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 1.3 2003/06/25 03:55:53 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(a,b) (((a) > (b)) ? (a) : (b))
  48 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
  49 #define MAX_BPAGES 128
  50
  51 struct bus_dma_tag {
  52         bus_dma_tag_t     parent;
  53         bus_size_t        alignment;
  54         bus_size_t        boundary;
  55         bus_addr_t        lowaddr;
  56         bus_addr_t        highaddr;
  57         bus_dma_filter_t *filter;
  58         void             *filterarg;
  59         bus_size_t        maxsize;
  60         u_int             nsegments;
  61         bus_size_t        maxsegsz;
  62         int               flags;
  63         int               ref_count;
  64         int               map_count;
  65 };
  66
  67 struct bounce_page {
  68         vm_offset_t     vaddr;          /* kva of bounce buffer */
  69         bus_addr_t      busaddr;        /* Physical address */
  70         vm_offset_t     datavaddr;      /* kva of client data */
  71         bus_size_t      datacount;      /* client data count */
  72         STAILQ_ENTRY(bounce_page) links;
  73 };
  74
  75 int busdma_swi_pending;
  76
  77 static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  78 static int free_bpages;
  79 static int reserved_bpages;
  80 static int active_bpages;
  81 static int total_bpages;
  82 static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
  83
  84 struct bus_dmamap {
  85         struct bp_list         bpages;
  86         int                    pagesneeded;
  87         int                    pagesreserved;
  88         bus_dma_tag_t          dmat;
  89         void                  *buf;             /* unmapped buffer pointer */
  90         bus_size_t             buflen;          /* unmapped buffer length */
  91         bus_dmamap_callback_t *callback;
  92         void                  *callback_arg;
  93         STAILQ_ENTRY(bus_dmamap) links;
  94 };
  95
  96 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
  97 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
  98 static struct bus_dmamap nobounce_dmamap;
  99
 100 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 101 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map);
 102 static vm_offset_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 103                                    vm_offset_t vaddr, bus_size_t size);
 104 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 105 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 106
 107 static __inline int
 108 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 109 {
 110         int retval;
 111
 112         retval = 0;
 113         do {
 114                 if (paddr > dmat->lowaddr
 115                  && paddr <= dmat->highaddr
 116                  && (dmat->filter == NULL
 117                   || (*dmat->filter)(dmat->filterarg, paddr) != 0))
 118                         retval = 1;
 119
 120                 dmat = dmat->parent;
 121         } while (retval == 0 && dmat != NULL);
 122         return (retval);
 123 }
 124
 125 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
 126 /*
 127  * Allocate a device specific dma_tag.
 128  */
 129 int
 130 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 131                    bus_size_t boundary, bus_addr_t lowaddr,
 132                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 133                    void *filterarg, bus_size_t maxsize, int nsegments,
 134                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 135 {
 136         bus_dma_tag_t newtag;
 137         int error = 0;
 138
 139         /* Return a NULL tag on failure */
 140         *dmat = NULL;
 141
 142         newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
 143         if (newtag == NULL)
 144                 return (ENOMEM);
 145
 146         newtag->parent = parent;
 147         newtag->alignment = alignment;
 148         newtag->boundary = boundary;
 149         newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
 150         newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
 151         newtag->filter = filter;
 152         newtag->filterarg = filterarg;
 153         newtag->maxsize = maxsize;
 154         newtag->nsegments = nsegments;
 155         newtag->maxsegsz = maxsegsz;
 156         newtag->flags = flags;
 157         newtag->ref_count = 1; /* Count ourself */
 158         newtag->map_count = 0;
 159
 160         /* Take into account any restrictions imposed by our parent tag */
 161         if (parent != NULL) {
 162                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 163                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 164                 /*
 165                  * XXX Not really correct??? Probably need to honor boundary
 166                  *     all the way up the inheritence chain.
 167                  */
 168                 newtag->boundary = MAX(parent->boundary, newtag->boundary);
 169                 if (newtag->filter == NULL) {
 170                         /*
 171                          * Short circuit looking at our parent directly
 172                          * since we have encapsulated all of its information
 173                          */
 174                         newtag->filter = parent->filter;
 175                         newtag->filterarg = parent->filterarg;
 176                         newtag->parent = parent->parent;
 177                 }
 178                 if (newtag->parent != NULL) {
 179                         parent->ref_count++;
 180                 }
 181         }
 182
 183         if (newtag->lowaddr < ptoa(Maxmem) && (flags & BUS_DMA_ALLOCNOW) != 0) {
 184                 /* Must bounce */
 185
 186                 if (lowaddr > bounce_lowaddr) {
 187                         /*
 188                          * Go through the pool and kill any pages
 189                          * that don't reside below lowaddr.
 190                          */
 191                         panic("bus_dma_tag_create: page reallocation "
 192                               "not implemented");
 193                 }
 194                 if (ptoa(total_bpages) < maxsize) {
 195                         int pages;
 196
 197                         pages = atop(maxsize) - total_bpages;
 198
 199                         /* Add pages to our bounce pool */
 200                         if (alloc_bounce_pages(newtag, pages) < pages)
 201                                 error = ENOMEM;
 202                 }
 203                 /* Performed initial allocation */
 204                 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 205         }
 206
 207         if (error != 0) {
 208                 free(newtag, M_DEVBUF);
 209         } else {
 210                 *dmat = newtag;
 211         }
 212         return (error);
 213 }
 214
 215 int
 216 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 217 {
 218         if (dmat != NULL) {
 219
 220                 if (dmat->map_count != 0)
 221                         return (EBUSY);
 222
 223                 while (dmat != NULL) {
 224                         bus_dma_tag_t parent;
 225
 226                         parent = dmat->parent;
 227                         dmat->ref_count--;
 228                         if (dmat->ref_count == 0) {
 229                                 free(dmat, M_DEVBUF);
 230                                 /*
 231                                  * Last reference count, so
 232                                  * release our reference
 233                                  * count on our parent.
 234                                  */
 235                                 dmat = parent;
 236                         } else
 237                                 dmat = NULL;
 238                 }
 239         }
 240         return (0);
 241 }
 242
 243 /*
 244  * Allocate a handle for mapping from kva/uva/physical
 245  * address space into bus device space.
 246  */
 247 int
 248 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 249 {
 250         int error;
 251
 252         error = 0;
 253
 254         if (dmat->lowaddr < ptoa(Maxmem)) {
 255                 /* Must bounce */
 256                 int maxpages;
 257
 258                 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 259                                              M_NOWAIT);
 260                 if (*mapp == NULL) {
 261                         return (ENOMEM);
 262                 } else {
 263                         /* Initialize the new map */
 264                         bzero(*mapp, sizeof(**mapp));
 265                         STAILQ_INIT(&((*mapp)->bpages));
 266                 }
 267                 /*
 268                  * Attempt to add pages to our pool on a per-instance
 269                  * basis up to a sane limit.
 270                  */
 271                 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
 272                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
 273                  || (dmat->map_count > 0
 274                   && total_bpages < maxpages)) {
 275                         int pages;
 276
 277                         if (dmat->lowaddr > bounce_lowaddr) {
 278                                 /*
 279                                  * Go through the pool and kill any pages
 280                                  * that don't reside below lowaddr.
 281                                  */
 282                                 panic("bus_dmamap_create: page reallocation "
 283                                       "not implemented");
 284                         }
 285                         pages = atop(dmat->maxsize);
 286                         pages = MIN(maxpages - total_bpages, pages);
 287                         error = alloc_bounce_pages(dmat, pages);
 288
 289                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 290                                 if (error == 0)
 291                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 292                         } else {
 293                                 error = 0;
 294                         }
 295                 }
 296         } else {
 297                 *mapp = NULL;
 298         }
 299         if (error == 0)
 300                 dmat->map_count++;
 301         return (error);
 302 }
 303
 304 /*
 305  * Destroy a handle for mapping from kva/uva/physical
 306  * address space into bus device space.
 307  */
 308 int
 309 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 310 {
 311         if (map != NULL) {
 312                 if (STAILQ_FIRST(&map->bpages) != NULL)
 313                         return (EBUSY);
 314                 free(map, M_DEVBUF);
 315         }
 316         dmat->map_count--;
 317         return (0);
 318 }
 319
 320
 321 /*
 322  * Allocate a piece of memory that can be efficiently mapped into
 323  * bus device space based on the constraints lited in the dma tag.
 324  * A dmamap to for use with dmamap_load is also allocated.
 325  */
 326 int
 327 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 328                  bus_dmamap_t *mapp)
 329 {
 330         /* If we succeed, no mapping/bouncing will be required */
 331         *mapp = NULL;
 332
 333         if ((dmat->maxsize <= PAGE_SIZE) && 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) && dmat->lowaddr >= ptoa(Maxmem))
 366                 free(vaddr, M_DEVBUF);
 367         else
 368                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 369 }
 370
 371 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
 372
 373 /*
 374  * Map the buffer buf into bus space using the dmamap map.
 375  */
 376 int
 377 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 378                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 379                 void *callback_arg, int flags)
 380 {
 381         vm_offset_t             vaddr;
 382         vm_offset_t             paddr;
 383 #ifdef __GNUC__
 384         bus_dma_segment_t       dm_segments[dmat->nsegments];
 385 #else
 386         bus_dma_segment_t       dm_segments[BUS_DMAMAP_NSEGS];
 387 #endif
 388         bus_dma_segment_t      *sg;
 389         int                     seg;
 390         int                     error;
 391         vm_offset_t             nextpaddr;
 392
 393         if (map == NULL)
 394                 map = &nobounce_dmamap;
 395
 396         error = 0;
 397         /*
 398          * If we are being called during a callback, pagesneeded will
 399          * be non-zero, so we can avoid doing the work twice.
 400          */
 401         if (dmat->lowaddr < ptoa(Maxmem) && map->pagesneeded == 0) {
 402                 vm_offset_t     vendaddr;
 403
 404                 /*
 405                  * Count the number of bounce pages
 406                  * needed in order to complete this transfer
 407                  */
 408                 vaddr = trunc_page((vm_offset_t)buf);
 409                 vendaddr = (vm_offset_t)buf + buflen;
 410
 411                 while (vaddr < vendaddr) {
 412                         paddr = pmap_kextract(vaddr);
 413                         if (run_filter(dmat, paddr) != 0) {
 414
 415                                 map->pagesneeded++;
 416                         }
 417                         vaddr += PAGE_SIZE;
 418                 }
 419         }
 420
 421         /* Reserve Necessary Bounce Pages */
 422         if (map->pagesneeded != 0) {
 423                 int s;
 424
 425                 s = splhigh();
 426                 if (reserve_bounce_pages(dmat, map) != 0) {
 427
 428                         /* Queue us for resources */
 429                         map->dmat = dmat;
 430                         map->buf = buf;
 431                         map->buflen = buflen;
 432                         map->callback = callback;
 433                         map->callback_arg = callback_arg;
 434
 435                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 436                         splx(s);
 437
 438                         return (EINPROGRESS);
 439                 }
 440                 splx(s);
 441         }
 442
 443         vaddr = (vm_offset_t)buf;
 444         sg = &dm_segments[0];
 445         seg = 1;
 446         sg->ds_len = 0;
 447
 448         nextpaddr = 0;
 449         do {
 450                 bus_size_t      size;
 451
 452                 paddr = pmap_kextract(vaddr);
 453                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 454                 if (size > buflen)
 455                         size = buflen;
 456
 457                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 458                         paddr = add_bounce_page(dmat, map, vaddr, size);
 459                 }
 460
 461                 if (sg->ds_len == 0) {
 462                         sg->ds_addr = paddr;
 463                         sg->ds_len = size;
 464                 } else if (paddr == nextpaddr) {
 465                         sg->ds_len += size;
 466                 } else {
 467                         /* Go to the next segment */
 468                         sg++;
 469                         seg++;
 470                         if (seg > dmat->nsegments)
 471                                 break;
 472                         sg->ds_addr = paddr;
 473                         sg->ds_len = size;
 474                 }
 475                 vaddr += size;
 476                 nextpaddr = paddr + size;
 477                 buflen -= size;
 478
 479         } while (buflen > 0);
 480
 481         if (buflen != 0) {
 482                 printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
 483                        (u_long)buflen);
 484                 error = EFBIG;
 485         }
 486
 487         (*callback)(callback_arg, dm_segments, seg, error);
 488
 489         return (0);
 490 }
 491
 492 /*
 493  * Utility function to load a linear buffer.  lastaddrp holds state
 494  * between invocations (for multiple-buffer loads).  segp contains
 495  * the starting segment on entrace, and the ending segment on exit.
 496  * first indicates if this is the first invocation of this function.
 497  */
 498 static int
 499 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 500                         bus_dma_segment_t segs[],
 501                         void *buf, bus_size_t buflen,
 502                         struct thread *td,
 503                         int flags,
 504                         vm_offset_t *lastaddrp,
 505                         int *segp,
 506                         int first)
 507 {
 508         bus_size_t sgsize;
 509         bus_addr_t curaddr, lastaddr, baddr, bmask;
 510         vm_offset_t vaddr = (vm_offset_t)buf;
 511         int seg;
 512         pmap_t pmap;
 513
 514         if (td->td_proc != NULL)
 515                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 516         else
 517                 pmap = NULL;
 518
 519         lastaddr = *lastaddrp;
 520         bmask  = ~(dmat->boundary - 1);
 521
 522         for (seg = *segp; buflen > 0 ; ) {
 523                 /*
 524                  * Get the physical address for this segment.
 525                  */
 526                 if (pmap)
 527                         curaddr = pmap_extract(pmap, vaddr);
 528                 else
 529                         curaddr = pmap_kextract(vaddr);
 530
 531                 /*
 532                  * Compute the segment size, and adjust counts.
 533                  */
 534                 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
 535                 if (buflen < sgsize)
 536                         sgsize = buflen;
 537
 538                 /*
 539                  * Make sure we don't cross any boundaries.
 540                  */
 541                 if (dmat->boundary > 0) {
 542                         baddr = (curaddr + dmat->boundary) & bmask;
 543                         if (sgsize > (baddr - curaddr))
 544                                 sgsize = (baddr - curaddr);
 545                 }
 546
 547                 /*
 548                  * Insert chunk into a segment, coalescing with
 549                  * previous segment if possible.
 550                  */
 551                 if (first) {
 552                         segs[seg].ds_addr = curaddr;
 553                         segs[seg].ds_len = sgsize;
 554                         first = 0;
 555                 } else {
 556                         if (curaddr == lastaddr &&
 557                             (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
 558                             (dmat->boundary == 0 ||
 559                              (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 560                                 segs[seg].ds_len += sgsize;
 561                         else {
 562                                 if (++seg >= dmat->nsegments)
 563                                         break;
 564                                 segs[seg].ds_addr = curaddr;
 565                                 segs[seg].ds_len = sgsize;
 566                         }
 567                 }
 568
 569                 lastaddr = curaddr + sgsize;
 570                 vaddr += sgsize;
 571                 buflen -= sgsize;
 572         }
 573
 574         *segp = seg;
 575         *lastaddrp = lastaddr;
 576
 577         /*
 578          * Did we fit?
 579          */
 580         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 581 }
 582
 583 /*
 584  * Like _bus_dmamap_load(), but for mbufs.
 585  */
 586 int
 587 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 588                      struct mbuf *m0,
 589                      bus_dmamap_callback2_t *callback, void *callback_arg,
 590                      int flags)
 591 {
 592 #ifdef __GNUC__
 593         bus_dma_segment_t dm_segments[dmat->nsegments];
 594 #else
 595         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
 596 #endif
 597         int nsegs, error;
 598
 599         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 600                 ("bus_dmamap_load_mbuf: No support for bounce pages!"));
 601         KASSERT(m0->m_flags & M_PKTHDR,
 602                 ("bus_dmamap_load_mbuf: no packet header"));
 603
 604         nsegs = 0;
 605         error = 0;
 606         if (m0->m_pkthdr.len <= dmat->maxsize) {
 607                 int first = 1;
 608                 vm_offset_t lastaddr = 0;
 609                 struct mbuf *m;
 610
 611                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 612                         error = _bus_dmamap_load_buffer(dmat,
 613                                         dm_segments,
 614                                         m->m_data, m->m_len,
 615                                         NULL, flags, &lastaddr, &nsegs, first);
 616                         first = 0;
 617                 }
 618         } else {
 619                 error = EINVAL;
 620         }
 621
 622         if (error) {
 623                 /* force "no valid mappings" in callback */
 624                 (*callback)(callback_arg, dm_segments, 0, 0, error);
 625         } else {
 626                 (*callback)(callback_arg, dm_segments,
 627                             nsegs+1, m0->m_pkthdr.len, error);
 628         }
 629         return (error);
 630 }
 631
 632 /*
 633  * Like _bus_dmamap_load(), but for uios.
 634  */
 635 int
 636 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 637                     struct uio *uio,
 638                     bus_dmamap_callback2_t *callback, void *callback_arg,
 639                     int flags)
 640 {
 641         vm_offset_t lastaddr;
 642 #ifdef __GNUC__
 643         bus_dma_segment_t dm_segments[dmat->nsegments];
 644 #else
 645         bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
 646 #endif
 647         int nsegs, error, first, i;
 648         bus_size_t resid;
 649         struct iovec *iov;
 650         struct thread *td = NULL;
 651
 652         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 653                 ("bus_dmamap_load_uio: No support for bounce pages!"));
 654
 655         resid = uio->uio_resid;
 656         iov = uio->uio_iov;
 657
 658         if (uio->uio_segflg == UIO_USERSPACE) {
 659                 td = uio->uio_td;
 660                 KASSERT(td != NULL && td->td_proc != NULL,
 661                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 662         }
 663
 664         nsegs = 0;
 665         error = 0;
 666         first = 1;
 667         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 668                 /*
 669                  * Now at the first iovec to load.  Load each iovec
 670                  * until we have exhausted the residual count.
 671                  */
 672                 bus_size_t minlen =
 673                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 674                 caddr_t addr = (caddr_t) iov[i].iov_base;
 675
 676                 error = _bus_dmamap_load_buffer(dmat,
 677                                 dm_segments,
 678                                 addr, minlen,
 679                                 td, flags, &lastaddr, &nsegs, first);
 680                 first = 0;
 681
 682                 resid -= minlen;
 683         }
 684
 685         if (error) {
 686                 /* force "no valid mappings" in callback */
 687                 (*callback)(callback_arg, dm_segments, 0, 0, error);
 688         } else {
 689                 (*callback)(callback_arg, dm_segments,
 690                             nsegs+1, uio->uio_resid, error);
 691         }
 692         return (error);
 693 }
 694
 695 /*
 696  * Release the mapping held by map.
 697  */
 698 void
 699 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 700 {
 701         struct bounce_page *bpage;
 702
 703         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 704                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 705                 free_bounce_page(dmat, bpage);
 706         }
 707 }
 708
 709 void
 710 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 711 {
 712         struct bounce_page *bpage;
 713
 714         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 715
 716                 /*
 717                  * Handle data bouncing.  We might also
 718                  * want to add support for invalidating
 719                  * the caches on broken hardware
 720                  */
 721                 switch (op) {
 722                 case BUS_DMASYNC_PREWRITE:
 723                         while (bpage != NULL) {
 724                                 bcopy((void *)bpage->datavaddr,
 725                                       (void *)bpage->vaddr,
 726                                       bpage->datacount);
 727                                 bpage = STAILQ_NEXT(bpage, links);
 728                         }
 729                         break;
 730
 731                 case BUS_DMASYNC_POSTREAD:
 732                         while (bpage != NULL) {
 733                                 bcopy((void *)bpage->vaddr,
 734                                       (void *)bpage->datavaddr,
 735                                       bpage->datacount);
 736                                 bpage = STAILQ_NEXT(bpage, links);
 737                         }
 738                         break;
 739                 case BUS_DMASYNC_PREREAD:
 740                 case BUS_DMASYNC_POSTWRITE:
 741                         /* No-ops */
 742                         break;
 743                 }
 744         }
 745 }
 746
 747 static int
 748 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 749 {
 750         int count;
 751
 752         count = 0;
 753         if (total_bpages == 0) {
 754                 STAILQ_INIT(&bounce_page_list);
 755                 STAILQ_INIT(&bounce_map_waitinglist);
 756                 STAILQ_INIT(&bounce_map_callbacklist);
 757         }
 758
 759         while (numpages > 0) {
 760                 struct bounce_page *bpage;
 761                 int s;
 762
 763                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
 764                                                      M_NOWAIT);
 765
 766                 if (bpage == NULL)
 767                         break;
 768                 bzero(bpage, sizeof(*bpage));
 769                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 770                                                          M_NOWAIT, 0ul,
 771                                                          dmat->lowaddr,
 772                                                          PAGE_SIZE,
 773                                                          0);
 774                 if (bpage->vaddr == NULL) {
 775                         free(bpage, M_DEVBUF);
 776                         break;
 777                 }
 778                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 779                 s = splhigh();
 780                 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
 781                 total_bpages++;
 782                 free_bpages++;
 783                 splx(s);
 784                 count++;
 785                 numpages--;
 786         }
 787         return (count);
 788 }
 789
 790 static int
 791 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
 792 {
 793         int pages;
 794
 795         pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
 796         free_bpages -= pages;
 797         reserved_bpages += pages;
 798         map->pagesreserved += pages;
 799         pages = map->pagesneeded - map->pagesreserved;
 800
 801         return (pages);
 802 }
 803
 804 static vm_offset_t
 805 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 806                 bus_size_t size)
 807 {
 808         int s;
 809         struct bounce_page *bpage;
 810
 811         if (map->pagesneeded == 0)
 812                 panic("add_bounce_page: map doesn't need any pages");
 813         map->pagesneeded--;
 814
 815         if (map->pagesreserved == 0)
 816                 panic("add_bounce_page: map doesn't need any pages");
 817         map->pagesreserved--;
 818
 819         s = splhigh();
 820         bpage = STAILQ_FIRST(&bounce_page_list);
 821         if (bpage == NULL)
 822                 panic("add_bounce_page: free page list is empty");
 823
 824         STAILQ_REMOVE_HEAD(&bounce_page_list, links);
 825         reserved_bpages--;
 826         active_bpages++;
 827         splx(s);
 828
 829         bpage->datavaddr = vaddr;
 830         bpage->datacount = size;
 831         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
 832         return (bpage->busaddr);
 833 }
 834
 835 static void
 836 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 837 {
 838         int s;
 839         struct bus_dmamap *map;
 840
 841         bpage->datavaddr = 0;
 842         bpage->datacount = 0;
 843
 844         s = splhigh();
 845         STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
 846         free_bpages++;
 847         active_bpages--;
 848         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
 849                 if (reserve_bounce_pages(map->dmat, map) == 0) {
 850                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
 851                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
 852                                            map, links);
 853                         busdma_swi_pending = 1;
 854                         setsoftvm();
 855                 }
 856         }
 857         splx(s);
 858 }
 859
 860 void
 861 busdma_swi()
 862 {
 863         int s;
 864         struct bus_dmamap *map;
 865
 866         s = splhigh();
 867         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
 868                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
 869                 splx(s);
 870                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
 871                                 map->callback, map->callback_arg, /*flags*/0);
 872                 s = splhigh();
 873         }
 874         splx(s);
 875 }