sys/platform/pc32/i386/busdma_machdep.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  * $FreeBSD: src/sys/i386/i386/busdma_machdep.c,v 1.94 2008/08/15 20:51:31 kmacy Exp $
  27  * $DragonFly: src/sys/platform/pc32/i386/busdma_machdep.c,v 1.23 2008/06/05 18:06:32 swildner Exp $
  28  */
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/malloc.h>
  33 #include <sys/mbuf.h>
  34 #include <sys/uio.h>
  35 #include <sys/bus_dma.h>
  36 #include <sys/kernel.h>
  37 #include <sys/sysctl.h>
  38 #include <sys/lock.h>
  39
  40 #include <sys/thread2.h>
  41 #include <sys/spinlock2.h>
  42 #include <sys/mplock2.h>
  43
  44 #include <vm/vm.h>
  45 #include <vm/vm_page.h>
  46
  47 /* XXX needed for to access pmap to convert per-proc virtual to physical */
  48 #include <sys/proc.h>
  49 #include <sys/lock.h>
  50 #include <vm/vm_map.h>
  51
  52 #include <machine/md_var.h>
  53
  54 #define MAX_BPAGES      1024
  55
  56 /*
  57  * 16 x N declared on stack.
  58  */
  59 #define BUS_DMA_CACHE_SEGMENTS  8
  60
  61 struct bounce_zone;
  62 struct bus_dmamap;
  63
  64 struct bus_dma_tag {
  65         bus_dma_tag_t   parent;
  66         bus_size_t      alignment;
  67         bus_size_t      boundary;
  68         bus_addr_t      lowaddr;
  69         bus_addr_t      highaddr;
  70         bus_dma_filter_t *filter;
  71         void            *filterarg;
  72         bus_size_t      maxsize;
  73         u_int           nsegments;
  74         bus_size_t      maxsegsz;
  75         int             flags;
  76         int             ref_count;
  77         int             map_count;
  78         bus_dma_segment_t *segments;
  79         struct bounce_zone *bounce_zone;
  80 #ifdef SMP
  81         struct spinlock spin;
  82 #else
  83         int             unused0;
  84 #endif
  85 };
  86
  87 /*
  88  * bus_dma_tag private flags
  89  */
  90 #define BUS_DMA_BOUNCE_ALIGN    BUS_DMA_BUS2
  91 #define BUS_DMA_BOUNCE_LOWADDR  BUS_DMA_BUS3
  92 #define BUS_DMA_MIN_ALLOC_COMP  BUS_DMA_BUS4
  93
  94 #define BUS_DMA_COULD_BOUNCE    (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
  95
  96 #define BUS_DMAMEM_KMALLOC(dmat) \
  97         ((dmat)->maxsize <= PAGE_SIZE && \
  98          (dmat)->alignment <= PAGE_SIZE && \
  99          (dmat)->lowaddr >= ptoa(Maxmem))
 100
 101 struct bounce_page {
 102         vm_offset_t     vaddr;          /* kva of bounce buffer */
 103         bus_addr_t      busaddr;        /* Physical address */
 104         vm_offset_t     datavaddr;      /* kva of client data */
 105         bus_size_t      datacount;      /* client data count */
 106         STAILQ_ENTRY(bounce_page) links;
 107 };
 108
 109 struct bounce_zone {
 110         STAILQ_ENTRY(bounce_zone) links;
 111         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
 112         STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 113 #ifdef SMP
 114         struct spinlock spin;
 115 #else
 116         int             unused0;
 117 #endif
 118         int             total_bpages;
 119         int             free_bpages;
 120         int             reserved_bpages;
 121         int             active_bpages;
 122         int             total_bounced;
 123         int             total_deferred;
 124         int             reserve_failed;
 125         bus_size_t      alignment;
 126         bus_addr_t      lowaddr;
 127         char            zoneid[8];
 128         char            lowaddrid[20];
 129         struct sysctl_ctx_list sysctl_ctx;
 130         struct sysctl_oid *sysctl_tree;
 131 };
 132
 133 #ifdef SMP
 134 #define BZ_LOCK(bz)     spin_lock(&(bz)->spin)
 135 #define BZ_UNLOCK(bz)   spin_unlock(&(bz)->spin)
 136 #else
 137 #define BZ_LOCK(bz)     crit_enter()
 138 #define BZ_UNLOCK(bz)   crit_exit()
 139 #endif
 140
 141 static struct lwkt_token bounce_zone_tok =
 142         LWKT_TOKEN_INITIALIZER(bounce_zone_tok);
 143 static int busdma_zonecount;
 144 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
 145         STAILQ_HEAD_INITIALIZER(bounce_zone_list);
 146
 147 static int busdma_priv_zonecount = -1;
 148
 149 int busdma_swi_pending;
 150 static int total_bounce_pages;
 151 static int max_bounce_pages = MAX_BPAGES;
 152 static int bounce_alignment = 1; /* XXX temporary */
 153
 154 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
 155 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
 156
 157 struct bus_dmamap {
 158         struct bp_list  bpages;
 159         int             pagesneeded;
 160         int             pagesreserved;
 161         bus_dma_tag_t   dmat;
 162         void            *buf;           /* unmapped buffer pointer */
 163         bus_size_t      buflen;         /* unmapped buffer length */
 164         bus_dmamap_callback_t *callback;
 165         void            *callback_arg;
 166         STAILQ_ENTRY(bus_dmamap) links;
 167 };
 168
 169 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
 170         STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
 171 static struct spinlock bounce_map_list_spin =
 172         SPINLOCK_INITIALIZER(&bounce_map_list_spin);
 173
 174 static struct bus_dmamap nobounce_dmamap;
 175
 176 static int              alloc_bounce_zone(bus_dma_tag_t);
 177 static int              alloc_bounce_pages(bus_dma_tag_t, u_int, int);
 178 static void             free_bounce_pages_all(bus_dma_tag_t);
 179 static void             free_bounce_zone(bus_dma_tag_t);
 180 static int              reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
 181 static void             return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
 182 static bus_addr_t       add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
 183                             vm_offset_t, bus_size_t);
 184 static void             free_bounce_page(bus_dma_tag_t, struct bounce_page *);
 185
 186 static bus_dmamap_t     get_map_waiting(bus_dma_tag_t);
 187 static void             add_map_callback(bus_dmamap_t);
 188
 189 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 190 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
 191            0, "Total bounce pages");
 192 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
 193            0, "Max bounce pages per bounce zone");
 194 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
 195            &bounce_alignment, 0, "Obey alignment constraint");
 196
 197 static __inline int
 198 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 199 {
 200         int retval;
 201
 202         retval = 0;
 203         do {
 204                 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
 205                      (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
 206                  && (dmat->filter == NULL ||
 207                      dmat->filter(dmat->filterarg, paddr) != 0))
 208                         retval = 1;
 209
 210                 dmat = dmat->parent;
 211         } while (retval == 0 && dmat != NULL);
 212         return (retval);
 213 }
 214
 215 static __inline
 216 bus_dma_segment_t *
 217 bus_dma_tag_lock(bus_dma_tag_t tag, bus_dma_segment_t *cache)
 218 {
 219         if (tag->flags & BUS_DMA_PROTECTED)
 220                 return(tag->segments);
 221
 222         if (tag->nsegments <= BUS_DMA_CACHE_SEGMENTS)
 223                 return(cache);
 224 #ifdef SMP
 225         spin_lock(&tag->spin);
 226 #endif
 227         return(tag->segments);
 228 }
 229
 230 static __inline
 231 void
 232 bus_dma_tag_unlock(bus_dma_tag_t tag)
 233 {
 234 #ifdef SMP
 235         if (tag->flags & BUS_DMA_PROTECTED)
 236                 return;
 237
 238         if (tag->nsegments > BUS_DMA_CACHE_SEGMENTS)
 239                 spin_unlock(&tag->spin);
 240 #endif
 241 }
 242
 243 /*
 244  * Allocate a device specific dma_tag.
 245  */
 246 int
 247 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 248                    bus_size_t boundary, bus_addr_t lowaddr,
 249                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 250                    void *filterarg, bus_size_t maxsize, int nsegments,
 251                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 252 {
 253         bus_dma_tag_t newtag;
 254         int error = 0;
 255
 256         /*
 257          * Sanity checks
 258          */
 259
 260         if (alignment == 0)
 261                 alignment = 1;
 262         if (alignment & (alignment - 1))
 263                 panic("alignment must be power of 2\n");
 264
 265         if (boundary != 0) {
 266                 if (boundary & (boundary - 1))
 267                         panic("boundary must be power of 2\n");
 268                 if (boundary < maxsegsz) {
 269                         kprintf("boundary < maxsegsz:\n");
 270                         print_backtrace(-1);
 271                         maxsegsz = boundary;
 272                 }
 273         }
 274
 275         /* Return a NULL tag on failure */
 276         *dmat = NULL;
 277
 278         newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT | M_ZERO);
 279
 280 #ifdef SMP
 281         spin_init(&newtag->spin);
 282 #endif
 283         newtag->parent = parent;
 284         newtag->alignment = alignment;
 285         newtag->boundary = boundary;
 286         newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 287         newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
 288         newtag->filter = filter;
 289         newtag->filterarg = filterarg;
 290         newtag->maxsize = maxsize;
 291         newtag->nsegments = nsegments;
 292         newtag->maxsegsz = maxsegsz;
 293         newtag->flags = flags;
 294         newtag->ref_count = 1; /* Count ourself */
 295         newtag->map_count = 0;
 296         newtag->segments = NULL;
 297         newtag->bounce_zone = NULL;
 298
 299         /* Take into account any restrictions imposed by our parent tag */
 300         if (parent != NULL) {
 301                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 302                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 303
 304                 if (newtag->boundary == 0) {
 305                         newtag->boundary = parent->boundary;
 306                 } else if (parent->boundary != 0) {
 307                         newtag->boundary = MIN(parent->boundary,
 308                                                newtag->boundary);
 309                 }
 310
 311 #ifdef notyet
 312                 newtag->alignment = MAX(parent->alignment, newtag->alignment);
 313 #endif
 314
 315                 if (newtag->filter == NULL) {
 316                         /*
 317                          * Short circuit looking at our parent directly
 318                          * since we have encapsulated all of its information
 319                          */
 320                         newtag->filter = parent->filter;
 321                         newtag->filterarg = parent->filterarg;
 322                         newtag->parent = parent->parent;
 323                 }
 324                 if (newtag->parent != NULL)
 325                         parent->ref_count++;
 326         }
 327
 328         if (newtag->lowaddr < ptoa(Maxmem))
 329                 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
 330         if (bounce_alignment && newtag->alignment > 1 &&
 331             !(newtag->flags & BUS_DMA_ALIGNED))
 332                 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
 333
 334         if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
 335             (flags & BUS_DMA_ALLOCNOW) != 0) {
 336                 struct bounce_zone *bz;
 337
 338                 /* Must bounce */
 339
 340                 error = alloc_bounce_zone(newtag);
 341                 if (error)
 342                         goto back;
 343                 bz = newtag->bounce_zone;
 344
 345                 if ((newtag->flags & BUS_DMA_ALLOCALL) == 0 &&
 346                     ptoa(bz->total_bpages) < maxsize) {
 347                         int pages;
 348
 349                         if (flags & BUS_DMA_ONEBPAGE) {
 350                                 pages = 1;
 351                         } else {
 352                                 pages = atop(round_page(maxsize)) -
 353                                         bz->total_bpages;
 354                                 pages = MAX(pages, 1);
 355                         }
 356
 357                         /* Add pages to our bounce pool */
 358                         if (alloc_bounce_pages(newtag, pages, flags) < pages)
 359                                 error = ENOMEM;
 360
 361                         /* Performed initial allocation */
 362                         newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 363                 }
 364         }
 365 back:
 366         if (error) {
 367                 free_bounce_zone(newtag);
 368                 kfree(newtag, M_DEVBUF);
 369         } else {
 370                 *dmat = newtag;
 371         }
 372         return error;
 373 }
 374
 375 int
 376 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 377 {
 378         if (dmat != NULL) {
 379                 if (dmat->map_count != 0)
 380                         return (EBUSY);
 381
 382                 while (dmat != NULL) {
 383                         bus_dma_tag_t parent;
 384
 385                         parent = dmat->parent;
 386                         dmat->ref_count--;
 387                         if (dmat->ref_count == 0) {
 388                                 free_bounce_zone(dmat);
 389                                 if (dmat->segments != NULL)
 390                                         kfree(dmat->segments, M_DEVBUF);
 391                                 kfree(dmat, M_DEVBUF);
 392                                 /*
 393                                  * Last reference count, so
 394                                  * release our reference
 395                                  * count on our parent.
 396                                  */
 397                                 dmat = parent;
 398                         } else
 399                                 dmat = NULL;
 400                 }
 401         }
 402         return (0);
 403 }
 404
 405 bus_size_t
 406 bus_dma_tag_getmaxsize(bus_dma_tag_t tag)
 407 {
 408         return(tag->maxsize);
 409 }
 410
 411 /*
 412  * Allocate a handle for mapping from kva/uva/physical
 413  * address space into bus device space.
 414  */
 415 int
 416 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 417 {
 418         int error;
 419
 420         error = 0;
 421
 422         if (dmat->segments == NULL) {
 423                 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
 424                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 425                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 426         }
 427
 428         if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
 429                 struct bounce_zone *bz;
 430                 int maxpages;
 431
 432                 /* Must bounce */
 433
 434                 if (dmat->bounce_zone == NULL) {
 435                         error = alloc_bounce_zone(dmat);
 436                         if (error)
 437                                 return error;
 438                 }
 439                 bz = dmat->bounce_zone;
 440
 441                 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
 442
 443                 /* Initialize the new map */
 444                 STAILQ_INIT(&((*mapp)->bpages));
 445
 446                 /*
 447                  * Attempt to add pages to our pool on a per-instance
 448                  * basis up to a sane limit.
 449                  */
 450                 if (dmat->flags & BUS_DMA_ALLOCALL) {
 451                         maxpages = Maxmem - atop(dmat->lowaddr);
 452                 } else if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
 453                         maxpages = max_bounce_pages;
 454                 } else {
 455                         maxpages = MIN(max_bounce_pages,
 456                                        Maxmem - atop(dmat->lowaddr));
 457                 }
 458                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 459                     (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
 460                         int pages;
 461
 462                         if (flags & BUS_DMA_ONEBPAGE) {
 463                                 pages = 1;
 464                         } else {
 465                                 pages = atop(round_page(dmat->maxsize));
 466                                 pages = MIN(maxpages - bz->total_bpages, pages);
 467                                 pages = MAX(pages, 1);
 468                         }
 469                         if (alloc_bounce_pages(dmat, pages, flags) < pages)
 470                                 error = ENOMEM;
 471
 472                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 473                                 if (!error &&
 474                                     (dmat->flags & BUS_DMA_ALLOCALL) == 0)
 475                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 476                         } else {
 477                                 error = 0;
 478                         }
 479                 }
 480         } else {
 481                 *mapp = NULL;
 482         }
 483         if (!error) {
 484                 dmat->map_count++;
 485         } else {
 486                 kfree(*mapp, M_DEVBUF);
 487                 *mapp = NULL;
 488         }
 489         return error;
 490 }
 491
 492 /*
 493  * Destroy a handle for mapping from kva/uva/physical
 494  * address space into bus device space.
 495  */
 496 int
 497 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 498 {
 499         if (map != NULL) {
 500                 if (STAILQ_FIRST(&map->bpages) != NULL)
 501                         return (EBUSY);
 502                 kfree(map, M_DEVBUF);
 503         }
 504         dmat->map_count--;
 505         return (0);
 506 }
 507
 508 static __inline bus_size_t
 509 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
 510 {
 511         bus_size_t maxsize = 0;
 512         uintptr_t vaddr = (uintptr_t)vaddr0;
 513
 514         if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
 515                 if (verify || bootverbose)
 516                         kprintf("boundary check failed\n");
 517                 if (verify)
 518                         print_backtrace(-1); /* XXX panic */
 519                 maxsize = dmat->maxsize;
 520         }
 521         if (vaddr & (dmat->alignment - 1)) {
 522                 if (verify || bootverbose)
 523                         kprintf("alignment check failed\n");
 524                 if (verify)
 525                         print_backtrace(-1); /* XXX panic */
 526                 if (dmat->maxsize < dmat->alignment)
 527                         maxsize = dmat->alignment;
 528                 else
 529                         maxsize = dmat->maxsize;
 530         }
 531         return maxsize;
 532 }
 533
 534 /*
 535  * Allocate a piece of memory that can be efficiently mapped into
 536  * bus device space based on the constraints lited in the dma tag.
 537  *
 538  * mapp is degenerate.  By definition this allocation should not require
 539  * bounce buffers so do not allocate a dma map.
 540  */
 541 int
 542 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
 543                  bus_dmamap_t *mapp)
 544 {
 545         int mflags;
 546
 547         /* If we succeed, no mapping/bouncing will be required */
 548         *mapp = NULL;
 549
 550         if (dmat->segments == NULL) {
 551                 KKASSERT(dmat->nsegments < 16384);
 552                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 553                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 554         }
 555
 556         if (flags & BUS_DMA_NOWAIT)
 557                 mflags = M_NOWAIT;
 558         else
 559                 mflags = M_WAITOK;
 560         if (flags & BUS_DMA_ZERO)
 561                 mflags |= M_ZERO;
 562
 563         if (BUS_DMAMEM_KMALLOC(dmat)) {
 564                 bus_size_t maxsize;
 565
 566                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 567
 568                 /*
 569                  * XXX
 570                  * Check whether the allocation
 571                  * - crossed a page boundary
 572                  * - was not aligned
 573                  * Retry with power-of-2 alignment in the above cases.
 574                  */
 575                 maxsize = check_kmalloc(dmat, *vaddr, 0);
 576                 if (maxsize) {
 577                         size_t size;
 578
 579                         kfree(*vaddr, M_DEVBUF);
 580                         /* XXX check for overflow? */
 581                         for (size = 1; size <= maxsize; size <<= 1)
 582                                 ;
 583                         *vaddr = kmalloc(size, M_DEVBUF, mflags);
 584                         check_kmalloc(dmat, *vaddr, 1);
 585                 }
 586         } else {
 587                 /*
 588                  * XXX Use Contigmalloc until it is merged into this facility
 589                  *     and handles multi-seg allocations.  Nobody is doing
 590                  *     multi-seg allocations yet though.
 591                  */
 592                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 593                     0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
 594         }
 595         if (*vaddr == NULL)
 596                 return (ENOMEM);
 597         return (0);
 598 }
 599
 600 /*
 601  * Free a piece of memory and it's allociated dmamap, that was allocated
 602  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 603  */
 604 void
 605 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 606 {
 607         /*
 608          * dmamem does not need to be bounced, so the map should be
 609          * NULL
 610          */
 611         if (map != NULL)
 612                 panic("bus_dmamem_free: Invalid map freed\n");
 613         if (BUS_DMAMEM_KMALLOC(dmat))
 614                 kfree(vaddr, M_DEVBUF);
 615         else
 616                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 617 }
 618
 619 static __inline vm_paddr_t
 620 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
 621 {
 622         if (pmap)
 623                 return pmap_extract(pmap, vaddr);
 624         else
 625                 return pmap_kextract(vaddr);
 626 }
 627
 628 /*
 629  * Utility function to load a linear buffer.  lastaddrp holds state
 630  * between invocations (for multiple-buffer loads).  segp contains
 631  * the segment following the starting one on entrace, and the ending
 632  * segment on exit.  first indicates if this is the first invocation
 633  * of this function.
 634  */
 635 static int
 636 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 637                         bus_dmamap_t map,
 638                         void *buf, bus_size_t buflen,
 639                         bus_dma_segment_t *segments,
 640                         int nsegments,
 641                         pmap_t pmap,
 642                         int flags,
 643                         vm_paddr_t *lastpaddrp,
 644                         int *segp,
 645                         int first)
 646 {
 647         vm_offset_t vaddr;
 648         vm_paddr_t paddr, nextpaddr;
 649         bus_dma_segment_t *sg;
 650         bus_addr_t bmask;
 651         int seg, error = 0;
 652
 653         if (map == NULL)
 654                 map = &nobounce_dmamap;
 655
 656 #ifdef INVARIANTS
 657         if (dmat->flags & BUS_DMA_ALIGNED)
 658                 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
 659 #endif
 660
 661         /*
 662          * If we are being called during a callback, pagesneeded will
 663          * be non-zero, so we can avoid doing the work twice.
 664          */
 665         if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 666             map != &nobounce_dmamap && map->pagesneeded == 0) {
 667                 vm_offset_t vendaddr;
 668
 669                 /*
 670                  * Count the number of bounce pages
 671                  * needed in order to complete this transfer
 672                  */
 673                 vaddr = (vm_offset_t)buf;
 674                 vendaddr = (vm_offset_t)buf + buflen;
 675
 676                 while (vaddr < vendaddr) {
 677                         paddr = _bus_dma_extract(pmap, vaddr);
 678                         if (run_filter(dmat, paddr) != 0)
 679                                 map->pagesneeded++;
 680                         vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
 681                 }
 682         }
 683
 684         /* Reserve Necessary Bounce Pages */
 685         if (map->pagesneeded != 0) {
 686                 struct bounce_zone *bz;
 687
 688                 bz = dmat->bounce_zone;
 689                 BZ_LOCK(bz);
 690                 if (flags & BUS_DMA_NOWAIT) {
 691                         if (reserve_bounce_pages(dmat, map, 0) != 0) {
 692                                 BZ_UNLOCK(bz);
 693                                 error = ENOMEM;
 694                                 goto free_bounce;
 695                         }
 696                 } else {
 697                         if (reserve_bounce_pages(dmat, map, 1) != 0) {
 698                                 /* Queue us for resources */
 699                                 map->dmat = dmat;
 700                                 map->buf = buf;
 701                                 map->buflen = buflen;
 702
 703                                 STAILQ_INSERT_TAIL(
 704                                     &dmat->bounce_zone->bounce_map_waitinglist,
 705                                     map, links);
 706                                 BZ_UNLOCK(bz);
 707
 708                                 return (EINPROGRESS);
 709                         }
 710                 }
 711                 BZ_UNLOCK(bz);
 712         }
 713
 714         KKASSERT(*segp >= 1 && *segp <= nsegments);
 715         seg = *segp;
 716         sg = &segments[seg - 1];
 717
 718         vaddr = (vm_offset_t)buf;
 719         nextpaddr = *lastpaddrp;
 720         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 721
 722         /* force at least one segment */
 723         do {
 724                 bus_size_t size;
 725
 726                 /*
 727                  * Per-page main loop
 728                  */
 729                 paddr = _bus_dma_extract(pmap, vaddr);
 730                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 731                 if (size > buflen)
 732                         size = buflen;
 733                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 734                         /*
 735                          * note: this paddr has the same in-page offset
 736                          * as vaddr and thus the paddr above, so the
 737                          * size does not have to be recalculated
 738                          */
 739                         paddr = add_bounce_page(dmat, map, vaddr, size);
 740                 }
 741
 742                 /*
 743                  * Fill in the bus_dma_segment
 744                  */
 745                 if (first) {
 746                         sg->ds_addr = paddr;
 747                         sg->ds_len = size;
 748                         first = 0;
 749                 } else if (paddr == nextpaddr) {
 750                         sg->ds_len += size;
 751                 } else {
 752                         sg++;
 753                         seg++;
 754                         if (seg > nsegments)
 755                                 break;
 756                         sg->ds_addr = paddr;
 757                         sg->ds_len = size;
 758                 }
 759                 nextpaddr = paddr + size;
 760
 761                 /*
 762                  * Handle maxsegsz and boundary issues with a nested loop
 763                  */
 764                 for (;;) {
 765                         bus_size_t tmpsize;
 766
 767                         /*
 768                          * Limit to the boundary and maximum segment size
 769                          */
 770                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 771                                 tmpsize = dmat->boundary -
 772                                           (sg->ds_addr & ~bmask);
 773                                 if (tmpsize > dmat->maxsegsz)
 774                                         tmpsize = dmat->maxsegsz;
 775                                 KKASSERT(tmpsize < sg->ds_len);
 776                         } else if (sg->ds_len > dmat->maxsegsz) {
 777                                 tmpsize = dmat->maxsegsz;
 778                         } else {
 779                                 break;
 780                         }
 781
 782                         /*
 783                          * Futz, split the data into a new segment.
 784                          */
 785                         if (seg >= nsegments)
 786                                 goto fail;
 787                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 788                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 789                         sg[0].ds_len = tmpsize;
 790                         sg++;
 791                         seg++;
 792                 }
 793
 794                 /*
 795                  * Adjust for loop
 796                  */
 797                 buflen -= size;
 798                 vaddr += size;
 799         } while (buflen > 0);
 800 fail:
 801         if (buflen != 0)
 802                 error = EFBIG;
 803
 804         *segp = seg;
 805         *lastpaddrp = nextpaddr;
 806
 807 free_bounce:
 808         if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 809             map != &nobounce_dmamap) {
 810                 _bus_dmamap_unload(dmat, map);
 811                 return_bounce_pages(dmat, map);
 812         }
 813         return error;
 814 }
 815
 816 /*
 817  * Map the buffer buf into bus space using the dmamap map.
 818  */
 819 int
 820 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 821                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 822                 void *callback_arg, int flags)
 823 {
 824         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 825         bus_dma_segment_t *segments;
 826         vm_paddr_t lastaddr = 0;
 827         int error, nsegs = 1;
 828
 829         if (map != NULL) {
 830                 /*
 831                  * XXX
 832                  * Follow old semantics.  Once all of the callers are fixed,
 833                  * we should get rid of these internal flag "adjustment".
 834                  */
 835                 flags &= ~BUS_DMA_NOWAIT;
 836                 flags |= BUS_DMA_WAITOK;
 837
 838                 map->callback = callback;
 839                 map->callback_arg = callback_arg;
 840         }
 841
 842         segments = bus_dma_tag_lock(dmat, cache_segments);
 843         error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
 844                         segments, dmat->nsegments,
 845                         NULL, flags, &lastaddr, &nsegs, 1);
 846         if (error == EINPROGRESS) {
 847                 KKASSERT((dmat->flags &
 848                           (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL)) !=
 849                          (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL));
 850
 851                 if (dmat->flags & BUS_DMA_PROTECTED)
 852                         panic("protected dmamap callback will be defered\n");
 853
 854                 bus_dma_tag_unlock(dmat);
 855                 return error;
 856         }
 857         callback(callback_arg, segments, nsegs, error);
 858         bus_dma_tag_unlock(dmat);
 859         return 0;
 860 }
 861
 862 /*
 863  * Like _bus_dmamap_load(), but for mbufs.
 864  */
 865 int
 866 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 867                      struct mbuf *m0,
 868                      bus_dmamap_callback2_t *callback, void *callback_arg,
 869                      int flags)
 870 {
 871         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 872         bus_dma_segment_t *segments;
 873         int nsegs, error;
 874
 875         /*
 876          * XXX
 877          * Follow old semantics.  Once all of the callers are fixed,
 878          * we should get rid of these internal flag "adjustment".
 879          */
 880         flags &= ~BUS_DMA_WAITOK;
 881         flags |= BUS_DMA_NOWAIT;
 882
 883         segments = bus_dma_tag_lock(dmat, cache_segments);
 884         error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
 885                         segments, dmat->nsegments, &nsegs, flags);
 886         if (error) {
 887                 /* force "no valid mappings" in callback */
 888                 callback(callback_arg, segments, 0,
 889                          0, error);
 890         } else {
 891                 callback(callback_arg, segments, nsegs,
 892                          m0->m_pkthdr.len, error);
 893         }
 894         bus_dma_tag_unlock(dmat);
 895         return error;
 896 }
 897
 898 int
 899 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
 900                              struct mbuf *m0,
 901                              bus_dma_segment_t *segs, int maxsegs,
 902                              int *nsegs, int flags)
 903 {
 904         int error;
 905
 906         M_ASSERTPKTHDR(m0);
 907
 908         KASSERT(maxsegs >= 1, ("invalid maxsegs %d\n", maxsegs));
 909         KASSERT(maxsegs <= dmat->nsegments,
 910                 ("%d too many segments, dmat only support %d segments\n",
 911                  maxsegs, dmat->nsegments));
 912         KASSERT(flags & BUS_DMA_NOWAIT,
 913                 ("only BUS_DMA_NOWAIT is supported\n"));
 914
 915         if (m0->m_pkthdr.len <= dmat->maxsize) {
 916                 int first = 1;
 917                 vm_paddr_t lastaddr = 0;
 918                 struct mbuf *m;
 919
 920                 *nsegs = 1;
 921                 error = 0;
 922                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 923                         if (m->m_len == 0)
 924                                 continue;
 925
 926                         error = _bus_dmamap_load_buffer(dmat, map,
 927                                         m->m_data, m->m_len,
 928                                         segs, maxsegs,
 929                                         NULL, flags, &lastaddr,
 930                                         nsegs, first);
 931                         if (error == ENOMEM && !first) {
 932                                 /*
 933                                  * Out of bounce pages due to too many
 934                                  * fragments in the mbuf chain; return
 935                                  * EFBIG instead.
 936                                  */
 937                                 error = EFBIG;
 938                         }
 939                         first = 0;
 940                 }
 941 #ifdef INVARIANTS
 942                 if (!error)
 943                         KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
 944 #endif
 945         } else {
 946                 *nsegs = 0;
 947                 error = EINVAL;
 948         }
 949         KKASSERT(error != EINPROGRESS);
 950         return error;
 951 }
 952
 953 /*
 954  * Like _bus_dmamap_load(), but for uios.
 955  */
 956 int
 957 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 958                     struct uio *uio,
 959                     bus_dmamap_callback2_t *callback, void *callback_arg,
 960                     int flags)
 961 {
 962         vm_paddr_t lastaddr;
 963         int nsegs, error, first, i;
 964         bus_size_t resid;
 965         struct iovec *iov;
 966         pmap_t pmap;
 967         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 968         bus_dma_segment_t *segments;
 969         bus_dma_segment_t *segs;
 970         int nsegs_left;
 971
 972         if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS)
 973                 segments = cache_segments;
 974         else
 975                 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments,
 976                                    M_DEVBUF, M_WAITOK | M_ZERO);
 977
 978         /*
 979          * XXX
 980          * Follow old semantics.  Once all of the callers are fixed,
 981          * we should get rid of these internal flag "adjustment".
 982          */
 983         flags &= ~BUS_DMA_WAITOK;
 984         flags |= BUS_DMA_NOWAIT;
 985
 986         resid = (bus_size_t)uio->uio_resid;
 987         iov = uio->uio_iov;
 988
 989         segs = segments;
 990         nsegs_left = dmat->nsegments;
 991
 992         if (uio->uio_segflg == UIO_USERSPACE) {
 993                 struct thread *td;
 994
 995                 td = uio->uio_td;
 996                 KASSERT(td != NULL && td->td_proc != NULL,
 997                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 998                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 999         } else {
1000                 pmap = NULL;
1001         }
1002
1003         error = 0;
1004         nsegs = 1;
1005         first = 1;
1006         lastaddr = 0;
1007         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
1008                 /*
1009                  * Now at the first iovec to load.  Load each iovec
1010                  * until we have exhausted the residual count.
1011                  */
1012                 bus_size_t minlen =
1013                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
1014                 caddr_t addr = (caddr_t) iov[i].iov_base;
1015
1016                 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
1017                                 segs, nsegs_left,
1018                                 pmap, flags, &lastaddr, &nsegs, first);
1019                 first = 0;
1020
1021                 resid -= minlen;
1022                 if (error == 0) {
1023                         nsegs_left -= nsegs;
1024                         segs += nsegs;
1025                 }
1026         }
1027
1028         /*
1029          * Minimum one DMA segment, even if 0-length buffer.
1030          */
1031         if (nsegs_left == dmat->nsegments)
1032                 --nsegs_left;
1033
1034         if (error) {
1035                 /* force "no valid mappings" in callback */
1036                 callback(callback_arg, segments, 0,
1037                          0, error);
1038         } else {
1039                 callback(callback_arg, segments, dmat->nsegments - nsegs_left,
1040                          (bus_size_t)uio->uio_resid, error);
1041         }
1042         if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS)
1043                 kfree(segments, M_DEVBUF);
1044         return error;
1045 }
1046
1047 /*
1048  * Release the mapping held by map.
1049  */
1050 void
1051 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1052 {
1053         struct bounce_page *bpage;
1054
1055         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1056                 STAILQ_REMOVE_HEAD(&map->bpages, links);
1057                 free_bounce_page(dmat, bpage);
1058         }
1059 }
1060
1061 void
1062 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1063 {
1064         struct bounce_page *bpage;
1065
1066         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1067                 /*
1068                  * Handle data bouncing.  We might also
1069                  * want to add support for invalidating
1070                  * the caches on broken hardware
1071                  */
1072                 switch (op) {
1073                 case BUS_DMASYNC_PREWRITE:
1074                         while (bpage != NULL) {
1075                                 bcopy((void *)bpage->datavaddr,
1076                                       (void *)bpage->vaddr,
1077                                       bpage->datacount);
1078                                 bpage = STAILQ_NEXT(bpage, links);
1079                         }
1080                         dmat->bounce_zone->total_bounced++;
1081                         break;
1082
1083                 case BUS_DMASYNC_POSTREAD:
1084                         while (bpage != NULL) {
1085                                 bcopy((void *)bpage->vaddr,
1086                                       (void *)bpage->datavaddr,
1087                                       bpage->datacount);
1088                                 bpage = STAILQ_NEXT(bpage, links);
1089                         }
1090                         dmat->bounce_zone->total_bounced++;
1091                         break;
1092
1093                 case BUS_DMASYNC_PREREAD:
1094                 case BUS_DMASYNC_POSTWRITE:
1095                         /* No-ops */
1096                         break;
1097                 }
1098         }
1099 }
1100
1101 static int
1102 alloc_bounce_zone(bus_dma_tag_t dmat)
1103 {
1104         struct bounce_zone *bz, *new_bz;
1105
1106         KASSERT(dmat->bounce_zone == NULL,
1107                 ("bounce zone was already assigned\n"));
1108
1109         new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1110
1111         lwkt_gettoken(&bounce_zone_tok);
1112
1113         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1114                 /*
1115                  * For shared bounce zone, check to see
1116                  * if we already have a suitable zone
1117                  */
1118                 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1119                         if (dmat->alignment <= bz->alignment &&
1120                             dmat->lowaddr >= bz->lowaddr) {
1121                                 lwkt_reltoken(&bounce_zone_tok);
1122
1123                                 dmat->bounce_zone = bz;
1124                                 kfree(new_bz, M_DEVBUF);
1125                                 return 0;
1126                         }
1127                 }
1128         }
1129         bz = new_bz;
1130
1131 #ifdef SMP
1132         spin_init(&bz->spin);
1133 #endif
1134         STAILQ_INIT(&bz->bounce_page_list);
1135         STAILQ_INIT(&bz->bounce_map_waitinglist);
1136         bz->free_bpages = 0;
1137         bz->reserved_bpages = 0;
1138         bz->active_bpages = 0;
1139         bz->lowaddr = dmat->lowaddr;
1140         bz->alignment = round_page(dmat->alignment);
1141         ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1142
1143         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1144                 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1145                 busdma_zonecount++;
1146                 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1147         } else {
1148                 ksnprintf(bz->zoneid, 8, "zone%d", busdma_priv_zonecount);
1149                 busdma_priv_zonecount--;
1150         }
1151
1152         lwkt_reltoken(&bounce_zone_tok);
1153
1154         dmat->bounce_zone = bz;
1155
1156         sysctl_ctx_init(&bz->sysctl_ctx);
1157         bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1158             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1159             CTLFLAG_RD, 0, "");
1160         if (bz->sysctl_tree == NULL) {
1161                 sysctl_ctx_free(&bz->sysctl_ctx);
1162                 return 0;       /* XXX error code? */
1163         }
1164
1165         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1166             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1167             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1168             "Total bounce pages");
1169         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1170             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1171             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1172             "Free bounce pages");
1173         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1174             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1175             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1176             "Reserved bounce pages");
1177         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1178             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1179             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1180             "Active bounce pages");
1181         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1182             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1183             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1184             "Total bounce requests");
1185         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1186             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1187             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1188             "Total bounce requests that were deferred");
1189         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1190             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1191             "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1192             "Total bounce page reservations that were failed");
1193         SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1194             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1195             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1196         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1197             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1198             "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1199
1200         return 0;
1201 }
1202
1203 static int
1204 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1205 {
1206         struct bounce_zone *bz = dmat->bounce_zone;
1207         int count = 0, mflags;
1208
1209         if (flags & BUS_DMA_NOWAIT)
1210                 mflags = M_NOWAIT;
1211         else
1212                 mflags = M_WAITOK;
1213
1214         while (numpages > 0) {
1215                 struct bounce_page *bpage;
1216
1217                 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1218
1219                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1220                                                          mflags, 0ul,
1221                                                          bz->lowaddr,
1222                                                          bz->alignment, 0);
1223                 if (bpage->vaddr == 0) {
1224                         kfree(bpage, M_DEVBUF);
1225                         break;
1226                 }
1227                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1228
1229                 BZ_LOCK(bz);
1230                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1231                 total_bounce_pages++;
1232                 bz->total_bpages++;
1233                 bz->free_bpages++;
1234                 BZ_UNLOCK(bz);
1235
1236                 count++;
1237                 numpages--;
1238         }
1239         return count;
1240 }
1241
1242 static void
1243 free_bounce_pages_all(bus_dma_tag_t dmat)
1244 {
1245         struct bounce_zone *bz = dmat->bounce_zone;
1246         struct bounce_page *bpage;
1247
1248         BZ_LOCK(bz);
1249
1250         while ((bpage = STAILQ_FIRST(&bz->bounce_page_list)) != NULL) {
1251                 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1252
1253                 KKASSERT(total_bounce_pages > 0);
1254                 total_bounce_pages--;
1255
1256                 KKASSERT(bz->total_bpages > 0);
1257                 bz->total_bpages--;
1258
1259                 KKASSERT(bz->free_bpages > 0);
1260                 bz->free_bpages--;
1261
1262                 contigfree((void *)bpage->vaddr, PAGE_SIZE, M_DEVBUF);
1263                 kfree(bpage, M_DEVBUF);
1264         }
1265         if (bz->total_bpages) {
1266                 kprintf("#%d bounce pages are still in use\n",
1267                         bz->total_bpages);
1268                 print_backtrace(-1);
1269         }
1270
1271         BZ_UNLOCK(bz);
1272 }
1273
1274 static void
1275 free_bounce_zone(bus_dma_tag_t dmat)
1276 {
1277         struct bounce_zone *bz = dmat->bounce_zone;
1278
1279         if (bz == NULL)
1280                 return;
1281
1282         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0)
1283                 return;
1284
1285         free_bounce_pages_all(dmat);
1286         dmat->bounce_zone = NULL;
1287
1288         if (bz->sysctl_tree != NULL)
1289                 sysctl_ctx_free(&bz->sysctl_ctx);
1290         kfree(bz, M_DEVBUF);
1291 }
1292
1293 /* Assume caller holds bounce zone spinlock */
1294 static int
1295 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1296 {
1297         struct bounce_zone *bz = dmat->bounce_zone;
1298         int pages;
1299
1300         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1301         if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1302                 bz->reserve_failed++;
1303                 return (map->pagesneeded - (map->pagesreserved + pages));
1304         }
1305
1306         bz->free_bpages -= pages;
1307
1308         bz->reserved_bpages += pages;
1309         KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1310
1311         map->pagesreserved += pages;
1312         pages = map->pagesneeded - map->pagesreserved;
1313
1314         return pages;
1315 }
1316
1317 static void
1318 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1319 {
1320         struct bounce_zone *bz = dmat->bounce_zone;
1321         int reserved = map->pagesreserved;
1322         bus_dmamap_t wait_map;
1323
1324         map->pagesreserved = 0;
1325         map->pagesneeded = 0;
1326
1327         if (reserved == 0)
1328                 return;
1329
1330         BZ_LOCK(bz);
1331
1332         bz->free_bpages += reserved;
1333         KKASSERT(bz->free_bpages <= bz->total_bpages);
1334
1335         KKASSERT(bz->reserved_bpages >= reserved);
1336         bz->reserved_bpages -= reserved;
1337
1338         wait_map = get_map_waiting(dmat);
1339
1340         BZ_UNLOCK(bz);
1341
1342         if (wait_map != NULL)
1343                 add_map_callback(map);
1344 }
1345
1346 static bus_addr_t
1347 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1348                 bus_size_t size)
1349 {
1350         struct bounce_zone *bz = dmat->bounce_zone;
1351         struct bounce_page *bpage;
1352
1353         KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1354         map->pagesneeded--;
1355
1356         KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1357         map->pagesreserved--;
1358
1359         BZ_LOCK(bz);
1360
1361         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1362         KASSERT(bpage != NULL, ("free page list is empty"));
1363         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1364
1365         KKASSERT(bz->reserved_bpages > 0);
1366         bz->reserved_bpages--;
1367
1368         bz->active_bpages++;
1369         KKASSERT(bz->active_bpages <= bz->total_bpages);
1370
1371         BZ_UNLOCK(bz);
1372
1373         bpage->datavaddr = vaddr;
1374         bpage->datacount = size;
1375         STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1376         return bpage->busaddr;
1377 }
1378
1379 static void
1380 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1381 {
1382         struct bounce_zone *bz = dmat->bounce_zone;
1383         bus_dmamap_t map;
1384
1385         bpage->datavaddr = 0;
1386         bpage->datacount = 0;
1387
1388         BZ_LOCK(bz);
1389
1390         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1391
1392         bz->free_bpages++;
1393         KKASSERT(bz->free_bpages <= bz->total_bpages);
1394
1395         KKASSERT(bz->active_bpages > 0);
1396         bz->active_bpages--;
1397
1398         map = get_map_waiting(dmat);
1399
1400         BZ_UNLOCK(bz);
1401
1402         if (map != NULL)
1403                 add_map_callback(map);
1404 }
1405
1406 /* Assume caller holds bounce zone spinlock */
1407 static bus_dmamap_t
1408 get_map_waiting(bus_dma_tag_t dmat)
1409 {
1410         struct bounce_zone *bz = dmat->bounce_zone;
1411         bus_dmamap_t map;
1412
1413         map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1414         if (map != NULL) {
1415                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1416                         STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1417                         bz->total_deferred++;
1418                 } else {
1419                         map = NULL;
1420                 }
1421         }
1422         return map;
1423 }
1424
1425 static void
1426 add_map_callback(bus_dmamap_t map)
1427 {
1428         spin_lock(&bounce_map_list_spin);
1429         STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1430         busdma_swi_pending = 1;
1431         setsoftvm();
1432         spin_unlock(&bounce_map_list_spin);
1433 }
1434
1435 void
1436 busdma_swi(void)
1437 {
1438         bus_dmamap_t map;
1439
1440         spin_lock(&bounce_map_list_spin);
1441         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1442                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1443                 spin_unlock(&bounce_map_list_spin);
1444                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1445                                 map->callback, map->callback_arg, /*flags*/0);
1446                 spin_lock(&bounce_map_list_spin);
1447         }
1448         spin_unlock(&bounce_map_list_spin);
1449 }