sys/x86/x86/busdma_bounce.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
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/malloc.h>
  33 #include <sys/bus.h>
  34 #include <sys/interrupt.h>
  35 #include <sys/kernel.h>
  36 #include <sys/ktr.h>
  37 #include <sys/lock.h>
  38 #include <sys/proc.h>
  39 #include <sys/memdesc.h>
  40 #include <sys/mutex.h>
  41 #include <sys/sysctl.h>
  42 #include <sys/uio.h>
  43
  44 #include <vm/vm.h>
  45 #include <vm/vm_extern.h>
  46 #include <vm/vm_kern.h>
  47 #include <vm/vm_page.h>
  48 #include <vm/vm_map.h>
  49
  50 #include <machine/atomic.h>
  51 #include <machine/bus.h>
  52 #include <machine/md_var.h>
  53 #include <machine/specialreg.h>
  54 #include <x86/include/busdma_impl.h>
  55
  56 #ifdef __i386__
  57 #define MAX_BPAGES 512
  58 #else
  59 #define MAX_BPAGES 8192
  60 #endif
  61
  62 enum {
  63         BUS_DMA_COULD_BOUNCE    = 0x01,
  64         BUS_DMA_MIN_ALLOC_COMP  = 0x02,
  65         BUS_DMA_KMEM_ALLOC      = 0x04,
  66 };
  67
  68 struct bounce_zone;
  69
  70 struct bus_dma_tag {
  71         struct bus_dma_tag_common common;
  72         int                     map_count;
  73         int                     bounce_flags;
  74         bus_dma_segment_t       *segments;
  75         struct bounce_zone      *bounce_zone;
  76 };
  77
  78 struct bounce_page {
  79         vm_offset_t     vaddr;          /* kva of bounce buffer */
  80         bus_addr_t      busaddr;        /* Physical address */
  81         vm_offset_t     datavaddr;      /* kva of client data */
  82         vm_offset_t     dataoffs;       /* page offset of client data */
  83         vm_page_t       datapage[2];    /* physical page(s) of client data */
  84         bus_size_t      datacount;      /* client data count */
  85         STAILQ_ENTRY(bounce_page) links;
  86 };
  87
  88 int busdma_swi_pending;
  89
  90 struct bounce_zone {
  91         STAILQ_ENTRY(bounce_zone) links;
  92         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  93         int             total_bpages;
  94         int             free_bpages;
  95         int             reserved_bpages;
  96         int             active_bpages;
  97         int             total_bounced;
  98         int             total_deferred;
  99         int             map_count;
 100         bus_size_t      alignment;
 101         bus_addr_t      lowaddr;
 102         char            zoneid[8];
 103         char            lowaddrid[20];
 104         struct sysctl_ctx_list sysctl_tree;
 105         struct sysctl_oid *sysctl_tree_top;
 106 };
 107
 108 static struct mtx bounce_lock;
 109 static int total_bpages;
 110 static int busdma_zonecount;
 111 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
 112
 113 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 114 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 115            "Total bounce pages");
 116
 117 struct bus_dmamap {
 118         struct bp_list         bpages;
 119         int                    pagesneeded;
 120         int                    pagesreserved;
 121         bus_dma_tag_t          dmat;
 122         struct memdesc         mem;
 123         bus_dmamap_callback_t *callback;
 124         void                  *callback_arg;
 125         STAILQ_ENTRY(bus_dmamap) links;
 126 };
 127
 128 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 129 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 130 static struct bus_dmamap nobounce_dmamap;
 131
 132 static void init_bounce_pages(void *dummy);
 133 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 134 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 135 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 136                                 int commit);
 137 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 138                                   vm_offset_t vaddr, bus_addr_t addr1,
 139                                   bus_addr_t addr2, bus_size_t size);
 140 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 141 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 142 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 143                                     pmap_t pmap, void *buf, bus_size_t buflen,
 144                                     int flags);
 145 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 146                                    vm_paddr_t buf, bus_size_t buflen,
 147                                    int flags);
 148 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 149                                      int flags);
 150
 151 /*
 152  * Allocate a device specific dma_tag.
 153  */
 154 static int
 155 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 156     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 157     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 158     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 159     void *lockfuncarg, bus_dma_tag_t *dmat)
 160 {
 161         bus_dma_tag_t newtag;
 162         int error;
 163
 164         *dmat = NULL;
 165         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 166             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 167             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 168             sizeof (struct bus_dma_tag), (void **)&newtag);
 169         if (error != 0)
 170                 return (error);
 171
 172         newtag->common.impl = &bus_dma_bounce_impl;
 173         newtag->map_count = 0;
 174         newtag->segments = NULL;
 175
 176         if (parent != NULL && ((newtag->common.filter != NULL) ||
 177             ((parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0)))
 178                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 179
 180         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 181             newtag->common.alignment > 1)
 182                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 183
 184         if (((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 185             (flags & BUS_DMA_ALLOCNOW) != 0) {
 186                 struct bounce_zone *bz;
 187
 188                 /* Must bounce */
 189                 if ((error = alloc_bounce_zone(newtag)) != 0) {
 190                         free(newtag, M_DEVBUF);
 191                         return (error);
 192                 }
 193                 bz = newtag->bounce_zone;
 194
 195                 if (ptoa(bz->total_bpages) < maxsize) {
 196                         int pages;
 197
 198                         pages = atop(maxsize) - bz->total_bpages;
 199
 200                         /* Add pages to our bounce pool */
 201                         if (alloc_bounce_pages(newtag, pages) < pages)
 202                                 error = ENOMEM;
 203                 }
 204                 /* Performed initial allocation */
 205                 newtag->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 206         } else
 207                 error = 0;
 208
 209         if (error != 0)
 210                 free(newtag, M_DEVBUF);
 211         else
 212                 *dmat = newtag;
 213         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 214             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 215             error);
 216         return (error);
 217 }
 218
 219 static int
 220 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 221 {
 222         bus_dma_tag_t dmat_copy, parent;
 223         int error;
 224
 225         error = 0;
 226         dmat_copy = dmat;
 227
 228         if (dmat != NULL) {
 229                 if (dmat->map_count != 0) {
 230                         error = EBUSY;
 231                         goto out;
 232                 }
 233                 while (dmat != NULL) {
 234                         parent = (bus_dma_tag_t)dmat->common.parent;
 235                         atomic_subtract_int(&dmat->common.ref_count, 1);
 236                         if (dmat->common.ref_count == 0) {
 237                                 if (dmat->segments != NULL)
 238                                         free(dmat->segments, M_DEVBUF);
 239                                 free(dmat, M_DEVBUF);
 240                                 /*
 241                                  * Last reference count, so
 242                                  * release our reference
 243                                  * count on our parent.
 244                                  */
 245                                 dmat = parent;
 246                         } else
 247                                 dmat = NULL;
 248                 }
 249         }
 250 out:
 251         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 252         return (error);
 253 }
 254
 255 /*
 256  * Allocate a handle for mapping from kva/uva/physical
 257  * address space into bus device space.
 258  */
 259 static int
 260 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 261 {
 262         struct bounce_zone *bz;
 263         int error, maxpages, pages;
 264
 265         error = 0;
 266
 267         if (dmat->segments == NULL) {
 268                 dmat->segments = (bus_dma_segment_t *)malloc(
 269                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 270                     M_DEVBUF, M_NOWAIT);
 271                 if (dmat->segments == NULL) {
 272                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 273                             __func__, dmat, ENOMEM);
 274                         return (ENOMEM);
 275                 }
 276         }
 277
 278         /*
 279          * Bouncing might be required if the driver asks for an active
 280          * exclusion region, a data alignment that is stricter than 1, and/or
 281          * an active address boundary.
 282          */
 283         if (dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) {
 284                 /* Must bounce */
 285                 if (dmat->bounce_zone == NULL) {
 286                         if ((error = alloc_bounce_zone(dmat)) != 0)
 287                                 return (error);
 288                 }
 289                 bz = dmat->bounce_zone;
 290
 291                 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 292                     M_NOWAIT | M_ZERO);
 293                 if (*mapp == NULL) {
 294                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 295                             __func__, dmat, ENOMEM);
 296                         return (ENOMEM);
 297                 }
 298
 299                 /* Initialize the new map */
 300                 STAILQ_INIT(&((*mapp)->bpages));
 301
 302                 /*
 303                  * Attempt to add pages to our pool on a per-instance
 304                  * basis up to a sane limit.
 305                  */
 306                 if (dmat->common.alignment > 1)
 307                         maxpages = MAX_BPAGES;
 308                 else
 309                         maxpages = MIN(MAX_BPAGES, Maxmem -
 310                             atop(dmat->common.lowaddr));
 311                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 312                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 313                         pages = MAX(atop(dmat->common.maxsize), 1);
 314                         pages = MIN(maxpages - bz->total_bpages, pages);
 315                         pages = MAX(pages, 1);
 316                         if (alloc_bounce_pages(dmat, pages) < pages)
 317                                 error = ENOMEM;
 318                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 319                             == 0) {
 320                                 if (error == 0) {
 321                                         dmat->bounce_flags |=
 322                                             BUS_DMA_MIN_ALLOC_COMP;
 323                                 }
 324                         } else
 325                                 error = 0;
 326                 }
 327                 bz->map_count++;
 328         } else {
 329                 *mapp = NULL;
 330         }
 331         if (error == 0)
 332                 dmat->map_count++;
 333         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 334             __func__, dmat, dmat->common.flags, error);
 335         return (error);
 336 }
 337
 338 /*
 339  * Destroy a handle for mapping from kva/uva/physical
 340  * address space into bus device space.
 341  */
 342 static int
 343 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 344 {
 345
 346         if (map != NULL && map != &nobounce_dmamap) {
 347                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 348                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 349                             __func__, dmat, EBUSY);
 350                         return (EBUSY);
 351                 }
 352                 if (dmat->bounce_zone)
 353                         dmat->bounce_zone->map_count--;
 354                 free(map, M_DEVBUF);
 355         }
 356         dmat->map_count--;
 357         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 358         return (0);
 359 }
 360
 361
 362 /*
 363  * Allocate a piece of memory that can be efficiently mapped into
 364  * bus device space based on the constraints lited in the dma tag.
 365  * A dmamap to for use with dmamap_load is also allocated.
 366  */
 367 static int
 368 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 369     bus_dmamap_t *mapp)
 370 {
 371         vm_memattr_t attr;
 372         int mflags;
 373
 374         if (flags & BUS_DMA_NOWAIT)
 375                 mflags = M_NOWAIT;
 376         else
 377                 mflags = M_WAITOK;
 378
 379         /* If we succeed, no mapping/bouncing will be required */
 380         *mapp = NULL;
 381
 382         if (dmat->segments == NULL) {
 383                 dmat->segments = (bus_dma_segment_t *)malloc(
 384                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 385                     M_DEVBUF, mflags);
 386                 if (dmat->segments == NULL) {
 387                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 388                             __func__, dmat, dmat->common.flags, ENOMEM);
 389                         return (ENOMEM);
 390                 }
 391         }
 392         if (flags & BUS_DMA_ZERO)
 393                 mflags |= M_ZERO;
 394         if (flags & BUS_DMA_NOCACHE)
 395                 attr = VM_MEMATTR_UNCACHEABLE;
 396         else
 397                 attr = VM_MEMATTR_DEFAULT;
 398
 399         /*
 400          * Allocate the buffer from the malloc(9) allocator if...
 401          *  - It's small enough to fit into a single power of two sized bucket.
 402          *  - The alignment is less than or equal to the maximum size
 403          *  - The low address requirement is fulfilled.
 404          * else allocate non-contiguous pages if...
 405          *  - The page count that could get allocated doesn't exceed
 406          *    nsegments also when the maximum segment size is less
 407          *    than PAGE_SIZE.
 408          *  - The alignment constraint isn't larger than a page boundary.
 409          *  - There are no boundary-crossing constraints.
 410          * else allocate a block of contiguous pages because one or more of the
 411          * constraints is something that only the contig allocator can fulfill.
 412          *
 413          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 414          * below is just a quick hack. The exact alignment guarantees
 415          * of malloc(9) need to be nailed down, and the code below
 416          * should be rewritten to take that into account.
 417          *
 418          * In the meantime warn the user if malloc gets it wrong.
 419          */
 420         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 421            (dmat->common.alignment <= dmat->common.maxsize) &&
 422             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 423             attr == VM_MEMATTR_DEFAULT) {
 424                 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
 425         } else if (dmat->common.nsegments >=
 426             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
 427             dmat->common.alignment <= PAGE_SIZE &&
 428             (dmat->common.boundary % PAGE_SIZE) == 0) {
 429                 /* Page-based multi-segment allocations allowed */
 430                 *vaddr = (void *)kmem_alloc_attr(kernel_arena,
 431                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 432                     attr);
 433                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 434         } else {
 435                 *vaddr = (void *)kmem_alloc_contig(kernel_arena,
 436                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 437                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 438                     dmat->common.boundary, attr);
 439                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 440         }
 441         if (*vaddr == NULL) {
 442                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 443                     __func__, dmat, dmat->common.flags, ENOMEM);
 444                 return (ENOMEM);
 445         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 446                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 447         }
 448         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 449             __func__, dmat, dmat->common.flags, 0);
 450         return (0);
 451 }
 452
 453 /*
 454  * Free a piece of memory and it's allociated dmamap, that was allocated
 455  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 456  */
 457 static void
 458 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 459 {
 460         /*
 461          * dmamem does not need to be bounced, so the map should be
 462          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 463          * was used and set if kmem_alloc_contig() was used.
 464          */
 465         if (map != NULL)
 466                 panic("bus_dmamem_free: Invalid map freed\n");
 467         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 468                 free(vaddr, M_DEVBUF);
 469         else
 470                 kmem_free(kernel_arena, (vm_offset_t)vaddr,
 471                     dmat->common.maxsize);
 472         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 473             dmat->bounce_flags);
 474 }
 475
 476 static void
 477 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 478     bus_size_t buflen, int flags)
 479 {
 480         bus_addr_t curaddr;
 481         bus_size_t sgsize;
 482
 483         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 484                 /*
 485                  * Count the number of bounce pages
 486                  * needed in order to complete this transfer
 487                  */
 488                 curaddr = buf;
 489                 while (buflen != 0) {
 490                         sgsize = MIN(buflen, dmat->common.maxsegsz);
 491                         if (bus_dma_run_filter(&dmat->common, curaddr)) {
 492                                 sgsize = MIN(sgsize,
 493                                     PAGE_SIZE - (curaddr & PAGE_MASK));
 494                                 map->pagesneeded++;
 495                         }
 496                         curaddr += sgsize;
 497                         buflen -= sgsize;
 498                 }
 499                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 500         }
 501 }
 502
 503 static void
 504 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 505     void *buf, bus_size_t buflen, int flags)
 506 {
 507         vm_offset_t vaddr;
 508         vm_offset_t vendaddr;
 509         bus_addr_t paddr;
 510         bus_size_t sg_len;
 511
 512         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 513                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 514                     "alignment= %d", dmat->common.lowaddr,
 515                     ptoa((vm_paddr_t)Maxmem),
 516                     dmat->common.boundary, dmat->common.alignment);
 517                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 518                     map, &nobounce_dmamap, map->pagesneeded);
 519                 /*
 520                  * Count the number of bounce pages
 521                  * needed in order to complete this transfer
 522                  */
 523                 vaddr = (vm_offset_t)buf;
 524                 vendaddr = (vm_offset_t)buf + buflen;
 525
 526                 while (vaddr < vendaddr) {
 527                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 528                         if (pmap == kernel_pmap)
 529                                 paddr = pmap_kextract(vaddr);
 530                         else
 531                                 paddr = pmap_extract(pmap, vaddr);
 532                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 533                                 sg_len = roundup2(sg_len,
 534                                     dmat->common.alignment);
 535                                 map->pagesneeded++;
 536                         }
 537                         vaddr += sg_len;
 538                 }
 539                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 540         }
 541 }
 542
 543 static void
 544 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 545     int ma_offs, bus_size_t buflen, int flags)
 546 {
 547         bus_size_t sg_len, max_sgsize;
 548         int page_index;
 549         vm_paddr_t paddr;
 550
 551         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 552                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 553                     "alignment= %d", dmat->common.lowaddr,
 554                     ptoa((vm_paddr_t)Maxmem),
 555                     dmat->common.boundary, dmat->common.alignment);
 556                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 557                     map, &nobounce_dmamap, map->pagesneeded);
 558
 559                 /*
 560                  * Count the number of bounce pages
 561                  * needed in order to complete this transfer
 562                  */
 563                 page_index = 0;
 564                 while (buflen > 0) {
 565                         paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 566                         sg_len = PAGE_SIZE - ma_offs;
 567                         max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 568                         sg_len = MIN(sg_len, max_sgsize);
 569                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 570                                 sg_len = roundup2(sg_len,
 571                                     dmat->common.alignment);
 572                                 sg_len = MIN(sg_len, max_sgsize);
 573                                 KASSERT((sg_len & (dmat->common.alignment - 1))
 574                                     == 0, ("Segment size is not aligned"));
 575                                 map->pagesneeded++;
 576                         }
 577                         if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
 578                                 page_index++;
 579                         ma_offs = (ma_offs + sg_len) & PAGE_MASK;
 580                         KASSERT(buflen >= sg_len,
 581                             ("Segment length overruns original buffer"));
 582                         buflen -= sg_len;
 583                 }
 584                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 585         }
 586 }
 587
 588 static int
 589 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 590 {
 591
 592         /* Reserve Necessary Bounce Pages */
 593         mtx_lock(&bounce_lock);
 594         if (flags & BUS_DMA_NOWAIT) {
 595                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 596                         mtx_unlock(&bounce_lock);
 597                         return (ENOMEM);
 598                 }
 599         } else {
 600                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 601                         /* Queue us for resources */
 602                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 603                         mtx_unlock(&bounce_lock);
 604                         return (EINPROGRESS);
 605                 }
 606         }
 607         mtx_unlock(&bounce_lock);
 608
 609         return (0);
 610 }
 611
 612 /*
 613  * Add a single contiguous physical range to the segment list.
 614  */
 615 static int
 616 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 617     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 618 {
 619         bus_addr_t baddr, bmask;
 620         int seg;
 621
 622         /*
 623          * Make sure we don't cross any boundaries.
 624          */
 625         bmask = ~(dmat->common.boundary - 1);
 626         if (dmat->common.boundary > 0) {
 627                 baddr = (curaddr + dmat->common.boundary) & bmask;
 628                 if (sgsize > (baddr - curaddr))
 629                         sgsize = (baddr - curaddr);
 630         }
 631
 632         /*
 633          * Insert chunk into a segment, coalescing with
 634          * previous segment if possible.
 635          */
 636         seg = *segp;
 637         if (seg == -1) {
 638                 seg = 0;
 639                 segs[seg].ds_addr = curaddr;
 640                 segs[seg].ds_len = sgsize;
 641         } else {
 642                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 643                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 644                     (dmat->common.boundary == 0 ||
 645                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 646                         segs[seg].ds_len += sgsize;
 647                 else {
 648                         if (++seg >= dmat->common.nsegments)
 649                                 return (0);
 650                         segs[seg].ds_addr = curaddr;
 651                         segs[seg].ds_len = sgsize;
 652                 }
 653         }
 654         *segp = seg;
 655         return (sgsize);
 656 }
 657
 658 /*
 659  * Utility function to load a physical buffer.  segp contains
 660  * the starting segment on entrace, and the ending segment on exit.
 661  */
 662 static int
 663 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 664     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 665     int *segp)
 666 {
 667         bus_size_t sgsize;
 668         bus_addr_t curaddr;
 669         int error;
 670
 671         if (map == NULL)
 672                 map = &nobounce_dmamap;
 673
 674         if (segs == NULL)
 675                 segs = dmat->segments;
 676
 677         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 678                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 679                 if (map->pagesneeded != 0) {
 680                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 681                         if (error)
 682                                 return (error);
 683                 }
 684         }
 685
 686         while (buflen > 0) {
 687                 curaddr = buf;
 688                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 689                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 690                     map->pagesneeded != 0 &&
 691                     bus_dma_run_filter(&dmat->common, curaddr)) {
 692                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 693                         curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
 694                             sgsize);
 695                 }
 696                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 697                     segp);
 698                 if (sgsize == 0)
 699                         break;
 700                 buf += sgsize;
 701                 buflen -= sgsize;
 702         }
 703
 704         /*
 705          * Did we fit?
 706          */
 707         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 708 }
 709
 710 /*
 711  * Utility function to load a linear buffer.  segp contains
 712  * the starting segment on entrace, and the ending segment on exit.
 713  */
 714 static int
 715 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 716     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 717     int *segp)
 718 {
 719         bus_size_t sgsize, max_sgsize;
 720         bus_addr_t curaddr;
 721         vm_offset_t kvaddr, vaddr;
 722         int error;
 723
 724         if (map == NULL)
 725                 map = &nobounce_dmamap;
 726
 727         if (segs == NULL)
 728                 segs = dmat->segments;
 729
 730         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 731                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 732                 if (map->pagesneeded != 0) {
 733                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 734                         if (error)
 735                                 return (error);
 736                 }
 737         }
 738
 739         vaddr = (vm_offset_t)buf;
 740         while (buflen > 0) {
 741                 /*
 742                  * Get the physical address for this segment.
 743                  */
 744                 if (pmap == kernel_pmap) {
 745                         curaddr = pmap_kextract(vaddr);
 746                         kvaddr = vaddr;
 747                 } else {
 748                         curaddr = pmap_extract(pmap, vaddr);
 749                         kvaddr = 0;
 750                 }
 751
 752                 /*
 753                  * Compute the segment size, and adjust counts.
 754                  */
 755                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 756                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 757                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 758                     map->pagesneeded != 0 &&
 759                     bus_dma_run_filter(&dmat->common, curaddr)) {
 760                         sgsize = roundup2(sgsize, dmat->common.alignment);
 761                         sgsize = MIN(sgsize, max_sgsize);
 762                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 763                             sgsize);
 764                 } else {
 765                         sgsize = MIN(sgsize, max_sgsize);
 766                 }
 767                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 768                     segp);
 769                 if (sgsize == 0)
 770                         break;
 771                 vaddr += sgsize;
 772                 buflen -= sgsize;
 773         }
 774
 775         /*
 776          * Did we fit?
 777          */
 778         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 779 }
 780
 781 static int
 782 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 783     struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
 784     bus_dma_segment_t *segs, int *segp)
 785 {
 786         vm_paddr_t paddr, next_paddr;
 787         int error, page_index;
 788         bus_size_t sgsize, max_sgsize;
 789
 790         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 791                 /*
 792                  * If we have to keep the offset of each page this function
 793                  * is not suitable, switch back to bus_dmamap_load_ma_triv
 794                  * which is going to do the right thing in this case.
 795                  */
 796                 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
 797                     flags, segs, segp);
 798                 return (error);
 799         }
 800
 801         if (map == NULL)
 802                 map = &nobounce_dmamap;
 803
 804         if (segs == NULL)
 805                 segs = dmat->segments;
 806
 807         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 808                 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
 809                 if (map->pagesneeded != 0) {
 810                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 811                         if (error)
 812                                 return (error);
 813                 }
 814         }
 815
 816         page_index = 0;
 817         while (buflen > 0) {
 818                 /*
 819                  * Compute the segment size, and adjust counts.
 820                  */
 821                 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 822                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 823                 sgsize = PAGE_SIZE - ma_offs;
 824                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 825                     map->pagesneeded != 0 &&
 826                     bus_dma_run_filter(&dmat->common, paddr)) {
 827                         sgsize = roundup2(sgsize, dmat->common.alignment);
 828                         sgsize = MIN(sgsize, max_sgsize);
 829                         KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
 830                             ("Segment size is not aligned"));
 831                         /*
 832                          * Check if two pages of the user provided buffer
 833                          * are used.
 834                          */
 835                         if ((ma_offs + sgsize) > PAGE_SIZE)
 836                                 next_paddr =
 837                                     VM_PAGE_TO_PHYS(ma[page_index + 1]);
 838                         else
 839                                 next_paddr = 0;
 840                         paddr = add_bounce_page(dmat, map, 0, paddr,
 841                             next_paddr, sgsize);
 842                 } else {
 843                         sgsize = MIN(sgsize, max_sgsize);
 844                 }
 845                 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
 846                     segp);
 847                 if (sgsize == 0)
 848                         break;
 849                 KASSERT(buflen >= sgsize,
 850                     ("Segment length overruns original buffer"));
 851                 buflen -= sgsize;
 852                 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
 853                         page_index++;
 854                 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
 855         }
 856
 857         /*
 858          * Did we fit?
 859          */
 860         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 861 }
 862
 863 static void
 864 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 865     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 866 {
 867
 868         if (map == NULL)
 869                 return;
 870         map->mem = *mem;
 871         map->dmat = dmat;
 872         map->callback = callback;
 873         map->callback_arg = callback_arg;
 874 }
 875
 876 static bus_dma_segment_t *
 877 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 878     bus_dma_segment_t *segs, int nsegs, int error)
 879 {
 880
 881         if (segs == NULL)
 882                 segs = dmat->segments;
 883         return (segs);
 884 }
 885
 886 /*
 887  * Release the mapping held by map.
 888  */
 889 static void
 890 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 891 {
 892         struct bounce_page *bpage;
 893
 894         if (map == NULL)
 895                 return;
 896
 897         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 898                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 899                 free_bounce_page(dmat, bpage);
 900         }
 901 }
 902
 903 static void
 904 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 905     bus_dmasync_op_t op)
 906 {
 907         struct bounce_page *bpage;
 908         vm_offset_t datavaddr, tempvaddr;
 909         bus_size_t datacount1, datacount2;
 910
 911         if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 912                 return;
 913
 914         /*
 915          * Handle data bouncing.  We might also want to add support for
 916          * invalidating the caches on broken hardware.
 917          */
 918         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 919             "performing bounce", __func__, dmat, dmat->common.flags, op);
 920
 921         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 922                 while (bpage != NULL) {
 923                         tempvaddr = 0;
 924                         datavaddr = bpage->datavaddr;
 925                         datacount1 = bpage->datacount;
 926                         if (datavaddr == 0) {
 927                                 tempvaddr =
 928                                     pmap_quick_enter_page(bpage->datapage[0]);
 929                                 datavaddr = tempvaddr | bpage->dataoffs;
 930                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 931                                     datacount1);
 932                         }
 933
 934                         bcopy((void *)datavaddr,
 935                             (void *)bpage->vaddr, datacount1);
 936
 937                         if (tempvaddr != 0)
 938                                 pmap_quick_remove_page(tempvaddr);
 939
 940                         if (bpage->datapage[1] == 0) {
 941                                 KASSERT(datacount1 == bpage->datacount,
 942                 ("Mismatch between data size and provided memory space"));
 943                                 goto next_w;
 944                         }
 945
 946                         /*
 947                          * We are dealing with an unmapped buffer that expands
 948                          * over two pages.
 949                          */
 950                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
 951                         datacount2 = bpage->datacount - datacount1;
 952                         bcopy((void *)datavaddr,
 953                             (void *)(bpage->vaddr + datacount1), datacount2);
 954                         pmap_quick_remove_page(datavaddr);
 955
 956 next_w:
 957                         bpage = STAILQ_NEXT(bpage, links);
 958                 }
 959                 dmat->bounce_zone->total_bounced++;
 960         }
 961
 962         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
 963                 while (bpage != NULL) {
 964                         tempvaddr = 0;
 965                         datavaddr = bpage->datavaddr;
 966                         datacount1 = bpage->datacount;
 967                         if (datavaddr == 0) {
 968                                 tempvaddr =
 969                                     pmap_quick_enter_page(bpage->datapage[0]);
 970                                 datavaddr = tempvaddr | bpage->dataoffs;
 971                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 972                                     datacount1);
 973                         }
 974
 975                         bcopy((void *)bpage->vaddr, (void *)datavaddr,
 976                             datacount1);
 977
 978                         if (tempvaddr != 0)
 979                                 pmap_quick_remove_page(tempvaddr);
 980
 981                         if (bpage->datapage[1] == 0) {
 982                                 KASSERT(datacount1 == bpage->datacount,
 983                 ("Mismatch between data size and provided memory space"));
 984                                 goto next_r;
 985                         }
 986
 987                         /*
 988                          * We are dealing with an unmapped buffer that expands
 989                          * over two pages.
 990                          */
 991                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
 992                         datacount2 = bpage->datacount - datacount1;
 993                         bcopy((void *)(bpage->vaddr + datacount1),
 994                             (void *)datavaddr, datacount2);
 995                         pmap_quick_remove_page(datavaddr);
 996
 997 next_r:
 998                         bpage = STAILQ_NEXT(bpage, links);
 999                 }
1000                 dmat->bounce_zone->total_bounced++;
1001         }
1002 }
1003
1004 static void
1005 init_bounce_pages(void *dummy __unused)
1006 {
1007
1008         total_bpages = 0;
1009         STAILQ_INIT(&bounce_zone_list);
1010         STAILQ_INIT(&bounce_map_waitinglist);
1011         STAILQ_INIT(&bounce_map_callbacklist);
1012         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1013 }
1014 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1015
1016 static struct sysctl_ctx_list *
1017 busdma_sysctl_tree(struct bounce_zone *bz)
1018 {
1019
1020         return (&bz->sysctl_tree);
1021 }
1022
1023 static struct sysctl_oid *
1024 busdma_sysctl_tree_top(struct bounce_zone *bz)
1025 {
1026
1027         return (bz->sysctl_tree_top);
1028 }
1029
1030 static int
1031 alloc_bounce_zone(bus_dma_tag_t dmat)
1032 {
1033         struct bounce_zone *bz;
1034
1035         /* Check to see if we already have a suitable zone */
1036         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1037                 if ((dmat->common.alignment <= bz->alignment) &&
1038                     (dmat->common.lowaddr >= bz->lowaddr)) {
1039                         dmat->bounce_zone = bz;
1040                         return (0);
1041                 }
1042         }
1043
1044         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1045             M_NOWAIT | M_ZERO)) == NULL)
1046                 return (ENOMEM);
1047
1048         STAILQ_INIT(&bz->bounce_page_list);
1049         bz->free_bpages = 0;
1050         bz->reserved_bpages = 0;
1051         bz->active_bpages = 0;
1052         bz->lowaddr = dmat->common.lowaddr;
1053         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1054         bz->map_count = 0;
1055         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1056         busdma_zonecount++;
1057         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1058         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1059         dmat->bounce_zone = bz;
1060
1061         sysctl_ctx_init(&bz->sysctl_tree);
1062         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1063             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1064             CTLFLAG_RD, 0, "");
1065         if (bz->sysctl_tree_top == NULL) {
1066                 sysctl_ctx_free(&bz->sysctl_tree);
1067                 return (0);     /* XXX error code? */
1068         }
1069
1070         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1071             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1072             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1073             "Total bounce pages");
1074         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1075             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1076             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1077             "Free bounce pages");
1078         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1079             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1080             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1081             "Reserved bounce pages");
1082         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1083             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1084             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1085             "Active bounce pages");
1086         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1087             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1088             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1089             "Total bounce requests");
1090         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1091             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1092             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1093             "Total bounce requests that were deferred");
1094         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1095             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1096             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1097         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1098             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1099             "alignment", CTLFLAG_RD, &bz->alignment, "");
1100
1101         return (0);
1102 }
1103
1104 static int
1105 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1106 {
1107         struct bounce_zone *bz;
1108         int count;
1109
1110         bz = dmat->bounce_zone;
1111         count = 0;
1112         while (numpages > 0) {
1113                 struct bounce_page *bpage;
1114
1115                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1116                                                      M_NOWAIT | M_ZERO);
1117
1118                 if (bpage == NULL)
1119                         break;
1120                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1121                                                          M_NOWAIT, 0ul,
1122                                                          bz->lowaddr,
1123                                                          PAGE_SIZE,
1124                                                          0);
1125                 if (bpage->vaddr == 0) {
1126                         free(bpage, M_DEVBUF);
1127                         break;
1128                 }
1129                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1130                 mtx_lock(&bounce_lock);
1131                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1132                 total_bpages++;
1133                 bz->total_bpages++;
1134                 bz->free_bpages++;
1135                 mtx_unlock(&bounce_lock);
1136                 count++;
1137                 numpages--;
1138         }
1139         return (count);
1140 }
1141
1142 static int
1143 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1144 {
1145         struct bounce_zone *bz;
1146         int pages;
1147
1148         mtx_assert(&bounce_lock, MA_OWNED);
1149         bz = dmat->bounce_zone;
1150         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1151         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1152                 return (map->pagesneeded - (map->pagesreserved + pages));
1153         bz->free_bpages -= pages;
1154         bz->reserved_bpages += pages;
1155         map->pagesreserved += pages;
1156         pages = map->pagesneeded - map->pagesreserved;
1157
1158         return (pages);
1159 }
1160
1161 static bus_addr_t
1162 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1163                 bus_addr_t addr1, bus_addr_t addr2, bus_size_t size)
1164 {
1165         struct bounce_zone *bz;
1166         struct bounce_page *bpage;
1167
1168         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1169         KASSERT(map != NULL && map != &nobounce_dmamap,
1170             ("add_bounce_page: bad map %p", map));
1171
1172         bz = dmat->bounce_zone;
1173         if (map->pagesneeded == 0)
1174                 panic("add_bounce_page: map doesn't need any pages");
1175         map->pagesneeded--;
1176
1177         if (map->pagesreserved == 0)
1178                 panic("add_bounce_page: map doesn't need any pages");
1179         map->pagesreserved--;
1180
1181         mtx_lock(&bounce_lock);
1182         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1183         if (bpage == NULL)
1184                 panic("add_bounce_page: free page list is empty");
1185
1186         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1187         bz->reserved_bpages--;
1188         bz->active_bpages++;
1189         mtx_unlock(&bounce_lock);
1190
1191         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1192                 /* Page offset needs to be preserved. */
1193                 bpage->vaddr |= addr1 & PAGE_MASK;
1194                 bpage->busaddr |= addr1 & PAGE_MASK;
1195                 KASSERT(addr2 == 0,
1196         ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1197         }
1198         bpage->datavaddr = vaddr;
1199         bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1200         KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1201         bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1202         bpage->dataoffs = addr1 & PAGE_MASK;
1203         bpage->datacount = size;
1204         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1205         return (bpage->busaddr);
1206 }
1207
1208 static void
1209 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1210 {
1211         struct bus_dmamap *map;
1212         struct bounce_zone *bz;
1213
1214         bz = dmat->bounce_zone;
1215         bpage->datavaddr = 0;
1216         bpage->datacount = 0;
1217         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1218                 /*
1219                  * Reset the bounce page to start at offset 0.  Other uses
1220                  * of this bounce page may need to store a full page of
1221                  * data and/or assume it starts on a page boundary.
1222                  */
1223                 bpage->vaddr &= ~PAGE_MASK;
1224                 bpage->busaddr &= ~PAGE_MASK;
1225         }
1226
1227         mtx_lock(&bounce_lock);
1228         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1229         bz->free_bpages++;
1230         bz->active_bpages--;
1231         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1232                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1233                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1234                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1235                             map, links);
1236                         busdma_swi_pending = 1;
1237                         bz->total_deferred++;
1238                         swi_sched(vm_ih, 0);
1239                 }
1240         }
1241         mtx_unlock(&bounce_lock);
1242 }
1243
1244 void
1245 busdma_swi(void)
1246 {
1247         bus_dma_tag_t dmat;
1248         struct bus_dmamap *map;
1249
1250         mtx_lock(&bounce_lock);
1251         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1252                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1253                 mtx_unlock(&bounce_lock);
1254                 dmat = map->dmat;
1255                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1256                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1257                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1258                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1259                     BUS_DMA_UNLOCK);
1260                 mtx_lock(&bounce_lock);
1261         }
1262         mtx_unlock(&bounce_lock);
1263 }
1264
1265 struct bus_dma_impl bus_dma_bounce_impl = {
1266         .tag_create = bounce_bus_dma_tag_create,
1267         .tag_destroy = bounce_bus_dma_tag_destroy,
1268         .map_create = bounce_bus_dmamap_create,
1269         .map_destroy = bounce_bus_dmamap_destroy,
1270         .mem_alloc = bounce_bus_dmamem_alloc,
1271         .mem_free = bounce_bus_dmamem_free,
1272         .load_phys = bounce_bus_dmamap_load_phys,
1273         .load_buffer = bounce_bus_dmamap_load_buffer,
1274         .load_ma = bounce_bus_dmamap_load_ma,
1275         .map_waitok = bounce_bus_dmamap_waitok,
1276         .map_complete = bounce_bus_dmamap_complete,
1277         .map_unload = bounce_bus_dmamap_unload,
1278         .map_sync = bounce_bus_dmamap_sync
1279 };