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