sys/platform/pc32/i386/busdma_machdep.c

   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: src/sys/i386/i386/busdma_machdep.c,v 1.16.2.2 2003/01/23 00:55:27 scottl Exp $
  27  * $DragonFly: src/sys/platform/pc32/i386/busdma_machdep.c,v 1.4 2003/07/27 01:49:51 hmp Exp $
  28  */
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/malloc.h>
  33 #include <sys/mbuf.h>
  34 #include <sys/uio.h>
  35
  36 #include <vm/vm.h>
  37 #include <vm/vm_page.h>
  38
  39 /* XXX needed for to access pmap to convert per-proc virtual to physical */
  40 #include <sys/proc.h>
  41 #include <sys/lock.h>
  42 #include <vm/vm_map.h>
  43
  44 #include <machine/bus.h>
  45 #include <machine/md_var.h>
  46
  47 #define MAX_BPAGES 128
  48
  49 struct bus_dma_tag {
  50         bus_dma_tag_t     parent;
  51         bus_size_t        alignment;
  52         bus_size_t        boundary;
  53         bus_addr_t        lowaddr;
  54         bus_addr_t        highaddr;
  55         bus_dma_filter_t *filter;
  56         void             *filterarg;
  57         bus_size_t        maxsize;
  58         u_int             nsegments;
  59         bus_size_t        maxsegsz;
  60         int               flags;
  61         int               ref_count;
  62         int               map_count;
  63 };
  64
  65 struct bounce_page {
  66         vm_offset_t     vaddr;          /* kva of bounce buffer */
  67         bus_addr_t      busaddr;        /* Physical address */
  68         vm_offset_t     datavaddr;      /* kva of client data */
  69         bus_size_t      datacount;      /* client data count */
  70         STAILQ_ENTRY(bounce_page) links;
  71 };
  72
  73 int busdma_swi_pending;
  74
  75 static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  76 static int free_bpages;
  77 static int reserved_bpages;
  78 static int active_bpages;
  79 static int total_bpages;
  80 static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
  81
  82 struct bus_dmamap {
  83         struct bp_list         bpages;
  84         int                    pagesneeded;
  85         int                    pagesreserved;
  86         bus_dma_tag_t          dmat;
  87         void                  *buf;             /* unmapped buffer pointer */
  88         bus_size_t             buflen;          /* unmapped buffer length */
  89         bus_dmamap_callback_t *callback;
  90         void                  *callback_arg;
  91         STAILQ_ENTRY(bus_dmamap) links;
  92 };
  93
  94 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
  95 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
  96 static struct bus_dmamap nobounce_dmamap;
  97
  98 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
  99 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map);
 100 static vm_offset_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 101                                    vm_offset_t vaddr, bus_size_t size);
 102 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 103 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 104
 105 static __inline int
 106 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 107 {
 108         int retval;
 109
 110         retval = 0;
 111         do {
 112                 if (paddr > dmat->lowaddr
 113                  && paddr <= dmat->highaddr
 114                  && (dmat->filter == NULL
 115                   || (*dmat->filter)(dmat->filterarg, paddr) != 0))
 116                         retval = 1;
 117
 118                 dmat = dmat->parent;
 119         } while (retval == 0 && dmat != NULL);
 120         return (retval);
 121 }
 122
 123 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
 124 /*
 125  * Allocate a device specific dma_tag.
 126  */
 127 int
 128 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 129                    bus_size_t boundary, bus_addr_t lowaddr,
 130                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 131                    void *filterarg, bus_size_t maxsize, int nsegments,
 132                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 133 {
 134         bus_dma_tag_t newtag;
 135         int error = 0;
 136
 137         /* Return a NULL tag on failure */
 138         *dmat = NULL;
 139
 140         newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
 141         if (newtag == NULL)
 142                 return (ENOMEM);
 143
 144         newtag->parent = parent;
 145         newtag->alignment = alignment;
 146         newtag->boundary = boundary;
 147         newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
 148         newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
 149         newtag->filter = filter;
 150         newtag->filterarg = filterarg;
 151         newtag->maxsize = maxsize;
 152         newtag->nsegments = nsegments;
 153         newtag->maxsegsz = maxsegsz;
 154         newtag->flags = flags;
 155         newtag->ref_count = 1; /* Count ourself */
 156         newtag->map_count = 0;
 157
 158         /* Take into account any restrictions imposed by our parent tag */
 159         if (parent != NULL) {
 160                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 161                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 162                 /*
 163                  * XXX Not really correct??? Probably need to honor boundary
 164                  *     all the way up the inheritence chain.
 165                  */
 166                 newtag->boundary = MAX(parent->boundary, newtag->boundary);
 167                 if (newtag->filter == NULL) {
 168                         /*
 169                          * Short circuit looking at our parent directly
 170                          * since we have encapsulated all of its information
 171                          */
 172                         newtag->filter = parent->filter;
 173                         newtag->filterarg = parent->filterarg;
 174                         newtag->parent = parent->parent;
 175                 }
 176                 if (newtag->parent != NULL) {
 177                         parent->ref_count++;
 178                 }
 179         }
 180
 181         if (newtag->lowaddr < ptoa(Maxmem) && (flags & BUS_DMA_ALLOCNOW) != 0) {
 182                 /* Must bounce */
 183
 184                 if (lowaddr > bounce_lowaddr) {
 185                         /*
 186                          * Go through the pool and kill any pages
 187                          * that don't reside below lowaddr.
 188                          */
 189                         panic("bus_dma_tag_create: page reallocation "
 190                               "not implemented");
 191                 }
 192                 if (ptoa(total_bpages) < maxsize) {
 193                         int pages;
 194
 195                         pages = atop(maxsize) - total_bpages;
 196
 197                         /* Add pages to our bounce pool */
 198                         if (alloc_bounce_pages(newtag, pages) < pages)
 199                                 error = ENOMEM;
 200                 }
 201                 /* Performed initial allocation */
 202                 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 203         }
 204
 205         if (error != 0) {
 206                 free(newtag, M_DEVBUF);
 207         } else {
 208                 *dmat = newtag;
 209         }
 210         return (error);
 211 }
 212
 213 int
 214 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 215 {
 216         if (dmat != NULL) {
 217
 218                 if (dmat->map_count != 0)
 219                         return (EBUSY);
 220
 221                 while (dmat != NULL) {
 222                         bus_dma_tag_t parent;
 223
 224                         parent = dmat->parent;
 225                         dmat->ref_count--;
 226                         if (dmat->ref_count == 0) {
 227                                 free(dmat, M_DEVBUF);
 228                                 /*
 229                                  * Last reference count, so
 230                                  * release our reference
 231                                  * count on our parent.
 232                                  */
 233                                 dmat = parent;
 234                         } else
 235                                 dmat = NULL;
 236                 }
 237         }
 238         return (0);
 239 }
 240
 241 /*
 242  * Allocate a handle for mapping from kva/uva/physical
 243  * address space into bus device space.
 244  */
 245 int
 246 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 247 {
 248         int error;
 249
 250         error = 0;
 251
 252         if (dmat->lowaddr < ptoa(Maxmem)) {
 253                 /* Must bounce */
 254                 int maxpages;
 255
 256                 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 257                                              M_NOWAIT);
 258                 if (*mapp == NULL) {
 259                         return (ENOMEM);
 260                 } else {
 261                         /* Initialize the new map */
 262                         bzero(*mapp, sizeof(**mapp));
 263                         STAILQ_INIT(&((*mapp)->bpages));
 264                 }
 265                 /*
 266                  * Attempt to add pages to our pool on a per-instance
 267                  * basis up to a sane limit.
 268                  */
 269                 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
 270                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
 271                  || (dmat->map_count > 0
 272                   && total_bpages < maxpages)) {
 273                         int pages;
 274
 275                         if (dmat->lowaddr > bounce_lowaddr) {
 276                                 /*
 277                                  * Go through the pool and kill any pages
 278                                  * that don't reside below lowaddr.
 279                                  */
 280                                 panic("bus_dmamap_create: page reallocation "
 281                                       "not implemented");
 282                         }
 283                         pages = atop(dmat->maxsize);
 284                         pages = MIN(maxpages - total_bpages, pages);
 285                         error = alloc_bounce_pages(dmat, pages);
 286
 287                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 288                                 if (error == 0)
 289                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 290                         } else {
 291                                 error = 0;
 292                         }
 293                 }
 294         } else {
 295                 *mapp = NULL;
 296         }
 297         if (error == 0)
 298                 dmat->map_count++;
 299         return (error);
 300 }
 301
 302 /*
 303  * Destroy a handle for mapping from kva/uva/physical
 304  * address space into bus device space.
 305  */
 306 int
 307 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 308 {
 309         if (map != NULL) {
 310                 if (STAILQ_FIRST(&map->bpages) != NULL)
 311                         return (EBUSY);
 312                 free(map, M_DEVBUF);
 313         }
 314         dmat->map_count--;
 315         return (0);
 316 }
 317
 318
 319 /*
 320  * Allocate a piece of memory that can be efficiently mapped into
 321  * bus device space based on the constraints lited in the dma tag.
 322  * A dmamap to for use with dmamap_load is also allocated.
 323  */
 324 int
 325 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 326                  bus_dmamap_t *mapp)
 327 {
 328         /* If we succeed, no mapping/bouncing will be required */
 329         *mapp = NULL;
 330
 331         if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem)) {
 332                 *vaddr = malloc(dmat->maxsize, M_DEVBUF,
 333                                 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK);
 334         } else {
 335                 /*
 336                  * XXX Use Contigmalloc until it is merged into this facility
 337                  *     and handles multi-seg allocations.  Nobody is doing
 338                  *     multi-seg allocations yet though.
 339                  */
 340                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF,
 341                     (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK,
 342                     0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
 343                     dmat->boundary);
 344         }
 345         if (*vaddr == NULL)
 346                 return (ENOMEM);
 347         return (0);
 348 }
 349
 350 /*
 351  * Free a piece of memory and it's allociated dmamap, that was allocated
 352  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 353  */
 354 void
 355 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 356 {
 357         /*
 358          * dmamem does not need to be bounced, so the map should be
 359          * NULL
 360          */
 361         if (map != NULL)
 362                 panic("bus_dmamem_free: Invalid map freed\n");
 363         if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem))
 364                 free(vaddr, M_DEVBUF);
 365         else
 366                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 367 }
 368
 369 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
 370
 371 /*
 372  * Map the buffer buf into bus space using the dmamap map.
 373  */
 374 int
 375 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 376                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 377                 void *callback_arg, int flags)
 378 {
 379         vm_offset_t             vaddr;
 380         vm_offset_t             paddr;
 381 #ifdef __GNUC__
 382         bus_dma_segment_t       dm_segments[dmat->nsegments];
 383 #else
 384         bus_dma_segment_t       dm_segments[BUS_DMAMAP_NSEGS];
 385 #endif
 386         bus_dma_segment_t      *sg;
 387         int                     seg;
 388         int                     error;
 389         vm_offset_t             nextpaddr;
 390
 391         if (map == NULL)
 392                 map = &nobounce_dmamap;
 393
 394         error = 0;
 395         /*
 396          * If we are being called during a callback, pagesneeded will
 397          * be non-zero, so we can avoid doing the work twice.
 398          */
 399         if (dmat->lowaddr < ptoa(Maxmem) && map->pagesneeded == 0) {
 400                 vm_offset_t     vendaddr;
 401
 402                 /*
 403                  * Count the number of bounce pages
 404                  * needed in order to complete this transfer
 405                  */
 406                 vaddr = trunc_page((vm_offset_t)buf);
 407                 vendaddr = (vm_offset_t)buf + buflen;
 408
 409                 while (vaddr < vendaddr) {
 410                         paddr = pmap_kextract(vaddr);
 411                         if (run_filter(dmat, paddr) != 0) {
 412
 413                                 map->pagesneeded++;
 414                         }
 415                         vaddr += PAGE_SIZE;
 416                 }
 417         }
 418
 419         /* Reserve Necessary Bounce Pages */
 420         if (map->pagesneeded != 0) {
 421                 int s;
 422
 423                 s = splhigh();
 424                 if (reserve_bounce_pages(dmat, map) != 0) {
 425
 426                         /* Queue us for resources */
 427                         map->dmat = dmat;
 428                         map->buf = buf;
 429                         map->buflen = buflen;
 430                         map->callback = callback;
 431                         map->callback_arg = callback_arg;
 432
 433                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 434                         splx(s);
 435
 436                         return (EINPROGRESS);
 437                 }
 438                 splx(s);
 439         }
 440
 441         vaddr = (vm_offset_t)buf;
 442         sg = &dm_segments[0];
 443         seg = 1;
 444         sg->ds_len = 0;
 445
 446         nextpaddr = 0;
 447         do {
 448                 bus_size_t      size;
 449
 450                 paddr = pmap_kextract(vaddr);
 451                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 452                 if (size > buflen)
 453                         size = buflen;
 454
 455                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 456                         paddr = add_bounce_page(dmat, map, vaddr, size);
 457                 }
 458
 459                 if (sg->ds_len == 0) {
 460                         sg->ds_addr = paddr;
 461                         sg->ds_len = size;
 462                 } else if (paddr == nextpaddr) {
 463                         sg->ds_len += size;
 464                 } else {
 465                         /* Go to the next segment */
 466                         sg++;
 467                         seg++;
 468                         if (seg > dmat->nsegments)
 469                                 break;
 470                         sg->ds_addr = paddr;
 471                         sg->ds_len = size;
 472                 }
 473                 vaddr += size;
 474                 nextpaddr = paddr + size;
 475                 buflen -= size;
 476
 477         } while (buflen > 0);
 478
 479         if (buflen != 0) {
 480                 printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
 481                        (u_long)buflen);
 482                 error = EFBIG;
 483         }
 484
 485         (*callback)(callback_arg, dm_segments, seg, error);
 486
 487         return (0);
 488 }
 489
 490 /*
 491  * Utility function to load a linear buffer.  lastaddrp holds state
 492  * between invocations (for multiple-buffer loads).  segp contains
 493  * the starting segment on entrace, and the ending segment on exit.
 494  * first indicates if this is the first invocation of this function.
 495  */
 496 static int
 497 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 498                         bus_dma_segment_t segs[],
 499                         void *buf, bus_size_t buflen,
 500                         struct thread *td,
 501                         int flags,
 502                         vm_offset_t *lastaddrp,
 503                         int *segp,
 504                         int first)
 505 {
 506         bus_size_t sgsize;
 507         bus_addr_t curaddr, lastaddr, baddr, bmask;
 508         vm_offset_t vaddr = (vm_offset_t)buf;
 509         int seg;
 510         pmap_t pmap;
 511
 512         if (td->td_proc != NULL)
 513                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 514         else
 515                 pmap = NULL;
 516
 517         lastaddr = *lastaddrp;
 518         bmask  = ~(dmat->boundary - 1);
 519
 520         for (seg = *segp; buflen > 0 ; ) {
 521                 /*
 522                  * Get the physical address for this segment.
 523                  */
 524                 if (pmap)
 525                         curaddr = pmap_extract(pmap, vaddr);
 526                 else
 527                         curaddr = pmap_kextract(vaddr);
 528
 529                 /*
 530                  * Compute the segment size, and adjust counts.
 531                  */
 532                 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
 533                 if (buflen < sgsize)
 534                         sgsize = buflen;
 535
 536                 /*
 537                  * Make sure we don't cross any boundaries.
 538                  */
 539                 if (dmat->boundary > 0) {
 540                         baddr = (curaddr + dmat->boundary) & bmask;
 541                         if (sgsize > (baddr - curaddr))
 542                                 sgsize = (baddr - curaddr);
 543                 }
 544
 545                 /*
 546                  * Insert chunk into a segment, coalescing with
 547                  * previous segment if possible.
 548                  */
 549                 if (first) {
 550                         segs[seg].ds_addr = curaddr;
 551                         segs[seg].ds_len = sgsize;
 552                         first = 0;
 553                 } else {
 554                         if (curaddr == lastaddr &&
 555                             (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
 556                             (dmat->boundary == 0 ||
 557                              (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 558                                 segs[seg].ds_len += sgsize;
 559                         else {
 560                                 if (++seg >= dmat->nsegments)
 561                                         break;
 562                                 segs[seg].ds_addr = curaddr;
 563                                 segs[seg].ds_len = sgsize;
 564                         }
 565                 }
 566
 567                 lastaddr = curaddr + sgsize;
 568                 vaddr += sgsize;
 569                 buflen -= sgsize;
 570         }
 571
 572         *segp = seg;
 573         *lastaddrp = lastaddr;
 574
 575         /*
 576          * Did we fit?
 577          */
 578         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 579 }
 580
 581 /*
 582  * Like _bus_dmamap_load(), but for mbufs.
 583  */
 584 int
 585 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 586                      struct mbuf *m0,
 587                      bus_dmamap_callback2_t *callback, void *callback_arg,
 588                      int flags)
 589 {
 590 #ifdef __GNUC__
 591         bus_dma_segment_t dm_segments[dmat->nsegments];
 592 #else
 593         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
 594 #endif
 595         int nsegs, error;
 596
 597         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 598                 ("bus_dmamap_load_mbuf: No support for bounce pages!"));
 599         KASSERT(m0->m_flags & M_PKTHDR,
 600                 ("bus_dmamap_load_mbuf: no packet header"));
 601
 602         nsegs = 0;
 603         error = 0;
 604         if (m0->m_pkthdr.len <= dmat->maxsize) {
 605                 int first = 1;
 606                 vm_offset_t lastaddr = 0;
 607                 struct mbuf *m;
 608
 609                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 610                         error = _bus_dmamap_load_buffer(dmat,
 611                                         dm_segments,
 612                                         m->m_data, m->m_len,
 613                                         NULL, flags, &lastaddr, &nsegs, first);
 614                         first = 0;
 615                 }
 616         } else {
 617                 error = EINVAL;
 618         }
 619
 620         if (error) {
 621                 /* force "no valid mappings" in callback */
 622                 (*callback)(callback_arg, dm_segments, 0, 0, error);
 623         } else {
 624                 (*callback)(callback_arg, dm_segments,
 625                             nsegs+1, m0->m_pkthdr.len, error);
 626         }
 627         return (error);
 628 }
 629
 630 /*
 631  * Like _bus_dmamap_load(), but for uios.
 632  */
 633 int
 634 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 635                     struct uio *uio,
 636                     bus_dmamap_callback2_t *callback, void *callback_arg,
 637                     int flags)
 638 {
 639         vm_offset_t lastaddr;
 640 #ifdef __GNUC__
 641         bus_dma_segment_t dm_segments[dmat->nsegments];
 642 #else
 643         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
 644 #endif
 645         int nsegs, error, first, i;
 646         bus_size_t resid;
 647         struct iovec *iov;
 648         struct thread *td = NULL;
 649
 650         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 651                 ("bus_dmamap_load_uio: No support for bounce pages!"));
 652
 653         resid = uio->uio_resid;
 654         iov = uio->uio_iov;
 655
 656         if (uio->uio_segflg == UIO_USERSPACE) {
 657                 td = uio->uio_td;
 658                 KASSERT(td != NULL && td->td_proc != NULL,
 659                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 660         }
 661
 662         nsegs = 0;
 663         error = 0;
 664         first = 1;
 665         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 666                 /*
 667                  * Now at the first iovec to load.  Load each iovec
 668                  * until we have exhausted the residual count.
 669                  */
 670                 bus_size_t minlen =
 671                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 672                 caddr_t addr = (caddr_t) iov[i].iov_base;
 673
 674                 error = _bus_dmamap_load_buffer(dmat,
 675                                 dm_segments,
 676                                 addr, minlen,
 677                                 td, flags, &lastaddr, &nsegs, first);
 678                 first = 0;
 679
 680                 resid -= minlen;
 681         }
 682
 683         if (error) {
 684                 /* force "no valid mappings" in callback */
 685                 (*callback)(callback_arg, dm_segments, 0, 0, error);
 686         } else {
 687                 (*callback)(callback_arg, dm_segments,
 688                             nsegs+1, uio->uio_resid, error);
 689         }
 690         return (error);
 691 }
 692
 693 /*
 694  * Release the mapping held by map.
 695  */
 696 void
 697 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 698 {
 699         struct bounce_page *bpage;
 700
 701         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 702                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 703                 free_bounce_page(dmat, bpage);
 704         }
 705 }
 706
 707 void
 708 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 709 {
 710         struct bounce_page *bpage;
 711
 712         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 713
 714                 /*
 715                  * Handle data bouncing.  We might also
 716                  * want to add support for invalidating
 717                  * the caches on broken hardware
 718                  */
 719                 switch (op) {
 720                 case BUS_DMASYNC_PREWRITE:
 721                         while (bpage != NULL) {
 722                                 bcopy((void *)bpage->datavaddr,
 723                                       (void *)bpage->vaddr,
 724                                       bpage->datacount);
 725                                 bpage = STAILQ_NEXT(bpage, links);
 726                         }
 727                         break;
 728
 729                 case BUS_DMASYNC_POSTREAD:
 730                         while (bpage != NULL) {
 731                                 bcopy((void *)bpage->vaddr,
 732                                       (void *)bpage->datavaddr,
 733                                       bpage->datacount);
 734                                 bpage = STAILQ_NEXT(bpage, links);
 735                         }
 736                         break;
 737                 case BUS_DMASYNC_PREREAD:
 738                 case BUS_DMASYNC_POSTWRITE:
 739                         /* No-ops */
 740                         break;
 741                 }
 742         }
 743 }
 744
 745 static int
 746 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 747 {
 748         int count;
 749
 750         count = 0;
 751         if (total_bpages == 0) {
 752                 STAILQ_INIT(&bounce_page_list);
 753                 STAILQ_INIT(&bounce_map_waitinglist);
 754                 STAILQ_INIT(&bounce_map_callbacklist);
 755         }
 756
 757         while (numpages > 0) {
 758                 struct bounce_page *bpage;
 759                 int s;
 760
 761                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
 762                                                      M_NOWAIT);
 763
 764                 if (bpage == NULL)
 765                         break;
 766                 bzero(bpage, sizeof(*bpage));
 767                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 768                                                          M_NOWAIT, 0ul,
 769                                                          dmat->lowaddr,
 770                                                          PAGE_SIZE,
 771                                                          0);
 772                 if (bpage->vaddr == NULL) {
 773                         free(bpage, M_DEVBUF);
 774                         break;
 775                 }
 776                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 777                 s = splhigh();
 778                 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
 779                 total_bpages++;
 780                 free_bpages++;
 781                 splx(s);
 782                 count++;
 783                 numpages--;
 784         }
 785         return (count);
 786 }
 787
 788 static int
 789 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
 790 {
 791         int pages;
 792
 793         pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
 794         free_bpages -= pages;
 795         reserved_bpages += pages;
 796         map->pagesreserved += pages;
 797         pages = map->pagesneeded - map->pagesreserved;
 798
 799         return (pages);
 800 }
 801
 802 static vm_offset_t
 803 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 804                 bus_size_t size)
 805 {
 806         int s;
 807         struct bounce_page *bpage;
 808
 809         if (map->pagesneeded == 0)
 810                 panic("add_bounce_page: map doesn't need any pages");
 811         map->pagesneeded--;
 812
 813         if (map->pagesreserved == 0)
 814                 panic("add_bounce_page: map doesn't need any pages");
 815         map->pagesreserved--;
 816
 817         s = splhigh();
 818         bpage = STAILQ_FIRST(&bounce_page_list);
 819         if (bpage == NULL)
 820                 panic("add_bounce_page: free page list is empty");
 821
 822         STAILQ_REMOVE_HEAD(&bounce_page_list, links);
 823         reserved_bpages--;
 824         active_bpages++;
 825         splx(s);
 826
 827         bpage->datavaddr = vaddr;
 828         bpage->datacount = size;
 829         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
 830         return (bpage->busaddr);
 831 }
 832
 833 static void
 834 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 835 {
 836         int s;
 837         struct bus_dmamap *map;
 838
 839         bpage->datavaddr = 0;
 840         bpage->datacount = 0;
 841
 842         s = splhigh();
 843         STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
 844         free_bpages++;
 845         active_bpages--;
 846         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
 847                 if (reserve_bounce_pages(map->dmat, map) == 0) {
 848                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
 849                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
 850                                            map, links);
 851                         busdma_swi_pending = 1;
 852                         setsoftvm();
 853                 }
 854         }
 855         splx(s);
 856 }
 857
 858 void
 859 busdma_swi()
 860 {
 861         int s;
 862         struct bus_dmamap *map;
 863
 864         s = splhigh();
 865         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
 866                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
 867                 splx(s);
 868                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
 869                                 map->callback, map->callback_arg, /*flags*/0);
 870                 s = splhigh();
 871         }
 872         splx(s);
 873 }