 277 ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0)) 278 newtag->flags |= BUS_DMA_COULD_BOUNCE; 279 if (newtag->filter == NULL) { 280 /* 281 * Short circuit looking at our parent directly 282 * since we have encapsulated all of its information 283 */ 284 newtag->filter = parent->filter; 285 newtag->filterarg = parent->filterarg; 286 newtag->parent = parent->parent; 287 } 288 if (newtag->parent != NULL) 289 atomic_add_int(&parent->ref_count, 1); 290 } 291 292 if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) 293 || newtag->alignment > 1) 294 newtag->flags |= BUS_DMA_COULD_BOUNCE; 295 296 if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) && 297 (flags & BUS_DMA_ALLOCNOW) != 0) { 298 struct bounce_zone *bz; 299 300 /* Must bounce */ 301 302 if ((error = alloc_bounce_zone(newtag)) != 0) { 303 free(newtag, M_DEVBUF); 304 return (error); 305 } 306 bz = newtag->bounce_zone; 307 308 if (ptoa(bz->total_bpages) < maxsize) { 309 int pages; 310 311 pages = atop(maxsize) - bz->total_bpages; 312 313 /* Add pages to our bounce pool */ 314 if (alloc_bounce_pages(newtag, pages) < pages) 315 error = ENOMEM; 316 } 317 /* Performed initial allocation */ 318 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP; 319 } 320 321 if (error != 0) { 322 free(newtag, M_DEVBUF); 323 } else { 324 *dmat = newtag; 325 } 326 CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d", 327 __func__, newtag, (newtag != NULL ? newtag->flags : 0), error); 328 return (error); 329} 330 331int 332bus_dma_tag_destroy(bus_dma_tag_t dmat) 333{ 334 bus_dma_tag_t dmat_copy; 335 int error; 336 337 error = 0; 338 dmat_copy = dmat; 339 340 if (dmat != NULL) { 341 342 if (dmat->map_count != 0) { 343 error = EBUSY; 344 goto out; 345 } 346 347 while (dmat != NULL) { 348 bus_dma_tag_t parent; 349 350 parent = dmat->parent; 351 atomic_subtract_int(&dmat->ref_count, 1); 352 if (dmat->ref_count == 0) { 353 if (dmat->segments != NULL) 354 free(dmat->segments, M_DEVBUF); 355 free(dmat, M_DEVBUF); 356 /* 357 * Last reference count, so 358 * release our reference 359 * count on our parent. 360 */ 361 dmat = parent; 362 } else 363 dmat = NULL; 364 } 365 } 366out: 367 CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error); 368 return (error); 369} 370 371/* 372 * Allocate a handle for mapping from kva/uva/physical 373 * address space into bus device space. 374 */ 375int 376bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp) 377{ 378 int error; 379 380 error = 0; 381 382 if (dmat->segments == NULL) { 383 dmat->segments = (bus_dma_segment_t *)malloc( 384 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 385 M_NOWAIT); 386 if (dmat->segments == NULL) { 387 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 388 __func__, dmat, ENOMEM); 389 return (ENOMEM); 390 } 391 } 392 393 /* 394 * Bouncing might be required if the driver asks for an active 395 * exclusion region, a data alignment that is stricter than 1, and/or 396 * an active address boundary. 397 */ 398 if (dmat->flags & BUS_DMA_COULD_BOUNCE) { 399 400 /* Must bounce */ 401 struct bounce_zone *bz; 402 int maxpages; 403 404 if (dmat->bounce_zone == NULL) { 405 if ((error = alloc_bounce_zone(dmat)) != 0) 406 return (error); 407 } 408 bz = dmat->bounce_zone; 409 410 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF, 411 M_NOWAIT | M_ZERO); 412 if (*mapp == NULL) { 413 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 414 __func__, dmat, ENOMEM); 415 return (ENOMEM); 416 } 417 418 /* Initialize the new map */ 419 STAILQ_INIT(&((*mapp)->bpages)); 420 421 /* 422 * Attempt to add pages to our pool on a per-instance 423 * basis up to a sane limit. 424 */ 425 if (dmat->alignment > 1) 426 maxpages = MAX_BPAGES; 427 else 428 maxpages = MIN(MAX_BPAGES, Maxmem -atop(dmat->lowaddr)); 429 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 430 || (bz->map_count > 0 && bz->total_bpages < maxpages)) { 431 int pages; 432 433 pages = MAX(atop(dmat->maxsize), 1); 434 pages = MIN(maxpages - bz->total_bpages, pages); 435 pages = MAX(pages, 1); 436 if (alloc_bounce_pages(dmat, pages) < pages) 437 error = ENOMEM; 438 439 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) { 440 if (error == 0) 441 dmat->flags |= BUS_DMA_MIN_ALLOC_COMP; 442 } else { 443 error = 0; 444 } 445 } 446 bz->map_count++; 447 } else { 448 *mapp = NULL; 449 } 450 if (error == 0) 451 dmat->map_count++; 452 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 453 __func__, dmat, dmat->flags, error); 454 return (error); 455} 456 457/* 458 * Destroy a handle for mapping from kva/uva/physical 459 * address space into bus device space. 460 */ 461int 462bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map) 463{ 464 if (map != NULL && map != &nobounce_dmamap) { 465 if (STAILQ_FIRST(&map->bpages) != NULL) { 466 CTR3(KTR_BUSDMA, "%s: tag %p error %d", 467 __func__, dmat, EBUSY); 468 return (EBUSY); 469 } 470 if (dmat->bounce_zone) 471 dmat->bounce_zone->map_count--; 472 free(map, M_DEVBUF); 473 } 474 dmat->map_count--; 475 CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat); 476 return (0); 477} 478 479 480/* 481 * Allocate a piece of memory that can be efficiently mapped into 482 * bus device space based on the constraints lited in the dma tag. 483 * A dmamap to for use with dmamap_load is also allocated. 484 */ 485int 486bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags, 487 bus_dmamap_t *mapp) 488{ 489 int mflags; 490 491 if (flags & BUS_DMA_NOWAIT) 492 mflags = M_NOWAIT; 493 else 494 mflags = M_WAITOK; 495 496 /* If we succeed, no mapping/bouncing will be required */ 497 *mapp = NULL; 498 499 if (dmat->segments == NULL) { 500 dmat->segments = (bus_dma_segment_t *)malloc( 501 sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF, 502 mflags); 503 if (dmat->segments == NULL) { 504 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 505 __func__, dmat, dmat->flags, ENOMEM); 506 return (ENOMEM); 507 } 508 } 509 if (flags & BUS_DMA_ZERO) 510 mflags |= M_ZERO; 511 512 /* 513 * XXX: 514 * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact 515 * alignment guarantees of malloc need to be nailed down, and the 516 * code below should be rewritten to take that into account. 517 * 518 * In the meantime, we'll warn the user if malloc gets it wrong. 519 */ 520 if ((dmat->maxsize <= PAGE_SIZE) && 521 (dmat->alignment < dmat->maxsize) && 522 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) { 523 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags); 524 } else { 525 /* 526 * XXX Use Contigmalloc until it is merged into this facility 527 * and handles multi-seg allocations. Nobody is doing 528 * multi-seg allocations yet though. 529 * XXX Certain AGP hardware does. 530 */ 531 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags, 532 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul, 533 dmat->boundary); 534 } 535 if (*vaddr == NULL) { 536 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 537 __func__, dmat, dmat->flags, ENOMEM); 538 return (ENOMEM); 539 } else if (vtophys(*vaddr) & (dmat->alignment - 1)) { 540 printf("bus_dmamem_alloc failed to align memory properly.\n"); 541 } 542 if (flags & BUS_DMA_NOCACHE) 543 pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize, 544 PAT_UNCACHEABLE); 545 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d", 546 __func__, dmat, dmat->flags, 0); 547 return (0); 548} 549 550/* 551 * Free a piece of memory and it's allociated dmamap, that was allocated 552 * via bus_dmamem_alloc. Make the same choice for free/contigfree. 553 */ 554void 555bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map) 556{ 557 /* 558 * dmamem does not need to be bounced, so the map should be 559 * NULL 560 */ 561 if (map != NULL) 562 panic("bus_dmamem_free: Invalid map freed\n"); 563 pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK); 564 if ((dmat->maxsize <= PAGE_SIZE) && 565 (dmat->alignment < dmat->maxsize) && 566 dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) 567 free(vaddr, M_DEVBUF); 568 else { 569 contigfree(vaddr, dmat->maxsize, M_DEVBUF); 570 } 571 CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags); 572} 573 574int 575_bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap, 576 void *buf, bus_size_t buflen, int flags) 577{ 578 vm_offset_t vaddr; 579 vm_offset_t vendaddr; 580 bus_addr_t paddr; 581 582 if ((map != &nobounce_dmamap && map->pagesneeded == 0)) { 583 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, " 584 "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem), 585 dmat->boundary, dmat->alignment); 586 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d", 587 map, &nobounce_dmamap, map->pagesneeded); 588 /* 589 * Count the number of bounce pages 590 * needed in order to complete this transfer 591 */ 592 vaddr = (vm_offset_t)buf; 593 vendaddr = (vm_offset_t)buf + buflen; 594 595 while (vaddr < vendaddr) { 596 bus_size_t sg_len; 597 598 sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK); 599 if (pmap) 600 paddr = pmap_extract(pmap, vaddr); 601 else 602 paddr = pmap_kextract(vaddr); 603 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) && 604 run_filter(dmat, paddr) != 0) { 605 sg_len = roundup2(sg_len, dmat->alignment); 606 map->pagesneeded++; 607 } 608 vaddr += sg_len; 609 } 610 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded); 611 } 612 613 /* Reserve Necessary Bounce Pages */ 614 if (map->pagesneeded != 0) { 615 mtx_lock(&bounce_lock); 616 if (flags & BUS_DMA_NOWAIT) { 617 if (reserve_bounce_pages(dmat, map, 0) != 0) { 618 mtx_unlock(&bounce_lock); 619 return (ENOMEM); 620 } 621 } else { 622 if (reserve_bounce_pages(dmat, map, 1) != 0) { 623 /* Queue us for resources */ 624 map->dmat = dmat; 625 map->buf = buf; 626 map->buflen = buflen; 627 STAILQ_INSERT_TAIL(&bounce_map_waitinglist, 628 map, links); 629 mtx_unlock(&bounce_lock); 630 return (EINPROGRESS); 631 } 632 } 633 mtx_unlock(&bounce_lock); 634 } 635 636 return (0); 637} 638 639/* 640 * Utility function to load a linear buffer. lastaddrp holds state 641 * between invocations (for multiple-buffer loads). segp contains 642 * the starting segment on entrace, and the ending segment on exit. 643 * first indicates if this is the first invocation of this function. 644 */ 645static __inline int 646_bus_dmamap_load_buffer(bus_dma_tag_t dmat, 647 bus_dmamap_t map, 648 void *buf, bus_size_t buflen, 649 pmap_t pmap, 650 int flags, 651 bus_addr_t *lastaddrp, 652 bus_dma_segment_t *segs, 653 int *segp, 654 int first) 655{ 656 bus_size_t sgsize; 657 bus_addr_t curaddr, lastaddr, baddr, bmask; 658 vm_offset_t vaddr; 659 int seg, error; 660 661 if (map == NULL) 662 map = &nobounce_dmamap; 663 664 if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) { 665 error = _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags); 666 if (error) 667 return (error); 668 } 669 670 vaddr = (vm_offset_t)buf; 671 lastaddr = *lastaddrp; 672 bmask = ~(dmat->boundary - 1); 673 674 for (seg = *segp; buflen > 0 ; ) { 675 bus_size_t max_sgsize; 676 677 /* 678 * Get the physical address for this segment. 679 */ 680 if (pmap) 681 curaddr = pmap_extract(pmap, vaddr); 682 else 683 curaddr = pmap_kextract(vaddr); 684 685 /* 686 * Compute the segment size, and adjust counts. 687 */ 688 max_sgsize = MIN(buflen, dmat->maxsegsz); 689 sgsize = PAGE_SIZE - ((vm_offset_t)curaddr & PAGE_MASK); 690 if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) && 691 map->pagesneeded != 0 && run_filter(dmat, curaddr)) { 692 sgsize = roundup2(sgsize, dmat->alignment); 693 sgsize = MIN(sgsize, max_sgsize); 694 curaddr = add_bounce_page(dmat, map, vaddr, sgsize); 695 } else { 696 sgsize = MIN(sgsize, max_sgsize); 697 } 698 699 /* 700 * Make sure we don't cross any boundaries. 701 */ 702 if (dmat->boundary > 0) { 703 baddr = (curaddr + dmat->boundary) & bmask; 704 if (sgsize > (baddr - curaddr)) 705 sgsize = (baddr - curaddr); 706 } 707 708 /* 709 * Insert chunk into a segment, coalescing with 710 * previous segment if possible. 711 */ 712 if (first) { 713 segs[seg].ds_addr = curaddr; 714 segs[seg].ds_len = sgsize; 715 first = 0; 716 } else { 717 if (curaddr == lastaddr && 718 (segs[seg].ds_len + sgsize) <= dmat->maxsegsz && 719 (dmat->boundary == 0 || 720 (segs[seg].ds_addr & bmask) == (curaddr & bmask))) 721 segs[seg].ds_len += sgsize; 722 else { 723 if (++seg >= dmat->nsegments) 724 break; 725 segs[seg].ds_addr = curaddr; 726 segs[seg].ds_len = sgsize; 727 } 728 } 729 730 lastaddr = curaddr + sgsize; 731 vaddr += sgsize; 732 buflen -= sgsize; 733 } 734 735 *segp = seg; 736 *lastaddrp = lastaddr; 737 738 /* 739 * Did we fit? 740 */ 741 return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */ 742} 743 744/* 745 * Map the buffer buf into bus space using the dmamap map. 746 */ 747int 748bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf, 749 bus_size_t buflen, bus_dmamap_callback_t *callback, 750 void *callback_arg, int flags) 751{ 752 bus_addr_t lastaddr = 0; 753 int error, nsegs = 0; 754 755 if (map != NULL) { 756 flags |= BUS_DMA_WAITOK; 757 map->callback = callback; 758 map->callback_arg = callback_arg; 759 } 760 761 error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags, 762 &lastaddr, dmat->segments, &nsegs, 1); 763 764 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 765 __func__, dmat, dmat->flags, error, nsegs + 1); 766 767 if (error == EINPROGRESS) { 768 return (error); 769 } 770 771 if (error) 772 (*callback)(callback_arg, dmat->segments, 0, error); 773 else 774 (*callback)(callback_arg, dmat->segments, nsegs + 1, 0); 775 776 /* 777 * Return ENOMEM to the caller so that it can pass it up the stack. 778 * This error only happens when NOWAIT is set, so deferal is disabled. 779 */ 780 if (error == ENOMEM) 781 return (error); 782 783 return (0); 784} 785 786 787/* 788 * Like _bus_dmamap_load(), but for mbufs. 789 */ 790static __inline int 791_bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 792 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 793 int flags) 794{ 795 int error; 796 797 M_ASSERTPKTHDR(m0); 798 799 flags |= BUS_DMA_NOWAIT; 800 *nsegs = 0; 801 error = 0; 802 if (m0->m_pkthdr.len <= dmat->maxsize) { 803 int first = 1; 804 bus_addr_t lastaddr = 0; 805 struct mbuf *m; 806 807 for (m = m0; m != NULL && error == 0; m = m->m_next) { 808 if (m->m_len > 0) { 809 error = _bus_dmamap_load_buffer(dmat, map, 810 m->m_data, m->m_len, 811 NULL, flags, &lastaddr, 812 segs, nsegs, first); 813 first = 0; 814 } 815 } 816 } else { 817 error = EINVAL; 818 } 819 820 /* XXX FIXME: Having to increment nsegs is really annoying */ 821 ++*nsegs; 822 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 823 __func__, dmat, dmat->flags, error, *nsegs); 824 return (error); 825} 826 827int 828bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, 829 struct mbuf *m0, 830 bus_dmamap_callback2_t *callback, void *callback_arg, 831 int flags) 832{ 833 int nsegs, error; 834 835 error = _bus_dmamap_load_mbuf_sg(dmat, map, m0, dmat->segments, &nsegs, 836 flags); 837 838 if (error) { 839 /* force "no valid mappings" in callback */ 840 (*callback)(callback_arg, dmat->segments, 0, 0, error); 841 } else { 842 (*callback)(callback_arg, dmat->segments, 843 nsegs, m0->m_pkthdr.len, error); 844 } 845 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 846 __func__, dmat, dmat->flags, error, nsegs); 847 return (error); 848} 849 850int 851bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, 852 struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs, 853 int flags) 854{ 855 return (_bus_dmamap_load_mbuf_sg(dmat, map, m0, segs, nsegs, flags)); 856} 857 858/* 859 * Like _bus_dmamap_load(), but for uios. 860 */ 861int 862bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, 863 struct uio *uio, 864 bus_dmamap_callback2_t *callback, void *callback_arg, 865 int flags) 866{ 867 bus_addr_t lastaddr = 0; 868 int nsegs, error, first, i; 869 bus_size_t resid; 870 struct iovec *iov; 871 pmap_t pmap; 872 873 flags |= BUS_DMA_NOWAIT; 874 resid = uio->uio_resid; 875 iov = uio->uio_iov; 876 877 if (uio->uio_segflg == UIO_USERSPACE) { 878 KASSERT(uio->uio_td != NULL, 879 ("bus_dmamap_load_uio: USERSPACE but no proc")); 880 pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace); 881 } else 882 pmap = NULL; 883 884 nsegs = 0; 885 error = 0; 886 first = 1; 887 for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) { 888 /* 889 * Now at the first iovec to load. Load each iovec 890 * until we have exhausted the residual count. 891 */ 892 bus_size_t minlen = 893 resid < iov[i].iov_len ? resid : iov[i].iov_len; 894 caddr_t addr = (caddr_t) iov[i].iov_base; 895 896 if (minlen > 0) { 897 error = _bus_dmamap_load_buffer(dmat, map, 898 addr, minlen, pmap, flags, &lastaddr, 899 dmat->segments, &nsegs, first); 900 first = 0; 901 902 resid -= minlen; 903 } 904 } 905 906 if (error) { 907 /* force "no valid mappings" in callback */ 908 (*callback)(callback_arg, dmat->segments, 0, 0, error); 909 } else { 910 (*callback)(callback_arg, dmat->segments, 911 nsegs+1, uio->uio_resid, error); 912 } 913 CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d", 914 __func__, dmat, dmat->flags, error, nsegs + 1); 915 return (error); 916} 917 918/* 919 * Release the mapping held by map. 920 */ 921void 922_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map) 923{ 924 struct bounce_page *bpage; 925 926 while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 927 STAILQ_REMOVE_HEAD(&map->bpages, links); 928 free_bounce_page(dmat, bpage); 929 } 930} 931 932void 933_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op) 934{ 935 struct bounce_page *bpage; 936 937 if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { 938 /* 939 * Handle data bouncing. We might also 940 * want to add support for invalidating 941 * the caches on broken hardware 942 */ 943 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x " 944 "performing bounce", __func__, op, dmat, dmat->flags); 945 946 if (op & BUS_DMASYNC_PREWRITE) { 947 while (bpage != NULL) { 948 bcopy((void *)bpage->datavaddr, 949 (void *)bpage->vaddr, 950 bpage->datacount); 951 bpage = STAILQ_NEXT(bpage, links); 952 } 953 dmat->bounce_zone->total_bounced++; 954 } 955 956 if (op & BUS_DMASYNC_POSTREAD) { 957 while (bpage != NULL) { 958 bcopy((void *)bpage->vaddr, 959 (void *)bpage->datavaddr, 960 bpage->datacount); 961 bpage = STAILQ_NEXT(bpage, links); 962 } 963 dmat->bounce_zone->total_bounced++; 964 } 965 } 966} 967 968static void 969init_bounce_pages(void *dummy __unused) 970{ 971 972 total_bpages = 0; 973 STAILQ_INIT(&bounce_zone_list); 974 STAILQ_INIT(&bounce_map_waitinglist); 975 STAILQ_INIT(&bounce_map_callbacklist); 976 mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF); 977} 978SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL); 979 980static struct sysctl_ctx_list * 981busdma_sysctl_tree(struct bounce_zone *bz) 982{ 983 return (&bz->sysctl_tree); 984} 985 986static struct sysctl_oid * 987busdma_sysctl_tree_top(struct bounce_zone *bz) 988{ 989 return (bz->sysctl_tree_top); 990} 991 992static int 993alloc_bounce_zone(bus_dma_tag_t dmat) 994{ 995 struct bounce_zone *bz; 996 997 /* Check to see if we already have a suitable zone */ 998 STAILQ_FOREACH(bz, &bounce_zone_list, links) { 999 if ((dmat->alignment <= bz->alignment) 1000 && (dmat->lowaddr >= bz->lowaddr)) { 1001 dmat->bounce_zone = bz; 1002 return (0); 1003 } 1004 } 1005 1006 if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF, 1007 M_NOWAIT | M_ZERO)) == NULL) 1008 return (ENOMEM); 1009 1010 STAILQ_INIT(&bz->bounce_page_list); 1011 bz->free_bpages = 0; 1012 bz->reserved_bpages = 0; 1013 bz->active_bpages = 0; 1014 bz->lowaddr = dmat->lowaddr; 1015 bz->alignment = MAX(dmat->alignment, PAGE_SIZE); 1016 bz->map_count = 0; 1017 snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount); 1018 busdma_zonecount++; 1019 snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr); 1020 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links); 1021 dmat->bounce_zone = bz; 1022 1023 sysctl_ctx_init(&bz->sysctl_tree); 1024 bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree, 1025 SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid, 1026 CTLFLAG_RD, 0, ""); 1027 if (bz->sysctl_tree_top == NULL) { 1028 sysctl_ctx_free(&bz->sysctl_tree); 1029 return (0); /* XXX error code? */ 1030 } 1031 1032 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1033 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1034 "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0, 1035 "Total bounce pages"); 1036 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1037 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1038 "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0, 1039 "Free bounce pages"); 1040 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1041 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1042 "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0, 1043 "Reserved bounce pages"); 1044 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1045 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1046 "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0, 1047 "Active bounce pages"); 1048 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1049 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1050 "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0, 1051 "Total bounce requests"); 1052 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1053 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1054 "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0, 1055 "Total bounce requests that were deferred"); 1056 SYSCTL_ADD_STRING(busdma_sysctl_tree(bz), 1057 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1058 "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, ""); 1059 SYSCTL_ADD_INT(busdma_sysctl_tree(bz), 1060 SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO, 1061 "alignment", CTLFLAG_RD, &bz->alignment, 0, ""); 1062 1063 return (0); 1064} 1065 1066static int 1067alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages) 1068{ 1069 struct bounce_zone *bz; 1070 int count; 1071 1072 bz = dmat->bounce_zone; 1073 count = 0; 1074 while (numpages > 0) { 1075 struct bounce_page *bpage; 1076 1077 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF, 1078 M_NOWAIT | M_ZERO); 1079 1080 if (bpage == NULL) 1081 break; 1082 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF, 1083 M_NOWAIT, 0ul, 1084 bz->lowaddr, 1085 PAGE_SIZE, 1086 0); 1087 if (bpage->vaddr == 0) { 1088 free(bpage, M_DEVBUF); 1089 break; 1090 } 1091 bpage->busaddr = pmap_kextract(bpage->vaddr); 1092 mtx_lock(&bounce_lock); 1093 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links); 1094 total_bpages++; 1095 bz->total_bpages++; 1096 bz->free_bpages++; 1097 mtx_unlock(&bounce_lock); 1098 count++; 1099 numpages--; 1100 } 1101 return (count); 1102} 1103 1104static int 1105reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit) 1106{ 1107 struct bounce_zone *bz; 1108 int pages; 1109 1110 mtx_assert(&bounce_lock, MA_OWNED); 1111 bz = dmat->bounce_zone; 1112 pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved); 1113 if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages)) 1114 return (map->pagesneeded - (map->pagesreserved + pages)); 1115 bz->free_bpages -= pages; 1116 bz->reserved_bpages += pages; 1117 map->pagesreserved += pages; 1118 pages = map->pagesneeded - map->pagesreserved; 1119 1120 return (pages); 1121} 1122 1123static bus_addr_t 1124add_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; 1128 struct bounce_page *bpage; 1129 1130 KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag")); 1131 KASSERT(map != NULL && map != &nobounce_dmamap, 1132 ("add_bounce_page: bad map %p", map)); 1133 1134 bz = dmat->bounce_zone; 1135 if (map->pagesneeded == 0) 1136 panic("add_bounce_page: map doesn't need any pages"); 1137 map->pagesneeded--; 1138 1139 if (map->pagesreserved == 0) 1140 panic("add_bounce_page: map doesn't need any pages"); 1141 map->pagesreserved--; 1142 1143 mtx_lock(&bounce_lock); 1144 bpage = STAILQ_FIRST(&bz->bounce_page_list); 1145 if (bpage == NULL) 1146 panic("add_bounce_page: free page list is empty"); 1147 1148 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links); 1149 bz->reserved_bpages--; 1150 bz->active_bpages++; 1151 mtx_unlock(&bounce_lock); 1152 1153 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) { 1154 /* Page offset needs to be preserved. */ 1155 bpage->vaddr |= vaddr & PAGE_MASK; 1156 bpage->busaddr |= vaddr & PAGE_MASK; 1157 } 1158 bpage->datavaddr = vaddr; 1159 bpage->datacount = size; 1160 STAILQ_INSERT_TAIL(&(map->bpages), bpage, links); 1161 return (bpage->busaddr); 1162} 1163 1164static void 1165free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage) 1166{ 1167 struct bus_dmamap *map; 1168 struct bounce_zone *bz; 1169 1170 bz = dmat->bounce_zone; 1171 bpage->datavaddr = 0; 1172 bpage->datacount = 0; 1173 if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) { 1174 /* 1175 * Reset the bounce page to start at offset 0. Other uses 1176 * of this bounce page may need to store a full page of 1177 * data and/or assume it starts on a page boundary. 1178 */ 1179 bpage->vaddr &= ~PAGE_MASK; 1180 bpage->busaddr &= ~PAGE_MASK; 1181 } 1182 1183 mtx_lock(&bounce_lock); 1184 STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links); 1185 bz->free_bpages++; 1186 bz->active_bpages--; 1187 if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) { 1188 if (reserve_bounce_pages(map->dmat, map, 1) == 0) { 1189 STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links); 1190 STAILQ_INSERT_TAIL(&bounce_map_callbacklist, 1191 map, links); 1192 busdma_swi_pending = 1; 1193 bz->total_deferred++; 1194 swi_sched(vm_ih, 0); 1195 } 1196 } 1197 mtx_unlock(&bounce_lock); 1198} 1199 1200void 1201busdma_swi(void) 1202{ 1203 bus_dma_tag_t dmat; 1204 struct bus_dmamap *map; 1205 1206 mtx_lock(&bounce_lock); 1207 while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) { 1208 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links); 1209 mtx_unlock(&bounce_lock); 1210 dmat = map->dmat; 1211 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK); 1212 bus_dmamap_load(map->dmat, map, map->buf, map->buflen, 1213 map->callback, map->callback_arg, /*flags*/0); 1214 (dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK); 1215 mtx_lock(&bounce_lock); 1216 } 1217 mtx_unlock(&bounce_lock); 1218} 1219