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/malloc.h>
  35 #include <sys/bus.h>
  36 #include <sys/interrupt.h>
  37 #include <sys/kernel.h>
  38 #include <sys/ktr.h>
  39 #include <sys/lock.h>
  40 #include <sys/proc.h>
  41 #include <sys/memdesc.h>
  42 #include <sys/mutex.h>
  43 #include <sys/sysctl.h>
  44 #include <sys/uio.h>
  45
  46 #include <vm/vm.h>
  47 #include <vm/vm_extern.h>
  48 #include <vm/vm_kern.h>
  49 #include <vm/vm_page.h>
  50 #include <vm/vm_map.h>
  51
  52 #include <machine/atomic.h>
  53 #include <machine/bus.h>
  54 #include <machine/md_var.h>
  55 #include <machine/specialreg.h>
  56 #include <x86/include/busdma_impl.h>
  57
  58 #ifdef __i386__
  59 #define MAX_BPAGES 512
  60 #else
  61 #define MAX_BPAGES 8192
  62 #endif
  63
  64 enum {
  65         BUS_DMA_COULD_BOUNCE    = 0x01,
  66         BUS_DMA_MIN_ALLOC_COMP  = 0x02,
  67         BUS_DMA_KMEM_ALLOC      = 0x04,
  68 };
  69
  70 struct bounce_zone;
  71
  72 struct bus_dma_tag {
  73         struct bus_dma_tag_common common;
  74         int                     map_count;
  75         int                     bounce_flags;
  76         bus_dma_segment_t       *segments;
  77         struct bounce_zone      *bounce_zone;
  78 };
  79
  80 struct bounce_page {
  81         vm_offset_t     vaddr;          /* kva of bounce buffer */
  82         bus_addr_t      busaddr;        /* Physical address */
  83         vm_offset_t     datavaddr;      /* kva of client data */
  84         vm_offset_t     dataoffs;       /* page offset of client data */
  85         vm_page_t       datapage[2];    /* physical page(s) of client data */
  86         bus_size_t      datacount;      /* client data count */
  87         STAILQ_ENTRY(bounce_page) links;
  88 };
  89
  90 int busdma_swi_pending;
  91
  92 struct bounce_zone {
  93         STAILQ_ENTRY(bounce_zone) links;
  94         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  95         int             total_bpages;
  96         int             free_bpages;
  97         int             reserved_bpages;
  98         int             active_bpages;
  99         int             total_bounced;
 100         int             total_deferred;
 101         int             map_count;
 102         int             domain;
 103         bus_size_t      alignment;
 104         bus_addr_t      lowaddr;
 105         char            zoneid[8];
 106         char            lowaddrid[20];
 107         struct sysctl_ctx_list sysctl_tree;
 108         struct sysctl_oid *sysctl_tree_top;
 109 };
 110
 111 static struct mtx bounce_lock;
 112 static int total_bpages;
 113 static int busdma_zonecount;
 114 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
 115
 116 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 117 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 118            "Total bounce pages");
 119
 120 struct bus_dmamap {
 121         struct bp_list         bpages;
 122         int                    pagesneeded;
 123         int                    pagesreserved;
 124         bus_dma_tag_t          dmat;
 125         struct memdesc         mem;
 126         bus_dmamap_callback_t *callback;
 127         void                  *callback_arg;
 128         STAILQ_ENTRY(bus_dmamap) links;
 129 };
 130
 131 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 132 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 133 static struct bus_dmamap nobounce_dmamap;
 134
 135 static void init_bounce_pages(void *dummy);
 136 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 137 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 138 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 139                                 int commit);
 140 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 141                                   vm_offset_t vaddr, bus_addr_t addr1,
 142                                   bus_addr_t addr2, bus_size_t size);
 143 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 144 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 145 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 146                                     pmap_t pmap, void *buf, bus_size_t buflen,
 147                                     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,
 150                                    int flags);
 151 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 152                                      int flags);
 153
 154 static int
 155 bounce_bus_dma_zone_setup(bus_dma_tag_t dmat)
 156 {
 157         struct bounce_zone *bz;
 158         int error;
 159
 160         /* Must bounce */
 161         if ((error = alloc_bounce_zone(dmat)) != 0)
 162                 return (error);
 163         bz = dmat->bounce_zone;
 164
 165         if (ptoa(bz->total_bpages) < dmat->common.maxsize) {
 166                 int pages;
 167
 168                 pages = atop(dmat->common.maxsize) - bz->total_bpages;
 169
 170                 /* Add pages to our bounce pool */
 171                 if (alloc_bounce_pages(dmat, pages) < pages)
 172                         return (ENOMEM);
 173         }
 174         /* Performed initial allocation */
 175         dmat->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 176
 177         return (0);
 178 }
 179
 180 /*
 181  * Allocate a device specific dma_tag.
 182  */
 183 static int
 184 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 185     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 186     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 187     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 188     void *lockfuncarg, bus_dma_tag_t *dmat)
 189 {
 190         bus_dma_tag_t newtag;
 191         int error;
 192
 193         *dmat = NULL;
 194         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 195             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 196             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 197             sizeof (struct bus_dma_tag), (void **)&newtag);
 198         if (error != 0)
 199                 return (error);
 200
 201         newtag->common.impl = &bus_dma_bounce_impl;
 202         newtag->map_count = 0;
 203         newtag->segments = NULL;
 204
 205         if (parent != NULL && ((newtag->common.filter != NULL) ||
 206             ((parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0)))
 207                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 208
 209         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 210             newtag->common.alignment > 1)
 211                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 212
 213         if (((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 214             (flags & BUS_DMA_ALLOCNOW) != 0)
 215                 error = bounce_bus_dma_zone_setup(newtag);
 216         else
 217                 error = 0;
 218
 219         if (error != 0)
 220                 free(newtag, M_DEVBUF);
 221         else
 222                 *dmat = newtag;
 223         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 224             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 225             error);
 226         return (error);
 227 }
 228
 229 /*
 230  * Update the domain for the tag.  We may need to reallocate the zone and
 231  * bounce pages.
 232  */
 233 static int
 234 bounce_bus_dma_tag_set_domain(bus_dma_tag_t dmat)
 235 {
 236
 237         KASSERT(dmat->map_count == 0,
 238             ("bounce_bus_dma_tag_set_domain:  Domain set after use.\n"));
 239         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0 ||
 240             dmat->bounce_zone == NULL)
 241                 return (0);
 242         dmat->bounce_flags &= ~BUS_DMA_MIN_ALLOC_COMP;
 243         return (bounce_bus_dma_zone_setup(dmat));
 244 }
 245
 246 static int
 247 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 248 {
 249         bus_dma_tag_t dmat_copy, parent;
 250         int error;
 251
 252         error = 0;
 253         dmat_copy = dmat;
 254
 255         if (dmat != NULL) {
 256                 if (dmat->map_count != 0) {
 257                         error = EBUSY;
 258                         goto out;
 259                 }
 260                 while (dmat != NULL) {
 261                         parent = (bus_dma_tag_t)dmat->common.parent;
 262                         atomic_subtract_int(&dmat->common.ref_count, 1);
 263                         if (dmat->common.ref_count == 0) {
 264                                 if (dmat->segments != NULL)
 265                                         free_domain(dmat->segments, M_DEVBUF);
 266                                 free(dmat, M_DEVBUF);
 267                                 /*
 268                                  * Last reference count, so
 269                                  * release our reference
 270                                  * count on our parent.
 271                                  */
 272                                 dmat = parent;
 273                         } else
 274                                 dmat = NULL;
 275                 }
 276         }
 277 out:
 278         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 279         return (error);
 280 }
 281
 282 /*
 283  * Allocate a handle for mapping from kva/uva/physical
 284  * address space into bus device space.
 285  */
 286 static int
 287 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 288 {
 289         struct bounce_zone *bz;
 290         int error, maxpages, pages;
 291
 292         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
 293
 294         error = 0;
 295
 296         if (dmat->segments == NULL) {
 297                 dmat->segments = (bus_dma_segment_t *)malloc_domain(
 298                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 299                     M_DEVBUF, dmat->common.domain, M_NOWAIT);
 300                 if (dmat->segments == NULL) {
 301                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 302                             __func__, dmat, ENOMEM);
 303                         return (ENOMEM);
 304                 }
 305         }
 306
 307         /*
 308          * Bouncing might be required if the driver asks for an active
 309          * exclusion region, a data alignment that is stricter than 1, and/or
 310          * an active address boundary.
 311          */
 312         if (dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) {
 313                 /* Must bounce */
 314                 if (dmat->bounce_zone == NULL) {
 315                         if ((error = alloc_bounce_zone(dmat)) != 0)
 316                                 return (error);
 317                 }
 318                 bz = dmat->bounce_zone;
 319
 320                 *mapp = (bus_dmamap_t)malloc_domain(sizeof(**mapp), M_DEVBUF,
 321                     dmat->common.domain, M_NOWAIT | M_ZERO);
 322                 if (*mapp == NULL) {
 323                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 324                             __func__, dmat, ENOMEM);
 325                         return (ENOMEM);
 326                 }
 327
 328                 /* Initialize the new map */
 329                 STAILQ_INIT(&((*mapp)->bpages));
 330
 331                 /*
 332                  * Attempt to add pages to our pool on a per-instance
 333                  * basis up to a sane limit.
 334                  */
 335                 if (dmat->common.alignment > 1)
 336                         maxpages = MAX_BPAGES;
 337                 else
 338                         maxpages = MIN(MAX_BPAGES, Maxmem -
 339                             atop(dmat->common.lowaddr));
 340                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 341                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 342                         pages = MAX(atop(dmat->common.maxsize), 1);
 343                         pages = MIN(maxpages - bz->total_bpages, pages);
 344                         pages = MAX(pages, 1);
 345                         if (alloc_bounce_pages(dmat, pages) < pages)
 346                                 error = ENOMEM;
 347                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 348                             == 0) {
 349                                 if (error == 0) {
 350                                         dmat->bounce_flags |=
 351                                             BUS_DMA_MIN_ALLOC_COMP;
 352                                 }
 353                         } else
 354                                 error = 0;
 355                 }
 356                 bz->map_count++;
 357         } else {
 358                 *mapp = NULL;
 359         }
 360         if (error == 0)
 361                 dmat->map_count++;
 362         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 363             __func__, dmat, dmat->common.flags, error);
 364         return (error);
 365 }
 366
 367 /*
 368  * Destroy a handle for mapping from kva/uva/physical
 369  * address space into bus device space.
 370  */
 371 static int
 372 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 373 {
 374
 375         if (map != NULL && map != &nobounce_dmamap) {
 376                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 377                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 378                             __func__, dmat, EBUSY);
 379                         return (EBUSY);
 380                 }
 381                 if (dmat->bounce_zone)
 382                         dmat->bounce_zone->map_count--;
 383                 free_domain(map, M_DEVBUF);
 384         }
 385         dmat->map_count--;
 386         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 387         return (0);
 388 }
 389
 390
 391 /*
 392  * Allocate a piece of memory that can be efficiently mapped into
 393  * bus device space based on the constraints lited in the dma tag.
 394  * A dmamap to for use with dmamap_load is also allocated.
 395  */
 396 static int
 397 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 398     bus_dmamap_t *mapp)
 399 {
 400         vm_memattr_t attr;
 401         int mflags;
 402
 403         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
 404
 405         if (flags & BUS_DMA_NOWAIT)
 406                 mflags = M_NOWAIT;
 407         else
 408                 mflags = M_WAITOK;
 409
 410         /* If we succeed, no mapping/bouncing will be required */
 411         *mapp = NULL;
 412
 413         if (dmat->segments == NULL) {
 414                 dmat->segments = (bus_dma_segment_t *)malloc_domain(
 415                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 416                     M_DEVBUF, dmat->common.domain, mflags);
 417                 if (dmat->segments == NULL) {
 418                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 419                             __func__, dmat, dmat->common.flags, ENOMEM);
 420                         return (ENOMEM);
 421                 }
 422         }
 423         if (flags & BUS_DMA_ZERO)
 424                 mflags |= M_ZERO;
 425         if (flags & BUS_DMA_NOCACHE)
 426                 attr = VM_MEMATTR_UNCACHEABLE;
 427         else
 428                 attr = VM_MEMATTR_DEFAULT;
 429
 430         /*
 431          * Allocate the buffer from the malloc(9) allocator if...
 432          *  - It's small enough to fit into a single power of two sized bucket.
 433          *  - The alignment is less than or equal to the maximum size
 434          *  - The low address requirement is fulfilled.
 435          * else allocate non-contiguous pages if...
 436          *  - The page count that could get allocated doesn't exceed
 437          *    nsegments also when the maximum segment size is less
 438          *    than PAGE_SIZE.
 439          *  - The alignment constraint isn't larger than a page boundary.
 440          *  - There are no boundary-crossing constraints.
 441          * else allocate a block of contiguous pages because one or more of the
 442          * constraints is something that only the contig allocator can fulfill.
 443          *
 444          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 445          * below is just a quick hack. The exact alignment guarantees
 446          * of malloc(9) need to be nailed down, and the code below
 447          * should be rewritten to take that into account.
 448          *
 449          * In the meantime warn the user if malloc gets it wrong.
 450          */
 451         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 452            (dmat->common.alignment <= dmat->common.maxsize) &&
 453             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 454             attr == VM_MEMATTR_DEFAULT) {
 455                 *vaddr = malloc_domain(dmat->common.maxsize, M_DEVBUF,
 456                     dmat->common.domain, mflags);
 457         } else if (dmat->common.nsegments >=
 458             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
 459             dmat->common.alignment <= PAGE_SIZE &&
 460             (dmat->common.boundary % PAGE_SIZE) == 0) {
 461                 /* Page-based multi-segment allocations allowed */
 462                 *vaddr = (void *)kmem_alloc_attr_domain(dmat->common.domain,
 463                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 464                     attr);
 465                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 466         } else {
 467                 *vaddr = (void *)kmem_alloc_contig_domain(dmat->common.domain,
 468                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 469                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 470                     dmat->common.boundary, attr);
 471                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 472         }
 473         if (*vaddr == NULL) {
 474                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 475                     __func__, dmat, dmat->common.flags, ENOMEM);
 476                 return (ENOMEM);
 477         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 478                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 479         }
 480         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 481             __func__, dmat, dmat->common.flags, 0);
 482         return (0);
 483 }
 484
 485 /*
 486  * Free a piece of memory and it's allociated dmamap, that was allocated
 487  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 488  */
 489 static void
 490 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 491 {
 492         /*
 493          * dmamem does not need to be bounced, so the map should be
 494          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 495          * was used and set if kmem_alloc_contig() was used.
 496          */
 497         if (map != NULL)
 498                 panic("bus_dmamem_free: Invalid map freed\n");
 499         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 500                 free_domain(vaddr, M_DEVBUF);
 501         else
 502                 kmem_free(kernel_arena, (vm_offset_t)vaddr,
 503                     dmat->common.maxsize);
 504         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 505             dmat->bounce_flags);
 506 }
 507
 508 static void
 509 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 510     bus_size_t buflen, int flags)
 511 {
 512         bus_addr_t curaddr;
 513         bus_size_t sgsize;
 514
 515         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 516                 /*
 517                  * Count the number of bounce pages
 518                  * needed in order to complete this transfer
 519                  */
 520                 curaddr = buf;
 521                 while (buflen != 0) {
 522                         sgsize = MIN(buflen, dmat->common.maxsegsz);
 523                         if (bus_dma_run_filter(&dmat->common, curaddr)) {
 524                                 sgsize = MIN(sgsize,
 525                                     PAGE_SIZE - (curaddr & PAGE_MASK));
 526                                 map->pagesneeded++;
 527                         }
 528                         curaddr += sgsize;
 529                         buflen -= sgsize;
 530                 }
 531                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 532         }
 533 }
 534
 535 static void
 536 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 537     void *buf, bus_size_t buflen, int flags)
 538 {
 539         vm_offset_t vaddr;
 540         vm_offset_t vendaddr;
 541         bus_addr_t paddr;
 542         bus_size_t sg_len;
 543
 544         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 545                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 546                     "alignment= %d", dmat->common.lowaddr,
 547                     ptoa((vm_paddr_t)Maxmem),
 548                     dmat->common.boundary, dmat->common.alignment);
 549                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 550                     map, &nobounce_dmamap, map->pagesneeded);
 551                 /*
 552                  * Count the number of bounce pages
 553                  * needed in order to complete this transfer
 554                  */
 555                 vaddr = (vm_offset_t)buf;
 556                 vendaddr = (vm_offset_t)buf + buflen;
 557
 558                 while (vaddr < vendaddr) {
 559                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 560                         if (pmap == kernel_pmap)
 561                                 paddr = pmap_kextract(vaddr);
 562                         else
 563                                 paddr = pmap_extract(pmap, vaddr);
 564                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 565                                 sg_len = roundup2(sg_len,
 566                                     dmat->common.alignment);
 567                                 map->pagesneeded++;
 568                         }
 569                         vaddr += sg_len;
 570                 }
 571                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 572         }
 573 }
 574
 575 static void
 576 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 577     int ma_offs, bus_size_t buflen, int flags)
 578 {
 579         bus_size_t sg_len, max_sgsize;
 580         int page_index;
 581         vm_paddr_t paddr;
 582
 583         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 584                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 585                     "alignment= %d", dmat->common.lowaddr,
 586                     ptoa((vm_paddr_t)Maxmem),
 587                     dmat->common.boundary, dmat->common.alignment);
 588                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 589                     map, &nobounce_dmamap, map->pagesneeded);
 590
 591                 /*
 592                  * Count the number of bounce pages
 593                  * needed in order to complete this transfer
 594                  */
 595                 page_index = 0;
 596                 while (buflen > 0) {
 597                         paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 598                         sg_len = PAGE_SIZE - ma_offs;
 599                         max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 600                         sg_len = MIN(sg_len, max_sgsize);
 601                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 602                                 sg_len = roundup2(sg_len,
 603                                     dmat->common.alignment);
 604                                 sg_len = MIN(sg_len, max_sgsize);
 605                                 KASSERT((sg_len & (dmat->common.alignment - 1))
 606                                     == 0, ("Segment size is not aligned"));
 607                                 map->pagesneeded++;
 608                         }
 609                         if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
 610                                 page_index++;
 611                         ma_offs = (ma_offs + sg_len) & PAGE_MASK;
 612                         KASSERT(buflen >= sg_len,
 613                             ("Segment length overruns original buffer"));
 614                         buflen -= sg_len;
 615                 }
 616                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 617         }
 618 }
 619
 620 static int
 621 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 622 {
 623
 624         /* Reserve Necessary Bounce Pages */
 625         mtx_lock(&bounce_lock);
 626         if (flags & BUS_DMA_NOWAIT) {
 627                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 628                         mtx_unlock(&bounce_lock);
 629                         return (ENOMEM);
 630                 }
 631         } else {
 632                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 633                         /* Queue us for resources */
 634                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 635                         mtx_unlock(&bounce_lock);
 636                         return (EINPROGRESS);
 637                 }
 638         }
 639         mtx_unlock(&bounce_lock);
 640
 641         return (0);
 642 }
 643
 644 /*
 645  * Add a single contiguous physical range to the segment list.
 646  */
 647 static int
 648 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 649     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 650 {
 651         bus_addr_t baddr, bmask;
 652         int seg;
 653
 654         /*
 655          * Make sure we don't cross any boundaries.
 656          */
 657         bmask = ~(dmat->common.boundary - 1);
 658         if (dmat->common.boundary > 0) {
 659                 baddr = (curaddr + dmat->common.boundary) & bmask;
 660                 if (sgsize > (baddr - curaddr))
 661                         sgsize = (baddr - curaddr);
 662         }
 663
 664         /*
 665          * Insert chunk into a segment, coalescing with
 666          * previous segment if possible.
 667          */
 668         seg = *segp;
 669         if (seg == -1) {
 670                 seg = 0;
 671                 segs[seg].ds_addr = curaddr;
 672                 segs[seg].ds_len = sgsize;
 673         } else {
 674                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 675                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 676                     (dmat->common.boundary == 0 ||
 677                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 678                         segs[seg].ds_len += sgsize;
 679                 else {
 680                         if (++seg >= dmat->common.nsegments)
 681                                 return (0);
 682                         segs[seg].ds_addr = curaddr;
 683                         segs[seg].ds_len = sgsize;
 684                 }
 685         }
 686         *segp = seg;
 687         return (sgsize);
 688 }
 689
 690 /*
 691  * Utility function to load a physical buffer.  segp contains
 692  * the starting segment on entrace, and the ending segment on exit.
 693  */
 694 static int
 695 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 696     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 697     int *segp)
 698 {
 699         bus_size_t sgsize;
 700         bus_addr_t curaddr;
 701         int error;
 702
 703         if (map == NULL)
 704                 map = &nobounce_dmamap;
 705
 706         if (segs == NULL)
 707                 segs = dmat->segments;
 708
 709         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 710                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 711                 if (map->pagesneeded != 0) {
 712                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 713                         if (error)
 714                                 return (error);
 715                 }
 716         }
 717
 718         while (buflen > 0) {
 719                 curaddr = buf;
 720                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 721                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 722                     map->pagesneeded != 0 &&
 723                     bus_dma_run_filter(&dmat->common, curaddr)) {
 724                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 725                         curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
 726                             sgsize);
 727                 }
 728                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 729                     segp);
 730                 if (sgsize == 0)
 731                         break;
 732                 buf += sgsize;
 733                 buflen -= sgsize;
 734         }
 735
 736         /*
 737          * Did we fit?
 738          */
 739         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 740 }
 741
 742 /*
 743  * Utility function to load a linear buffer.  segp contains
 744  * the starting segment on entrace, and the ending segment on exit.
 745  */
 746 static int
 747 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 748     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 749     int *segp)
 750 {
 751         bus_size_t sgsize, max_sgsize;
 752         bus_addr_t curaddr;
 753         vm_offset_t kvaddr, vaddr;
 754         int error;
 755
 756         if (map == NULL)
 757                 map = &nobounce_dmamap;
 758
 759         if (segs == NULL)
 760                 segs = dmat->segments;
 761
 762         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 763                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 764                 if (map->pagesneeded != 0) {
 765                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 766                         if (error)
 767                                 return (error);
 768                 }
 769         }
 770
 771         vaddr = (vm_offset_t)buf;
 772         while (buflen > 0) {
 773                 /*
 774                  * Get the physical address for this segment.
 775                  */
 776                 if (pmap == kernel_pmap) {
 777                         curaddr = pmap_kextract(vaddr);
 778                         kvaddr = vaddr;
 779                 } else {
 780                         curaddr = pmap_extract(pmap, vaddr);
 781                         kvaddr = 0;
 782                 }
 783
 784                 /*
 785                  * Compute the segment size, and adjust counts.
 786                  */
 787                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 788                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 789                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 790                     map->pagesneeded != 0 &&
 791                     bus_dma_run_filter(&dmat->common, curaddr)) {
 792                         sgsize = roundup2(sgsize, dmat->common.alignment);
 793                         sgsize = MIN(sgsize, max_sgsize);
 794                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 795                             sgsize);
 796                 } else {
 797                         sgsize = MIN(sgsize, max_sgsize);
 798                 }
 799                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 800                     segp);
 801                 if (sgsize == 0)
 802                         break;
 803                 vaddr += sgsize;
 804                 buflen -= sgsize;
 805         }
 806
 807         /*
 808          * Did we fit?
 809          */
 810         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 811 }
 812
 813 static int
 814 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 815     struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
 816     bus_dma_segment_t *segs, int *segp)
 817 {
 818         vm_paddr_t paddr, next_paddr;
 819         int error, page_index;
 820         bus_size_t sgsize, max_sgsize;
 821
 822         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 823                 /*
 824                  * If we have to keep the offset of each page this function
 825                  * is not suitable, switch back to bus_dmamap_load_ma_triv
 826                  * which is going to do the right thing in this case.
 827                  */
 828                 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
 829                     flags, segs, segp);
 830                 return (error);
 831         }
 832
 833         if (map == NULL)
 834                 map = &nobounce_dmamap;
 835
 836         if (segs == NULL)
 837                 segs = dmat->segments;
 838
 839         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 840                 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
 841                 if (map->pagesneeded != 0) {
 842                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 843                         if (error)
 844                                 return (error);
 845                 }
 846         }
 847
 848         page_index = 0;
 849         while (buflen > 0) {
 850                 /*
 851                  * Compute the segment size, and adjust counts.
 852                  */
 853                 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 854                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 855                 sgsize = PAGE_SIZE - ma_offs;
 856                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 857                     map->pagesneeded != 0 &&
 858                     bus_dma_run_filter(&dmat->common, paddr)) {
 859                         sgsize = roundup2(sgsize, dmat->common.alignment);
 860                         sgsize = MIN(sgsize, max_sgsize);
 861                         KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
 862                             ("Segment size is not aligned"));
 863                         /*
 864                          * Check if two pages of the user provided buffer
 865                          * are used.
 866                          */
 867                         if ((ma_offs + sgsize) > PAGE_SIZE)
 868                                 next_paddr =
 869                                     VM_PAGE_TO_PHYS(ma[page_index + 1]);
 870                         else
 871                                 next_paddr = 0;
 872                         paddr = add_bounce_page(dmat, map, 0, paddr,
 873                             next_paddr, sgsize);
 874                 } else {
 875                         sgsize = MIN(sgsize, max_sgsize);
 876                 }
 877                 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
 878                     segp);
 879                 if (sgsize == 0)
 880                         break;
 881                 KASSERT(buflen >= sgsize,
 882                     ("Segment length overruns original buffer"));
 883                 buflen -= sgsize;
 884                 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
 885                         page_index++;
 886                 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
 887         }
 888
 889         /*
 890          * Did we fit?
 891          */
 892         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 893 }
 894
 895 static void
 896 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 897     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 898 {
 899
 900         if (map == NULL)
 901                 return;
 902         map->mem = *mem;
 903         map->dmat = dmat;
 904         map->callback = callback;
 905         map->callback_arg = callback_arg;
 906 }
 907
 908 static bus_dma_segment_t *
 909 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 910     bus_dma_segment_t *segs, int nsegs, int error)
 911 {
 912
 913         if (segs == NULL)
 914                 segs = dmat->segments;
 915         return (segs);
 916 }
 917
 918 /*
 919  * Release the mapping held by map.
 920  */
 921 static void
 922 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 923 {
 924         struct bounce_page *bpage;
 925
 926         if (map == NULL)
 927                 return;
 928
 929         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 930                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 931                 free_bounce_page(dmat, bpage);
 932         }
 933 }
 934
 935 static void
 936 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 937     bus_dmasync_op_t op)
 938 {
 939         struct bounce_page *bpage;
 940         vm_offset_t datavaddr, tempvaddr;
 941         bus_size_t datacount1, datacount2;
 942
 943         if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 944                 return;
 945
 946         /*
 947          * Handle data bouncing.  We might also want to add support for
 948          * invalidating the caches on broken hardware.
 949          */
 950         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 951             "performing bounce", __func__, dmat, dmat->common.flags, op);
 952
 953         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 954                 while (bpage != NULL) {
 955                         tempvaddr = 0;
 956                         datavaddr = bpage->datavaddr;
 957                         datacount1 = bpage->datacount;
 958                         if (datavaddr == 0) {
 959                                 tempvaddr =
 960                                     pmap_quick_enter_page(bpage->datapage[0]);
 961                                 datavaddr = tempvaddr | bpage->dataoffs;
 962                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 963                                     datacount1);
 964                         }
 965
 966                         bcopy((void *)datavaddr,
 967                             (void *)bpage->vaddr, datacount1);
 968
 969                         if (tempvaddr != 0)
 970                                 pmap_quick_remove_page(tempvaddr);
 971
 972                         if (bpage->datapage[1] == 0) {
 973                                 KASSERT(datacount1 == bpage->datacount,
 974                 ("Mismatch between data size and provided memory space"));
 975                                 goto next_w;
 976                         }
 977
 978                         /*
 979                          * We are dealing with an unmapped buffer that expands
 980                          * over two pages.
 981                          */
 982                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
 983                         datacount2 = bpage->datacount - datacount1;
 984                         bcopy((void *)datavaddr,
 985                             (void *)(bpage->vaddr + datacount1), datacount2);
 986                         pmap_quick_remove_page(datavaddr);
 987
 988 next_w:
 989                         bpage = STAILQ_NEXT(bpage, links);
 990                 }
 991                 dmat->bounce_zone->total_bounced++;
 992         }
 993
 994         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
 995                 while (bpage != NULL) {
 996                         tempvaddr = 0;
 997                         datavaddr = bpage->datavaddr;
 998                         datacount1 = bpage->datacount;
 999                         if (datavaddr == 0) {
1000                                 tempvaddr =
1001                                     pmap_quick_enter_page(bpage->datapage[0]);
1002                                 datavaddr = tempvaddr | bpage->dataoffs;
1003                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
1004                                     datacount1);
1005                         }
1006
1007                         bcopy((void *)bpage->vaddr, (void *)datavaddr,
1008                             datacount1);
1009
1010                         if (tempvaddr != 0)
1011                                 pmap_quick_remove_page(tempvaddr);
1012
1013                         if (bpage->datapage[1] == 0) {
1014                                 KASSERT(datacount1 == bpage->datacount,
1015                 ("Mismatch between data size and provided memory space"));
1016                                 goto next_r;
1017                         }
1018
1019                         /*
1020                          * We are dealing with an unmapped buffer that expands
1021                          * over two pages.
1022                          */
1023                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1024                         datacount2 = bpage->datacount - datacount1;
1025                         bcopy((void *)(bpage->vaddr + datacount1),
1026                             (void *)datavaddr, datacount2);
1027                         pmap_quick_remove_page(datavaddr);
1028
1029 next_r:
1030                         bpage = STAILQ_NEXT(bpage, links);
1031                 }
1032                 dmat->bounce_zone->total_bounced++;
1033         }
1034 }
1035
1036 static void
1037 init_bounce_pages(void *dummy __unused)
1038 {
1039
1040         total_bpages = 0;
1041         STAILQ_INIT(&bounce_zone_list);
1042         STAILQ_INIT(&bounce_map_waitinglist);
1043         STAILQ_INIT(&bounce_map_callbacklist);
1044         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1045 }
1046 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1047
1048 static struct sysctl_ctx_list *
1049 busdma_sysctl_tree(struct bounce_zone *bz)
1050 {
1051
1052         return (&bz->sysctl_tree);
1053 }
1054
1055 static struct sysctl_oid *
1056 busdma_sysctl_tree_top(struct bounce_zone *bz)
1057 {
1058
1059         return (bz->sysctl_tree_top);
1060 }
1061
1062 static int
1063 alloc_bounce_zone(bus_dma_tag_t dmat)
1064 {
1065         struct bounce_zone *bz;
1066
1067         /* Check to see if we already have a suitable zone */
1068         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1069                 if ((dmat->common.alignment <= bz->alignment) &&
1070                     (dmat->common.lowaddr >= bz->lowaddr) &&
1071                     (dmat->common.domain == bz->domain)) {
1072                         dmat->bounce_zone = bz;
1073                         return (0);
1074                 }
1075         }
1076
1077         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1078             M_NOWAIT | M_ZERO)) == NULL)
1079                 return (ENOMEM);
1080
1081         STAILQ_INIT(&bz->bounce_page_list);
1082         bz->free_bpages = 0;
1083         bz->reserved_bpages = 0;
1084         bz->active_bpages = 0;
1085         bz->lowaddr = dmat->common.lowaddr;
1086         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1087         bz->map_count = 0;
1088         bz->domain = dmat->common.domain;
1089         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1090         busdma_zonecount++;
1091         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1092         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1093         dmat->bounce_zone = bz;
1094
1095         sysctl_ctx_init(&bz->sysctl_tree);
1096         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1097             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1098             CTLFLAG_RD, 0, "");
1099         if (bz->sysctl_tree_top == NULL) {
1100                 sysctl_ctx_free(&bz->sysctl_tree);
1101                 return (0);     /* XXX error code? */
1102         }
1103
1104         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1105             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1106             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1107             "Total bounce pages");
1108         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1109             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1110             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1111             "Free bounce pages");
1112         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1113             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1114             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1115             "Reserved bounce pages");
1116         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1117             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1118             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1119             "Active bounce pages");
1120         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1121             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1122             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1123             "Total bounce requests");
1124         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1125             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1126             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1127             "Total bounce requests that were deferred");
1128         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1129             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1130             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1131         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1132             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1133             "alignment", CTLFLAG_RD, &bz->alignment, "");
1134         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1135             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1136             "domain", CTLFLAG_RD, &bz->domain, 0,
1137             "memory domain");
1138
1139         return (0);
1140 }
1141
1142 static int
1143 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1144 {
1145         struct bounce_zone *bz;
1146         int count;
1147
1148         bz = dmat->bounce_zone;
1149         count = 0;
1150         while (numpages > 0) {
1151                 struct bounce_page *bpage;
1152
1153                 bpage = (struct bounce_page *)malloc_domain(sizeof(*bpage),
1154                     M_DEVBUF, dmat->common.domain, M_NOWAIT | M_ZERO);
1155
1156                 if (bpage == NULL)
1157                         break;
1158                 bpage->vaddr = (vm_offset_t)contigmalloc_domain(PAGE_SIZE,
1159                     M_DEVBUF, dmat->common.domain, M_NOWAIT, 0ul,
1160                     bz->lowaddr, PAGE_SIZE, 0);
1161                 if (bpage->vaddr == 0) {
1162                         free_domain(bpage, M_DEVBUF);
1163                         break;
1164                 }
1165                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1166                 mtx_lock(&bounce_lock);
1167                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1168                 total_bpages++;
1169                 bz->total_bpages++;
1170                 bz->free_bpages++;
1171                 mtx_unlock(&bounce_lock);
1172                 count++;
1173                 numpages--;
1174         }
1175         return (count);
1176 }
1177
1178 static int
1179 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1180 {
1181         struct bounce_zone *bz;
1182         int pages;
1183
1184         mtx_assert(&bounce_lock, MA_OWNED);
1185         bz = dmat->bounce_zone;
1186         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1187         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1188                 return (map->pagesneeded - (map->pagesreserved + pages));
1189         bz->free_bpages -= pages;
1190         bz->reserved_bpages += pages;
1191         map->pagesreserved += pages;
1192         pages = map->pagesneeded - map->pagesreserved;
1193
1194         return (pages);
1195 }
1196
1197 static bus_addr_t
1198 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1199                 bus_addr_t addr1, bus_addr_t addr2, bus_size_t size)
1200 {
1201         struct bounce_zone *bz;
1202         struct bounce_page *bpage;
1203
1204         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1205         KASSERT(map != NULL && map != &nobounce_dmamap,
1206             ("add_bounce_page: bad map %p", map));
1207
1208         bz = dmat->bounce_zone;
1209         if (map->pagesneeded == 0)
1210                 panic("add_bounce_page: map doesn't need any pages");
1211         map->pagesneeded--;
1212
1213         if (map->pagesreserved == 0)
1214                 panic("add_bounce_page: map doesn't need any pages");
1215         map->pagesreserved--;
1216
1217         mtx_lock(&bounce_lock);
1218         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1219         if (bpage == NULL)
1220                 panic("add_bounce_page: free page list is empty");
1221
1222         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1223         bz->reserved_bpages--;
1224         bz->active_bpages++;
1225         mtx_unlock(&bounce_lock);
1226
1227         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1228                 /* Page offset needs to be preserved. */
1229                 bpage->vaddr |= addr1 & PAGE_MASK;
1230                 bpage->busaddr |= addr1 & PAGE_MASK;
1231                 KASSERT(addr2 == 0,
1232         ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1233         }
1234         bpage->datavaddr = vaddr;
1235         bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1236         KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1237         bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1238         bpage->dataoffs = addr1 & PAGE_MASK;
1239         bpage->datacount = size;
1240         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1241         return (bpage->busaddr);
1242 }
1243
1244 static void
1245 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1246 {
1247         struct bus_dmamap *map;
1248         struct bounce_zone *bz;
1249
1250         bz = dmat->bounce_zone;
1251         bpage->datavaddr = 0;
1252         bpage->datacount = 0;
1253         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1254                 /*
1255                  * Reset the bounce page to start at offset 0.  Other uses
1256                  * of this bounce page may need to store a full page of
1257                  * data and/or assume it starts on a page boundary.
1258                  */
1259                 bpage->vaddr &= ~PAGE_MASK;
1260                 bpage->busaddr &= ~PAGE_MASK;
1261         }
1262
1263         mtx_lock(&bounce_lock);
1264         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1265         bz->free_bpages++;
1266         bz->active_bpages--;
1267         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1268                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1269                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1270                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1271                             map, links);
1272                         busdma_swi_pending = 1;
1273                         bz->total_deferred++;
1274                         swi_sched(vm_ih, 0);
1275                 }
1276         }
1277         mtx_unlock(&bounce_lock);
1278 }
1279
1280 void
1281 busdma_swi(void)
1282 {
1283         bus_dma_tag_t dmat;
1284         struct bus_dmamap *map;
1285
1286         mtx_lock(&bounce_lock);
1287         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1288                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1289                 mtx_unlock(&bounce_lock);
1290                 dmat = map->dmat;
1291                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1292                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1293                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1294                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1295                     BUS_DMA_UNLOCK);
1296                 mtx_lock(&bounce_lock);
1297         }
1298         mtx_unlock(&bounce_lock);
1299 }
1300
1301 struct bus_dma_impl bus_dma_bounce_impl = {
1302         .tag_create = bounce_bus_dma_tag_create,
1303         .tag_destroy = bounce_bus_dma_tag_destroy,
1304         .tag_set_domain = bounce_bus_dma_tag_set_domain,
1305         .map_create = bounce_bus_dmamap_create,
1306         .map_destroy = bounce_bus_dmamap_destroy,
1307         .mem_alloc = bounce_bus_dmamem_alloc,
1308         .mem_free = bounce_bus_dmamem_free,
1309         .load_phys = bounce_bus_dmamap_load_phys,
1310         .load_buffer = bounce_bus_dmamap_load_buffer,
1311         .load_ma = bounce_bus_dmamap_load_ma,
1312         .map_waitok = bounce_bus_dmamap_waitok,
1313         .map_complete = bounce_bus_dmamap_complete,
1314         .map_unload = bounce_bus_dmamap_unload,
1315         .map_sync = bounce_bus_dmamap_sync,
1316 };