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 /*
 416  * Allocate a piece of memory that can be efficiently mapped into
 417  * bus device space based on the constraints lited in the dma tag.
 418  * A dmamap to for use with dmamap_load is also allocated.
 419  */
 420 static int
 421 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 422     bus_dmamap_t *mapp)
 423 {
 424         /*
 425          * XXX ARM64TODO:
 426          * This bus_dma implementation requires IO-Coherent architecutre.
 427          * If IO-Coherency is not guaranteed, the BUS_DMA_COHERENT flag has
 428          * to be implented using non-cacheable memory.
 429          */
 430
 431         vm_memattr_t attr;
 432         int mflags;
 433
 434         if (flags & BUS_DMA_NOWAIT)
 435                 mflags = M_NOWAIT;
 436         else
 437                 mflags = M_WAITOK;
 438
 439         if (dmat->segments == NULL) {
 440                 dmat->segments = (bus_dma_segment_t *)malloc(
 441                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 442                     M_DEVBUF, mflags);
 443                 if (dmat->segments == NULL) {
 444                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 445                             __func__, dmat, dmat->common.flags, ENOMEM);
 446                         return (ENOMEM);
 447                 }
 448         }
 449         if (flags & BUS_DMA_ZERO)
 450                 mflags |= M_ZERO;
 451         if (flags & BUS_DMA_NOCACHE)
 452                 attr = VM_MEMATTR_UNCACHEABLE;
 453         else if ((flags & BUS_DMA_COHERENT) != 0 &&
 454             (dmat->bounce_flags & BF_COHERENT) == 0)
 455                 /*
 456                  * If we have a non-coherent tag, and are trying to allocate
 457                  * a coherent block of memory it needs to be uncached.
 458                  */
 459                 attr = VM_MEMATTR_UNCACHEABLE;
 460         else
 461                 attr = VM_MEMATTR_DEFAULT;
 462
 463         /*
 464          * Create the map, but don't set the could bounce flag as
 465          * this allocation should never bounce;
 466          */
 467         *mapp = alloc_dmamap(dmat, mflags);
 468         if (*mapp == NULL) {
 469                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 470                     __func__, dmat, dmat->common.flags, ENOMEM);
 471                 return (ENOMEM);
 472         }
 473         (*mapp)->flags = DMAMAP_FROM_DMAMEM;
 474
 475         /*
 476          * Allocate the buffer from the malloc(9) allocator if...
 477          *  - It's small enough to fit into a single power of two sized bucket.
 478          *  - The alignment is less than or equal to the maximum size
 479          *  - The low address requirement is fulfilled.
 480          * else allocate non-contiguous pages if...
 481          *  - The page count that could get allocated doesn't exceed
 482          *    nsegments also when the maximum segment size is less
 483          *    than PAGE_SIZE.
 484          *  - The alignment constraint isn't larger than a page boundary.
 485          *  - There are no boundary-crossing constraints.
 486          * else allocate a block of contiguous pages because one or more of the
 487          * constraints is something that only the contig allocator can fulfill.
 488          *
 489          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 490          * below is just a quick hack. The exact alignment guarantees
 491          * of malloc(9) need to be nailed down, and the code below
 492          * should be rewritten to take that into account.
 493          *
 494          * In the meantime warn the user if malloc gets it wrong.
 495          */
 496         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 497            (dmat->common.alignment <= dmat->common.maxsize) &&
 498             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 499             attr == VM_MEMATTR_DEFAULT) {
 500                 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
 501         } else if (dmat->common.nsegments >=
 502             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
 503             dmat->common.alignment <= PAGE_SIZE &&
 504             (dmat->common.boundary % PAGE_SIZE) == 0) {
 505                 /* Page-based multi-segment allocations allowed */
 506                 *vaddr = (void *)kmem_alloc_attr(dmat->common.maxsize, mflags,
 507                     0ul, dmat->common.lowaddr, attr);
 508                 dmat->bounce_flags |= BF_KMEM_ALLOC;
 509         } else {
 510                 *vaddr = (void *)kmem_alloc_contig(dmat->common.maxsize, mflags,
 511                     0ul, dmat->common.lowaddr, dmat->common.alignment != 0 ?
 512                     dmat->common.alignment : 1ul, dmat->common.boundary, attr);
 513                 dmat->bounce_flags |= BF_KMEM_ALLOC;
 514         }
 515         if (*vaddr == NULL) {
 516                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 517                     __func__, dmat, dmat->common.flags, ENOMEM);
 518                 free(*mapp, M_DEVBUF);
 519                 return (ENOMEM);
 520         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 521                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 522         }
 523         dmat->map_count++;
 524         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 525             __func__, dmat, dmat->common.flags, 0);
 526         return (0);
 527 }
 528
 529 /*
 530  * Free a piece of memory and it's allociated dmamap, that was allocated
 531  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 532  */
 533 static void
 534 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 535 {
 536
 537         /*
 538          * Check the map came from bounce_bus_dmamem_alloc, so the map
 539          * should be NULL and the BF_KMEM_ALLOC flag cleared if malloc()
 540          * was used and set if kmem_alloc_contig() was used.
 541          */
 542         if ((map->flags & DMAMAP_FROM_DMAMEM) == 0)
 543                 panic("bus_dmamem_free: Invalid map freed\n");
 544         if ((dmat->bounce_flags & BF_KMEM_ALLOC) == 0)
 545                 free(vaddr, M_DEVBUF);
 546         else
 547                 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 548         free(map, M_DEVBUF);
 549         dmat->map_count--;
 550         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 551             dmat->bounce_flags);
 552 }
 553
 554 static bool
 555 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
 556     int *pagesneeded)
 557 {
 558         bus_addr_t curaddr;
 559         bus_size_t sgsize;
 560         int count;
 561
 562         /*
 563          * Count the number of bounce pages needed in order to
 564          * complete this transfer
 565          */
 566         count = 0;
 567         curaddr = buf;
 568         while (buflen != 0) {
 569                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 570                 if (bus_dma_run_filter(&dmat->common, curaddr)) {
 571                         sgsize = MIN(sgsize,
 572                             PAGE_SIZE - (curaddr & PAGE_MASK));
 573                         if (pagesneeded == NULL)
 574                                 return (true);
 575                         count++;
 576                 }
 577                 curaddr += sgsize;
 578                 buflen -= sgsize;
 579         }
 580
 581         if (pagesneeded != NULL)
 582                 *pagesneeded = count;
 583         return (count != 0);
 584 }
 585
 586 static void
 587 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 588     bus_size_t buflen, int flags)
 589 {
 590
 591         if ((map->flags & DMAMAP_COULD_BOUNCE) != 0 && map->pagesneeded == 0) {
 592                 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
 593                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 594         }
 595 }
 596
 597 static void
 598 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 599     void *buf, bus_size_t buflen, int flags)
 600 {
 601         vm_offset_t vaddr;
 602         vm_offset_t vendaddr;
 603         bus_addr_t paddr;
 604         bus_size_t sg_len;
 605
 606         if ((map->flags & DMAMAP_COULD_BOUNCE) != 0 && map->pagesneeded == 0) {
 607                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 608                     "alignment= %d", dmat->common.lowaddr,
 609                     ptoa((vm_paddr_t)Maxmem),
 610                     dmat->common.boundary, dmat->common.alignment);
 611                 CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d", map,
 612                     map->pagesneeded);
 613                 /*
 614                  * Count the number of bounce pages
 615                  * needed in order to complete this transfer
 616                  */
 617                 vaddr = (vm_offset_t)buf;
 618                 vendaddr = (vm_offset_t)buf + buflen;
 619
 620                 while (vaddr < vendaddr) {
 621                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 622                         if (pmap == kernel_pmap)
 623                                 paddr = pmap_kextract(vaddr);
 624                         else
 625                                 paddr = pmap_extract(pmap, vaddr);
 626                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 627                                 sg_len = roundup2(sg_len,
 628                                     dmat->common.alignment);
 629                                 map->pagesneeded++;
 630                         }
 631                         vaddr += sg_len;
 632                 }
 633                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 634         }
 635 }
 636
 637 static int
 638 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 639 {
 640
 641         /* Reserve Necessary Bounce Pages */
 642         mtx_lock(&bounce_lock);
 643         if (flags & BUS_DMA_NOWAIT) {
 644                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 645                         mtx_unlock(&bounce_lock);
 646                         return (ENOMEM);
 647                 }
 648         } else {
 649                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 650                         /* Queue us for resources */
 651                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 652                         mtx_unlock(&bounce_lock);
 653                         return (EINPROGRESS);
 654                 }
 655         }
 656         mtx_unlock(&bounce_lock);
 657
 658         return (0);
 659 }
 660
 661 /*
 662  * Add a single contiguous physical range to the segment list.
 663  */
 664 static bus_size_t
 665 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 666     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 667 {
 668         bus_addr_t baddr, bmask;
 669         int seg;
 670
 671         /*
 672          * Make sure we don't cross any boundaries.
 673          */
 674         bmask = ~(dmat->common.boundary - 1);
 675         if (dmat->common.boundary > 0) {
 676                 baddr = (curaddr + dmat->common.boundary) & bmask;
 677                 if (sgsize > (baddr - curaddr))
 678                         sgsize = (baddr - curaddr);
 679         }
 680
 681         /*
 682          * Insert chunk into a segment, coalescing with
 683          * previous segment if possible.
 684          */
 685         seg = *segp;
 686         if (seg == -1) {
 687                 seg = 0;
 688                 segs[seg].ds_addr = curaddr;
 689                 segs[seg].ds_len = sgsize;
 690         } else {
 691                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 692                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 693                     (dmat->common.boundary == 0 ||
 694                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 695                         segs[seg].ds_len += sgsize;
 696                 else {
 697                         if (++seg >= dmat->common.nsegments)
 698                                 return (0);
 699                         segs[seg].ds_addr = curaddr;
 700                         segs[seg].ds_len = sgsize;
 701                 }
 702         }
 703         *segp = seg;
 704         return (sgsize);
 705 }
 706
 707 /*
 708  * Utility function to load a physical buffer.  segp contains
 709  * the starting segment on entrace, and the ending segment on exit.
 710  */
 711 static int
 712 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 713     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 714     int *segp)
 715 {
 716         struct sync_list *sl;
 717         bus_size_t sgsize;
 718         bus_addr_t curaddr, sl_end;
 719         int error;
 720
 721         if (segs == NULL)
 722                 segs = dmat->segments;
 723
 724         if ((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) {
 725                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 726                 if (map->pagesneeded != 0) {
 727                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 728                         if (error)
 729                                 return (error);
 730                 }
 731         }
 732
 733         sl = map->slist + map->sync_count - 1;
 734         sl_end = 0;
 735
 736         while (buflen > 0) {
 737                 curaddr = buf;
 738                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 739                 if (((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) &&
 740                     map->pagesneeded != 0 &&
 741                     bus_dma_run_filter(&dmat->common, curaddr)) {
 742                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 743                         curaddr = add_bounce_page(dmat, map, 0, curaddr,
 744                             sgsize);
 745                 } else if ((dmat->bounce_flags & BF_COHERENT) == 0) {
 746                         if (map->sync_count > 0)
 747                                 sl_end = sl->paddr + sl->datacount;
 748
 749                         if (map->sync_count == 0 || curaddr != sl_end) {
 750                                 if (++map->sync_count > dmat->common.nsegments)
 751                                         break;
 752                                 sl++;
 753                                 sl->vaddr = 0;
 754                                 sl->paddr = curaddr;
 755                                 sl->datacount = sgsize;
 756                                 sl->pages = PHYS_TO_VM_PAGE(curaddr);
 757                                 KASSERT(sl->pages != NULL,
 758                                     ("%s: page at PA:0x%08lx is not in "
 759                                     "vm_page_array", __func__, curaddr));
 760                         } else
 761                                 sl->datacount += sgsize;
 762                 }
 763                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 764                     segp);
 765                 if (sgsize == 0)
 766                         break;
 767                 buf += sgsize;
 768                 buflen -= sgsize;
 769         }
 770
 771         /*
 772          * Did we fit?
 773          */
 774         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 775 }
 776
 777 /*
 778  * Utility function to load a linear buffer.  segp contains
 779  * the starting segment on entrace, and the ending segment on exit.
 780  */
 781 static int
 782 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 783     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 784     int *segp)
 785 {
 786         struct sync_list *sl;
 787         bus_size_t sgsize, max_sgsize;
 788         bus_addr_t curaddr, sl_pend;
 789         vm_offset_t kvaddr, vaddr, sl_vend;
 790         int error;
 791
 792         if (segs == NULL)
 793                 segs = dmat->segments;
 794
 795         if ((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) {
 796                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 797                 if (map->pagesneeded != 0) {
 798                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 799                         if (error)
 800                                 return (error);
 801                 }
 802         }
 803
 804         sl = map->slist + map->sync_count - 1;
 805         vaddr = (vm_offset_t)buf;
 806         sl_pend = 0;
 807         sl_vend = 0;
 808
 809         while (buflen > 0) {
 810                 /*
 811                  * Get the physical address for this segment.
 812                  */
 813                 if (pmap == kernel_pmap) {
 814                         curaddr = pmap_kextract(vaddr);
 815                         kvaddr = vaddr;
 816                 } else {
 817                         curaddr = pmap_extract(pmap, vaddr);
 818                         kvaddr = 0;
 819                 }
 820
 821                 /*
 822                  * Compute the segment size, and adjust counts.
 823                  */
 824                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 825                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 826                 if (((dmat->bounce_flags & BF_COULD_BOUNCE) != 0) &&
 827                     map->pagesneeded != 0 &&
 828                     bus_dma_run_filter(&dmat->common, curaddr)) {
 829                         sgsize = roundup2(sgsize, dmat->common.alignment);
 830                         sgsize = MIN(sgsize, max_sgsize);
 831                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr,
 832                             sgsize);
 833                 } else if ((dmat->bounce_flags & BF_COHERENT) == 0) {
 834                         sgsize = MIN(sgsize, max_sgsize);
 835                         if (map->sync_count > 0) {
 836                                 sl_pend = sl->paddr + sl->datacount;
 837                                 sl_vend = sl->vaddr + sl->datacount;
 838                         }
 839
 840                         if (map->sync_count == 0 ||
 841                             (kvaddr != 0 && kvaddr != sl_vend) ||
 842                             (curaddr != sl_pend)) {
 843
 844                                 if (++map->sync_count > dmat->common.nsegments)
 845                                         goto cleanup;
 846                                 sl++;
 847                                 sl->vaddr = kvaddr;
 848                                 sl->paddr = curaddr;
 849                                 if (kvaddr != 0) {
 850                                         sl->pages = NULL;
 851                                 } else {
 852                                         sl->pages = PHYS_TO_VM_PAGE(curaddr);
 853                                         KASSERT(sl->pages != NULL,
 854                                             ("%s: page at PA:0x%08lx is not "
 855                                             "in vm_page_array", __func__,
 856                                             curaddr));
 857                                 }
 858                                 sl->datacount = sgsize;
 859                         } else
 860                                 sl->datacount += sgsize;
 861                 } else {
 862                         sgsize = MIN(sgsize, max_sgsize);
 863                 }
 864                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 865                     segp);
 866                 if (sgsize == 0)
 867                         break;
 868                 vaddr += sgsize;
 869                 buflen -= sgsize;
 870         }
 871
 872 cleanup:
 873         /*
 874          * Did we fit?
 875          */
 876         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 877 }
 878
 879 static void
 880 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 881     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 882 {
 883
 884         if ((map->flags & DMAMAP_COULD_BOUNCE) == 0)
 885                 return;
 886         map->mem = *mem;
 887         map->dmat = dmat;
 888         map->callback = callback;
 889         map->callback_arg = callback_arg;
 890 }
 891
 892 static bus_dma_segment_t *
 893 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 894     bus_dma_segment_t *segs, int nsegs, int error)
 895 {
 896
 897         if (segs == NULL)
 898                 segs = dmat->segments;
 899         return (segs);
 900 }
 901
 902 /*
 903  * Release the mapping held by map.
 904  */
 905 static void
 906 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 907 {
 908         struct bounce_page *bpage;
 909
 910         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 911                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 912                 free_bounce_page(dmat, bpage);
 913         }
 914
 915         map->sync_count = 0;
 916 }
 917
 918 static void
 919 dma_preread_safe(vm_offset_t va, vm_size_t size)
 920 {
 921         /*
 922          * Write back any partial cachelines immediately before and
 923          * after the DMA region.
 924          */
 925         if (va & (dcache_line_size - 1))
 926                 cpu_dcache_wb_range(va, 1);
 927         if ((va + size) & (dcache_line_size - 1))
 928                 cpu_dcache_wb_range(va + size, 1);
 929
 930         cpu_dcache_inv_range(va, size);
 931 }
 932
 933 static void
 934 dma_dcache_sync(struct sync_list *sl, bus_dmasync_op_t op)
 935 {
 936         uint32_t len, offset;
 937         vm_page_t m;
 938         vm_paddr_t pa;
 939         vm_offset_t va, tempva;
 940         bus_size_t size;
 941
 942         offset = sl->paddr & PAGE_MASK;
 943         m = sl->pages;
 944         size = sl->datacount;
 945         pa = sl->paddr;
 946
 947         for ( ; size != 0; size -= len, pa += len, offset = 0, ++m) {
 948                 tempva = 0;
 949                 if (sl->vaddr == 0) {
 950                         len = min(PAGE_SIZE - offset, size);
 951                         tempva = pmap_quick_enter_page(m);
 952                         va = tempva | offset;
 953                         KASSERT(pa == (VM_PAGE_TO_PHYS(m) | offset),
 954                             ("unexpected vm_page_t phys: 0x%16lx != 0x%16lx",
 955                             VM_PAGE_TO_PHYS(m) | offset, pa));
 956                 } else {
 957                         len = sl->datacount;
 958                         va = sl->vaddr;
 959                 }
 960
 961                 switch (op) {
 962                 case BUS_DMASYNC_PREWRITE:
 963                 case BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD:
 964                         cpu_dcache_wb_range(va, len);
 965                         break;
 966                 case BUS_DMASYNC_PREREAD:
 967                         /*
 968                          * An mbuf may start in the middle of a cacheline. There
 969                          * will be no cpu writes to the beginning of that line
 970                          * (which contains the mbuf header) while dma is in
 971                          * progress.  Handle that case by doing a writeback of
 972                          * just the first cacheline before invalidating the
 973                          * overall buffer.  Any mbuf in a chain may have this
 974                          * misalignment.  Buffers which are not mbufs bounce if
 975                          * they are not aligned to a cacheline.
 976                          */
 977                         dma_preread_safe(va, len);
 978                         break;
 979                 case BUS_DMASYNC_POSTREAD:
 980                 case BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE:
 981                         cpu_dcache_inv_range(va, len);
 982                         break;
 983                 default:
 984                         panic("unsupported combination of sync operations: "
 985                               "0x%08x\n", op);
 986                 }
 987
 988                 if (tempva != 0)
 989                         pmap_quick_remove_page(tempva);
 990         }
 991 }
 992
 993 static void
 994 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 995     bus_dmasync_op_t op)
 996 {
 997         struct bounce_page *bpage;
 998         struct sync_list *sl, *end;
 999         vm_offset_t datavaddr, tempvaddr;
1000
1001         if (op == BUS_DMASYNC_POSTWRITE)
1002                 return;
1003
1004         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1005                 /*
1006                  * Wait for any DMA operations to complete before the bcopy.
1007                  */
1008                 dsb(sy);
1009         }
1010
1011         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1012                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
1013                     "performing bounce", __func__, dmat, dmat->common.flags,
1014                     op);
1015
1016                 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
1017                         while (bpage != NULL) {
1018                                 tempvaddr = 0;
1019                                 datavaddr = bpage->datavaddr;
1020                                 if (datavaddr == 0) {
1021                                         tempvaddr = pmap_quick_enter_page(
1022                                             bpage->datapage);
1023                                         datavaddr = tempvaddr | bpage->dataoffs;
1024                                 }
1025
1026                                 bcopy((void *)datavaddr,
1027                                     (void *)bpage->vaddr, bpage->datacount);
1028                                 if (tempvaddr != 0)
1029                                         pmap_quick_remove_page(tempvaddr);
1030                                 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1031                                         cpu_dcache_wb_range(bpage->vaddr,
1032                                             bpage->datacount);
1033                                 bpage = STAILQ_NEXT(bpage, links);
1034                         }
1035                         dmat->bounce_zone->total_bounced++;
1036                 } else if ((op & BUS_DMASYNC_PREREAD) != 0) {
1037                         while (bpage != NULL) {
1038                                 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1039                                         cpu_dcache_wbinv_range(bpage->vaddr,
1040                                             bpage->datacount);
1041                                 bpage = STAILQ_NEXT(bpage, links);
1042                         }
1043                 }
1044
1045                 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1046                         while (bpage != NULL) {
1047                                 if ((dmat->bounce_flags & BF_COHERENT) == 0)
1048                                         cpu_dcache_inv_range(bpage->vaddr,
1049                                             bpage->datacount);
1050                                 tempvaddr = 0;
1051                                 datavaddr = bpage->datavaddr;
1052                                 if (datavaddr == 0) {
1053                                         tempvaddr = pmap_quick_enter_page(
1054                                             bpage->datapage);
1055                                         datavaddr = tempvaddr | bpage->dataoffs;
1056                                 }
1057
1058                                 bcopy((void *)bpage->vaddr,
1059                                     (void *)datavaddr, bpage->datacount);
1060
1061                                 if (tempvaddr != 0)
1062                                         pmap_quick_remove_page(tempvaddr);
1063                                 bpage = STAILQ_NEXT(bpage, links);
1064                         }
1065                         dmat->bounce_zone->total_bounced++;
1066                 }
1067         }
1068
1069         /*
1070          * Cache maintenance for normal (non-COHERENT non-bounce) buffers.
1071          */
1072         if (map->sync_count != 0) {
1073                 sl = &map->slist[0];
1074                 end = &map->slist[map->sync_count];
1075                 CTR3(KTR_BUSDMA, "%s: tag %p op 0x%x "
1076                     "performing sync", __func__, dmat, op);
1077
1078                 for ( ; sl != end; ++sl)
1079                         dma_dcache_sync(sl, op);
1080         }
1081
1082         if ((op & (BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE)) != 0) {
1083                 /*
1084                  * Wait for the bcopy to complete before any DMA operations.
1085                  */
1086                 dsb(sy);
1087         }
1088 }
1089
1090 static void
1091 init_bounce_pages(void *dummy __unused)
1092 {
1093
1094         total_bpages = 0;
1095         STAILQ_INIT(&bounce_zone_list);
1096         STAILQ_INIT(&bounce_map_waitinglist);
1097         STAILQ_INIT(&bounce_map_callbacklist);
1098         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1099 }
1100 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1101
1102 static struct sysctl_ctx_list *
1103 busdma_sysctl_tree(struct bounce_zone *bz)
1104 {
1105
1106         return (&bz->sysctl_tree);
1107 }
1108
1109 static struct sysctl_oid *
1110 busdma_sysctl_tree_top(struct bounce_zone *bz)
1111 {
1112
1113         return (bz->sysctl_tree_top);
1114 }
1115
1116 static int
1117 alloc_bounce_zone(bus_dma_tag_t dmat)
1118 {
1119         struct bounce_zone *bz;
1120
1121         /* Check to see if we already have a suitable zone */
1122         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1123                 if ((dmat->common.alignment <= bz->alignment) &&
1124                     (dmat->common.lowaddr >= bz->lowaddr)) {
1125                         dmat->bounce_zone = bz;
1126                         return (0);
1127                 }
1128         }
1129
1130         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1131             M_NOWAIT | M_ZERO)) == NULL)
1132                 return (ENOMEM);
1133
1134         STAILQ_INIT(&bz->bounce_page_list);
1135         bz->free_bpages = 0;
1136         bz->reserved_bpages = 0;
1137         bz->active_bpages = 0;
1138         bz->lowaddr = dmat->common.lowaddr;
1139         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1140         bz->map_count = 0;
1141         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1142         busdma_zonecount++;
1143         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1144         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1145         dmat->bounce_zone = bz;
1146
1147         sysctl_ctx_init(&bz->sysctl_tree);
1148         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1149             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1150             CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
1151         if (bz->sysctl_tree_top == NULL) {
1152                 sysctl_ctx_free(&bz->sysctl_tree);
1153                 return (0);     /* XXX error code? */
1154         }
1155
1156         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1157             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1158             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1159             "Total bounce pages");
1160         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1161             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1162             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1163             "Free bounce pages");
1164         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1165             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1166             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1167             "Reserved bounce pages");
1168         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1169             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1170             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1171             "Active bounce pages");
1172         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1173             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1174             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1175             "Total bounce requests");
1176         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1177             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1178             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1179             "Total bounce requests that were deferred");
1180         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1181             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1182             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1183         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1184             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1185             "alignment", CTLFLAG_RD, &bz->alignment, "");
1186
1187         return (0);
1188 }
1189
1190 static int
1191 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1192 {
1193         struct bounce_zone *bz;
1194         int count;
1195
1196         bz = dmat->bounce_zone;
1197         count = 0;
1198         while (numpages > 0) {
1199                 struct bounce_page *bpage;
1200
1201                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1202                                                      M_NOWAIT | M_ZERO);
1203
1204                 if (bpage == NULL)
1205                         break;
1206                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1207                     M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
1208                 if (bpage->vaddr == 0) {
1209                         free(bpage, M_DEVBUF);
1210                         break;
1211                 }
1212                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1213                 mtx_lock(&bounce_lock);
1214                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1215                 total_bpages++;
1216                 bz->total_bpages++;
1217                 bz->free_bpages++;
1218                 mtx_unlock(&bounce_lock);
1219                 count++;
1220                 numpages--;
1221         }
1222         return (count);
1223 }
1224
1225 static int
1226 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1227 {
1228         struct bounce_zone *bz;
1229         int pages;
1230
1231         mtx_assert(&bounce_lock, MA_OWNED);
1232         bz = dmat->bounce_zone;
1233         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1234         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1235                 return (map->pagesneeded - (map->pagesreserved + pages));
1236         bz->free_bpages -= pages;
1237         bz->reserved_bpages += pages;
1238         map->pagesreserved += pages;
1239         pages = map->pagesneeded - map->pagesreserved;
1240
1241         return (pages);
1242 }
1243
1244 static bus_addr_t
1245 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1246                 bus_addr_t addr, bus_size_t size)
1247 {
1248         struct bounce_zone *bz;
1249         struct bounce_page *bpage;
1250
1251         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1252         KASSERT((map->flags & DMAMAP_COULD_BOUNCE) != 0,
1253             ("add_bounce_page: bad map %p", map));
1254
1255         bz = dmat->bounce_zone;
1256         if (map->pagesneeded == 0)
1257                 panic("add_bounce_page: map doesn't need any pages");
1258         map->pagesneeded--;
1259
1260         if (map->pagesreserved == 0)
1261                 panic("add_bounce_page: map doesn't need any pages");
1262         map->pagesreserved--;
1263
1264         mtx_lock(&bounce_lock);
1265         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1266         if (bpage == NULL)
1267                 panic("add_bounce_page: free page list is empty");
1268
1269         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1270         bz->reserved_bpages--;
1271         bz->active_bpages++;
1272         mtx_unlock(&bounce_lock);
1273
1274         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1275                 /* Page offset needs to be preserved. */
1276                 bpage->vaddr |= addr & PAGE_MASK;
1277                 bpage->busaddr |= addr & PAGE_MASK;
1278         }
1279         bpage->datavaddr = vaddr;
1280         bpage->datapage = PHYS_TO_VM_PAGE(addr);
1281         bpage->dataoffs = addr & PAGE_MASK;
1282         bpage->datacount = size;
1283         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1284         return (bpage->busaddr);
1285 }
1286
1287 static void
1288 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1289 {
1290         struct bus_dmamap *map;
1291         struct bounce_zone *bz;
1292
1293         bz = dmat->bounce_zone;
1294         bpage->datavaddr = 0;
1295         bpage->datacount = 0;
1296         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1297                 /*
1298                  * Reset the bounce page to start at offset 0.  Other uses
1299                  * of this bounce page may need to store a full page of
1300                  * data and/or assume it starts on a page boundary.
1301                  */
1302                 bpage->vaddr &= ~PAGE_MASK;
1303                 bpage->busaddr &= ~PAGE_MASK;
1304         }
1305
1306         mtx_lock(&bounce_lock);
1307         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1308         bz->free_bpages++;
1309         bz->active_bpages--;
1310         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1311                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1312                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1313                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1314                             map, links);
1315                         busdma_swi_pending = 1;
1316                         bz->total_deferred++;
1317                         swi_sched(vm_ih, 0);
1318                 }
1319         }
1320         mtx_unlock(&bounce_lock);
1321 }
1322
1323 void
1324 busdma_swi(void)
1325 {
1326         bus_dma_tag_t dmat;
1327         struct bus_dmamap *map;
1328
1329         mtx_lock(&bounce_lock);
1330         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1331                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1332                 mtx_unlock(&bounce_lock);
1333                 dmat = map->dmat;
1334                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1335                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1336                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1337                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1338                     BUS_DMA_UNLOCK);
1339                 mtx_lock(&bounce_lock);
1340         }
1341         mtx_unlock(&bounce_lock);
1342 }
1343
1344 struct bus_dma_impl bus_dma_bounce_impl = {
1345         .tag_create = bounce_bus_dma_tag_create,
1346         .tag_destroy = bounce_bus_dma_tag_destroy,
1347         .id_mapped = bounce_bus_dma_id_mapped,
1348         .map_create = bounce_bus_dmamap_create,
1349         .map_destroy = bounce_bus_dmamap_destroy,
1350         .mem_alloc = bounce_bus_dmamem_alloc,
1351         .mem_free = bounce_bus_dmamem_free,
1352         .load_phys = bounce_bus_dmamap_load_phys,
1353         .load_buffer = bounce_bus_dmamap_load_buffer,
1354         .load_ma = bus_dmamap_load_ma_triv,
1355         .map_waitok = bounce_bus_dmamap_waitok,
1356         .map_complete = bounce_bus_dmamap_complete,
1357         .map_unload = bounce_bus_dmamap_unload,
1358         .map_sync = bounce_bus_dmamap_sync
1359 };