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_domain(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_domain(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         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
 411
 412         if (flags & BUS_DMA_NOWAIT)
 413                 mflags = M_NOWAIT;
 414         else
 415                 mflags = M_WAITOK;
 416
 417         /* If we succeed, no mapping/bouncing will be required */
 418         *mapp = NULL;
 419
 420         if (dmat->segments == NULL) {
 421                 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
 422                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 423                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), mflags);
 424                 if (dmat->segments == NULL) {
 425                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 426                             __func__, dmat, dmat->common.flags, ENOMEM);
 427                         return (ENOMEM);
 428                 }
 429         }
 430         if (flags & BUS_DMA_ZERO)
 431                 mflags |= M_ZERO;
 432         if (flags & BUS_DMA_NOCACHE)
 433                 attr = VM_MEMATTR_UNCACHEABLE;
 434         else
 435                 attr = VM_MEMATTR_DEFAULT;
 436
 437         /*
 438          * Allocate the buffer from the malloc(9) allocator if...
 439          *  - It's small enough to fit into a single power of two sized bucket.
 440          *  - The alignment is less than or equal to the maximum size
 441          *  - The low address requirement is fulfilled.
 442          * else allocate non-contiguous pages if...
 443          *  - The page count that could get allocated doesn't exceed
 444          *    nsegments also when the maximum segment size is less
 445          *    than PAGE_SIZE.
 446          *  - The alignment constraint isn't larger than a page boundary.
 447          *  - There are no boundary-crossing constraints.
 448          * else allocate a block of contiguous pages because one or more of the
 449          * constraints is something that only the contig allocator can fulfill.
 450          *
 451          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 452          * below is just a quick hack. The exact alignment guarantees
 453          * of malloc(9) need to be nailed down, and the code below
 454          * should be rewritten to take that into account.
 455          *
 456          * In the meantime warn the user if malloc gets it wrong.
 457          */
 458         if (dmat->common.maxsize <= PAGE_SIZE &&
 459             dmat->common.alignment <= dmat->common.maxsize &&
 460             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 461             attr == VM_MEMATTR_DEFAULT) {
 462                 *vaddr = malloc_domainset(dmat->common.maxsize, M_DEVBUF,
 463                     DOMAINSET_PREF(dmat->common.domain), mflags);
 464         } else if (dmat->common.nsegments >=
 465             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz,
 466             PAGE_SIZE)) &&
 467             dmat->common.alignment <= PAGE_SIZE &&
 468             (dmat->common.boundary % PAGE_SIZE) == 0) {
 469                 /* Page-based multi-segment allocations allowed */
 470                 *vaddr = (void *)kmem_alloc_attr_domainset(
 471                     DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
 472                     mflags, 0ul, dmat->common.lowaddr, attr);
 473                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 474         } else {
 475                 *vaddr = (void *)kmem_alloc_contig_domainset(
 476                     DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
 477                     mflags, 0ul, dmat->common.lowaddr,
 478                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 479                     dmat->common.boundary, attr);
 480                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 481         }
 482         if (*vaddr == NULL) {
 483                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 484                     __func__, dmat, dmat->common.flags, ENOMEM);
 485                 return (ENOMEM);
 486         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 487                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 488         }
 489         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 490             __func__, dmat, dmat->common.flags, 0);
 491         return (0);
 492 }
 493
 494 /*
 495  * Free a piece of memory and it's allociated dmamap, that was allocated
 496  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 497  */
 498 static void
 499 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 500 {
 501         /*
 502          * dmamem does not need to be bounced, so the map should be
 503          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 504          * was used and set if kmem_alloc_contig() was used.
 505          */
 506         if (map != NULL)
 507                 panic("bus_dmamem_free: Invalid map freed\n");
 508         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 509                 free_domain(vaddr, M_DEVBUF);
 510         else
 511                 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 512         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 513             dmat->bounce_flags);
 514 }
 515
 516 static bool
 517 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
 518     int *pagesneeded)
 519 {
 520         vm_paddr_t curaddr;
 521         bus_size_t sgsize;
 522         int count;
 523
 524         /*
 525          * Count the number of bounce pages needed in order to
 526          * complete this transfer
 527          */
 528         count = 0;
 529         curaddr = buf;
 530         while (buflen != 0) {
 531                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 532                 if (bus_dma_run_filter(&dmat->common, curaddr)) {
 533                         sgsize = MIN(sgsize,
 534                             PAGE_SIZE - (curaddr & PAGE_MASK));
 535                         if (pagesneeded == NULL)
 536                                 return (true);
 537                         count++;
 538                 }
 539                 curaddr += sgsize;
 540                 buflen -= sgsize;
 541         }
 542
 543         if (pagesneeded != NULL)
 544                 *pagesneeded = count;
 545         return (count != 0);
 546 }
 547
 548 static void
 549 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 550     bus_size_t buflen, int flags)
 551 {
 552
 553         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 554                 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
 555                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 556         }
 557 }
 558
 559 static void
 560 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 561     void *buf, bus_size_t buflen, int flags)
 562 {
 563         vm_offset_t vaddr;
 564         vm_offset_t vendaddr;
 565         vm_paddr_t paddr;
 566         bus_size_t sg_len;
 567
 568         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 569                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 570                     "alignment= %d", dmat->common.lowaddr,
 571                     ptoa((vm_paddr_t)Maxmem),
 572                     dmat->common.boundary, dmat->common.alignment);
 573                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 574                     map, &nobounce_dmamap, map->pagesneeded);
 575                 /*
 576                  * Count the number of bounce pages
 577                  * needed in order to complete this transfer
 578                  */
 579                 vaddr = (vm_offset_t)buf;
 580                 vendaddr = (vm_offset_t)buf + buflen;
 581
 582                 while (vaddr < vendaddr) {
 583                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 584                         if (pmap == kernel_pmap)
 585                                 paddr = pmap_kextract(vaddr);
 586                         else
 587                                 paddr = pmap_extract(pmap, vaddr);
 588                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 589                                 sg_len = roundup2(sg_len,
 590                                     dmat->common.alignment);
 591                                 map->pagesneeded++;
 592                         }
 593                         vaddr += sg_len;
 594                 }
 595                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 596         }
 597 }
 598
 599 static void
 600 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 601     int ma_offs, bus_size_t buflen, int flags)
 602 {
 603         bus_size_t sg_len, max_sgsize;
 604         int page_index;
 605         vm_paddr_t paddr;
 606
 607         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 608                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 609                     "alignment= %d", dmat->common.lowaddr,
 610                     ptoa((vm_paddr_t)Maxmem),
 611                     dmat->common.boundary, dmat->common.alignment);
 612                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 613                     map, &nobounce_dmamap, map->pagesneeded);
 614
 615                 /*
 616                  * Count the number of bounce pages
 617                  * needed in order to complete this transfer
 618                  */
 619                 page_index = 0;
 620                 while (buflen > 0) {
 621                         paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 622                         sg_len = PAGE_SIZE - ma_offs;
 623                         max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 624                         sg_len = MIN(sg_len, max_sgsize);
 625                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 626                                 sg_len = roundup2(sg_len,
 627                                     dmat->common.alignment);
 628                                 sg_len = MIN(sg_len, max_sgsize);
 629                                 KASSERT((sg_len & (dmat->common.alignment - 1))
 630                                     == 0, ("Segment size is not aligned"));
 631                                 map->pagesneeded++;
 632                         }
 633                         if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
 634                                 page_index++;
 635                         ma_offs = (ma_offs + sg_len) & PAGE_MASK;
 636                         KASSERT(buflen >= sg_len,
 637                             ("Segment length overruns original buffer"));
 638                         buflen -= sg_len;
 639                 }
 640                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 641         }
 642 }
 643
 644 static int
 645 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 646 {
 647
 648         /* Reserve Necessary Bounce Pages */
 649         mtx_lock(&bounce_lock);
 650         if (flags & BUS_DMA_NOWAIT) {
 651                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 652                         mtx_unlock(&bounce_lock);
 653                         return (ENOMEM);
 654                 }
 655         } else {
 656                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 657                         /* Queue us for resources */
 658                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 659                         mtx_unlock(&bounce_lock);
 660                         return (EINPROGRESS);
 661                 }
 662         }
 663         mtx_unlock(&bounce_lock);
 664
 665         return (0);
 666 }
 667
 668 /*
 669  * Add a single contiguous physical range to the segment list.
 670  */
 671 static bus_size_t
 672 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t curaddr,
 673     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 674 {
 675         bus_addr_t baddr, bmask;
 676         int seg;
 677
 678         KASSERT(curaddr <= BUS_SPACE_MAXADDR,
 679             ("ds_addr %#jx > BUS_SPACE_MAXADDR %#jx; dmat %p fl %#x low %#jx "
 680             "hi %#jx",
 681             (uintmax_t)curaddr, (uintmax_t)BUS_SPACE_MAXADDR,
 682             dmat, dmat->bounce_flags, (uintmax_t)dmat->common.lowaddr,
 683             (uintmax_t)dmat->common.highaddr));
 684
 685         /*
 686          * Make sure we don't cross any boundaries.
 687          */
 688         bmask = ~(dmat->common.boundary - 1);
 689         if (dmat->common.boundary > 0) {
 690                 baddr = (curaddr + dmat->common.boundary) & bmask;
 691                 if (sgsize > (baddr - curaddr))
 692                         sgsize = (baddr - curaddr);
 693         }
 694
 695         /*
 696          * Insert chunk into a segment, coalescing with
 697          * previous segment if possible.
 698          */
 699         seg = *segp;
 700         if (seg == -1) {
 701                 seg = 0;
 702                 segs[seg].ds_addr = curaddr;
 703                 segs[seg].ds_len = sgsize;
 704         } else {
 705                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 706                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 707                     (dmat->common.boundary == 0 ||
 708                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 709                         segs[seg].ds_len += sgsize;
 710                 else {
 711                         if (++seg >= dmat->common.nsegments)
 712                                 return (0);
 713                         segs[seg].ds_addr = curaddr;
 714                         segs[seg].ds_len = sgsize;
 715                 }
 716         }
 717         *segp = seg;
 718         return (sgsize);
 719 }
 720
 721 /*
 722  * Utility function to load a physical buffer.  segp contains
 723  * the starting segment on entrace, and the ending segment on exit.
 724  */
 725 static int
 726 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 727     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 728     int *segp)
 729 {
 730         bus_size_t sgsize;
 731         vm_paddr_t curaddr;
 732         int error;
 733
 734         if (map == NULL)
 735                 map = &nobounce_dmamap;
 736
 737         if (segs == NULL)
 738                 segs = dmat->segments;
 739
 740         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 741                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 742                 if (map->pagesneeded != 0) {
 743                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 744                         if (error)
 745                                 return (error);
 746                 }
 747         }
 748
 749         while (buflen > 0) {
 750                 curaddr = buf;
 751                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 752                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 753                     map->pagesneeded != 0 &&
 754                     bus_dma_run_filter(&dmat->common, curaddr)) {
 755                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 756                         curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
 757                             sgsize);
 758                 }
 759                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 760                     segp);
 761                 if (sgsize == 0)
 762                         break;
 763                 buf += sgsize;
 764                 buflen -= sgsize;
 765         }
 766
 767         /*
 768          * Did we fit?
 769          */
 770         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 771 }
 772
 773 /*
 774  * Utility function to load a linear buffer.  segp contains
 775  * the starting segment on entrace, and the ending segment on exit.
 776  */
 777 static int
 778 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 779     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 780     int *segp)
 781 {
 782         bus_size_t sgsize, max_sgsize;
 783         vm_paddr_t curaddr;
 784         vm_offset_t kvaddr, vaddr;
 785         int error;
 786
 787         if (map == NULL)
 788                 map = &nobounce_dmamap;
 789
 790         if (segs == NULL)
 791                 segs = dmat->segments;
 792
 793         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 794                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 795                 if (map->pagesneeded != 0) {
 796                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 797                         if (error)
 798                                 return (error);
 799                 }
 800         }
 801
 802         vaddr = (vm_offset_t)buf;
 803         while (buflen > 0) {
 804                 /*
 805                  * Get the physical address for this segment.
 806                  */
 807                 if (pmap == kernel_pmap) {
 808                         curaddr = pmap_kextract(vaddr);
 809                         kvaddr = vaddr;
 810                 } else {
 811                         curaddr = pmap_extract(pmap, vaddr);
 812                         kvaddr = 0;
 813                 }
 814
 815                 /*
 816                  * Compute the segment size, and adjust counts.
 817                  */
 818                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 819                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 820                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 821                     map->pagesneeded != 0 &&
 822                     bus_dma_run_filter(&dmat->common, curaddr)) {
 823                         sgsize = roundup2(sgsize, dmat->common.alignment);
 824                         sgsize = MIN(sgsize, max_sgsize);
 825                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 826                             sgsize);
 827                 } else {
 828                         sgsize = MIN(sgsize, max_sgsize);
 829                 }
 830                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 831                     segp);
 832                 if (sgsize == 0)
 833                         break;
 834                 vaddr += sgsize;
 835                 buflen -= sgsize;
 836         }
 837
 838         /*
 839          * Did we fit?
 840          */
 841         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 842 }
 843
 844 static int
 845 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 846     struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
 847     bus_dma_segment_t *segs, int *segp)
 848 {
 849         vm_paddr_t paddr, next_paddr;
 850         int error, page_index;
 851         bus_size_t sgsize, max_sgsize;
 852
 853         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 854                 /*
 855                  * If we have to keep the offset of each page this function
 856                  * is not suitable, switch back to bus_dmamap_load_ma_triv
 857                  * which is going to do the right thing in this case.
 858                  */
 859                 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
 860                     flags, segs, segp);
 861                 return (error);
 862         }
 863
 864         if (map == NULL)
 865                 map = &nobounce_dmamap;
 866
 867         if (segs == NULL)
 868                 segs = dmat->segments;
 869
 870         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 871                 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
 872                 if (map->pagesneeded != 0) {
 873                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 874                         if (error)
 875                                 return (error);
 876                 }
 877         }
 878
 879         page_index = 0;
 880         while (buflen > 0) {
 881                 /*
 882                  * Compute the segment size, and adjust counts.
 883                  */
 884                 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 885                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 886                 sgsize = PAGE_SIZE - ma_offs;
 887                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 888                     map->pagesneeded != 0 &&
 889                     bus_dma_run_filter(&dmat->common, paddr)) {
 890                         sgsize = roundup2(sgsize, dmat->common.alignment);
 891                         sgsize = MIN(sgsize, max_sgsize);
 892                         KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
 893                             ("Segment size is not aligned"));
 894                         /*
 895                          * Check if two pages of the user provided buffer
 896                          * are used.
 897                          */
 898                         if ((ma_offs + sgsize) > PAGE_SIZE)
 899                                 next_paddr =
 900                                     VM_PAGE_TO_PHYS(ma[page_index + 1]);
 901                         else
 902                                 next_paddr = 0;
 903                         paddr = add_bounce_page(dmat, map, 0, paddr,
 904                             next_paddr, sgsize);
 905                 } else {
 906                         sgsize = MIN(sgsize, max_sgsize);
 907                 }
 908                 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
 909                     segp);
 910                 if (sgsize == 0)
 911                         break;
 912                 KASSERT(buflen >= sgsize,
 913                     ("Segment length overruns original buffer"));
 914                 buflen -= sgsize;
 915                 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
 916                         page_index++;
 917                 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
 918         }
 919
 920         /*
 921          * Did we fit?
 922          */
 923         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 924 }
 925
 926 static void
 927 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 928     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 929 {
 930
 931         if (map == NULL)
 932                 return;
 933         map->mem = *mem;
 934         map->dmat = dmat;
 935         map->callback = callback;
 936         map->callback_arg = callback_arg;
 937 }
 938
 939 static bus_dma_segment_t *
 940 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 941     bus_dma_segment_t *segs, int nsegs, int error)
 942 {
 943
 944         if (segs == NULL)
 945                 segs = dmat->segments;
 946         return (segs);
 947 }
 948
 949 /*
 950  * Release the mapping held by map.
 951  */
 952 static void
 953 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 954 {
 955         struct bounce_page *bpage;
 956
 957         if (map == NULL)
 958                 return;
 959
 960         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 961                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 962                 free_bounce_page(dmat, bpage);
 963         }
 964 }
 965
 966 static void
 967 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 968     bus_dmasync_op_t op)
 969 {
 970         struct bounce_page *bpage;
 971         vm_offset_t datavaddr, tempvaddr;
 972         bus_size_t datacount1, datacount2;
 973
 974         if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 975                 return;
 976
 977         /*
 978          * Handle data bouncing.  We might also want to add support for
 979          * invalidating the caches on broken hardware.
 980          */
 981         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 982             "performing bounce", __func__, dmat, dmat->common.flags, op);
 983
 984         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 985                 while (bpage != NULL) {
 986                         tempvaddr = 0;
 987                         datavaddr = bpage->datavaddr;
 988                         datacount1 = bpage->datacount;
 989                         if (datavaddr == 0) {
 990                                 tempvaddr =
 991                                     pmap_quick_enter_page(bpage->datapage[0]);
 992                                 datavaddr = tempvaddr | bpage->dataoffs;
 993                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 994                                     datacount1);
 995                         }
 996
 997                         bcopy((void *)datavaddr,
 998                             (void *)bpage->vaddr, datacount1);
 999
1000                         if (tempvaddr != 0)
1001                                 pmap_quick_remove_page(tempvaddr);
1002
1003                         if (bpage->datapage[1] == 0) {
1004                                 KASSERT(datacount1 == bpage->datacount,
1005                 ("Mismatch between data size and provided memory space"));
1006                                 goto next_w;
1007                         }
1008
1009                         /*
1010                          * We are dealing with an unmapped buffer that expands
1011                          * over two pages.
1012                          */
1013                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1014                         datacount2 = bpage->datacount - datacount1;
1015                         bcopy((void *)datavaddr,
1016                             (void *)(bpage->vaddr + datacount1), datacount2);
1017                         pmap_quick_remove_page(datavaddr);
1018
1019 next_w:
1020                         bpage = STAILQ_NEXT(bpage, links);
1021                 }
1022                 dmat->bounce_zone->total_bounced++;
1023         }
1024
1025         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1026                 while (bpage != NULL) {
1027                         tempvaddr = 0;
1028                         datavaddr = bpage->datavaddr;
1029                         datacount1 = bpage->datacount;
1030                         if (datavaddr == 0) {
1031                                 tempvaddr =
1032                                     pmap_quick_enter_page(bpage->datapage[0]);
1033                                 datavaddr = tempvaddr | bpage->dataoffs;
1034                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
1035                                     datacount1);
1036                         }
1037
1038                         bcopy((void *)bpage->vaddr, (void *)datavaddr,
1039                             datacount1);
1040
1041                         if (tempvaddr != 0)
1042                                 pmap_quick_remove_page(tempvaddr);
1043
1044                         if (bpage->datapage[1] == 0) {
1045                                 KASSERT(datacount1 == bpage->datacount,
1046                 ("Mismatch between data size and provided memory space"));
1047                                 goto next_r;
1048                         }
1049
1050                         /*
1051                          * We are dealing with an unmapped buffer that expands
1052                          * over two pages.
1053                          */
1054                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1055                         datacount2 = bpage->datacount - datacount1;
1056                         bcopy((void *)(bpage->vaddr + datacount1),
1057                             (void *)datavaddr, datacount2);
1058                         pmap_quick_remove_page(datavaddr);
1059
1060 next_r:
1061                         bpage = STAILQ_NEXT(bpage, links);
1062                 }
1063                 dmat->bounce_zone->total_bounced++;
1064         }
1065 }
1066
1067 static void
1068 init_bounce_pages(void *dummy __unused)
1069 {
1070
1071         total_bpages = 0;
1072         STAILQ_INIT(&bounce_zone_list);
1073         STAILQ_INIT(&bounce_map_waitinglist);
1074         STAILQ_INIT(&bounce_map_callbacklist);
1075         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1076 }
1077 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1078
1079 static struct sysctl_ctx_list *
1080 busdma_sysctl_tree(struct bounce_zone *bz)
1081 {
1082
1083         return (&bz->sysctl_tree);
1084 }
1085
1086 static struct sysctl_oid *
1087 busdma_sysctl_tree_top(struct bounce_zone *bz)
1088 {
1089
1090         return (bz->sysctl_tree_top);
1091 }
1092
1093 static int
1094 alloc_bounce_zone(bus_dma_tag_t dmat)
1095 {
1096         struct bounce_zone *bz;
1097
1098         /* Check to see if we already have a suitable zone */
1099         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1100                 if (dmat->common.alignment <= bz->alignment &&
1101                     dmat->common.lowaddr >= bz->lowaddr &&
1102                     dmat->common.domain == bz->domain) {
1103                         dmat->bounce_zone = bz;
1104                         return (0);
1105                 }
1106         }
1107
1108         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1109             M_NOWAIT | M_ZERO)) == NULL)
1110                 return (ENOMEM);
1111
1112         STAILQ_INIT(&bz->bounce_page_list);
1113         bz->free_bpages = 0;
1114         bz->reserved_bpages = 0;
1115         bz->active_bpages = 0;
1116         bz->lowaddr = dmat->common.lowaddr;
1117         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1118         bz->map_count = 0;
1119         bz->domain = dmat->common.domain;
1120         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1121         busdma_zonecount++;
1122         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1123         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1124         dmat->bounce_zone = bz;
1125
1126         sysctl_ctx_init(&bz->sysctl_tree);
1127         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1128             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1129             CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
1130         if (bz->sysctl_tree_top == NULL) {
1131                 sysctl_ctx_free(&bz->sysctl_tree);
1132                 return (0);     /* XXX error code? */
1133         }
1134
1135         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1136             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1137             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1138             "Total bounce pages");
1139         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1140             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1141             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1142             "Free bounce pages");
1143         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1144             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1145             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1146             "Reserved bounce pages");
1147         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1148             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1149             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1150             "Active bounce pages");
1151         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1152             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1153             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1154             "Total bounce requests");
1155         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1156             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1157             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1158             "Total bounce requests that were deferred");
1159         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1160             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1161             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1162         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1163             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1164             "alignment", CTLFLAG_RD, &bz->alignment, "");
1165         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1166             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1167             "domain", CTLFLAG_RD, &bz->domain, 0,
1168             "memory domain");
1169
1170         return (0);
1171 }
1172
1173 static int
1174 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1175 {
1176         struct bounce_zone *bz;
1177         int count;
1178
1179         bz = dmat->bounce_zone;
1180         count = 0;
1181         while (numpages > 0) {
1182                 struct bounce_page *bpage;
1183
1184                 bpage = malloc_domainset(sizeof(*bpage), M_DEVBUF,
1185                     DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
1186
1187                 if (bpage == NULL)
1188                         break;
1189                 bpage->vaddr = (vm_offset_t)contigmalloc_domainset(PAGE_SIZE,
1190                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT,
1191                     0ul, bz->lowaddr, PAGE_SIZE, 0);
1192                 if (bpage->vaddr == 0) {
1193                         free_domain(bpage, M_DEVBUF);
1194                         break;
1195                 }
1196                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1197                 mtx_lock(&bounce_lock);
1198                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1199                 total_bpages++;
1200                 bz->total_bpages++;
1201                 bz->free_bpages++;
1202                 mtx_unlock(&bounce_lock);
1203                 count++;
1204                 numpages--;
1205         }
1206         return (count);
1207 }
1208
1209 static int
1210 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1211 {
1212         struct bounce_zone *bz;
1213         int pages;
1214
1215         mtx_assert(&bounce_lock, MA_OWNED);
1216         bz = dmat->bounce_zone;
1217         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1218         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1219                 return (map->pagesneeded - (map->pagesreserved + pages));
1220         bz->free_bpages -= pages;
1221         bz->reserved_bpages += pages;
1222         map->pagesreserved += pages;
1223         pages = map->pagesneeded - map->pagesreserved;
1224
1225         return (pages);
1226 }
1227
1228 static bus_addr_t
1229 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1230     vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size)
1231 {
1232         struct bounce_zone *bz;
1233         struct bounce_page *bpage;
1234
1235         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1236         KASSERT(map != NULL && map != &nobounce_dmamap,
1237             ("add_bounce_page: bad map %p", map));
1238
1239         bz = dmat->bounce_zone;
1240         if (map->pagesneeded == 0)
1241                 panic("add_bounce_page: map doesn't need any pages");
1242         map->pagesneeded--;
1243
1244         if (map->pagesreserved == 0)
1245                 panic("add_bounce_page: map doesn't need any pages");
1246         map->pagesreserved--;
1247
1248         mtx_lock(&bounce_lock);
1249         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1250         if (bpage == NULL)
1251                 panic("add_bounce_page: free page list is empty");
1252
1253         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1254         bz->reserved_bpages--;
1255         bz->active_bpages++;
1256         mtx_unlock(&bounce_lock);
1257
1258         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1259                 /* Page offset needs to be preserved. */
1260                 bpage->vaddr |= addr1 & PAGE_MASK;
1261                 bpage->busaddr |= addr1 & PAGE_MASK;
1262                 KASSERT(addr2 == 0,
1263         ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1264         }
1265         bpage->datavaddr = vaddr;
1266         bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1267         KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1268         bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1269         bpage->dataoffs = addr1 & PAGE_MASK;
1270         bpage->datacount = size;
1271         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1272         return (bpage->busaddr);
1273 }
1274
1275 static void
1276 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1277 {
1278         struct bus_dmamap *map;
1279         struct bounce_zone *bz;
1280
1281         bz = dmat->bounce_zone;
1282         bpage->datavaddr = 0;
1283         bpage->datacount = 0;
1284         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1285                 /*
1286                  * Reset the bounce page to start at offset 0.  Other uses
1287                  * of this bounce page may need to store a full page of
1288                  * data and/or assume it starts on a page boundary.
1289                  */
1290                 bpage->vaddr &= ~PAGE_MASK;
1291                 bpage->busaddr &= ~PAGE_MASK;
1292         }
1293
1294         mtx_lock(&bounce_lock);
1295         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1296         bz->free_bpages++;
1297         bz->active_bpages--;
1298         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1299                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1300                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1301                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1302                             map, links);
1303                         busdma_swi_pending = 1;
1304                         bz->total_deferred++;
1305                         swi_sched(vm_ih, 0);
1306                 }
1307         }
1308         mtx_unlock(&bounce_lock);
1309 }
1310
1311 void
1312 busdma_swi(void)
1313 {
1314         bus_dma_tag_t dmat;
1315         struct bus_dmamap *map;
1316
1317         mtx_lock(&bounce_lock);
1318         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1319                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1320                 mtx_unlock(&bounce_lock);
1321                 dmat = map->dmat;
1322                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1323                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1324                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1325                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1326                     BUS_DMA_UNLOCK);
1327                 mtx_lock(&bounce_lock);
1328         }
1329         mtx_unlock(&bounce_lock);
1330 }
1331
1332 struct bus_dma_impl bus_dma_bounce_impl = {
1333         .tag_create = bounce_bus_dma_tag_create,
1334         .tag_destroy = bounce_bus_dma_tag_destroy,
1335         .tag_set_domain = bounce_bus_dma_tag_set_domain,
1336         .id_mapped = bounce_bus_dma_id_mapped,
1337         .map_create = bounce_bus_dmamap_create,
1338         .map_destroy = bounce_bus_dmamap_destroy,
1339         .mem_alloc = bounce_bus_dmamem_alloc,
1340         .mem_free = bounce_bus_dmamem_free,
1341         .load_phys = bounce_bus_dmamap_load_phys,
1342         .load_buffer = bounce_bus_dmamap_load_buffer,
1343         .load_ma = bounce_bus_dmamap_load_ma,
1344         .map_waitok = bounce_bus_dmamap_waitok,
1345         .map_complete = bounce_bus_dmamap_complete,
1346         .map_unload = bounce_bus_dmamap_unload,
1347         .map_sync = bounce_bus_dmamap_sync,
1348 };