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  */
  28
  29 #include <sys/param.h>
  30 #include <sys/systm.h>
  31 #include <sys/malloc.h>
  32 #include <sys/mbuf.h>
  33 #include <sys/uio.h>
  34 #include <sys/bus_dma.h>
  35 #include <sys/kernel.h>
  36 #include <sys/sysctl.h>
  37 #include <sys/lock.h>
  38
  39 #include <sys/thread2.h>
  40 #include <sys/spinlock2.h>
  41 #include <sys/mplock2.h>
  42
  43 #include <vm/vm.h>
  44 #include <vm/vm_page.h>
  45
  46 /* XXX needed for to access pmap to convert per-proc virtual to physical */
  47 #include <sys/proc.h>
  48 #include <sys/lock.h>
  49 #include <vm/vm_map.h>
  50
  51 #include <machine/md_var.h>
  52
  53 #define MAX_BPAGES      1024
  54
  55 /*
  56  * 16 x N declared on stack.
  57  */
  58 #define BUS_DMA_CACHE_SEGMENTS  8
  59
  60 struct bounce_zone;
  61 struct bus_dmamap;
  62
  63 struct bus_dma_tag {
  64         bus_dma_tag_t   parent;
  65         bus_size_t      alignment;
  66         bus_size_t      boundary;
  67         bus_addr_t      lowaddr;
  68         bus_addr_t      highaddr;
  69         bus_dma_filter_t *filter;
  70         void            *filterarg;
  71         bus_size_t      maxsize;
  72         u_int           nsegments;
  73         bus_size_t      maxsegsz;
  74         int             flags;
  75         int             ref_count;
  76         int             map_count;
  77         bus_dma_segment_t *segments;
  78         struct bounce_zone *bounce_zone;
  79 #ifdef SMP
  80         struct spinlock spin;
  81 #else
  82         int             unused0;
  83 #endif
  84 };
  85
  86 /*
  87  * bus_dma_tag private flags
  88  */
  89 #define BUS_DMA_BOUNCE_ALIGN    BUS_DMA_BUS2
  90 #define BUS_DMA_BOUNCE_LOWADDR  BUS_DMA_BUS3
  91 #define BUS_DMA_MIN_ALLOC_COMP  BUS_DMA_BUS4
  92
  93 #define BUS_DMA_COULD_BOUNCE    (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
  94
  95 #define BUS_DMAMEM_KMALLOC(dmat) \
  96         ((dmat)->maxsize <= PAGE_SIZE && \
  97          (dmat)->alignment <= PAGE_SIZE && \
  98          (dmat)->lowaddr >= ptoa(Maxmem))
  99
 100 struct bounce_page {
 101         vm_offset_t     vaddr;          /* kva of bounce buffer */
 102         bus_addr_t      busaddr;        /* Physical address */
 103         vm_offset_t     datavaddr;      /* kva of client data */
 104         bus_size_t      datacount;      /* client data count */
 105         STAILQ_ENTRY(bounce_page) links;
 106 };
 107
 108 struct bounce_zone {
 109         STAILQ_ENTRY(bounce_zone) links;
 110         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
 111         STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 112 #ifdef SMP
 113         struct spinlock spin;
 114 #else
 115         int             unused0;
 116 #endif
 117         int             total_bpages;
 118         int             free_bpages;
 119         int             reserved_bpages;
 120         int             active_bpages;
 121         int             total_bounced;
 122         int             total_deferred;
 123         int             reserve_failed;
 124         bus_size_t      alignment;
 125         bus_addr_t      lowaddr;
 126         char            zoneid[8];
 127         char            lowaddrid[20];
 128         struct sysctl_ctx_list sysctl_ctx;
 129         struct sysctl_oid *sysctl_tree;
 130 };
 131
 132 #ifdef SMP
 133 #define BZ_LOCK(bz)     spin_lock(&(bz)->spin)
 134 #define BZ_UNLOCK(bz)   spin_unlock(&(bz)->spin)
 135 #else
 136 #define BZ_LOCK(bz)     crit_enter()
 137 #define BZ_UNLOCK(bz)   crit_exit()
 138 #endif
 139
 140 static struct lwkt_token bounce_zone_tok =
 141         LWKT_TOKEN_INITIALIZER(bounce_zone_tok);
 142 static int busdma_zonecount;
 143 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
 144         STAILQ_HEAD_INITIALIZER(bounce_zone_list);
 145
 146 static int busdma_priv_zonecount = -1;
 147
 148 int busdma_swi_pending;
 149 static int total_bounce_pages;
 150 static int max_bounce_pages = MAX_BPAGES;
 151 static int bounce_alignment = 1; /* XXX temporary */
 152
 153 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
 154 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
 155
 156 struct bus_dmamap {
 157         struct bp_list  bpages;
 158         int             pagesneeded;
 159         int             pagesreserved;
 160         bus_dma_tag_t   dmat;
 161         void            *buf;           /* unmapped buffer pointer */
 162         bus_size_t      buflen;         /* unmapped buffer length */
 163         bus_dmamap_callback_t *callback;
 164         void            *callback_arg;
 165         STAILQ_ENTRY(bus_dmamap) links;
 166 };
 167
 168 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
 169         STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
 170 static struct spinlock bounce_map_list_spin =
 171         SPINLOCK_INITIALIZER(&bounce_map_list_spin);
 172
 173 static struct bus_dmamap nobounce_dmamap;
 174
 175 static int              alloc_bounce_zone(bus_dma_tag_t);
 176 static int              alloc_bounce_pages(bus_dma_tag_t, u_int, int);
 177 static void             free_bounce_pages_all(bus_dma_tag_t);
 178 static void             free_bounce_zone(bus_dma_tag_t);
 179 static int              reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
 180 static void             return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
 181 static bus_addr_t       add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
 182                             vm_offset_t, bus_size_t);
 183 static void             free_bounce_page(bus_dma_tag_t, struct bounce_page *);
 184
 185 static bus_dmamap_t     get_map_waiting(bus_dma_tag_t);
 186 static void             add_map_callback(bus_dmamap_t);
 187
 188 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 189 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
 190            0, "Total bounce pages");
 191 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
 192            0, "Max bounce pages per bounce zone");
 193 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
 194            &bounce_alignment, 0, "Obey alignment constraint");
 195
 196 static __inline int
 197 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 198 {
 199         int retval;
 200
 201         retval = 0;
 202         do {
 203                 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
 204                      (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
 205                  && (dmat->filter == NULL ||
 206                      dmat->filter(dmat->filterarg, paddr) != 0))
 207                         retval = 1;
 208
 209                 dmat = dmat->parent;
 210         } while (retval == 0 && dmat != NULL);
 211         return (retval);
 212 }
 213
 214 static __inline
 215 bus_dma_segment_t *
 216 bus_dma_tag_lock(bus_dma_tag_t tag, bus_dma_segment_t *cache)
 217 {
 218         if (tag->flags & BUS_DMA_PROTECTED)
 219                 return(tag->segments);
 220
 221         if (tag->nsegments <= BUS_DMA_CACHE_SEGMENTS)
 222                 return(cache);
 223 #ifdef SMP
 224         spin_lock(&tag->spin);
 225 #endif
 226         return(tag->segments);
 227 }
 228
 229 static __inline
 230 void
 231 bus_dma_tag_unlock(bus_dma_tag_t tag)
 232 {
 233 #ifdef SMP
 234         if (tag->flags & BUS_DMA_PROTECTED)
 235                 return;
 236
 237         if (tag->nsegments > BUS_DMA_CACHE_SEGMENTS)
 238                 spin_unlock(&tag->spin);
 239 #endif
 240 }
 241
 242 /*
 243  * Allocate a device specific dma_tag.
 244  */
 245 int
 246 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 247                    bus_size_t boundary, bus_addr_t lowaddr,
 248                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 249                    void *filterarg, bus_size_t maxsize, int nsegments,
 250                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 251 {
 252         bus_dma_tag_t newtag;
 253         int error = 0;
 254
 255         /*
 256          * Sanity checks
 257          */
 258
 259         if (alignment == 0)
 260                 alignment = 1;
 261         if (alignment & (alignment - 1))
 262                 panic("alignment must be power of 2");
 263
 264         if (boundary != 0) {
 265                 if (boundary & (boundary - 1))
 266                         panic("boundary must be power of 2");
 267                 if (boundary < maxsegsz) {
 268                         kprintf("boundary < maxsegsz:\n");
 269                         print_backtrace(-1);
 270                         maxsegsz = boundary;
 271                 }
 272         }
 273
 274         /* Return a NULL tag on failure */
 275         *dmat = NULL;
 276
 277         newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT | M_ZERO);
 278
 279 #ifdef SMP
 280         spin_init(&newtag->spin);
 281 #endif
 282         newtag->parent = parent;
 283         newtag->alignment = alignment;
 284         newtag->boundary = boundary;
 285         newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 286         newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
 287         newtag->filter = filter;
 288         newtag->filterarg = filterarg;
 289         newtag->maxsize = maxsize;
 290         newtag->nsegments = nsegments;
 291         newtag->maxsegsz = maxsegsz;
 292         newtag->flags = flags;
 293         newtag->ref_count = 1; /* Count ourself */
 294         newtag->map_count = 0;
 295         newtag->segments = NULL;
 296         newtag->bounce_zone = NULL;
 297
 298         /* Take into account any restrictions imposed by our parent tag */
 299         if (parent != NULL) {
 300                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 301                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 302
 303                 if (newtag->boundary == 0) {
 304                         newtag->boundary = parent->boundary;
 305                 } else if (parent->boundary != 0) {
 306                         newtag->boundary = MIN(parent->boundary,
 307                                                newtag->boundary);
 308                 }
 309
 310 #ifdef notyet
 311                 newtag->alignment = MAX(parent->alignment, newtag->alignment);
 312 #endif
 313
 314                 if (newtag->filter == NULL) {
 315                         /*
 316                          * Short circuit looking at our parent directly
 317                          * since we have encapsulated all of its information
 318                          */
 319                         newtag->filter = parent->filter;
 320                         newtag->filterarg = parent->filterarg;
 321                         newtag->parent = parent->parent;
 322                 }
 323                 if (newtag->parent != NULL)
 324                         parent->ref_count++;
 325         }
 326
 327         if (newtag->lowaddr < ptoa(Maxmem))
 328                 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
 329         if (bounce_alignment && newtag->alignment > 1 &&
 330             !(newtag->flags & BUS_DMA_ALIGNED))
 331                 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
 332
 333         if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
 334             (flags & BUS_DMA_ALLOCNOW) != 0) {
 335                 struct bounce_zone *bz;
 336
 337                 /* Must bounce */
 338
 339                 error = alloc_bounce_zone(newtag);
 340                 if (error)
 341                         goto back;
 342                 bz = newtag->bounce_zone;
 343
 344                 if ((newtag->flags & BUS_DMA_ALLOCALL) == 0 &&
 345                     ptoa(bz->total_bpages) < maxsize) {
 346                         int pages;
 347
 348                         if (flags & BUS_DMA_ONEBPAGE) {
 349                                 pages = 1;
 350                         } else {
 351                                 pages = atop(round_page(maxsize)) -
 352                                         bz->total_bpages;
 353                                 pages = MAX(pages, 1);
 354                         }
 355
 356                         /* Add pages to our bounce pool */
 357                         if (alloc_bounce_pages(newtag, pages, flags) < pages)
 358                                 error = ENOMEM;
 359
 360                         /* Performed initial allocation */
 361                         newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 362                 }
 363         }
 364 back:
 365         if (error) {
 366                 free_bounce_zone(newtag);
 367                 kfree(newtag, M_DEVBUF);
 368         } else {
 369                 *dmat = newtag;
 370         }
 371         return error;
 372 }
 373
 374 int
 375 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 376 {
 377         if (dmat != NULL) {
 378                 if (dmat->map_count != 0)
 379                         return (EBUSY);
 380
 381                 while (dmat != NULL) {
 382                         bus_dma_tag_t parent;
 383
 384                         parent = dmat->parent;
 385                         dmat->ref_count--;
 386                         if (dmat->ref_count == 0) {
 387                                 free_bounce_zone(dmat);
 388                                 if (dmat->segments != NULL)
 389                                         kfree(dmat->segments, M_DEVBUF);
 390                                 kfree(dmat, M_DEVBUF);
 391                                 /*
 392                                  * Last reference count, so
 393                                  * release our reference
 394                                  * count on our parent.
 395                                  */
 396                                 dmat = parent;
 397                         } else
 398                                 dmat = NULL;
 399                 }
 400         }
 401         return (0);
 402 }
 403
 404 bus_size_t
 405 bus_dma_tag_getmaxsize(bus_dma_tag_t tag)
 406 {
 407         return(tag->maxsize);
 408 }
 409
 410 /*
 411  * Allocate a handle for mapping from kva/uva/physical
 412  * address space into bus device space.
 413  */
 414 int
 415 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 416 {
 417         int error;
 418
 419         error = 0;
 420
 421         if (dmat->segments == NULL) {
 422                 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
 423                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 424                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 425         }
 426
 427         if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
 428                 struct bounce_zone *bz;
 429                 int maxpages;
 430
 431                 /* Must bounce */
 432
 433                 if (dmat->bounce_zone == NULL) {
 434                         error = alloc_bounce_zone(dmat);
 435                         if (error)
 436                                 return error;
 437                 }
 438                 bz = dmat->bounce_zone;
 439
 440                 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
 441
 442                 /* Initialize the new map */
 443                 STAILQ_INIT(&((*mapp)->bpages));
 444
 445                 /*
 446                  * Attempt to add pages to our pool on a per-instance
 447                  * basis up to a sane limit.
 448                  */
 449                 if (dmat->flags & BUS_DMA_ALLOCALL) {
 450                         maxpages = Maxmem - atop(dmat->lowaddr);
 451                 } else if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
 452                         maxpages = max_bounce_pages;
 453                 } else {
 454                         maxpages = MIN(max_bounce_pages,
 455                                        Maxmem - atop(dmat->lowaddr));
 456                 }
 457                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 458                     (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
 459                         int pages;
 460
 461                         if (flags & BUS_DMA_ONEBPAGE) {
 462                                 pages = 1;
 463                         } else {
 464                                 pages = atop(round_page(dmat->maxsize));
 465                                 pages = MIN(maxpages - bz->total_bpages, pages);
 466                                 pages = MAX(pages, 1);
 467                         }
 468                         if (alloc_bounce_pages(dmat, pages, flags) < pages)
 469                                 error = ENOMEM;
 470
 471                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 472                                 if (!error &&
 473                                     (dmat->flags & BUS_DMA_ALLOCALL) == 0)
 474                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 475                         } else {
 476                                 error = 0;
 477                         }
 478                 }
 479         } else {
 480                 *mapp = NULL;
 481         }
 482         if (!error) {
 483                 dmat->map_count++;
 484         } else {
 485                 kfree(*mapp, M_DEVBUF);
 486                 *mapp = NULL;
 487         }
 488         return error;
 489 }
 490
 491 /*
 492  * Destroy a handle for mapping from kva/uva/physical
 493  * address space into bus device space.
 494  */
 495 int
 496 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 497 {
 498         if (map != NULL) {
 499                 if (STAILQ_FIRST(&map->bpages) != NULL)
 500                         return (EBUSY);
 501                 kfree(map, M_DEVBUF);
 502         }
 503         dmat->map_count--;
 504         return (0);
 505 }
 506
 507 static __inline bus_size_t
 508 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
 509 {
 510         bus_size_t maxsize = 0;
 511         uintptr_t vaddr = (uintptr_t)vaddr0;
 512
 513         if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
 514                 if (verify || bootverbose)
 515                         kprintf("boundary check failed\n");
 516                 if (verify)
 517                         print_backtrace(-1); /* XXX panic */
 518                 maxsize = dmat->maxsize;
 519         }
 520         if (vaddr & (dmat->alignment - 1)) {
 521                 if (verify || bootverbose)
 522                         kprintf("alignment check failed\n");
 523                 if (verify)
 524                         print_backtrace(-1); /* XXX panic */
 525                 if (dmat->maxsize < dmat->alignment)
 526                         maxsize = dmat->alignment;
 527                 else
 528                         maxsize = dmat->maxsize;
 529         }
 530         return maxsize;
 531 }
 532
 533 /*
 534  * Allocate a piece of memory that can be efficiently mapped into
 535  * bus device space based on the constraints lited in the dma tag.
 536  *
 537  * mapp is degenerate.  By definition this allocation should not require
 538  * bounce buffers so do not allocate a dma map.
 539  */
 540 int
 541 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
 542                  bus_dmamap_t *mapp)
 543 {
 544         int mflags;
 545
 546         /* If we succeed, no mapping/bouncing will be required */
 547         *mapp = NULL;
 548
 549         if (dmat->segments == NULL) {
 550                 KKASSERT(dmat->nsegments < 16384);
 551                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 552                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 553         }
 554
 555         if (flags & BUS_DMA_NOWAIT)
 556                 mflags = M_NOWAIT;
 557         else
 558                 mflags = M_WAITOK;
 559         if (flags & BUS_DMA_ZERO)
 560                 mflags |= M_ZERO;
 561
 562         if (BUS_DMAMEM_KMALLOC(dmat)) {
 563                 bus_size_t maxsize;
 564
 565                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 566
 567                 /*
 568                  * XXX
 569                  * Check whether the allocation
 570                  * - crossed a page boundary
 571                  * - was not aligned
 572                  * Retry with power-of-2 alignment in the above cases.
 573                  */
 574                 maxsize = check_kmalloc(dmat, *vaddr, 0);
 575                 if (maxsize) {
 576                         size_t size;
 577
 578                         kfree(*vaddr, M_DEVBUF);
 579                         /* XXX check for overflow? */
 580                         for (size = 1; size <= maxsize; size <<= 1)
 581                                 ;
 582                         *vaddr = kmalloc(size, M_DEVBUF, mflags);
 583                         check_kmalloc(dmat, *vaddr, 1);
 584                 }
 585         } else {
 586                 /*
 587                  * XXX Use Contigmalloc until it is merged into this facility
 588                  *     and handles multi-seg allocations.  Nobody is doing
 589                  *     multi-seg allocations yet though.
 590                  */
 591                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 592                     0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
 593         }
 594         if (*vaddr == NULL)
 595                 return (ENOMEM);
 596         return (0);
 597 }
 598
 599 /*
 600  * Free a piece of memory and it's allociated dmamap, that was allocated
 601  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 602  */
 603 void
 604 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 605 {
 606         /*
 607          * dmamem does not need to be bounced, so the map should be
 608          * NULL
 609          */
 610         if (map != NULL)
 611                 panic("bus_dmamem_free: Invalid map freed");
 612         if (BUS_DMAMEM_KMALLOC(dmat))
 613                 kfree(vaddr, M_DEVBUF);
 614         else
 615                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 616 }
 617
 618 static __inline vm_paddr_t
 619 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
 620 {
 621         if (pmap)
 622                 return pmap_extract(pmap, vaddr);
 623         else
 624                 return pmap_kextract(vaddr);
 625 }
 626
 627 /*
 628  * Utility function to load a linear buffer.  lastaddrp holds state
 629  * between invocations (for multiple-buffer loads).  segp contains
 630  * the segment following the starting one on entrace, and the ending
 631  * segment on exit.  first indicates if this is the first invocation
 632  * of this function.
 633  */
 634 static int
 635 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 636                         bus_dmamap_t map,
 637                         void *buf, bus_size_t buflen,
 638                         bus_dma_segment_t *segments,
 639                         int nsegments,
 640                         pmap_t pmap,
 641                         int flags,
 642                         vm_paddr_t *lastpaddrp,
 643                         int *segp,
 644                         int first)
 645 {
 646         vm_offset_t vaddr;
 647         vm_paddr_t paddr, nextpaddr;
 648         bus_dma_segment_t *sg;
 649         bus_addr_t bmask;
 650         int seg, error = 0;
 651
 652         if (map == NULL)
 653                 map = &nobounce_dmamap;
 654
 655 #ifdef INVARIANTS
 656         if (dmat->flags & BUS_DMA_ALIGNED)
 657                 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
 658 #endif
 659
 660         /*
 661          * If we are being called during a callback, pagesneeded will
 662          * be non-zero, so we can avoid doing the work twice.
 663          */
 664         if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 665             map != &nobounce_dmamap && map->pagesneeded == 0) {
 666                 vm_offset_t vendaddr;
 667
 668                 /*
 669                  * Count the number of bounce pages
 670                  * needed in order to complete this transfer
 671                  */
 672                 vaddr = (vm_offset_t)buf;
 673                 vendaddr = (vm_offset_t)buf + buflen;
 674
 675                 while (vaddr < vendaddr) {
 676                         paddr = _bus_dma_extract(pmap, vaddr);
 677                         if (run_filter(dmat, paddr) != 0)
 678                                 map->pagesneeded++;
 679                         vaddr += (PAGE_SIZE - (vaddr & PAGE_MASK));
 680                 }
 681         }
 682
 683         /* Reserve Necessary Bounce Pages */
 684         if (map->pagesneeded != 0) {
 685                 struct bounce_zone *bz;
 686
 687                 bz = dmat->bounce_zone;
 688                 BZ_LOCK(bz);
 689                 if (flags & BUS_DMA_NOWAIT) {
 690                         if (reserve_bounce_pages(dmat, map, 0) != 0) {
 691                                 BZ_UNLOCK(bz);
 692                                 error = ENOMEM;
 693                                 goto free_bounce;
 694                         }
 695                 } else {
 696                         if (reserve_bounce_pages(dmat, map, 1) != 0) {
 697                                 /* Queue us for resources */
 698                                 map->dmat = dmat;
 699                                 map->buf = buf;
 700                                 map->buflen = buflen;
 701
 702                                 STAILQ_INSERT_TAIL(
 703                                     &dmat->bounce_zone->bounce_map_waitinglist,
 704                                     map, links);
 705                                 BZ_UNLOCK(bz);
 706
 707                                 return (EINPROGRESS);
 708                         }
 709                 }
 710                 BZ_UNLOCK(bz);
 711         }
 712
 713         KKASSERT(*segp >= 1 && *segp <= nsegments);
 714         seg = *segp;
 715         sg = &segments[seg - 1];
 716
 717         vaddr = (vm_offset_t)buf;
 718         nextpaddr = *lastpaddrp;
 719         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 720
 721         /* force at least one segment */
 722         do {
 723                 bus_size_t size;
 724
 725                 /*
 726                  * Per-page main loop
 727                  */
 728                 paddr = _bus_dma_extract(pmap, vaddr);
 729                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 730                 if (size > buflen)
 731                         size = buflen;
 732                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 733                         /*
 734                          * note: this paddr has the same in-page offset
 735                          * as vaddr and thus the paddr above, so the
 736                          * size does not have to be recalculated
 737                          */
 738                         paddr = add_bounce_page(dmat, map, vaddr, size);
 739                 }
 740
 741                 /*
 742                  * Fill in the bus_dma_segment
 743                  */
 744                 if (first) {
 745                         sg->ds_addr = paddr;
 746                         sg->ds_len = size;
 747                         first = 0;
 748                 } else if (paddr == nextpaddr) {
 749                         sg->ds_len += size;
 750                 } else {
 751                         sg++;
 752                         seg++;
 753                         if (seg > nsegments)
 754                                 break;
 755                         sg->ds_addr = paddr;
 756                         sg->ds_len = size;
 757                 }
 758                 nextpaddr = paddr + size;
 759
 760                 /*
 761                  * Handle maxsegsz and boundary issues with a nested loop
 762                  */
 763                 for (;;) {
 764                         bus_size_t tmpsize;
 765
 766                         /*
 767                          * Limit to the boundary and maximum segment size
 768                          */
 769                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 770                                 tmpsize = dmat->boundary -
 771                                           (sg->ds_addr & ~bmask);
 772                                 if (tmpsize > dmat->maxsegsz)
 773                                         tmpsize = dmat->maxsegsz;
 774                                 KKASSERT(tmpsize < sg->ds_len);
 775                         } else if (sg->ds_len > dmat->maxsegsz) {
 776                                 tmpsize = dmat->maxsegsz;
 777                         } else {
 778                                 break;
 779                         }
 780
 781                         /*
 782                          * Futz, split the data into a new segment.
 783                          */
 784                         if (seg >= nsegments)
 785                                 goto fail;
 786                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 787                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 788                         sg[0].ds_len = tmpsize;
 789                         sg++;
 790                         seg++;
 791                 }
 792
 793                 /*
 794                  * Adjust for loop
 795                  */
 796                 buflen -= size;
 797                 vaddr += size;
 798         } while (buflen > 0);
 799 fail:
 800         if (buflen != 0)
 801                 error = EFBIG;
 802
 803         *segp = seg;
 804         *lastpaddrp = nextpaddr;
 805
 806 free_bounce:
 807         if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 808             map != &nobounce_dmamap) {
 809                 _bus_dmamap_unload(dmat, map);
 810                 return_bounce_pages(dmat, map);
 811         }
 812         return error;
 813 }
 814
 815 /*
 816  * Map the buffer buf into bus space using the dmamap map.
 817  */
 818 int
 819 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 820                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 821                 void *callback_arg, int flags)
 822 {
 823         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 824         bus_dma_segment_t *segments;
 825         vm_paddr_t lastaddr = 0;
 826         int error, nsegs = 1;
 827
 828         if (map != NULL) {
 829                 /*
 830                  * XXX
 831                  * Follow old semantics.  Once all of the callers are fixed,
 832                  * we should get rid of these internal flag "adjustment".
 833                  */
 834                 flags &= ~BUS_DMA_NOWAIT;
 835                 flags |= BUS_DMA_WAITOK;
 836
 837                 map->callback = callback;
 838                 map->callback_arg = callback_arg;
 839         }
 840
 841         segments = bus_dma_tag_lock(dmat, cache_segments);
 842         error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
 843                         segments, dmat->nsegments,
 844                         NULL, flags, &lastaddr, &nsegs, 1);
 845         if (error == EINPROGRESS) {
 846                 KKASSERT((dmat->flags &
 847                           (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL)) !=
 848                          (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL));
 849
 850                 if (dmat->flags & BUS_DMA_PROTECTED)
 851                         panic("protected dmamap callback will be defered");
 852
 853                 bus_dma_tag_unlock(dmat);
 854                 return error;
 855         }
 856         callback(callback_arg, segments, nsegs, error);
 857         bus_dma_tag_unlock(dmat);
 858         return 0;
 859 }
 860
 861 /*
 862  * Like _bus_dmamap_load(), but for mbufs.
 863  */
 864 int
 865 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 866                      struct mbuf *m0,
 867                      bus_dmamap_callback2_t *callback, void *callback_arg,
 868                      int flags)
 869 {
 870         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 871         bus_dma_segment_t *segments;
 872         int nsegs, error;
 873
 874         /*
 875          * XXX
 876          * Follow old semantics.  Once all of the callers are fixed,
 877          * we should get rid of these internal flag "adjustment".
 878          */
 879         flags &= ~BUS_DMA_WAITOK;
 880         flags |= BUS_DMA_NOWAIT;
 881
 882         segments = bus_dma_tag_lock(dmat, cache_segments);
 883         error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
 884                         segments, dmat->nsegments, &nsegs, flags);
 885         if (error) {
 886                 /* force "no valid mappings" in callback */
 887                 callback(callback_arg, segments, 0,
 888                          0, error);
 889         } else {
 890                 callback(callback_arg, segments, nsegs,
 891                          m0->m_pkthdr.len, error);
 892         }
 893         bus_dma_tag_unlock(dmat);
 894         return error;
 895 }
 896
 897 int
 898 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
 899                              struct mbuf *m0,
 900                              bus_dma_segment_t *segs, int maxsegs,
 901                              int *nsegs, int flags)
 902 {
 903         int error;
 904
 905         M_ASSERTPKTHDR(m0);
 906
 907         KASSERT(maxsegs >= 1, ("invalid maxsegs %d", maxsegs));
 908         KASSERT(maxsegs <= dmat->nsegments,
 909                 ("%d too many segments, dmat only supports %d segments",
 910                  maxsegs, dmat->nsegments));
 911         KASSERT(flags & BUS_DMA_NOWAIT,
 912                 ("only BUS_DMA_NOWAIT is supported"));
 913
 914         if (m0->m_pkthdr.len <= dmat->maxsize) {
 915                 int first = 1;
 916                 vm_paddr_t lastaddr = 0;
 917                 struct mbuf *m;
 918
 919                 *nsegs = 1;
 920                 error = 0;
 921                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 922                         if (m->m_len == 0)
 923                                 continue;
 924
 925                         error = _bus_dmamap_load_buffer(dmat, map,
 926                                         m->m_data, m->m_len,
 927                                         segs, maxsegs,
 928                                         NULL, flags, &lastaddr,
 929                                         nsegs, first);
 930                         if (error == ENOMEM && !first) {
 931                                 /*
 932                                  * Out of bounce pages due to too many
 933                                  * fragments in the mbuf chain; return
 934                                  * EFBIG instead.
 935                                  */
 936                                 error = EFBIG;
 937                         }
 938                         first = 0;
 939                 }
 940 #ifdef INVARIANTS
 941                 if (!error)
 942                         KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
 943 #endif
 944         } else {
 945                 *nsegs = 0;
 946                 error = EINVAL;
 947         }
 948         KKASSERT(error != EINPROGRESS);
 949         return error;
 950 }
 951
 952 /*
 953  * Like _bus_dmamap_load(), but for uios.
 954  */
 955 int
 956 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 957                     struct uio *uio,
 958                     bus_dmamap_callback2_t *callback, void *callback_arg,
 959                     int flags)
 960 {
 961         vm_paddr_t lastaddr;
 962         int nsegs, error, first, i;
 963         bus_size_t resid;
 964         struct iovec *iov;
 965         pmap_t pmap;
 966         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 967         bus_dma_segment_t *segments;
 968         bus_dma_segment_t *segs;
 969         int nsegs_left;
 970
 971         if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS)
 972                 segments = cache_segments;
 973         else
 974                 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments,
 975                                    M_DEVBUF, M_WAITOK | M_ZERO);
 976
 977         /*
 978          * XXX
 979          * Follow old semantics.  Once all of the callers are fixed,
 980          * we should get rid of these internal flag "adjustment".
 981          */
 982         flags &= ~BUS_DMA_WAITOK;
 983         flags |= BUS_DMA_NOWAIT;
 984
 985         resid = (bus_size_t)uio->uio_resid;
 986         iov = uio->uio_iov;
 987
 988         segs = segments;
 989         nsegs_left = dmat->nsegments;
 990
 991         if (uio->uio_segflg == UIO_USERSPACE) {
 992                 struct thread *td;
 993
 994                 td = uio->uio_td;
 995                 KASSERT(td != NULL && td->td_proc != NULL,
 996                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 997                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 998         } else {
 999                 pmap = NULL;
1000         }
1001
1002         error = 0;
1003         nsegs = 1;
1004         first = 1;
1005         lastaddr = 0;
1006         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
1007                 /*
1008                  * Now at the first iovec to load.  Load each iovec
1009                  * until we have exhausted the residual count.
1010                  */
1011                 bus_size_t minlen =
1012                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
1013                 caddr_t addr = (caddr_t) iov[i].iov_base;
1014
1015                 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
1016                                 segs, nsegs_left,
1017                                 pmap, flags, &lastaddr, &nsegs, first);
1018                 first = 0;
1019
1020                 resid -= minlen;
1021                 if (error == 0) {
1022                         nsegs_left -= nsegs;
1023                         segs += nsegs;
1024                 }
1025         }
1026
1027         /*
1028          * Minimum one DMA segment, even if 0-length buffer.
1029          */
1030         if (nsegs_left == dmat->nsegments)
1031                 --nsegs_left;
1032
1033         if (error) {
1034                 /* force "no valid mappings" in callback */
1035                 callback(callback_arg, segments, 0,
1036                          0, error);
1037         } else {
1038                 callback(callback_arg, segments, dmat->nsegments - nsegs_left,
1039                          (bus_size_t)uio->uio_resid, error);
1040         }
1041         if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS)
1042                 kfree(segments, M_DEVBUF);
1043         return error;
1044 }
1045
1046 /*
1047  * Release the mapping held by map.
1048  */
1049 void
1050 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1051 {
1052         struct bounce_page *bpage;
1053
1054         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1055                 STAILQ_REMOVE_HEAD(&map->bpages, links);
1056                 free_bounce_page(dmat, bpage);
1057         }
1058 }
1059
1060 void
1061 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1062 {
1063         struct bounce_page *bpage;
1064
1065         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1066                 /*
1067                  * Handle data bouncing.  We might also
1068                  * want to add support for invalidating
1069                  * the caches on broken hardware
1070                  */
1071                 switch (op) {
1072                 case BUS_DMASYNC_PREWRITE:
1073                         while (bpage != NULL) {
1074                                 bcopy((void *)bpage->datavaddr,
1075                                       (void *)bpage->vaddr,
1076                                       bpage->datacount);
1077                                 bpage = STAILQ_NEXT(bpage, links);
1078                         }
1079                         dmat->bounce_zone->total_bounced++;
1080                         break;
1081
1082                 case BUS_DMASYNC_POSTREAD:
1083                         while (bpage != NULL) {
1084                                 bcopy((void *)bpage->vaddr,
1085                                       (void *)bpage->datavaddr,
1086                                       bpage->datacount);
1087                                 bpage = STAILQ_NEXT(bpage, links);
1088                         }
1089                         dmat->bounce_zone->total_bounced++;
1090                         break;
1091
1092                 case BUS_DMASYNC_PREREAD:
1093                 case BUS_DMASYNC_POSTWRITE:
1094                         /* No-ops */
1095                         break;
1096                 }
1097         }
1098 }
1099
1100 static int
1101 alloc_bounce_zone(bus_dma_tag_t dmat)
1102 {
1103         struct bounce_zone *bz, *new_bz;
1104
1105         KASSERT(dmat->bounce_zone == NULL,
1106                 ("bounce zone was already assigned"));
1107
1108         new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1109
1110         lwkt_gettoken(&bounce_zone_tok);
1111
1112         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1113                 /*
1114                  * For shared bounce zone, check to see
1115                  * if we already have a suitable zone
1116                  */
1117                 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1118                         if (dmat->alignment <= bz->alignment &&
1119                             dmat->lowaddr >= bz->lowaddr) {
1120                                 lwkt_reltoken(&bounce_zone_tok);
1121
1122                                 dmat->bounce_zone = bz;
1123                                 kfree(new_bz, M_DEVBUF);
1124                                 return 0;
1125                         }
1126                 }
1127         }
1128         bz = new_bz;
1129
1130 #ifdef SMP
1131         spin_init(&bz->spin);
1132 #endif
1133         STAILQ_INIT(&bz->bounce_page_list);
1134         STAILQ_INIT(&bz->bounce_map_waitinglist);
1135         bz->free_bpages = 0;
1136         bz->reserved_bpages = 0;
1137         bz->active_bpages = 0;
1138         bz->lowaddr = dmat->lowaddr;
1139         bz->alignment = round_page(dmat->alignment);
1140         ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1141
1142         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1143                 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1144                 busdma_zonecount++;
1145                 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1146         } else {
1147                 ksnprintf(bz->zoneid, 8, "zone%d", busdma_priv_zonecount);
1148                 busdma_priv_zonecount--;
1149         }
1150
1151         lwkt_reltoken(&bounce_zone_tok);
1152
1153         dmat->bounce_zone = bz;
1154
1155         sysctl_ctx_init(&bz->sysctl_ctx);
1156         bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1157             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1158             CTLFLAG_RD, 0, "");
1159         if (bz->sysctl_tree == NULL) {
1160                 sysctl_ctx_free(&bz->sysctl_ctx);
1161                 return 0;       /* XXX error code? */
1162         }
1163
1164         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1165             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1166             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1167             "Total bounce pages");
1168         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1169             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1170             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1171             "Free bounce pages");
1172         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1173             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1174             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1175             "Reserved bounce pages");
1176         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1177             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1178             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1179             "Active bounce pages");
1180         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1181             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1182             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1183             "Total bounce requests");
1184         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1185             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1186             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1187             "Total bounce requests that were deferred");
1188         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1189             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1190             "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1191             "Total bounce page reservations that were failed");
1192         SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1193             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1194             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1195         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1196             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1197             "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1198
1199         return 0;
1200 }
1201
1202 static int
1203 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1204 {
1205         struct bounce_zone *bz = dmat->bounce_zone;
1206         int count = 0, mflags;
1207
1208         if (flags & BUS_DMA_NOWAIT)
1209                 mflags = M_NOWAIT;
1210         else
1211                 mflags = M_WAITOK;
1212
1213         while (numpages > 0) {
1214                 struct bounce_page *bpage;
1215
1216                 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1217
1218                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1219                                                          mflags, 0ul,
1220                                                          bz->lowaddr,
1221                                                          bz->alignment, 0);
1222                 if (bpage->vaddr == 0) {
1223                         kfree(bpage, M_DEVBUF);
1224                         break;
1225                 }
1226                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1227
1228                 BZ_LOCK(bz);
1229                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1230                 total_bounce_pages++;
1231                 bz->total_bpages++;
1232                 bz->free_bpages++;
1233                 BZ_UNLOCK(bz);
1234
1235                 count++;
1236                 numpages--;
1237         }
1238         return count;
1239 }
1240
1241 static void
1242 free_bounce_pages_all(bus_dma_tag_t dmat)
1243 {
1244         struct bounce_zone *bz = dmat->bounce_zone;
1245         struct bounce_page *bpage;
1246
1247         BZ_LOCK(bz);
1248
1249         while ((bpage = STAILQ_FIRST(&bz->bounce_page_list)) != NULL) {
1250                 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1251
1252                 KKASSERT(total_bounce_pages > 0);
1253                 total_bounce_pages--;
1254
1255                 KKASSERT(bz->total_bpages > 0);
1256                 bz->total_bpages--;
1257
1258                 KKASSERT(bz->free_bpages > 0);
1259                 bz->free_bpages--;
1260
1261                 BZ_UNLOCK(bz);
1262                 contigfree((void *)bpage->vaddr, PAGE_SIZE, M_DEVBUF);
1263                 kfree(bpage, M_DEVBUF);
1264                 BZ_LOCK(bz);
1265         }
1266         if (bz->total_bpages) {
1267                 kprintf("#%d bounce pages are still in use\n",
1268                         bz->total_bpages);
1269                 print_backtrace(-1);
1270         }
1271
1272         BZ_UNLOCK(bz);
1273 }
1274
1275 static void
1276 free_bounce_zone(bus_dma_tag_t dmat)
1277 {
1278         struct bounce_zone *bz = dmat->bounce_zone;
1279
1280         if (bz == NULL)
1281                 return;
1282
1283         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0)
1284                 return;
1285
1286         free_bounce_pages_all(dmat);
1287         dmat->bounce_zone = NULL;
1288
1289         if (bz->sysctl_tree != NULL)
1290                 sysctl_ctx_free(&bz->sysctl_ctx);
1291         kfree(bz, M_DEVBUF);
1292 }
1293
1294 /* Assume caller holds bounce zone spinlock */
1295 static int
1296 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1297 {
1298         struct bounce_zone *bz = dmat->bounce_zone;
1299         int pages;
1300
1301         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1302         if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1303                 bz->reserve_failed++;
1304                 return (map->pagesneeded - (map->pagesreserved + pages));
1305         }
1306
1307         bz->free_bpages -= pages;
1308
1309         bz->reserved_bpages += pages;
1310         KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1311
1312         map->pagesreserved += pages;
1313         pages = map->pagesneeded - map->pagesreserved;
1314
1315         return pages;
1316 }
1317
1318 static void
1319 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1320 {
1321         struct bounce_zone *bz = dmat->bounce_zone;
1322         int reserved = map->pagesreserved;
1323         bus_dmamap_t wait_map;
1324
1325         map->pagesreserved = 0;
1326         map->pagesneeded = 0;
1327
1328         if (reserved == 0)
1329                 return;
1330
1331         BZ_LOCK(bz);
1332
1333         bz->free_bpages += reserved;
1334         KKASSERT(bz->free_bpages <= bz->total_bpages);
1335
1336         KKASSERT(bz->reserved_bpages >= reserved);
1337         bz->reserved_bpages -= reserved;
1338
1339         wait_map = get_map_waiting(dmat);
1340
1341         BZ_UNLOCK(bz);
1342
1343         if (wait_map != NULL)
1344                 add_map_callback(map);
1345 }
1346
1347 static bus_addr_t
1348 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1349                 bus_size_t size)
1350 {
1351         struct bounce_zone *bz = dmat->bounce_zone;
1352         struct bounce_page *bpage;
1353
1354         KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1355         map->pagesneeded--;
1356
1357         KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1358         map->pagesreserved--;
1359
1360         BZ_LOCK(bz);
1361
1362         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1363         KASSERT(bpage != NULL, ("free page list is empty"));
1364         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1365
1366         KKASSERT(bz->reserved_bpages > 0);
1367         bz->reserved_bpages--;
1368
1369         bz->active_bpages++;
1370         KKASSERT(bz->active_bpages <= bz->total_bpages);
1371
1372         BZ_UNLOCK(bz);
1373
1374         if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1375                 /* Page offset needs to be preserved. */
1376                 bpage->vaddr |= vaddr & PAGE_MASK;
1377                 bpage->busaddr |= vaddr & PAGE_MASK;
1378         }
1379         bpage->datavaddr = vaddr;
1380         bpage->datacount = size;
1381         STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1382         return bpage->busaddr;
1383 }
1384
1385 static void
1386 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1387 {
1388         struct bounce_zone *bz = dmat->bounce_zone;
1389         bus_dmamap_t map;
1390
1391         bpage->datavaddr = 0;
1392         bpage->datacount = 0;
1393
1394         if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1395                 /*
1396                  * Reset the bounce page to start at offset 0.  Other uses
1397                  * of this bounce page may need to store a full page of
1398                  * data and/or assume it starts on a page boundary.
1399                  */
1400                 bpage->vaddr &= ~PAGE_MASK;
1401                 bpage->busaddr &= ~PAGE_MASK;
1402         }
1403
1404         BZ_LOCK(bz);
1405
1406         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1407
1408         bz->free_bpages++;
1409         KKASSERT(bz->free_bpages <= bz->total_bpages);
1410
1411         KKASSERT(bz->active_bpages > 0);
1412         bz->active_bpages--;
1413
1414         map = get_map_waiting(dmat);
1415
1416         BZ_UNLOCK(bz);
1417
1418         if (map != NULL)
1419                 add_map_callback(map);
1420 }
1421
1422 /* Assume caller holds bounce zone spinlock */
1423 static bus_dmamap_t
1424 get_map_waiting(bus_dma_tag_t dmat)
1425 {
1426         struct bounce_zone *bz = dmat->bounce_zone;
1427         bus_dmamap_t map;
1428
1429         map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1430         if (map != NULL) {
1431                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1432                         STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1433                         bz->total_deferred++;
1434                 } else {
1435                         map = NULL;
1436                 }
1437         }
1438         return map;
1439 }
1440
1441 static void
1442 add_map_callback(bus_dmamap_t map)
1443 {
1444         spin_lock(&bounce_map_list_spin);
1445         STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1446         busdma_swi_pending = 1;
1447         setsoftvm();
1448         spin_unlock(&bounce_map_list_spin);
1449 }
1450
1451 void
1452 busdma_swi(void)
1453 {
1454         bus_dmamap_t map;
1455
1456         spin_lock(&bounce_map_list_spin);
1457         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1458                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1459                 spin_unlock(&bounce_map_list_spin);
1460                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1461                                 map->callback, map->callback_arg, /*flags*/0);
1462                 spin_lock(&bounce_map_list_spin);
1463         }
1464         spin_unlock(&bounce_map_list_spin);
1465 }