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