sys/x86/x86/busdma_bounce.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1997, 1998 Justin T. Gibbs.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions, and the following disclaimer,
  12  *    without modification, immediately at the beginning of the file.
  13  * 2. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/systm.h>
  34 #include <sys/domainset.h>
  35 #include <sys/malloc.h>
  36 #include <sys/bus.h>
  37 #include <sys/interrupt.h>
  38 #include <sys/kernel.h>
  39 #include <sys/ktr.h>
  40 #include <sys/lock.h>
  41 #include <sys/proc.h>
  42 #include <sys/memdesc.h>
  43 #include <sys/mutex.h>
  44 #include <sys/sysctl.h>
  45 #include <sys/uio.h>
  46
  47 #include <vm/vm.h>
  48 #include <vm/vm_extern.h>
  49 #include <vm/vm_kern.h>
  50 #include <vm/vm_page.h>
  51 #include <vm/vm_map.h>
  52
  53 #include <machine/atomic.h>
  54 #include <machine/bus.h>
  55 #include <machine/md_var.h>
  56 #include <machine/specialreg.h>
  57 #include <x86/include/busdma_impl.h>
  58
  59 #ifdef __i386__
  60 #define MAX_BPAGES (Maxmem > atop(0x100000000ULL) ? 8192 : 512)
  61 #else
  62 #define MAX_BPAGES 8192
  63 #endif
  64
  65 enum {
  66         BUS_DMA_COULD_BOUNCE    = 0x01,
  67         BUS_DMA_MIN_ALLOC_COMP  = 0x02,
  68         BUS_DMA_KMEM_ALLOC      = 0x04,
  69 };
  70
  71 struct bounce_zone;
  72
  73 struct bus_dma_tag {
  74         struct bus_dma_tag_common common;
  75         int                     map_count;
  76         int                     bounce_flags;
  77         bus_dma_segment_t       *segments;
  78         struct bounce_zone      *bounce_zone;
  79 };
  80
  81 struct bounce_page {
  82         vm_offset_t     vaddr;          /* kva of bounce buffer */
  83         bus_addr_t      busaddr;        /* Physical address */
  84         vm_offset_t     datavaddr;      /* kva of client data */
  85         vm_offset_t     dataoffs;       /* page offset of client data */
  86         vm_page_t       datapage[2];    /* physical page(s) of client data */
  87         bus_size_t      datacount;      /* client data count */
  88         STAILQ_ENTRY(bounce_page) links;
  89 };
  90
  91 struct bounce_zone {
  92         STAILQ_ENTRY(bounce_zone) links;
  93         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  94         int             total_bpages;
  95         int             free_bpages;
  96         int             reserved_bpages;
  97         int             active_bpages;
  98         int             total_bounced;
  99         int             total_deferred;
 100         int             map_count;
 101         int             domain;
 102         bus_size_t      alignment;
 103         bus_addr_t      lowaddr;
 104         char            zoneid[8];
 105         char            lowaddrid[20];
 106         struct sysctl_ctx_list sysctl_tree;
 107         struct sysctl_oid *sysctl_tree_top;
 108 };
 109
 110 static struct mtx bounce_lock;
 111 static int total_bpages;
 112 static int busdma_zonecount;
 113 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
 114 static void *busdma_ih;
 115
 116 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
 117     "Busdma parameters");
 118 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 119            "Total bounce pages");
 120
 121 struct bus_dmamap {
 122         struct bp_list         bpages;
 123         int                    pagesneeded;
 124         int                    pagesreserved;
 125         bus_dma_tag_t          dmat;
 126         struct memdesc         mem;
 127         bus_dmamap_callback_t *callback;
 128         void                  *callback_arg;
 129         STAILQ_ENTRY(bus_dmamap) links;
 130 };
 131
 132 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 133 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 134 static struct bus_dmamap nobounce_dmamap;
 135
 136 static void init_bounce_pages(void *dummy);
 137 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 138 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 139 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 140     int commit);
 141 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 142     vm_offset_t vaddr, vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size);
 143 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 144 static bool _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf,
 145     bus_size_t buflen, int *pagesneeded);
 146 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 147     pmap_t pmap, void *buf, bus_size_t buflen, int flags);
 148 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 149     vm_paddr_t buf, bus_size_t buflen, int flags);
 150 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 151     int flags);
 152
 153 static int
 154 bounce_bus_dma_zone_setup(bus_dma_tag_t dmat)
 155 {
 156         struct bounce_zone *bz;
 157         int error;
 158
 159         /* Must bounce */
 160         if ((error = alloc_bounce_zone(dmat)) != 0)
 161                 return (error);
 162         bz = dmat->bounce_zone;
 163
 164         if (ptoa(bz->total_bpages) < dmat->common.maxsize) {
 165                 int pages;
 166
 167                 pages = atop(dmat->common.maxsize) - bz->total_bpages;
 168
 169                 /* Add pages to our bounce pool */
 170                 if (alloc_bounce_pages(dmat, pages) < pages)
 171                         return (ENOMEM);
 172         }
 173         /* Performed initial allocation */
 174         dmat->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 175
 176         return (0);
 177 }
 178
 179 /*
 180  * Allocate a device specific dma_tag.
 181  */
 182 static int
 183 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 184     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 185     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 186     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 187     void *lockfuncarg, bus_dma_tag_t *dmat)
 188 {
 189         bus_dma_tag_t newtag;
 190         int error;
 191
 192         *dmat = NULL;
 193         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 194             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 195             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 196             sizeof (struct bus_dma_tag), (void **)&newtag);
 197         if (error != 0)
 198                 return (error);
 199
 200         newtag->common.impl = &bus_dma_bounce_impl;
 201         newtag->map_count = 0;
 202         newtag->segments = NULL;
 203
 204         if (parent != NULL && (newtag->common.filter != NULL ||
 205             (parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0))
 206                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 207
 208         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 209             newtag->common.alignment > 1)
 210                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 211
 212         if ((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 213             (flags & BUS_DMA_ALLOCNOW) != 0)
 214                 error = bounce_bus_dma_zone_setup(newtag);
 215         else
 216                 error = 0;
 217
 218         if (error != 0)
 219                 free(newtag, M_DEVBUF);
 220         else
 221                 *dmat = newtag;
 222         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 223             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 224             error);
 225         return (error);
 226 }
 227
 228 static bool
 229 bounce_bus_dma_id_mapped(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen)
 230 {
 231
 232         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0)
 233                 return (true);
 234         return (!_bus_dmamap_pagesneeded(dmat, buf, buflen, NULL));
 235 }
 236
 237 /*
 238  * Update the domain for the tag.  We may need to reallocate the zone and
 239  * bounce pages.
 240  */
 241 static int
 242 bounce_bus_dma_tag_set_domain(bus_dma_tag_t dmat)
 243 {
 244
 245         KASSERT(dmat->map_count == 0,
 246             ("bounce_bus_dma_tag_set_domain:  Domain set after use.\n"));
 247         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) == 0 ||
 248             dmat->bounce_zone == NULL)
 249                 return (0);
 250         dmat->bounce_flags &= ~BUS_DMA_MIN_ALLOC_COMP;
 251         return (bounce_bus_dma_zone_setup(dmat));
 252 }
 253
 254 static int
 255 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 256 {
 257         bus_dma_tag_t dmat_copy, parent;
 258         int error;
 259
 260         error = 0;
 261         dmat_copy = dmat;
 262
 263         if (dmat != NULL) {
 264                 if (dmat->map_count != 0) {
 265                         error = EBUSY;
 266                         goto out;
 267                 }
 268                 while (dmat != NULL) {
 269                         parent = (bus_dma_tag_t)dmat->common.parent;
 270                         atomic_subtract_int(&dmat->common.ref_count, 1);
 271                         if (dmat->common.ref_count == 0) {
 272                                 if (dmat->segments != NULL)
 273                                         free(dmat->segments, M_DEVBUF);
 274                                 free(dmat, M_DEVBUF);
 275                                 /*
 276                                  * Last reference count, so
 277                                  * release our reference
 278                                  * count on our parent.
 279                                  */
 280                                 dmat = parent;
 281                         } else
 282                                 dmat = NULL;
 283                 }
 284         }
 285 out:
 286         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 287         return (error);
 288 }
 289
 290 /*
 291  * Allocate a handle for mapping from kva/uva/physical
 292  * address space into bus device space.
 293  */
 294 static int
 295 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 296 {
 297         struct bounce_zone *bz;
 298         int error, maxpages, pages;
 299
 300         error = 0;
 301
 302         if (dmat->segments == NULL) {
 303                 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
 304                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 305                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT);
 306                 if (dmat->segments == NULL) {
 307                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 308                             __func__, dmat, ENOMEM);
 309                         return (ENOMEM);
 310                 }
 311         }
 312
 313         /*
 314          * Bouncing might be required if the driver asks for an active
 315          * exclusion region, a data alignment that is stricter than 1, and/or
 316          * an active address boundary.
 317          */
 318         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 319                 /* Must bounce */
 320                 if (dmat->bounce_zone == NULL) {
 321                         if ((error = alloc_bounce_zone(dmat)) != 0)
 322                                 return (error);
 323                 }
 324                 bz = dmat->bounce_zone;
 325
 326                 *mapp = (bus_dmamap_t)malloc_domainset(sizeof(**mapp), M_DEVBUF,
 327                     DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
 328                 if (*mapp == NULL) {
 329                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 330                             __func__, dmat, ENOMEM);
 331                         return (ENOMEM);
 332                 }
 333
 334                 /* Initialize the new map */
 335                 STAILQ_INIT(&((*mapp)->bpages));
 336
 337                 /*
 338                  * Attempt to add pages to our pool on a per-instance
 339                  * basis up to a sane limit.
 340                  */
 341                 if (dmat->common.alignment > 1)
 342                         maxpages = MAX_BPAGES;
 343                 else
 344                         maxpages = MIN(MAX_BPAGES, Maxmem -
 345                             atop(dmat->common.lowaddr));
 346                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 347                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 348                         pages = MAX(atop(dmat->common.maxsize), 1);
 349                         pages = MIN(maxpages - bz->total_bpages, pages);
 350                         pages = MAX(pages, 1);
 351                         if (alloc_bounce_pages(dmat, pages) < pages)
 352                                 error = ENOMEM;
 353                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 354                             == 0) {
 355                                 if (error == 0) {
 356                                         dmat->bounce_flags |=
 357                                             BUS_DMA_MIN_ALLOC_COMP;
 358                                 }
 359                         } else
 360                                 error = 0;
 361                 }
 362                 bz->map_count++;
 363         } else {
 364                 *mapp = NULL;
 365         }
 366         if (error == 0)
 367                 dmat->map_count++;
 368         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 369             __func__, dmat, dmat->common.flags, error);
 370         return (error);
 371 }
 372
 373 /*
 374  * Destroy a handle for mapping from kva/uva/physical
 375  * address space into bus device space.
 376  */
 377 static int
 378 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 379 {
 380
 381         if (map != NULL && map != &nobounce_dmamap) {
 382                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 383                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 384                             __func__, dmat, EBUSY);
 385                         return (EBUSY);
 386                 }
 387                 if (dmat->bounce_zone)
 388                         dmat->bounce_zone->map_count--;
 389                 free(map, M_DEVBUF);
 390         }
 391         dmat->map_count--;
 392         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 393         return (0);
 394 }
 395
 396 /*
 397  * Allocate a piece of memory that can be efficiently mapped into
 398  * bus device space based on the constraints lited in the dma tag.
 399  * A dmamap to for use with dmamap_load is also allocated.
 400  */
 401 static int
 402 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
 403     bus_dmamap_t *mapp)
 404 {
 405         vm_memattr_t attr;
 406         int mflags;
 407
 408         if (flags & BUS_DMA_NOWAIT)
 409                 mflags = M_NOWAIT;
 410         else
 411                 mflags = M_WAITOK;
 412
 413         /* If we succeed, no mapping/bouncing will be required */
 414         *mapp = NULL;
 415
 416         if (dmat->segments == NULL) {
 417                 dmat->segments = (bus_dma_segment_t *)malloc_domainset(
 418                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 419                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), mflags);
 420                 if (dmat->segments == NULL) {
 421                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 422                             __func__, dmat, dmat->common.flags, ENOMEM);
 423                         return (ENOMEM);
 424                 }
 425         }
 426         if (flags & BUS_DMA_ZERO)
 427                 mflags |= M_ZERO;
 428         if (flags & BUS_DMA_NOCACHE)
 429                 attr = VM_MEMATTR_UNCACHEABLE;
 430         else
 431                 attr = VM_MEMATTR_DEFAULT;
 432
 433         /*
 434          * Allocate the buffer from the malloc(9) allocator if...
 435          *  - It's small enough to fit into a single page.
 436          *  - Its alignment requirement is also smaller than the page size.
 437          *  - The low address requirement is fulfilled.
 438          *  - Default cache attributes are requested (WB).
 439          * else allocate non-contiguous pages if...
 440          *  - The page count that could get allocated doesn't exceed
 441          *    nsegments also when the maximum segment size is less
 442          *    than PAGE_SIZE.
 443          *  - The alignment constraint isn't larger than a page boundary.
 444          *  - There are no boundary-crossing constraints.
 445          * else allocate a block of contiguous pages because one or more of the
 446          * constraints is something that only the contig allocator can fulfill.
 447          *
 448          * Warn the user if malloc gets it wrong.
 449          */
 450         if (dmat->common.maxsize <= PAGE_SIZE &&
 451             dmat->common.alignment <= PAGE_SIZE &&
 452             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 453             attr == VM_MEMATTR_DEFAULT) {
 454                 *vaddr = malloc_domainset_aligned(dmat->common.maxsize,
 455                     dmat->common.alignment, M_DEVBUF,
 456                     DOMAINSET_PREF(dmat->common.domain), mflags);
 457                 KASSERT(*vaddr == NULL || ((uintptr_t)*vaddr & PAGE_MASK) +
 458                     dmat->common.maxsize <= PAGE_SIZE,
 459                     ("bounce_bus_dmamem_alloc: multi-page alloc %p maxsize "
 460                     "%#jx align %#jx", *vaddr, (uintmax_t)dmat->common.maxsize,
 461                     (uintmax_t)dmat->common.alignment));
 462         } else if (dmat->common.nsegments >=
 463             howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz,
 464             PAGE_SIZE)) &&
 465             dmat->common.alignment <= PAGE_SIZE &&
 466             (dmat->common.boundary % PAGE_SIZE) == 0) {
 467                 /* Page-based multi-segment allocations allowed */
 468                 *vaddr = (void *)kmem_alloc_attr_domainset(
 469                     DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
 470                     mflags, 0ul, dmat->common.lowaddr, attr);
 471                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 472         } else {
 473                 *vaddr = (void *)kmem_alloc_contig_domainset(
 474                     DOMAINSET_PREF(dmat->common.domain), dmat->common.maxsize,
 475                     mflags, 0ul, dmat->common.lowaddr,
 476                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 477                     dmat->common.boundary, attr);
 478                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 479         }
 480         if (*vaddr == NULL) {
 481                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 482                     __func__, dmat, dmat->common.flags, ENOMEM);
 483                 return (ENOMEM);
 484         } else if (!vm_addr_align_ok(vtophys(*vaddr), dmat->common.alignment)) {
 485                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 486         }
 487         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 488             __func__, dmat, dmat->common.flags, 0);
 489         return (0);
 490 }
 491
 492 /*
 493  * Free a piece of memory and its associated dmamap, that was allocated
 494  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 495  */
 496 static void
 497 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 498 {
 499         /*
 500          * dmamem does not need to be bounced, so the map should be
 501          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 502          * was used and set if kmem_alloc_contig() was used.
 503          */
 504         if (map != NULL)
 505                 panic("bus_dmamem_free: Invalid map freed\n");
 506         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 507                 free(vaddr, M_DEVBUF);
 508         else
 509                 kmem_free((vm_offset_t)vaddr, dmat->common.maxsize);
 510         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 511             dmat->bounce_flags);
 512 }
 513
 514 static bool
 515 _bus_dmamap_pagesneeded(bus_dma_tag_t dmat, vm_paddr_t buf, bus_size_t buflen,
 516     int *pagesneeded)
 517 {
 518         vm_paddr_t curaddr;
 519         bus_size_t sgsize;
 520         int count;
 521
 522         /*
 523          * Count the number of bounce pages needed in order to
 524          * complete this transfer
 525          */
 526         count = 0;
 527         curaddr = buf;
 528         while (buflen != 0) {
 529                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 530                 if (bus_dma_run_filter(&dmat->common, curaddr)) {
 531                         sgsize = MIN(sgsize,
 532                             PAGE_SIZE - (curaddr & PAGE_MASK));
 533                         if (pagesneeded == NULL)
 534                                 return (true);
 535                         count++;
 536                 }
 537                 curaddr += sgsize;
 538                 buflen -= sgsize;
 539         }
 540
 541         if (pagesneeded != NULL)
 542                 *pagesneeded = count;
 543         return (count != 0);
 544 }
 545
 546 static void
 547 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 548     bus_size_t buflen, int flags)
 549 {
 550
 551         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 552                 _bus_dmamap_pagesneeded(dmat, buf, buflen, &map->pagesneeded);
 553                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 554         }
 555 }
 556
 557 static void
 558 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 559     void *buf, bus_size_t buflen, int flags)
 560 {
 561         vm_offset_t vaddr;
 562         vm_offset_t vendaddr;
 563         vm_paddr_t paddr;
 564         bus_size_t sg_len;
 565
 566         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 567                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 568                     "alignment= %d", dmat->common.lowaddr,
 569                     ptoa((vm_paddr_t)Maxmem),
 570                     dmat->common.boundary, dmat->common.alignment);
 571                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 572                     map, &nobounce_dmamap, map->pagesneeded);
 573                 /*
 574                  * Count the number of bounce pages
 575                  * needed in order to complete this transfer
 576                  */
 577                 vaddr = (vm_offset_t)buf;
 578                 vendaddr = (vm_offset_t)buf + buflen;
 579
 580                 while (vaddr < vendaddr) {
 581                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 582                         if (pmap == kernel_pmap)
 583                                 paddr = pmap_kextract(vaddr);
 584                         else
 585                                 paddr = pmap_extract(pmap, vaddr);
 586                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 587                                 sg_len = roundup2(sg_len,
 588                                     dmat->common.alignment);
 589                                 map->pagesneeded++;
 590                         }
 591                         vaddr += sg_len;
 592                 }
 593                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 594         }
 595 }
 596
 597 static void
 598 _bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
 599     int ma_offs, bus_size_t buflen, int flags)
 600 {
 601         bus_size_t sg_len, max_sgsize;
 602         int page_index;
 603         vm_paddr_t paddr;
 604
 605         if (map != &nobounce_dmamap && map->pagesneeded == 0) {
 606                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 607                     "alignment= %d", dmat->common.lowaddr,
 608                     ptoa((vm_paddr_t)Maxmem),
 609                     dmat->common.boundary, dmat->common.alignment);
 610                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 611                     map, &nobounce_dmamap, map->pagesneeded);
 612
 613                 /*
 614                  * Count the number of bounce pages
 615                  * needed in order to complete this transfer
 616                  */
 617                 page_index = 0;
 618                 while (buflen > 0) {
 619                         paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 620                         sg_len = PAGE_SIZE - ma_offs;
 621                         max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 622                         sg_len = MIN(sg_len, max_sgsize);
 623                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 624                                 sg_len = roundup2(sg_len,
 625                                     dmat->common.alignment);
 626                                 sg_len = MIN(sg_len, max_sgsize);
 627                                 KASSERT(vm_addr_align_ok(sg_len,
 628                                     dmat->common.alignment),
 629                                     ("Segment size is not aligned"));
 630                                 map->pagesneeded++;
 631                         }
 632                         if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
 633                                 page_index++;
 634                         ma_offs = (ma_offs + sg_len) & PAGE_MASK;
 635                         KASSERT(buflen >= sg_len,
 636                             ("Segment length overruns original buffer"));
 637                         buflen -= sg_len;
 638                 }
 639                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 640         }
 641 }
 642
 643 static int
 644 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 645 {
 646
 647         /* Reserve Necessary Bounce Pages */
 648         mtx_lock(&bounce_lock);
 649         if (flags & BUS_DMA_NOWAIT) {
 650                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 651                         mtx_unlock(&bounce_lock);
 652                         return (ENOMEM);
 653                 }
 654         } else {
 655                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 656                         /* Queue us for resources */
 657                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 658                         mtx_unlock(&bounce_lock);
 659                         return (EINPROGRESS);
 660                 }
 661         }
 662         mtx_unlock(&bounce_lock);
 663
 664         return (0);
 665 }
 666
 667 /*
 668  * Add a single contiguous physical range to the segment list.
 669  */
 670 static bus_size_t
 671 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t curaddr,
 672     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 673 {
 674         int seg;
 675
 676         KASSERT(curaddr <= BUS_SPACE_MAXADDR,
 677             ("ds_addr %#jx > BUS_SPACE_MAXADDR %#jx; dmat %p fl %#x low %#jx "
 678             "hi %#jx",
 679             (uintmax_t)curaddr, (uintmax_t)BUS_SPACE_MAXADDR,
 680             dmat, dmat->bounce_flags, (uintmax_t)dmat->common.lowaddr,
 681             (uintmax_t)dmat->common.highaddr));
 682
 683         /*
 684          * Make sure we don't cross any boundaries.
 685          */
 686         if (!vm_addr_bound_ok(curaddr, sgsize, dmat->common.boundary))
 687                 sgsize = roundup2(curaddr, dmat->common.boundary) - curaddr;
 688
 689         /*
 690          * Insert chunk into a segment, coalescing with
 691          * previous segment if possible.
 692          */
 693         seg = *segp;
 694         if (seg == -1) {
 695                 seg = 0;
 696                 segs[seg].ds_addr = curaddr;
 697                 segs[seg].ds_len = sgsize;
 698         } else {
 699                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 700                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 701                     vm_addr_bound_ok(segs[seg].ds_addr,
 702                     segs[seg].ds_len + sgsize, dmat->common.boundary))
 703                         segs[seg].ds_len += sgsize;
 704                 else {
 705                         if (++seg >= dmat->common.nsegments)
 706                                 return (0);
 707                         segs[seg].ds_addr = curaddr;
 708                         segs[seg].ds_len = sgsize;
 709                 }
 710         }
 711         *segp = seg;
 712         return (sgsize);
 713 }
 714
 715 /*
 716  * Utility function to load a physical buffer.  segp contains
 717  * the starting segment on entrace, and the ending segment on exit.
 718  */
 719 static int
 720 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 721     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 722     int *segp)
 723 {
 724         bus_size_t sgsize;
 725         vm_paddr_t curaddr;
 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_phys(dmat, map, 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         while (buflen > 0) {
 744                 curaddr = buf;
 745                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 746                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 747                     map->pagesneeded != 0 &&
 748                     bus_dma_run_filter(&dmat->common, curaddr)) {
 749                         sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
 750                         curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
 751                             sgsize);
 752                 }
 753                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 754                     segp);
 755                 if (sgsize == 0)
 756                         break;
 757                 buf += sgsize;
 758                 buflen -= sgsize;
 759         }
 760
 761         /*
 762          * Did we fit?
 763          */
 764         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 765 }
 766
 767 /*
 768  * Utility function to load a linear buffer.  segp contains
 769  * the starting segment on entrace, and the ending segment on exit.
 770  */
 771 static int
 772 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 773     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 774     int *segp)
 775 {
 776         bus_size_t sgsize, max_sgsize;
 777         vm_paddr_t curaddr;
 778         vm_offset_t kvaddr, vaddr;
 779         int error;
 780
 781         if (map == NULL)
 782                 map = &nobounce_dmamap;
 783
 784         if (segs == NULL)
 785                 segs = dmat->segments;
 786
 787         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 788                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 789                 if (map->pagesneeded != 0) {
 790                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 791                         if (error)
 792                                 return (error);
 793                 }
 794         }
 795
 796         vaddr = (vm_offset_t)buf;
 797         while (buflen > 0) {
 798                 /*
 799                  * Get the physical address for this segment.
 800                  */
 801                 if (pmap == kernel_pmap) {
 802                         curaddr = pmap_kextract(vaddr);
 803                         kvaddr = vaddr;
 804                 } else {
 805                         curaddr = pmap_extract(pmap, vaddr);
 806                         kvaddr = 0;
 807                 }
 808
 809                 /*
 810                  * Compute the segment size, and adjust counts.
 811                  */
 812                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 813                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 814                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 815                     map->pagesneeded != 0 &&
 816                     bus_dma_run_filter(&dmat->common, curaddr)) {
 817                         sgsize = roundup2(sgsize, dmat->common.alignment);
 818                         sgsize = MIN(sgsize, max_sgsize);
 819                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
 820                             sgsize);
 821                 } else {
 822                         sgsize = MIN(sgsize, max_sgsize);
 823                 }
 824                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 825                     segp);
 826                 if (sgsize == 0)
 827                         break;
 828                 vaddr += sgsize;
 829                 buflen -= sgsize;
 830         }
 831
 832         /*
 833          * Did we fit?
 834          */
 835         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 836 }
 837
 838 static int
 839 bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
 840     struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
 841     bus_dma_segment_t *segs, int *segp)
 842 {
 843         vm_paddr_t paddr, next_paddr;
 844         int error, page_index;
 845         bus_size_t sgsize, max_sgsize;
 846
 847         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 848                 /*
 849                  * If we have to keep the offset of each page this function
 850                  * is not suitable, switch back to bus_dmamap_load_ma_triv
 851                  * which is going to do the right thing in this case.
 852                  */
 853                 error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
 854                     flags, segs, segp);
 855                 return (error);
 856         }
 857
 858         if (map == NULL)
 859                 map = &nobounce_dmamap;
 860
 861         if (segs == NULL)
 862                 segs = dmat->segments;
 863
 864         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 865                 _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
 866                 if (map->pagesneeded != 0) {
 867                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 868                         if (error)
 869                                 return (error);
 870                 }
 871         }
 872
 873         page_index = 0;
 874         while (buflen > 0) {
 875                 /*
 876                  * Compute the segment size, and adjust counts.
 877                  */
 878                 paddr = VM_PAGE_TO_PHYS(ma[page_index]) + ma_offs;
 879                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 880                 sgsize = PAGE_SIZE - ma_offs;
 881                 if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0 &&
 882                     map->pagesneeded != 0 &&
 883                     bus_dma_run_filter(&dmat->common, paddr)) {
 884                         sgsize = roundup2(sgsize, dmat->common.alignment);
 885                         sgsize = MIN(sgsize, max_sgsize);
 886                         KASSERT(vm_addr_align_ok(sgsize,
 887                             dmat->common.alignment),
 888                             ("Segment size is not aligned"));
 889                         /*
 890                          * Check if two pages of the user provided buffer
 891                          * are used.
 892                          */
 893                         if ((ma_offs + sgsize) > PAGE_SIZE)
 894                                 next_paddr =
 895                                     VM_PAGE_TO_PHYS(ma[page_index + 1]);
 896                         else
 897                                 next_paddr = 0;
 898                         paddr = add_bounce_page(dmat, map, 0, paddr,
 899                             next_paddr, sgsize);
 900                 } else {
 901                         sgsize = MIN(sgsize, max_sgsize);
 902                 }
 903                 sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
 904                     segp);
 905                 if (sgsize == 0)
 906                         break;
 907                 KASSERT(buflen >= sgsize,
 908                     ("Segment length overruns original buffer"));
 909                 buflen -= sgsize;
 910                 if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
 911                         page_index++;
 912                 ma_offs = (ma_offs + sgsize) & PAGE_MASK;
 913         }
 914
 915         /*
 916          * Did we fit?
 917          */
 918         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 919 }
 920
 921 static void
 922 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 923     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 924 {
 925
 926         if (map == NULL)
 927                 return;
 928         map->mem = *mem;
 929         map->dmat = dmat;
 930         map->callback = callback;
 931         map->callback_arg = callback_arg;
 932 }
 933
 934 static bus_dma_segment_t *
 935 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 936     bus_dma_segment_t *segs, int nsegs, int error)
 937 {
 938
 939         if (segs == NULL)
 940                 segs = dmat->segments;
 941         return (segs);
 942 }
 943
 944 /*
 945  * Release the mapping held by map.
 946  */
 947 static void
 948 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 949 {
 950         struct bounce_page *bpage;
 951
 952         if (map == NULL)
 953                 return;
 954
 955         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 956                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 957                 free_bounce_page(dmat, bpage);
 958         }
 959 }
 960
 961 static void
 962 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 963     bus_dmasync_op_t op)
 964 {
 965         struct bounce_page *bpage;
 966         vm_offset_t datavaddr, tempvaddr;
 967         bus_size_t datacount1, datacount2;
 968
 969         if (map == NULL || (bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 970                 goto out;
 971
 972         /*
 973          * Handle data bouncing.  We might also want to add support for
 974          * invalidating the caches on broken hardware.
 975          */
 976         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 977             "performing bounce", __func__, dmat, dmat->common.flags, op);
 978
 979         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 980                 while (bpage != NULL) {
 981                         tempvaddr = 0;
 982                         datavaddr = bpage->datavaddr;
 983                         datacount1 = bpage->datacount;
 984                         if (datavaddr == 0) {
 985                                 tempvaddr =
 986                                     pmap_quick_enter_page(bpage->datapage[0]);
 987                                 datavaddr = tempvaddr | bpage->dataoffs;
 988                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
 989                                     datacount1);
 990                         }
 991
 992                         bcopy((void *)datavaddr,
 993                             (void *)bpage->vaddr, datacount1);
 994
 995                         if (tempvaddr != 0)
 996                                 pmap_quick_remove_page(tempvaddr);
 997
 998                         if (bpage->datapage[1] == 0) {
 999                                 KASSERT(datacount1 == bpage->datacount,
1000                 ("Mismatch between data size and provided memory space"));
1001                                 goto next_w;
1002                         }
1003
1004                         /*
1005                          * We are dealing with an unmapped buffer that expands
1006                          * over two pages.
1007                          */
1008                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1009                         datacount2 = bpage->datacount - datacount1;
1010                         bcopy((void *)datavaddr,
1011                             (void *)(bpage->vaddr + datacount1), datacount2);
1012                         pmap_quick_remove_page(datavaddr);
1013
1014 next_w:
1015                         bpage = STAILQ_NEXT(bpage, links);
1016                 }
1017                 dmat->bounce_zone->total_bounced++;
1018         }
1019
1020         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
1021                 while (bpage != NULL) {
1022                         tempvaddr = 0;
1023                         datavaddr = bpage->datavaddr;
1024                         datacount1 = bpage->datacount;
1025                         if (datavaddr == 0) {
1026                                 tempvaddr =
1027                                     pmap_quick_enter_page(bpage->datapage[0]);
1028                                 datavaddr = tempvaddr | bpage->dataoffs;
1029                                 datacount1 = min(PAGE_SIZE - bpage->dataoffs,
1030                                     datacount1);
1031                         }
1032
1033                         bcopy((void *)bpage->vaddr, (void *)datavaddr,
1034                             datacount1);
1035
1036                         if (tempvaddr != 0)
1037                                 pmap_quick_remove_page(tempvaddr);
1038
1039                         if (bpage->datapage[1] == 0) {
1040                                 KASSERT(datacount1 == bpage->datacount,
1041                 ("Mismatch between data size and provided memory space"));
1042                                 goto next_r;
1043                         }
1044
1045                         /*
1046                          * We are dealing with an unmapped buffer that expands
1047                          * over two pages.
1048                          */
1049                         datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
1050                         datacount2 = bpage->datacount - datacount1;
1051                         bcopy((void *)(bpage->vaddr + datacount1),
1052                             (void *)datavaddr, datacount2);
1053                         pmap_quick_remove_page(datavaddr);
1054
1055 next_r:
1056                         bpage = STAILQ_NEXT(bpage, links);
1057                 }
1058                 dmat->bounce_zone->total_bounced++;
1059         }
1060 out:
1061         atomic_thread_fence_rel();
1062 }
1063
1064 static void
1065 init_bounce_pages(void *dummy __unused)
1066 {
1067
1068         total_bpages = 0;
1069         STAILQ_INIT(&bounce_zone_list);
1070         STAILQ_INIT(&bounce_map_waitinglist);
1071         STAILQ_INIT(&bounce_map_callbacklist);
1072         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1073 }
1074 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1075
1076 static struct sysctl_ctx_list *
1077 busdma_sysctl_tree(struct bounce_zone *bz)
1078 {
1079
1080         return (&bz->sysctl_tree);
1081 }
1082
1083 static struct sysctl_oid *
1084 busdma_sysctl_tree_top(struct bounce_zone *bz)
1085 {
1086
1087         return (bz->sysctl_tree_top);
1088 }
1089
1090 static int
1091 alloc_bounce_zone(bus_dma_tag_t dmat)
1092 {
1093         struct bounce_zone *bz;
1094
1095         /* Check to see if we already have a suitable zone */
1096         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1097                 if (dmat->common.alignment <= bz->alignment &&
1098                     dmat->common.lowaddr >= bz->lowaddr &&
1099                     dmat->common.domain == bz->domain) {
1100                         dmat->bounce_zone = bz;
1101                         return (0);
1102                 }
1103         }
1104
1105         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1106             M_NOWAIT | M_ZERO)) == NULL)
1107                 return (ENOMEM);
1108
1109         STAILQ_INIT(&bz->bounce_page_list);
1110         bz->free_bpages = 0;
1111         bz->reserved_bpages = 0;
1112         bz->active_bpages = 0;
1113         bz->lowaddr = dmat->common.lowaddr;
1114         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
1115         bz->map_count = 0;
1116         bz->domain = dmat->common.domain;
1117         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1118         busdma_zonecount++;
1119         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1120         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1121         dmat->bounce_zone = bz;
1122
1123         sysctl_ctx_init(&bz->sysctl_tree);
1124         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1125             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1126             CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
1127         if (bz->sysctl_tree_top == NULL) {
1128                 sysctl_ctx_free(&bz->sysctl_tree);
1129                 return (0);     /* XXX error code? */
1130         }
1131
1132         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1133             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1134             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1135             "Total bounce pages");
1136         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1137             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1138             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1139             "Free bounce pages");
1140         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1141             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1142             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1143             "Reserved bounce pages");
1144         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1145             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1146             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1147             "Active bounce pages");
1148         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1149             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1150             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1151             "Total bounce requests");
1152         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1153             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1154             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1155             "Total bounce requests that were deferred");
1156         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1157             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1158             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1159         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
1160             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1161             "alignment", CTLFLAG_RD, &bz->alignment, "");
1162         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1163             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1164             "domain", CTLFLAG_RD, &bz->domain, 0,
1165             "memory domain");
1166
1167         return (0);
1168 }
1169
1170 static int
1171 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1172 {
1173         struct bounce_zone *bz;
1174         int count;
1175
1176         bz = dmat->bounce_zone;
1177         count = 0;
1178         while (numpages > 0) {
1179                 struct bounce_page *bpage;
1180
1181                 bpage = malloc_domainset(sizeof(*bpage), M_DEVBUF,
1182                     DOMAINSET_PREF(dmat->common.domain), M_NOWAIT | M_ZERO);
1183
1184                 if (bpage == NULL)
1185                         break;
1186                 bpage->vaddr = (vm_offset_t)contigmalloc_domainset(PAGE_SIZE,
1187                     M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), M_NOWAIT,
1188                     0ul, bz->lowaddr, PAGE_SIZE, 0);
1189                 if (bpage->vaddr == 0) {
1190                         free(bpage, M_DEVBUF);
1191                         break;
1192                 }
1193                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1194                 mtx_lock(&bounce_lock);
1195                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1196                 total_bpages++;
1197                 bz->total_bpages++;
1198                 bz->free_bpages++;
1199                 mtx_unlock(&bounce_lock);
1200                 count++;
1201                 numpages--;
1202         }
1203         return (count);
1204 }
1205
1206 static int
1207 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1208 {
1209         struct bounce_zone *bz;
1210         int pages;
1211
1212         mtx_assert(&bounce_lock, MA_OWNED);
1213         bz = dmat->bounce_zone;
1214         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1215         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1216                 return (map->pagesneeded - (map->pagesreserved + pages));
1217         bz->free_bpages -= pages;
1218         bz->reserved_bpages += pages;
1219         map->pagesreserved += pages;
1220         pages = map->pagesneeded - map->pagesreserved;
1221
1222         return (pages);
1223 }
1224
1225 static bus_addr_t
1226 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1227     vm_paddr_t addr1, vm_paddr_t addr2, bus_size_t size)
1228 {
1229         struct bounce_zone *bz;
1230         struct bounce_page *bpage;
1231
1232         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1233         KASSERT(map != NULL && map != &nobounce_dmamap,
1234             ("add_bounce_page: bad map %p", map));
1235
1236         bz = dmat->bounce_zone;
1237         if (map->pagesneeded == 0)
1238                 panic("add_bounce_page: map doesn't need any pages");
1239         map->pagesneeded--;
1240
1241         if (map->pagesreserved == 0)
1242                 panic("add_bounce_page: map doesn't need any pages");
1243         map->pagesreserved--;
1244
1245         mtx_lock(&bounce_lock);
1246         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1247         if (bpage == NULL)
1248                 panic("add_bounce_page: free page list is empty");
1249
1250         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1251         bz->reserved_bpages--;
1252         bz->active_bpages++;
1253         mtx_unlock(&bounce_lock);
1254
1255         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1256                 /* Page offset needs to be preserved. */
1257                 bpage->vaddr |= addr1 & PAGE_MASK;
1258                 bpage->busaddr |= addr1 & PAGE_MASK;
1259                 KASSERT(addr2 == 0,
1260         ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
1261         }
1262         bpage->datavaddr = vaddr;
1263         bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
1264         KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
1265         bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
1266         bpage->dataoffs = addr1 & PAGE_MASK;
1267         bpage->datacount = size;
1268         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1269         return (bpage->busaddr);
1270 }
1271
1272 static void
1273 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1274 {
1275         struct bus_dmamap *map;
1276         struct bounce_zone *bz;
1277         bool schedule_swi;
1278
1279         bz = dmat->bounce_zone;
1280         bpage->datavaddr = 0;
1281         bpage->datacount = 0;
1282         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1283                 /*
1284                  * Reset the bounce page to start at offset 0.  Other uses
1285                  * of this bounce page may need to store a full page of
1286                  * data and/or assume it starts on a page boundary.
1287                  */
1288                 bpage->vaddr &= ~PAGE_MASK;
1289                 bpage->busaddr &= ~PAGE_MASK;
1290         }
1291
1292         schedule_swi = false;
1293         mtx_lock(&bounce_lock);
1294         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1295         bz->free_bpages++;
1296         bz->active_bpages--;
1297         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1298                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1299                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1300                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1301                             map, links);
1302                         bz->total_deferred++;
1303                         schedule_swi = true;
1304                 }
1305         }
1306         mtx_unlock(&bounce_lock);
1307         if (schedule_swi)
1308                 swi_sched(busdma_ih, 0);
1309 }
1310
1311 static void
1312 busdma_swi(void *dummy __unused)
1313 {
1314         bus_dma_tag_t dmat;
1315         struct bus_dmamap *map;
1316
1317         mtx_lock(&bounce_lock);
1318         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1319                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1320                 mtx_unlock(&bounce_lock);
1321                 dmat = map->dmat;
1322                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1323                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1324                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1325                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1326                     BUS_DMA_UNLOCK);
1327                 mtx_lock(&bounce_lock);
1328         }
1329         mtx_unlock(&bounce_lock);
1330 }
1331
1332 static void
1333 start_busdma_swi(void *dummy __unused)
1334 {
1335         if (swi_add(NULL, "busdma", busdma_swi, NULL, SWI_BUSDMA, INTR_MPSAFE,
1336             &busdma_ih))
1337                 panic("died while creating busdma swi ithread");
1338 }
1339 SYSINIT(start_busdma_swi, SI_SUB_SOFTINTR, SI_ORDER_ANY, start_busdma_swi,
1340     NULL);
1341
1342 struct bus_dma_impl bus_dma_bounce_impl = {
1343         .tag_create = bounce_bus_dma_tag_create,
1344         .tag_destroy = bounce_bus_dma_tag_destroy,
1345         .tag_set_domain = bounce_bus_dma_tag_set_domain,
1346         .id_mapped = bounce_bus_dma_id_mapped,
1347         .map_create = bounce_bus_dmamap_create,
1348         .map_destroy = bounce_bus_dmamap_destroy,
1349         .mem_alloc = bounce_bus_dmamem_alloc,
1350         .mem_free = bounce_bus_dmamem_free,
1351         .load_phys = bounce_bus_dmamap_load_phys,
1352         .load_buffer = bounce_bus_dmamap_load_buffer,
1353         .load_ma = bounce_bus_dmamap_load_ma,
1354         .map_waitok = bounce_bus_dmamap_waitok,
1355         .map_complete = bounce_bus_dmamap_complete,
1356         .map_unload = bounce_bus_dmamap_unload,
1357         .map_sync = bounce_bus_dmamap_sync,
1358 };