sys/i386/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/i386/i386/Attic/busdma_machdep.c,v 1.6 2004/01/14 05:30:57 dillon 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 bus_addr_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_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 148         newtag->highaddr = trunc_page((vm_paddr_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) &&
 182             (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) &&
 333             dmat->lowaddr >= ptoa(Maxmem)) {
 334                 *vaddr = malloc(dmat->maxsize, M_DEVBUF,
 335                                 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK);
 336         } else {
 337                 /*
 338                  * XXX Use Contigmalloc until it is merged into this facility
 339                  *     and handles multi-seg allocations.  Nobody is doing
 340                  *     multi-seg allocations yet though.
 341                  */
 342                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF,
 343                     (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK,
 344                     0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
 345                     dmat->boundary);
 346         }
 347         if (*vaddr == NULL)
 348                 return (ENOMEM);
 349         return (0);
 350 }
 351
 352 /*
 353  * Free a piece of memory and it's allociated dmamap, that was allocated
 354  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 355  */
 356 void
 357 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 358 {
 359         /*
 360          * dmamem does not need to be bounced, so the map should be
 361          * NULL
 362          */
 363         if (map != NULL)
 364                 panic("bus_dmamem_free: Invalid map freed\n");
 365         if ((dmat->maxsize <= PAGE_SIZE) &&
 366             dmat->lowaddr >= ptoa(Maxmem))
 367                 free(vaddr, M_DEVBUF);
 368         else
 369                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 370 }
 371
 372 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
 373
 374 /*
 375  * Map the buffer buf into bus space using the dmamap map.
 376  */
 377 int
 378 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 379                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 380                 void *callback_arg, int flags)
 381 {
 382         vm_offset_t             vaddr;
 383         vm_paddr_t              paddr;
 384 #ifdef __GNUC__
 385         bus_dma_segment_t       dm_segments[dmat->nsegments];
 386 #else
 387         bus_dma_segment_t       dm_segments[BUS_DMAMAP_NSEGS];
 388 #endif
 389         bus_dma_segment_t      *sg;
 390         int                     seg;
 391         int                     error;
 392         vm_paddr_t              nextpaddr;
 393
 394         if (map == NULL)
 395                 map = &nobounce_dmamap;
 396
 397         error = 0;
 398         /*
 399          * If we are being called during a callback, pagesneeded will
 400          * be non-zero, so we can avoid doing the work twice.
 401          */
 402         if (dmat->lowaddr < ptoa(Maxmem) &&
 403             map->pagesneeded == 0) {
 404                 vm_offset_t     vendaddr;
 405
 406                 /*
 407                  * Count the number of bounce pages
 408                  * needed in order to complete this transfer
 409                  */
 410                 vaddr = trunc_page((vm_offset_t)buf);
 411                 vendaddr = (vm_offset_t)buf + buflen;
 412
 413                 while (vaddr < vendaddr) {
 414                         paddr = pmap_kextract(vaddr);
 415                         if (run_filter(dmat, paddr) != 0) {
 416
 417                                 map->pagesneeded++;
 418                         }
 419                         vaddr += PAGE_SIZE;
 420                 }
 421         }
 422
 423         /* Reserve Necessary Bounce Pages */
 424         if (map->pagesneeded != 0) {
 425                 int s;
 426
 427                 s = splhigh();
 428                 if (reserve_bounce_pages(dmat, map) != 0) {
 429
 430                         /* Queue us for resources */
 431                         map->dmat = dmat;
 432                         map->buf = buf;
 433                         map->buflen = buflen;
 434                         map->callback = callback;
 435                         map->callback_arg = callback_arg;
 436
 437                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 438                         splx(s);
 439
 440                         return (EINPROGRESS);
 441                 }
 442                 splx(s);
 443         }
 444
 445         vaddr = (vm_offset_t)buf;
 446         sg = &dm_segments[0];
 447         seg = 1;
 448         sg->ds_len = 0;
 449
 450         nextpaddr = 0;
 451         do {
 452                 bus_size_t      size;
 453
 454                 paddr = pmap_kextract(vaddr);
 455                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 456                 if (size > buflen)
 457                         size = buflen;
 458
 459                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 460                         paddr = add_bounce_page(dmat, map, vaddr, size);
 461                 }
 462
 463                 if (sg->ds_len == 0) {
 464                         sg->ds_addr = paddr;
 465                         sg->ds_len = size;
 466                 } else if (paddr == nextpaddr) {
 467                         sg->ds_len += size;
 468                 } else {
 469                         /* Go to the next segment */
 470                         sg++;
 471                         seg++;
 472                         if (seg > dmat->nsegments)
 473                                 break;
 474                         sg->ds_addr = paddr;
 475                         sg->ds_len = size;
 476                 }
 477                 vaddr += size;
 478                 nextpaddr = paddr + size;
 479                 buflen -= size;
 480
 481         } while (buflen > 0);
 482
 483         if (buflen != 0) {
 484                 printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
 485                        (u_long)buflen);
 486                 error = EFBIG;
 487         }
 488
 489         (*callback)(callback_arg, dm_segments, seg, error);
 490
 491         return (0);
 492 }
 493
 494 /*
 495  * Utility function to load a linear buffer.  lastaddrp holds state
 496  * between invocations (for multiple-buffer loads).  segp contains
 497  * the starting segment on entrace, and the ending segment on exit.
 498  * first indicates if this is the first invocation of this function.
 499  */
 500 static int
 501 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 502                         bus_dma_segment_t segs[],
 503                         void *buf, bus_size_t buflen,
 504                         struct thread *td,
 505                         int flags,
 506                         vm_offset_t *lastaddrp,
 507                         int *segp,
 508                         int first)
 509 {
 510         bus_size_t sgsize;
 511         bus_addr_t curaddr, lastaddr, baddr, bmask;
 512         vm_offset_t vaddr = (vm_offset_t)buf;
 513         int seg;
 514         pmap_t pmap;
 515
 516         if (td->td_proc != NULL)
 517                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 518         else
 519                 pmap = NULL;
 520
 521         lastaddr = *lastaddrp;
 522         bmask  = ~(dmat->boundary - 1);
 523
 524         for (seg = *segp; buflen > 0 ; ) {
 525                 /*
 526                  * Get the physical address for this segment.
 527                  */
 528                 if (pmap)
 529                         curaddr = pmap_extract(pmap, vaddr);
 530                 else
 531                         curaddr = pmap_kextract(vaddr);
 532
 533                 /*
 534                  * Compute the segment size, and adjust counts.
 535                  */
 536                 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
 537                 if (buflen < sgsize)
 538                         sgsize = buflen;
 539
 540                 /*
 541                  * Make sure we don't cross any boundaries.
 542                  */
 543                 if (dmat->boundary > 0) {
 544                         baddr = (curaddr + dmat->boundary) & bmask;
 545                         if (sgsize > (baddr - curaddr))
 546                                 sgsize = (baddr - curaddr);
 547                 }
 548
 549                 /*
 550                  * Insert chunk into a segment, coalescing with
 551                  * previous segment if possible.
 552                  */
 553                 if (first) {
 554                         segs[seg].ds_addr = curaddr;
 555                         segs[seg].ds_len = sgsize;
 556                         first = 0;
 557                 } else {
 558                         if (curaddr == lastaddr &&
 559                             (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
 560                             (dmat->boundary == 0 ||
 561                              (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 562                                 segs[seg].ds_len += sgsize;
 563                         else {
 564                                 if (++seg >= dmat->nsegments)
 565                                         break;
 566                                 segs[seg].ds_addr = curaddr;
 567                                 segs[seg].ds_len = sgsize;
 568                         }
 569                 }
 570
 571                 lastaddr = curaddr + sgsize;
 572                 vaddr += sgsize;
 573                 buflen -= sgsize;
 574         }
 575
 576         *segp = seg;
 577         *lastaddrp = lastaddr;
 578
 579         /*
 580          * Did we fit?
 581          */
 582         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 583 }
 584
 585 /*
 586  * Like _bus_dmamap_load(), but for mbufs.
 587  */
 588 int
 589 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 590                      struct mbuf *m0,
 591                      bus_dmamap_callback2_t *callback, void *callback_arg,
 592                      int flags)
 593 {
 594 #ifdef __GNUC__
 595         bus_dma_segment_t dm_segments[dmat->nsegments];
 596 #else
 597         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
 598 #endif
 599         int nsegs, error;
 600
 601         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 602                 ("bus_dmamap_load_mbuf: No support for bounce pages!"));
 603         KASSERT(m0->m_flags & M_PKTHDR,
 604                 ("bus_dmamap_load_mbuf: no packet header"));
 605
 606         nsegs = 0;
 607         error = 0;
 608         if (m0->m_pkthdr.len <= dmat->maxsize) {
 609                 int first = 1;
 610                 vm_offset_t lastaddr = 0;
 611                 struct mbuf *m;
 612
 613                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 614                         error = _bus_dmamap_load_buffer(dmat,
 615                                         dm_segments,
 616                                         m->m_data, m->m_len,
 617                                         curthread, flags, &lastaddr,
 618                                         &nsegs, first);
 619                         first = 0;
 620                 }
 621         } else {
 622                 error = EINVAL;
 623         }
 624
 625         if (error) {
 626                 /* force "no valid mappings" in callback */
 627                 (*callback)(callback_arg, dm_segments, 0, 0, error);
 628         } else {
 629                 (*callback)(callback_arg, dm_segments,
 630                             nsegs+1, m0->m_pkthdr.len, error);
 631         }
 632         return (error);
 633 }
 634
 635 /*
 636  * Like _bus_dmamap_load(), but for uios.
 637  */
 638 int
 639 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 640                     struct uio *uio,
 641                     bus_dmamap_callback2_t *callback, void *callback_arg,
 642                     int flags)
 643 {
 644         vm_offset_t lastaddr;
 645 #ifdef __GNUC__
 646         bus_dma_segment_t dm_segments[dmat->nsegments];
 647 #else
 648         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
 649 #endif
 650         int nsegs, error, first, i;
 651         bus_size_t resid;
 652         struct iovec *iov;
 653         struct thread *td = NULL;
 654
 655         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 656                 ("bus_dmamap_load_uio: No support for bounce pages!"));
 657
 658         resid = uio->uio_resid;
 659         iov = uio->uio_iov;
 660
 661         if (uio->uio_segflg == UIO_USERSPACE) {
 662                 td = uio->uio_td;
 663                 KASSERT(td != NULL && td->td_proc != NULL,
 664                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 665         }
 666
 667         nsegs = 0;
 668         error = 0;
 669         first = 1;
 670         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 671                 /*
 672                  * Now at the first iovec to load.  Load each iovec
 673                  * until we have exhausted the residual count.
 674                  */
 675                 bus_size_t minlen =
 676                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 677                 caddr_t addr = (caddr_t) iov[i].iov_base;
 678
 679                 error = _bus_dmamap_load_buffer(dmat,
 680                                 dm_segments,
 681                                 addr, minlen,
 682                                 td, flags, &lastaddr, &nsegs, first);
 683                 first = 0;
 684
 685                 resid -= minlen;
 686         }
 687
 688         if (error) {
 689                 /* force "no valid mappings" in callback */
 690                 (*callback)(callback_arg, dm_segments, 0, 0, error);
 691         } else {
 692                 (*callback)(callback_arg, dm_segments,
 693                             nsegs+1, uio->uio_resid, error);
 694         }
 695         return (error);
 696 }
 697
 698 /*
 699  * Release the mapping held by map.
 700  */
 701 void
 702 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 703 {
 704         struct bounce_page *bpage;
 705
 706         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 707                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 708                 free_bounce_page(dmat, bpage);
 709         }
 710 }
 711
 712 void
 713 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 714 {
 715         struct bounce_page *bpage;
 716
 717         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 718
 719                 /*
 720                  * Handle data bouncing.  We might also
 721                  * want to add support for invalidating
 722                  * the caches on broken hardware
 723                  */
 724                 switch (op) {
 725                 case BUS_DMASYNC_PREWRITE:
 726                         while (bpage != NULL) {
 727                                 bcopy((void *)bpage->datavaddr,
 728                                       (void *)bpage->vaddr,
 729                                       bpage->datacount);
 730                                 bpage = STAILQ_NEXT(bpage, links);
 731                         }
 732                         break;
 733
 734                 case BUS_DMASYNC_POSTREAD:
 735                         while (bpage != NULL) {
 736                                 bcopy((void *)bpage->vaddr,
 737                                       (void *)bpage->datavaddr,
 738                                       bpage->datacount);
 739                                 bpage = STAILQ_NEXT(bpage, links);
 740                         }
 741                         break;
 742                 case BUS_DMASYNC_PREREAD:
 743                 case BUS_DMASYNC_POSTWRITE:
 744                         /* No-ops */
 745                         break;
 746                 }
 747         }
 748 }
 749
 750 static int
 751 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 752 {
 753         int count;
 754
 755         count = 0;
 756         if (total_bpages == 0) {
 757                 STAILQ_INIT(&bounce_page_list);
 758                 STAILQ_INIT(&bounce_map_waitinglist);
 759                 STAILQ_INIT(&bounce_map_callbacklist);
 760         }
 761
 762         while (numpages > 0) {
 763                 struct bounce_page *bpage;
 764                 int s;
 765
 766                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
 767                                                      M_NOWAIT);
 768
 769                 if (bpage == NULL)
 770                         break;
 771                 bzero(bpage, sizeof(*bpage));
 772                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 773                                                          M_NOWAIT, 0ul,
 774                                                          dmat->lowaddr,
 775                                                          PAGE_SIZE,
 776                                                          0);
 777                 if (bpage->vaddr == NULL) {
 778                         free(bpage, M_DEVBUF);
 779                         break;
 780                 }
 781                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 782                 s = splhigh();
 783                 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
 784                 total_bpages++;
 785                 free_bpages++;
 786                 splx(s);
 787                 count++;
 788                 numpages--;
 789         }
 790         return (count);
 791 }
 792
 793 static int
 794 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
 795 {
 796         int pages;
 797
 798         pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
 799         free_bpages -= pages;
 800         reserved_bpages += pages;
 801         map->pagesreserved += pages;
 802         pages = map->pagesneeded - map->pagesreserved;
 803
 804         return (pages);
 805 }
 806
 807 static bus_addr_t
 808 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 809                 bus_size_t size)
 810 {
 811         int s;
 812         struct bounce_page *bpage;
 813
 814         if (map->pagesneeded == 0)
 815                 panic("add_bounce_page: map doesn't need any pages");
 816         map->pagesneeded--;
 817
 818         if (map->pagesreserved == 0)
 819                 panic("add_bounce_page: map doesn't need any pages");
 820         map->pagesreserved--;
 821
 822         s = splhigh();
 823         bpage = STAILQ_FIRST(&bounce_page_list);
 824         if (bpage == NULL)
 825                 panic("add_bounce_page: free page list is empty");
 826
 827         STAILQ_REMOVE_HEAD(&bounce_page_list, links);
 828         reserved_bpages--;
 829         active_bpages++;
 830         splx(s);
 831
 832         bpage->datavaddr = vaddr;
 833         bpage->datacount = size;
 834         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
 835         return (bpage->busaddr);
 836 }
 837
 838 static void
 839 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 840 {
 841         int s;
 842         struct bus_dmamap *map;
 843
 844         bpage->datavaddr = 0;
 845         bpage->datacount = 0;
 846
 847         s = splhigh();
 848         STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
 849         free_bpages++;
 850         active_bpages--;
 851         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
 852                 if (reserve_bounce_pages(map->dmat, map) == 0) {
 853                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
 854                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
 855                                            map, links);
 856                         busdma_swi_pending = 1;
 857                         setsoftvm();
 858                 }
 859         }
 860         splx(s);
 861 }
 862
 863 void
 864 busdma_swi()
 865 {
 866         int s;
 867         struct bus_dmamap *map;
 868
 869         s = splhigh();
 870         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
 871                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
 872                 splx(s);
 873                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
 874                                 map->callback, map->callback_arg, /*flags*/0);
 875                 s = splhigh();
 876         }
 877         splx(s);
 878 }