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_COHERENT         (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 static bool
 166 might_bounce(bus_dma_tag_t dmat)
 167 {
 168
 169         if ((dmat->bounce_flags & BF_COULD_BOUNCE) != 0)
 170                 return (true);
 171
 172         return (false);
 173 }
 174
 175 static bool
 176 must_bounce(bus_dma_tag_t dmat, bus_addr_t paddr)
 177 {
 178
 179         if ((dmat->bounce_flags & BF_COULD_BOUNCE) != 0 &&
 180             bus_dma_run_filter(&dmat->common, paddr))
 181                 return (true);
 182
 183         return (false);
 184 }
 185
 186 /*
 187  * Allocate a device specific dma_tag.
 188  */
 189 static int
 190 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 191     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 192     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 193     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 194     void *lockfuncarg, bus_dma_tag_t *dmat)
 195 {
 196         bus_dma_tag_t newtag;
 197         int error;
 198
 199         *dmat = NULL;
 200         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 201             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 202             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 203             sizeof (struct bus_dma_tag), (void **)&newtag);
 204         if (error != 0)
 205                 return (error);
 206
 207         newtag->common.impl = &bus_dma_bounce_impl;
 208         newtag->map_count = 0;
 209         newtag->segments = NULL;
 210
 211         if ((flags & BUS_DMA_COHERENT) != 0)
 212                 newtag->bounce_flags |= BF_COHERENT;
 213
 214         if (parent != NULL) {
 215                 if ((newtag->common.filter != NULL ||
 216                     (parent->bounce_flags & BF_COULD_BOUNCE) != 0))
 217                         newtag->bounce_flags |= BF_COULD_BOUNCE;
 218
 219                 /* Copy some flags from the parent */
 220                 newtag->bounce_flags |= parent->bounce_flags & BF_COHERENT;
 221         }
 222
 223         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 224             newtag->common.alignment > 1)
 225                 newtag->bounce_flags |= BF_COULD_BOUNCE;
 226
 227         if (((newtag->bounce_flags & BF_COULD_BOUNCE) != 0) &&
 228             (flags & BUS_DMA_ALLOCNOW) != 0) {
 229                 struct bounce_zone *bz;
 230
 231                 /* Must bounce */
 232                 if ((error = alloc_bounce_zone(newtag)) != 0) {
 233                         free(newtag, M_DEVBUF);
 234                         return (error);
 235                 }
 236                 bz = newtag->bounce_zone;
 237
 238                 if (ptoa(bz->total_bpages) < maxsize) {
 239                         int pages;
 240
 241                         pages = atop(round_page(maxsize)) - bz->total_bpages;
 242
 243                         /* Add pages to our bounce pool */
 244                         if (alloc_bounce_pages(newtag, pages) < pages)
 245                                 error = ENOMEM;
 246                 }
 247                 /* Performed initial allocation */
 248                 newtag->bounce_flags |= BF_MIN_ALLOC_COMP;
 249         } else
 250                 error = 0;
 251
 252         if (error != 0)
 253                 free(newtag, M_DEVBUF);
 254         else
 255                 *dmat = newtag;
 256         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 257             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 258             error);
 259         return (error);
 260 }
 261
 262 static int
 263 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 264 {
 265         bus_dma_tag_t dmat_copy, parent;
 266         int error;
 267
 268         error = 0;
 269         dmat_copy = dmat;
 270
 271         if (dmat != NULL) {
 272                 if (dmat->map_count != 0) {
 273                         error = EBUSY;
 274                         goto out;
 275                 }
 276                 while (dmat != NULL) {
 277                         parent = (bus_dma_tag_t)dmat->common.parent;
 278                         atomic_subtract_int(&dmat->common.ref_count, 1);
 279                         if (dmat->common.ref_count == 0) {
 280                                 if (dmat->segments != NULL)
 281                                         free(dmat->segments, M_DEVBUF);
 282                                 free(dmat, M_DEVBUF);
 283                                 /*
 284                                  * Last reference count, so
 285                                  * release our reference
 286                                  * count on our parent.
 287                                  */
 288                                 dmat = parent;
 289                         } else
 290                                 dmat = NULL;
 291                 }
 292         }
 293 out:
 294         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 295         return (error);
 296 }
 297
 298 static bool
 299 bounce_bus_dma_id_mapped(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen)
 300 {
 301
 302         if (!might_bounce(dmat))
 303                 return (true);
 304         return (!_bus_dmamap_pagesneeded(dmat, buf, buflen, NULL));
 305 }
 306
 307 static bus_dmamap_t
 308 alloc_dmamap(bus_dma_tag_t dmat, int flags)
 309 {
 310         u_long mapsize;
 311         bus_dmamap_t map;
 312
 313         mapsize = sizeof(*map);
 314         mapsize += sizeof(struct sync_list) * dmat->common.nsegments;
 315         map = malloc(mapsize, M_DEVBUF, flags | M_ZERO);
 316         if (map == NULL)
 317                 return (NULL);
 318
 319         /* Initialize the new map */
 320         STAILQ_INIT(&map->bpages);
 321
 322         return (map);
 323 }
 324
 325 /*
 326  * Allocate a handle for mapping from kva/uva/physical
 327  * address space into bus device space.
 328  */
 329 static int
 330 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 331 {
 332         struct bounce_zone *bz;
 333         int error, maxpages, pages;
 334
 335         error = 0;
 336
 337         if (dmat->segments == NULL) {
 338                 dmat->segments = (bus_dma_segment_t *)malloc(
 339                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 340                     M_DEVBUF, M_NOWAIT);
 341                 if (dmat->segments == NULL) {
 342                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 343                             __func__, dmat, ENOMEM);
 344                         return (ENOMEM);
 345                 }
 346         }
 347
 348         *mapp = alloc_dmamap(dmat, M_NOWAIT);
 349         if (*mapp == NULL) {
 350                 CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 351                     __func__, dmat, ENOMEM);
 352                 return (ENOMEM);
 353         }
 354
 355         /*
 356          * Bouncing might be required if the driver asks for an active
 357          * exclusion region, a data alignment that is stricter than 1, and/or
 358          * an active address boundary.
 359          */
 360         if (dmat->bounce_flags & BF_COULD_BOUNCE) {
 361                 /* Must bounce */
 362                 if (dmat->bounce_zone == NULL) {
 363                         if ((error = alloc_bounce_zone(dmat)) != 0) {
 364                                 free(*mapp, M_DEVBUF);
 365                                 return (error);
 366                         }
 367                 }
 368                 bz = dmat->bounce_zone;
 369
 370                 /*
 371                  * Attempt to add pages to our pool on a per-instance
 372                  * basis up to a sane limit.
 373                  */
 374                 if (dmat->common.alignment > 1)
 375                         maxpages = MAX_BPAGES;
 376                 else
 377                         maxpages = MIN(MAX_BPAGES, Maxmem -
 378                             atop(dmat->common.lowaddr));
 379                 if ((dmat->bounce_flags & BF_MIN_ALLOC_COMP) == 0 ||
 380                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 381                         pages = MAX(atop(dmat->common.maxsize), 1);
 382                         pages = MIN(maxpages - bz->total_bpages, pages);
 383                         pages = MAX(pages, 1);
 384                         if (alloc_bounce_pages(dmat, pages) < pages)
 385                                 error = ENOMEM;
 386                         if ((dmat->bounce_flags & BF_MIN_ALLOC_COMP)
 387                             == 0) {
 388                                 if (error == 0) {
 389                                         dmat->bounce_flags |=
 390                                             BF_MIN_ALLOC_COMP;
 391                                 }
 392                         } else
 393                                 error = 0;
 394                 }
 395                 bz->map_count++;
 396         }
 397         if (error == 0) {
 398                 dmat->map_count++;
 399                 if ((dmat->bounce_flags & BF_COHERENT) != 0)
 400                         (*mapp)->flags |= DMAMAP_COHERENT;
 401         } else {
 402                 free(*mapp, M_DEVBUF);
 403         }
 404         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 405             __func__, dmat, dmat->common.flags, error);
 406         return (error);
 407 }
 408
 409 /*
 410  * Destroy a handle for mapping from kva/uva/physical
 411  * address space into bus device space.
 412  */
 413 static int
 414 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 415 {
 416
 417         /* Check we are destroying the correct map type */
 418         if ((map->flags & DMAMAP_FROM_DMAMEM) != 0)
 419                 panic("bounce_bus_dmamap_destroy: Invalid map freed\n");
 420
 421         if (STAILQ_FIRST(&map->bpages) != NULL || map->sync_count != 0) {
 422                 CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, EBUSY);
 423                 return (EBUSY);
 424         }
 425         if (dmat->bounce_zone)
 426                 dmat->bounce_zone->map_count--;
 427         free(map, M_DEVBUF);
 428         dmat->map_count--;
 429         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 430         return (0);
 431 }
 432
 433 /*
 434  * Allocate a piece of memory that can be efficiently mapped into
 435  * bus device space based on the constraints lited in the dma tag.
 436  * A dmamap to for use with dmamap_load is also allocated.
 437  */
 438 static int
 439 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 440     bus_dmamap_t *mapp)
 441 {
 442         /*
 443          * XXX ARM64TODO:
 444          * This bus_dma implementation requires IO-Coherent architecutre.
 445          * If IO-Coherency is not guaranteed, the BUS_DMA_COHERENT flag has
 446          * to be implented using non-cacheable memory.
 447          */
 448
 449         vm_memattr_t attr;
 450         int mflags;
 451
 452         if (flags & BUS_DMA_NOWAIT)
 453                 mflags = M_NOWAIT;
 454         else
 455                 mflags = M_WAITOK;
 456
 457         if (dmat->segments == NULL) {
 458                 dmat->segments = (bus_dma_segment_t *)malloc(
 459                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 460                     M_DEVBUF, mflags);
 461                 if (dmat->segments == NULL) {
 462                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 463                             __func__, dmat, dmat->common.flags, ENOMEM);
 464                         return (ENOMEM);
 465                 }
 466         }
 467         if (flags & BUS_DMA_ZERO)
 468                 mflags |= M_ZERO;
 469         if (flags & BUS_DMA_NOCACHE)
 470                 attr = VM_MEMATTR_UNCACHEABLE;
 471         else if ((flags & BUS_DMA_COHERENT) != 0 &&
 472             (dmat->bounce_flags & BF_COHERENT) == 0)
 473                 /*
 474                  * If we have a non-coherent tag, and are trying to allocate
 475                  * a coherent block of memory it needs to be uncached.
 476                  */
 477                 attr = VM_MEMATTR_UNCACHEABLE;
 478         else
 479                 attr = VM_MEMATTR_DEFAULT;
 480
 481         /*
 482          * Create the map, but don't set the could bounce flag as
 483          * this allocation should never bounce;
 484          */
 485         *mapp = alloc_dmamap(dmat, mflags);
 486         if (*mapp == NULL) {
 487                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 488                     __func__, dmat, dmat->common.flags, ENOMEM);
 489                 return (ENOMEM);
 490         }
 491
 492         /*
 493          * Mark the map as coherent if we used uncacheable memory or the
 494          * tag was already marked as coherent.
 495          */
 496         if (attr == VM_MEMATTR_UNCACHEABLE ||
 497             (dmat->bounce_flags & BF_COHERENT) != 0)
 498                 (*mapp)->flags |= DMAMAP_COHERENT;
 499
 500         (*mapp)->flags |= DMAMAP_FROM_DMAMEM;
 501
 502         /*
 503          * Allocate the buffer from the malloc(9) allocator if...
 504          *  - It's small enough to fit into a single power of two sized bucket.
 505          *  - The alignment is less than or equal to the maximum size
 506          *  - The low address requirement is fulfilled.
 507          * else allocate non-contiguous pages if...
 508          *  - The page count that could get allocated doesn't exceed
 509          *    nsegments also when the maximum segment size is less
 510          *    than PAGE_SIZE.
 511          *  - The alignment constraint isn't larger than a page boundary.
 512          *  - There are no boundary-crossing constraints.
 513          * else allocate a block of contiguous pages because one or more of the
 514          * constraints is something that only the contig allocator can fulfill.
 515          *
 516          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 517          * below is just a quick hack. The exact alignment guarantees
 518          * of malloc(9) need to be nailed down, and the code below
 519          * should be rewritten to take that into account.
 520          *
 521          * In the meantime warn the user if malloc gets it wrong.
 522          */
 523         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 524            (dmat->common.alignment <= dmat->common.maxsize) &&
 525             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 526             attr == VM_MEMATTR_DEFAULT) {
 527                 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
 528         } else if (dmat->common.nsegments >=
 529             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
 530             dmat->common.alignment <= PAGE_SIZE &&
 531             (dmat->common.boundary % PAGE_SIZE) == 0) {
 532                 /* Page-based multi-segment allocations allowed */
 533                 *vaddr = (void *)kmem_alloc_attr(dmat->common.maxsize, mflags,
 534                     0ul, dmat->common.lowaddr, attr);
 535                 dmat->bounce_flags |= BF_KMEM_ALLOC;
 536         } else {
 537                 *vaddr = (void *)kmem_alloc_contig(dmat->common.maxsize, mflags,
 538                     0ul, dmat->common.lowaddr, dmat->common.alignment != 0 ?
 539                     dmat->common.alignment : 1ul, dmat->common.boundary, attr);
 540                 dmat->bounce_flags |= BF_KMEM_ALLOC;
 541         }
 542         if (*vaddr == NULL) {
 543                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 544                     __func__, dmat, dmat->common.flags, ENOMEM);
 545                 free(*mapp, M_DEVBUF);
 546                 return (ENOMEM);
 547         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 548                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 549         }
 550         dmat->map_count++;
 551         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 552             __func__, dmat, dmat->common.flags, 0);
 553         return (0);
 554 }
 555
 556 /*
 557  * Free a piece of memory and it's allociated dmamap, that was allocated
 558  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 559  */
 560 static void
 561 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 562 {
 563
 564         /*
 565          * Check the map came from bounce_bus_dmamem_alloc, so the map
 566          * should be NULL and the BF_KMEM_ALLOC flag cleared if malloc()
 567          * was used and set if kmem_alloc_contig() was used.
 568          */
 569         if ((map->flags & DMAMAP_FROM_DMAMEM) == 0)
 570                 panic("bus_dmamem_free: Invalid map freed\n");
 571         if ((dmat->bounce_flags & BF_KMEM_ALLOC) == 0)
 572                 free(vaddr, M_DEVBUF);
 573         else
 574                 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 575         free(map, M_DEVBUF);
 576         dmat->map_count--;
 577         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 578             dmat->bounce_flags);
 579 }
 580
 581 static bool
 582 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
 583     int *pagesneeded)
 584 {
 585         bus_addr_t curaddr;
 586         bus_size_t sgsize;
 587         int count;
 588
 589         /*
 590          * Count the number of bounce pages needed in order to
 591          * complete this transfer
 592          */
 593         count = 0;
 594         curaddr = buf;
 595         while (buflen != 0) {
 596                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 597                 if (must_bounce(dmat, curaddr)) {
 598                         sgsize = MIN(sgsize,
 599                             PAGE_SIZE - (curaddr & PAGE_MASK));
 600                         if (pagesneeded == NULL)
 601                                 return (true);
 602                         count++;
 603                 }
 604                 curaddr += sgsize;
 605                 buflen -= sgsize;
 606         }
 607
 608         if (pagesneeded != NULL)
 609                 *pagesneeded = count;
 610         return (count != 0);
 611 }
 612
 613 static void
 614 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 615     bus_size_t buflen, int flags)
 616 {
 617
 618         if (map->pagesneeded == 0) {
 619                 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
 620                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 621         }
 622 }
 623
 624 static void
 625 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 626     void *buf, bus_size_t buflen, int flags)
 627 {
 628         vm_offset_t vaddr;
 629         vm_offset_t vendaddr;
 630         bus_addr_t paddr;
 631         bus_size_t sg_len;
 632
 633         if (map->pagesneeded == 0) {
 634                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 635                     "alignment= %d", dmat->common.lowaddr,
 636                     ptoa((vm_paddr_t)Maxmem),
 637                     dmat->common.boundary, dmat->common.alignment);
 638                 CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d", map,
 639                     map->pagesneeded);
 640                 /*
 641                  * Count the number of bounce pages
 642                  * needed in order to complete this transfer
 643                  */
 644                 vaddr = (vm_offset_t)buf;
 645                 vendaddr = (vm_offset_t)buf + buflen;
 646
 647                 while (vaddr < vendaddr) {
 648                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 649                         if (pmap == kernel_pmap)
 650                                 paddr = pmap_kextract(vaddr);
 651                         else
 652                                 paddr = pmap_extract(pmap, vaddr);
 653                         if (must_bounce(dmat, paddr)) {
 654                                 sg_len = roundup2(sg_len,
 655                                     dmat->common.alignment);
 656                                 map->pagesneeded++;
 657                         }
 658                         vaddr += sg_len;
 659                 }
 660                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 661         }
 662 }
 663
 664 static int
 665 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 666 {
 667
 668         /* Reserve Necessary Bounce Pages */
 669         mtx_lock(&bounce_lock);
 670         if (flags & BUS_DMA_NOWAIT) {
 671                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 672                         mtx_unlock(&bounce_lock);
 673                         return (ENOMEM);
 674                 }
 675         } else {
 676                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 677                         /* Queue us for resources */
 678                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 679                         mtx_unlock(&bounce_lock);
 680                         return (EINPROGRESS);
 681                 }
 682         }
 683         mtx_unlock(&bounce_lock);
 684
 685         return (0);
 686 }
 687
 688 /*
 689  * Add a single contiguous physical range to the segment list.
 690  */
 691 static bus_size_t
 692 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 693     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 694 {
 695         bus_addr_t baddr, bmask;
 696         int seg;
 697
 698         /*
 699          * Make sure we don't cross any boundaries.
 700          */
 701         bmask = ~(dmat->common.boundary - 1);
 702         if (dmat->common.boundary > 0) {
 703                 baddr = (curaddr + dmat->common.boundary) & bmask;
 704                 if (sgsize > (baddr - curaddr))
 705                         sgsize = (baddr - curaddr);
 706         }
 707
 708         /*
 709          * Insert chunk into a segment, coalescing with
 710          * previous segment if possible.
 711          */
 712         seg = *segp;
 713         if (seg == -1) {
 714                 seg = 0;
 715                 segs[seg].ds_addr = curaddr;
 716                 segs[seg].ds_len = sgsize;
 717         } else {
 718                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 719                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 720                     (dmat->common.boundary == 0 ||
 721                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 722                         segs[seg].ds_len += sgsize;
 723                 else {
 724                         if (++seg >= dmat->common.nsegments)
 725                                 return (0);
 726                         segs[seg].ds_addr = curaddr;
 727                         segs[seg].ds_len = sgsize;
 728                 }
 729         }
 730         *segp = seg;
 731         return (sgsize);
 732 }
 733
 734 /*
 735  * Utility function to load a physical buffer.  segp contains
 736  * the starting segment on entrace, and the ending segment on exit.
 737  */
 738 static int
 739 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 740     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 741     int *segp)
 742 {
 743         struct sync_list *sl;
 744         bus_size_t sgsize;
 745         bus_addr_t curaddr, sl_end;
 746         int error;
 747
 748         if (segs == NULL)
 749                 segs = dmat->segments;
 750
 751         if (might_bounce(dmat)) {
 752                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 753                 if (map->pagesneeded != 0) {
 754                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 755                         if (error)
 756                                 return (error);
 757                 }
 758         }
 759
 760         sl = map->slist + map->sync_count - 1;
 761         sl_end = 0;
 762
 763         while (buflen > 0) {
 764                 curaddr = buf;
 765                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 766                 if (map->pagesneeded != 0 && must_bounce(dmat, curaddr)) {
 767                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 768                         curaddr = add_bounce_page(dmat, map, 0, curaddr,
 769                             sgsize);
 770                 } else if ((map->flags & DMAMAP_COHERENT) == 0) {
 771                         if (map->sync_count > 0)
 772                                 sl_end = sl->paddr + sl->datacount;
 773
 774                         if (map->sync_count == 0 || curaddr != sl_end) {
 775                                 if (++map->sync_count > dmat->common.nsegments)
 776                                         break;
 777                                 sl++;
 778                                 sl->vaddr = 0;
 779                                 sl->paddr = curaddr;
 780                                 sl->datacount = sgsize;
 781                                 sl->pages = PHYS_TO_VM_PAGE(curaddr);
 782                                 KASSERT(sl->pages != NULL,
 783                                     ("%s: page at PA:0x%08lx is not in "
 784                                     "vm_page_array", __func__, curaddr));
 785                         } else
 786                                 sl->datacount += sgsize;
 787                 }
 788                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 789                     segp);
 790                 if (sgsize == 0)
 791                         break;
 792                 buf += sgsize;
 793                 buflen -= sgsize;
 794         }
 795
 796         /*
 797          * Did we fit?
 798          */
 799         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 800 }
 801
 802 /*
 803  * Utility function to load a linear buffer.  segp contains
 804  * the starting segment on entrace, and the ending segment on exit.
 805  */
 806 static int
 807 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 808     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 809     int *segp)
 810 {
 811         struct sync_list *sl;
 812         bus_size_t sgsize, max_sgsize;
 813         bus_addr_t curaddr, sl_pend;
 814         vm_offset_t kvaddr, vaddr, sl_vend;
 815         int error;
 816
 817         if (segs == NULL)
 818                 segs = dmat->segments;
 819
 820         if (might_bounce(dmat)) {
 821                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 822                 if (map->pagesneeded != 0) {
 823                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 824                         if (error)
 825                                 return (error);
 826                 }
 827         }
 828
 829         sl = map->slist + map->sync_count - 1;
 830         vaddr = (vm_offset_t)buf;
 831         sl_pend = 0;
 832         sl_vend = 0;
 833
 834         while (buflen > 0) {
 835                 /*
 836                  * Get the physical address for this segment.
 837                  */
 838                 if (pmap == kernel_pmap) {
 839                         curaddr = pmap_kextract(vaddr);
 840                         kvaddr = vaddr;
 841                 } else {
 842                         curaddr = pmap_extract(pmap, vaddr);
 843                         kvaddr = 0;
 844                 }
 845
 846                 /*
 847                  * Compute the segment size, and adjust counts.
 848                  */
 849                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 850                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 851                 if (map->pagesneeded != 0 && must_bounce(dmat, curaddr)) {
 852                         sgsize = roundup2(sgsize, dmat->common.alignment);
 853                         sgsize = MIN(sgsize, max_sgsize);
 854                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr,
 855                             sgsize);
 856                 } else if ((map->flags & DMAMAP_COHERENT) == 0) {
 857                         sgsize = MIN(sgsize, max_sgsize);
 858                         if (map->sync_count > 0) {
 859                                 sl_pend = sl->paddr + sl->datacount;
 860                                 sl_vend = sl->vaddr + sl->datacount;
 861                         }
 862
 863                         if (map->sync_count == 0 ||
 864                             (kvaddr != 0 && kvaddr != sl_vend) ||
 865                             (curaddr != sl_pend)) {
 866                                 if (++map->sync_count > dmat->common.nsegments)
 867                                         goto cleanup;
 868                                 sl++;
 869                                 sl->vaddr = kvaddr;
 870                                 sl->paddr = curaddr;
 871                                 if (kvaddr != 0) {
 872                                         sl->pages = NULL;
 873                                 } else {
 874                                         sl->pages = PHYS_TO_VM_PAGE(curaddr);
 875                                         KASSERT(sl->pages != NULL,
 876                                             ("%s: page at PA:0x%08lx is not "
 877                                             "in vm_page_array", __func__,
 878                                             curaddr));
 879                                 }
 880                                 sl->datacount = sgsize;
 881                         } else
 882                                 sl->datacount += sgsize;
 883                 } else {
 884                         sgsize = MIN(sgsize, max_sgsize);
 885                 }
 886                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 887                     segp);
 888                 if (sgsize == 0)
 889                         break;
 890                 vaddr += sgsize;
 891                 buflen -= sgsize;
 892         }
 893
 894 cleanup:
 895         /*
 896          * Did we fit?
 897          */
 898         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 899 }
 900
 901 static void
 902 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 903     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 904 {
 905
 906         map->mem = *mem;
 907         map->dmat = dmat;
 908         map->callback = callback;
 909         map->callback_arg = callback_arg;
 910 }
 911
 912 static bus_dma_segment_t *
 913 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 914     bus_dma_segment_t *segs, int nsegs, int error)
 915 {
 916
 917         if (segs == NULL)
 918                 segs = dmat->segments;
 919         return (segs);
 920 }
 921
 922 /*
 923  * Release the mapping held by map.
 924  */
 925 static void
 926 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 927 {
 928         struct bounce_page *bpage;
 929
 930         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 931                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 932                 free_bounce_page(dmat, bpage);
 933         }
 934
 935         map->sync_count = 0;
 936 }
 937
 938 static void
 939 dma_preread_safe(vm_offset_t va, vm_size_t size)
 940 {
 941         /*
 942          * Write back any partial cachelines immediately before and
 943          * after the DMA region.
 944          */
 945         if (va & (dcache_line_size - 1))
 946                 cpu_dcache_wb_range(va, 1);
 947         if ((va + size) & (dcache_line_size - 1))
 948                 cpu_dcache_wb_range(va + size, 1);
 949
 950         cpu_dcache_inv_range(va, size);
 951 }
 952
 953 static void
 954 dma_dcache_sync(struct sync_list *sl, bus_dmasync_op_t op)
 955 {
 956         uint32_t len, offset;
 957         vm_page_t m;
 958         vm_paddr_t pa;
 959         vm_offset_t va, tempva;
 960         bus_size_t size;
 961
 962         offset = sl->paddr & PAGE_MASK;
 963         m = sl->pages;
 964         size = sl->datacount;
 965         pa = sl->paddr;
 966
 967         for ( ; size != 0; size -= len, pa += len, offset = 0, ++m) {
 968                 tempva = 0;
 969                 if (sl->vaddr == 0) {
 970                         len = min(PAGE_SIZE - offset, size);
 971                         tempva = pmap_quick_enter_page(m);
 972                         va = tempva | offset;
 973                         KASSERT(pa == (VM_PAGE_TO_PHYS(m) | offset),
 974                             ("unexpected vm_page_t phys: 0x%16lx != 0x%16lx",
 975                             VM_PAGE_TO_PHYS(m) | offset, pa));
 976                 } else {
 977                         len = sl->datacount;
 978                         va = sl->vaddr;
 979                 }
 980
 981                 switch (op) {
 982                 case BUS_DMASYNC_PREWRITE:
 983                 case BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD:
 984                         cpu_dcache_wb_range(va, len);
 985                         break;
 986                 case BUS_DMASYNC_PREREAD:
 987                         /*
 988                          * An mbuf may start in the middle of a cacheline. There
 989                          * will be no cpu writes to the beginning of that line
 990                          * (which contains the mbuf header) while dma is in
 991                          * progress.  Handle that case by doing a writeback of
 992                          * just the first cacheline before invalidating the
 993                          * overall buffer.  Any mbuf in a chain may have this
 994                          * misalignment.  Buffers which are not mbufs bounce if
 995                          * they are not aligned to a cacheline.
 996                          */
 997                         dma_preread_safe(va, len);
 998                         break;
 999                 case BUS_DMASYNC_POSTREAD:
1000                 case BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE:
1001                         cpu_dcache_inv_range(va, len);
1002                         break;
1003                 default:
1004                         panic("unsupported combination of sync operations: "
1005                               "0x%08x\n", op);
1006                 }
1007
1008                 if (tempva != 0)
1009                         pmap_quick_remove_page(tempva);
1010         }
1011 }
1012
1013 static void
1014 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
1015     bus_dmasync_op_t op)
1016 {
1017         struct bounce_page *bpage;
1018         struct sync_list *sl, *end;
1019         vm_offset_t datavaddr, tempvaddr;
1020
1021         if (op == BUS_DMASYNC_POSTWRITE)
1022                 return;
1023
1024         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1025                 /*
1026                  * Wait for any DMA operations to complete before the bcopy.
1027                  */
1028                 dsb(sy);
1029         }
1030
1031         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1032                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
1033                     "performing bounce", __func__, dmat, dmat->common.flags,
1034                     op);
1035
1036                 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
1037                         while (bpage != NULL) {
1038                                 tempvaddr = 0;
1039                                 datavaddr = bpage->datavaddr;
1040                                 if (datavaddr == 0) {
1041                                         tempvaddr = pmap_quick_enter_page(
1042                                             bpage->datapage);
1043                                         datavaddr = tempvaddr | bpage->dataoffs;
1044                                 }
1045
1046                                 bcopy((void *)datavaddr,
1047                                     (void *)bpage->vaddr, bpage->datacount);
1048                                 if (tempvaddr != 0)
1049                                         pmap_quick_remove_page(tempvaddr);
1050                                 if ((map->flags & DMAMAP_COHERENT) == 0)
1051                                         cpu_dcache_wb_range(bpage->vaddr,
1052                                             bpage->datacount);
1053                                 bpage = STAILQ_NEXT(bpage, links);
1054                         }
1055                         dmat->bounce_zone->total_bounced++;
1056                 } else if ((op & BUS_DMASYNC_PREREAD) != 0) {
1057                         while (bpage != NULL) {
1058                                 if ((map->flags & DMAMAP_COHERENT) == 0)
1059                                         cpu_dcache_wbinv_range(bpage->vaddr,
1060                                             bpage->datacount);
1061                                 bpage = STAILQ_NEXT(bpage, links);
1062                         }
1063                 }
1064
1065                 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1066                         while (bpage != NULL) {
1067                                 if ((map->flags & DMAMAP_COHERENT) == 0)
1068                                         cpu_dcache_inv_range(bpage->vaddr,
1069                                             bpage->datacount);
1070                                 tempvaddr = 0;
1071                                 datavaddr = bpage->datavaddr;
1072                                 if (datavaddr == 0) {
1073                                         tempvaddr = pmap_quick_enter_page(
1074                                             bpage->datapage);
1075                                         datavaddr = tempvaddr | bpage->dataoffs;
1076                                 }
1077
1078                                 bcopy((void *)bpage->vaddr,
1079                                     (void *)datavaddr, bpage->datacount);
1080
1081                                 if (tempvaddr != 0)
1082                                         pmap_quick_remove_page(tempvaddr);
1083                                 bpage = STAILQ_NEXT(bpage, links);
1084                         }
1085                         dmat->bounce_zone->total_bounced++;
1086                 }
1087         }
1088
1089         /*
1090          * Cache maintenance for normal (non-COHERENT non-bounce) buffers.
1091          */
1092         if (map->sync_count != 0) {
1093                 sl = &map->slist[0];
1094                 end = &map->slist[map->sync_count];
1095                 CTR3(KTR_BUSDMA, "%s: tag %p op 0x%x "
1096                     "performing sync", __func__, dmat, op);
1097
1098                 for ( ; sl != end; ++sl)
1099                         dma_dcache_sync(sl, op);
1100         }
1101
1102         if ((op & (BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE)) != 0) {
1103                 /*
1104                  * Wait for the bcopy to complete before any DMA operations.
1105                  */
1106                 dsb(sy);
1107         }
1108 }
1109
1110 static void
1111 init_bounce_pages(void *dummy __unused)
1112 {
1113
1114         total_bpages = 0;
1115         STAILQ_INIT(&bounce_zone_list);
1116         STAILQ_INIT(&bounce_map_waitinglist);
1117         STAILQ_INIT(&bounce_map_callbacklist);
1118         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1119 }
1120 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1121
1122 static struct sysctl_ctx_list *
1123 busdma_sysctl_tree(struct bounce_zone *bz)
1124 {
1125
1126         return (&bz->sysctl_tree);
1127 }
1128
1129 static struct sysctl_oid *
1130 busdma_sysctl_tree_top(struct bounce_zone *bz)
1131 {
1132
1133         return (bz->sysctl_tree_top);
1134 }
1135
1136 static int
1137 alloc_bounce_zone(bus_dma_tag_t dmat)
1138 {
1139         struct bounce_zone *bz;
1140
1141         /* Check to see if we already have a suitable zone */
1142         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1143                 if ((dmat->common.alignment <= bz->alignment) &&
1144                     (dmat->common.lowaddr >= bz->lowaddr)) {
1145                         dmat->bounce_zone = bz;
1146                         return (0);
1147                 }
1148         }
1149
1150         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1151             M_NOWAIT | M_ZERO)) == NULL)
1152                 return (ENOMEM);
1153
1154         STAILQ_INIT(&bz->bounce_page_list);
1155         bz->free_bpages = 0;
1156         bz->reserved_bpages = 0;
1157         bz->active_bpages = 0;
1158         bz->lowaddr = dmat->common.lowaddr;
1159         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1160         bz->map_count = 0;
1161         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1162         busdma_zonecount++;
1163         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1164         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1165         dmat->bounce_zone = bz;
1166
1167         sysctl_ctx_init(&bz->sysctl_tree);
1168         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1169             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1170             CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
1171         if (bz->sysctl_tree_top == NULL) {
1172                 sysctl_ctx_free(&bz->sysctl_tree);
1173                 return (0);     /* XXX error code? */
1174         }
1175
1176         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1177             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1178             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1179             "Total bounce pages");
1180         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1181             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1182             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1183             "Free bounce pages");
1184         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1185             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1186             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1187             "Reserved bounce pages");
1188         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1189             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1190             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1191             "Active bounce pages");
1192         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1193             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1194             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1195             "Total bounce requests");
1196         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1197             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1198             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1199             "Total bounce requests that were deferred");
1200         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1201             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1202             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1203         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1204             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1205             "alignment", CTLFLAG_RD, &bz->alignment, "");
1206
1207         return (0);
1208 }
1209
1210 static int
1211 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1212 {
1213         struct bounce_zone *bz;
1214         int count;
1215
1216         bz = dmat->bounce_zone;
1217         count = 0;
1218         while (numpages > 0) {
1219                 struct bounce_page *bpage;
1220
1221                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1222                                                      M_NOWAIT | M_ZERO);
1223
1224                 if (bpage == NULL)
1225                         break;
1226                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1227                     M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
1228                 if (bpage->vaddr == 0) {
1229                         free(bpage, M_DEVBUF);
1230                         break;
1231                 }
1232                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1233                 mtx_lock(&bounce_lock);
1234                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1235                 total_bpages++;
1236                 bz->total_bpages++;
1237                 bz->free_bpages++;
1238                 mtx_unlock(&bounce_lock);
1239                 count++;
1240                 numpages--;
1241         }
1242         return (count);
1243 }
1244
1245 static int
1246 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1247 {
1248         struct bounce_zone *bz;
1249         int pages;
1250
1251         mtx_assert(&bounce_lock, MA_OWNED);
1252         bz = dmat->bounce_zone;
1253         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1254         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1255                 return (map->pagesneeded - (map->pagesreserved + pages));
1256         bz->free_bpages -= pages;
1257         bz->reserved_bpages += pages;
1258         map->pagesreserved += pages;
1259         pages = map->pagesneeded - map->pagesreserved;
1260
1261         return (pages);
1262 }
1263
1264 static bus_addr_t
1265 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1266                 bus_addr_t addr, bus_size_t size)
1267 {
1268         struct bounce_zone *bz;
1269         struct bounce_page *bpage;
1270
1271         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1272
1273         bz = dmat->bounce_zone;
1274         if (map->pagesneeded == 0)
1275                 panic("add_bounce_page: map doesn't need any pages");
1276         map->pagesneeded--;
1277
1278         if (map->pagesreserved == 0)
1279                 panic("add_bounce_page: map doesn't need any pages");
1280         map->pagesreserved--;
1281
1282         mtx_lock(&bounce_lock);
1283         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1284         if (bpage == NULL)
1285                 panic("add_bounce_page: free page list is empty");
1286
1287         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1288         bz->reserved_bpages--;
1289         bz->active_bpages++;
1290         mtx_unlock(&bounce_lock);
1291
1292         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1293                 /* Page offset needs to be preserved. */
1294                 bpage->vaddr |= addr & PAGE_MASK;
1295                 bpage->busaddr |= addr & PAGE_MASK;
1296         }
1297         bpage->datavaddr = vaddr;
1298         bpage->datapage = PHYS_TO_VM_PAGE(addr);
1299         bpage->dataoffs = addr & PAGE_MASK;
1300         bpage->datacount = size;
1301         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1302         return (bpage->busaddr);
1303 }
1304
1305 static void
1306 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1307 {
1308         struct bus_dmamap *map;
1309         struct bounce_zone *bz;
1310
1311         bz = dmat->bounce_zone;
1312         bpage->datavaddr = 0;
1313         bpage->datacount = 0;
1314         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1315                 /*
1316                  * Reset the bounce page to start at offset 0.  Other uses
1317                  * of this bounce page may need to store a full page of
1318                  * data and/or assume it starts on a page boundary.
1319                  */
1320                 bpage->vaddr &= ~PAGE_MASK;
1321                 bpage->busaddr &= ~PAGE_MASK;
1322         }
1323
1324         mtx_lock(&bounce_lock);
1325         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1326         bz->free_bpages++;
1327         bz->active_bpages--;
1328         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1329                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1330                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1331                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1332                             map, links);
1333                         busdma_swi_pending = 1;
1334                         bz->total_deferred++;
1335                         swi_sched(vm_ih, 0);
1336                 }
1337         }
1338         mtx_unlock(&bounce_lock);
1339 }
1340
1341 void
1342 busdma_swi(void)
1343 {
1344         bus_dma_tag_t dmat;
1345         struct bus_dmamap *map;
1346
1347         mtx_lock(&bounce_lock);
1348         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1349                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1350                 mtx_unlock(&bounce_lock);
1351                 dmat = map->dmat;
1352                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1353                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1354                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1355                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1356                     BUS_DMA_UNLOCK);
1357                 mtx_lock(&bounce_lock);
1358         }
1359         mtx_unlock(&bounce_lock);
1360 }
1361
1362 struct bus_dma_impl bus_dma_bounce_impl = {
1363         .tag_create = bounce_bus_dma_tag_create,
1364         .tag_destroy = bounce_bus_dma_tag_destroy,
1365         .id_mapped = bounce_bus_dma_id_mapped,
1366         .map_create = bounce_bus_dmamap_create,
1367         .map_destroy = bounce_bus_dmamap_destroy,
1368         .mem_alloc = bounce_bus_dmamem_alloc,
1369         .mem_free = bounce_bus_dmamem_free,
1370         .load_phys = bounce_bus_dmamap_load_phys,
1371         .load_buffer = bounce_bus_dmamap_load_buffer,
1372         .load_ma = bus_dmamap_load_ma_triv,
1373         .map_waitok = bounce_bus_dmamap_waitok,
1374         .map_complete = bounce_bus_dmamap_complete,
1375         .map_unload = bounce_bus_dmamap_unload,
1376         .map_sync = bounce_bus_dmamap_sync
1377 };