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 1.9 2004/04/19 13:37:43 joerg 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         bus_dma_segment_t *segments;
  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 bus_addr_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_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 149         newtag->highaddr = trunc_page((vm_paddr_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         newtag->segments = malloc(sizeof(bus_dma_segment_t) * newtag->nsegments,
 159                                   M_DEVBUF, M_INTWAIT);
 160         if (newtag->segments == NULL) {
 161                 free(newtag, M_DEVBUF);
 162                 return(ENOMEM);
 163         }
 164
 165         /* Take into account any restrictions imposed by our parent tag */
 166         if (parent != NULL) {
 167                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 168                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 169                 /*
 170                  * XXX Not really correct??? Probably need to honor boundary
 171                  *     all the way up the inheritence chain.
 172                  */
 173                 newtag->boundary = MAX(parent->boundary, newtag->boundary);
 174                 if (newtag->filter == NULL) {
 175                         /*
 176                          * Short circuit looking at our parent directly
 177                          * since we have encapsulated all of its information
 178                          */
 179                         newtag->filter = parent->filter;
 180                         newtag->filterarg = parent->filterarg;
 181                         newtag->parent = parent->parent;
 182                 }
 183                 if (newtag->parent != NULL) {
 184                         parent->ref_count++;
 185                 }
 186         }
 187
 188         if (newtag->lowaddr < ptoa(Maxmem) &&
 189             (flags & BUS_DMA_ALLOCNOW) != 0) {
 190                 /* Must bounce */
 191
 192                 if (lowaddr > bounce_lowaddr) {
 193                         /*
 194                          * Go through the pool and kill any pages
 195                          * that don't reside below lowaddr.
 196                          */
 197                         panic("bus_dma_tag_create: page reallocation "
 198                               "not implemented");
 199                 }
 200                 if (ptoa(total_bpages) < maxsize) {
 201                         int pages;
 202
 203                         pages = atop(maxsize) - total_bpages;
 204
 205                         /* Add pages to our bounce pool */
 206                         if (alloc_bounce_pages(newtag, pages) < pages)
 207                                 error = ENOMEM;
 208                 }
 209                 /* Performed initial allocation */
 210                 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 211         }
 212
 213         if (error != 0) {
 214                 free(newtag, M_DEVBUF);
 215         } else {
 216                 *dmat = newtag;
 217         }
 218         return (error);
 219 }
 220
 221 int
 222 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 223 {
 224         if (dmat != NULL) {
 225
 226                 if (dmat->map_count != 0)
 227                         return (EBUSY);
 228
 229                 while (dmat != NULL) {
 230                         bus_dma_tag_t parent;
 231
 232                         parent = dmat->parent;
 233                         dmat->ref_count--;
 234                         if (dmat->ref_count == 0) {
 235                                 if (dmat->segments != NULL)
 236                                         free(dmat->segments, M_DEVBUF);
 237                                 free(dmat, M_DEVBUF);
 238                                 /*
 239                                  * Last reference count, so
 240                                  * release our reference
 241                                  * count on our parent.
 242                                  */
 243                                 dmat = parent;
 244                         } else
 245                                 dmat = NULL;
 246                 }
 247         }
 248         return (0);
 249 }
 250
 251 /*
 252  * Allocate a handle for mapping from kva/uva/physical
 253  * address space into bus device space.
 254  */
 255 int
 256 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 257 {
 258         int error;
 259
 260         error = 0;
 261
 262         if (dmat->lowaddr < ptoa(Maxmem)) {
 263                 /* Must bounce */
 264                 int maxpages;
 265
 266                 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 267                                              M_NOWAIT);
 268                 if (*mapp == NULL) {
 269                         return (ENOMEM);
 270                 } else {
 271                         /* Initialize the new map */
 272                         bzero(*mapp, sizeof(**mapp));
 273                         STAILQ_INIT(&((*mapp)->bpages));
 274                 }
 275                 /*
 276                  * Attempt to add pages to our pool on a per-instance
 277                  * basis up to a sane limit.
 278                  */
 279                 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
 280                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
 281                  || (dmat->map_count > 0
 282                   && total_bpages < maxpages)) {
 283                         int pages;
 284
 285                         if (dmat->lowaddr > bounce_lowaddr) {
 286                                 /*
 287                                  * Go through the pool and kill any pages
 288                                  * that don't reside below lowaddr.
 289                                  */
 290                                 panic("bus_dmamap_create: page reallocation "
 291                                       "not implemented");
 292                         }
 293                         pages = atop(dmat->maxsize);
 294                         pages = MIN(maxpages - total_bpages, pages);
 295                         error = alloc_bounce_pages(dmat, pages);
 296
 297                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 298                                 if (error == 0)
 299                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 300                         } else {
 301                                 error = 0;
 302                         }
 303                 }
 304         } else {
 305                 *mapp = NULL;
 306         }
 307         if (error == 0)
 308                 dmat->map_count++;
 309         return (error);
 310 }
 311
 312 /*
 313  * Destroy a handle for mapping from kva/uva/physical
 314  * address space into bus device space.
 315  */
 316 int
 317 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 318 {
 319         if (map != NULL) {
 320                 if (STAILQ_FIRST(&map->bpages) != NULL)
 321                         return (EBUSY);
 322                 free(map, M_DEVBUF);
 323         }
 324         dmat->map_count--;
 325         return (0);
 326 }
 327
 328
 329 /*
 330  * Allocate a piece of memory that can be efficiently mapped into
 331  * bus device space based on the constraints lited in the dma tag.
 332  * A dmamap to for use with dmamap_load is also allocated.
 333  */
 334 int
 335 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 336                  bus_dmamap_t *mapp)
 337 {
 338         int mflags;
 339         /* If we succeed, no mapping/bouncing will be required */
 340         *mapp = NULL;
 341
 342         if (flags & BUS_DMA_NOWAIT)
 343                 mflags = M_NOWAIT;
 344         else
 345                 mflags = M_WAITOK;
 346         if (flags & BUS_DMA_ZERO)
 347                 mflags |= M_ZERO;
 348
 349         if ((dmat->maxsize <= PAGE_SIZE) &&
 350             dmat->lowaddr >= ptoa(Maxmem)) {
 351                 *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
 352                 /*
 353                  * XXX Check wether the allocation crossed a page boundary
 354                  * and retry with power-of-2 alignment in that case.
 355                  */
 356                 if ((((intptr_t)*vaddr) & PAGE_MASK) !=
 357                     (((intptr_t)*vaddr + dmat->maxsize) & PAGE_MASK)) {
 358                         size_t size;
 359                         free(*vaddr, M_DEVBUF);
 360                         /* XXX check for overflow? */
 361                         for (size = 1; size <= dmat->maxsize; size <<= 1)
 362                                 ;
 363                         *vaddr = malloc(size, M_DEVBUF, mflags);
 364                 }
 365         } else {
 366                 /*
 367                  * XXX Use Contigmalloc until it is merged into this facility
 368                  *     and handles multi-seg allocations.  Nobody is doing
 369                  *     multi-seg allocations yet though.
 370                  */
 371                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 372                     0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
 373                     dmat->boundary);
 374         }
 375         if (*vaddr == NULL)
 376                 return (ENOMEM);
 377         return (0);
 378 }
 379
 380 /*
 381  * Free a piece of memory and it's allociated dmamap, that was allocated
 382  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 383  */
 384 void
 385 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 386 {
 387         /*
 388          * dmamem does not need to be bounced, so the map should be
 389          * NULL
 390          */
 391         if (map != NULL)
 392                 panic("bus_dmamem_free: Invalid map freed\n");
 393         if ((dmat->maxsize <= PAGE_SIZE) &&
 394             dmat->lowaddr >= ptoa(Maxmem))
 395                 free(vaddr, M_DEVBUF);
 396         else
 397                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 398 }
 399
 400 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
 401
 402 /*
 403  * Map the buffer buf into bus space using the dmamap map.
 404  */
 405 int
 406 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 407                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 408                 void *callback_arg, int flags)
 409 {
 410         vm_offset_t             vaddr;
 411         vm_paddr_t              paddr;
 412         bus_dma_segment_t      *sg;
 413         int                     seg;
 414         int                     error;
 415         vm_paddr_t              nextpaddr;
 416
 417         if (map == NULL)
 418                 map = &nobounce_dmamap;
 419
 420         error = 0;
 421         /*
 422          * If we are being called during a callback, pagesneeded will
 423          * be non-zero, so we can avoid doing the work twice.
 424          */
 425         if (dmat->lowaddr < ptoa(Maxmem) &&
 426             map->pagesneeded == 0) {
 427                 vm_offset_t     vendaddr;
 428
 429                 /*
 430                  * Count the number of bounce pages
 431                  * needed in order to complete this transfer
 432                  */
 433                 vaddr = trunc_page((vm_offset_t)buf);
 434                 vendaddr = (vm_offset_t)buf + buflen;
 435
 436                 while (vaddr < vendaddr) {
 437                         paddr = pmap_kextract(vaddr);
 438                         if (run_filter(dmat, paddr) != 0) {
 439
 440                                 map->pagesneeded++;
 441                         }
 442                         vaddr += PAGE_SIZE;
 443                 }
 444         }
 445
 446         /* Reserve Necessary Bounce Pages */
 447         if (map->pagesneeded != 0) {
 448                 int s;
 449
 450                 s = splhigh();
 451                 if (reserve_bounce_pages(dmat, map) != 0) {
 452
 453                         /* Queue us for resources */
 454                         map->dmat = dmat;
 455                         map->buf = buf;
 456                         map->buflen = buflen;
 457                         map->callback = callback;
 458                         map->callback_arg = callback_arg;
 459
 460                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 461                         splx(s);
 462
 463                         return (EINPROGRESS);
 464                 }
 465                 splx(s);
 466         }
 467
 468         vaddr = (vm_offset_t)buf;
 469         sg = dmat->segments;
 470         seg = 1;
 471         sg->ds_len = 0;
 472
 473         nextpaddr = 0;
 474         do {
 475                 bus_size_t      size;
 476
 477                 paddr = pmap_kextract(vaddr);
 478                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 479                 if (size > buflen)
 480                         size = buflen;
 481
 482                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 483                         paddr = add_bounce_page(dmat, map, vaddr, size);
 484                 }
 485
 486                 if (sg->ds_len == 0) {
 487                         sg->ds_addr = paddr;
 488                         sg->ds_len = size;
 489                 } else if (paddr == nextpaddr) {
 490                         sg->ds_len += size;
 491                 } else {
 492                         /* Go to the next segment */
 493                         sg++;
 494                         seg++;
 495                         if (seg > dmat->nsegments)
 496                                 break;
 497                         sg->ds_addr = paddr;
 498                         sg->ds_len = size;
 499                 }
 500                 vaddr += size;
 501                 nextpaddr = paddr + size;
 502                 buflen -= size;
 503         } while (buflen > 0);
 504
 505         if (buflen != 0) {
 506                 printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
 507                        (u_long)buflen);
 508                 error = EFBIG;
 509         }
 510
 511         (*callback)(callback_arg, dmat->segments, seg, error);
 512
 513         return (0);
 514 }
 515
 516 /*
 517  * Utility function to load a linear buffer.  lastaddrp holds state
 518  * between invocations (for multiple-buffer loads).  segp contains
 519  * the starting segment on entrace, and the ending segment on exit.
 520  * first indicates if this is the first invocation of this function.
 521  */
 522 static int
 523 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 524                         void *buf, bus_size_t buflen,
 525                         struct thread *td,
 526                         int flags,
 527                         vm_offset_t *lastaddrp,
 528                         int *segp,
 529                         int first)
 530 {
 531         bus_dma_segment_t *segs;
 532         bus_size_t sgsize;
 533         bus_addr_t curaddr, lastaddr, baddr, bmask;
 534         vm_offset_t vaddr = (vm_offset_t)buf;
 535         int seg;
 536         pmap_t pmap;
 537
 538         if (td->td_proc != NULL)
 539                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 540         else
 541                 pmap = NULL;
 542
 543         segs = dmat->segments;
 544         lastaddr = *lastaddrp;
 545         bmask  = ~(dmat->boundary - 1);
 546
 547         for (seg = *segp; buflen > 0 ; ) {
 548                 /*
 549                  * Get the physical address for this segment.
 550                  */
 551                 if (pmap)
 552                         curaddr = pmap_extract(pmap, vaddr);
 553                 else
 554                         curaddr = pmap_kextract(vaddr);
 555
 556                 /*
 557                  * Compute the segment size, and adjust counts.
 558                  */
 559                 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
 560                 if (buflen < sgsize)
 561                         sgsize = buflen;
 562
 563                 /*
 564                  * Make sure we don't cross any boundaries.
 565                  */
 566                 if (dmat->boundary > 0) {
 567                         baddr = (curaddr + dmat->boundary) & bmask;
 568                         if (sgsize > (baddr - curaddr))
 569                                 sgsize = (baddr - curaddr);
 570                 }
 571
 572                 /*
 573                  * Insert chunk into a segment, coalescing with
 574                  * previous segment if possible.
 575                  */
 576                 if (first) {
 577                         segs[seg].ds_addr = curaddr;
 578                         segs[seg].ds_len = sgsize;
 579                         first = 0;
 580                 } else {
 581                         if (curaddr == lastaddr &&
 582                             (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
 583                             (dmat->boundary == 0 ||
 584                              (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 585                                 segs[seg].ds_len += sgsize;
 586                         else {
 587                                 if (++seg >= dmat->nsegments)
 588                                         break;
 589                                 segs[seg].ds_addr = curaddr;
 590                                 segs[seg].ds_len = sgsize;
 591                         }
 592                 }
 593
 594                 lastaddr = curaddr + sgsize;
 595                 vaddr += sgsize;
 596                 buflen -= sgsize;
 597         }
 598
 599         *segp = seg;
 600         *lastaddrp = lastaddr;
 601
 602         /*
 603          * Did we fit?
 604          */
 605         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 606 }
 607
 608 /*
 609  * Like _bus_dmamap_load(), but for mbufs.
 610  */
 611 int
 612 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 613                      struct mbuf *m0,
 614                      bus_dmamap_callback2_t *callback, void *callback_arg,
 615                      int flags)
 616 {
 617         int nsegs, error;
 618
 619         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 620                 ("bus_dmamap_load_mbuf: No support for bounce pages!"));
 621         KASSERT(m0->m_flags & M_PKTHDR,
 622                 ("bus_dmamap_load_mbuf: no packet header"));
 623
 624         nsegs = 0;
 625         error = 0;
 626         if (m0->m_pkthdr.len <= dmat->maxsize) {
 627                 int first = 1;
 628                 vm_offset_t lastaddr = 0;
 629                 struct mbuf *m;
 630
 631                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 632                         error = _bus_dmamap_load_buffer(dmat,
 633                                         m->m_data, m->m_len,
 634                                         curthread, flags, &lastaddr,
 635                                         &nsegs, first);
 636                         first = 0;
 637                 }
 638         } else {
 639                 error = EINVAL;
 640         }
 641
 642         if (error) {
 643                 /* force "no valid mappings" in callback */
 644                 (*callback)(callback_arg, dmat->segments, 0, 0, error);
 645         } else {
 646                 (*callback)(callback_arg, dmat->segments,
 647                             nsegs+1, m0->m_pkthdr.len, error);
 648         }
 649         return (error);
 650 }
 651
 652 /*
 653  * Like _bus_dmamap_load(), but for uios.
 654  */
 655 int
 656 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 657                     struct uio *uio,
 658                     bus_dmamap_callback2_t *callback, void *callback_arg,
 659                     int flags)
 660 {
 661         vm_offset_t lastaddr;
 662         int nsegs, error, first, i;
 663         bus_size_t resid;
 664         struct iovec *iov;
 665         struct thread *td = NULL;
 666
 667         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 668                 ("bus_dmamap_load_uio: No support for bounce pages!"));
 669
 670         resid = uio->uio_resid;
 671         iov = uio->uio_iov;
 672
 673         if (uio->uio_segflg == UIO_USERSPACE) {
 674                 td = uio->uio_td;
 675                 KASSERT(td != NULL && td->td_proc != NULL,
 676                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 677         }
 678
 679         nsegs = 0;
 680         error = 0;
 681         first = 1;
 682         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 683                 /*
 684                  * Now at the first iovec to load.  Load each iovec
 685                  * until we have exhausted the residual count.
 686                  */
 687                 bus_size_t minlen =
 688                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 689                 caddr_t addr = (caddr_t) iov[i].iov_base;
 690
 691                 error = _bus_dmamap_load_buffer(dmat,
 692                                 addr, minlen,
 693                                 td, flags, &lastaddr, &nsegs, first);
 694                 first = 0;
 695
 696                 resid -= minlen;
 697         }
 698
 699         if (error) {
 700                 /* force "no valid mappings" in callback */
 701                 (*callback)(callback_arg, dmat->segments, 0, 0, error);
 702         } else {
 703                 (*callback)(callback_arg, dmat->segments,
 704                             nsegs+1, uio->uio_resid, error);
 705         }
 706         return (error);
 707 }
 708
 709 /*
 710  * Release the mapping held by map.
 711  */
 712 void
 713 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 714 {
 715         struct bounce_page *bpage;
 716
 717         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 718                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 719                 free_bounce_page(dmat, bpage);
 720         }
 721 }
 722
 723 void
 724 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 725 {
 726         struct bounce_page *bpage;
 727
 728         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 729
 730                 /*
 731                  * Handle data bouncing.  We might also
 732                  * want to add support for invalidating
 733                  * the caches on broken hardware
 734                  */
 735                 switch (op) {
 736                 case BUS_DMASYNC_PREWRITE:
 737                         while (bpage != NULL) {
 738                                 bcopy((void *)bpage->datavaddr,
 739                                       (void *)bpage->vaddr,
 740                                       bpage->datacount);
 741                                 bpage = STAILQ_NEXT(bpage, links);
 742                         }
 743                         break;
 744
 745                 case BUS_DMASYNC_POSTREAD:
 746                         while (bpage != NULL) {
 747                                 bcopy((void *)bpage->vaddr,
 748                                       (void *)bpage->datavaddr,
 749                                       bpage->datacount);
 750                                 bpage = STAILQ_NEXT(bpage, links);
 751                         }
 752                         break;
 753                 case BUS_DMASYNC_PREREAD:
 754                 case BUS_DMASYNC_POSTWRITE:
 755                         /* No-ops */
 756                         break;
 757                 }
 758         }
 759 }
 760
 761 static int
 762 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 763 {
 764         int count;
 765
 766         count = 0;
 767         if (total_bpages == 0) {
 768                 STAILQ_INIT(&bounce_page_list);
 769                 STAILQ_INIT(&bounce_map_waitinglist);
 770                 STAILQ_INIT(&bounce_map_callbacklist);
 771         }
 772
 773         while (numpages > 0) {
 774                 struct bounce_page *bpage;
 775                 int s;
 776
 777                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
 778                                                      M_NOWAIT);
 779
 780                 if (bpage == NULL)
 781                         break;
 782                 bzero(bpage, sizeof(*bpage));
 783                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 784                                                          M_NOWAIT, 0ul,
 785                                                          dmat->lowaddr,
 786                                                          PAGE_SIZE,
 787                                                          0);
 788                 if (bpage->vaddr == NULL) {
 789                         free(bpage, M_DEVBUF);
 790                         break;
 791                 }
 792                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 793                 s = splhigh();
 794                 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
 795                 total_bpages++;
 796                 free_bpages++;
 797                 splx(s);
 798                 count++;
 799                 numpages--;
 800         }
 801         return (count);
 802 }
 803
 804 static int
 805 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
 806 {
 807         int pages;
 808
 809         pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
 810         free_bpages -= pages;
 811         reserved_bpages += pages;
 812         map->pagesreserved += pages;
 813         pages = map->pagesneeded - map->pagesreserved;
 814
 815         return (pages);
 816 }
 817
 818 static bus_addr_t
 819 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 820                 bus_size_t size)
 821 {
 822         int s;
 823         struct bounce_page *bpage;
 824
 825         if (map->pagesneeded == 0)
 826                 panic("add_bounce_page: map doesn't need any pages");
 827         map->pagesneeded--;
 828
 829         if (map->pagesreserved == 0)
 830                 panic("add_bounce_page: map doesn't need any pages");
 831         map->pagesreserved--;
 832
 833         s = splhigh();
 834         bpage = STAILQ_FIRST(&bounce_page_list);
 835         if (bpage == NULL)
 836                 panic("add_bounce_page: free page list is empty");
 837
 838         STAILQ_REMOVE_HEAD(&bounce_page_list, links);
 839         reserved_bpages--;
 840         active_bpages++;
 841         splx(s);
 842
 843         bpage->datavaddr = vaddr;
 844         bpage->datacount = size;
 845         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
 846         return (bpage->busaddr);
 847 }
 848
 849 static void
 850 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 851 {
 852         int s;
 853         struct bus_dmamap *map;
 854
 855         bpage->datavaddr = 0;
 856         bpage->datacount = 0;
 857
 858         s = splhigh();
 859         STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
 860         free_bpages++;
 861         active_bpages--;
 862         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
 863                 if (reserve_bounce_pages(map->dmat, map) == 0) {
 864                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
 865                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
 866                                            map, links);
 867                         busdma_swi_pending = 1;
 868                         setsoftvm();
 869                 }
 870         }
 871         splx(s);
 872 }
 873
 874 void
 875 busdma_swi()
 876 {
 877         int s;
 878         struct bus_dmamap *map;
 879
 880         s = splhigh();
 881         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
 882                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
 883                 splx(s);
 884                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
 885                                 map->callback, map->callback_arg, /*flags*/0);
 886                 s = splhigh();
 887         }
 888         splx(s);
 889 }