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_MP_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         return error;
 486 }
 487
 488 /*
 489  * Destroy a handle for mapping from kva/uva/physical
 490  * address space into bus device space.
 491  */
 492 int
 493 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 494 {
 495         if (map != NULL) {
 496                 if (STAILQ_FIRST(&map->bpages) != NULL)
 497                         return (EBUSY);
 498                 kfree(map, M_DEVBUF);
 499         }
 500         dmat->map_count--;
 501         return (0);
 502 }
 503
 504 static __inline bus_size_t
 505 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
 506 {
 507         bus_size_t maxsize = 0;
 508         uintptr_t vaddr = (uintptr_t)vaddr0;
 509
 510         if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
 511                 if (verify || bootverbose)
 512                         kprintf("boundary check failed\n");
 513                 if (verify)
 514                         print_backtrace(-1); /* XXX panic */
 515                 maxsize = dmat->maxsize;
 516         }
 517         if (vaddr & (dmat->alignment - 1)) {
 518                 if (verify || bootverbose)
 519                         kprintf("alignment check failed\n");
 520                 if (verify)
 521                         print_backtrace(-1); /* XXX panic */
 522                 if (dmat->maxsize < dmat->alignment)
 523                         maxsize = dmat->alignment;
 524                 else
 525                         maxsize = dmat->maxsize;
 526         }
 527         return maxsize;
 528 }
 529
 530 /*
 531  * Allocate a piece of memory that can be efficiently mapped into
 532  * bus device space based on the constraints lited in the dma tag.
 533  *
 534  * mapp is degenerate.  By definition this allocation should not require
 535  * bounce buffers so do not allocate a dma map.
 536  */
 537 int
 538 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
 539                  bus_dmamap_t *mapp)
 540 {
 541         int mflags;
 542
 543         /* If we succeed, no mapping/bouncing will be required */
 544         *mapp = NULL;
 545
 546         if (dmat->segments == NULL) {
 547                 KKASSERT(dmat->nsegments < 16384);
 548                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 549                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 550         }
 551
 552         if (flags & BUS_DMA_NOWAIT)
 553                 mflags = M_NOWAIT;
 554         else
 555                 mflags = M_WAITOK;
 556         if (flags & BUS_DMA_ZERO)
 557                 mflags |= M_ZERO;
 558
 559         if (BUS_DMAMEM_KMALLOC(dmat)) {
 560                 bus_size_t maxsize;
 561
 562                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 563
 564                 /*
 565                  * XXX
 566                  * Check whether the allocation
 567                  * - crossed a page boundary
 568                  * - was not aligned
 569                  * Retry with power-of-2 alignment in the above cases.
 570                  */
 571                 maxsize = check_kmalloc(dmat, *vaddr, 0);
 572                 if (maxsize) {
 573                         size_t size;
 574
 575                         kfree(*vaddr, M_DEVBUF);
 576                         /* XXX check for overflow? */
 577                         for (size = 1; size <= maxsize; size <<= 1)
 578                                 ;
 579                         *vaddr = kmalloc(size, M_DEVBUF, mflags);
 580                         check_kmalloc(dmat, *vaddr, 1);
 581                 }
 582         } else {
 583                 /*
 584                  * XXX Use Contigmalloc until it is merged into this facility
 585                  *     and handles multi-seg allocations.  Nobody is doing
 586                  *     multi-seg allocations yet though.
 587                  */
 588                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 589                     0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
 590         }
 591         if (*vaddr == NULL)
 592                 return (ENOMEM);
 593         return (0);
 594 }
 595
 596 /*
 597  * Free a piece of memory and it's allociated dmamap, that was allocated
 598  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 599  */
 600 void
 601 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 602 {
 603         /*
 604          * dmamem does not need to be bounced, so the map should be
 605          * NULL
 606          */
 607         if (map != NULL)
 608                 panic("bus_dmamem_free: Invalid map freed\n");
 609         if (BUS_DMAMEM_KMALLOC(dmat))
 610                 kfree(vaddr, M_DEVBUF);
 611         else
 612                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 613 }
 614
 615 static __inline vm_paddr_t
 616 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
 617 {
 618         if (pmap)
 619                 return pmap_extract(pmap, vaddr);
 620         else
 621                 return pmap_kextract(vaddr);
 622 }
 623
 624 /*
 625  * Utility function to load a linear buffer.  lastaddrp holds state
 626  * between invocations (for multiple-buffer loads).  segp contains
 627  * the segment following the starting one on entrace, and the ending
 628  * segment on exit.  first indicates if this is the first invocation
 629  * of this function.
 630  */
 631 static int
 632 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 633                         bus_dmamap_t map,
 634                         void *buf, bus_size_t buflen,
 635                         bus_dma_segment_t *segments,
 636                         int nsegments,
 637                         pmap_t pmap,
 638                         int flags,
 639                         vm_paddr_t *lastpaddrp,
 640                         int *segp,
 641                         int first)
 642 {
 643         vm_offset_t vaddr;
 644         vm_paddr_t paddr, nextpaddr;
 645         bus_dma_segment_t *sg;
 646         bus_addr_t bmask;
 647         int seg, error = 0;
 648
 649         if (map == NULL)
 650                 map = &nobounce_dmamap;
 651
 652 #ifdef INVARIANTS
 653         if (dmat->flags & BUS_DMA_ALIGNED)
 654                 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
 655 #endif
 656
 657         /*
 658          * If we are being called during a callback, pagesneeded will
 659          * be non-zero, so we can avoid doing the work twice.
 660          */
 661         if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 662             map != &nobounce_dmamap && map->pagesneeded == 0) {
 663                 vm_offset_t vendaddr;
 664
 665                 /*
 666                  * Count the number of bounce pages
 667                  * needed in order to complete this transfer
 668                  */
 669                 vaddr = (vm_offset_t)buf;
 670                 vendaddr = (vm_offset_t)buf + buflen;
 671
 672                 while (vaddr < vendaddr) {
 673                         paddr = _bus_dma_extract(pmap, vaddr);
 674                         if (run_filter(dmat, paddr) != 0)
 675                                 map->pagesneeded++;
 676                         vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
 677                 }
 678         }
 679
 680         /* Reserve Necessary Bounce Pages */
 681         if (map->pagesneeded != 0) {
 682                 struct bounce_zone *bz;
 683
 684                 bz = dmat->bounce_zone;
 685                 BZ_LOCK(bz);
 686                 if (flags & BUS_DMA_NOWAIT) {
 687                         if (reserve_bounce_pages(dmat, map, 0) != 0) {
 688                                 BZ_UNLOCK(bz);
 689                                 error = ENOMEM;
 690                                 goto free_bounce;
 691                         }
 692                 } else {
 693                         if (reserve_bounce_pages(dmat, map, 1) != 0) {
 694                                 /* Queue us for resources */
 695                                 map->dmat = dmat;
 696                                 map->buf = buf;
 697                                 map->buflen = buflen;
 698
 699                                 STAILQ_INSERT_TAIL(
 700                                     &dmat->bounce_zone->bounce_map_waitinglist,
 701                                     map, links);
 702                                 BZ_UNLOCK(bz);
 703
 704                                 return (EINPROGRESS);
 705                         }
 706                 }
 707                 BZ_UNLOCK(bz);
 708         }
 709
 710         KKASSERT(*segp >= 1 && *segp <= nsegments);
 711         seg = *segp;
 712         sg = &segments[seg - 1];
 713
 714         vaddr = (vm_offset_t)buf;
 715         nextpaddr = *lastpaddrp;
 716         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 717
 718         /* force at least one segment */
 719         do {
 720                 bus_size_t size;
 721
 722                 /*
 723                  * Per-page main loop
 724                  */
 725                 paddr = _bus_dma_extract(pmap, vaddr);
 726                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 727                 if (size > buflen)
 728                         size = buflen;
 729                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 730                         /*
 731                          * note: this paddr has the same in-page offset
 732                          * as vaddr and thus the paddr above, so the
 733                          * size does not have to be recalculated
 734                          */
 735                         paddr = add_bounce_page(dmat, map, vaddr, size);
 736                 }
 737
 738                 /*
 739                  * Fill in the bus_dma_segment
 740                  */
 741                 if (first) {
 742                         sg->ds_addr = paddr;
 743                         sg->ds_len = size;
 744                         first = 0;
 745                 } else if (paddr == nextpaddr) {
 746                         sg->ds_len += size;
 747                 } else {
 748                         sg++;
 749                         seg++;
 750                         if (seg > nsegments)
 751                                 break;
 752                         sg->ds_addr = paddr;
 753                         sg->ds_len = size;
 754                 }
 755                 nextpaddr = paddr + size;
 756
 757                 /*
 758                  * Handle maxsegsz and boundary issues with a nested loop
 759                  */
 760                 for (;;) {
 761                         bus_size_t tmpsize;
 762
 763                         /*
 764                          * Limit to the boundary and maximum segment size
 765                          */
 766                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 767                                 tmpsize = dmat->boundary -
 768                                           (sg->ds_addr & ~bmask);
 769                                 if (tmpsize > dmat->maxsegsz)
 770                                         tmpsize = dmat->maxsegsz;
 771                                 KKASSERT(tmpsize < sg->ds_len);
 772                         } else if (sg->ds_len > dmat->maxsegsz) {
 773                                 tmpsize = dmat->maxsegsz;
 774                         } else {
 775                                 break;
 776                         }
 777
 778                         /*
 779                          * Futz, split the data into a new segment.
 780                          */
 781                         if (seg >= nsegments)
 782                                 goto fail;
 783                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 784                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 785                         sg[0].ds_len = tmpsize;
 786                         sg++;
 787                         seg++;
 788                 }
 789
 790                 /*
 791                  * Adjust for loop
 792                  */
 793                 buflen -= size;
 794                 vaddr += size;
 795         } while (buflen > 0);
 796 fail:
 797         if (buflen != 0)
 798                 error = EFBIG;
 799
 800         *segp = seg;
 801         *lastpaddrp = nextpaddr;
 802
 803 free_bounce:
 804         if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 805             map != &nobounce_dmamap) {
 806                 _bus_dmamap_unload(dmat, map);
 807                 return_bounce_pages(dmat, map);
 808         }
 809         return error;
 810 }
 811
 812 /*
 813  * Map the buffer buf into bus space using the dmamap map.
 814  */
 815 int
 816 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 817                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 818                 void *callback_arg, int flags)
 819 {
 820         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 821         bus_dma_segment_t *segments;
 822         vm_paddr_t lastaddr = 0;
 823         int error, nsegs = 1;
 824
 825         if (map != NULL) {
 826                 /*
 827                  * XXX
 828                  * Follow old semantics.  Once all of the callers are fixed,
 829                  * we should get rid of these internal flag "adjustment".
 830                  */
 831                 flags &= ~BUS_DMA_NOWAIT;
 832                 flags |= BUS_DMA_WAITOK;
 833
 834                 map->callback = callback;
 835                 map->callback_arg = callback_arg;
 836         }
 837
 838         segments = bus_dma_tag_lock(dmat, cache_segments);
 839         error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
 840                         segments, dmat->nsegments,
 841                         NULL, flags, &lastaddr, &nsegs, 1);
 842         if (error == EINPROGRESS) {
 843                 KKASSERT((dmat->flags &
 844                           (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL)) !=
 845                          (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL));
 846
 847                 if (dmat->flags & BUS_DMA_PROTECTED)
 848                         panic("protected dmamap callback will be defered\n");
 849
 850                 bus_dma_tag_unlock(dmat);
 851                 return error;
 852         }
 853         callback(callback_arg, segments, nsegs, error);
 854         bus_dma_tag_unlock(dmat);
 855         return 0;
 856 }
 857
 858 /*
 859  * Like _bus_dmamap_load(), but for mbufs.
 860  */
 861 int
 862 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 863                      struct mbuf *m0,
 864                      bus_dmamap_callback2_t *callback, void *callback_arg,
 865                      int flags)
 866 {
 867         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 868         bus_dma_segment_t *segments;
 869         int nsegs, error;
 870
 871         /*
 872          * XXX
 873          * Follow old semantics.  Once all of the callers are fixed,
 874          * we should get rid of these internal flag "adjustment".
 875          */
 876         flags &= ~BUS_DMA_WAITOK;
 877         flags |= BUS_DMA_NOWAIT;
 878
 879         segments = bus_dma_tag_lock(dmat, cache_segments);
 880         error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
 881                         segments, dmat->nsegments, &nsegs, flags);
 882         if (error) {
 883                 /* force "no valid mappings" in callback */
 884                 callback(callback_arg, segments, 0,
 885                          0, error);
 886         } else {
 887                 callback(callback_arg, segments, nsegs,
 888                          m0->m_pkthdr.len, error);
 889         }
 890         bus_dma_tag_unlock(dmat);
 891         return error;
 892 }
 893
 894 int
 895 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
 896                              struct mbuf *m0,
 897                              bus_dma_segment_t *segs, int maxsegs,
 898                              int *nsegs, int flags)
 899 {
 900         int error;
 901
 902         M_ASSERTPKTHDR(m0);
 903
 904         KASSERT(maxsegs >= 1, ("invalid maxsegs %d\n", maxsegs));
 905         KASSERT(maxsegs <= dmat->nsegments,
 906                 ("%d too many segments, dmat only support %d segments\n",
 907                  maxsegs, dmat->nsegments));
 908         KASSERT(flags & BUS_DMA_NOWAIT,
 909                 ("only BUS_DMA_NOWAIT is supported\n"));
 910
 911         if (m0->m_pkthdr.len <= dmat->maxsize) {
 912                 int first = 1;
 913                 vm_paddr_t lastaddr = 0;
 914                 struct mbuf *m;
 915
 916                 *nsegs = 1;
 917                 error = 0;
 918                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 919                         if (m->m_len == 0)
 920                                 continue;
 921
 922                         error = _bus_dmamap_load_buffer(dmat, map,
 923                                         m->m_data, m->m_len,
 924                                         segs, maxsegs,
 925                                         NULL, flags, &lastaddr,
 926                                         nsegs, first);
 927                         if (error == ENOMEM && !first) {
 928                                 /*
 929                                  * Out of bounce pages due to too many
 930                                  * fragments in the mbuf chain; return
 931                                  * EFBIG instead.
 932                                  */
 933                                 error = EFBIG;
 934                         }
 935                         first = 0;
 936                 }
 937 #ifdef INVARIANTS
 938                 if (!error)
 939                         KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
 940 #endif
 941         } else {
 942                 *nsegs = 0;
 943                 error = EINVAL;
 944         }
 945         KKASSERT(error != EINPROGRESS);
 946         return error;
 947 }
 948
 949 /*
 950  * Like _bus_dmamap_load(), but for uios.
 951  */
 952 int
 953 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 954                     struct uio *uio,
 955                     bus_dmamap_callback2_t *callback, void *callback_arg,
 956                     int flags)
 957 {
 958         vm_paddr_t lastaddr;
 959         int nsegs, error, first, i;
 960         bus_size_t resid;
 961         struct iovec *iov;
 962         pmap_t pmap;
 963         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 964         bus_dma_segment_t *segments;
 965         bus_dma_segment_t *segs;
 966         int nsegs_left;
 967
 968         if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS)
 969                 segments = cache_segments;
 970         else
 971                 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments,
 972                                    M_DEVBUF, M_WAITOK | M_ZERO);
 973
 974         /*
 975          * XXX
 976          * Follow old semantics.  Once all of the callers are fixed,
 977          * we should get rid of these internal flag "adjustment".
 978          */
 979         flags &= ~BUS_DMA_WAITOK;
 980         flags |= BUS_DMA_NOWAIT;
 981
 982         resid = (bus_size_t)uio->uio_resid;
 983         iov = uio->uio_iov;
 984
 985         segs = segments;
 986         nsegs_left = dmat->nsegments;
 987
 988         if (uio->uio_segflg == UIO_USERSPACE) {
 989                 struct thread *td;
 990
 991                 td = uio->uio_td;
 992                 KASSERT(td != NULL && td->td_proc != NULL,
 993                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 994                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 995         } else {
 996                 pmap = NULL;
 997         }
 998
 999         error = 0;
1000         nsegs = 1;
1001         first = 1;
1002         lastaddr = 0;
1003         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
1004                 /*
1005                  * Now at the first iovec to load.  Load each iovec
1006                  * until we have exhausted the residual count.
1007                  */
1008                 bus_size_t minlen =
1009                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
1010                 caddr_t addr = (caddr_t) iov[i].iov_base;
1011
1012                 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
1013                                 segs, nsegs_left,
1014                                 pmap, flags, &lastaddr, &nsegs, first);
1015                 first = 0;
1016
1017                 resid -= minlen;
1018                 if (error == 0) {
1019                         nsegs_left -= nsegs;
1020                         segs += nsegs;
1021                 }
1022         }
1023
1024         /*
1025          * Minimum one DMA segment, even if 0-length buffer.
1026          */
1027         if (nsegs_left == dmat->nsegments)
1028                 --nsegs_left;
1029
1030         if (error) {
1031                 /* force "no valid mappings" in callback */
1032                 callback(callback_arg, segments, 0,
1033                          0, error);
1034         } else {
1035                 callback(callback_arg, segments, dmat->nsegments - nsegs_left,
1036                          (bus_size_t)uio->uio_resid, error);
1037         }
1038         if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS)
1039                 kfree(segments, M_DEVBUF);
1040         return error;
1041 }
1042
1043 /*
1044  * Release the mapping held by map.
1045  */
1046 void
1047 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1048 {
1049         struct bounce_page *bpage;
1050
1051         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1052                 STAILQ_REMOVE_HEAD(&map->bpages, links);
1053                 free_bounce_page(dmat, bpage);
1054         }
1055 }
1056
1057 void
1058 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1059 {
1060         struct bounce_page *bpage;
1061
1062         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1063                 /*
1064                  * Handle data bouncing.  We might also
1065                  * want to add support for invalidating
1066                  * the caches on broken hardware
1067                  */
1068                 switch (op) {
1069                 case BUS_DMASYNC_PREWRITE:
1070                         while (bpage != NULL) {
1071                                 bcopy((void *)bpage->datavaddr,
1072                                       (void *)bpage->vaddr,
1073                                       bpage->datacount);
1074                                 bpage = STAILQ_NEXT(bpage, links);
1075                         }
1076                         dmat->bounce_zone->total_bounced++;
1077                         break;
1078
1079                 case BUS_DMASYNC_POSTREAD:
1080                         while (bpage != NULL) {
1081                                 bcopy((void *)bpage->vaddr,
1082                                       (void *)bpage->datavaddr,
1083                                       bpage->datacount);
1084                                 bpage = STAILQ_NEXT(bpage, links);
1085                         }
1086                         dmat->bounce_zone->total_bounced++;
1087                         break;
1088
1089                 case BUS_DMASYNC_PREREAD:
1090                 case BUS_DMASYNC_POSTWRITE:
1091                         /* No-ops */
1092                         break;
1093                 }
1094         }
1095 }
1096
1097 static int
1098 alloc_bounce_zone(bus_dma_tag_t dmat)
1099 {
1100         struct bounce_zone *bz, *new_bz;
1101
1102         KASSERT(dmat->bounce_zone == NULL,
1103                 ("bounce zone was already assigned\n"));
1104
1105         new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1106
1107         lwkt_gettoken(&bounce_zone_tok);
1108
1109         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1110                 /*
1111                  * For shared bounce zone, check to see
1112                  * if we already have a suitable zone
1113                  */
1114                 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1115                         if (dmat->alignment <= bz->alignment &&
1116                             dmat->lowaddr >= bz->lowaddr) {
1117                                 lwkt_reltoken(&bounce_zone_tok);
1118
1119                                 dmat->bounce_zone = bz;
1120                                 kfree(new_bz, M_DEVBUF);
1121                                 return 0;
1122                         }
1123                 }
1124         }
1125         bz = new_bz;
1126
1127 #ifdef SMP
1128         spin_init(&bz->spin);
1129 #endif
1130         STAILQ_INIT(&bz->bounce_page_list);
1131         STAILQ_INIT(&bz->bounce_map_waitinglist);
1132         bz->free_bpages = 0;
1133         bz->reserved_bpages = 0;
1134         bz->active_bpages = 0;
1135         bz->lowaddr = dmat->lowaddr;
1136         bz->alignment = round_page(dmat->alignment);
1137         ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1138
1139         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1140                 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1141                 busdma_zonecount++;
1142                 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1143         } else {
1144                 ksnprintf(bz->zoneid, 8, "zone%d", busdma_priv_zonecount);
1145                 busdma_priv_zonecount--;
1146         }
1147
1148         lwkt_reltoken(&bounce_zone_tok);
1149
1150         dmat->bounce_zone = bz;
1151
1152         sysctl_ctx_init(&bz->sysctl_ctx);
1153         bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1154             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1155             CTLFLAG_RD, 0, "");
1156         if (bz->sysctl_tree == NULL) {
1157                 sysctl_ctx_free(&bz->sysctl_ctx);
1158                 return 0;       /* XXX error code? */
1159         }
1160
1161         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1162             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1163             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1164             "Total bounce pages");
1165         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1166             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1167             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1168             "Free bounce pages");
1169         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1170             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1171             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1172             "Reserved bounce pages");
1173         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1174             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1175             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1176             "Active bounce pages");
1177         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1178             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1179             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1180             "Total bounce requests");
1181         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1182             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1183             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1184             "Total bounce requests that were deferred");
1185         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1186             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1187             "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1188             "Total bounce page reservations that were failed");
1189         SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1190             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1191             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1192         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1193             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1194             "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1195
1196         return 0;
1197 }
1198
1199 static int
1200 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1201 {
1202         struct bounce_zone *bz = dmat->bounce_zone;
1203         int count = 0, mflags;
1204
1205         if (flags & BUS_DMA_NOWAIT)
1206                 mflags = M_NOWAIT;
1207         else
1208                 mflags = M_WAITOK;
1209
1210         while (numpages > 0) {
1211                 struct bounce_page *bpage;
1212
1213                 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1214
1215                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1216                                                          mflags, 0ul,
1217                                                          bz->lowaddr,
1218                                                          bz->alignment, 0);
1219                 if (bpage->vaddr == 0) {
1220                         kfree(bpage, M_DEVBUF);
1221                         break;
1222                 }
1223                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1224
1225                 BZ_LOCK(bz);
1226                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1227                 total_bounce_pages++;
1228                 bz->total_bpages++;
1229                 bz->free_bpages++;
1230                 BZ_UNLOCK(bz);
1231
1232                 count++;
1233                 numpages--;
1234         }
1235         return count;
1236 }
1237
1238 static void
1239 free_bounce_pages_all(bus_dma_tag_t dmat)
1240 {
1241         struct bounce_zone *bz = dmat->bounce_zone;
1242         struct bounce_page *bpage;
1243
1244         BZ_LOCK(bz);
1245
1246         while ((bpage = STAILQ_FIRST(&bz->bounce_page_list)) != NULL) {
1247                 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1248
1249                 KKASSERT(total_bounce_pages > 0);
1250                 total_bounce_pages--;
1251
1252                 KKASSERT(bz->total_bpages > 0);
1253                 bz->total_bpages--;
1254
1255                 KKASSERT(bz->free_bpages > 0);
1256                 bz->free_bpages--;
1257
1258                 contigfree((void *)bpage->vaddr, PAGE_SIZE, M_DEVBUF);
1259                 kfree(bpage, M_DEVBUF);
1260         }
1261         if (bz->total_bpages) {
1262                 kprintf("#%d bounce pages are still in use\n",
1263                         bz->total_bpages);
1264                 print_backtrace(-1);
1265         }
1266
1267         BZ_UNLOCK(bz);
1268 }
1269
1270 static void
1271 free_bounce_zone(bus_dma_tag_t dmat)
1272 {
1273         struct bounce_zone *bz = dmat->bounce_zone;
1274
1275         if (bz == NULL)
1276                 return;
1277
1278         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0)
1279                 return;
1280
1281         free_bounce_pages_all(dmat);
1282         dmat->bounce_zone = NULL;
1283
1284         sysctl_ctx_free(&bz->sysctl_ctx);
1285         kfree(bz, M_DEVBUF);
1286 }
1287
1288 /* Assume caller holds bounce zone spinlock */
1289 static int
1290 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1291 {
1292         struct bounce_zone *bz = dmat->bounce_zone;
1293         int pages;
1294
1295         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1296         if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1297                 bz->reserve_failed++;
1298                 return (map->pagesneeded - (map->pagesreserved + pages));
1299         }
1300
1301         bz->free_bpages -= pages;
1302
1303         bz->reserved_bpages += pages;
1304         KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1305
1306         map->pagesreserved += pages;
1307         pages = map->pagesneeded - map->pagesreserved;
1308
1309         return pages;
1310 }
1311
1312 static void
1313 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1314 {
1315         struct bounce_zone *bz = dmat->bounce_zone;
1316         int reserved = map->pagesreserved;
1317         bus_dmamap_t wait_map;
1318
1319         map->pagesreserved = 0;
1320         map->pagesneeded = 0;
1321
1322         if (reserved == 0)
1323                 return;
1324
1325         BZ_LOCK(bz);
1326
1327         bz->free_bpages += reserved;
1328         KKASSERT(bz->free_bpages <= bz->total_bpages);
1329
1330         KKASSERT(bz->reserved_bpages >= reserved);
1331         bz->reserved_bpages -= reserved;
1332
1333         wait_map = get_map_waiting(dmat);
1334
1335         BZ_UNLOCK(bz);
1336
1337         if (wait_map != NULL)
1338                 add_map_callback(map);
1339 }
1340
1341 static bus_addr_t
1342 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1343                 bus_size_t size)
1344 {
1345         struct bounce_zone *bz = dmat->bounce_zone;
1346         struct bounce_page *bpage;
1347
1348         KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1349         map->pagesneeded--;
1350
1351         KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1352         map->pagesreserved--;
1353
1354         BZ_LOCK(bz);
1355
1356         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1357         KASSERT(bpage != NULL, ("free page list is empty"));
1358         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1359
1360         KKASSERT(bz->reserved_bpages > 0);
1361         bz->reserved_bpages--;
1362
1363         bz->active_bpages++;
1364         KKASSERT(bz->active_bpages <= bz->total_bpages);
1365
1366         BZ_UNLOCK(bz);
1367
1368         bpage->datavaddr = vaddr;
1369         bpage->datacount = size;
1370         STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1371         return bpage->busaddr;
1372 }
1373
1374 static void
1375 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1376 {
1377         struct bounce_zone *bz = dmat->bounce_zone;
1378         bus_dmamap_t map;
1379
1380         bpage->datavaddr = 0;
1381         bpage->datacount = 0;
1382
1383         BZ_LOCK(bz);
1384
1385         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1386
1387         bz->free_bpages++;
1388         KKASSERT(bz->free_bpages <= bz->total_bpages);
1389
1390         KKASSERT(bz->active_bpages > 0);
1391         bz->active_bpages--;
1392
1393         map = get_map_waiting(dmat);
1394
1395         BZ_UNLOCK(bz);
1396
1397         if (map != NULL)
1398                 add_map_callback(map);
1399 }
1400
1401 /* Assume caller holds bounce zone spinlock */
1402 static bus_dmamap_t
1403 get_map_waiting(bus_dma_tag_t dmat)
1404 {
1405         struct bounce_zone *bz = dmat->bounce_zone;
1406         bus_dmamap_t map;
1407
1408         map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1409         if (map != NULL) {
1410                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1411                         STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1412                         bz->total_deferred++;
1413                 } else {
1414                         map = NULL;
1415                 }
1416         }
1417         return map;
1418 }
1419
1420 static void
1421 add_map_callback(bus_dmamap_t map)
1422 {
1423         spin_lock(&bounce_map_list_spin);
1424         STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1425         busdma_swi_pending = 1;
1426         setsoftvm();
1427         spin_unlock(&bounce_map_list_spin);
1428 }
1429
1430 void
1431 busdma_swi(void)
1432 {
1433         bus_dmamap_t map;
1434
1435         spin_lock(&bounce_map_list_spin);
1436         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1437                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1438                 spin_unlock(&bounce_map_list_spin);
1439                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1440                                 map->callback, map->callback_arg, /*flags*/0);
1441                 spin_lock(&bounce_map_list_spin);
1442         }
1443         spin_unlock(&bounce_map_list_spin);
1444 }