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