sys/x86/x86/busdma_bounce.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1997, 1998 Justin T. Gibbs.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions, and the following disclaimer,
  12  *    without modification, immediately at the beginning of the file.
  13  * 2. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/systm.h>
  34 #include <sys/malloc.h>
  35 #include <sys/bus.h>
  36 #include <sys/interrupt.h>
  37 #include <sys/kernel.h>
  38 #include <sys/ktr.h>
  39 #include <sys/lock.h>
  40 #include <sys/proc.h>
  41 #include <sys/memdesc.h>
  42 #include <sys/mutex.h>
  43 #include <sys/sysctl.h>
  44 #include <sys/uio.h>
  45
  46 #include <vm/vm.h>
  47 #include <vm/vm_extern.h>
  48 #include <vm/vm_kern.h>
  49 #include <vm/vm_page.h>
  50 #include <vm/vm_map.h>
  51
  52 #include <machine/atomic.h>
  53 #include <machine/bus.h>
  54 #include <machine/md_var.h>
  55 #include <machine/specialreg.h>
  56 #include <x86/include/busdma_impl.h>
  57
  58 #ifdef __i386__
  59 #define MAX_BPAGES 512
  60 #else
  61 #define MAX_BPAGES 8192
  62 #endif
  63
  64 enum {
  65         BUS_DMA_COULD_BOUNCE    = 0x01,
  66         BUS_DMA_MIN_ALLOC_COMP  = 0x02,
  67         BUS_DMA_KMEM_ALLOC      = 0x04,
  68 };
  69
  70 struct bounce_zone;
  71
  72 struct bus_dma_tag {
  73         struct bus_dma_tag_common common;
  74         int                     map_count;
  75         int                     bounce_flags;
  76         bus_dma_segment_t       *segments;
  77         struct bounce_zone      *bounce_zone;
  78 };
  79
  80 struct bounce_page {
  81         vm_offset_t     vaddr;          /* kva of bounce buffer */
  82         bus_addr_t      busaddr;        /* Physical address */
  83         vm_offset_t     datavaddr;      /* kva of client data */
  84         vm_offset_t     dataoffs;       /* page offset of client data */
  85         vm_page_t       datapage[2];    /* physical page(s) of client data */
  86         bus_size_t      datacount;      /* client data count */
  87         STAILQ_ENTRY(bounce_page) links;
  88 };
  89
  90 int busdma_swi_pending;
  91
  92 struct bounce_zone {
  93         STAILQ_ENTRY(bounce_zone) links;
  94         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  95         int             total_bpages;
  96         int             free_bpages;
  97         int             reserved_bpages;
  98         int             active_bpages;
  99         int             total_bounced;
 100         int             total_deferred;
 101         int             map_count;
 102         int             domain;
 103         bus_size_t      alignment;
 104         bus_addr_t      lowaddr;
 105         char            zoneid[8];
 106         char            lowaddrid[20];
 107         struct sysctl_ctx_list sysctl_tree;
 108         struct sysctl_oid *sysctl_tree_top;
 109 };
 110
 111 static struct mtx bounce_lock;
 112 static int total_bpages;
 113 static int busdma_zonecount;
 114 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
 115
 116 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 117 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 118            "Total bounce pages");
 119
 120 struct bus_dmamap {
 121         struct bp_list         bpages;
 122         int                    pagesneeded;
 123         int                    pagesreserved;
 124         bus_dma_tag_t          dmat;
 125         struct memdesc         mem;
 126         bus_dmamap_callback_t *callback;
 127         void                  *callback_arg;
 128         STAILQ_ENTRY(bus_dmamap) links;
 129 };
 130
 131 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 132 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 133 static struct bus_dmamap nobounce_dmamap;
 134
 135 static void init_bounce_pages(void *dummy);
 136 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 137 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 138 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 139                                 int commit);
 140 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 141                                   vm_offset_t vaddr, bus_addr_t addr1,
 142                                   bus_addr_t addr2, bus_size_t size);
 143 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 144 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 145 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 146                                     pmap_t pmap, void *buf, bus_size_t buflen,
 147                                     int flags);
 148 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 149                                    vm_paddr_t buf, bus_size_t buflen,
 150                                    int flags);
 151 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 152                                      int flags);
 153
 154 static int
 155 bounce_bus_dma_zone_setup(bus_dma_tag_t dmat)
 156 {
 157         struct bounce_zone *bz;
 158         int error;
 159
 160         /* Must bounce */
 161         if ((error = alloc_bounce_zone(dmat)) != 0)
 162                 return (error);
 163         bz = dmat->bounce_zone;
 164
 165         if (ptoa(bz->total_bpages) < dmat->common.maxsize) {
 166                 int pages;
 167
 168                 pages = atop(dmat->common.maxsize) - bz->total_bpages;
 169
 170                 /* Add pages to our bounce pool */
 171                 if (alloc_bounce_pages(dmat, pages) < pages)
 172                         return (ENOMEM);
 173         }
 174         /* Performed initial allocation */
 175         dmat->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 176
 177         return (0);
 178 }
 179
 180 /*
 181  * Allocate a device specific dma_tag.
 182  */
 183 static int
 184 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 185     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 186     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 187     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 188     void *lockfuncarg, bus_dma_tag_t *dmat)
 189 {
 190         bus_dma_tag_t newtag;
 191         int error;
 192
 193         *dmat = NULL;
 194         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 195             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 196             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 197             sizeof (struct bus_dma_tag), (void **)&newtag);
 198         if (error != 0)
 199                 return (error);
 200
 201         newtag->common.impl = &bus_dma_bounce_impl;
 202         newtag->map_count = 0;
 203         newtag->segments = NULL;
 204
 205         if (parent != NULL && ((newtag->common.filter != NULL) ||
 206             ((parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0)))
 207                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 208
 209         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 210             newtag->common.alignment > 1)
 211                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 212
 213         if (((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 214             (flags & BUS_DMA_ALLOCNOW) != 0)
 215                 error = bounce_bus_dma_zone_setup(newtag);
 216         else
 217                 error = 0;
 218
 219         if (error != 0)
 220                 free(newtag, M_DEVBUF);
 221         else
 222                 *dmat = newtag;
 223         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 224             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 225             error);
 226         return (error);
 227 }
 228
 229 /*
 230  * Update the domain for the tag.  We may need to reallocate the zone and
 231  * bounce pages.
 232  */
 233 static int
 234 bounce_bus_dma_tag_set_domain(bus_dma_tag_t dmat)
 235 {
 236
 237         KASSERT(dmat->map_count == 0,
 238             ("bounce_bus_dma_tag_set_domain:  Domain set after use.\n"));
 239         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0 ||
 240             dmat->bounce_zone == NULL)
 241                 return (0);
 242         dmat->bounce_flags &= ~BUS_DMA_MIN_ALLOC_COMP;
 243         return (bounce_bus_dma_zone_setup(dmat));
 244 }
 245
 246 static int
 247 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 248 {
 249         bus_dma_tag_t dmat_copy, parent;
 250         int error;
 251
 252         error = 0;
 253         dmat_copy = dmat;
 254
 255         if (dmat != NULL) {
 256                 if (dmat->map_count != 0) {
 257                         error = EBUSY;
 258                         goto out;
 259                 }
 260                 while (dmat != NULL) {
 261                         parent = (bus_dma_tag_t)dmat->common.parent;
 262                         atomic_subtract_int(&dmat->common.ref_count, 1);
 263                         if (dmat->common.ref_count == 0) {
 264                                 if (dmat->segments != NULL)
 265                                         free_domain(dmat->segments, M_DEVBUF);
 266                                 free(dmat, M_DEVBUF);
 267                                 /*
 268                                  * Last reference count, so
 269                                  * release our reference
 270                                  * count on our parent.
 271                                  */
 272                                 dmat = parent;
 273                         } else
 274                                 dmat = NULL;
 275                 }
 276         }
 277 out:
 278         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 279         return (error);
 280 }
 281
 282 /*
 283  * Allocate a handle for mapping from kva/uva/physical
 284  * address space into bus device space.
 285  */
 286 static int
 287 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 288 {
 289         struct bounce_zone *bz;
 290         int error, maxpages, pages;
 291
 292         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
 293
 294         error = 0;
 295
 296         if (dmat->segments == NULL) {
 297                 dmat->segments = (bus_dma_segment_t *)malloc_domain(
 298                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 299                     M_DEVBUF, dmat->common.domain, M_NOWAIT);
 300                 if (dmat->segments == NULL) {
 301                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 302                             __func__, dmat, ENOMEM);
 303                         return (ENOMEM);
 304                 }
 305         }
 306
 307         /*
 308          * Bouncing might be required if the driver asks for an active
 309          * exclusion region, a data alignment that is stricter than 1, and/or
 310          * an active address boundary.
 311          */
 312         if (dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) {
 313                 /* Must bounce */
 314                 if (dmat->bounce_zone == NULL) {
 315                         if ((error = alloc_bounce_zone(dmat)) != 0)
 316                                 return (error);
 317                 }
 318                 bz = dmat->bounce_zone;
 319
 320                 *mapp = (bus_dmamap_t)malloc_domain(sizeof(**mapp), M_DEVBUF,
 321                     dmat->common.domain, M_NOWAIT | M_ZERO);
 322                 if (*mapp == NULL) {
 323                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 324                             __func__, dmat, ENOMEM);
 325                         return (ENOMEM);
 326                 }
 327
 328                 /* Initialize the new map */
 329                 STAILQ_INIT(&((*mapp)->bpages));
 330
 331                 /*
 332                  * Attempt to add pages to our pool on a per-instance
 333                  * basis up to a sane limit.
 334                  */
 335                 if (dmat->common.alignment > 1)
 336                         maxpages = MAX_BPAGES;
 337                 else
 338                         maxpages = MIN(MAX_BPAGES, Maxmem -
 339                             atop(dmat->common.lowaddr));
 340                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 341                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 342                         pages = MAX(atop(dmat->common.maxsize), 1);
 343                         pages = MIN(maxpages - bz->total_bpages, pages);
 344                         pages = MAX(pages, 1);
 345                         if (alloc_bounce_pages(dmat, pages) < pages)
 346                                 error = ENOMEM;
 347                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 348                             == 0) {
 349                                 if (error == 0) {
 350                                         dmat->bounce_flags |=
 351                                             BUS_DMA_MIN_ALLOC_COMP;
 352                                 }
 353                         } else
 354                                 error = 0;
 355                 }
 356                 bz->map_count++;
 357         } else {
 358                 *mapp = NULL;
 359         }
 360         if (error == 0)
 361                 dmat->map_count++;
 362         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 363             __func__, dmat, dmat->common.flags, error);
 364         return (error);
 365 }
 366
 367 /*
 368  * Destroy a handle for mapping from kva/uva/physical
 369  * address space into bus device space.
 370  */
 371 static int
 372 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 373 {
 374
 375         if (map != NULL && map != &nobounce_dmamap) {
 376                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 377                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 378                             __func__, dmat, EBUSY);
 379                         return (EBUSY);
 380                 }
 381                 if (dmat->bounce_zone)
 382                         dmat->bounce_zone->map_count--;
 383                 free_domain(map, M_DEVBUF);
 384         }
 385         dmat->map_count--;
 386         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 387         return (0);
 388 }
 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  * A dmamap to for use with dmamap_load is also allocated.
 395  */
 396 static int
 397 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 398     bus_dmamap_t *mapp)
 399 {
 400         vm_memattr_t attr;
 401         int mflags;
 402
 403         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
 404
 405         if (flags & BUS_DMA_NOWAIT)
 406                 mflags = M_NOWAIT;
 407         else
 408                 mflags = M_WAITOK;
 409
 410         /* If we succeed, no mapping/bouncing will be required */
 411         *mapp = NULL;
 412
 413         if (dmat->segments == NULL) {
 414                 dmat->segments = (bus_dma_segment_t *)malloc_domain(
 415                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 416                     M_DEVBUF, dmat->common.domain, mflags);
 417                 if (dmat->segments == NULL) {
 418                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 419                             __func__, dmat, dmat->common.flags, ENOMEM);
 420                         return (ENOMEM);
 421                 }
 422         }
 423         if (flags & BUS_DMA_ZERO)
 424                 mflags |= M_ZERO;
 425         if (flags & BUS_DMA_NOCACHE)
 426                 attr = VM_MEMATTR_UNCACHEABLE;
 427         else
 428                 attr = VM_MEMATTR_DEFAULT;
 429
 430         /*
 431          * Allocate the buffer from the malloc(9) allocator if...
 432          *  - It's small enough to fit into a single power of two sized bucket.
 433          *  - The alignment is less than or equal to the maximum size
 434          *  - The low address requirement is fulfilled.
 435          * else allocate non-contiguous pages if...
 436          *  - The page count that could get allocated doesn't exceed
 437          *    nsegments also when the maximum segment size is less
 438          *    than PAGE_SIZE.
 439          *  - The alignment constraint isn't larger than a page boundary.
 440          *  - There are no boundary-crossing constraints.
 441          * else allocate a block of contiguous pages because one or more of the
 442          * constraints is something that only the contig allocator can fulfill.
 443          *
 444          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 445          * below is just a quick hack. The exact alignment guarantees
 446          * of malloc(9) need to be nailed down, and the code below
 447          * should be rewritten to take that into account.
 448          *
 449          * In the meantime warn the user if malloc gets it wrong.
 450          */
 451         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 452            (dmat->common.alignment <= dmat->common.maxsize) &&
 453             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 454             attr == VM_MEMATTR_DEFAULT) {
 455                 *vaddr = malloc_domain(dmat->common.maxsize, M_DEVBUF,
 456                     dmat->common.domain, mflags);
 457         } else if (dmat->common.nsegments >=
 458             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
 459             dmat->common.alignment <= PAGE_SIZE &&
 460             (dmat->common.boundary % PAGE_SIZE) == 0) {
 461                 /* Page-based multi-segment allocations allowed */
 462                 *vaddr = (void *)kmem_alloc_attr_domain(dmat->common.domain,
 463                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 464                     attr);
 465                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 466         } else {
 467                 *vaddr = (void *)kmem_alloc_contig_domain(dmat->common.domain,
 468                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 469                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 470                     dmat->common.boundary, attr);
 471                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 472         }
 473         if (*vaddr == NULL) {
 474                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 475                     __func__, dmat, dmat->common.flags, ENOMEM);
 476                 return (ENOMEM);
 477         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 478                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 479         }
 480         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 481             __func__, dmat, dmat->common.flags, 0);
 482         return (0);
 483 }
 484
 485 /*
 486  * Free a piece of memory and it's allociated dmamap, that was allocated
 487  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 488  */
 489 static void
 490 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 491 {
 492         /*
 493          * dmamem does not need to be bounced, so the map should be
 494          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 495          * was used and set if kmem_alloc_contig() was used.
 496          */
 497         if (map != NULL)
 498                 panic("bus_dmamem_free: Invalid map freed\n");
 499         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 500                 free_domain(vaddr, M_DEVBUF);
 501         else
 502                 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 503         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 504             dmat->bounce_flags);
 505 }
 506
 507 static void
 508 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 509     bus_size_t buflen, int flags)
 510 {
 511         bus_addr_t curaddr;
 512         bus_size_t sgsize;
 513
 514         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 515                 /*
 516                  * Count the number of bounce pages
 517                  * needed in order to complete this transfer
 518                  */
 519                 curaddr = buf;
 520                 while (buflen != 0) {
 521                         sgsize = MIN(buflen, dmat->common.maxsegsz);
 522                         if (bus_dma_run_filter(&dmat->common, curaddr)) {
 523                                 sgsize = MIN(sgsize,
 524                                     PAGE_SIZE - (curaddr & PAGE_MASK));
 525                                 map->pagesneeded++;
 526                         }
 527                         curaddr += sgsize;
 528                         buflen -= sgsize;
 529                 }
 530                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 531         }
 532 }
 533
 534 static void
 535 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 536     void *buf, bus_size_t buflen, int flags)
 537 {
 538         vm_offset_t vaddr;
 539         vm_offset_t vendaddr;
 540         bus_addr_t paddr;
 541         bus_size_t sg_len;
 542
 543         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 544                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 545                     "alignment= %d", dmat->common.lowaddr,
 546                     ptoa((vm_paddr_t)Maxmem),
 547                     dmat->common.boundary, dmat->common.alignment);
 548                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 549                     map, &nobounce_dmamap, map->pagesneeded);
 550                 /*
 551                  * Count the number of bounce pages
 552                  * needed in order to complete this transfer
 553                  */
 554                 vaddr = (vm_offset_t)buf;
 555                 vendaddr = (vm_offset_t)buf + buflen;
 556
 557                 while (vaddr < vendaddr) {
 558                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 559                         if (pmap == kernel_pmap)
 560                                 paddr = pmap_kextract(vaddr);
 561                         else
 562                                 paddr = pmap_extract(pmap, vaddr);
 563                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 564                                 sg_len = roundup2(sg_len,
 565                                     dmat->common.alignment);
 566                                 map->pagesneeded++;
 567                         }
 568                         vaddr += sg_len;
 569                 }
 570                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 571         }
 572 }
 573
 574 static void
 575 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 576     int ma_offs, bus_size_t buflen, int flags)
 577 {
 578         bus_size_t sg_len, max_sgsize;
 579         int page_index;
 580         vm_paddr_t paddr;
 581
 582         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 583                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 584                     "alignment= %d", dmat->common.lowaddr,
 585                     ptoa((vm_paddr_t)Maxmem),
 586                     dmat->common.boundary, dmat->common.alignment);
 587                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 588                     map, &nobounce_dmamap, map->pagesneeded);
 589
 590                 /*
 591                  * Count the number of bounce pages
 592                  * needed in order to complete this transfer
 593                  */
 594                 page_index = 0;
 595                 while (buflen > 0) {
 596                         paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 597                         sg_len = PAGE_SIZE - ma_offs;
 598                         max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 599                         sg_len = MIN(sg_len, max_sgsize);
 600                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 601                                 sg_len = roundup2(sg_len,
 602                                     dmat->common.alignment);
 603                                 sg_len = MIN(sg_len, max_sgsize);
 604                                 KASSERT((sg_len & (dmat->common.alignment - 1))
 605                                     == 0, ("Segment size is not aligned"));
 606                                 map->pagesneeded++;
 607                         }
 608                         if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
 609                                 page_index++;
 610                         ma_offs = (ma_offs + sg_len) & PAGE_MASK;
 611                         KASSERT(buflen >= sg_len,
 612                             ("Segment length overruns original buffer"));
 613                         buflen -= sg_len;
 614                 }
 615                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 616         }
 617 }
 618
 619 static int
 620 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 621 {
 622
 623         /* Reserve Necessary Bounce Pages */
 624         mtx_lock(&bounce_lock);
 625         if (flags & BUS_DMA_NOWAIT) {
 626                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 627                         mtx_unlock(&bounce_lock);
 628                         return (ENOMEM);
 629                 }
 630         } else {
 631                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 632                         /* Queue us for resources */
 633                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 634                         mtx_unlock(&bounce_lock);
 635                         return (EINPROGRESS);
 636                 }
 637         }
 638         mtx_unlock(&bounce_lock);
 639
 640         return (0);
 641 }
 642
 643 /*
 644  * Add a single contiguous physical range to the segment list.
 645  */
 646 static int
 647 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 648     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 649 {
 650         bus_addr_t baddr, bmask;
 651         int seg;
 652
 653         /*
 654          * Make sure we don't cross any boundaries.
 655          */
 656         bmask = ~(dmat->common.boundary - 1);
 657         if (dmat->common.boundary > 0) {
 658                 baddr = (curaddr + dmat->common.boundary) & bmask;
 659                 if (sgsize > (baddr - curaddr))
 660                         sgsize = (baddr - curaddr);
 661         }
 662
 663         /*
 664          * Insert chunk into a segment, coalescing with
 665          * previous segment if possible.
 666          */
 667         seg = *segp;
 668         if (seg == -1) {
 669                 seg = 0;
 670                 segs[seg].ds_addr = curaddr;
 671                 segs[seg].ds_len = sgsize;
 672         } else {
 673                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 674                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 675                     (dmat->common.boundary == 0 ||
 676                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 677                         segs[seg].ds_len += sgsize;
 678                 else {
 679                         if (++seg >= dmat->common.nsegments)
 680                                 return (0);
 681                         segs[seg].ds_addr = curaddr;
 682                         segs[seg].ds_len = sgsize;
 683                 }
 684         }
 685         *segp = seg;
 686         return (sgsize);
 687 }
 688
 689 /*
 690  * Utility function to load a physical buffer.  segp contains
 691  * the starting segment on entrace, and the ending segment on exit.
 692  */
 693 static int
 694 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 695     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 696     int *segp)
 697 {
 698         bus_size_t sgsize;
 699         bus_addr_t curaddr;
 700         int error;
 701
 702         if (map == NULL)
 703                 map = &nobounce_dmamap;
 704
 705         if (segs == NULL)
 706                 segs = dmat->segments;
 707
 708         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 709                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 710                 if (map->pagesneeded != 0) {
 711                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 712                         if (error)
 713                                 return (error);
 714                 }
 715         }
 716
 717         while (buflen > 0) {
 718                 curaddr = buf;
 719                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 720                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 721                     map->pagesneeded != 0 &&
 722                     bus_dma_run_filter(&dmat->common, curaddr)) {
 723                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 724                         curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
 725                             sgsize);
 726                 }
 727                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 728                     segp);
 729                 if (sgsize == 0)
 730                         break;
 731                 buf += sgsize;
 732                 buflen -= sgsize;
 733         }
 734
 735         /*
 736          * Did we fit?
 737          */
 738         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 739 }
 740
 741 /*
 742  * Utility function to load a linear buffer.  segp contains
 743  * the starting segment on entrace, and the ending segment on exit.
 744  */
 745 static int
 746 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 747     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 748     int *segp)
 749 {
 750         bus_size_t sgsize, max_sgsize;
 751         bus_addr_t curaddr;
 752         vm_offset_t kvaddr, vaddr;
 753         int error;
 754
 755         if (map == NULL)
 756                 map = &nobounce_dmamap;
 757
 758         if (segs == NULL)
 759                 segs = dmat->segments;
 760
 761         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 762                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 763                 if (map->pagesneeded != 0) {
 764                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 765                         if (error)
 766                                 return (error);
 767                 }
 768         }
 769
 770         vaddr = (vm_offset_t)buf;
 771         while (buflen > 0) {
 772                 /*
 773                  * Get the physical address for this segment.
 774                  */
 775                 if (pmap == kernel_pmap) {
 776                         curaddr = pmap_kextract(vaddr);
 777                         kvaddr = vaddr;
 778                 } else {
 779                         curaddr = pmap_extract(pmap, vaddr);
 780                         kvaddr = 0;
 781                 }
 782
 783                 /*
 784                  * Compute the segment size, and adjust counts.
 785                  */
 786                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 787                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 788                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 789                     map->pagesneeded != 0 &&
 790                     bus_dma_run_filter(&dmat->common, curaddr)) {
 791                         sgsize = roundup2(sgsize, dmat->common.alignment);
 792                         sgsize = MIN(sgsize, max_sgsize);
 793                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 794                             sgsize);
 795                 } else {
 796                         sgsize = MIN(sgsize, max_sgsize);
 797                 }
 798                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 799                     segp);
 800                 if (sgsize == 0)
 801                         break;
 802                 vaddr += sgsize;
 803                 buflen -= sgsize;
 804         }
 805
 806         /*
 807          * Did we fit?
 808          */
 809         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 810 }
 811
 812 static int
 813 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 814     struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
 815     bus_dma_segment_t *segs, int *segp)
 816 {
 817         vm_paddr_t paddr, next_paddr;
 818         int error, page_index;
 819         bus_size_t sgsize, max_sgsize;
 820
 821         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 822                 /*
 823                  * If we have to keep the offset of each page this function
 824                  * is not suitable, switch back to bus_dmamap_load_ma_triv
 825                  * which is going to do the right thing in this case.
 826                  */
 827                 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
 828                     flags, segs, segp);
 829                 return (error);
 830         }
 831
 832         if (map == NULL)
 833                 map = &nobounce_dmamap;
 834
 835         if (segs == NULL)
 836                 segs = dmat->segments;
 837
 838         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 839                 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
 840                 if (map->pagesneeded != 0) {
 841                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 842                         if (error)
 843                                 return (error);
 844                 }
 845         }
 846
 847         page_index = 0;
 848         while (buflen > 0) {
 849                 /*
 850                  * Compute the segment size, and adjust counts.
 851                  */
 852                 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 853                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 854                 sgsize = PAGE_SIZE - ma_offs;
 855                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 856                     map->pagesneeded != 0 &&
 857                     bus_dma_run_filter(&dmat->common, paddr)) {
 858                         sgsize = roundup2(sgsize, dmat->common.alignment);
 859                         sgsize = MIN(sgsize, max_sgsize);
 860                         KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
 861                             ("Segment size is not aligned"));
 862                         /*
 863                          * Check if two pages of the user provided buffer
 864                          * are used.
 865                          */
 866                         if ((ma_offs + sgsize) > PAGE_SIZE)
 867                                 next_paddr =
 868                                     VM_PAGE_TO_PHYS(ma[page_index + 1]);
 869                         else
 870                                 next_paddr = 0;
 871                         paddr = add_bounce_page(dmat, map, 0, paddr,
 872                             next_paddr, sgsize);
 873                 } else {
 874                         sgsize = MIN(sgsize, max_sgsize);
 875                 }
 876                 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
 877                     segp);
 878                 if (sgsize == 0)
 879                         break;
 880                 KASSERT(buflen >= sgsize,
 881                     ("Segment length overruns original buffer"));
 882                 buflen -= sgsize;
 883                 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
 884                         page_index++;
 885                 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
 886         }
 887
 888         /*
 889          * Did we fit?
 890          */
 891         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 892 }
 893
 894 static void
 895 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 896     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 897 {
 898
 899         if (map == NULL)
 900                 return;
 901         map->mem = *mem;
 902         map->dmat = dmat;
 903         map->callback = callback;
 904         map->callback_arg = callback_arg;
 905 }
 906
 907 static bus_dma_segment_t *
 908 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 909     bus_dma_segment_t *segs, int nsegs, int error)
 910 {
 911
 912         if (segs == NULL)
 913                 segs = dmat->segments;
 914         return (segs);
 915 }
 916
 917 /*
 918  * Release the mapping held by map.
 919  */
 920 static void
 921 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 922 {
 923         struct bounce_page *bpage;
 924
 925         if (map == NULL)
 926                 return;
 927
 928         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 929                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 930                 free_bounce_page(dmat, bpage);
 931         }
 932 }
 933
 934 static void
 935 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 936     bus_dmasync_op_t op)
 937 {
 938         struct bounce_page *bpage;
 939         vm_offset_t datavaddr, tempvaddr;
 940         bus_size_t datacount1, datacount2;
 941
 942         if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 943                 return;
 944
 945         /*
 946          * Handle data bouncing.  We might also want to add support for
 947          * invalidating the caches on broken hardware.
 948          */
 949         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 950             "performing bounce", __func__, dmat, dmat->common.flags, op);
 951
 952         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 953                 while (bpage != NULL) {
 954                         tempvaddr = 0;
 955                         datavaddr = bpage->datavaddr;
 956                         datacount1 = bpage->datacount;
 957                         if (datavaddr == 0) {
 958                                 tempvaddr =
 959                                     pmap_quick_enter_page(bpage->datapage[0]);
 960                                 datavaddr = tempvaddr | bpage->dataoffs;
 961                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 962                                     datacount1);
 963                         }
 964
 965                         bcopy((void *)datavaddr,
 966                             (void *)bpage->vaddr, datacount1);
 967
 968                         if (tempvaddr != 0)
 969                                 pmap_quick_remove_page(tempvaddr);
 970
 971                         if (bpage->datapage[1] == 0) {
 972                                 KASSERT(datacount1 == bpage->datacount,
 973                 ("Mismatch between data size and provided memory space"));
 974                                 goto next_w;
 975                         }
 976
 977                         /*
 978                          * We are dealing with an unmapped buffer that expands
 979                          * over two pages.
 980                          */
 981                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
 982                         datacount2 = bpage->datacount - datacount1;
 983                         bcopy((void *)datavaddr,
 984                             (void *)(bpage->vaddr + datacount1), datacount2);
 985                         pmap_quick_remove_page(datavaddr);
 986
 987 next_w:
 988                         bpage = STAILQ_NEXT(bpage, links);
 989                 }
 990                 dmat->bounce_zone->total_bounced++;
 991         }
 992
 993         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
 994                 while (bpage != NULL) {
 995                         tempvaddr = 0;
 996                         datavaddr = bpage->datavaddr;
 997                         datacount1 = bpage->datacount;
 998                         if (datavaddr == 0) {
 999                                 tempvaddr =
1000                                     pmap_quick_enter_page(bpage->datapage[0]);
1001                                 datavaddr = tempvaddr | bpage->dataoffs;
1002                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
1003                                     datacount1);
1004                         }
1005
1006                         bcopy((void *)bpage->vaddr, (void *)datavaddr,
1007                             datacount1);
1008
1009                         if (tempvaddr != 0)
1010                                 pmap_quick_remove_page(tempvaddr);
1011
1012                         if (bpage->datapage[1] == 0) {
1013                                 KASSERT(datacount1 == bpage->datacount,
1014                 ("Mismatch between data size and provided memory space"));
1015                                 goto next_r;
1016                         }
1017
1018                         /*
1019                          * We are dealing with an unmapped buffer that expands
1020                          * over two pages.
1021                          */
1022                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1023                         datacount2 = bpage->datacount - datacount1;
1024                         bcopy((void *)(bpage->vaddr + datacount1),
1025                             (void *)datavaddr, datacount2);
1026                         pmap_quick_remove_page(datavaddr);
1027
1028 next_r:
1029                         bpage = STAILQ_NEXT(bpage, links);
1030                 }
1031                 dmat->bounce_zone->total_bounced++;
1032         }
1033 }
1034
1035 static void
1036 init_bounce_pages(void *dummy __unused)
1037 {
1038
1039         total_bpages = 0;
1040         STAILQ_INIT(&bounce_zone_list);
1041         STAILQ_INIT(&bounce_map_waitinglist);
1042         STAILQ_INIT(&bounce_map_callbacklist);
1043         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1044 }
1045 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1046
1047 static struct sysctl_ctx_list *
1048 busdma_sysctl_tree(struct bounce_zone *bz)
1049 {
1050
1051         return (&bz->sysctl_tree);
1052 }
1053
1054 static struct sysctl_oid *
1055 busdma_sysctl_tree_top(struct bounce_zone *bz)
1056 {
1057
1058         return (bz->sysctl_tree_top);
1059 }
1060
1061 static int
1062 alloc_bounce_zone(bus_dma_tag_t dmat)
1063 {
1064         struct bounce_zone *bz;
1065
1066         /* Check to see if we already have a suitable zone */
1067         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1068                 if ((dmat->common.alignment <= bz->alignment) &&
1069                     (dmat->common.lowaddr >= bz->lowaddr) &&
1070                     (dmat->common.domain == bz->domain)) {
1071                         dmat->bounce_zone = bz;
1072                         return (0);
1073                 }
1074         }
1075
1076         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1077             M_NOWAIT | M_ZERO)) == NULL)
1078                 return (ENOMEM);
1079
1080         STAILQ_INIT(&bz->bounce_page_list);
1081         bz->free_bpages = 0;
1082         bz->reserved_bpages = 0;
1083         bz->active_bpages = 0;
1084         bz->lowaddr = dmat->common.lowaddr;
1085         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1086         bz->map_count = 0;
1087         bz->domain = dmat->common.domain;
1088         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1089         busdma_zonecount++;
1090         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1091         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1092         dmat->bounce_zone = bz;
1093
1094         sysctl_ctx_init(&bz->sysctl_tree);
1095         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1096             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1097             CTLFLAG_RD, 0, "");
1098         if (bz->sysctl_tree_top == NULL) {
1099                 sysctl_ctx_free(&bz->sysctl_tree);
1100                 return (0);     /* XXX error code? */
1101         }
1102
1103         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1104             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1105             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1106             "Total bounce pages");
1107         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1108             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1109             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1110             "Free bounce pages");
1111         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1112             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1113             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1114             "Reserved bounce pages");
1115         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1116             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1117             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1118             "Active bounce pages");
1119         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1120             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1121             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1122             "Total bounce requests");
1123         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1124             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1125             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1126             "Total bounce requests that were deferred");
1127         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1128             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1129             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1130         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1131             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1132             "alignment", CTLFLAG_RD, &bz->alignment, "");
1133         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1134             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1135             "domain", CTLFLAG_RD, &bz->domain, 0,
1136             "memory domain");
1137
1138         return (0);
1139 }
1140
1141 static int
1142 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1143 {
1144         struct bounce_zone *bz;
1145         int count;
1146
1147         bz = dmat->bounce_zone;
1148         count = 0;
1149         while (numpages > 0) {
1150                 struct bounce_page *bpage;
1151
1152                 bpage = (struct bounce_page *)malloc_domain(sizeof(*bpage),
1153                     M_DEVBUF, dmat->common.domain, M_NOWAIT | M_ZERO);
1154
1155                 if (bpage == NULL)
1156                         break;
1157                 bpage->vaddr = (vm_offset_t)contigmalloc_domain(PAGE_SIZE,
1158                     M_DEVBUF, dmat->common.domain, M_NOWAIT, 0ul,
1159                     bz->lowaddr, PAGE_SIZE, 0);
1160                 if (bpage->vaddr == 0) {
1161                         free_domain(bpage, M_DEVBUF);
1162                         break;
1163                 }
1164                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1165                 mtx_lock(&bounce_lock);
1166                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1167                 total_bpages++;
1168                 bz->total_bpages++;
1169                 bz->free_bpages++;
1170                 mtx_unlock(&bounce_lock);
1171                 count++;
1172                 numpages--;
1173         }
1174         return (count);
1175 }
1176
1177 static int
1178 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1179 {
1180         struct bounce_zone *bz;
1181         int pages;
1182
1183         mtx_assert(&bounce_lock, MA_OWNED);
1184         bz = dmat->bounce_zone;
1185         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1186         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1187                 return (map->pagesneeded - (map->pagesreserved + pages));
1188         bz->free_bpages -= pages;
1189         bz->reserved_bpages += pages;
1190         map->pagesreserved += pages;
1191         pages = map->pagesneeded - map->pagesreserved;
1192
1193         return (pages);
1194 }
1195
1196 static bus_addr_t
1197 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1198                 bus_addr_t addr1, bus_addr_t addr2, bus_size_t size)
1199 {
1200         struct bounce_zone *bz;
1201         struct bounce_page *bpage;
1202
1203         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1204         KASSERT(map != NULL && map != &nobounce_dmamap,
1205             ("add_bounce_page: bad map %p", map));
1206
1207         bz = dmat->bounce_zone;
1208         if (map->pagesneeded == 0)
1209                 panic("add_bounce_page: map doesn't need any pages");
1210         map->pagesneeded--;
1211
1212         if (map->pagesreserved == 0)
1213                 panic("add_bounce_page: map doesn't need any pages");
1214         map->pagesreserved--;
1215
1216         mtx_lock(&bounce_lock);
1217         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1218         if (bpage == NULL)
1219                 panic("add_bounce_page: free page list is empty");
1220
1221         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1222         bz->reserved_bpages--;
1223         bz->active_bpages++;
1224         mtx_unlock(&bounce_lock);
1225
1226         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1227                 /* Page offset needs to be preserved. */
1228                 bpage->vaddr |= addr1 & PAGE_MASK;
1229                 bpage->busaddr |= addr1 & PAGE_MASK;
1230                 KASSERT(addr2 == 0,
1231         ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1232         }
1233         bpage->datavaddr = vaddr;
1234         bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1235         KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1236         bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1237         bpage->dataoffs = addr1 & PAGE_MASK;
1238         bpage->datacount = size;
1239         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1240         return (bpage->busaddr);
1241 }
1242
1243 static void
1244 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1245 {
1246         struct bus_dmamap *map;
1247         struct bounce_zone *bz;
1248
1249         bz = dmat->bounce_zone;
1250         bpage->datavaddr = 0;
1251         bpage->datacount = 0;
1252         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1253                 /*
1254                  * Reset the bounce page to start at offset 0.  Other uses
1255                  * of this bounce page may need to store a full page of
1256                  * data and/or assume it starts on a page boundary.
1257                  */
1258                 bpage->vaddr &= ~PAGE_MASK;
1259                 bpage->busaddr &= ~PAGE_MASK;
1260         }
1261
1262         mtx_lock(&bounce_lock);
1263         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1264         bz->free_bpages++;
1265         bz->active_bpages--;
1266         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1267                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1268                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1269                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1270                             map, links);
1271                         busdma_swi_pending = 1;
1272                         bz->total_deferred++;
1273                         swi_sched(vm_ih, 0);
1274                 }
1275         }
1276         mtx_unlock(&bounce_lock);
1277 }
1278
1279 void
1280 busdma_swi(void)
1281 {
1282         bus_dma_tag_t dmat;
1283         struct bus_dmamap *map;
1284
1285         mtx_lock(&bounce_lock);
1286         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1287                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1288                 mtx_unlock(&bounce_lock);
1289                 dmat = map->dmat;
1290                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1291                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1292                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1293                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1294                     BUS_DMA_UNLOCK);
1295                 mtx_lock(&bounce_lock);
1296         }
1297         mtx_unlock(&bounce_lock);
1298 }
1299
1300 struct bus_dma_impl bus_dma_bounce_impl = {
1301         .tag_create = bounce_bus_dma_tag_create,
1302         .tag_destroy = bounce_bus_dma_tag_destroy,
1303         .tag_set_domain = bounce_bus_dma_tag_set_domain,
1304         .map_create = bounce_bus_dmamap_create,
1305         .map_destroy = bounce_bus_dmamap_destroy,
1306         .mem_alloc = bounce_bus_dmamem_alloc,
1307         .mem_free = bounce_bus_dmamem_free,
1308         .load_phys = bounce_bus_dmamap_load_phys,
1309         .load_buffer = bounce_bus_dmamap_load_buffer,
1310         .load_ma = bounce_bus_dmamap_load_ma,
1311         .map_waitok = bounce_bus_dmamap_waitok,
1312         .map_complete = bounce_bus_dmamap_complete,
1313         .map_unload = bounce_bus_dmamap_unload,
1314         .map_sync = bounce_bus_dmamap_sync,
1315 };