sys/arm64/arm64/busdma_bounce.c

   1 /*-
   2  * Copyright (c) 1997, 1998 Justin T. Gibbs.
   3  * Copyright (c) 2015-2016 The FreeBSD Foundation
   4  * All rights reserved.
   5  *
   6  * Portions of this software were developed by Andrew Turner
   7  * under sponsorship of the FreeBSD Foundation.
   8  *
   9  * Portions of this software were developed by Semihalf
  10  * under sponsorship of the FreeBSD Foundation.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions, and the following disclaimer,
  17  *    without modification, immediately at the beginning of the file.
  18  * 2. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  25  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/malloc.h>
  40 #include <sys/bus.h>
  41 #include <sys/interrupt.h>
  42 #include <sys/kernel.h>
  43 #include <sys/ktr.h>
  44 #include <sys/lock.h>
  45 #include <sys/proc.h>
  46 #include <sys/memdesc.h>
  47 #include <sys/mutex.h>
  48 #include <sys/sysctl.h>
  49 #include <sys/uio.h>
  50
  51 #include <vm/vm.h>
  52 #include <vm/vm_extern.h>
  53 #include <vm/vm_kern.h>
  54 #include <vm/vm_page.h>
  55 #include <vm/vm_map.h>
  56
  57 #include <machine/atomic.h>
  58 #include <machine/bus.h>
  59 #include <machine/md_var.h>
  60 #include <arm64/include/bus_dma_impl.h>
  61
  62 #define MAX_BPAGES 4096
  63
  64 enum {
  65         BF_COULD_BOUNCE         = 0x01,
  66         BF_MIN_ALLOC_COMP       = 0x02,
  67         BF_KMEM_ALLOC           = 0x04,
  68         BF_COHERENT             = 0x10,
  69 };
  70
  71 struct bounce_zone;
  72
  73 struct bus_dma_tag {
  74         struct bus_dma_tag_common common;
  75         int                     map_count;
  76         int                     bounce_flags;
  77         bus_dma_segment_t       *segments;
  78         struct bounce_zone      *bounce_zone;
  79 };
  80
  81 struct bounce_page {
  82         vm_offset_t     vaddr;          /* kva of bounce buffer */
  83         bus_addr_t      busaddr;        /* Physical address */
  84         vm_offset_t     datavaddr;      /* kva of client data */
  85         vm_page_t       datapage;       /* physical page of client data */
  86         vm_offset_t     dataoffs;       /* page offset of client data */
  87         bus_size_t      datacount;      /* client data count */
  88         STAILQ_ENTRY(bounce_page) links;
  89 };
  90
  91 int busdma_swi_pending;
  92
  93 struct bounce_zone {
  94         STAILQ_ENTRY(bounce_zone) links;
  95         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  96         int             total_bpages;
  97         int             free_bpages;
  98         int             reserved_bpages;
  99         int             active_bpages;
 100         int             total_bounced;
 101         int             total_deferred;
 102         int             map_count;
 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 | CTLFLAG_MPSAFE, 0,
 117     "Busdma parameters");
 118 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 119            "Total bounce pages");
 120
 121 struct sync_list {
 122         vm_offset_t     vaddr;          /* kva of client data */
 123         bus_addr_t      paddr;          /* physical address */
 124         vm_page_t       pages;          /* starting page of client data */
 125         bus_size_t      datacount;      /* client data count */
 126 };
 127
 128 struct bus_dmamap {
 129         struct bp_list         bpages;
 130         int                    pagesneeded;
 131         int                    pagesreserved;
 132         bus_dma_tag_t          dmat;
 133         struct memdesc         mem;
 134         bus_dmamap_callback_t *callback;
 135         void                  *callback_arg;
 136         STAILQ_ENTRY(bus_dmamap) links;
 137         u_int                   flags;
 138 #define DMAMAP_COULD_BOUNCE     (1 << 0)
 139 #define DMAMAP_FROM_DMAMEM      (1 << 1)
 140         int                     sync_count;
 141         struct sync_list        slist[];
 142 };
 143
 144 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 145 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 146
 147 static void init_bounce_pages(void *dummy);
 148 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 149 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 150 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 151     int commit);
 152 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 153     vm_offset_t vaddr, bus_addr_t addr, bus_size_t size);
 154 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 155 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 156 static bool _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf,
 157     bus_size_t buflen, int *pagesneeded);
 158 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 159     pmap_t pmap, void *buf, bus_size_t buflen, int flags);
 160 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 161     vm_paddr_t buf, bus_size_t buflen, int flags);
 162 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 163     int flags);
 164
 165 /*
 166  * Allocate a device specific dma_tag.
 167  */
 168 static int
 169 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 170     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 171     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 172     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 173     void *lockfuncarg, bus_dma_tag_t *dmat)
 174 {
 175         bus_dma_tag_t newtag;
 176         int error;
 177
 178         *dmat = NULL;
 179         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 180             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 181             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 182             sizeof (struct bus_dma_tag), (void **)&newtag);
 183         if (error != 0)
 184                 return (error);
 185
 186         newtag->common.impl = &bus_dma_bounce_impl;
 187         newtag->map_count = 0;
 188         newtag->segments = NULL;
 189
 190         if ((flags & BUS_DMA_COHERENT) != 0)
 191                 newtag->bounce_flags |= BF_COHERENT;
 192
 193         if (parent != NULL) {
 194                 if ((newtag->common.filter != NULL ||
 195                     (parent->bounce_flags & BF_COULD_BOUNCE) != 0))
 196                         newtag->bounce_flags |= BF_COULD_BOUNCE;
 197
 198                 /* Copy some flags from the parent */
 199                 newtag->bounce_flags |= parent->bounce_flags & BF_COHERENT;
 200         }
 201
 202         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 203             newtag->common.alignment > 1)
 204                 newtag->bounce_flags |= BF_COULD_BOUNCE;
 205
 206         if (((newtag->bounce_flags & BF_COULD_BOUNCE) != 0) &&
 207             (flags & BUS_DMA_ALLOCNOW) != 0) {
 208                 struct bounce_zone *bz;
 209
 210                 /* Must bounce */
 211                 if ((error = alloc_bounce_zone(newtag)) != 0) {
 212                         free(newtag, M_DEVBUF);
 213                         return (error);
 214                 }
 215                 bz = newtag->bounce_zone;
 216
 217                 if (ptoa(bz->total_bpages) < maxsize) {
 218                         int pages;
 219
 220                         pages = atop(round_page(maxsize)) - bz->total_bpages;
 221
 222                         /* Add pages to our bounce pool */
 223                         if (alloc_bounce_pages(newtag, pages) < pages)
 224                                 error = ENOMEM;
 225                 }
 226                 /* Performed initial allocation */
 227                 newtag->bounce_flags |= BF_MIN_ALLOC_COMP;
 228         } else
 229                 error = 0;
 230
 231         if (error != 0)
 232                 free(newtag, M_DEVBUF);
 233         else
 234                 *dmat = newtag;
 235         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 236             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 237             error);
 238         return (error);
 239 }
 240
 241 static int
 242 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 243 {
 244         bus_dma_tag_t dmat_copy, parent;
 245         int error;
 246
 247         error = 0;
 248         dmat_copy = dmat;
 249
 250         if (dmat != NULL) {
 251                 if (dmat->map_count != 0) {
 252                         error = EBUSY;
 253                         goto out;
 254                 }
 255                 while (dmat != NULL) {
 256                         parent = (bus_dma_tag_t)dmat->common.parent;
 257                         atomic_subtract_int(&dmat->common.ref_count, 1);
 258                         if (dmat->common.ref_count == 0) {
 259                                 if (dmat->segments != NULL)
 260                                         free(dmat->segments, M_DEVBUF);
 261                                 free(dmat, M_DEVBUF);
 262                                 /*
 263                                  * Last reference count, so
 264                                  * release our reference
 265                                  * count on our parent.
 266                                  */
 267                                 dmat = parent;
 268                         } else
 269                                 dmat = NULL;
 270                 }
 271         }
 272 out:
 273         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 274         return (error);
 275 }
 276
 277 static bool
 278 bounce_bus_dma_id_mapped(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen)
 279 {
 280
 281         if ((dmat->bounce_flags & BF_COULD_BOUNCE) == 0)
 282                 return (true);
 283         return (!_bus_dmamap_pagesneeded(dmat, buf, buflen, NULL));
 284 }
 285
 286 static bus_dmamap_t
 287 alloc_dmamap(bus_dma_tag_t dmat, int flags)
 288 {
 289         u_long mapsize;
 290         bus_dmamap_t map;
 291
 292         mapsize = sizeof(*map);
 293         mapsize += sizeof(struct sync_list) * dmat->common.nsegments;
 294         map = malloc(mapsize, M_DEVBUF, flags | M_ZERO);
 295         if (map == NULL)
 296                 return (NULL);
 297
 298         /* Initialize the new map */
 299         STAILQ_INIT(&map->bpages);
 300
 301         return (map);
 302 }
 303
 304 /*
 305  * Allocate a handle for mapping from kva/uva/physical
 306  * address space into bus device space.
 307  */
 308 static int
 309 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 310 {
 311         struct bounce_zone *bz;
 312         int error, maxpages, pages;
 313
 314         error = 0;
 315
 316         if (dmat->segments == NULL) {
 317                 dmat->segments = (bus_dma_segment_t *)malloc(
 318                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 319                     M_DEVBUF, M_NOWAIT);
 320                 if (dmat->segments == NULL) {
 321                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 322                             __func__, dmat, ENOMEM);
 323                         return (ENOMEM);
 324                 }
 325         }
 326
 327         *mapp = alloc_dmamap(dmat, M_NOWAIT);
 328         if (*mapp == NULL) {
 329                 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 330                     __func__, dmat, ENOMEM);
 331                 return (ENOMEM);
 332         }
 333
 334         /*
 335          * Bouncing might be required if the driver asks for an active
 336          * exclusion region, a data alignment that is stricter than 1, and/or
 337          * an active address boundary.
 338          */
 339         if (dmat->bounce_flags & BF_COULD_BOUNCE) {
 340                 /* Must bounce */
 341                 if (dmat->bounce_zone == NULL) {
 342                         if ((error = alloc_bounce_zone(dmat)) != 0) {
 343                                 free(*mapp, M_DEVBUF);
 344                                 return (error);
 345                         }
 346                 }
 347                 bz = dmat->bounce_zone;
 348
 349                 (*mapp)->flags = DMAMAP_COULD_BOUNCE;
 350
 351                 /*
 352                  * Attempt to add pages to our pool on a per-instance
 353                  * basis up to a sane limit.
 354                  */
 355                 if (dmat->common.alignment > 1)
 356                         maxpages = MAX_BPAGES;
 357                 else
 358                         maxpages = MIN(MAX_BPAGES, Maxmem -
 359                             atop(dmat->common.lowaddr));
 360                 if ((dmat->bounce_flags & BF_MIN_ALLOC_COMP) == 0 ||
 361                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 362                         pages = MAX(atop(dmat->common.maxsize), 1);
 363                         pages = MIN(maxpages - bz->total_bpages, pages);
 364                         pages = MAX(pages, 1);
 365                         if (alloc_bounce_pages(dmat, pages) < pages)
 366                                 error = ENOMEM;
 367                         if ((dmat->bounce_flags & BF_MIN_ALLOC_COMP)
 368                             == 0) {
 369                                 if (error == 0) {
 370                                         dmat->bounce_flags |=
 371                                             BF_MIN_ALLOC_COMP;
 372                                 }
 373                         } else
 374                                 error = 0;
 375                 }
 376                 bz->map_count++;
 377         }
 378         if (error == 0)
 379                 dmat->map_count++;
 380         else
 381                 free(*mapp, M_DEVBUF);
 382         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 383             __func__, dmat, dmat->common.flags, error);
 384         return (error);
 385 }
 386
 387 /*
 388  * Destroy a handle for mapping from kva/uva/physical
 389  * address space into bus device space.
 390  */
 391 static int
 392 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 393 {
 394
 395         /* Check we are destroying the correct map type */
 396         if ((map->flags & DMAMAP_FROM_DMAMEM) != 0)
 397                 panic("bounce_bus_dmamap_destroy: Invalid map freed\n");
 398
 399         if (STAILQ_FIRST(&map->bpages) != NULL || map->sync_count != 0) {
 400                 CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, EBUSY);
 401                 return (EBUSY);
 402         }
 403         if (dmat->bounce_zone) {
 404                 KASSERT((map->flags & DMAMAP_COULD_BOUNCE) != 0,
 405                     ("%s: Bounce zone when cannot bounce", __func__));
 406                 dmat->bounce_zone->map_count--;
 407         }
 408         free(map, M_DEVBUF);
 409         dmat->map_count--;
 410         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 411         return (0);
 412 }
 413
 414 /*
 415  * Allocate a piece of memory that can be efficiently mapped into
 416  * bus device space based on the constraints lited in the dma tag.
 417  * A dmamap to for use with dmamap_load is also allocated.
 418  */
 419 static int
 420 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 421     bus_dmamap_t *mapp)
 422 {
 423         /*
 424          * XXX ARM64TODO:
 425          * This bus_dma implementation requires IO-Coherent architecutre.
 426          * If IO-Coherency is not guaranteed, the BUS_DMA_COHERENT flag has
 427          * to be implented using non-cacheable memory.
 428          */
 429
 430         vm_memattr_t attr;
 431         int mflags;
 432
 433         if (flags & BUS_DMA_NOWAIT)
 434                 mflags = M_NOWAIT;
 435         else
 436                 mflags = M_WAITOK;
 437
 438         if (dmat->segments == NULL) {
 439                 dmat->segments = (bus_dma_segment_t *)malloc(
 440                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 441                     M_DEVBUF, mflags);
 442                 if (dmat->segments == NULL) {
 443                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 444                             __func__, dmat, dmat->common.flags, ENOMEM);
 445                         return (ENOMEM);
 446                 }
 447         }
 448         if (flags & BUS_DMA_ZERO)
 449                 mflags |= M_ZERO;
 450         if (flags & BUS_DMA_NOCACHE)
 451                 attr = VM_MEMATTR_UNCACHEABLE;
 452         else if ((flags & BUS_DMA_COHERENT) != 0 &&
 453             (dmat->bounce_flags & BF_COHERENT) == 0)
 454                 /*
 455                  * If we have a non-coherent tag, and are trying to allocate
 456                  * a coherent block of memory it needs to be uncached.
 457                  */
 458                 attr = VM_MEMATTR_UNCACHEABLE;
 459         else
 460                 attr = VM_MEMATTR_DEFAULT;
 461
 462         /*
 463          * Create the map, but don't set the could bounce flag as
 464          * this allocation should never bounce;
 465          */
 466         *mapp = alloc_dmamap(dmat, mflags);
 467         if (*mapp == NULL) {
 468                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 469                     __func__, dmat, dmat->common.flags, ENOMEM);
 470                 return (ENOMEM);
 471         }
 472         (*mapp)->flags = DMAMAP_FROM_DMAMEM;
 473
 474         /*
 475          * Allocate the buffer from the malloc(9) allocator if...
 476          *  - It's small enough to fit into a single power of two sized bucket.
 477          *  - The alignment is less than or equal to the maximum size
 478          *  - The low address requirement is fulfilled.
 479          * else allocate non-contiguous pages if...
 480          *  - The page count that could get allocated doesn't exceed
 481          *    nsegments also when the maximum segment size is less
 482          *    than PAGE_SIZE.
 483          *  - The alignment constraint isn't larger than a page boundary.
 484          *  - There are no boundary-crossing constraints.
 485          * else allocate a block of contiguous pages because one or more of the
 486          * constraints is something that only the contig allocator can fulfill.
 487          *
 488          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 489          * below is just a quick hack. The exact alignment guarantees
 490          * of malloc(9) need to be nailed down, and the code below
 491          * should be rewritten to take that into account.
 492          *
 493          * In the meantime warn the user if malloc gets it wrong.
 494          */
 495         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 496            (dmat->common.alignment <= dmat->common.maxsize) &&
 497             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 498             attr == VM_MEMATTR_DEFAULT) {
 499                 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
 500         } else if (dmat->common.nsegments >=
 501             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
 502             dmat->common.alignment <= PAGE_SIZE &&
 503             (dmat->common.boundary % PAGE_SIZE) == 0) {
 504                 /* Page-based multi-segment allocations allowed */
 505                 *vaddr = (void *)kmem_alloc_attr(dmat->common.maxsize, mflags,
 506                     0ul, dmat->common.lowaddr, attr);
 507                 dmat->bounce_flags |= BF_KMEM_ALLOC;
 508         } else {
 509                 *vaddr = (void *)kmem_alloc_contig(dmat->common.maxsize, mflags,
 510                     0ul, dmat->common.lowaddr, dmat->common.alignment != 0 ?
 511                     dmat->common.alignment : 1ul, dmat->common.boundary, attr);
 512                 dmat->bounce_flags |= BF_KMEM_ALLOC;
 513         }
 514         if (*vaddr == NULL) {
 515                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 516                     __func__, dmat, dmat->common.flags, ENOMEM);
 517                 free(*mapp, M_DEVBUF);
 518                 return (ENOMEM);
 519         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 520                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 521         }
 522         dmat->map_count++;
 523         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 524             __func__, dmat, dmat->common.flags, 0);
 525         return (0);
 526 }
 527
 528 /*
 529  * Free a piece of memory and it's allociated dmamap, that was allocated
 530  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 531  */
 532 static void
 533 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 534 {
 535
 536         /*
 537          * Check the map came from bounce_bus_dmamem_alloc, so the map
 538          * should be NULL and the BF_KMEM_ALLOC flag cleared if malloc()
 539          * was used and set if kmem_alloc_contig() was used.
 540          */
 541         if ((map->flags & DMAMAP_FROM_DMAMEM) == 0)
 542                 panic("bus_dmamem_free: Invalid map freed\n");
 543         if ((dmat->bounce_flags & BF_KMEM_ALLOC) == 0)
 544                 free(vaddr, M_DEVBUF);
 545         else
 546                 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 547         free(map, M_DEVBUF);
 548         dmat->map_count--;
 549         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 550             dmat->bounce_flags);
 551 }
 552
 553 static bool
 554 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
 555     int *pagesneeded)
 556 {
 557         bus_addr_t curaddr;
 558         bus_size_t sgsize;
 559         int count;
 560
 561         /*
 562          * Count the number of bounce pages needed in order to
 563          * complete this transfer
 564          */
 565         count = 0;
 566         curaddr = buf;
 567         while (buflen != 0) {
 568                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 569                 if (bus_dma_run_filter(&dmat->common, curaddr)) {
 570                         sgsize = MIN(sgsize,
 571                             PAGE_SIZE - (curaddr & PAGE_MASK));
 572                         if (pagesneeded == NULL)
 573                                 return (true);
 574                         count++;
 575                 }
 576                 curaddr += sgsize;
 577                 buflen -= sgsize;
 578         }
 579
 580         if (pagesneeded != NULL)
 581                 *pagesneeded = count;
 582         return (count != 0);
 583 }
 584
 585 static void
 586 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 587     bus_size_t buflen, int flags)
 588 {
 589
 590         if ((map->flags & DMAMAP_COULD_BOUNCE) != 0 && map->pagesneeded == 0) {
 591                 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
 592                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 593         }
 594 }
 595
 596 static void
 597 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 598     void *buf, bus_size_t buflen, int flags)
 599 {
 600         vm_offset_t vaddr;
 601         vm_offset_t vendaddr;
 602         bus_addr_t paddr;
 603         bus_size_t sg_len;
 604
 605         if ((map->flags & DMAMAP_COULD_BOUNCE) != 0 && map->pagesneeded == 0) {
 606                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 607                     "alignment= %d", dmat->common.lowaddr,
 608                     ptoa((vm_paddr_t)Maxmem),
 609                     dmat->common.boundary, dmat->common.alignment);
 610                 CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d", map,
 611                     map->pagesneeded);
 612                 /*
 613                  * Count the number of bounce pages
 614                  * needed in order to complete this transfer
 615                  */
 616                 vaddr = (vm_offset_t)buf;
 617                 vendaddr = (vm_offset_t)buf + buflen;
 618
 619                 while (vaddr < vendaddr) {
 620                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 621                         if (pmap == kernel_pmap)
 622                                 paddr = pmap_kextract(vaddr);
 623                         else
 624                                 paddr = pmap_extract(pmap, vaddr);
 625                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 626                                 sg_len = roundup2(sg_len,
 627                                     dmat->common.alignment);
 628                                 map->pagesneeded++;
 629                         }
 630                         vaddr += sg_len;
 631                 }
 632                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 633         }
 634 }
 635
 636 static int
 637 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 638 {
 639
 640         /* Reserve Necessary Bounce Pages */
 641         mtx_lock(&bounce_lock);
 642         if (flags & BUS_DMA_NOWAIT) {
 643                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 644                         mtx_unlock(&bounce_lock);
 645                         return (ENOMEM);
 646                 }
 647         } else {
 648                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 649                         /* Queue us for resources */
 650                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 651                         mtx_unlock(&bounce_lock);
 652                         return (EINPROGRESS);
 653                 }
 654         }
 655         mtx_unlock(&bounce_lock);
 656
 657         return (0);
 658 }
 659
 660 /*
 661  * Add a single contiguous physical range to the segment list.
 662  */
 663 static bus_size_t
 664 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 665     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 666 {
 667         bus_addr_t baddr, bmask;
 668         int seg;
 669
 670         /*
 671          * Make sure we don't cross any boundaries.
 672          */
 673         bmask = ~(dmat->common.boundary - 1);
 674         if (dmat->common.boundary > 0) {
 675                 baddr = (curaddr + dmat->common.boundary) & bmask;
 676                 if (sgsize > (baddr - curaddr))
 677                         sgsize = (baddr - curaddr);
 678         }
 679
 680         /*
 681          * Insert chunk into a segment, coalescing with
 682          * previous segment if possible.
 683          */
 684         seg = *segp;
 685         if (seg == -1) {
 686                 seg = 0;
 687                 segs[seg].ds_addr = curaddr;
 688                 segs[seg].ds_len = sgsize;
 689         } else {
 690                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 691                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 692                     (dmat->common.boundary == 0 ||
 693                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 694                         segs[seg].ds_len += sgsize;
 695                 else {
 696                         if (++seg >= dmat->common.nsegments)
 697                                 return (0);
 698                         segs[seg].ds_addr = curaddr;
 699                         segs[seg].ds_len = sgsize;
 700                 }
 701         }
 702         *segp = seg;
 703         return (sgsize);
 704 }
 705
 706 /*
 707  * Utility function to load a physical buffer.  segp contains
 708  * the starting segment on entrace, and the ending segment on exit.
 709  */
 710 static int
 711 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 712     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 713     int *segp)
 714 {
 715         struct sync_list *sl;
 716         bus_size_t sgsize;
 717         bus_addr_t curaddr, sl_end;
 718         int error;
 719
 720         if (segs == NULL)
 721                 segs = dmat->segments;
 722
 723         if ((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) {
 724                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 725                 if (map->pagesneeded != 0) {
 726                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 727                         if (error)
 728                                 return (error);
 729                 }
 730         }
 731
 732         sl = map->slist + map->sync_count - 1;
 733         sl_end = 0;
 734
 735         while (buflen > 0) {
 736                 curaddr = buf;
 737                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 738                 if (((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) &&
 739                     map->pagesneeded != 0 &&
 740                     bus_dma_run_filter(&dmat->common, curaddr)) {
 741                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 742                         curaddr = add_bounce_page(dmat, map, 0, curaddr,
 743                             sgsize);
 744                 } else if ((dmat->bounce_flags & BF_COHERENT) == 0) {
 745                         if (map->sync_count > 0)
 746                                 sl_end = sl->paddr + sl->datacount;
 747
 748                         if (map->sync_count == 0 || curaddr != sl_end) {
 749                                 if (++map->sync_count > dmat->common.nsegments)
 750                                         break;
 751                                 sl++;
 752                                 sl->vaddr = 0;
 753                                 sl->paddr = curaddr;
 754                                 sl->datacount = sgsize;
 755                                 sl->pages = PHYS_TO_VM_PAGE(curaddr);
 756                                 KASSERT(sl->pages != NULL,
 757                                     ("%s: page at PA:0x%08lx is not in "
 758                                     "vm_page_array", __func__, curaddr));
 759                         } else
 760                                 sl->datacount += sgsize;
 761                 }
 762                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 763                     segp);
 764                 if (sgsize == 0)
 765                         break;
 766                 buf += sgsize;
 767                 buflen -= sgsize;
 768         }
 769
 770         /*
 771          * Did we fit?
 772          */
 773         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 774 }
 775
 776 /*
 777  * Utility function to load a linear buffer.  segp contains
 778  * the starting segment on entrace, and the ending segment on exit.
 779  */
 780 static int
 781 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 782     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 783     int *segp)
 784 {
 785         struct sync_list *sl;
 786         bus_size_t sgsize, max_sgsize;
 787         bus_addr_t curaddr, sl_pend;
 788         vm_offset_t kvaddr, vaddr, sl_vend;
 789         int error;
 790
 791         if (segs == NULL)
 792                 segs = dmat->segments;
 793
 794         if ((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) {
 795                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 796                 if (map->pagesneeded != 0) {
 797                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 798                         if (error)
 799                                 return (error);
 800                 }
 801         }
 802
 803         sl = map->slist + map->sync_count - 1;
 804         vaddr = (vm_offset_t)buf;
 805         sl_pend = 0;
 806         sl_vend = 0;
 807
 808         while (buflen > 0) {
 809                 /*
 810                  * Get the physical address for this segment.
 811                  */
 812                 if (pmap == kernel_pmap) {
 813                         curaddr = pmap_kextract(vaddr);
 814                         kvaddr = vaddr;
 815                 } else {
 816                         curaddr = pmap_extract(pmap, vaddr);
 817                         kvaddr = 0;
 818                 }
 819
 820                 /*
 821                  * Compute the segment size, and adjust counts.
 822                  */
 823                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 824                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 825                 if (((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) &&
 826                     map->pagesneeded != 0 &&
 827                     bus_dma_run_filter(&dmat->common, curaddr)) {
 828                         sgsize = roundup2(sgsize, dmat->common.alignment);
 829                         sgsize = MIN(sgsize, max_sgsize);
 830                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr,
 831                             sgsize);
 832                 } else if ((dmat->bounce_flags & BF_COHERENT) == 0) {
 833                         sgsize = MIN(sgsize, max_sgsize);
 834                         if (map->sync_count > 0) {
 835                                 sl_pend = sl->paddr + sl->datacount;
 836                                 sl_vend = sl->vaddr + sl->datacount;
 837                         }
 838
 839                         if (map->sync_count == 0 ||
 840                             (kvaddr != 0 && kvaddr != sl_vend) ||
 841                             (curaddr != sl_pend)) {
 842                                 if (++map->sync_count > dmat->common.nsegments)
 843                                         goto cleanup;
 844                                 sl++;
 845                                 sl->vaddr = kvaddr;
 846                                 sl->paddr = curaddr;
 847                                 if (kvaddr != 0) {
 848                                         sl->pages = NULL;
 849                                 } else {
 850                                         sl->pages = PHYS_TO_VM_PAGE(curaddr);
 851                                         KASSERT(sl->pages != NULL,
 852                                             ("%s: page at PA:0x%08lx is not "
 853                                             "in vm_page_array", __func__,
 854                                             curaddr));
 855                                 }
 856                                 sl->datacount = sgsize;
 857                         } else
 858                                 sl->datacount += sgsize;
 859                 } else {
 860                         sgsize = MIN(sgsize, max_sgsize);
 861                 }
 862                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 863                     segp);
 864                 if (sgsize == 0)
 865                         break;
 866                 vaddr += sgsize;
 867                 buflen -= sgsize;
 868         }
 869
 870 cleanup:
 871         /*
 872          * Did we fit?
 873          */
 874         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 875 }
 876
 877 static void
 878 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 879     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 880 {
 881
 882         if ((map->flags & DMAMAP_COULD_BOUNCE) == 0)
 883                 return;
 884         map->mem = *mem;
 885         map->dmat = dmat;
 886         map->callback = callback;
 887         map->callback_arg = callback_arg;
 888 }
 889
 890 static bus_dma_segment_t *
 891 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 892     bus_dma_segment_t *segs, int nsegs, int error)
 893 {
 894
 895         if (segs == NULL)
 896                 segs = dmat->segments;
 897         return (segs);
 898 }
 899
 900 /*
 901  * Release the mapping held by map.
 902  */
 903 static void
 904 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 905 {
 906         struct bounce_page *bpage;
 907
 908         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 909                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 910                 free_bounce_page(dmat, bpage);
 911         }
 912
 913         map->sync_count = 0;
 914 }
 915
 916 static void
 917 dma_preread_safe(vm_offset_t va, vm_size_t size)
 918 {
 919         /*
 920          * Write back any partial cachelines immediately before and
 921          * after the DMA region.
 922          */
 923         if (va & (dcache_line_size - 1))
 924                 cpu_dcache_wb_range(va, 1);
 925         if ((va + size) & (dcache_line_size - 1))
 926                 cpu_dcache_wb_range(va + size, 1);
 927
 928         cpu_dcache_inv_range(va, size);
 929 }
 930
 931 static void
 932 dma_dcache_sync(struct sync_list *sl, bus_dmasync_op_t op)
 933 {
 934         uint32_t len, offset;
 935         vm_page_t m;
 936         vm_paddr_t pa;
 937         vm_offset_t va, tempva;
 938         bus_size_t size;
 939
 940         offset = sl->paddr & PAGE_MASK;
 941         m = sl->pages;
 942         size = sl->datacount;
 943         pa = sl->paddr;
 944
 945         for ( ; size != 0; size -= len, pa += len, offset = 0, ++m) {
 946                 tempva = 0;
 947                 if (sl->vaddr == 0) {
 948                         len = min(PAGE_SIZE - offset, size);
 949                         tempva = pmap_quick_enter_page(m);
 950                         va = tempva | offset;
 951                         KASSERT(pa == (VM_PAGE_TO_PHYS(m) | offset),
 952                             ("unexpected vm_page_t phys: 0x%16lx != 0x%16lx",
 953                             VM_PAGE_TO_PHYS(m) | offset, pa));
 954                 } else {
 955                         len = sl->datacount;
 956                         va = sl->vaddr;
 957                 }
 958
 959                 switch (op) {
 960                 case BUS_DMASYNC_PREWRITE:
 961                 case BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD:
 962                         cpu_dcache_wb_range(va, len);
 963                         break;
 964                 case BUS_DMASYNC_PREREAD:
 965                         /*
 966                          * An mbuf may start in the middle of a cacheline. There
 967                          * will be no cpu writes to the beginning of that line
 968                          * (which contains the mbuf header) while dma is in
 969                          * progress.  Handle that case by doing a writeback of
 970                          * just the first cacheline before invalidating the
 971                          * overall buffer.  Any mbuf in a chain may have this
 972                          * misalignment.  Buffers which are not mbufs bounce if
 973                          * they are not aligned to a cacheline.
 974                          */
 975                         dma_preread_safe(va, len);
 976                         break;
 977                 case BUS_DMASYNC_POSTREAD:
 978                 case BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE:
 979                         cpu_dcache_inv_range(va, len);
 980                         break;
 981                 default:
 982                         panic("unsupported combination of sync operations: "
 983                               "0x%08x\n", op);
 984                 }
 985
 986                 if (tempva != 0)
 987                         pmap_quick_remove_page(tempva);
 988         }
 989 }
 990
 991 static void
 992 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 993     bus_dmasync_op_t op)
 994 {
 995         struct bounce_page *bpage;
 996         struct sync_list *sl, *end;
 997         vm_offset_t datavaddr, tempvaddr;
 998
 999         if (op == BUS_DMASYNC_POSTWRITE)
1000                 return;
1001
1002         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1003                 /*
1004                  * Wait for any DMA operations to complete before the bcopy.
1005                  */
1006                 dsb(sy);
1007         }
1008
1009         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1010                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
1011                     "performing bounce", __func__, dmat, dmat->common.flags,
1012                     op);
1013
1014                 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
1015                         while (bpage != NULL) {
1016                                 tempvaddr = 0;
1017                                 datavaddr = bpage->datavaddr;
1018                                 if (datavaddr == 0) {
1019                                         tempvaddr = pmap_quick_enter_page(
1020                                             bpage->datapage);
1021                                         datavaddr = tempvaddr | bpage->dataoffs;
1022                                 }
1023
1024                                 bcopy((void *)datavaddr,
1025                                     (void *)bpage->vaddr, bpage->datacount);
1026                                 if (tempvaddr != 0)
1027                                         pmap_quick_remove_page(tempvaddr);
1028                                 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1029                                         cpu_dcache_wb_range(bpage->vaddr,
1030                                             bpage->datacount);
1031                                 bpage = STAILQ_NEXT(bpage, links);
1032                         }
1033                         dmat->bounce_zone->total_bounced++;
1034                 } else if ((op & BUS_DMASYNC_PREREAD) != 0) {
1035                         while (bpage != NULL) {
1036                                 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1037                                         cpu_dcache_wbinv_range(bpage->vaddr,
1038                                             bpage->datacount);
1039                                 bpage = STAILQ_NEXT(bpage, links);
1040                         }
1041                 }
1042
1043                 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1044                         while (bpage != NULL) {
1045                                 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1046                                         cpu_dcache_inv_range(bpage->vaddr,
1047                                             bpage->datacount);
1048                                 tempvaddr = 0;
1049                                 datavaddr = bpage->datavaddr;
1050                                 if (datavaddr == 0) {
1051                                         tempvaddr = pmap_quick_enter_page(
1052                                             bpage->datapage);
1053                                         datavaddr = tempvaddr | bpage->dataoffs;
1054                                 }
1055
1056                                 bcopy((void *)bpage->vaddr,
1057                                     (void *)datavaddr, bpage->datacount);
1058
1059                                 if (tempvaddr != 0)
1060                                         pmap_quick_remove_page(tempvaddr);
1061                                 bpage = STAILQ_NEXT(bpage, links);
1062                         }
1063                         dmat->bounce_zone->total_bounced++;
1064                 }
1065         }
1066
1067         /*
1068          * Cache maintenance for normal (non-COHERENT non-bounce) buffers.
1069          */
1070         if (map->sync_count != 0) {
1071                 sl = &map->slist[0];
1072                 end = &map->slist[map->sync_count];
1073                 CTR3(KTR_BUSDMA, "%s: tag %p op 0x%x "
1074                     "performing sync", __func__, dmat, op);
1075
1076                 for ( ; sl != end; ++sl)
1077                         dma_dcache_sync(sl, op);
1078         }
1079
1080         if ((op & (BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE)) != 0) {
1081                 /*
1082                  * Wait for the bcopy to complete before any DMA operations.
1083                  */
1084                 dsb(sy);
1085         }
1086 }
1087
1088 static void
1089 init_bounce_pages(void *dummy __unused)
1090 {
1091
1092         total_bpages = 0;
1093         STAILQ_INIT(&bounce_zone_list);
1094         STAILQ_INIT(&bounce_map_waitinglist);
1095         STAILQ_INIT(&bounce_map_callbacklist);
1096         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1097 }
1098 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1099
1100 static struct sysctl_ctx_list *
1101 busdma_sysctl_tree(struct bounce_zone *bz)
1102 {
1103
1104         return (&bz->sysctl_tree);
1105 }
1106
1107 static struct sysctl_oid *
1108 busdma_sysctl_tree_top(struct bounce_zone *bz)
1109 {
1110
1111         return (bz->sysctl_tree_top);
1112 }
1113
1114 static int
1115 alloc_bounce_zone(bus_dma_tag_t dmat)
1116 {
1117         struct bounce_zone *bz;
1118
1119         /* Check to see if we already have a suitable zone */
1120         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1121                 if ((dmat->common.alignment <= bz->alignment) &&
1122                     (dmat->common.lowaddr >= bz->lowaddr)) {
1123                         dmat->bounce_zone = bz;
1124                         return (0);
1125                 }
1126         }
1127
1128         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1129             M_NOWAIT | M_ZERO)) == NULL)
1130                 return (ENOMEM);
1131
1132         STAILQ_INIT(&bz->bounce_page_list);
1133         bz->free_bpages = 0;
1134         bz->reserved_bpages = 0;
1135         bz->active_bpages = 0;
1136         bz->lowaddr = dmat->common.lowaddr;
1137         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1138         bz->map_count = 0;
1139         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1140         busdma_zonecount++;
1141         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1142         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1143         dmat->bounce_zone = bz;
1144
1145         sysctl_ctx_init(&bz->sysctl_tree);
1146         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1147             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1148             CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
1149         if (bz->sysctl_tree_top == NULL) {
1150                 sysctl_ctx_free(&bz->sysctl_tree);
1151                 return (0);     /* XXX error code? */
1152         }
1153
1154         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1155             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1156             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1157             "Total bounce pages");
1158         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1159             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1160             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1161             "Free bounce pages");
1162         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1163             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1164             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1165             "Reserved bounce pages");
1166         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1167             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1168             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1169             "Active bounce pages");
1170         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1171             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1172             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1173             "Total bounce requests");
1174         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1175             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1176             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1177             "Total bounce requests that were deferred");
1178         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1179             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1180             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1181         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1182             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1183             "alignment", CTLFLAG_RD, &bz->alignment, "");
1184
1185         return (0);
1186 }
1187
1188 static int
1189 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1190 {
1191         struct bounce_zone *bz;
1192         int count;
1193
1194         bz = dmat->bounce_zone;
1195         count = 0;
1196         while (numpages > 0) {
1197                 struct bounce_page *bpage;
1198
1199                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1200                                                      M_NOWAIT | M_ZERO);
1201
1202                 if (bpage == NULL)
1203                         break;
1204                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1205                     M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
1206                 if (bpage->vaddr == 0) {
1207                         free(bpage, M_DEVBUF);
1208                         break;
1209                 }
1210                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1211                 mtx_lock(&bounce_lock);
1212                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1213                 total_bpages++;
1214                 bz->total_bpages++;
1215                 bz->free_bpages++;
1216                 mtx_unlock(&bounce_lock);
1217                 count++;
1218                 numpages--;
1219         }
1220         return (count);
1221 }
1222
1223 static int
1224 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1225 {
1226         struct bounce_zone *bz;
1227         int pages;
1228
1229         mtx_assert(&bounce_lock, MA_OWNED);
1230         bz = dmat->bounce_zone;
1231         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1232         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1233                 return (map->pagesneeded - (map->pagesreserved + pages));
1234         bz->free_bpages -= pages;
1235         bz->reserved_bpages += pages;
1236         map->pagesreserved += pages;
1237         pages = map->pagesneeded - map->pagesreserved;
1238
1239         return (pages);
1240 }
1241
1242 static bus_addr_t
1243 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1244                 bus_addr_t addr, bus_size_t size)
1245 {
1246         struct bounce_zone *bz;
1247         struct bounce_page *bpage;
1248
1249         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1250         KASSERT((map->flags & DMAMAP_COULD_BOUNCE) != 0,
1251             ("add_bounce_page: bad map %p", map));
1252
1253         bz = dmat->bounce_zone;
1254         if (map->pagesneeded == 0)
1255                 panic("add_bounce_page: map doesn't need any pages");
1256         map->pagesneeded--;
1257
1258         if (map->pagesreserved == 0)
1259                 panic("add_bounce_page: map doesn't need any pages");
1260         map->pagesreserved--;
1261
1262         mtx_lock(&bounce_lock);
1263         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1264         if (bpage == NULL)
1265                 panic("add_bounce_page: free page list is empty");
1266
1267         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1268         bz->reserved_bpages--;
1269         bz->active_bpages++;
1270         mtx_unlock(&bounce_lock);
1271
1272         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1273                 /* Page offset needs to be preserved. */
1274                 bpage->vaddr |= addr & PAGE_MASK;
1275                 bpage->busaddr |= addr & PAGE_MASK;
1276         }
1277         bpage->datavaddr = vaddr;
1278         bpage->datapage = PHYS_TO_VM_PAGE(addr);
1279         bpage->dataoffs = addr & PAGE_MASK;
1280         bpage->datacount = size;
1281         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1282         return (bpage->busaddr);
1283 }
1284
1285 static void
1286 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1287 {
1288         struct bus_dmamap *map;
1289         struct bounce_zone *bz;
1290
1291         bz = dmat->bounce_zone;
1292         bpage->datavaddr = 0;
1293         bpage->datacount = 0;
1294         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1295                 /*
1296                  * Reset the bounce page to start at offset 0.  Other uses
1297                  * of this bounce page may need to store a full page of
1298                  * data and/or assume it starts on a page boundary.
1299                  */
1300                 bpage->vaddr &= ~PAGE_MASK;
1301                 bpage->busaddr &= ~PAGE_MASK;
1302         }
1303
1304         mtx_lock(&bounce_lock);
1305         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1306         bz->free_bpages++;
1307         bz->active_bpages--;
1308         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1309                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1310                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1311                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1312                             map, links);
1313                         busdma_swi_pending = 1;
1314                         bz->total_deferred++;
1315                         swi_sched(vm_ih, 0);
1316                 }
1317         }
1318         mtx_unlock(&bounce_lock);
1319 }
1320
1321 void
1322 busdma_swi(void)
1323 {
1324         bus_dma_tag_t dmat;
1325         struct bus_dmamap *map;
1326
1327         mtx_lock(&bounce_lock);
1328         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1329                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1330                 mtx_unlock(&bounce_lock);
1331                 dmat = map->dmat;
1332                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1333                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1334                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1335                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1336                     BUS_DMA_UNLOCK);
1337                 mtx_lock(&bounce_lock);
1338         }
1339         mtx_unlock(&bounce_lock);
1340 }
1341
1342 struct bus_dma_impl bus_dma_bounce_impl = {
1343         .tag_create = bounce_bus_dma_tag_create,
1344         .tag_destroy = bounce_bus_dma_tag_destroy,
1345         .id_mapped = bounce_bus_dma_id_mapped,
1346         .map_create = bounce_bus_dmamap_create,
1347         .map_destroy = bounce_bus_dmamap_destroy,
1348         .mem_alloc = bounce_bus_dmamem_alloc,
1349         .mem_free = bounce_bus_dmamem_free,
1350         .load_phys = bounce_bus_dmamap_load_phys,
1351         .load_buffer = bounce_bus_dmamap_load_buffer,
1352         .load_ma = bus_dmamap_load_ma_triv,
1353         .map_waitok = bounce_bus_dmamap_waitok,
1354         .map_complete = bounce_bus_dmamap_complete,
1355         .map_unload = bounce_bus_dmamap_unload,
1356         .map_sync = bounce_bus_dmamap_sync
1357 };