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 #define BUS_DMA_COULD_BOUNCE    BUS_DMA_BUS3
  62 #define BUS_DMA_MIN_ALLOC_COMP  BUS_DMA_BUS4
  63
  64 struct bounce_zone;
  65
  66 struct bus_dma_tag {
  67         struct bus_dma_tag_common common;
  68         int               map_count;
  69         bus_dma_segment_t *segments;
  70         struct bounce_zone *bounce_zone;
  71 };
  72
  73 struct bounce_page {
  74         vm_offset_t     vaddr;          /* kva of bounce buffer */
  75         bus_addr_t      busaddr;        /* Physical address */
  76         vm_offset_t     datavaddr;      /* kva of client data */
  77         bus_addr_t      dataaddr;       /* client physical address */
  78         bus_size_t      datacount;      /* client data count */
  79         STAILQ_ENTRY(bounce_page) links;
  80 };
  81
  82 int busdma_swi_pending;
  83
  84 struct bounce_zone {
  85         STAILQ_ENTRY(bounce_zone) links;
  86         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  87         int             total_bpages;
  88         int             free_bpages;
  89         int             reserved_bpages;
  90         int             active_bpages;
  91         int             total_bounced;
  92         int             total_deferred;
  93         int             map_count;
  94         bus_size_t      alignment;
  95         bus_addr_t      lowaddr;
  96         char            zoneid[8];
  97         char            lowaddrid[20];
  98         struct sysctl_ctx_list sysctl_tree;
  99         struct sysctl_oid *sysctl_tree_top;
 100 };
 101
 102 static struct mtx bounce_lock;
 103 static int total_bpages;
 104 static int busdma_zonecount;
 105 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
 106
 107 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 108 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 109            "Total bounce pages");
 110
 111 struct bus_dmamap {
 112         struct bp_list         bpages;
 113         int                    pagesneeded;
 114         int                    pagesreserved;
 115         bus_dma_tag_t          dmat;
 116         struct memdesc         mem;
 117         bus_dmamap_callback_t *callback;
 118         void                  *callback_arg;
 119         STAILQ_ENTRY(bus_dmamap) links;
 120 };
 121
 122 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 123 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 124 static struct bus_dmamap nobounce_dmamap, contig_dmamap;
 125
 126 static void init_bounce_pages(void *dummy);
 127 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 128 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 129 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 130                                 int commit);
 131 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 132                                   vm_offset_t vaddr, bus_addr_t addr,
 133                                   bus_size_t size);
 134 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 135 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 136 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 137                                     pmap_t pmap, void *buf, bus_size_t buflen,
 138                                     int flags);
 139 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 140                                    vm_paddr_t buf, bus_size_t buflen,
 141                                    int flags);
 142 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 143                                      int flags);
 144
 145 #ifdef XEN
 146 #undef pmap_kextract
 147 #define pmap_kextract pmap_kextract_ma
 148 #endif
 149
 150 /*
 151  * Allocate a device specific dma_tag.
 152  */
 153 static int
 154 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 155     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 156     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 157     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 158     void *lockfuncarg, bus_dma_tag_t *dmat)
 159 {
 160         bus_dma_tag_t newtag;
 161         int error;
 162
 163         *dmat = NULL;
 164         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 165             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 166             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 167             sizeof (struct bus_dma_tag), (void **)&newtag);
 168         if (error != 0)
 169                 return (error);
 170
 171         newtag->common.impl = &bus_dma_bounce_impl;
 172         newtag->map_count = 0;
 173         newtag->segments = NULL;
 174
 175         if (parent != NULL && ((newtag->common.filter != NULL) ||
 176             ((parent->common.flags & BUS_DMA_COULD_BOUNCE) != 0)))
 177                 newtag->common.flags |= BUS_DMA_COULD_BOUNCE;
 178
 179         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 180             newtag->common.alignment > 1)
 181                 newtag->common.flags |= BUS_DMA_COULD_BOUNCE;
 182
 183         if (((newtag->common.flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 184             (flags & BUS_DMA_ALLOCNOW) != 0) {
 185                 struct bounce_zone *bz;
 186
 187                 /* Must bounce */
 188                 if ((error = alloc_bounce_zone(newtag)) != 0) {
 189                         free(newtag, M_DEVBUF);
 190                         return (error);
 191                 }
 192                 bz = newtag->bounce_zone;
 193
 194                 if (ptoa(bz->total_bpages) < maxsize) {
 195                         int pages;
 196
 197                         pages = atop(maxsize) - bz->total_bpages;
 198
 199                         /* Add pages to our bounce pool */
 200                         if (alloc_bounce_pages(newtag, pages) < pages)
 201                                 error = ENOMEM;
 202                 }
 203                 /* Performed initial allocation */
 204                 newtag->common.flags |= BUS_DMA_MIN_ALLOC_COMP;
 205         } else
 206                 error = 0;
 207
 208         if (error != 0)
 209                 free(newtag, M_DEVBUF);
 210         else
 211                 *dmat = newtag;
 212         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 213             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 214             error);
 215         return (error);
 216 }
 217
 218 static int
 219 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 220 {
 221         bus_dma_tag_t dmat_copy, parent;
 222         int error;
 223
 224         error = 0;
 225         dmat_copy = dmat;
 226
 227         if (dmat != NULL) {
 228                 if (dmat->map_count != 0) {
 229                         error = EBUSY;
 230                         goto out;
 231                 }
 232                 while (dmat != NULL) {
 233                         parent = (bus_dma_tag_t)dmat->common.parent;
 234                         atomic_subtract_int(&dmat->common.ref_count, 1);
 235                         if (dmat->common.ref_count == 0) {
 236                                 if (dmat->segments != NULL)
 237                                         free(dmat->segments, M_DEVBUF);
 238                                 free(dmat, M_DEVBUF);
 239                                 /*
 240                                  * Last reference count, so
 241                                  * release our reference
 242                                  * count on our parent.
 243                                  */
 244                                 dmat = parent;
 245                         } else
 246                                 dmat = NULL;
 247                 }
 248         }
 249 out:
 250         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 251         return (error);
 252 }
 253
 254 /*
 255  * Allocate a handle for mapping from kva/uva/physical
 256  * address space into bus device space.
 257  */
 258 static int
 259 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 260 {
 261         struct bounce_zone *bz;
 262         int error, maxpages, pages;
 263
 264         error = 0;
 265
 266         if (dmat->segments == NULL) {
 267                 dmat->segments = (bus_dma_segment_t *)malloc(
 268                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 269                     M_DEVBUF, M_NOWAIT);
 270                 if (dmat->segments == NULL) {
 271                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 272                             __func__, dmat, ENOMEM);
 273                         return (ENOMEM);
 274                 }
 275         }
 276
 277         /*
 278          * Bouncing might be required if the driver asks for an active
 279          * exclusion region, a data alignment that is stricter than 1, and/or
 280          * an active address boundary.
 281          */
 282         if (dmat->common.flags & BUS_DMA_COULD_BOUNCE) {
 283                 /* Must bounce */
 284                 if (dmat->bounce_zone == NULL) {
 285                         if ((error = alloc_bounce_zone(dmat)) != 0)
 286                                 return (error);
 287                 }
 288                 bz = dmat->bounce_zone;
 289
 290                 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 291                     M_NOWAIT | M_ZERO);
 292                 if (*mapp == NULL) {
 293                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 294                             __func__, dmat, ENOMEM);
 295                         return (ENOMEM);
 296                 }
 297
 298                 /* Initialize the new map */
 299                 STAILQ_INIT(&((*mapp)->bpages));
 300
 301                 /*
 302                  * Attempt to add pages to our pool on a per-instance
 303                  * basis up to a sane limit.
 304                  */
 305                 if (dmat->common.alignment > 1)
 306                         maxpages = MAX_BPAGES;
 307                 else
 308                         maxpages = MIN(MAX_BPAGES, Maxmem -
 309                             atop(dmat->common.lowaddr));
 310                 if ((dmat->common.flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 311                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 312                         pages = MAX(atop(dmat->common.maxsize), 1);
 313                         pages = MIN(maxpages - bz->total_bpages, pages);
 314                         pages = MAX(pages, 1);
 315                         if (alloc_bounce_pages(dmat, pages) < pages)
 316                                 error = ENOMEM;
 317                         if ((dmat->common.flags & BUS_DMA_MIN_ALLOC_COMP)
 318                             == 0) {
 319                                 if (error == 0) {
 320                                         dmat->common.flags |=
 321                                             BUS_DMA_MIN_ALLOC_COMP;
 322                                 }
 323                         } else
 324                                 error = 0;
 325                 }
 326                 bz->map_count++;
 327         } else {
 328                 *mapp = NULL;
 329         }
 330         if (error == 0)
 331                 dmat->map_count++;
 332         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 333             __func__, dmat, dmat->common.flags, error);
 334         return (error);
 335 }
 336
 337 /*
 338  * Destroy a handle for mapping from kva/uva/physical
 339  * address space into bus device space.
 340  */
 341 static int
 342 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 343 {
 344
 345         if (map != NULL && map != &nobounce_dmamap && map != &contig_dmamap) {
 346                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 347                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 348                             __func__, dmat, EBUSY);
 349                         return (EBUSY);
 350                 }
 351                 if (dmat->bounce_zone)
 352                         dmat->bounce_zone->map_count--;
 353                 free(map, M_DEVBUF);
 354         }
 355         dmat->map_count--;
 356         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 357         return (0);
 358 }
 359
 360
 361 /*
 362  * Allocate a piece of memory that can be efficiently mapped into
 363  * bus device space based on the constraints lited in the dma tag.
 364  * A dmamap to for use with dmamap_load is also allocated.
 365  */
 366 static int
 367 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 368     bus_dmamap_t *mapp)
 369 {
 370         vm_memattr_t attr;
 371         int mflags;
 372
 373         if (flags & BUS_DMA_NOWAIT)
 374                 mflags = M_NOWAIT;
 375         else
 376                 mflags = M_WAITOK;
 377
 378         /* If we succeed, no mapping/bouncing will be required */
 379         *mapp = NULL;
 380
 381         if (dmat->segments == NULL) {
 382                 dmat->segments = (bus_dma_segment_t *)malloc(
 383                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 384                     M_DEVBUF, mflags);
 385                 if (dmat->segments == NULL) {
 386                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 387                             __func__, dmat, dmat->common.flags, ENOMEM);
 388                         return (ENOMEM);
 389                 }
 390         }
 391         if (flags & BUS_DMA_ZERO)
 392                 mflags |= M_ZERO;
 393         if (flags & BUS_DMA_NOCACHE)
 394                 attr = VM_MEMATTR_UNCACHEABLE;
 395         else
 396                 attr = VM_MEMATTR_DEFAULT;
 397
 398         /*
 399          * XXX:
 400          * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
 401          * alignment guarantees of malloc need to be nailed down, and the
 402          * code below should be rewritten to take that into account.
 403          *
 404          * In the meantime, we'll warn the user if malloc gets it wrong.
 405          */
 406         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 407            (dmat->common.alignment < dmat->common.maxsize) &&
 408             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 409             attr == VM_MEMATTR_DEFAULT) {
 410                 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
 411         } else if (dmat->common.nsegments >= btoc(dmat->common.maxsize) &&
 412             dmat->common.alignment <= PAGE_SIZE &&
 413             (dmat->common.boundary == 0 ||
 414             dmat->common.boundary >= dmat->common.lowaddr)) {
 415                 /* Page-based multi-segment allocations allowed */
 416                 *vaddr = (void *)kmem_alloc_attr(kernel_arena,
 417                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 418                     attr);
 419                 *mapp = &contig_dmamap;
 420         } else {
 421                 *vaddr = (void *)kmem_alloc_contig(kernel_arena,
 422                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 423                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 424                     dmat->common.boundary, attr);
 425                 *mapp = &contig_dmamap;
 426         }
 427         if (*vaddr == NULL) {
 428                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 429                     __func__, dmat, dmat->common.flags, ENOMEM);
 430                 return (ENOMEM);
 431         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 432                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 433         }
 434         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 435             __func__, dmat, dmat->common.flags, 0);
 436         return (0);
 437 }
 438
 439 /*
 440  * Free a piece of memory and it's allociated dmamap, that was allocated
 441  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 442  */
 443 static void
 444 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 445 {
 446         /*
 447          * dmamem does not need to be bounced, so the map should be
 448          * NULL if malloc() was used and contig_dmamap if
 449          * kmem_alloc_contig() was used.
 450          */
 451         if (!(map == NULL || map == &contig_dmamap))
 452                 panic("bus_dmamem_free: Invalid map freed\n");
 453         if (map == NULL)
 454                 free(vaddr, M_DEVBUF);
 455         else
 456                 kmem_free(kernel_arena, (vm_offset_t)vaddr,
 457                     dmat->common.maxsize);
 458         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 459             dmat->common.flags);
 460 }
 461
 462 static void
 463 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 464     bus_size_t buflen, int flags)
 465 {
 466         bus_addr_t curaddr;
 467         bus_size_t sgsize;
 468
 469         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 470                 /*
 471                  * Count the number of bounce pages
 472                  * needed in order to complete this transfer
 473                  */
 474                 curaddr = buf;
 475                 while (buflen != 0) {
 476                         sgsize = MIN(buflen, dmat->common.maxsegsz);
 477                         if (bus_dma_run_filter(&dmat->common, curaddr)) {
 478                                 sgsize = MIN(sgsize, PAGE_SIZE);
 479                                 map->pagesneeded++;
 480                         }
 481                         curaddr += sgsize;
 482                         buflen -= sgsize;
 483                 }
 484                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 485         }
 486 }
 487
 488 static void
 489 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 490     void *buf, bus_size_t buflen, int flags)
 491 {
 492         vm_offset_t vaddr;
 493         vm_offset_t vendaddr;
 494         bus_addr_t paddr;
 495         bus_size_t sg_len;
 496
 497         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 498                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 499                     "alignment= %d", dmat->common.lowaddr,
 500                     ptoa((vm_paddr_t)Maxmem),
 501                     dmat->common.boundary, dmat->common.alignment);
 502                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 503                     map, &nobounce_dmamap, map->pagesneeded);
 504                 /*
 505                  * Count the number of bounce pages
 506                  * needed in order to complete this transfer
 507                  */
 508                 vaddr = (vm_offset_t)buf;
 509                 vendaddr = (vm_offset_t)buf + buflen;
 510
 511                 while (vaddr < vendaddr) {
 512                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 513                         if (pmap == kernel_pmap)
 514                                 paddr = pmap_kextract(vaddr);
 515                         else
 516                                 paddr = pmap_extract(pmap, vaddr);
 517                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 518                                 sg_len = roundup2(sg_len,
 519                                     dmat->common.alignment);
 520                                 map->pagesneeded++;
 521                         }
 522                         vaddr += sg_len;
 523                 }
 524                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 525         }
 526 }
 527
 528 static int
 529 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 530 {
 531
 532         /* Reserve Necessary Bounce Pages */
 533         mtx_lock(&bounce_lock);
 534         if (flags & BUS_DMA_NOWAIT) {
 535                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 536                         mtx_unlock(&bounce_lock);
 537                         return (ENOMEM);
 538                 }
 539         } else {
 540                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 541                         /* Queue us for resources */
 542                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 543                         mtx_unlock(&bounce_lock);
 544                         return (EINPROGRESS);
 545                 }
 546         }
 547         mtx_unlock(&bounce_lock);
 548
 549         return (0);
 550 }
 551
 552 /*
 553  * Add a single contiguous physical range to the segment list.
 554  */
 555 static int
 556 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 557     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 558 {
 559         bus_addr_t baddr, bmask;
 560         int seg;
 561
 562         /*
 563          * Make sure we don't cross any boundaries.
 564          */
 565         bmask = ~(dmat->common.boundary - 1);
 566         if (dmat->common.boundary > 0) {
 567                 baddr = (curaddr + dmat->common.boundary) & bmask;
 568                 if (sgsize > (baddr - curaddr))
 569                         sgsize = (baddr - curaddr);
 570         }
 571
 572         /*
 573          * Insert chunk into a segment, coalescing with
 574          * previous segment if possible.
 575          */
 576         seg = *segp;
 577         if (seg == -1) {
 578                 seg = 0;
 579                 segs[seg].ds_addr = curaddr;
 580                 segs[seg].ds_len = sgsize;
 581         } else {
 582                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 583                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 584                     (dmat->common.boundary == 0 ||
 585                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 586                         segs[seg].ds_len += sgsize;
 587                 else {
 588                         if (++seg >= dmat->common.nsegments)
 589                                 return (0);
 590                         segs[seg].ds_addr = curaddr;
 591                         segs[seg].ds_len = sgsize;
 592                 }
 593         }
 594         *segp = seg;
 595         return (sgsize);
 596 }
 597
 598 /*
 599  * Utility function to load a physical buffer.  segp contains
 600  * the starting segment on entrace, and the ending segment on exit.
 601  */
 602 static int
 603 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 604     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 605     int *segp)
 606 {
 607         bus_size_t sgsize;
 608         bus_addr_t curaddr;
 609         int error;
 610
 611         if (map == NULL || map == &contig_dmamap)
 612                 map = &nobounce_dmamap;
 613
 614         if (segs == NULL)
 615                 segs = dmat->segments;
 616
 617         if ((dmat->common.flags & BUS_DMA_COULD_BOUNCE) != 0) {
 618                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 619                 if (map->pagesneeded != 0) {
 620                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 621                         if (error)
 622                                 return (error);
 623                 }
 624         }
 625
 626         while (buflen > 0) {
 627                 curaddr = buf;
 628                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 629                 if (((dmat->common.flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 630                     map->pagesneeded != 0 &&
 631                     bus_dma_run_filter(&dmat->common, curaddr)) {
 632                         sgsize = MIN(sgsize, PAGE_SIZE);
 633                         curaddr = add_bounce_page(dmat, map, 0, curaddr,
 634                             sgsize);
 635                 }
 636                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 637                     segp);
 638                 if (sgsize == 0)
 639                         break;
 640                 buf += sgsize;
 641                 buflen -= sgsize;
 642         }
 643
 644         /*
 645          * Did we fit?
 646          */
 647         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 648 }
 649
 650 /*
 651  * Utility function to load a linear buffer.  segp contains
 652  * the starting segment on entrace, and the ending segment on exit.
 653  */
 654 static int
 655 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 656     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 657     int *segp)
 658 {
 659         bus_size_t sgsize, max_sgsize;
 660         bus_addr_t curaddr;
 661         vm_offset_t vaddr;
 662         int error;
 663
 664         if (map == NULL || map == &contig_dmamap)
 665                 map = &nobounce_dmamap;
 666
 667         if (segs == NULL)
 668                 segs = dmat->segments;
 669
 670         if ((dmat->common.flags & BUS_DMA_COULD_BOUNCE) != 0) {
 671                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 672                 if (map->pagesneeded != 0) {
 673                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 674                         if (error)
 675                                 return (error);
 676                 }
 677         }
 678
 679         vaddr = (vm_offset_t)buf;
 680         while (buflen > 0) {
 681                 /*
 682                  * Get the physical address for this segment.
 683                  */
 684                 if (pmap == kernel_pmap)
 685                         curaddr = pmap_kextract(vaddr);
 686                 else
 687                         curaddr = pmap_extract(pmap, vaddr);
 688
 689                 /*
 690                  * Compute the segment size, and adjust counts.
 691                  */
 692                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 693                 sgsize = PAGE_SIZE - ((vm_offset_t)curaddr & PAGE_MASK);
 694                 if (((dmat->common.flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 695                     map->pagesneeded != 0 &&
 696                     bus_dma_run_filter(&dmat->common, curaddr)) {
 697                         sgsize = roundup2(sgsize, dmat->common.alignment);
 698                         sgsize = MIN(sgsize, max_sgsize);
 699                         curaddr = add_bounce_page(dmat, map, vaddr, curaddr,
 700                             sgsize);
 701                 } else {
 702                         sgsize = MIN(sgsize, max_sgsize);
 703                 }
 704                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 705                     segp);
 706                 if (sgsize == 0)
 707                         break;
 708                 vaddr += sgsize;
 709                 buflen -= sgsize;
 710         }
 711
 712         /*
 713          * Did we fit?
 714          */
 715         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 716 }
 717
 718 static void
 719 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 720     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 721 {
 722
 723         if (map == NULL)
 724                 return;
 725         map->mem = *mem;
 726         map->dmat = dmat;
 727         map->callback = callback;
 728         map->callback_arg = callback_arg;
 729 }
 730
 731 static bus_dma_segment_t *
 732 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 733     bus_dma_segment_t *segs, int nsegs, int error)
 734 {
 735
 736         if (segs == NULL)
 737                 segs = dmat->segments;
 738         return (segs);
 739 }
 740
 741 /*
 742  * Release the mapping held by map.
 743  */
 744 static void
 745 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 746 {
 747         struct bounce_page *bpage;
 748
 749         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 750                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 751                 free_bounce_page(dmat, bpage);
 752         }
 753 }
 754
 755 static void
 756 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 757     bus_dmasync_op_t op)
 758 {
 759         struct bounce_page *bpage;
 760
 761         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 762                 /*
 763                  * Handle data bouncing.  We might also
 764                  * want to add support for invalidating
 765                  * the caches on broken hardware
 766                  */
 767                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 768                     "performing bounce", __func__, dmat,
 769                     dmat->common.flags, op);
 770
 771                 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 772                         while (bpage != NULL) {
 773                                 if (bpage->datavaddr != 0) {
 774                                         bcopy((void *)bpage->datavaddr,
 775                                             (void *)bpage->vaddr,
 776                                             bpage->datacount);
 777                                 } else {
 778                                         physcopyout(bpage->dataaddr,
 779                                             (void *)bpage->vaddr,
 780                                             bpage->datacount);
 781                                 }
 782                                 bpage = STAILQ_NEXT(bpage, links);
 783                         }
 784                         dmat->bounce_zone->total_bounced++;
 785                 }
 786
 787                 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
 788                         while (bpage != NULL) {
 789                                 if (bpage->datavaddr != 0) {
 790                                         bcopy((void *)bpage->vaddr,
 791                                             (void *)bpage->datavaddr,
 792                                             bpage->datacount);
 793                                 } else {
 794                                         physcopyin((void *)bpage->vaddr,
 795                                             bpage->dataaddr,
 796                                             bpage->datacount);
 797                                 }
 798                                 bpage = STAILQ_NEXT(bpage, links);
 799                         }
 800                         dmat->bounce_zone->total_bounced++;
 801                 }
 802         }
 803 }
 804
 805 static void
 806 init_bounce_pages(void *dummy __unused)
 807 {
 808
 809         total_bpages = 0;
 810         STAILQ_INIT(&bounce_zone_list);
 811         STAILQ_INIT(&bounce_map_waitinglist);
 812         STAILQ_INIT(&bounce_map_callbacklist);
 813         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
 814 }
 815 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
 816
 817 static struct sysctl_ctx_list *
 818 busdma_sysctl_tree(struct bounce_zone *bz)
 819 {
 820         return (&bz->sysctl_tree);
 821 }
 822
 823 static struct sysctl_oid *
 824 busdma_sysctl_tree_top(struct bounce_zone *bz)
 825 {
 826         return (bz->sysctl_tree_top);
 827 }
 828
 829 #if defined(__amd64__) || defined(PAE)
 830 #define SYSCTL_ADD_BUS_SIZE_T   SYSCTL_ADD_UQUAD
 831 #else
 832 #define SYSCTL_ADD_BUS_SIZE_T(ctx, parent, nbr, name, flag, ptr, desc)  \
 833         SYSCTL_ADD_UINT(ctx, parent, nbr, name, flag, ptr, 0, desc)
 834 #endif
 835
 836 static int
 837 alloc_bounce_zone(bus_dma_tag_t dmat)
 838 {
 839         struct bounce_zone *bz;
 840
 841         /* Check to see if we already have a suitable zone */
 842         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
 843                 if ((dmat->common.alignment <= bz->alignment) &&
 844                     (dmat->common.lowaddr >= bz->lowaddr)) {
 845                         dmat->bounce_zone = bz;
 846                         return (0);
 847                 }
 848         }
 849
 850         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
 851             M_NOWAIT | M_ZERO)) == NULL)
 852                 return (ENOMEM);
 853
 854         STAILQ_INIT(&bz->bounce_page_list);
 855         bz->free_bpages = 0;
 856         bz->reserved_bpages = 0;
 857         bz->active_bpages = 0;
 858         bz->lowaddr = dmat->common.lowaddr;
 859         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
 860         bz->map_count = 0;
 861         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
 862         busdma_zonecount++;
 863         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
 864         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
 865         dmat->bounce_zone = bz;
 866
 867         sysctl_ctx_init(&bz->sysctl_tree);
 868         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
 869             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
 870             CTLFLAG_RD, 0, "");
 871         if (bz->sysctl_tree_top == NULL) {
 872                 sysctl_ctx_free(&bz->sysctl_tree);
 873                 return (0);     /* XXX error code? */
 874         }
 875
 876         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 877             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 878             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
 879             "Total bounce pages");
 880         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 881             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 882             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
 883             "Free bounce pages");
 884         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 885             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 886             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
 887             "Reserved bounce pages");
 888         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 889             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 890             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
 891             "Active bounce pages");
 892         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 893             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 894             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
 895             "Total bounce requests");
 896         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 897             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 898             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
 899             "Total bounce requests that were deferred");
 900         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
 901             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 902             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
 903         SYSCTL_ADD_BUS_SIZE_T(busdma_sysctl_tree(bz),
 904             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 905             "alignment", CTLFLAG_RD, &bz->alignment, "");
 906
 907         return (0);
 908 }
 909
 910 static int
 911 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 912 {
 913         struct bounce_zone *bz;
 914         int count;
 915
 916         bz = dmat->bounce_zone;
 917         count = 0;
 918         while (numpages > 0) {
 919                 struct bounce_page *bpage;
 920
 921                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
 922                                                      M_NOWAIT | M_ZERO);
 923
 924                 if (bpage == NULL)
 925                         break;
 926                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 927                                                          M_NOWAIT, 0ul,
 928                                                          bz->lowaddr,
 929                                                          PAGE_SIZE,
 930                                                          0);
 931                 if (bpage->vaddr == 0) {
 932                         free(bpage, M_DEVBUF);
 933                         break;
 934                 }
 935                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 936                 mtx_lock(&bounce_lock);
 937                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
 938                 total_bpages++;
 939                 bz->total_bpages++;
 940                 bz->free_bpages++;
 941                 mtx_unlock(&bounce_lock);
 942                 count++;
 943                 numpages--;
 944         }
 945         return (count);
 946 }
 947
 948 static int
 949 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
 950 {
 951         struct bounce_zone *bz;
 952         int pages;
 953
 954         mtx_assert(&bounce_lock, MA_OWNED);
 955         bz = dmat->bounce_zone;
 956         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
 957         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
 958                 return (map->pagesneeded - (map->pagesreserved + pages));
 959         bz->free_bpages -= pages;
 960         bz->reserved_bpages += pages;
 961         map->pagesreserved += pages;
 962         pages = map->pagesneeded - map->pagesreserved;
 963
 964         return (pages);
 965 }
 966
 967 static bus_addr_t
 968 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 969                 bus_addr_t addr, bus_size_t size)
 970 {
 971         struct bounce_zone *bz;
 972         struct bounce_page *bpage;
 973
 974         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
 975         KASSERT(map != NULL && map != &nobounce_dmamap && map != &contig_dmamap,
 976             ("add_bounce_page: bad map %p", map));
 977
 978         bz = dmat->bounce_zone;
 979         if (map->pagesneeded == 0)
 980                 panic("add_bounce_page: map doesn't need any pages");
 981         map->pagesneeded--;
 982
 983         if (map->pagesreserved == 0)
 984                 panic("add_bounce_page: map doesn't need any pages");
 985         map->pagesreserved--;
 986
 987         mtx_lock(&bounce_lock);
 988         bpage = STAILQ_FIRST(&bz->bounce_page_list);
 989         if (bpage == NULL)
 990                 panic("add_bounce_page: free page list is empty");
 991
 992         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
 993         bz->reserved_bpages--;
 994         bz->active_bpages++;
 995         mtx_unlock(&bounce_lock);
 996
 997         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 998                 /* Page offset needs to be preserved. */
 999                 bpage->vaddr |= vaddr & PAGE_MASK;
1000                 bpage->busaddr |= vaddr & PAGE_MASK;
1001         }
1002         bpage->datavaddr = vaddr;
1003         bpage->dataaddr = addr;
1004         bpage->datacount = size;
1005         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1006         return (bpage->busaddr);
1007 }
1008
1009 static void
1010 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1011 {
1012         struct bus_dmamap *map;
1013         struct bounce_zone *bz;
1014
1015         bz = dmat->bounce_zone;
1016         bpage->datavaddr = 0;
1017         bpage->datacount = 0;
1018         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1019                 /*
1020                  * Reset the bounce page to start at offset 0.  Other uses
1021                  * of this bounce page may need to store a full page of
1022                  * data and/or assume it starts on a page boundary.
1023                  */
1024                 bpage->vaddr &= ~PAGE_MASK;
1025                 bpage->busaddr &= ~PAGE_MASK;
1026         }
1027
1028         mtx_lock(&bounce_lock);
1029         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1030         bz->free_bpages++;
1031         bz->active_bpages--;
1032         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1033                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1034                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1035                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1036                             map, links);
1037                         busdma_swi_pending = 1;
1038                         bz->total_deferred++;
1039                         swi_sched(vm_ih, 0);
1040                 }
1041         }
1042         mtx_unlock(&bounce_lock);
1043 }
1044
1045 void
1046 busdma_swi(void)
1047 {
1048         bus_dma_tag_t dmat;
1049         struct bus_dmamap *map;
1050
1051         mtx_lock(&bounce_lock);
1052         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1053                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1054                 mtx_unlock(&bounce_lock);
1055                 dmat = map->dmat;
1056                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1057                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1058                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1059                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1060                     BUS_DMA_UNLOCK);
1061                 mtx_lock(&bounce_lock);
1062         }
1063         mtx_unlock(&bounce_lock);
1064 }
1065
1066 struct bus_dma_impl bus_dma_bounce_impl = {
1067         .tag_create = bounce_bus_dma_tag_create,
1068         .tag_destroy = bounce_bus_dma_tag_destroy,
1069         .map_create = bounce_bus_dmamap_create,
1070         .map_destroy = bounce_bus_dmamap_destroy,
1071         .mem_alloc = bounce_bus_dmamem_alloc,
1072         .mem_free = bounce_bus_dmamem_free,
1073         .load_phys = bounce_bus_dmamap_load_phys,
1074         .load_buffer = bounce_bus_dmamap_load_buffer,
1075         .load_ma = bus_dmamap_load_ma_triv,
1076         .map_waitok = bounce_bus_dmamap_waitok,
1077         .map_complete = bounce_bus_dmamap_complete,
1078         .map_unload = bounce_bus_dmamap_unload,
1079         .map_sync = bounce_bus_dmamap_sync
1080 };