sys/x86/x86/busdma_bounce.c

   1 /*-
   2  * Copyright (c) 1997, 1998 Justin T. Gibbs.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions, and the following disclaimer,
  10  *    without modification, immediately at the beginning of the file.
  11  * 2. The name of the author may not be used to endorse or promote products
  12  *    derived from this software without specific prior written permission.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  18  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/malloc.h>
  33 #include <sys/bus.h>
  34 #include <sys/interrupt.h>
  35 #include <sys/kernel.h>
  36 #include <sys/ktr.h>
  37 #include <sys/lock.h>
  38 #include <sys/proc.h>
  39 #include <sys/memdesc.h>
  40 #include <sys/mutex.h>
  41 #include <sys/sysctl.h>
  42 #include <sys/uio.h>
  43
  44 #include <vm/vm.h>
  45 #include <vm/vm_extern.h>
  46 #include <vm/vm_kern.h>
  47 #include <vm/vm_page.h>
  48 #include <vm/vm_map.h>
  49
  50 #include <machine/atomic.h>
  51 #include <machine/bus.h>
  52 #include <machine/md_var.h>
  53 #include <machine/specialreg.h>
  54 #include <x86/include/busdma_impl.h>
  55
  56 #ifdef __i386__
  57 #define MAX_BPAGES 512
  58 #else
  59 #define MAX_BPAGES 8192
  60 #endif
  61
  62 enum {
  63         BUS_DMA_COULD_BOUNCE    = 0x01,
  64         BUS_DMA_MIN_ALLOC_COMP  = 0x02,
  65         BUS_DMA_KMEM_ALLOC      = 0x04,
  66 };
  67
  68 struct bounce_zone;
  69
  70 struct bus_dma_tag {
  71         struct bus_dma_tag_common common;
  72         int                     map_count;
  73         int                     bounce_flags;
  74         bus_dma_segment_t       *segments;
  75         struct bounce_zone      *bounce_zone;
  76 };
  77
  78 struct bounce_page {
  79         vm_offset_t     vaddr;          /* kva of bounce buffer */
  80         bus_addr_t      busaddr;        /* Physical address */
  81         vm_offset_t     datavaddr;      /* kva of client data */
  82         vm_offset_t     dataoffs;       /* page offset of client data */
  83         vm_page_t       datapage[2];    /* physical page(s) of client data */
  84         bus_size_t      datacount;      /* client data count */
  85         STAILQ_ENTRY(bounce_page) links;
  86 };
  87
  88 int busdma_swi_pending;
  89
  90 struct bounce_zone {
  91         STAILQ_ENTRY(bounce_zone) links;
  92         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  93         int             total_bpages;
  94         int             free_bpages;
  95         int             reserved_bpages;
  96         int             active_bpages;
  97         int             total_bounced;
  98         int             total_deferred;
  99         int             map_count;
 100         bus_size_t      alignment;
 101         bus_addr_t      lowaddr;
 102         char            zoneid[8];
 103         char            lowaddrid[20];
 104         struct sysctl_ctx_list sysctl_tree;
 105         struct sysctl_oid *sysctl_tree_top;
 106 };
 107
 108 static struct mtx bounce_lock;
 109 static int total_bpages;
 110 static int busdma_zonecount;
 111 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
 112
 113 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 114 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 115            "Total bounce pages");
 116
 117 struct bus_dmamap {
 118         struct bp_list         bpages;
 119         int                    pagesneeded;
 120         int                    pagesreserved;
 121         bus_dma_tag_t          dmat;
 122         struct memdesc         mem;
 123         bus_dmamap_callback_t *callback;
 124         void                  *callback_arg;
 125         STAILQ_ENTRY(bus_dmamap) links;
 126 };
 127
 128 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 129 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 130 static struct bus_dmamap nobounce_dmamap;
 131
 132 static void init_bounce_pages(void *dummy);
 133 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 134 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 135 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 136                                 int commit);
 137 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 138                                   vm_offset_t vaddr, bus_addr_t addr1,
 139                                   bus_addr_t addr2, bus_size_t size);
 140 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 141 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 142 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 143                                     pmap_t pmap, void *buf, bus_size_t buflen,
 144                                     int flags);
 145 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 146                                    vm_paddr_t buf, bus_size_t buflen,
 147                                    int flags);
 148 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 149                                      int flags);
 150
 151 /*
 152  * Allocate a device specific dma_tag.
 153  */
 154 static int
 155 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 156     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 157     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 158     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 159     void *lockfuncarg, bus_dma_tag_t *dmat)
 160 {
 161         bus_dma_tag_t newtag;
 162         int error;
 163
 164         *dmat = NULL;
 165         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 166             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 167             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 168             sizeof (struct bus_dma_tag), (void **)&newtag);
 169         if (error != 0)
 170                 return (error);
 171
 172         newtag->common.impl = &bus_dma_bounce_impl;
 173         newtag->map_count = 0;
 174         newtag->segments = NULL;
 175
 176         if (parent != NULL && ((newtag->common.filter != NULL) ||
 177             ((parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0)))
 178                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 179
 180         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 181             newtag->common.alignment > 1)
 182                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 183
 184         if (((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 185             (flags & BUS_DMA_ALLOCNOW) != 0) {
 186                 struct bounce_zone *bz;
 187
 188                 /* Must bounce */
 189                 if ((error = alloc_bounce_zone(newtag)) != 0) {
 190                         free(newtag, M_DEVBUF);
 191                         return (error);
 192                 }
 193                 bz = newtag->bounce_zone;
 194
 195                 if (ptoa(bz->total_bpages) < maxsize) {
 196                         int pages;
 197
 198                         pages = atop(maxsize) - bz->total_bpages;
 199
 200                         /* Add pages to our bounce pool */
 201                         if (alloc_bounce_pages(newtag, pages) < pages)
 202                                 error = ENOMEM;
 203                 }
 204                 /* Performed initial allocation */
 205                 newtag->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 206         } else
 207                 error = 0;
 208
 209         if (error != 0)
 210                 free(newtag, M_DEVBUF);
 211         else
 212                 *dmat = newtag;
 213         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 214             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 215             error);
 216         return (error);
 217 }
 218
 219 static int
 220 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 221 {
 222         bus_dma_tag_t dmat_copy, parent;
 223         int error;
 224
 225         error = 0;
 226         dmat_copy = dmat;
 227
 228         if (dmat != NULL) {
 229                 if (dmat->map_count != 0) {
 230                         error = EBUSY;
 231                         goto out;
 232                 }
 233                 while (dmat != NULL) {
 234                         parent = (bus_dma_tag_t)dmat->common.parent;
 235                         atomic_subtract_int(&dmat->common.ref_count, 1);
 236                         if (dmat->common.ref_count == 0) {
 237                                 if (dmat->segments != NULL)
 238                                         free(dmat->segments, M_DEVBUF);
 239                                 free(dmat, M_DEVBUF);
 240                                 /*
 241                                  * Last reference count, so
 242                                  * release our reference
 243                                  * count on our parent.
 244                                  */
 245                                 dmat = parent;
 246                         } else
 247                                 dmat = NULL;
 248                 }
 249         }
 250 out:
 251         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 252         return (error);
 253 }
 254
 255 /*
 256  * Allocate a handle for mapping from kva/uva/physical
 257  * address space into bus device space.
 258  */
 259 static int
 260 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 261 {
 262         struct bounce_zone *bz;
 263         int error, maxpages, pages;
 264
 265         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
 266
 267         error = 0;
 268
 269         if (dmat->segments == NULL) {
 270                 dmat->segments = (bus_dma_segment_t *)malloc(
 271                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 272                     M_DEVBUF, M_NOWAIT);
 273                 if (dmat->segments == NULL) {
 274                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 275                             __func__, dmat, ENOMEM);
 276                         return (ENOMEM);
 277                 }
 278         }
 279
 280         /*
 281          * Bouncing might be required if the driver asks for an active
 282          * exclusion region, a data alignment that is stricter than 1, and/or
 283          * an active address boundary.
 284          */
 285         if (dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) {
 286                 /* Must bounce */
 287                 if (dmat->bounce_zone == NULL) {
 288                         if ((error = alloc_bounce_zone(dmat)) != 0)
 289                                 return (error);
 290                 }
 291                 bz = dmat->bounce_zone;
 292
 293                 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 294                     M_NOWAIT | M_ZERO);
 295                 if (*mapp == NULL) {
 296                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 297                             __func__, dmat, ENOMEM);
 298                         return (ENOMEM);
 299                 }
 300
 301                 /* Initialize the new map */
 302                 STAILQ_INIT(&((*mapp)->bpages));
 303
 304                 /*
 305                  * Attempt to add pages to our pool on a per-instance
 306                  * basis up to a sane limit.
 307                  */
 308                 if (dmat->common.alignment > 1)
 309                         maxpages = MAX_BPAGES;
 310                 else
 311                         maxpages = MIN(MAX_BPAGES, Maxmem -
 312                             atop(dmat->common.lowaddr));
 313                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 314                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 315                         pages = MAX(atop(dmat->common.maxsize), 1);
 316                         pages = MIN(maxpages - bz->total_bpages, pages);
 317                         pages = MAX(pages, 1);
 318                         if (alloc_bounce_pages(dmat, pages) < pages)
 319                                 error = ENOMEM;
 320                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 321                             == 0) {
 322                                 if (error == 0) {
 323                                         dmat->bounce_flags |=
 324                                             BUS_DMA_MIN_ALLOC_COMP;
 325                                 }
 326                         } else
 327                                 error = 0;
 328                 }
 329                 bz->map_count++;
 330         } else {
 331                 *mapp = NULL;
 332         }
 333         if (error == 0)
 334                 dmat->map_count++;
 335         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 336             __func__, dmat, dmat->common.flags, error);
 337         return (error);
 338 }
 339
 340 /*
 341  * Destroy a handle for mapping from kva/uva/physical
 342  * address space into bus device space.
 343  */
 344 static int
 345 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 346 {
 347
 348         if (map != NULL && map != &nobounce_dmamap) {
 349                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 350                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 351                             __func__, dmat, EBUSY);
 352                         return (EBUSY);
 353                 }
 354                 if (dmat->bounce_zone)
 355                         dmat->bounce_zone->map_count--;
 356                 free(map, M_DEVBUF);
 357         }
 358         dmat->map_count--;
 359         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 360         return (0);
 361 }
 362
 363
 364 /*
 365  * Allocate a piece of memory that can be efficiently mapped into
 366  * bus device space based on the constraints lited in the dma tag.
 367  * A dmamap to for use with dmamap_load is also allocated.
 368  */
 369 static int
 370 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 371     bus_dmamap_t *mapp)
 372 {
 373         vm_memattr_t attr;
 374         int mflags;
 375
 376         WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s", __func__);
 377
 378         if (flags & BUS_DMA_NOWAIT)
 379                 mflags = M_NOWAIT;
 380         else
 381                 mflags = M_WAITOK;
 382
 383         /* If we succeed, no mapping/bouncing will be required */
 384         *mapp = NULL;
 385
 386         if (dmat->segments == NULL) {
 387                 dmat->segments = (bus_dma_segment_t *)malloc(
 388                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 389                     M_DEVBUF, mflags);
 390                 if (dmat->segments == NULL) {
 391                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 392                             __func__, dmat, dmat->common.flags, ENOMEM);
 393                         return (ENOMEM);
 394                 }
 395         }
 396         if (flags & BUS_DMA_ZERO)
 397                 mflags |= M_ZERO;
 398         if (flags & BUS_DMA_NOCACHE)
 399                 attr = VM_MEMATTR_UNCACHEABLE;
 400         else
 401                 attr = VM_MEMATTR_DEFAULT;
 402
 403         /*
 404          * Allocate the buffer from the malloc(9) allocator if...
 405          *  - It's small enough to fit into a single power of two sized bucket.
 406          *  - The alignment is less than or equal to the maximum size
 407          *  - The low address requirement is fulfilled.
 408          * else allocate non-contiguous pages if...
 409          *  - The page count that could get allocated doesn't exceed
 410          *    nsegments also when the maximum segment size is less
 411          *    than PAGE_SIZE.
 412          *  - The alignment constraint isn't larger than a page boundary.
 413          *  - There are no boundary-crossing constraints.
 414          * else allocate a block of contiguous pages because one or more of the
 415          * constraints is something that only the contig allocator can fulfill.
 416          *
 417          * NOTE: The (dmat->common.alignment <= dmat->maxsize) check
 418          * below is just a quick hack. The exact alignment guarantees
 419          * of malloc(9) need to be nailed down, and the code below
 420          * should be rewritten to take that into account.
 421          *
 422          * In the meantime warn the user if malloc gets it wrong.
 423          */
 424         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 425            (dmat->common.alignment <= dmat->common.maxsize) &&
 426             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 427             attr == VM_MEMATTR_DEFAULT) {
 428                 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
 429         } else if (dmat->common.nsegments >=
 430             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
 431             dmat->common.alignment <= PAGE_SIZE &&
 432             (dmat->common.boundary % PAGE_SIZE) == 0) {
 433                 /* Page-based multi-segment allocations allowed */
 434                 *vaddr = (void *)kmem_alloc_attr(kernel_arena,
 435                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 436                     attr);
 437                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 438         } else {
 439                 *vaddr = (void *)kmem_alloc_contig(kernel_arena,
 440                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 441                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 442                     dmat->common.boundary, attr);
 443                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 444         }
 445         if (*vaddr == NULL) {
 446                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 447                     __func__, dmat, dmat->common.flags, ENOMEM);
 448                 return (ENOMEM);
 449         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 450                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 451         }
 452         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 453             __func__, dmat, dmat->common.flags, 0);
 454         return (0);
 455 }
 456
 457 /*
 458  * Free a piece of memory and it's allociated dmamap, that was allocated
 459  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 460  */
 461 static void
 462 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 463 {
 464         /*
 465          * dmamem does not need to be bounced, so the map should be
 466          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 467          * was used and set if kmem_alloc_contig() was used.
 468          */
 469         if (map != NULL)
 470                 panic("bus_dmamem_free: Invalid map freed\n");
 471         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 472                 free(vaddr, M_DEVBUF);
 473         else
 474                 kmem_free(kernel_arena, (vm_offset_t)vaddr,
 475                     dmat->common.maxsize);
 476         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 477             dmat->bounce_flags);
 478 }
 479
 480 static void
 481 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 482     bus_size_t buflen, int flags)
 483 {
 484         bus_addr_t curaddr;
 485         bus_size_t sgsize;
 486
 487         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 488                 /*
 489                  * Count the number of bounce pages
 490                  * needed in order to complete this transfer
 491                  */
 492                 curaddr = buf;
 493                 while (buflen != 0) {
 494                         sgsize = MIN(buflen, dmat->common.maxsegsz);
 495                         if (bus_dma_run_filter(&dmat->common, curaddr)) {
 496                                 sgsize = MIN(sgsize,
 497                                     PAGE_SIZE - (curaddr & PAGE_MASK));
 498                                 map->pagesneeded++;
 499                         }
 500                         curaddr += sgsize;
 501                         buflen -= sgsize;
 502                 }
 503                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 504         }
 505 }
 506
 507 static void
 508 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 509     void *buf, bus_size_t buflen, int flags)
 510 {
 511         vm_offset_t vaddr;
 512         vm_offset_t vendaddr;
 513         bus_addr_t paddr;
 514         bus_size_t sg_len;
 515
 516         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 517                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 518                     "alignment= %d", dmat->common.lowaddr,
 519                     ptoa((vm_paddr_t)Maxmem),
 520                     dmat->common.boundary, dmat->common.alignment);
 521                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 522                     map, &nobounce_dmamap, map->pagesneeded);
 523                 /*
 524                  * Count the number of bounce pages
 525                  * needed in order to complete this transfer
 526                  */
 527                 vaddr = (vm_offset_t)buf;
 528                 vendaddr = (vm_offset_t)buf + buflen;
 529
 530                 while (vaddr < vendaddr) {
 531                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 532                         if (pmap == kernel_pmap)
 533                                 paddr = pmap_kextract(vaddr);
 534                         else
 535                                 paddr = pmap_extract(pmap, vaddr);
 536                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 537                                 sg_len = roundup2(sg_len,
 538                                     dmat->common.alignment);
 539                                 map->pagesneeded++;
 540                         }
 541                         vaddr += sg_len;
 542                 }
 543                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 544         }
 545 }
 546
 547 static void
 548 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 549     int ma_offs, bus_size_t buflen, int flags)
 550 {
 551         bus_size_t sg_len, max_sgsize;
 552         int page_index;
 553         vm_paddr_t paddr;
 554
 555         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 556                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 557                     "alignment= %d", dmat->common.lowaddr,
 558                     ptoa((vm_paddr_t)Maxmem),
 559                     dmat->common.boundary, dmat->common.alignment);
 560                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 561                     map, &nobounce_dmamap, map->pagesneeded);
 562
 563                 /*
 564                  * Count the number of bounce pages
 565                  * needed in order to complete this transfer
 566                  */
 567                 page_index = 0;
 568                 while (buflen > 0) {
 569                         paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 570                         sg_len = PAGE_SIZE - ma_offs;
 571                         max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 572                         sg_len = MIN(sg_len, max_sgsize);
 573                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 574                                 sg_len = roundup2(sg_len,
 575                                     dmat->common.alignment);
 576                                 sg_len = MIN(sg_len, max_sgsize);
 577                                 KASSERT((sg_len & (dmat->common.alignment - 1))
 578                                     == 0, ("Segment size is not aligned"));
 579                                 map->pagesneeded++;
 580                         }
 581                         if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
 582                                 page_index++;
 583                         ma_offs = (ma_offs + sg_len) & PAGE_MASK;
 584                         KASSERT(buflen >= sg_len,
 585                             ("Segment length overruns original buffer"));
 586                         buflen -= sg_len;
 587                 }
 588                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 589         }
 590 }
 591
 592 static int
 593 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 594 {
 595
 596         /* Reserve Necessary Bounce Pages */
 597         mtx_lock(&bounce_lock);
 598         if (flags & BUS_DMA_NOWAIT) {
 599                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 600                         mtx_unlock(&bounce_lock);
 601                         return (ENOMEM);
 602                 }
 603         } else {
 604                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 605                         /* Queue us for resources */
 606                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 607                         mtx_unlock(&bounce_lock);
 608                         return (EINPROGRESS);
 609                 }
 610         }
 611         mtx_unlock(&bounce_lock);
 612
 613         return (0);
 614 }
 615
 616 /*
 617  * Add a single contiguous physical range to the segment list.
 618  */
 619 static int
 620 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 621     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 622 {
 623         bus_addr_t baddr, bmask;
 624         int seg;
 625
 626         /*
 627          * Make sure we don't cross any boundaries.
 628          */
 629         bmask = ~(dmat->common.boundary - 1);
 630         if (dmat->common.boundary > 0) {
 631                 baddr = (curaddr + dmat->common.boundary) & bmask;
 632                 if (sgsize > (baddr - curaddr))
 633                         sgsize = (baddr - curaddr);
 634         }
 635
 636         /*
 637          * Insert chunk into a segment, coalescing with
 638          * previous segment if possible.
 639          */
 640         seg = *segp;
 641         if (seg == -1) {
 642                 seg = 0;
 643                 segs[seg].ds_addr = curaddr;
 644                 segs[seg].ds_len = sgsize;
 645         } else {
 646                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 647                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 648                     (dmat->common.boundary == 0 ||
 649                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 650                         segs[seg].ds_len += sgsize;
 651                 else {
 652                         if (++seg >= dmat->common.nsegments)
 653                                 return (0);
 654                         segs[seg].ds_addr = curaddr;
 655                         segs[seg].ds_len = sgsize;
 656                 }
 657         }
 658         *segp = seg;
 659         return (sgsize);
 660 }
 661
 662 /*
 663  * Utility function to load a physical buffer.  segp contains
 664  * the starting segment on entrace, and the ending segment on exit.
 665  */
 666 static int
 667 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 668     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 669     int *segp)
 670 {
 671         bus_size_t sgsize;
 672         bus_addr_t curaddr;
 673         int error;
 674
 675         if (map == NULL)
 676                 map = &nobounce_dmamap;
 677
 678         if (segs == NULL)
 679                 segs = dmat->segments;
 680
 681         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 682                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 683                 if (map->pagesneeded != 0) {
 684                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 685                         if (error)
 686                                 return (error);
 687                 }
 688         }
 689
 690         while (buflen > 0) {
 691                 curaddr = buf;
 692                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 693                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 694                     map->pagesneeded != 0 &&
 695                     bus_dma_run_filter(&dmat->common, curaddr)) {
 696                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 697                         curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
 698                             sgsize);
 699                 }
 700                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 701                     segp);
 702                 if (sgsize == 0)
 703                         break;
 704                 buf += sgsize;
 705                 buflen -= sgsize;
 706         }
 707
 708         /*
 709          * Did we fit?
 710          */
 711         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 712 }
 713
 714 /*
 715  * Utility function to load a linear buffer.  segp contains
 716  * the starting segment on entrace, and the ending segment on exit.
 717  */
 718 static int
 719 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 720     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 721     int *segp)
 722 {
 723         bus_size_t sgsize, max_sgsize;
 724         bus_addr_t curaddr;
 725         vm_offset_t kvaddr, vaddr;
 726         int error;
 727
 728         if (map == NULL)
 729                 map = &nobounce_dmamap;
 730
 731         if (segs == NULL)
 732                 segs = dmat->segments;
 733
 734         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 735                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 736                 if (map->pagesneeded != 0) {
 737                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 738                         if (error)
 739                                 return (error);
 740                 }
 741         }
 742
 743         vaddr = (vm_offset_t)buf;
 744         while (buflen > 0) {
 745                 /*
 746                  * Get the physical address for this segment.
 747                  */
 748                 if (pmap == kernel_pmap) {
 749                         curaddr = pmap_kextract(vaddr);
 750                         kvaddr = vaddr;
 751                 } else {
 752                         curaddr = pmap_extract(pmap, vaddr);
 753                         kvaddr = 0;
 754                 }
 755
 756                 /*
 757                  * Compute the segment size, and adjust counts.
 758                  */
 759                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 760                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 761                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 762                     map->pagesneeded != 0 &&
 763                     bus_dma_run_filter(&dmat->common, curaddr)) {
 764                         sgsize = roundup2(sgsize, dmat->common.alignment);
 765                         sgsize = MIN(sgsize, max_sgsize);
 766                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 767                             sgsize);
 768                 } else {
 769                         sgsize = MIN(sgsize, max_sgsize);
 770                 }
 771                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 772                     segp);
 773                 if (sgsize == 0)
 774                         break;
 775                 vaddr += sgsize;
 776                 buflen -= sgsize;
 777         }
 778
 779         /*
 780          * Did we fit?
 781          */
 782         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 783 }
 784
 785 static int
 786 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 787     struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
 788     bus_dma_segment_t *segs, int *segp)
 789 {
 790         vm_paddr_t paddr, next_paddr;
 791         int error, page_index;
 792         bus_size_t sgsize, max_sgsize;
 793
 794         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 795                 /*
 796                  * If we have to keep the offset of each page this function
 797                  * is not suitable, switch back to bus_dmamap_load_ma_triv
 798                  * which is going to do the right thing in this case.
 799                  */
 800                 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
 801                     flags, segs, segp);
 802                 return (error);
 803         }
 804
 805         if (map == NULL)
 806                 map = &nobounce_dmamap;
 807
 808         if (segs == NULL)
 809                 segs = dmat->segments;
 810
 811         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 812                 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
 813                 if (map->pagesneeded != 0) {
 814                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 815                         if (error)
 816                                 return (error);
 817                 }
 818         }
 819
 820         page_index = 0;
 821         while (buflen > 0) {
 822                 /*
 823                  * Compute the segment size, and adjust counts.
 824                  */
 825                 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 826                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 827                 sgsize = PAGE_SIZE - ma_offs;
 828                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 829                     map->pagesneeded != 0 &&
 830                     bus_dma_run_filter(&dmat->common, paddr)) {
 831                         sgsize = roundup2(sgsize, dmat->common.alignment);
 832                         sgsize = MIN(sgsize, max_sgsize);
 833                         KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
 834                             ("Segment size is not aligned"));
 835                         /*
 836                          * Check if two pages of the user provided buffer
 837                          * are used.
 838                          */
 839                         if ((ma_offs + sgsize) > PAGE_SIZE)
 840                                 next_paddr =
 841                                     VM_PAGE_TO_PHYS(ma[page_index + 1]);
 842                         else
 843                                 next_paddr = 0;
 844                         paddr = add_bounce_page(dmat, map, 0, paddr,
 845                             next_paddr, sgsize);
 846                 } else {
 847                         sgsize = MIN(sgsize, max_sgsize);
 848                 }
 849                 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
 850                     segp);
 851                 if (sgsize == 0)
 852                         break;
 853                 KASSERT(buflen >= sgsize,
 854                     ("Segment length overruns original buffer"));
 855                 buflen -= sgsize;
 856                 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
 857                         page_index++;
 858                 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
 859         }
 860
 861         /*
 862          * Did we fit?
 863          */
 864         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 865 }
 866
 867 static void
 868 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 869     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 870 {
 871
 872         if (map == NULL)
 873                 return;
 874         map->mem = *mem;
 875         map->dmat = dmat;
 876         map->callback = callback;
 877         map->callback_arg = callback_arg;
 878 }
 879
 880 static bus_dma_segment_t *
 881 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 882     bus_dma_segment_t *segs, int nsegs, int error)
 883 {
 884
 885         if (segs == NULL)
 886                 segs = dmat->segments;
 887         return (segs);
 888 }
 889
 890 /*
 891  * Release the mapping held by map.
 892  */
 893 static void
 894 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 895 {
 896         struct bounce_page *bpage;
 897
 898         if (map == NULL)
 899                 return;
 900
 901         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 902                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 903                 free_bounce_page(dmat, bpage);
 904         }
 905 }
 906
 907 static void
 908 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 909     bus_dmasync_op_t op)
 910 {
 911         struct bounce_page *bpage;
 912         vm_offset_t datavaddr, tempvaddr;
 913         bus_size_t datacount1, datacount2;
 914
 915         if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 916                 return;
 917
 918         /*
 919          * Handle data bouncing.  We might also want to add support for
 920          * invalidating the caches on broken hardware.
 921          */
 922         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 923             "performing bounce", __func__, dmat, dmat->common.flags, op);
 924
 925         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 926                 while (bpage != NULL) {
 927                         tempvaddr = 0;
 928                         datavaddr = bpage->datavaddr;
 929                         datacount1 = bpage->datacount;
 930                         if (datavaddr == 0) {
 931                                 tempvaddr =
 932                                     pmap_quick_enter_page(bpage->datapage[0]);
 933                                 datavaddr = tempvaddr | bpage->dataoffs;
 934                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 935                                     datacount1);
 936                         }
 937
 938                         bcopy((void *)datavaddr,
 939                             (void *)bpage->vaddr, datacount1);
 940
 941                         if (tempvaddr != 0)
 942                                 pmap_quick_remove_page(tempvaddr);
 943
 944                         if (bpage->datapage[1] == 0) {
 945                                 KASSERT(datacount1 == bpage->datacount,
 946                 ("Mismatch between data size and provided memory space"));
 947                                 goto next_w;
 948                         }
 949
 950                         /*
 951                          * We are dealing with an unmapped buffer that expands
 952                          * over two pages.
 953                          */
 954                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
 955                         datacount2 = bpage->datacount - datacount1;
 956                         bcopy((void *)datavaddr,
 957                             (void *)(bpage->vaddr + datacount1), datacount2);
 958                         pmap_quick_remove_page(datavaddr);
 959
 960 next_w:
 961                         bpage = STAILQ_NEXT(bpage, links);
 962                 }
 963                 dmat->bounce_zone->total_bounced++;
 964         }
 965
 966         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
 967                 while (bpage != NULL) {
 968                         tempvaddr = 0;
 969                         datavaddr = bpage->datavaddr;
 970                         datacount1 = bpage->datacount;
 971                         if (datavaddr == 0) {
 972                                 tempvaddr =
 973                                     pmap_quick_enter_page(bpage->datapage[0]);
 974                                 datavaddr = tempvaddr | bpage->dataoffs;
 975                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 976                                     datacount1);
 977                         }
 978
 979                         bcopy((void *)bpage->vaddr, (void *)datavaddr,
 980                             datacount1);
 981
 982                         if (tempvaddr != 0)
 983                                 pmap_quick_remove_page(tempvaddr);
 984
 985                         if (bpage->datapage[1] == 0) {
 986                                 KASSERT(datacount1 == bpage->datacount,
 987                 ("Mismatch between data size and provided memory space"));
 988                                 goto next_r;
 989                         }
 990
 991                         /*
 992                          * We are dealing with an unmapped buffer that expands
 993                          * over two pages.
 994                          */
 995                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
 996                         datacount2 = bpage->datacount - datacount1;
 997                         bcopy((void *)(bpage->vaddr + datacount1),
 998                             (void *)datavaddr, datacount2);
 999                         pmap_quick_remove_page(datavaddr);
1000
1001 next_r:
1002                         bpage = STAILQ_NEXT(bpage, links);
1003                 }
1004                 dmat->bounce_zone->total_bounced++;
1005         }
1006 }
1007
1008 static void
1009 init_bounce_pages(void *dummy __unused)
1010 {
1011
1012         total_bpages = 0;
1013         STAILQ_INIT(&bounce_zone_list);
1014         STAILQ_INIT(&bounce_map_waitinglist);
1015         STAILQ_INIT(&bounce_map_callbacklist);
1016         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1017 }
1018 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1019
1020 static struct sysctl_ctx_list *
1021 busdma_sysctl_tree(struct bounce_zone *bz)
1022 {
1023
1024         return (&bz->sysctl_tree);
1025 }
1026
1027 static struct sysctl_oid *
1028 busdma_sysctl_tree_top(struct bounce_zone *bz)
1029 {
1030
1031         return (bz->sysctl_tree_top);
1032 }
1033
1034 static int
1035 alloc_bounce_zone(bus_dma_tag_t dmat)
1036 {
1037         struct bounce_zone *bz;
1038
1039         /* Check to see if we already have a suitable zone */
1040         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1041                 if ((dmat->common.alignment <= bz->alignment) &&
1042                     (dmat->common.lowaddr >= bz->lowaddr)) {
1043                         dmat->bounce_zone = bz;
1044                         return (0);
1045                 }
1046         }
1047
1048         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1049             M_NOWAIT | M_ZERO)) == NULL)
1050                 return (ENOMEM);
1051
1052         STAILQ_INIT(&bz->bounce_page_list);
1053         bz->free_bpages = 0;
1054         bz->reserved_bpages = 0;
1055         bz->active_bpages = 0;
1056         bz->lowaddr = dmat->common.lowaddr;
1057         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1058         bz->map_count = 0;
1059         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1060         busdma_zonecount++;
1061         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1062         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1063         dmat->bounce_zone = bz;
1064
1065         sysctl_ctx_init(&bz->sysctl_tree);
1066         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1067             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1068             CTLFLAG_RD, 0, "");
1069         if (bz->sysctl_tree_top == NULL) {
1070                 sysctl_ctx_free(&bz->sysctl_tree);
1071                 return (0);     /* XXX error code? */
1072         }
1073
1074         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1075             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1076             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1077             "Total bounce pages");
1078         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1079             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1080             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1081             "Free bounce pages");
1082         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1083             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1084             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1085             "Reserved bounce pages");
1086         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1087             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1088             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1089             "Active bounce pages");
1090         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1091             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1092             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1093             "Total bounce requests");
1094         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1095             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1096             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1097             "Total bounce requests that were deferred");
1098         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1099             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1100             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1101         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1102             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1103             "alignment", CTLFLAG_RD, &bz->alignment, "");
1104
1105         return (0);
1106 }
1107
1108 static int
1109 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1110 {
1111         struct bounce_zone *bz;
1112         int count;
1113
1114         bz = dmat->bounce_zone;
1115         count = 0;
1116         while (numpages > 0) {
1117                 struct bounce_page *bpage;
1118
1119                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1120                                                      M_NOWAIT | M_ZERO);
1121
1122                 if (bpage == NULL)
1123                         break;
1124                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1125                                                          M_NOWAIT, 0ul,
1126                                                          bz->lowaddr,
1127                                                          PAGE_SIZE,
1128                                                          0);
1129                 if (bpage->vaddr == 0) {
1130                         free(bpage, M_DEVBUF);
1131                         break;
1132                 }
1133                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1134                 mtx_lock(&bounce_lock);
1135                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1136                 total_bpages++;
1137                 bz->total_bpages++;
1138                 bz->free_bpages++;
1139                 mtx_unlock(&bounce_lock);
1140                 count++;
1141                 numpages--;
1142         }
1143         return (count);
1144 }
1145
1146 static int
1147 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1148 {
1149         struct bounce_zone *bz;
1150         int pages;
1151
1152         mtx_assert(&bounce_lock, MA_OWNED);
1153         bz = dmat->bounce_zone;
1154         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1155         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1156                 return (map->pagesneeded - (map->pagesreserved + pages));
1157         bz->free_bpages -= pages;
1158         bz->reserved_bpages += pages;
1159         map->pagesreserved += pages;
1160         pages = map->pagesneeded - map->pagesreserved;
1161
1162         return (pages);
1163 }
1164
1165 static bus_addr_t
1166 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1167                 bus_addr_t addr1, bus_addr_t addr2, bus_size_t size)
1168 {
1169         struct bounce_zone *bz;
1170         struct bounce_page *bpage;
1171
1172         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1173         KASSERT(map != NULL && map != &nobounce_dmamap,
1174             ("add_bounce_page: bad map %p", map));
1175
1176         bz = dmat->bounce_zone;
1177         if (map->pagesneeded == 0)
1178                 panic("add_bounce_page: map doesn't need any pages");
1179         map->pagesneeded--;
1180
1181         if (map->pagesreserved == 0)
1182                 panic("add_bounce_page: map doesn't need any pages");
1183         map->pagesreserved--;
1184
1185         mtx_lock(&bounce_lock);
1186         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1187         if (bpage == NULL)
1188                 panic("add_bounce_page: free page list is empty");
1189
1190         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1191         bz->reserved_bpages--;
1192         bz->active_bpages++;
1193         mtx_unlock(&bounce_lock);
1194
1195         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1196                 /* Page offset needs to be preserved. */
1197                 bpage->vaddr |= addr1 & PAGE_MASK;
1198                 bpage->busaddr |= addr1 & PAGE_MASK;
1199                 KASSERT(addr2 == 0,
1200         ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1201         }
1202         bpage->datavaddr = vaddr;
1203         bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1204         KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1205         bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1206         bpage->dataoffs = addr1 & PAGE_MASK;
1207         bpage->datacount = size;
1208         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1209         return (bpage->busaddr);
1210 }
1211
1212 static void
1213 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1214 {
1215         struct bus_dmamap *map;
1216         struct bounce_zone *bz;
1217
1218         bz = dmat->bounce_zone;
1219         bpage->datavaddr = 0;
1220         bpage->datacount = 0;
1221         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1222                 /*
1223                  * Reset the bounce page to start at offset 0.  Other uses
1224                  * of this bounce page may need to store a full page of
1225                  * data and/or assume it starts on a page boundary.
1226                  */
1227                 bpage->vaddr &= ~PAGE_MASK;
1228                 bpage->busaddr &= ~PAGE_MASK;
1229         }
1230
1231         mtx_lock(&bounce_lock);
1232         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1233         bz->free_bpages++;
1234         bz->active_bpages--;
1235         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1236                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1237                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1238                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1239                             map, links);
1240                         busdma_swi_pending = 1;
1241                         bz->total_deferred++;
1242                         swi_sched(vm_ih, 0);
1243                 }
1244         }
1245         mtx_unlock(&bounce_lock);
1246 }
1247
1248 void
1249 busdma_swi(void)
1250 {
1251         bus_dma_tag_t dmat;
1252         struct bus_dmamap *map;
1253
1254         mtx_lock(&bounce_lock);
1255         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1256                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1257                 mtx_unlock(&bounce_lock);
1258                 dmat = map->dmat;
1259                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1260                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1261                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1262                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1263                     BUS_DMA_UNLOCK);
1264                 mtx_lock(&bounce_lock);
1265         }
1266         mtx_unlock(&bounce_lock);
1267 }
1268
1269 struct bus_dma_impl bus_dma_bounce_impl = {
1270         .tag_create = bounce_bus_dma_tag_create,
1271         .tag_destroy = bounce_bus_dma_tag_destroy,
1272         .map_create = bounce_bus_dmamap_create,
1273         .map_destroy = bounce_bus_dmamap_destroy,
1274         .mem_alloc = bounce_bus_dmamem_alloc,
1275         .mem_free = bounce_bus_dmamem_free,
1276         .load_phys = bounce_bus_dmamap_load_phys,
1277         .load_buffer = bounce_bus_dmamap_load_buffer,
1278         .load_ma = bounce_bus_dmamap_load_ma,
1279         .map_waitok = bounce_bus_dmamap_waitok,
1280         .map_complete = bounce_bus_dmamap_complete,
1281         .map_unload = bounce_bus_dmamap_unload,
1282         .map_sync = bounce_bus_dmamap_sync
1283 };