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