sys/platform/pc32/i386/busdma_machdep.c

   1 /*
   2  * Copyright (c) 1997, 1998 Justin T. Gibbs.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions, and the following disclaimer,
  10  *    without modification, immediately at the beginning of the file.
  11  * 2. The name of the author may not be used to endorse or promote products
  12  *    derived from this software without specific prior written permission.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  18  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/sys/i386/i386/busdma_machdep.c,v 1.16.2.2 2003/01/23 00:55:27 scottl Exp $
  27  * $DragonFly: src/sys/platform/pc32/i386/busdma_machdep.c,v 1.23 2008/06/05 18:06:32 swildner 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 #include <sys/thread2.h>
  36 #include <sys/bus_dma.h>
  37 #include <sys/kernel.h>
  38 #include <sys/sysctl.h>
  39
  40 #include <vm/vm.h>
  41 #include <vm/vm_page.h>
  42
  43 /* XXX needed for to access pmap to convert per-proc virtual to physical */
  44 #include <sys/proc.h>
  45 #include <sys/lock.h>
  46 #include <vm/vm_map.h>
  47
  48 #include <machine/md_var.h>
  49
  50 #define MAX_BPAGES      1024
  51
  52 struct bounce_zone;
  53 struct bus_dmamap;
  54
  55 struct bus_dma_tag {
  56         bus_dma_tag_t   parent;
  57         bus_size_t      alignment;
  58         bus_size_t      boundary;
  59         bus_addr_t      lowaddr;
  60         bus_addr_t      highaddr;
  61         bus_dma_filter_t *filter;
  62         void            *filterarg;
  63         bus_size_t      maxsize;
  64         u_int           nsegments;
  65         bus_size_t      maxsegsz;
  66         int             flags;
  67         int             ref_count;
  68         int             map_count;
  69         bus_dma_segment_t *segments;
  70         struct bounce_zone *bounce_zone;
  71 };
  72
  73 /*
  74  * bus_dma_tag private flags
  75  */
  76 #define BUS_DMA_COULD_BOUNCE    BUS_DMA_BUS3
  77 #define BUS_DMA_MIN_ALLOC_COMP  BUS_DMA_BUS4
  78
  79 struct bounce_page {
  80         vm_offset_t     vaddr;          /* kva of bounce buffer */
  81         bus_addr_t      busaddr;        /* Physical address */
  82         vm_offset_t     datavaddr;      /* kva of client data */
  83         bus_size_t      datacount;      /* client data count */
  84         STAILQ_ENTRY(bounce_page) links;
  85 };
  86
  87 struct bounce_zone {
  88         STAILQ_ENTRY(bounce_zone) links;
  89         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  90         STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
  91         int             total_bpages;
  92         int             free_bpages;
  93         int             reserved_bpages;
  94         int             active_bpages;
  95         int             total_bounced;
  96         int             total_deferred;
  97         int             reserve_failed;
  98         bus_size_t      alignment;
  99         bus_size_t      boundary;
 100         bus_addr_t      lowaddr;
 101         char            zoneid[8];
 102         char            lowaddrid[20];
 103         struct sysctl_ctx_list sysctl_ctx;
 104         struct sysctl_oid *sysctl_tree;
 105 };
 106
 107 static struct lwkt_token bounce_zone_tok =
 108         LWKT_TOKEN_INITIALIZER(bounce_zone_tok);
 109 static int busdma_zonecount;
 110 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
 111         STAILQ_HEAD_INITIALIZER(bounce_zone_list);
 112
 113 int busdma_swi_pending;
 114 static int total_bounce_pages;
 115 static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
 116
 117 struct bus_dmamap {
 118         struct bp_list  bpages;
 119         int             pagesneeded;
 120         int             pagesreserved;
 121         bus_dma_tag_t   dmat;
 122         void            *buf;           /* unmapped buffer pointer */
 123         bus_size_t      buflen;         /* unmapped buffer length */
 124         bus_dmamap_callback_t *callback;
 125         void            *callback_arg;
 126         STAILQ_ENTRY(bus_dmamap) links;
 127 };
 128
 129 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
 130         STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
 131
 132 static struct bus_dmamap nobounce_dmamap;
 133
 134 static int              alloc_bounce_zone(bus_dma_tag_t);
 135 static int              alloc_bounce_pages(bus_dma_tag_t, u_int);
 136 static int              reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
 137 static bus_addr_t       add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
 138                             vm_offset_t, bus_size_t);
 139 static void             free_bounce_page(bus_dma_tag_t, struct bounce_page *);
 140
 141 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 142 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
 143            0, "Total bounce pages");
 144
 145 static __inline int
 146 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 147 {
 148         int retval;
 149
 150         retval = 0;
 151         do {
 152                 if (paddr > dmat->lowaddr
 153                  && paddr <= dmat->highaddr
 154                  && (dmat->filter == NULL
 155                   || (*dmat->filter)(dmat->filterarg, paddr) != 0))
 156                         retval = 1;
 157
 158                 dmat = dmat->parent;
 159         } while (retval == 0 && dmat != NULL);
 160         return (retval);
 161 }
 162
 163 /*
 164  * Allocate a device specific dma_tag.
 165  */
 166 int
 167 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 168                    bus_size_t boundary, bus_addr_t lowaddr,
 169                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 170                    void *filterarg, bus_size_t maxsize, int nsegments,
 171                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 172 {
 173         bus_dma_tag_t newtag;
 174         int error = 0;
 175
 176         if (alignment == 0)
 177                 alignment = 1;
 178
 179         /* Return a NULL tag on failure */
 180         *dmat = NULL;
 181
 182         newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
 183
 184         newtag->parent = parent;
 185         newtag->alignment = alignment;
 186         newtag->boundary = boundary;
 187         newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 188         newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
 189         newtag->filter = filter;
 190         newtag->filterarg = filterarg;
 191         newtag->maxsize = maxsize;
 192         newtag->nsegments = nsegments;
 193         newtag->maxsegsz = maxsegsz;
 194         newtag->flags = flags;
 195         newtag->ref_count = 1; /* Count ourself */
 196         newtag->map_count = 0;
 197         newtag->segments = NULL;
 198         newtag->bounce_zone = NULL;
 199
 200         /* Take into account any restrictions imposed by our parent tag */
 201         if (parent != NULL) {
 202                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 203                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 204
 205                 if (newtag->boundary == 0) {
 206                         newtag->boundary = parent->boundary;
 207                 } else if (parent->boundary != 0) {
 208                         newtag->boundary = MIN(parent->boundary,
 209                                                newtag->boundary);
 210                 }
 211
 212 #ifdef notyet
 213                 newtag->alignment = MAX(parent->alignment, newtag->alignment);
 214 #endif
 215
 216                 if (newtag->filter == NULL) {
 217                         /*
 218                          * Short circuit looking at our parent directly
 219                          * since we have encapsulated all of its information
 220                          */
 221                         newtag->filter = parent->filter;
 222                         newtag->filterarg = parent->filterarg;
 223                         newtag->parent = parent->parent;
 224                 }
 225                 if (newtag->parent != NULL)
 226                         parent->ref_count++;
 227         }
 228
 229         if (newtag->lowaddr < ptoa(Maxmem))
 230                 newtag->flags |= BUS_DMA_COULD_BOUNCE;
 231
 232         if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
 233             (flags & BUS_DMA_ALLOCNOW) != 0) {
 234                 struct bounce_zone *bz;
 235
 236                 /* Must bounce */
 237
 238                 if (lowaddr > bounce_lowaddr) {
 239                         /*
 240                          * Go through the pool and kill any pages
 241                          * that don't reside below lowaddr.
 242                          */
 243                         panic("bus_dma_tag_create: page reallocation "
 244                               "not implemented");
 245                 }
 246
 247                 error = alloc_bounce_zone(newtag);
 248                 if (error)
 249                         goto back;
 250                 bz = newtag->bounce_zone;
 251
 252                 if (ptoa(bz->total_bpages) < maxsize) {
 253                         int pages;
 254
 255                         pages = atop(maxsize) - bz->total_bpages;
 256
 257                         /* Add pages to our bounce pool */
 258                         if (alloc_bounce_pages(newtag, pages) < pages)
 259                                 error = ENOMEM;
 260                 }
 261                 /* Performed initial allocation */
 262                 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 263         }
 264 back:
 265         if (error)
 266                 kfree(newtag, M_DEVBUF);
 267         else
 268                 *dmat = newtag;
 269         return error;
 270 }
 271
 272 int
 273 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 274 {
 275         if (dmat != NULL) {
 276                 if (dmat->map_count != 0)
 277                         return (EBUSY);
 278
 279                 while (dmat != NULL) {
 280                         bus_dma_tag_t parent;
 281
 282                         parent = dmat->parent;
 283                         dmat->ref_count--;
 284                         if (dmat->ref_count == 0) {
 285                                 if (dmat->segments != NULL)
 286                                         kfree(dmat->segments, M_DEVBUF);
 287                                 kfree(dmat, M_DEVBUF);
 288                                 /*
 289                                  * Last reference count, so
 290                                  * release our reference
 291                                  * count on our parent.
 292                                  */
 293                                 dmat = parent;
 294                         } else
 295                                 dmat = NULL;
 296                 }
 297         }
 298         return (0);
 299 }
 300
 301 /*
 302  * Allocate a handle for mapping from kva/uva/physical
 303  * address space into bus device space.
 304  */
 305 int
 306 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 307 {
 308         int error;
 309
 310         error = 0;
 311
 312         if (dmat->segments == NULL) {
 313                 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
 314                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 315                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 316         }
 317
 318         if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
 319                 struct bounce_zone *bz;
 320                 int maxpages;
 321
 322                 /* Must bounce */
 323
 324                 if (dmat->bounce_zone == NULL) {
 325                         error = alloc_bounce_zone(dmat);
 326                         if (error)
 327                                 return error;
 328                 }
 329                 bz = dmat->bounce_zone;
 330
 331                 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
 332
 333                 /* Initialize the new map */
 334                 STAILQ_INIT(&((*mapp)->bpages));
 335                 /*
 336                  * Attempt to add pages to our pool on a per-instance
 337                  * basis up to a sane limit.
 338                  */
 339                 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
 340                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
 341                  || (dmat->map_count > 0
 342                   && bz->total_bpages < maxpages)) {
 343                         int pages;
 344
 345                         if (dmat->lowaddr > bounce_lowaddr) {
 346                                 /*
 347                                  * Go through the pool and kill any pages
 348                                  * that don't reside below lowaddr.
 349                                  */
 350                                 panic("bus_dmamap_create: page reallocation "
 351                                       "not implemented");
 352                         }
 353
 354                         pages = MAX(atop(dmat->maxsize), 1);
 355                         pages = MIN(maxpages - bz->total_bpages, pages);
 356                         pages = MAX(pages, 1);
 357                         if (alloc_bounce_pages(dmat, pages) < pages)
 358                                 error = ENOMEM;
 359
 360                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 361                                 if (!error)
 362                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 363                         } else {
 364                                 error = 0;
 365                         }
 366                 }
 367         } else {
 368                 *mapp = NULL;
 369         }
 370         if (!error)
 371                 dmat->map_count++;
 372         return error;
 373 }
 374
 375 /*
 376  * Destroy a handle for mapping from kva/uva/physical
 377  * address space into bus device space.
 378  */
 379 int
 380 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 381 {
 382         if (map != NULL) {
 383                 if (STAILQ_FIRST(&map->bpages) != NULL)
 384                         return (EBUSY);
 385                 kfree(map, M_DEVBUF);
 386         }
 387         dmat->map_count--;
 388         return (0);
 389 }
 390
 391 /*
 392  * Allocate a piece of memory that can be efficiently mapped into
 393  * bus device space based on the constraints lited in the dma tag.
 394  *
 395  * mapp is degenerate.  By definition this allocation should not require
 396  * bounce buffers so do not allocate a dma map.
 397  */
 398 int
 399 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 400                  bus_dmamap_t *mapp)
 401 {
 402         int mflags;
 403
 404         /* If we succeed, no mapping/bouncing will be required */
 405         *mapp = NULL;
 406
 407         if (dmat->segments == NULL) {
 408                 KKASSERT(dmat->nsegments < 16384);
 409                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 410                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 411         }
 412
 413         if (flags & BUS_DMA_NOWAIT)
 414                 mflags = M_NOWAIT;
 415         else
 416                 mflags = M_WAITOK;
 417         if (flags & BUS_DMA_ZERO)
 418                 mflags |= M_ZERO;
 419
 420         if ((dmat->maxsize <= PAGE_SIZE) &&
 421             dmat->lowaddr >= ptoa(Maxmem)) {
 422                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 423                 /*
 424                  * XXX Check whether the allocation crossed a page boundary
 425                  * and retry with power-of-2 alignment in that case.
 426                  */
 427                 if ((((intptr_t)*vaddr) & PAGE_MASK) !=
 428                     (((intptr_t)*vaddr + dmat->maxsize) & PAGE_MASK)) {
 429                         size_t size;
 430
 431                         kfree(*vaddr, M_DEVBUF);
 432                         /* XXX check for overflow? */
 433                         for (size = 1; size <= dmat->maxsize; size <<= 1)
 434                                 ;
 435                         *vaddr = kmalloc(size, M_DEVBUF, mflags);
 436                 }
 437         } else {
 438                 /*
 439                  * XXX Use Contigmalloc until it is merged into this facility
 440                  *     and handles multi-seg allocations.  Nobody is doing
 441                  *     multi-seg allocations yet though.
 442                  */
 443                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 444                     0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
 445         }
 446         if (*vaddr == NULL)
 447                 return (ENOMEM);
 448         return (0);
 449 }
 450
 451 /*
 452  * Free a piece of memory and it's allociated dmamap, that was allocated
 453  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 454  */
 455 void
 456 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 457 {
 458         /*
 459          * dmamem does not need to be bounced, so the map should be
 460          * NULL
 461          */
 462         if (map != NULL)
 463                 panic("bus_dmamem_free: Invalid map freed\n");
 464         if ((dmat->maxsize <= PAGE_SIZE) &&
 465             dmat->lowaddr >= ptoa(Maxmem))
 466                 kfree(vaddr, M_DEVBUF);
 467         else
 468                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 469 }
 470
 471 static __inline vm_paddr_t
 472 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
 473 {
 474         if (pmap)
 475                 return pmap_extract(pmap, vaddr);
 476         else
 477                 return pmap_kextract(vaddr);
 478 }
 479
 480 /*
 481  * Utility function to load a linear buffer.  lastaddrp holds state
 482  * between invocations (for multiple-buffer loads).  segp contains
 483  * the segment following the starting one on entrace, and the ending
 484  * segment on exit.  first indicates if this is the first invocation
 485  * of this function.
 486  */
 487 static int
 488 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 489                         bus_dmamap_t map,
 490                         void *buf, bus_size_t buflen,
 491                         pmap_t pmap,
 492                         int flags,
 493                         vm_paddr_t *lastpaddrp,
 494                         int *segp,
 495                         int first)
 496 {
 497         vm_offset_t vaddr;
 498         vm_paddr_t paddr, nextpaddr;
 499         bus_dma_segment_t *sg;
 500         bus_addr_t bmask;
 501         int seg, error = 0;
 502
 503         if (map == NULL)
 504                 map = &nobounce_dmamap;
 505
 506         /*
 507          * If we are being called during a callback, pagesneeded will
 508          * be non-zero, so we can avoid doing the work twice.
 509          */
 510         if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 511             map != &nobounce_dmamap && map->pagesneeded == 0) {
 512                 vm_offset_t vendaddr;
 513
 514                 /*
 515                  * Count the number of bounce pages
 516                  * needed in order to complete this transfer
 517                  */
 518                 vaddr = (vm_offset_t)buf;
 519                 vendaddr = (vm_offset_t)buf + buflen;
 520
 521                 while (vaddr < vendaddr) {
 522                         paddr = _bus_dma_extract(pmap, vaddr);
 523                         if (run_filter(dmat, paddr) != 0)
 524                                 map->pagesneeded++;
 525                         vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
 526                 }
 527         }
 528
 529         /* Reserve Necessary Bounce Pages */
 530         if (map->pagesneeded != 0) {
 531                 crit_enter();
 532                 if (flags & BUS_DMA_NOWAIT) {
 533                         if (reserve_bounce_pages(dmat, map, 0) != 0) {
 534                                 crit_exit();
 535                                 return (ENOMEM);
 536                         }
 537                 } else {
 538                         if (reserve_bounce_pages(dmat, map, 1) != 0) {
 539                                 /* Queue us for resources */
 540                                 map->dmat = dmat;
 541                                 map->buf = buf;
 542                                 map->buflen = buflen;
 543
 544                                 STAILQ_INSERT_TAIL(
 545                                     &dmat->bounce_zone->bounce_map_waitinglist,
 546                                     map, links);
 547                                 crit_exit();
 548
 549                                 return (EINPROGRESS);
 550                         }
 551                 }
 552                 crit_exit();
 553         }
 554
 555         KKASSERT(*segp >= 1);
 556         seg = *segp;
 557         sg = &dmat->segments[seg - 1];
 558
 559         vaddr = (vm_offset_t)buf;
 560         nextpaddr = *lastpaddrp;
 561         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 562
 563         /* force at least one segment */
 564         do {
 565                 bus_size_t size;
 566
 567                 /*
 568                  * Per-page main loop
 569                  */
 570                 paddr = _bus_dma_extract(pmap, vaddr);
 571                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 572                 if (size > buflen)
 573                         size = buflen;
 574                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 575                         /*
 576                          * note: this paddr has the same in-page offset
 577                          * as vaddr and thus the paddr above, so the
 578                          * size does not have to be recalculated
 579                          */
 580                         paddr = add_bounce_page(dmat, map, vaddr, size);
 581                 }
 582
 583                 /*
 584                  * Fill in the bus_dma_segment
 585                  */
 586                 if (first) {
 587                         sg->ds_addr = paddr;
 588                         sg->ds_len = size;
 589                         first = 0;
 590                 } else if (paddr == nextpaddr) {
 591                         sg->ds_len += size;
 592                 } else {
 593                         sg++;
 594                         seg++;
 595                         if (seg > dmat->nsegments)
 596                                 break;
 597                         sg->ds_addr = paddr;
 598                         sg->ds_len = size;
 599                 }
 600                 nextpaddr = paddr + size;
 601
 602                 /*
 603                  * Handle maxsegsz and boundary issues with a nested loop
 604                  */
 605                 for (;;) {
 606                         bus_size_t tmpsize;
 607
 608                         /*
 609                          * Limit to the boundary and maximum segment size
 610                          */
 611                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 612                                 tmpsize = dmat->boundary -
 613                                           (sg->ds_addr & ~bmask);
 614                                 if (tmpsize > dmat->maxsegsz)
 615                                         tmpsize = dmat->maxsegsz;
 616                                 KKASSERT(tmpsize < sg->ds_len);
 617                         } else if (sg->ds_len > dmat->maxsegsz) {
 618                                 tmpsize = dmat->maxsegsz;
 619                         } else {
 620                                 break;
 621                         }
 622
 623                         /*
 624                          * Futz, split the data into a new segment.
 625                          */
 626                         if (seg >= dmat->nsegments)
 627                                 goto fail;
 628                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 629                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 630                         sg[0].ds_len = tmpsize;
 631                         sg++;
 632                         seg++;
 633                 }
 634
 635                 /*
 636                  * Adjust for loop
 637                  */
 638                 buflen -= size;
 639                 vaddr += size;
 640         } while (buflen > 0);
 641 fail:
 642         if (buflen != 0) {
 643                 kprintf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
 644                        (u_long)buflen);
 645                 error = EFBIG;
 646         }
 647
 648         *segp = seg;
 649         *lastpaddrp = nextpaddr;
 650
 651         return error;
 652 }
 653
 654 /*
 655  * Map the buffer buf into bus space using the dmamap map.
 656  */
 657 int
 658 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 659                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 660                 void *callback_arg, int flags)
 661 {
 662         vm_paddr_t lastaddr = 0;
 663         int error, nsegs = 1;
 664
 665         if (map != NULL) {
 666                 /*
 667                  * XXX
 668                  * Follow old semantics.  Once all of the callers are fixed,
 669                  * we should get rid of these internal flag "adjustment".
 670                  */
 671                 flags &= ~BUS_DMA_NOWAIT;
 672                 flags |= BUS_DMA_WAITOK;
 673
 674                 map->callback = callback;
 675                 map->callback_arg = callback_arg;
 676         }
 677
 678         error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
 679                         NULL, flags, &lastaddr, &nsegs, 1);
 680         if (error == EINPROGRESS)
 681                 return error;
 682
 683         callback(callback_arg, dmat->segments, nsegs, error);
 684         return 0;
 685 }
 686
 687 /*
 688  * Like _bus_dmamap_load(), but for mbufs.
 689  */
 690 int
 691 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 692                      struct mbuf *m0,
 693                      bus_dmamap_callback2_t *callback, void *callback_arg,
 694                      int flags)
 695 {
 696         int nsegs, error;
 697
 698         M_ASSERTPKTHDR(m0);
 699
 700         /*
 701          * XXX
 702          * Follow old semantics.  Once all of the callers are fixed,
 703          * we should get rid of these internal flag "adjustment".
 704          */
 705         flags &= ~BUS_DMA_WAITOK;
 706         flags |= BUS_DMA_NOWAIT;
 707
 708         if (m0->m_pkthdr.len <= dmat->maxsize) {
 709                 int first = 1;
 710                 vm_paddr_t lastaddr = 0;
 711                 struct mbuf *m;
 712
 713                 nsegs = 1;
 714                 error = 0;
 715                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 716                         if (m->m_len == 0)
 717                                 continue;
 718
 719                         error = _bus_dmamap_load_buffer(dmat, map,
 720                                         m->m_data, m->m_len,
 721                                         NULL, flags, &lastaddr,
 722                                         &nsegs, first);
 723                         first = 0;
 724                 }
 725         } else {
 726                 nsegs = 0;
 727                 error = EINVAL;
 728         }
 729
 730         if (error) {
 731                 /* force "no valid mappings" in callback */
 732                 callback(callback_arg, dmat->segments, 0, 0, error);
 733         } else {
 734                 callback(callback_arg, dmat->segments, nsegs,
 735                          m0->m_pkthdr.len, error);
 736         }
 737         return error;
 738 }
 739
 740 /*
 741  * Like _bus_dmamap_load(), but for uios.
 742  */
 743 int
 744 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 745                     struct uio *uio,
 746                     bus_dmamap_callback2_t *callback, void *callback_arg,
 747                     int flags)
 748 {
 749         vm_paddr_t lastaddr;
 750         int nsegs, error, first, i;
 751         bus_size_t resid;
 752         struct iovec *iov;
 753         pmap_t pmap;
 754
 755         /*
 756          * XXX
 757          * Follow old semantics.  Once all of the callers are fixed,
 758          * we should get rid of these internal flag "adjustment".
 759          */
 760         flags &= ~BUS_DMA_WAITOK;
 761         flags |= BUS_DMA_NOWAIT;
 762
 763         resid = uio->uio_resid;
 764         iov = uio->uio_iov;
 765
 766         if (uio->uio_segflg == UIO_USERSPACE) {
 767                 struct thread *td;
 768
 769                 td = uio->uio_td;
 770                 KASSERT(td != NULL && td->td_proc != NULL,
 771                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 772                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 773         } else {
 774                 pmap = NULL;
 775         }
 776
 777         error = 0;
 778         nsegs = 1;
 779         first = 1;
 780         lastaddr = 0;
 781         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 782                 /*
 783                  * Now at the first iovec to load.  Load each iovec
 784                  * until we have exhausted the residual count.
 785                  */
 786                 bus_size_t minlen =
 787                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 788                 caddr_t addr = (caddr_t) iov[i].iov_base;
 789
 790                 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
 791                                 pmap, flags, &lastaddr, &nsegs, first);
 792                 first = 0;
 793
 794                 resid -= minlen;
 795         }
 796
 797         if (error) {
 798                 /* force "no valid mappings" in callback */
 799                 callback(callback_arg, dmat->segments, 0, 0, error);
 800         } else {
 801                 callback(callback_arg, dmat->segments, nsegs,
 802                          uio->uio_resid, error);
 803         }
 804         return error;
 805 }
 806
 807 /*
 808  * Release the mapping held by map.
 809  */
 810 void
 811 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 812 {
 813         struct bounce_page *bpage;
 814
 815         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 816                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 817                 free_bounce_page(dmat, bpage);
 818         }
 819 }
 820
 821 void
 822 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 823 {
 824         struct bounce_page *bpage;
 825
 826         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 827                 /*
 828                  * Handle data bouncing.  We might also
 829                  * want to add support for invalidating
 830                  * the caches on broken hardware
 831                  */
 832                 switch (op) {
 833                 case BUS_DMASYNC_PREWRITE:
 834                         while (bpage != NULL) {
 835                                 bcopy((void *)bpage->datavaddr,
 836                                       (void *)bpage->vaddr,
 837                                       bpage->datacount);
 838                                 bpage = STAILQ_NEXT(bpage, links);
 839                         }
 840                         dmat->bounce_zone->total_bounced++;
 841                         break;
 842
 843                 case BUS_DMASYNC_POSTREAD:
 844                         while (bpage != NULL) {
 845                                 bcopy((void *)bpage->vaddr,
 846                                       (void *)bpage->datavaddr,
 847                                       bpage->datacount);
 848                                 bpage = STAILQ_NEXT(bpage, links);
 849                         }
 850                         dmat->bounce_zone->total_bounced++;
 851                         break;
 852
 853                 case BUS_DMASYNC_PREREAD:
 854                 case BUS_DMASYNC_POSTWRITE:
 855                         /* No-ops */
 856                         break;
 857                 }
 858         }
 859 }
 860
 861 static int
 862 alloc_bounce_zone(bus_dma_tag_t dmat)
 863 {
 864         struct bounce_zone *bz, *new_bz;
 865         lwkt_tokref ref;
 866
 867         KASSERT(dmat->bounce_zone == NULL,
 868                 ("bounce zone was already assigned\n"));
 869
 870         new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
 871
 872         lwkt_gettoken(&ref, &bounce_zone_tok);
 873
 874         /* Check to see if we already have a suitable zone */
 875         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
 876                 if (dmat->alignment <= bz->alignment &&
 877                     dmat->boundary <= bz->boundary &&
 878                     dmat->lowaddr >= bz->lowaddr) {
 879                         lwkt_reltoken(&ref);
 880
 881                         dmat->bounce_zone = bz;
 882                         kfree(new_bz, M_DEVBUF);
 883                         return 0;
 884                 }
 885         }
 886         bz = new_bz;
 887
 888         STAILQ_INIT(&bz->bounce_page_list);
 889         STAILQ_INIT(&bz->bounce_map_waitinglist);
 890         bz->free_bpages = 0;
 891         bz->reserved_bpages = 0;
 892         bz->active_bpages = 0;
 893         bz->lowaddr = dmat->lowaddr;
 894         bz->alignment = dmat->alignment;
 895         bz->boundary = dmat->boundary;
 896         ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
 897         busdma_zonecount++;
 898         ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
 899         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
 900
 901         lwkt_reltoken(&ref);
 902
 903         dmat->bounce_zone = bz;
 904
 905         sysctl_ctx_init(&bz->sysctl_ctx);
 906         bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
 907             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
 908             CTLFLAG_RD, 0, "");
 909         if (bz->sysctl_tree == NULL) {
 910                 sysctl_ctx_free(&bz->sysctl_ctx);
 911                 return 0;       /* XXX error code? */
 912         }
 913
 914         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 915             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 916             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
 917             "Total bounce pages");
 918         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 919             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 920             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
 921             "Free bounce pages");
 922         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 923             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 924             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
 925             "Reserved bounce pages");
 926         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 927             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 928             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
 929             "Active bounce pages");
 930         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 931             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 932             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
 933             "Total bounce requests");
 934         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 935             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 936             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
 937             "Total bounce requests that were deferred");
 938         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 939             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 940             "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
 941             "Total bounce page reservations that were failed");
 942         SYSCTL_ADD_STRING(&bz->sysctl_ctx,
 943             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 944             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
 945         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 946             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 947             "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
 948         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 949             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 950             "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
 951
 952         return 0;
 953 }
 954
 955 static int
 956 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 957 {
 958         struct bounce_zone *bz = dmat->bounce_zone;
 959         int count = 0;
 960
 961         while (numpages > 0) {
 962                 struct bounce_page *bpage;
 963
 964                 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
 965
 966                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 967                                                          M_NOWAIT, 0ul,
 968                                                          dmat->lowaddr,
 969                                                          PAGE_SIZE,
 970                                                          0);
 971                 if (bpage->vaddr == 0) {
 972                         kfree(bpage, M_DEVBUF);
 973                         break;
 974                 }
 975                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 976
 977                 crit_enter();
 978                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
 979                 total_bounce_pages++;
 980                 bz->total_bpages++;
 981                 bz->free_bpages++;
 982                 crit_exit();
 983
 984                 count++;
 985                 numpages--;
 986         }
 987         return count;
 988 }
 989
 990 static int
 991 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
 992 {
 993         struct bounce_zone *bz = dmat->bounce_zone;
 994         int pages;
 995
 996         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
 997         if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
 998                 bz->reserve_failed++;
 999                 return (map->pagesneeded - (map->pagesreserved + pages));
1000         }
1001         bz->free_bpages -= pages;
1002         bz->reserved_bpages += pages;
1003         map->pagesreserved += pages;
1004         pages = map->pagesneeded - map->pagesreserved;
1005
1006         return pages;
1007 }
1008
1009 static bus_addr_t
1010 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1011                 bus_size_t size)
1012 {
1013         struct bounce_zone *bz = dmat->bounce_zone;
1014         struct bounce_page *bpage;
1015
1016         if (map->pagesneeded == 0)
1017                 panic("add_bounce_page: map doesn't need any pages");
1018         map->pagesneeded--;
1019
1020         if (map->pagesreserved == 0)
1021                 panic("add_bounce_page: map doesn't need any pages");
1022         map->pagesreserved--;
1023
1024         crit_enter();
1025         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1026         if (bpage == NULL)
1027                 panic("add_bounce_page: free page list is empty");
1028
1029         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1030         bz->reserved_bpages--;
1031         bz->active_bpages++;
1032         crit_exit();
1033
1034         bpage->datavaddr = vaddr;
1035         bpage->datacount = size;
1036         STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1037         return bpage->busaddr;
1038 }
1039
1040 static void
1041 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1042 {
1043         struct bounce_zone *bz = dmat->bounce_zone;
1044         struct bus_dmamap *map;
1045
1046         bpage->datavaddr = 0;
1047         bpage->datacount = 0;
1048
1049         crit_enter();
1050         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1051         bz->free_bpages++;
1052         bz->active_bpages--;
1053         if ((map = STAILQ_FIRST(&bz->bounce_map_waitinglist)) != NULL) {
1054                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1055                         STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1056                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1057                                            map, links);
1058                         busdma_swi_pending = 1;
1059                         bz->total_deferred++;
1060                         setsoftvm();
1061                 }
1062         }
1063         crit_exit();
1064 }
1065
1066 void
1067 busdma_swi(void)
1068 {
1069         struct bus_dmamap *map;
1070
1071         crit_enter();
1072         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1073                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1074                 crit_exit();
1075                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1076                                 map->callback, map->callback_arg, /*flags*/0);
1077                 crit_enter();
1078         }
1079         crit_exit();
1080 }