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 bool _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf,
 145     bus_size_t buflen, int *pagesneeded);
 146 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 147     pmap_t pmap, void *buf, bus_size_t buflen, int flags);
 148 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 149     vm_paddr_t buf, bus_size_t buflen, int flags);
 150 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 151     int flags);
 152
 153 static int
 154 bounce_bus_dma_zone_setup(bus_dma_tag_t dmat)
 155 {
 156         struct bounce_zone *bz;
 157         int error;
 158
 159         /* Must bounce */
 160         if ((error = alloc_bounce_zone(dmat)) != 0)
 161                 return (error);
 162         bz = dmat->bounce_zone;
 163
 164         if (ptoa(bz->total_bpages) < dmat->common.maxsize) {
 165                 int pages;
 166
 167                 pages = atop(dmat->common.maxsize) - bz->total_bpages;
 168
 169                 /* Add pages to our bounce pool */
 170                 if (alloc_bounce_pages(dmat, pages) < pages)
 171                         return (ENOMEM);
 172         }
 173         /* Performed initial allocation */
 174         dmat->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 175
 176         return (0);
 177 }
 178
 179 /*
 180  * Allocate a device specific dma_tag.
 181  */
 182 static int
 183 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 184     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 185     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 186     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 187     void *lockfuncarg, bus_dma_tag_t *dmat)
 188 {
 189         bus_dma_tag_t newtag;
 190         int error;
 191
 192         *dmat = NULL;
 193         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 194             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 195             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 196             sizeof (struct bus_dma_tag), (void **)&newtag);
 197         if (error != 0)
 198                 return (error);
 199
 200         newtag->common.impl = &bus_dma_bounce_impl;
 201         newtag->map_count = 0;
 202         newtag->segments = NULL;
 203
 204         if (parent != NULL && (newtag->common.filter != NULL ||
 205             (parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0))
 206                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 207
 208         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 209             newtag->common.alignment > 1)
 210                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 211
 212         if ((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 213             (flags & BUS_DMA_ALLOCNOW) != 0)
 214                 error = bounce_bus_dma_zone_setup(newtag);
 215         else
 216                 error = 0;
 217
 218         if (error != 0)
 219                 free(newtag, M_DEVBUF);
 220         else
 221                 *dmat = newtag;
 222         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 223             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 224             error);
 225         return (error);
 226 }
 227
 228 static bool
 229 bounce_bus_dma_id_mapped(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen)
 230 {
 231
 232         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0)
 233                 return (true);
 234         return (!_bus_dmamap_pagesneeded(dmat, buf, buflen, NULL));
 235 }
 236
 237 /*
 238  * Update the domain for the tag.  We may need to reallocate the zone and
 239  * bounce pages.
 240  */
 241 static int
 242 bounce_bus_dma_tag_set_domain(bus_dma_tag_t dmat)
 243 {
 244
 245         KASSERT(dmat->map_count == 0,
 246             ("bounce_bus_dma_tag_set_domain:  Domain set after use.\n"));
 247         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0 ||
 248             dmat->bounce_zone == NULL)
 249                 return (0);
 250         dmat->bounce_flags &= ~BUS_DMA_MIN_ALLOC_COMP;
 251         return (bounce_bus_dma_zone_setup(dmat));
 252 }
 253
 254 static int
 255 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 256 {
 257         bus_dma_tag_t dmat_copy, parent;
 258         int error;
 259
 260         error = 0;
 261         dmat_copy = dmat;
 262
 263         if (dmat != NULL) {
 264                 if (dmat->map_count != 0) {
 265                         error = EBUSY;
 266                         goto out;
 267                 }
 268                 while (dmat != NULL) {
 269                         parent = (bus_dma_tag_t)dmat->common.parent;
 270                         atomic_subtract_int(&dmat->common.ref_count, 1);
 271                         if (dmat->common.ref_count == 0) {
 272                                 if (dmat->segments != NULL)
 273                                         free_domain(dmat->segments, M_DEVBUF);
 274                                 free(dmat, M_DEVBUF);
 275                                 /*
 276                                  * Last reference count, so
 277                                  * release our reference
 278                                  * count on our parent.
 279                                  */
 280                                 dmat = parent;
 281                         } else
 282                                 dmat = NULL;
 283                 }
 284         }
 285 out:
 286         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 287         return (error);
 288 }
 289
 290 /*
 291  * Allocate a handle for mapping from kva/uva/physical
 292  * address space into bus device space.
 293  */
 294 static int
 295 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 296 {
 297         struct bounce_zone *bz;
 298         int error, maxpages, pages;
 299
 300         error = 0;
 301
 302         if (dmat->segments == NULL) {
 303                 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
 304                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 305                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT);
 306                 if (dmat->segments == NULL) {
 307                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 308                             __func__, dmat, ENOMEM);
 309                         return (ENOMEM);
 310                 }
 311         }
 312
 313         /*
 314          * Bouncing might be required if the driver asks for an active
 315          * exclusion region, a data alignment that is stricter than 1, and/or
 316          * an active address boundary.
 317          */
 318         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 319                 /* Must bounce */
 320                 if (dmat->bounce_zone == NULL) {
 321                         if ((error = alloc_bounce_zone(dmat)) != 0)
 322                                 return (error);
 323                 }
 324                 bz = dmat->bounce_zone;
 325
 326                 *mapp = (bus_dmamap_t)malloc_domainset(sizeof(**mapp), M_DEVBUF,
 327                     DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
 328                 if (*mapp == NULL) {
 329                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 330                             __func__, dmat, ENOMEM);
 331                         return (ENOMEM);
 332                 }
 333
 334                 /* Initialize the new map */
 335                 STAILQ_INIT(&((*mapp)->bpages));
 336
 337                 /*
 338                  * Attempt to add pages to our pool on a per-instance
 339                  * basis up to a sane limit.
 340                  */
 341                 if (dmat->common.alignment > 1)
 342                         maxpages = MAX_BPAGES;
 343                 else
 344                         maxpages = MIN(MAX_BPAGES, Maxmem -
 345                             atop(dmat->common.lowaddr));
 346                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 347                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 348                         pages = MAX(atop(dmat->common.maxsize), 1);
 349                         pages = MIN(maxpages - bz->total_bpages, pages);
 350                         pages = MAX(pages, 1);
 351                         if (alloc_bounce_pages(dmat, pages) < pages)
 352                                 error = ENOMEM;
 353                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 354                             == 0) {
 355                                 if (error == 0) {
 356                                         dmat->bounce_flags |=
 357                                             BUS_DMA_MIN_ALLOC_COMP;
 358                                 }
 359                         } else
 360                                 error = 0;
 361                 }
 362                 bz->map_count++;
 363         } else {
 364                 *mapp = NULL;
 365         }
 366         if (error == 0)
 367                 dmat->map_count++;
 368         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 369             __func__, dmat, dmat->common.flags, error);
 370         return (error);
 371 }
 372
 373 /*
 374  * Destroy a handle for mapping from kva/uva/physical
 375  * address space into bus device space.
 376  */
 377 static int
 378 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 379 {
 380
 381         if (map != NULL && map != &nobounce_dmamap) {
 382                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 383                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 384                             __func__, dmat, EBUSY);
 385                         return (EBUSY);
 386                 }
 387                 if (dmat->bounce_zone)
 388                         dmat->bounce_zone->map_count--;
 389                 free_domain(map, M_DEVBUF);
 390         }
 391         dmat->map_count--;
 392         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 393         return (0);
 394 }
 395
 396
 397 /*
 398  * Allocate a piece of memory that can be efficiently mapped into
 399  * bus device space based on the constraints lited in the dma tag.
 400  * A dmamap to for use with dmamap_load is also allocated.
 401  */
 402 static int
 403 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 404     bus_dmamap_t *mapp)
 405 {
 406         vm_memattr_t attr;
 407         int mflags;
 408
 409         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
 410
 411         if (flags & BUS_DMA_NOWAIT)
 412                 mflags = M_NOWAIT;
 413         else
 414                 mflags = M_WAITOK;
 415
 416         /* If we succeed, no mapping/bouncing will be required */
 417         *mapp = NULL;
 418
 419         if (dmat->segments == NULL) {
 420                 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
 421                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 422                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), mflags);
 423                 if (dmat->segments == NULL) {
 424                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 425                             __func__, dmat, dmat->common.flags, ENOMEM);
 426                         return (ENOMEM);
 427                 }
 428         }
 429         if (flags & BUS_DMA_ZERO)
 430                 mflags |= M_ZERO;
 431         if (flags & BUS_DMA_NOCACHE)
 432                 attr = VM_MEMATTR_UNCACHEABLE;
 433         else
 434                 attr = VM_MEMATTR_DEFAULT;
 435
 436         /*
 437          * Allocate the buffer from the malloc(9) allocator if...
 438          *  - It's small enough to fit into a single power of two sized bucket.
 439          *  - The alignment is less than or equal to the maximum size
 440          *  - The low address requirement is fulfilled.
 441          * else allocate non-contiguous pages if...
 442          *  - The page count that could get allocated doesn't exceed
 443          *    nsegments also when the maximum segment size is less
 444          *    than PAGE_SIZE.
 445          *  - The alignment constraint isn't larger than a page boundary.
 446          *  - There are no boundary-crossing constraints.
 447          * else allocate a block of contiguous pages because one or more of the
 448          * constraints is something that only the contig allocator can fulfill.
 449          *
 450          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 451          * below is just a quick hack. The exact alignment guarantees
 452          * of malloc(9) need to be nailed down, and the code below
 453          * should be rewritten to take that into account.
 454          *
 455          * In the meantime warn the user if malloc gets it wrong.
 456          */
 457         if (dmat->common.maxsize <= PAGE_SIZE &&
 458             dmat->common.alignment <= dmat->common.maxsize &&
 459             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 460             attr == VM_MEMATTR_DEFAULT) {
 461                 *vaddr = malloc_domainset(dmat->common.maxsize, M_DEVBUF,
 462                     DOMAINSET_PREF(dmat->common.domain), mflags);
 463         } else if (dmat->common.nsegments >=
 464             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz,
 465             PAGE_SIZE)) &&
 466             dmat->common.alignment <= PAGE_SIZE &&
 467             (dmat->common.boundary % PAGE_SIZE) == 0) {
 468                 /* Page-based multi-segment allocations allowed */
 469                 *vaddr = (void *)kmem_alloc_attr_domainset(
 470                     DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
 471                     mflags, 0ul, dmat->common.lowaddr, attr);
 472                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 473         } else {
 474                 *vaddr = (void *)kmem_alloc_contig_domainset(
 475                     DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
 476                     mflags, 0ul, dmat->common.lowaddr,
 477                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 478                     dmat->common.boundary, attr);
 479                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 480         }
 481         if (*vaddr == NULL) {
 482                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 483                     __func__, dmat, dmat->common.flags, ENOMEM);
 484                 return (ENOMEM);
 485         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 486                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 487         }
 488         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 489             __func__, dmat, dmat->common.flags, 0);
 490         return (0);
 491 }
 492
 493 /*
 494  * Free a piece of memory and it's allociated dmamap, that was allocated
 495  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 496  */
 497 static void
 498 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 499 {
 500         /*
 501          * dmamem does not need to be bounced, so the map should be
 502          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 503          * was used and set if kmem_alloc_contig() was used.
 504          */
 505         if (map != NULL)
 506                 panic("bus_dmamem_free: Invalid map freed\n");
 507         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 508                 free_domain(vaddr, M_DEVBUF);
 509         else
 510                 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 511         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 512             dmat->bounce_flags);
 513 }
 514
 515 static bool
 516 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
 517     int *pagesneeded)
 518 {
 519         vm_paddr_t curaddr;
 520         bus_size_t sgsize;
 521         int count;
 522
 523         /*
 524          * Count the number of bounce pages needed in order to
 525          * complete this transfer
 526          */
 527         count = 0;
 528         curaddr = buf;
 529         while (buflen != 0) {
 530                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 531                 if (bus_dma_run_filter(&dmat->common, curaddr)) {
 532                         sgsize = MIN(sgsize,
 533                             PAGE_SIZE - (curaddr & PAGE_MASK));
 534                         if (pagesneeded == NULL)
 535                                 return (true);
 536                         count++;
 537                 }
 538                 curaddr += sgsize;
 539                 buflen -= sgsize;
 540         }
 541
 542         if (pagesneeded != NULL)
 543                 *pagesneeded = count;
 544         return (count != 0);
 545 }
 546
 547 static void
 548 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 549     bus_size_t buflen, int flags)
 550 {
 551
 552         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 553                 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
 554                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 555         }
 556 }
 557
 558 static void
 559 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 560     void *buf, bus_size_t buflen, int flags)
 561 {
 562         vm_offset_t vaddr;
 563         vm_offset_t vendaddr;
 564         vm_paddr_t paddr;
 565         bus_size_t sg_len;
 566
 567         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 568                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 569                     "alignment= %d", dmat->common.lowaddr,
 570                     ptoa((vm_paddr_t)Maxmem),
 571                     dmat->common.boundary, dmat->common.alignment);
 572                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 573                     map, &nobounce_dmamap, map->pagesneeded);
 574                 /*
 575                  * Count the number of bounce pages
 576                  * needed in order to complete this transfer
 577                  */
 578                 vaddr = (vm_offset_t)buf;
 579                 vendaddr = (vm_offset_t)buf + buflen;
 580
 581                 while (vaddr < vendaddr) {
 582                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 583                         if (pmap == kernel_pmap)
 584                                 paddr = pmap_kextract(vaddr);
 585                         else
 586                                 paddr = pmap_extract(pmap, vaddr);
 587                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 588                                 sg_len = roundup2(sg_len,
 589                                     dmat->common.alignment);
 590                                 map->pagesneeded++;
 591                         }
 592                         vaddr += sg_len;
 593                 }
 594                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 595         }
 596 }
 597
 598 static void
 599 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 600     int ma_offs, bus_size_t buflen, int flags)
 601 {
 602         bus_size_t sg_len, max_sgsize;
 603         int page_index;
 604         vm_paddr_t paddr;
 605
 606         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 607                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 608                     "alignment= %d", dmat->common.lowaddr,
 609                     ptoa((vm_paddr_t)Maxmem),
 610                     dmat->common.boundary, dmat->common.alignment);
 611                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 612                     map, &nobounce_dmamap, map->pagesneeded);
 613
 614                 /*
 615                  * Count the number of bounce pages
 616                  * needed in order to complete this transfer
 617                  */
 618                 page_index = 0;
 619                 while (buflen > 0) {
 620                         paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 621                         sg_len = PAGE_SIZE - ma_offs;
 622                         max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 623                         sg_len = MIN(sg_len, max_sgsize);
 624                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 625                                 sg_len = roundup2(sg_len,
 626                                     dmat->common.alignment);
 627                                 sg_len = MIN(sg_len, max_sgsize);
 628                                 KASSERT((sg_len & (dmat->common.alignment - 1))
 629                                     == 0, ("Segment size is not aligned"));
 630                                 map->pagesneeded++;
 631                         }
 632                         if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
 633                                 page_index++;
 634                         ma_offs = (ma_offs + sg_len) & PAGE_MASK;
 635                         KASSERT(buflen >= sg_len,
 636                             ("Segment length overruns original buffer"));
 637                         buflen -= sg_len;
 638                 }
 639                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 640         }
 641 }
 642
 643 static int
 644 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 645 {
 646
 647         /* Reserve Necessary Bounce Pages */
 648         mtx_lock(&bounce_lock);
 649         if (flags & BUS_DMA_NOWAIT) {
 650                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 651                         mtx_unlock(&bounce_lock);
 652                         return (ENOMEM);
 653                 }
 654         } else {
 655                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 656                         /* Queue us for resources */
 657                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 658                         mtx_unlock(&bounce_lock);
 659                         return (EINPROGRESS);
 660                 }
 661         }
 662         mtx_unlock(&bounce_lock);
 663
 664         return (0);
 665 }
 666
 667 /*
 668  * Add a single contiguous physical range to the segment list.
 669  */
 670 static bus_size_t
 671 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t curaddr,
 672     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 673 {
 674         bus_addr_t baddr, bmask;
 675         int seg;
 676
 677         KASSERT(curaddr <= BUS_SPACE_MAXADDR,
 678             ("ds_addr %#jx > BUS_SPACE_MAXADDR %#jx; dmat %p fl %#x low %#jx "
 679             "hi %#jx",
 680             (uintmax_t)curaddr, (uintmax_t)BUS_SPACE_MAXADDR,
 681             dmat, dmat->bounce_flags, (uintmax_t)dmat->common.lowaddr,
 682             (uintmax_t)dmat->common.highaddr));
 683
 684         /*
 685          * Make sure we don't cross any boundaries.
 686          */
 687         bmask = ~(dmat->common.boundary - 1);
 688         if (dmat->common.boundary > 0) {
 689                 baddr = (curaddr + dmat->common.boundary) & bmask;
 690                 if (sgsize > (baddr - curaddr))
 691                         sgsize = (baddr - curaddr);
 692         }
 693
 694         /*
 695          * Insert chunk into a segment, coalescing with
 696          * previous segment if possible.
 697          */
 698         seg = *segp;
 699         if (seg == -1) {
 700                 seg = 0;
 701                 segs[seg].ds_addr = curaddr;
 702                 segs[seg].ds_len = sgsize;
 703         } else {
 704                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 705                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 706                     (dmat->common.boundary == 0 ||
 707                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 708                         segs[seg].ds_len += sgsize;
 709                 else {
 710                         if (++seg >= dmat->common.nsegments)
 711                                 return (0);
 712                         segs[seg].ds_addr = curaddr;
 713                         segs[seg].ds_len = sgsize;
 714                 }
 715         }
 716         *segp = seg;
 717         return (sgsize);
 718 }
 719
 720 /*
 721  * Utility function to load a physical buffer.  segp contains
 722  * the starting segment on entrace, and the ending segment on exit.
 723  */
 724 static int
 725 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 726     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 727     int *segp)
 728 {
 729         bus_size_t sgsize;
 730         vm_paddr_t curaddr;
 731         int error;
 732
 733         if (map == NULL)
 734                 map = &nobounce_dmamap;
 735
 736         if (segs == NULL)
 737                 segs = dmat->segments;
 738
 739         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 740                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 741                 if (map->pagesneeded != 0) {
 742                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 743                         if (error)
 744                                 return (error);
 745                 }
 746         }
 747
 748         while (buflen > 0) {
 749                 curaddr = buf;
 750                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 751                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 752                     map->pagesneeded != 0 &&
 753                     bus_dma_run_filter(&dmat->common, curaddr)) {
 754                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 755                         curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
 756                             sgsize);
 757                 }
 758                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 759                     segp);
 760                 if (sgsize == 0)
 761                         break;
 762                 buf += sgsize;
 763                 buflen -= sgsize;
 764         }
 765
 766         /*
 767          * Did we fit?
 768          */
 769         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 770 }
 771
 772 /*
 773  * Utility function to load a linear buffer.  segp contains
 774  * the starting segment on entrace, and the ending segment on exit.
 775  */
 776 static int
 777 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 778     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 779     int *segp)
 780 {
 781         bus_size_t sgsize, max_sgsize;
 782         vm_paddr_t curaddr;
 783         vm_offset_t kvaddr, vaddr;
 784         int error;
 785
 786         if (map == NULL)
 787                 map = &nobounce_dmamap;
 788
 789         if (segs == NULL)
 790                 segs = dmat->segments;
 791
 792         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 793                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 794                 if (map->pagesneeded != 0) {
 795                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 796                         if (error)
 797                                 return (error);
 798                 }
 799         }
 800
 801         vaddr = (vm_offset_t)buf;
 802         while (buflen > 0) {
 803                 /*
 804                  * Get the physical address for this segment.
 805                  */
 806                 if (pmap == kernel_pmap) {
 807                         curaddr = pmap_kextract(vaddr);
 808                         kvaddr = vaddr;
 809                 } else {
 810                         curaddr = pmap_extract(pmap, vaddr);
 811                         kvaddr = 0;
 812                 }
 813
 814                 /*
 815                  * Compute the segment size, and adjust counts.
 816                  */
 817                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 818                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 819                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 820                     map->pagesneeded != 0 &&
 821                     bus_dma_run_filter(&dmat->common, curaddr)) {
 822                         sgsize = roundup2(sgsize, dmat->common.alignment);
 823                         sgsize = MIN(sgsize, max_sgsize);
 824                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 825                             sgsize);
 826                 } else {
 827                         sgsize = MIN(sgsize, max_sgsize);
 828                 }
 829                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 830                     segp);
 831                 if (sgsize == 0)
 832                         break;
 833                 vaddr += sgsize;
 834                 buflen -= sgsize;
 835         }
 836
 837         /*
 838          * Did we fit?
 839          */
 840         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 841 }
 842
 843 static int
 844 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 845     struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
 846     bus_dma_segment_t *segs, int *segp)
 847 {
 848         vm_paddr_t paddr, next_paddr;
 849         int error, page_index;
 850         bus_size_t sgsize, max_sgsize;
 851
 852         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 853                 /*
 854                  * If we have to keep the offset of each page this function
 855                  * is not suitable, switch back to bus_dmamap_load_ma_triv
 856                  * which is going to do the right thing in this case.
 857                  */
 858                 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
 859                     flags, segs, segp);
 860                 return (error);
 861         }
 862
 863         if (map == NULL)
 864                 map = &nobounce_dmamap;
 865
 866         if (segs == NULL)
 867                 segs = dmat->segments;
 868
 869         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 870                 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
 871                 if (map->pagesneeded != 0) {
 872                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 873                         if (error)
 874                                 return (error);
 875                 }
 876         }
 877
 878         page_index = 0;
 879         while (buflen > 0) {
 880                 /*
 881                  * Compute the segment size, and adjust counts.
 882                  */
 883                 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 884                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 885                 sgsize = PAGE_SIZE - ma_offs;
 886                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 887                     map->pagesneeded != 0 &&
 888                     bus_dma_run_filter(&dmat->common, paddr)) {
 889                         sgsize = roundup2(sgsize, dmat->common.alignment);
 890                         sgsize = MIN(sgsize, max_sgsize);
 891                         KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
 892                             ("Segment size is not aligned"));
 893                         /*
 894                          * Check if two pages of the user provided buffer
 895                          * are used.
 896                          */
 897                         if ((ma_offs + sgsize) > PAGE_SIZE)
 898                                 next_paddr =
 899                                     VM_PAGE_TO_PHYS(ma[page_index + 1]);
 900                         else
 901                                 next_paddr = 0;
 902                         paddr = add_bounce_page(dmat, map, 0, paddr,
 903                             next_paddr, sgsize);
 904                 } else {
 905                         sgsize = MIN(sgsize, max_sgsize);
 906                 }
 907                 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
 908                     segp);
 909                 if (sgsize == 0)
 910                         break;
 911                 KASSERT(buflen >= sgsize,
 912                     ("Segment length overruns original buffer"));
 913                 buflen -= sgsize;
 914                 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
 915                         page_index++;
 916                 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
 917         }
 918
 919         /*
 920          * Did we fit?
 921          */
 922         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 923 }
 924
 925 static void
 926 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 927     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 928 {
 929
 930         if (map == NULL)
 931                 return;
 932         map->mem = *mem;
 933         map->dmat = dmat;
 934         map->callback = callback;
 935         map->callback_arg = callback_arg;
 936 }
 937
 938 static bus_dma_segment_t *
 939 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 940     bus_dma_segment_t *segs, int nsegs, int error)
 941 {
 942
 943         if (segs == NULL)
 944                 segs = dmat->segments;
 945         return (segs);
 946 }
 947
 948 /*
 949  * Release the mapping held by map.
 950  */
 951 static void
 952 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 953 {
 954         struct bounce_page *bpage;
 955
 956         if (map == NULL)
 957                 return;
 958
 959         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 960                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 961                 free_bounce_page(dmat, bpage);
 962         }
 963 }
 964
 965 static void
 966 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 967     bus_dmasync_op_t op)
 968 {
 969         struct bounce_page *bpage;
 970         vm_offset_t datavaddr, tempvaddr;
 971         bus_size_t datacount1, datacount2;
 972
 973         if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 974                 return;
 975
 976         /*
 977          * Handle data bouncing.  We might also want to add support for
 978          * invalidating the caches on broken hardware.
 979          */
 980         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 981             "performing bounce", __func__, dmat, dmat->common.flags, op);
 982
 983         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 984                 while (bpage != NULL) {
 985                         tempvaddr = 0;
 986                         datavaddr = bpage->datavaddr;
 987                         datacount1 = bpage->datacount;
 988                         if (datavaddr == 0) {
 989                                 tempvaddr =
 990                                     pmap_quick_enter_page(bpage->datapage[0]);
 991                                 datavaddr = tempvaddr | bpage->dataoffs;
 992                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 993                                     datacount1);
 994                         }
 995
 996                         bcopy((void *)datavaddr,
 997                             (void *)bpage->vaddr, datacount1);
 998
 999                         if (tempvaddr != 0)
1000                                 pmap_quick_remove_page(tempvaddr);
1001
1002                         if (bpage->datapage[1] == 0) {
1003                                 KASSERT(datacount1 == bpage->datacount,
1004                 ("Mismatch between data size and provided memory space"));
1005                                 goto next_w;
1006                         }
1007
1008                         /*
1009                          * We are dealing with an unmapped buffer that expands
1010                          * over two pages.
1011                          */
1012                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1013                         datacount2 = bpage->datacount - datacount1;
1014                         bcopy((void *)datavaddr,
1015                             (void *)(bpage->vaddr + datacount1), datacount2);
1016                         pmap_quick_remove_page(datavaddr);
1017
1018 next_w:
1019                         bpage = STAILQ_NEXT(bpage, links);
1020                 }
1021                 dmat->bounce_zone->total_bounced++;
1022         }
1023
1024         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1025                 while (bpage != NULL) {
1026                         tempvaddr = 0;
1027                         datavaddr = bpage->datavaddr;
1028                         datacount1 = bpage->datacount;
1029                         if (datavaddr == 0) {
1030                                 tempvaddr =
1031                                     pmap_quick_enter_page(bpage->datapage[0]);
1032                                 datavaddr = tempvaddr | bpage->dataoffs;
1033                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
1034                                     datacount1);
1035                         }
1036
1037                         bcopy((void *)bpage->vaddr, (void *)datavaddr,
1038                             datacount1);
1039
1040                         if (tempvaddr != 0)
1041                                 pmap_quick_remove_page(tempvaddr);
1042
1043                         if (bpage->datapage[1] == 0) {
1044                                 KASSERT(datacount1 == bpage->datacount,
1045                 ("Mismatch between data size and provided memory space"));
1046                                 goto next_r;
1047                         }
1048
1049                         /*
1050                          * We are dealing with an unmapped buffer that expands
1051                          * over two pages.
1052                          */
1053                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1054                         datacount2 = bpage->datacount - datacount1;
1055                         bcopy((void *)(bpage->vaddr + datacount1),
1056                             (void *)datavaddr, datacount2);
1057                         pmap_quick_remove_page(datavaddr);
1058
1059 next_r:
1060                         bpage = STAILQ_NEXT(bpage, links);
1061                 }
1062                 dmat->bounce_zone->total_bounced++;
1063         }
1064 }
1065
1066 static void
1067 init_bounce_pages(void *dummy __unused)
1068 {
1069
1070         total_bpages = 0;
1071         STAILQ_INIT(&bounce_zone_list);
1072         STAILQ_INIT(&bounce_map_waitinglist);
1073         STAILQ_INIT(&bounce_map_callbacklist);
1074         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1075 }
1076 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1077
1078 static struct sysctl_ctx_list *
1079 busdma_sysctl_tree(struct bounce_zone *bz)
1080 {
1081
1082         return (&bz->sysctl_tree);
1083 }
1084
1085 static struct sysctl_oid *
1086 busdma_sysctl_tree_top(struct bounce_zone *bz)
1087 {
1088
1089         return (bz->sysctl_tree_top);
1090 }
1091
1092 static int
1093 alloc_bounce_zone(bus_dma_tag_t dmat)
1094 {
1095         struct bounce_zone *bz;
1096
1097         /* Check to see if we already have a suitable zone */
1098         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1099                 if (dmat->common.alignment <= bz->alignment &&
1100                     dmat->common.lowaddr >= bz->lowaddr &&
1101                     dmat->common.domain == bz->domain) {
1102                         dmat->bounce_zone = bz;
1103                         return (0);
1104                 }
1105         }
1106
1107         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1108             M_NOWAIT | M_ZERO)) == NULL)
1109                 return (ENOMEM);
1110
1111         STAILQ_INIT(&bz->bounce_page_list);
1112         bz->free_bpages = 0;
1113         bz->reserved_bpages = 0;
1114         bz->active_bpages = 0;
1115         bz->lowaddr = dmat->common.lowaddr;
1116         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1117         bz->map_count = 0;
1118         bz->domain = dmat->common.domain;
1119         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1120         busdma_zonecount++;
1121         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1122         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1123         dmat->bounce_zone = bz;
1124
1125         sysctl_ctx_init(&bz->sysctl_tree);
1126         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1127             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1128             CTLFLAG_RD, 0, "");
1129         if (bz->sysctl_tree_top == NULL) {
1130                 sysctl_ctx_free(&bz->sysctl_tree);
1131                 return (0);     /* XXX error code? */
1132         }
1133
1134         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1135             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1136             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1137             "Total bounce pages");
1138         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1139             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1140             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1141             "Free bounce pages");
1142         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1143             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1144             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1145             "Reserved bounce pages");
1146         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1147             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1148             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1149             "Active bounce pages");
1150         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1151             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1152             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1153             "Total bounce requests");
1154         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1155             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1156             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1157             "Total bounce requests that were deferred");
1158         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1159             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1160             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1161         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1162             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1163             "alignment", CTLFLAG_RD, &bz->alignment, "");
1164         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1165             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1166             "domain", CTLFLAG_RD, &bz->domain, 0,
1167             "memory domain");
1168
1169         return (0);
1170 }
1171
1172 static int
1173 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1174 {
1175         struct bounce_zone *bz;
1176         int count;
1177
1178         bz = dmat->bounce_zone;
1179         count = 0;
1180         while (numpages > 0) {
1181                 struct bounce_page *bpage;
1182
1183                 bpage = malloc_domainset(sizeof(*bpage), M_DEVBUF,
1184                     DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
1185
1186                 if (bpage == NULL)
1187                         break;
1188                 bpage->vaddr = (vm_offset_t)contigmalloc_domainset(PAGE_SIZE,
1189                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT,
1190                     0ul, bz->lowaddr, PAGE_SIZE, 0);
1191                 if (bpage->vaddr == 0) {
1192                         free_domain(bpage, M_DEVBUF);
1193                         break;
1194                 }
1195                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1196                 mtx_lock(&bounce_lock);
1197                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1198                 total_bpages++;
1199                 bz->total_bpages++;
1200                 bz->free_bpages++;
1201                 mtx_unlock(&bounce_lock);
1202                 count++;
1203                 numpages--;
1204         }
1205         return (count);
1206 }
1207
1208 static int
1209 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1210 {
1211         struct bounce_zone *bz;
1212         int pages;
1213
1214         mtx_assert(&bounce_lock, MA_OWNED);
1215         bz = dmat->bounce_zone;
1216         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1217         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1218                 return (map->pagesneeded - (map->pagesreserved + pages));
1219         bz->free_bpages -= pages;
1220         bz->reserved_bpages += pages;
1221         map->pagesreserved += pages;
1222         pages = map->pagesneeded - map->pagesreserved;
1223
1224         return (pages);
1225 }
1226
1227 static bus_addr_t
1228 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1229     vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size)
1230 {
1231         struct bounce_zone *bz;
1232         struct bounce_page *bpage;
1233
1234         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1235         KASSERT(map != NULL && map != &nobounce_dmamap,
1236             ("add_bounce_page: bad map %p", map));
1237
1238         bz = dmat->bounce_zone;
1239         if (map->pagesneeded == 0)
1240                 panic("add_bounce_page: map doesn't need any pages");
1241         map->pagesneeded--;
1242
1243         if (map->pagesreserved == 0)
1244                 panic("add_bounce_page: map doesn't need any pages");
1245         map->pagesreserved--;
1246
1247         mtx_lock(&bounce_lock);
1248         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1249         if (bpage == NULL)
1250                 panic("add_bounce_page: free page list is empty");
1251
1252         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1253         bz->reserved_bpages--;
1254         bz->active_bpages++;
1255         mtx_unlock(&bounce_lock);
1256
1257         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1258                 /* Page offset needs to be preserved. */
1259                 bpage->vaddr |= addr1 & PAGE_MASK;
1260                 bpage->busaddr |= addr1 & PAGE_MASK;
1261                 KASSERT(addr2 == 0,
1262         ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1263         }
1264         bpage->datavaddr = vaddr;
1265         bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1266         KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1267         bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1268         bpage->dataoffs = addr1 & PAGE_MASK;
1269         bpage->datacount = size;
1270         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1271         return (bpage->busaddr);
1272 }
1273
1274 static void
1275 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1276 {
1277         struct bus_dmamap *map;
1278         struct bounce_zone *bz;
1279
1280         bz = dmat->bounce_zone;
1281         bpage->datavaddr = 0;
1282         bpage->datacount = 0;
1283         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1284                 /*
1285                  * Reset the bounce page to start at offset 0.  Other uses
1286                  * of this bounce page may need to store a full page of
1287                  * data and/or assume it starts on a page boundary.
1288                  */
1289                 bpage->vaddr &= ~PAGE_MASK;
1290                 bpage->busaddr &= ~PAGE_MASK;
1291         }
1292
1293         mtx_lock(&bounce_lock);
1294         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1295         bz->free_bpages++;
1296         bz->active_bpages--;
1297         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1298                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1299                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1300                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1301                             map, links);
1302                         busdma_swi_pending = 1;
1303                         bz->total_deferred++;
1304                         swi_sched(vm_ih, 0);
1305                 }
1306         }
1307         mtx_unlock(&bounce_lock);
1308 }
1309
1310 void
1311 busdma_swi(void)
1312 {
1313         bus_dma_tag_t dmat;
1314         struct bus_dmamap *map;
1315
1316         mtx_lock(&bounce_lock);
1317         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1318                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1319                 mtx_unlock(&bounce_lock);
1320                 dmat = map->dmat;
1321                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1322                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1323                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1324                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1325                     BUS_DMA_UNLOCK);
1326                 mtx_lock(&bounce_lock);
1327         }
1328         mtx_unlock(&bounce_lock);
1329 }
1330
1331 struct bus_dma_impl bus_dma_bounce_impl = {
1332         .tag_create = bounce_bus_dma_tag_create,
1333         .tag_destroy = bounce_bus_dma_tag_destroy,
1334         .tag_set_domain = bounce_bus_dma_tag_set_domain,
1335         .id_mapped = bounce_bus_dma_id_mapped,
1336         .map_create = bounce_bus_dmamap_create,
1337         .map_destroy = bounce_bus_dmamap_destroy,
1338         .mem_alloc = bounce_bus_dmamem_alloc,
1339         .mem_free = bounce_bus_dmamem_free,
1340         .load_phys = bounce_bus_dmamap_load_phys,
1341         .load_buffer = bounce_bus_dmamap_load_buffer,
1342         .load_ma = bounce_bus_dmamap_load_ma,
1343         .map_waitok = bounce_bus_dmamap_waitok,
1344         .map_complete = bounce_bus_dmamap_complete,
1345         .map_unload = bounce_bus_dmamap_unload,
1346         .map_sync = bounce_bus_dmamap_sync,
1347 };