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