sys/x86/x86/busdma_bounce.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1997, 1998 Justin T. Gibbs.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions, and the following disclaimer,
  12  *    without modification, immediately at the beginning of the file.
  13  * 2. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/systm.h>
  34 #include <sys/domainset.h>
  35 #include <sys/malloc.h>
  36 #include <sys/bus.h>
  37 #include <sys/interrupt.h>
  38 #include <sys/kernel.h>
  39 #include <sys/ktr.h>
  40 #include <sys/lock.h>
  41 #include <sys/proc.h>
  42 #include <sys/memdesc.h>
  43 #include <sys/mutex.h>
  44 #include <sys/sysctl.h>
  45 #include <sys/uio.h>
  46
  47 #include <vm/vm.h>
  48 #include <vm/vm_extern.h>
  49 #include <vm/vm_kern.h>
  50 #include <vm/vm_page.h>
  51 #include <vm/vm_map.h>
  52
  53 #include <machine/atomic.h>
  54 #include <machine/bus.h>
  55 #include <machine/md_var.h>
  56 #include <machine/specialreg.h>
  57 #include <x86/include/busdma_impl.h>
  58
  59 #ifdef __i386__
  60 #define MAX_BPAGES (Maxmem > atop(0x100000000ULL) ? 8192 : 512)
  61 #else
  62 #define MAX_BPAGES 8192
  63 #endif
  64
  65 enum {
  66         BUS_DMA_COULD_BOUNCE    = 0x01,
  67         BUS_DMA_MIN_ALLOC_COMP  = 0x02,
  68         BUS_DMA_KMEM_ALLOC      = 0x04,
  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_offset_t     dataoffs;       /* page offset of client data */
  86         vm_page_t       datapage[2];    /* physical page(s) 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         int             domain;
 104         bus_size_t      alignment;
 105         bus_addr_t      lowaddr;
 106         char            zoneid[8];
 107         char            lowaddrid[20];
 108         struct sysctl_ctx_list sysctl_tree;
 109         struct sysctl_oid *sysctl_tree_top;
 110 };
 111
 112 static struct mtx bounce_lock;
 113 static int total_bpages;
 114 static int busdma_zonecount;
 115 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
 116
 117 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
 118     "Busdma parameters");
 119 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 120            "Total bounce pages");
 121
 122 struct bus_dmamap {
 123         struct bp_list         bpages;
 124         int                    pagesneeded;
 125         int                    pagesreserved;
 126         bus_dma_tag_t          dmat;
 127         struct memdesc         mem;
 128         bus_dmamap_callback_t *callback;
 129         void                  *callback_arg;
 130         STAILQ_ENTRY(bus_dmamap) links;
 131 };
 132
 133 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 134 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 135 static struct bus_dmamap nobounce_dmamap;
 136
 137 static void init_bounce_pages(void *dummy);
 138 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 139 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 140 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 141     int commit);
 142 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 143     vm_offset_t vaddr, vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size);
 144 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 145 static bool _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf,
 146     bus_size_t buflen, int *pagesneeded);
 147 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 148     pmap_t pmap, void *buf, bus_size_t buflen, int flags);
 149 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 150     vm_paddr_t buf, bus_size_t buflen, int flags);
 151 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 152     int flags);
 153
 154 static int
 155 bounce_bus_dma_zone_setup(bus_dma_tag_t dmat)
 156 {
 157         struct bounce_zone *bz;
 158         int error;
 159
 160         /* Must bounce */
 161         if ((error = alloc_bounce_zone(dmat)) != 0)
 162                 return (error);
 163         bz = dmat->bounce_zone;
 164
 165         if (ptoa(bz->total_bpages) < dmat->common.maxsize) {
 166                 int pages;
 167
 168                 pages = atop(dmat->common.maxsize) - bz->total_bpages;
 169
 170                 /* Add pages to our bounce pool */
 171                 if (alloc_bounce_pages(dmat, pages) < pages)
 172                         return (ENOMEM);
 173         }
 174         /* Performed initial allocation */
 175         dmat->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 176
 177         return (0);
 178 }
 179
 180 /*
 181  * Allocate a device specific dma_tag.
 182  */
 183 static int
 184 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 185     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 186     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 187     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 188     void *lockfuncarg, bus_dma_tag_t *dmat)
 189 {
 190         bus_dma_tag_t newtag;
 191         int error;
 192
 193         *dmat = NULL;
 194         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 195             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 196             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 197             sizeof (struct bus_dma_tag), (void **)&newtag);
 198         if (error != 0)
 199                 return (error);
 200
 201         newtag->common.impl = &bus_dma_bounce_impl;
 202         newtag->map_count = 0;
 203         newtag->segments = NULL;
 204
 205         if (parent != NULL && (newtag->common.filter != NULL ||
 206             (parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0))
 207                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 208
 209         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 210             newtag->common.alignment > 1)
 211                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 212
 213         if ((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 214             (flags & BUS_DMA_ALLOCNOW) != 0)
 215                 error = bounce_bus_dma_zone_setup(newtag);
 216         else
 217                 error = 0;
 218
 219         if (error != 0)
 220                 free(newtag, M_DEVBUF);
 221         else
 222                 *dmat = newtag;
 223         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 224             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 225             error);
 226         return (error);
 227 }
 228
 229 static bool
 230 bounce_bus_dma_id_mapped(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen)
 231 {
 232
 233         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0)
 234                 return (true);
 235         return (!_bus_dmamap_pagesneeded(dmat, buf, buflen, NULL));
 236 }
 237
 238 /*
 239  * Update the domain for the tag.  We may need to reallocate the zone and
 240  * bounce pages.
 241  */
 242 static int
 243 bounce_bus_dma_tag_set_domain(bus_dma_tag_t dmat)
 244 {
 245
 246         KASSERT(dmat->map_count == 0,
 247             ("bounce_bus_dma_tag_set_domain:  Domain set after use.\n"));
 248         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0 ||
 249             dmat->bounce_zone == NULL)
 250                 return (0);
 251         dmat->bounce_flags &= ~BUS_DMA_MIN_ALLOC_COMP;
 252         return (bounce_bus_dma_zone_setup(dmat));
 253 }
 254
 255 static int
 256 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 257 {
 258         bus_dma_tag_t dmat_copy, parent;
 259         int error;
 260
 261         error = 0;
 262         dmat_copy = dmat;
 263
 264         if (dmat != NULL) {
 265                 if (dmat->map_count != 0) {
 266                         error = EBUSY;
 267                         goto out;
 268                 }
 269                 while (dmat != NULL) {
 270                         parent = (bus_dma_tag_t)dmat->common.parent;
 271                         atomic_subtract_int(&dmat->common.ref_count, 1);
 272                         if (dmat->common.ref_count == 0) {
 273                                 if (dmat->segments != NULL)
 274                                         free(dmat->segments, M_DEVBUF);
 275                                 free(dmat, M_DEVBUF);
 276                                 /*
 277                                  * Last reference count, so
 278                                  * release our reference
 279                                  * count on our parent.
 280                                  */
 281                                 dmat = parent;
 282                         } else
 283                                 dmat = NULL;
 284                 }
 285         }
 286 out:
 287         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 288         return (error);
 289 }
 290
 291 /*
 292  * Allocate a handle for mapping from kva/uva/physical
 293  * address space into bus device space.
 294  */
 295 static int
 296 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 297 {
 298         struct bounce_zone *bz;
 299         int error, maxpages, pages;
 300
 301         error = 0;
 302
 303         if (dmat->segments == NULL) {
 304                 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
 305                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 306                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT);
 307                 if (dmat->segments == NULL) {
 308                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 309                             __func__, dmat, ENOMEM);
 310                         return (ENOMEM);
 311                 }
 312         }
 313
 314         /*
 315          * Bouncing might be required if the driver asks for an active
 316          * exclusion region, a data alignment that is stricter than 1, and/or
 317          * an active address boundary.
 318          */
 319         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 320                 /* Must bounce */
 321                 if (dmat->bounce_zone == NULL) {
 322                         if ((error = alloc_bounce_zone(dmat)) != 0)
 323                                 return (error);
 324                 }
 325                 bz = dmat->bounce_zone;
 326
 327                 *mapp = (bus_dmamap_t)malloc_domainset(sizeof(**mapp), M_DEVBUF,
 328                     DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
 329                 if (*mapp == NULL) {
 330                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 331                             __func__, dmat, ENOMEM);
 332                         return (ENOMEM);
 333                 }
 334
 335                 /* Initialize the new map */
 336                 STAILQ_INIT(&((*mapp)->bpages));
 337
 338                 /*
 339                  * Attempt to add pages to our pool on a per-instance
 340                  * basis up to a sane limit.
 341                  */
 342                 if (dmat->common.alignment > 1)
 343                         maxpages = MAX_BPAGES;
 344                 else
 345                         maxpages = MIN(MAX_BPAGES, Maxmem -
 346                             atop(dmat->common.lowaddr));
 347                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 348                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 349                         pages = MAX(atop(dmat->common.maxsize), 1);
 350                         pages = MIN(maxpages - bz->total_bpages, pages);
 351                         pages = MAX(pages, 1);
 352                         if (alloc_bounce_pages(dmat, pages) < pages)
 353                                 error = ENOMEM;
 354                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 355                             == 0) {
 356                                 if (error == 0) {
 357                                         dmat->bounce_flags |=
 358                                             BUS_DMA_MIN_ALLOC_COMP;
 359                                 }
 360                         } else
 361                                 error = 0;
 362                 }
 363                 bz->map_count++;
 364         } else {
 365                 *mapp = NULL;
 366         }
 367         if (error == 0)
 368                 dmat->map_count++;
 369         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 370             __func__, dmat, dmat->common.flags, error);
 371         return (error);
 372 }
 373
 374 /*
 375  * Destroy a handle for mapping from kva/uva/physical
 376  * address space into bus device space.
 377  */
 378 static int
 379 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 380 {
 381
 382         if (map != NULL && map != &nobounce_dmamap) {
 383                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 384                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 385                             __func__, dmat, EBUSY);
 386                         return (EBUSY);
 387                 }
 388                 if (dmat->bounce_zone)
 389                         dmat->bounce_zone->map_count--;
 390                 free(map, M_DEVBUF);
 391         }
 392         dmat->map_count--;
 393         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 394         return (0);
 395 }
 396
 397
 398 /*
 399  * Allocate a piece of memory that can be efficiently mapped into
 400  * bus device space based on the constraints lited in the dma tag.
 401  * A dmamap to for use with dmamap_load is also allocated.
 402  */
 403 static int
 404 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 405     bus_dmamap_t *mapp)
 406 {
 407         vm_memattr_t attr;
 408         int mflags;
 409
 410         if (flags & BUS_DMA_NOWAIT)
 411                 mflags = M_NOWAIT;
 412         else
 413                 mflags = M_WAITOK;
 414
 415         /* If we succeed, no mapping/bouncing will be required */
 416         *mapp = NULL;
 417
 418         if (dmat->segments == NULL) {
 419                 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
 420                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 421                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), mflags);
 422                 if (dmat->segments == NULL) {
 423                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 424                             __func__, dmat, dmat->common.flags, ENOMEM);
 425                         return (ENOMEM);
 426                 }
 427         }
 428         if (flags & BUS_DMA_ZERO)
 429                 mflags |= M_ZERO;
 430         if (flags & BUS_DMA_NOCACHE)
 431                 attr = VM_MEMATTR_UNCACHEABLE;
 432         else
 433                 attr = VM_MEMATTR_DEFAULT;
 434
 435         /*
 436          * Allocate the buffer from the malloc(9) allocator if...
 437          *  - It's small enough to fit into a single power of two sized bucket.
 438          *  - The alignment is less than or equal to the maximum size
 439          *  - The low address requirement is fulfilled.
 440          * else allocate non-contiguous pages if...
 441          *  - The page count that could get allocated doesn't exceed
 442          *    nsegments also when the maximum segment size is less
 443          *    than PAGE_SIZE.
 444          *  - The alignment constraint isn't larger than a page boundary.
 445          *  - There are no boundary-crossing constraints.
 446          * else allocate a block of contiguous pages because one or more of the
 447          * constraints is something that only the contig allocator can fulfill.
 448          *
 449          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 450          * below is just a quick hack. The exact alignment guarantees
 451          * of malloc(9) need to be nailed down, and the code below
 452          * should be rewritten to take that into account.
 453          *
 454          * In the meantime warn the user if malloc gets it wrong.
 455          */
 456         if (dmat->common.maxsize <= PAGE_SIZE &&
 457             dmat->common.alignment <= dmat->common.maxsize &&
 458             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 459             attr == VM_MEMATTR_DEFAULT) {
 460                 *vaddr = malloc_domainset(dmat->common.maxsize, M_DEVBUF,
 461                     DOMAINSET_PREF(dmat->common.domain), mflags);
 462         } else if (dmat->common.nsegments >=
 463             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz,
 464             PAGE_SIZE)) &&
 465             dmat->common.alignment <= PAGE_SIZE &&
 466             (dmat->common.boundary % PAGE_SIZE) == 0) {
 467                 /* Page-based multi-segment allocations allowed */
 468                 *vaddr = (void *)kmem_alloc_attr_domainset(
 469                     DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
 470                     mflags, 0ul, dmat->common.lowaddr, attr);
 471                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 472         } else {
 473                 *vaddr = (void *)kmem_alloc_contig_domainset(
 474                     DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
 475                     mflags, 0ul, dmat->common.lowaddr,
 476                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 477                     dmat->common.boundary, attr);
 478                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 479         }
 480         if (*vaddr == NULL) {
 481                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 482                     __func__, dmat, dmat->common.flags, ENOMEM);
 483                 return (ENOMEM);
 484         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 485                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 486         }
 487         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 488             __func__, dmat, dmat->common.flags, 0);
 489         return (0);
 490 }
 491
 492 /*
 493  * Free a piece of memory and its associated dmamap, that was allocated
 494  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 495  */
 496 static void
 497 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 498 {
 499         /*
 500          * dmamem does not need to be bounced, so the map should be
 501          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 502          * was used and set if kmem_alloc_contig() was used.
 503          */
 504         if (map != NULL)
 505                 panic("bus_dmamem_free: Invalid map freed\n");
 506         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 507                 free(vaddr, M_DEVBUF);
 508         else
 509                 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 510         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 511             dmat->bounce_flags);
 512 }
 513
 514 static bool
 515 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
 516     int *pagesneeded)
 517 {
 518         vm_paddr_t curaddr;
 519         bus_size_t sgsize;
 520         int count;
 521
 522         /*
 523          * Count the number of bounce pages needed in order to
 524          * complete this transfer
 525          */
 526         count = 0;
 527         curaddr = buf;
 528         while (buflen != 0) {
 529                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 530                 if (bus_dma_run_filter(&dmat->common, curaddr)) {
 531                         sgsize = MIN(sgsize,
 532                             PAGE_SIZE - (curaddr & PAGE_MASK));
 533                         if (pagesneeded == NULL)
 534                                 return (true);
 535                         count++;
 536                 }
 537                 curaddr += sgsize;
 538                 buflen -= sgsize;
 539         }
 540
 541         if (pagesneeded != NULL)
 542                 *pagesneeded = count;
 543         return (count != 0);
 544 }
 545
 546 static void
 547 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 548     bus_size_t buflen, int flags)
 549 {
 550
 551         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 552                 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
 553                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 554         }
 555 }
 556
 557 static void
 558 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 559     void *buf, bus_size_t buflen, int flags)
 560 {
 561         vm_offset_t vaddr;
 562         vm_offset_t vendaddr;
 563         vm_paddr_t paddr;
 564         bus_size_t sg_len;
 565
 566         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 567                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 568                     "alignment= %d", dmat->common.lowaddr,
 569                     ptoa((vm_paddr_t)Maxmem),
 570                     dmat->common.boundary, dmat->common.alignment);
 571                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 572                     map, &nobounce_dmamap, map->pagesneeded);
 573                 /*
 574                  * Count the number of bounce pages
 575                  * needed in order to complete this transfer
 576                  */
 577                 vaddr = (vm_offset_t)buf;
 578                 vendaddr = (vm_offset_t)buf + buflen;
 579
 580                 while (vaddr < vendaddr) {
 581                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 582                         if (pmap == kernel_pmap)
 583                                 paddr = pmap_kextract(vaddr);
 584                         else
 585                                 paddr = pmap_extract(pmap, vaddr);
 586                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 587                                 sg_len = roundup2(sg_len,
 588                                     dmat->common.alignment);
 589                                 map->pagesneeded++;
 590                         }
 591                         vaddr += sg_len;
 592                 }
 593                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 594         }
 595 }
 596
 597 static void
 598 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 599     int ma_offs, bus_size_t buflen, int flags)
 600 {
 601         bus_size_t sg_len, max_sgsize;
 602         int page_index;
 603         vm_paddr_t paddr;
 604
 605         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 606                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 607                     "alignment= %d", dmat->common.lowaddr,
 608                     ptoa((vm_paddr_t)Maxmem),
 609                     dmat->common.boundary, dmat->common.alignment);
 610                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 611                     map, &nobounce_dmamap, map->pagesneeded);
 612
 613                 /*
 614                  * Count the number of bounce pages
 615                  * needed in order to complete this transfer
 616                  */
 617                 page_index = 0;
 618                 while (buflen > 0) {
 619                         paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 620                         sg_len = PAGE_SIZE - ma_offs;
 621                         max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 622                         sg_len = MIN(sg_len, max_sgsize);
 623                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 624                                 sg_len = roundup2(sg_len,
 625                                     dmat->common.alignment);
 626                                 sg_len = MIN(sg_len, max_sgsize);
 627                                 KASSERT((sg_len & (dmat->common.alignment - 1))
 628                                     == 0, ("Segment size is not aligned"));
 629                                 map->pagesneeded++;
 630                         }
 631                         if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
 632                                 page_index++;
 633                         ma_offs = (ma_offs + sg_len) & PAGE_MASK;
 634                         KASSERT(buflen >= sg_len,
 635                             ("Segment length overruns original buffer"));
 636                         buflen -= sg_len;
 637                 }
 638                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 639         }
 640 }
 641
 642 static int
 643 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 644 {
 645
 646         /* Reserve Necessary Bounce Pages */
 647         mtx_lock(&bounce_lock);
 648         if (flags & BUS_DMA_NOWAIT) {
 649                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 650                         mtx_unlock(&bounce_lock);
 651                         return (ENOMEM);
 652                 }
 653         } else {
 654                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 655                         /* Queue us for resources */
 656                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 657                         mtx_unlock(&bounce_lock);
 658                         return (EINPROGRESS);
 659                 }
 660         }
 661         mtx_unlock(&bounce_lock);
 662
 663         return (0);
 664 }
 665
 666 /*
 667  * Add a single contiguous physical range to the segment list.
 668  */
 669 static bus_size_t
 670 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t curaddr,
 671     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 672 {
 673         bus_addr_t baddr, bmask;
 674         int seg;
 675
 676         KASSERT(curaddr <= BUS_SPACE_MAXADDR,
 677             ("ds_addr %#jx > BUS_SPACE_MAXADDR %#jx; dmat %p fl %#x low %#jx "
 678             "hi %#jx",
 679             (uintmax_t)curaddr, (uintmax_t)BUS_SPACE_MAXADDR,
 680             dmat, dmat->bounce_flags, (uintmax_t)dmat->common.lowaddr,
 681             (uintmax_t)dmat->common.highaddr));
 682
 683         /*
 684          * Make sure we don't cross any boundaries.
 685          */
 686         bmask = ~(dmat->common.boundary - 1);
 687         if (dmat->common.boundary > 0) {
 688                 baddr = (curaddr + dmat->common.boundary) & bmask;
 689                 if (sgsize > (baddr - curaddr))
 690                         sgsize = (baddr - curaddr);
 691         }
 692
 693         /*
 694          * Insert chunk into a segment, coalescing with
 695          * previous segment if possible.
 696          */
 697         seg = *segp;
 698         if (seg == -1) {
 699                 seg = 0;
 700                 segs[seg].ds_addr = curaddr;
 701                 segs[seg].ds_len = sgsize;
 702         } else {
 703                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 704                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 705                     (dmat->common.boundary == 0 ||
 706                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 707                         segs[seg].ds_len += sgsize;
 708                 else {
 709                         if (++seg >= dmat->common.nsegments)
 710                                 return (0);
 711                         segs[seg].ds_addr = curaddr;
 712                         segs[seg].ds_len = sgsize;
 713                 }
 714         }
 715         *segp = seg;
 716         return (sgsize);
 717 }
 718
 719 /*
 720  * Utility function to load a physical buffer.  segp contains
 721  * the starting segment on entrace, and the ending segment on exit.
 722  */
 723 static int
 724 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 725     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 726     int *segp)
 727 {
 728         bus_size_t sgsize;
 729         vm_paddr_t curaddr;
 730         int error;
 731
 732         if (map == NULL)
 733                 map = &nobounce_dmamap;
 734
 735         if (segs == NULL)
 736                 segs = dmat->segments;
 737
 738         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 739                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 740                 if (map->pagesneeded != 0) {
 741                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 742                         if (error)
 743                                 return (error);
 744                 }
 745         }
 746
 747         while (buflen > 0) {
 748                 curaddr = buf;
 749                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 750                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 751                     map->pagesneeded != 0 &&
 752                     bus_dma_run_filter(&dmat->common, curaddr)) {
 753                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 754                         curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
 755                             sgsize);
 756                 }
 757                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 758                     segp);
 759                 if (sgsize == 0)
 760                         break;
 761                 buf += sgsize;
 762                 buflen -= sgsize;
 763         }
 764
 765         /*
 766          * Did we fit?
 767          */
 768         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 769 }
 770
 771 /*
 772  * Utility function to load a linear buffer.  segp contains
 773  * the starting segment on entrace, and the ending segment on exit.
 774  */
 775 static int
 776 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 777     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 778     int *segp)
 779 {
 780         bus_size_t sgsize, max_sgsize;
 781         vm_paddr_t curaddr;
 782         vm_offset_t kvaddr, vaddr;
 783         int error;
 784
 785         if (map == NULL)
 786                 map = &nobounce_dmamap;
 787
 788         if (segs == NULL)
 789                 segs = dmat->segments;
 790
 791         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 792                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 793                 if (map->pagesneeded != 0) {
 794                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 795                         if (error)
 796                                 return (error);
 797                 }
 798         }
 799
 800         vaddr = (vm_offset_t)buf;
 801         while (buflen > 0) {
 802                 /*
 803                  * Get the physical address for this segment.
 804                  */
 805                 if (pmap == kernel_pmap) {
 806                         curaddr = pmap_kextract(vaddr);
 807                         kvaddr = vaddr;
 808                 } else {
 809                         curaddr = pmap_extract(pmap, vaddr);
 810                         kvaddr = 0;
 811                 }
 812
 813                 /*
 814                  * Compute the segment size, and adjust counts.
 815                  */
 816                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 817                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 818                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 819                     map->pagesneeded != 0 &&
 820                     bus_dma_run_filter(&dmat->common, curaddr)) {
 821                         sgsize = roundup2(sgsize, dmat->common.alignment);
 822                         sgsize = MIN(sgsize, max_sgsize);
 823                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 824                             sgsize);
 825                 } else {
 826                         sgsize = MIN(sgsize, max_sgsize);
 827                 }
 828                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 829                     segp);
 830                 if (sgsize == 0)
 831                         break;
 832                 vaddr += sgsize;
 833                 buflen -= sgsize;
 834         }
 835
 836         /*
 837          * Did we fit?
 838          */
 839         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 840 }
 841
 842 static int
 843 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 844     struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
 845     bus_dma_segment_t *segs, int *segp)
 846 {
 847         vm_paddr_t paddr, next_paddr;
 848         int error, page_index;
 849         bus_size_t sgsize, max_sgsize;
 850
 851         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 852                 /*
 853                  * If we have to keep the offset of each page this function
 854                  * is not suitable, switch back to bus_dmamap_load_ma_triv
 855                  * which is going to do the right thing in this case.
 856                  */
 857                 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
 858                     flags, segs, segp);
 859                 return (error);
 860         }
 861
 862         if (map == NULL)
 863                 map = &nobounce_dmamap;
 864
 865         if (segs == NULL)
 866                 segs = dmat->segments;
 867
 868         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 869                 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
 870                 if (map->pagesneeded != 0) {
 871                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 872                         if (error)
 873                                 return (error);
 874                 }
 875         }
 876
 877         page_index = 0;
 878         while (buflen > 0) {
 879                 /*
 880                  * Compute the segment size, and adjust counts.
 881                  */
 882                 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 883                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 884                 sgsize = PAGE_SIZE - ma_offs;
 885                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 886                     map->pagesneeded != 0 &&
 887                     bus_dma_run_filter(&dmat->common, paddr)) {
 888                         sgsize = roundup2(sgsize, dmat->common.alignment);
 889                         sgsize = MIN(sgsize, max_sgsize);
 890                         KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
 891                             ("Segment size is not aligned"));
 892                         /*
 893                          * Check if two pages of the user provided buffer
 894                          * are used.
 895                          */
 896                         if ((ma_offs + sgsize) > PAGE_SIZE)
 897                                 next_paddr =
 898                                     VM_PAGE_TO_PHYS(ma[page_index + 1]);
 899                         else
 900                                 next_paddr = 0;
 901                         paddr = add_bounce_page(dmat, map, 0, paddr,
 902                             next_paddr, sgsize);
 903                 } else {
 904                         sgsize = MIN(sgsize, max_sgsize);
 905                 }
 906                 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
 907                     segp);
 908                 if (sgsize == 0)
 909                         break;
 910                 KASSERT(buflen >= sgsize,
 911                     ("Segment length overruns original buffer"));
 912                 buflen -= sgsize;
 913                 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
 914                         page_index++;
 915                 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
 916         }
 917
 918         /*
 919          * Did we fit?
 920          */
 921         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 922 }
 923
 924 static void
 925 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 926     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 927 {
 928
 929         if (map == NULL)
 930                 return;
 931         map->mem = *mem;
 932         map->dmat = dmat;
 933         map->callback = callback;
 934         map->callback_arg = callback_arg;
 935 }
 936
 937 static bus_dma_segment_t *
 938 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 939     bus_dma_segment_t *segs, int nsegs, int error)
 940 {
 941
 942         if (segs == NULL)
 943                 segs = dmat->segments;
 944         return (segs);
 945 }
 946
 947 /*
 948  * Release the mapping held by map.
 949  */
 950 static void
 951 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 952 {
 953         struct bounce_page *bpage;
 954
 955         if (map == NULL)
 956                 return;
 957
 958         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 959                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 960                 free_bounce_page(dmat, bpage);
 961         }
 962 }
 963
 964 static void
 965 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 966     bus_dmasync_op_t op)
 967 {
 968         struct bounce_page *bpage;
 969         vm_offset_t datavaddr, tempvaddr;
 970         bus_size_t datacount1, datacount2;
 971
 972         if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 973                 return;
 974
 975         /*
 976          * Handle data bouncing.  We might also want to add support for
 977          * invalidating the caches on broken hardware.
 978          */
 979         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 980             "performing bounce", __func__, dmat, dmat->common.flags, op);
 981
 982         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 983                 while (bpage != NULL) {
 984                         tempvaddr = 0;
 985                         datavaddr = bpage->datavaddr;
 986                         datacount1 = bpage->datacount;
 987                         if (datavaddr == 0) {
 988                                 tempvaddr =
 989                                     pmap_quick_enter_page(bpage->datapage[0]);
 990                                 datavaddr = tempvaddr | bpage->dataoffs;
 991                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 992                                     datacount1);
 993                         }
 994
 995                         bcopy((void *)datavaddr,
 996                             (void *)bpage->vaddr, datacount1);
 997
 998                         if (tempvaddr != 0)
 999                                 pmap_quick_remove_page(tempvaddr);
1000
1001                         if (bpage->datapage[1] == 0) {
1002                                 KASSERT(datacount1 == bpage->datacount,
1003                 ("Mismatch between data size and provided memory space"));
1004                                 goto next_w;
1005                         }
1006
1007                         /*
1008                          * We are dealing with an unmapped buffer that expands
1009                          * over two pages.
1010                          */
1011                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1012                         datacount2 = bpage->datacount - datacount1;
1013                         bcopy((void *)datavaddr,
1014                             (void *)(bpage->vaddr + datacount1), datacount2);
1015                         pmap_quick_remove_page(datavaddr);
1016
1017 next_w:
1018                         bpage = STAILQ_NEXT(bpage, links);
1019                 }
1020                 dmat->bounce_zone->total_bounced++;
1021         }
1022
1023         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1024                 while (bpage != NULL) {
1025                         tempvaddr = 0;
1026                         datavaddr = bpage->datavaddr;
1027                         datacount1 = bpage->datacount;
1028                         if (datavaddr == 0) {
1029                                 tempvaddr =
1030                                     pmap_quick_enter_page(bpage->datapage[0]);
1031                                 datavaddr = tempvaddr | bpage->dataoffs;
1032                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
1033                                     datacount1);
1034                         }
1035
1036                         bcopy((void *)bpage->vaddr, (void *)datavaddr,
1037                             datacount1);
1038
1039                         if (tempvaddr != 0)
1040                                 pmap_quick_remove_page(tempvaddr);
1041
1042                         if (bpage->datapage[1] == 0) {
1043                                 KASSERT(datacount1 == bpage->datacount,
1044                 ("Mismatch between data size and provided memory space"));
1045                                 goto next_r;
1046                         }
1047
1048                         /*
1049                          * We are dealing with an unmapped buffer that expands
1050                          * over two pages.
1051                          */
1052                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1053                         datacount2 = bpage->datacount - datacount1;
1054                         bcopy((void *)(bpage->vaddr + datacount1),
1055                             (void *)datavaddr, datacount2);
1056                         pmap_quick_remove_page(datavaddr);
1057
1058 next_r:
1059                         bpage = STAILQ_NEXT(bpage, links);
1060                 }
1061                 dmat->bounce_zone->total_bounced++;
1062         }
1063 }
1064
1065 static void
1066 init_bounce_pages(void *dummy __unused)
1067 {
1068
1069         total_bpages = 0;
1070         STAILQ_INIT(&bounce_zone_list);
1071         STAILQ_INIT(&bounce_map_waitinglist);
1072         STAILQ_INIT(&bounce_map_callbacklist);
1073         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1074 }
1075 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1076
1077 static struct sysctl_ctx_list *
1078 busdma_sysctl_tree(struct bounce_zone *bz)
1079 {
1080
1081         return (&bz->sysctl_tree);
1082 }
1083
1084 static struct sysctl_oid *
1085 busdma_sysctl_tree_top(struct bounce_zone *bz)
1086 {
1087
1088         return (bz->sysctl_tree_top);
1089 }
1090
1091 static int
1092 alloc_bounce_zone(bus_dma_tag_t dmat)
1093 {
1094         struct bounce_zone *bz;
1095
1096         /* Check to see if we already have a suitable zone */
1097         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1098                 if (dmat->common.alignment <= bz->alignment &&
1099                     dmat->common.lowaddr >= bz->lowaddr &&
1100                     dmat->common.domain == bz->domain) {
1101                         dmat->bounce_zone = bz;
1102                         return (0);
1103                 }
1104         }
1105
1106         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1107             M_NOWAIT | M_ZERO)) == NULL)
1108                 return (ENOMEM);
1109
1110         STAILQ_INIT(&bz->bounce_page_list);
1111         bz->free_bpages = 0;
1112         bz->reserved_bpages = 0;
1113         bz->active_bpages = 0;
1114         bz->lowaddr = dmat->common.lowaddr;
1115         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1116         bz->map_count = 0;
1117         bz->domain = dmat->common.domain;
1118         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1119         busdma_zonecount++;
1120         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1121         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1122         dmat->bounce_zone = bz;
1123
1124         sysctl_ctx_init(&bz->sysctl_tree);
1125         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1126             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1127             CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
1128         if (bz->sysctl_tree_top == NULL) {
1129                 sysctl_ctx_free(&bz->sysctl_tree);
1130                 return (0);     /* XXX error code? */
1131         }
1132
1133         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1134             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1135             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1136             "Total bounce pages");
1137         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1138             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1139             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1140             "Free bounce pages");
1141         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1142             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1143             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1144             "Reserved bounce pages");
1145         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1146             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1147             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1148             "Active bounce pages");
1149         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1150             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1151             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1152             "Total bounce requests");
1153         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1154             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1155             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1156             "Total bounce requests that were deferred");
1157         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1158             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1159             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1160         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1161             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1162             "alignment", CTLFLAG_RD, &bz->alignment, "");
1163         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1164             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1165             "domain", CTLFLAG_RD, &bz->domain, 0,
1166             "memory domain");
1167
1168         return (0);
1169 }
1170
1171 static int
1172 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1173 {
1174         struct bounce_zone *bz;
1175         int count;
1176
1177         bz = dmat->bounce_zone;
1178         count = 0;
1179         while (numpages > 0) {
1180                 struct bounce_page *bpage;
1181
1182                 bpage = malloc_domainset(sizeof(*bpage), M_DEVBUF,
1183                     DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
1184
1185                 if (bpage == NULL)
1186                         break;
1187                 bpage->vaddr = (vm_offset_t)contigmalloc_domainset(PAGE_SIZE,
1188                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT,
1189                     0ul, bz->lowaddr, PAGE_SIZE, 0);
1190                 if (bpage->vaddr == 0) {
1191                         free(bpage, M_DEVBUF);
1192                         break;
1193                 }
1194                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1195                 mtx_lock(&bounce_lock);
1196                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1197                 total_bpages++;
1198                 bz->total_bpages++;
1199                 bz->free_bpages++;
1200                 mtx_unlock(&bounce_lock);
1201                 count++;
1202                 numpages--;
1203         }
1204         return (count);
1205 }
1206
1207 static int
1208 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1209 {
1210         struct bounce_zone *bz;
1211         int pages;
1212
1213         mtx_assert(&bounce_lock, MA_OWNED);
1214         bz = dmat->bounce_zone;
1215         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1216         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1217                 return (map->pagesneeded - (map->pagesreserved + pages));
1218         bz->free_bpages -= pages;
1219         bz->reserved_bpages += pages;
1220         map->pagesreserved += pages;
1221         pages = map->pagesneeded - map->pagesreserved;
1222
1223         return (pages);
1224 }
1225
1226 static bus_addr_t
1227 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1228     vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size)
1229 {
1230         struct bounce_zone *bz;
1231         struct bounce_page *bpage;
1232
1233         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1234         KASSERT(map != NULL && map != &nobounce_dmamap,
1235             ("add_bounce_page: bad map %p", map));
1236
1237         bz = dmat->bounce_zone;
1238         if (map->pagesneeded == 0)
1239                 panic("add_bounce_page: map doesn't need any pages");
1240         map->pagesneeded--;
1241
1242         if (map->pagesreserved == 0)
1243                 panic("add_bounce_page: map doesn't need any pages");
1244         map->pagesreserved--;
1245
1246         mtx_lock(&bounce_lock);
1247         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1248         if (bpage == NULL)
1249                 panic("add_bounce_page: free page list is empty");
1250
1251         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1252         bz->reserved_bpages--;
1253         bz->active_bpages++;
1254         mtx_unlock(&bounce_lock);
1255
1256         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1257                 /* Page offset needs to be preserved. */
1258                 bpage->vaddr |= addr1 & PAGE_MASK;
1259                 bpage->busaddr |= addr1 & PAGE_MASK;
1260                 KASSERT(addr2 == 0,
1261         ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1262         }
1263         bpage->datavaddr = vaddr;
1264         bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1265         KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1266         bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1267         bpage->dataoffs = addr1 & PAGE_MASK;
1268         bpage->datacount = size;
1269         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1270         return (bpage->busaddr);
1271 }
1272
1273 static void
1274 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1275 {
1276         struct bus_dmamap *map;
1277         struct bounce_zone *bz;
1278
1279         bz = dmat->bounce_zone;
1280         bpage->datavaddr = 0;
1281         bpage->datacount = 0;
1282         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1283                 /*
1284                  * Reset the bounce page to start at offset 0.  Other uses
1285                  * of this bounce page may need to store a full page of
1286                  * data and/or assume it starts on a page boundary.
1287                  */
1288                 bpage->vaddr &= ~PAGE_MASK;
1289                 bpage->busaddr &= ~PAGE_MASK;
1290         }
1291
1292         mtx_lock(&bounce_lock);
1293         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1294         bz->free_bpages++;
1295         bz->active_bpages--;
1296         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1297                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1298                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1299                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1300                             map, links);
1301                         busdma_swi_pending = 1;
1302                         bz->total_deferred++;
1303                         swi_sched(vm_ih, 0);
1304                 }
1305         }
1306         mtx_unlock(&bounce_lock);
1307 }
1308
1309 void
1310 busdma_swi(void)
1311 {
1312         bus_dma_tag_t dmat;
1313         struct bus_dmamap *map;
1314
1315         mtx_lock(&bounce_lock);
1316         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1317                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1318                 mtx_unlock(&bounce_lock);
1319                 dmat = map->dmat;
1320                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1321                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1322                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1323                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1324                     BUS_DMA_UNLOCK);
1325                 mtx_lock(&bounce_lock);
1326         }
1327         mtx_unlock(&bounce_lock);
1328 }
1329
1330 struct bus_dma_impl bus_dma_bounce_impl = {
1331         .tag_create = bounce_bus_dma_tag_create,
1332         .tag_destroy = bounce_bus_dma_tag_destroy,
1333         .tag_set_domain = bounce_bus_dma_tag_set_domain,
1334         .id_mapped = bounce_bus_dma_id_mapped,
1335         .map_create = bounce_bus_dmamap_create,
1336         .map_destroy = bounce_bus_dmamap_destroy,
1337         .mem_alloc = bounce_bus_dmamem_alloc,
1338         .mem_free = bounce_bus_dmamem_free,
1339         .load_phys = bounce_bus_dmamap_load_phys,
1340         .load_buffer = bounce_bus_dmamap_load_buffer,
1341         .load_ma = bounce_bus_dmamap_load_ma,
1342         .map_waitok = bounce_bus_dmamap_waitok,
1343         .map_complete = bounce_bus_dmamap_complete,
1344         .map_unload = bounce_bus_dmamap_unload,
1345         .map_sync = bounce_bus_dmamap_sync,
1346 };