sys/platform/pc64/x86_64/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/spinlock2.h>
  40
  41 #include <vm/vm.h>
  42 #include <vm/vm_page.h>
  43
  44 /* XXX needed for to access pmap to convert per-proc virtual to physical */
  45 #include <sys/proc.h>
  46 #include <vm/vm_map.h>
  47
  48 #include <machine/md_var.h>
  49 #include <machine/pmap.h>
  50
  51 #include <bus/cam/cam.h>
  52 #include <bus/cam/cam_ccb.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         struct spinlock spin;
  81 };
  82
  83 /*
  84  * bus_dma_tag private flags
  85  */
  86 #define BUS_DMA_BOUNCE_ALIGN    BUS_DMA_BUS2
  87 #define BUS_DMA_BOUNCE_LOWADDR  BUS_DMA_BUS3
  88 #define BUS_DMA_MIN_ALLOC_COMP  BUS_DMA_BUS4
  89
  90 #define BUS_DMA_COULD_BOUNCE    (BUS_DMA_BOUNCE_LOWADDR | BUS_DMA_BOUNCE_ALIGN)
  91
  92 #define BUS_DMAMEM_KMALLOC(dmat) \
  93         ((dmat)->maxsize <= PAGE_SIZE && \
  94          (dmat)->alignment <= PAGE_SIZE && \
  95          (dmat)->lowaddr >= ptoa(Maxmem))
  96
  97 struct bounce_page {
  98         vm_offset_t     vaddr;          /* kva of bounce buffer */
  99         bus_addr_t      busaddr;        /* Physical address */
 100         vm_offset_t     datavaddr;      /* kva of client data */
 101         bus_size_t      datacount;      /* client data count */
 102         STAILQ_ENTRY(bounce_page) links;
 103 };
 104
 105 struct bounce_zone {
 106         STAILQ_ENTRY(bounce_zone) links;
 107         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
 108         STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 109         struct spinlock spin;
 110         int             total_bpages;
 111         int             free_bpages;
 112         int             reserved_bpages;
 113         int             active_bpages;
 114         int             total_bounced;
 115         int             total_deferred;
 116         int             reserve_failed;
 117         bus_size_t      alignment;
 118         bus_addr_t      lowaddr;
 119         char            zoneid[8];
 120         char            lowaddrid[20];
 121         struct sysctl_ctx_list sysctl_ctx;
 122         struct sysctl_oid *sysctl_tree;
 123 };
 124
 125 #define BZ_LOCK(bz)     spin_lock(&(bz)->spin)
 126 #define BZ_UNLOCK(bz)   spin_unlock(&(bz)->spin)
 127
 128 static struct lwkt_token bounce_zone_tok =
 129         LWKT_TOKEN_INITIALIZER(bounce_zone_token);
 130 static int busdma_zonecount;
 131 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
 132         STAILQ_HEAD_INITIALIZER(bounce_zone_list);
 133
 134 static int busdma_priv_zonecount = -1;
 135
 136 int busdma_swi_pending;
 137 static int total_bounce_pages;
 138 static int max_bounce_pages = MAX_BPAGES;
 139 static int bounce_alignment = 1; /* XXX temporary */
 140
 141 TUNABLE_INT("hw.busdma.max_bpages", &max_bounce_pages);
 142 TUNABLE_INT("hw.busdma.bounce_alignment", &bounce_alignment);
 143
 144 struct bus_dmamap {
 145         struct bp_list  bpages;
 146         int             pagesneeded;
 147         int             pagesreserved;
 148         bus_dma_tag_t   dmat;
 149         void            *buf;           /* unmapped buffer pointer */
 150         bus_size_t      buflen;         /* unmapped buffer length */
 151         bus_dmamap_callback_t *callback;
 152         void            *callback_arg;
 153         STAILQ_ENTRY(bus_dmamap) links;
 154 };
 155
 156 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
 157         STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
 158 static struct spinlock bounce_map_list_spin =
 159         SPINLOCK_INITIALIZER(&bounce_map_list_spin, "bounce_map_list_spin");
 160
 161 static struct bus_dmamap nobounce_dmamap;
 162
 163 static int              alloc_bounce_zone(bus_dma_tag_t);
 164 static int              alloc_bounce_pages(bus_dma_tag_t, u_int, int);
 165 static void             free_bounce_pages_all(bus_dma_tag_t);
 166 static void             free_bounce_zone(bus_dma_tag_t);
 167 static int              reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
 168 static void             return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
 169 static bus_addr_t       add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
 170                             vm_offset_t, bus_size_t *);
 171 static void             free_bounce_page(bus_dma_tag_t, struct bounce_page *);
 172
 173 static bus_dmamap_t     get_map_waiting(bus_dma_tag_t);
 174 static void             add_map_callback(bus_dmamap_t);
 175
 176 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 177 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
 178            0, "Total bounce pages");
 179 SYSCTL_INT(_hw_busdma, OID_AUTO, max_bpages, CTLFLAG_RD, &max_bounce_pages,
 180            0, "Max bounce pages per bounce zone");
 181 SYSCTL_INT(_hw_busdma, OID_AUTO, bounce_alignment, CTLFLAG_RD,
 182            &bounce_alignment, 0, "Obey alignment constraint");
 183
 184 static __inline int
 185 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 186 {
 187         int retval;
 188
 189         retval = 0;
 190         do {
 191                 if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr) ||
 192                      (bounce_alignment && (paddr & (dmat->alignment - 1)) != 0))
 193                  && (dmat->filter == NULL ||
 194                      dmat->filter(dmat->filterarg, paddr) != 0))
 195                         retval = 1;
 196
 197                 dmat = dmat->parent;
 198         } while (retval == 0 && dmat != NULL);
 199         return (retval);
 200 }
 201
 202 static __inline
 203 bus_dma_segment_t *
 204 bus_dma_tag_lock(bus_dma_tag_t tag, bus_dma_segment_t *cache)
 205 {
 206         if (tag->flags & BUS_DMA_PROTECTED)
 207                 return(tag->segments);
 208
 209         if (tag->nsegments <= BUS_DMA_CACHE_SEGMENTS)
 210                 return(cache);
 211         spin_lock(&tag->spin);
 212         return(tag->segments);
 213 }
 214
 215 static __inline
 216 void
 217 bus_dma_tag_unlock(bus_dma_tag_t tag)
 218 {
 219         if (tag->flags & BUS_DMA_PROTECTED)
 220                 return;
 221
 222         if (tag->nsegments > BUS_DMA_CACHE_SEGMENTS)
 223                 spin_unlock(&tag->spin);
 224 }
 225
 226 /*
 227  * Allocate a device specific dma_tag.
 228  */
 229 int
 230 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 231                    bus_size_t boundary, bus_addr_t lowaddr,
 232                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 233                    void *filterarg, bus_size_t maxsize, int nsegments,
 234                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 235 {
 236         bus_dma_tag_t newtag;
 237         int error = 0;
 238
 239         /*
 240          * Sanity checks
 241          */
 242
 243         if (alignment == 0)
 244                 alignment = 1;
 245         if (alignment & (alignment - 1))
 246                 panic("alignment must be power of 2");
 247
 248         if (boundary != 0) {
 249                 if (boundary & (boundary - 1))
 250                         panic("boundary must be power of 2");
 251                 if (boundary < maxsegsz) {
 252                         kprintf("boundary < maxsegsz:\n");
 253                         print_backtrace(-1);
 254                         maxsegsz = boundary;
 255                 }
 256         }
 257
 258         /* Return a NULL tag on failure */
 259         *dmat = NULL;
 260
 261         newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT | M_ZERO);
 262
 263         spin_init(&newtag->spin, "busdmacreate");
 264         newtag->parent = parent;
 265         newtag->alignment = alignment;
 266         newtag->boundary = boundary;
 267         newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 268         newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
 269         newtag->filter = filter;
 270         newtag->filterarg = filterarg;
 271         newtag->maxsize = maxsize;
 272         newtag->nsegments = nsegments;
 273         newtag->maxsegsz = maxsegsz;
 274         newtag->flags = flags;
 275         newtag->ref_count = 1; /* Count ourself */
 276         newtag->map_count = 0;
 277         newtag->segments = NULL;
 278         newtag->bounce_zone = NULL;
 279
 280         /* Take into account any restrictions imposed by our parent tag */
 281         if (parent != NULL) {
 282                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 283                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 284
 285                 if (newtag->boundary == 0) {
 286                         newtag->boundary = parent->boundary;
 287                 } else if (parent->boundary != 0) {
 288                         newtag->boundary = MIN(parent->boundary,
 289                                                newtag->boundary);
 290                 }
 291
 292 #ifdef notyet
 293                 newtag->alignment = MAX(parent->alignment, newtag->alignment);
 294 #endif
 295
 296                 if (newtag->filter == NULL) {
 297                         /*
 298                          * Short circuit looking at our parent directly
 299                          * since we have encapsulated all of its information
 300                          */
 301                         newtag->filter = parent->filter;
 302                         newtag->filterarg = parent->filterarg;
 303                         newtag->parent = parent->parent;
 304                 }
 305                 if (newtag->parent != NULL)
 306                         parent->ref_count++;
 307         }
 308
 309         if (newtag->lowaddr < ptoa(Maxmem))
 310                 newtag->flags |= BUS_DMA_BOUNCE_LOWADDR;
 311         if (bounce_alignment && newtag->alignment > 1 &&
 312             !(newtag->flags & BUS_DMA_ALIGNED))
 313                 newtag->flags |= BUS_DMA_BOUNCE_ALIGN;
 314
 315         if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
 316             (flags & BUS_DMA_ALLOCNOW) != 0) {
 317                 struct bounce_zone *bz;
 318
 319                 /* Must bounce */
 320
 321                 error = alloc_bounce_zone(newtag);
 322                 if (error)
 323                         goto back;
 324                 bz = newtag->bounce_zone;
 325
 326                 if ((newtag->flags & BUS_DMA_ALLOCALL) == 0 &&
 327                     ptoa(bz->total_bpages) < maxsize) {
 328                         int pages;
 329
 330                         if (flags & BUS_DMA_ONEBPAGE) {
 331                                 pages = 1;
 332                         } else {
 333                                 pages = atop(round_page(maxsize)) -
 334                                         bz->total_bpages;
 335                                 pages = MAX(pages, 1);
 336                         }
 337
 338                         /* Add pages to our bounce pool */
 339                         if (alloc_bounce_pages(newtag, pages, flags) < pages)
 340                                 error = ENOMEM;
 341
 342                         /* Performed initial allocation */
 343                         newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 344                 }
 345         }
 346 back:
 347         if (error) {
 348                 free_bounce_zone(newtag);
 349                 kfree(newtag, M_DEVBUF);
 350         } else {
 351                 *dmat = newtag;
 352         }
 353         return error;
 354 }
 355
 356 int
 357 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 358 {
 359         if (dmat != NULL) {
 360                 if (dmat->map_count != 0)
 361                         return (EBUSY);
 362
 363                 while (dmat != NULL) {
 364                         bus_dma_tag_t parent;
 365
 366                         parent = dmat->parent;
 367                         dmat->ref_count--;
 368                         if (dmat->ref_count == 0) {
 369                                 free_bounce_zone(dmat);
 370                                 if (dmat->segments != NULL)
 371                                         kfree(dmat->segments, M_DEVBUF);
 372                                 kfree(dmat, M_DEVBUF);
 373                                 /*
 374                                  * Last reference count, so
 375                                  * release our reference
 376                                  * count on our parent.
 377                                  */
 378                                 dmat = parent;
 379                         } else
 380                                 dmat = NULL;
 381                 }
 382         }
 383         return (0);
 384 }
 385
 386 bus_size_t
 387 bus_dma_tag_getmaxsize(bus_dma_tag_t tag)
 388 {
 389         return(tag->maxsize);
 390 }
 391
 392 /*
 393  * Allocate a handle for mapping from kva/uva/physical
 394  * address space into bus device space.
 395  */
 396 int
 397 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 398 {
 399         int error;
 400
 401         error = 0;
 402
 403         if (dmat->segments == NULL) {
 404                 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
 405                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 406                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 407         }
 408
 409         if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
 410                 struct bounce_zone *bz;
 411                 int maxpages;
 412
 413                 /* Must bounce */
 414
 415                 if (dmat->bounce_zone == NULL) {
 416                         error = alloc_bounce_zone(dmat);
 417                         if (error)
 418                                 return error;
 419                 }
 420                 bz = dmat->bounce_zone;
 421
 422                 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
 423
 424                 /* Initialize the new map */
 425                 STAILQ_INIT(&((*mapp)->bpages));
 426
 427                 /*
 428                  * Attempt to add pages to our pool on a per-instance
 429                  * basis up to a sane limit.
 430                  */
 431                 if (dmat->flags & BUS_DMA_ALLOCALL) {
 432                         maxpages = Maxmem - atop(dmat->lowaddr);
 433                 } else if (dmat->flags & BUS_DMA_BOUNCE_ALIGN) {
 434                         maxpages = max_bounce_pages;
 435                 } else {
 436                         maxpages = MIN(max_bounce_pages,
 437                                        Maxmem - atop(dmat->lowaddr));
 438                 }
 439                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 440                     (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
 441                         int pages;
 442
 443                         if (flags & BUS_DMA_ONEBPAGE) {
 444                                 pages = 1;
 445                         } else {
 446                                 pages = atop(round_page(dmat->maxsize));
 447                                 pages = MIN(maxpages - bz->total_bpages, pages);
 448                                 pages = MAX(pages, 1);
 449                         }
 450                         if (alloc_bounce_pages(dmat, pages, flags) < pages)
 451                                 error = ENOMEM;
 452
 453                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 454                                 if (!error &&
 455                                     (dmat->flags & BUS_DMA_ALLOCALL) == 0)
 456                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 457                         } else {
 458                                 error = 0;
 459                         }
 460                 }
 461         } else {
 462                 *mapp = NULL;
 463         }
 464         if (!error) {
 465                 dmat->map_count++;
 466         } else {
 467                 kfree(*mapp, M_DEVBUF);
 468                 *mapp = NULL;
 469         }
 470         return error;
 471 }
 472
 473 /*
 474  * Destroy a handle for mapping from kva/uva/physical
 475  * address space into bus device space.
 476  */
 477 int
 478 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 479 {
 480         if (map != NULL && map != (void *)-1) {
 481                 if (STAILQ_FIRST(&map->bpages) != NULL)
 482                         return (EBUSY);
 483                 kfree(map, M_DEVBUF);
 484         }
 485         dmat->map_count--;
 486         return (0);
 487 }
 488
 489 static __inline bus_size_t
 490 check_kmalloc(bus_dma_tag_t dmat, const void *vaddr0, int verify)
 491 {
 492         bus_size_t maxsize = 0;
 493         uintptr_t vaddr = (uintptr_t)vaddr0;
 494
 495         if ((vaddr ^ (vaddr + dmat->maxsize - 1)) & ~PAGE_MASK) {
 496                 if (verify)
 497                         panic("boundary check failed\n");
 498                 maxsize = dmat->maxsize;
 499         }
 500         if (vaddr & (dmat->alignment - 1)) {
 501                 if (verify)
 502                         panic("alignment check failed\n");
 503                 if (dmat->maxsize < dmat->alignment)
 504                         maxsize = dmat->alignment;
 505                 else
 506                         maxsize = dmat->maxsize;
 507         }
 508         return maxsize;
 509 }
 510
 511 /*
 512  * Allocate a piece of memory that can be efficiently mapped into
 513  * bus device space based on the constraints lited in the dma tag.
 514  *
 515  * Use *mapp to record whether we were able to use kmalloc()
 516  * or whether we had to use contigmalloc().
 517  */
 518 int
 519 bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags,
 520                  bus_dmamap_t *mapp)
 521 {
 522         vm_memattr_t attr;
 523         int mflags;
 524
 525         /* If we succeed, no mapping/bouncing will be required */
 526         *mapp = NULL;
 527
 528         if (dmat->segments == NULL) {
 529                 KKASSERT(dmat->nsegments < 16384);
 530                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 531                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 532         }
 533
 534         if (flags & BUS_DMA_NOWAIT)
 535                 mflags = M_NOWAIT;
 536         else
 537                 mflags = M_WAITOK;
 538         if (flags & BUS_DMA_ZERO)
 539                 mflags |= M_ZERO;
 540         if (flags & BUS_DMA_NOCACHE)
 541                 attr = VM_MEMATTR_UNCACHEABLE;
 542         else
 543                 attr = VM_MEMATTR_DEFAULT;
 544
 545         /* XXX must alloc with correct mem attribute here */
 546         if (BUS_DMAMEM_KMALLOC(dmat) && attr == VM_MEMATTR_DEFAULT) {
 547                 bus_size_t maxsize;
 548
 549                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 550
 551                 /*
 552                  * XXX
 553                  * Check whether the allocation
 554                  * - crossed a page boundary
 555                  * - was not aligned
 556                  * Retry with power-of-2 alignment in the above cases.
 557                  */
 558                 maxsize = check_kmalloc(dmat, *vaddr, 0);
 559                 if (maxsize) {
 560                         kfree(*vaddr, M_DEVBUF);
 561                         *vaddr = kmalloc(maxsize, M_DEVBUF,
 562                                          mflags | M_POWEROF2);
 563                         check_kmalloc(dmat, *vaddr, 1);
 564                 }
 565         } else {
 566                 /*
 567                  * XXX Use Contigmalloc until it is merged into this facility
 568                  *     and handles multi-seg allocations.  Nobody is doing
 569                  *     multi-seg allocations yet though.
 570                  */
 571                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 572                                       0ul, dmat->lowaddr,
 573                                       dmat->alignment, dmat->boundary);
 574                 *mapp = (void  *)-1;
 575         }
 576         if (*vaddr == NULL)
 577                 return (ENOMEM);
 578
 579         if (attr != VM_MEMATTR_DEFAULT) {
 580                 pmap_change_attr((vm_offset_t)(*vaddr),
 581                                  dmat->maxsize / PAGE_SIZE, attr);
 582         }
 583         return (0);
 584 }
 585
 586 /*
 587  * Free a piece of memory and it's allociated dmamap, that was allocated
 588  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 589  */
 590 void
 591 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 592 {
 593         /*
 594          * dmamem does not need to be bounced, so the map should be
 595          * NULL
 596          */
 597         if (map != NULL && map != (void *)-1)
 598                 panic("bus_dmamem_free: Invalid map freed");
 599         if (map == NULL)
 600                 kfree(vaddr, M_DEVBUF);
 601         else
 602                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 603 }
 604
 605 static __inline vm_paddr_t
 606 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
 607 {
 608         if (pmap)
 609                 return pmap_extract(pmap, vaddr, NULL);
 610         else
 611                 return pmap_kextract(vaddr);
 612 }
 613
 614 /*
 615  * Utility function to load a linear buffer.  lastaddrp holds state
 616  * between invocations (for multiple-buffer loads).  segp contains
 617  * the segment following the starting one on entrace, and the ending
 618  * segment on exit.  first indicates if this is the first invocation
 619  * of this function.
 620  */
 621 static int
 622 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 623                         bus_dmamap_t map,
 624                         void *buf, bus_size_t buflen,
 625                         bus_dma_segment_t *segments,
 626                         int nsegments,
 627                         pmap_t pmap,
 628                         int flags,
 629                         vm_paddr_t *lastpaddrp,
 630                         int *segp,
 631                         int first)
 632 {
 633         vm_offset_t vaddr;
 634         vm_paddr_t paddr, nextpaddr;
 635         bus_dma_segment_t *sg;
 636         bus_addr_t bmask;
 637         int seg, error = 0;
 638
 639         if (map == NULL || map == (void *)-1)
 640                 map = &nobounce_dmamap;
 641
 642 #ifdef INVARIANTS
 643         if (dmat->flags & BUS_DMA_ALIGNED)
 644                 KKASSERT(((uintptr_t)buf & (dmat->alignment - 1)) == 0);
 645 #endif
 646
 647         /*
 648          * If we are being called during a callback, pagesneeded will
 649          * be non-zero, so we can avoid doing the work twice.
 650          */
 651         if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 652             map != &nobounce_dmamap && map->pagesneeded == 0) {
 653                 vm_offset_t vendaddr;
 654
 655                 /*
 656                  * Count the number of bounce pages
 657                  * needed in order to complete this transfer
 658                  */
 659                 vaddr = (vm_offset_t)buf;
 660                 vendaddr = (vm_offset_t)buf + buflen;
 661
 662                 while (vaddr < vendaddr) {
 663                         paddr = _bus_dma_extract(pmap, vaddr);
 664                         if (run_filter(dmat, paddr) != 0)
 665                                 map->pagesneeded++;
 666                         vaddr += (PAGE_SIZE - (vaddr & PAGE_MASK));
 667                 }
 668         }
 669
 670         /* Reserve Necessary Bounce Pages */
 671         if (map->pagesneeded != 0) {
 672                 struct bounce_zone *bz;
 673
 674                 bz = dmat->bounce_zone;
 675                 BZ_LOCK(bz);
 676                 if (flags & BUS_DMA_NOWAIT) {
 677                         if (reserve_bounce_pages(dmat, map, 0) != 0) {
 678                                 BZ_UNLOCK(bz);
 679                                 error = ENOMEM;
 680                                 goto free_bounce;
 681                         }
 682                 } else {
 683                         if (reserve_bounce_pages(dmat, map, 1) != 0) {
 684                                 /* Queue us for resources */
 685                                 map->dmat = dmat;
 686                                 map->buf = buf;
 687                                 map->buflen = buflen;
 688
 689                                 STAILQ_INSERT_TAIL(
 690                                     &dmat->bounce_zone->bounce_map_waitinglist,
 691                                     map, links);
 692                                 BZ_UNLOCK(bz);
 693
 694                                 return (EINPROGRESS);
 695                         }
 696                 }
 697                 BZ_UNLOCK(bz);
 698         }
 699
 700         KKASSERT(*segp >= 1 && *segp <= nsegments);
 701         seg = *segp;
 702         sg = &segments[seg - 1];
 703
 704         vaddr = (vm_offset_t)buf;
 705         nextpaddr = *lastpaddrp;
 706         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 707
 708         /* force at least one segment */
 709         do {
 710                 bus_size_t size;
 711
 712                 /*
 713                  * Per-page main loop
 714                  */
 715                 paddr = _bus_dma_extract(pmap, vaddr);
 716                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 717                 if (size > buflen)
 718                         size = buflen;
 719                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 720                         /*
 721                          * NOTE: paddr may have different in-page offset,
 722                          *       unless BUS_DMA_KEEP_PG_OFFSET is set.
 723                          */
 724                         paddr = add_bounce_page(dmat, map, vaddr, &size);
 725                 }
 726
 727                 /*
 728                  * Fill in the bus_dma_segment
 729                  */
 730                 if (first) {
 731                         sg->ds_addr = paddr;
 732                         sg->ds_len = size;
 733                         first = 0;
 734                 } else if (paddr == nextpaddr) {
 735                         sg->ds_len += size;
 736                 } else {
 737                         sg++;
 738                         seg++;
 739                         if (seg > nsegments)
 740                                 break;
 741                         sg->ds_addr = paddr;
 742                         sg->ds_len = size;
 743                 }
 744                 nextpaddr = paddr + size;
 745
 746                 /*
 747                  * Handle maxsegsz and boundary issues with a nested loop
 748                  */
 749                 for (;;) {
 750                         bus_size_t tmpsize;
 751
 752                         /*
 753                          * Limit to the boundary and maximum segment size
 754                          */
 755                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 756                                 tmpsize = dmat->boundary -
 757                                           (sg->ds_addr & ~bmask);
 758                                 if (tmpsize > dmat->maxsegsz)
 759                                         tmpsize = dmat->maxsegsz;
 760                                 KKASSERT(tmpsize < sg->ds_len);
 761                         } else if (sg->ds_len > dmat->maxsegsz) {
 762                                 tmpsize = dmat->maxsegsz;
 763                         } else {
 764                                 break;
 765                         }
 766
 767                         /*
 768                          * Futz, split the data into a new segment.
 769                          */
 770                         if (seg >= nsegments)
 771                                 goto fail;
 772                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 773                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 774                         sg[0].ds_len = tmpsize;
 775                         sg++;
 776                         seg++;
 777                 }
 778
 779                 /*
 780                  * Adjust for loop
 781                  */
 782                 buflen -= size;
 783                 vaddr += size;
 784         } while (buflen > 0);
 785 fail:
 786         if (buflen != 0)
 787                 error = EFBIG;
 788
 789         *segp = seg;
 790         *lastpaddrp = nextpaddr;
 791
 792 free_bounce:
 793         if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 794             map != &nobounce_dmamap) {
 795                 _bus_dmamap_unload(dmat, map);
 796                 return_bounce_pages(dmat, map);
 797         }
 798         return error;
 799 }
 800
 801 /*
 802  * Map the buffer buf into bus space using the dmamap map.
 803  */
 804 int
 805 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 806                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 807                 void *callback_arg, int flags)
 808 {
 809         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 810         bus_dma_segment_t *segments;
 811         vm_paddr_t lastaddr = 0;
 812         int error, nsegs = 1;
 813
 814         if (map != NULL && map != (void *)-1) {
 815                 /*
 816                  * XXX
 817                  * Follow old semantics.  Once all of the callers are fixed,
 818                  * we should get rid of these internal flag "adjustment".
 819                  */
 820                 flags &= ~BUS_DMA_NOWAIT;
 821                 flags |= BUS_DMA_WAITOK;
 822
 823                 map->callback = callback;
 824                 map->callback_arg = callback_arg;
 825         }
 826
 827         segments = bus_dma_tag_lock(dmat, cache_segments);
 828         error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
 829                         segments, dmat->nsegments,
 830                         NULL, flags, &lastaddr, &nsegs, 1);
 831         if (error == EINPROGRESS) {
 832                 KKASSERT((dmat->flags &
 833                           (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL)) !=
 834                          (BUS_DMA_PRIVBZONE | BUS_DMA_ALLOCALL));
 835
 836                 if (dmat->flags & BUS_DMA_PROTECTED)
 837                         panic("protected dmamap callback will be defered");
 838
 839                 bus_dma_tag_unlock(dmat);
 840                 return error;
 841         }
 842         callback(callback_arg, segments, nsegs, error);
 843         bus_dma_tag_unlock(dmat);
 844         return 0;
 845 }
 846
 847 /*
 848  * Like _bus_dmamap_load(), but for ccb.
 849  */
 850 int
 851 bus_dmamap_load_ccb(bus_dma_tag_t dmat, bus_dmamap_t map, union ccb *ccb,
 852     bus_dmamap_callback_t *callback, void *callback_arg, int flags)
 853 {
 854         const struct ccb_scsiio *csio;
 855
 856         KASSERT(ccb->ccb_h.func_code == XPT_SCSI_IO ||
 857             ccb->ccb_h.func_code == XPT_CONT_TARGET_IO,
 858             ("invalid ccb func_code %u", ccb->ccb_h.func_code));
 859         csio = &ccb->csio;
 860
 861         return (bus_dmamap_load(dmat, map, csio->data_ptr, csio->dxfer_len,
 862             callback, callback_arg, flags));
 863 }
 864
 865 /*
 866  * Like _bus_dmamap_load(), but for mbufs.
 867  */
 868 int
 869 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 870                      struct mbuf *m0,
 871                      bus_dmamap_callback2_t *callback, void *callback_arg,
 872                      int flags)
 873 {
 874         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 875         bus_dma_segment_t *segments;
 876         int nsegs, error;
 877
 878         /*
 879          * XXX
 880          * Follow old semantics.  Once all of the callers are fixed,
 881          * we should get rid of these internal flag "adjustment".
 882          */
 883         flags &= ~BUS_DMA_WAITOK;
 884         flags |= BUS_DMA_NOWAIT;
 885
 886         segments = bus_dma_tag_lock(dmat, cache_segments);
 887         error = bus_dmamap_load_mbuf_segment(dmat, map, m0,
 888                         segments, dmat->nsegments, &nsegs, flags);
 889         if (error) {
 890                 /* force "no valid mappings" in callback */
 891                 callback(callback_arg, segments, 0,
 892                          0, error);
 893         } else {
 894                 callback(callback_arg, segments, nsegs,
 895                          m0->m_pkthdr.len, error);
 896         }
 897         bus_dma_tag_unlock(dmat);
 898         return error;
 899 }
 900
 901 int
 902 bus_dmamap_load_mbuf_segment(bus_dma_tag_t dmat, bus_dmamap_t map,
 903                              struct mbuf *m0,
 904                              bus_dma_segment_t *segs, int maxsegs,
 905                              int *nsegs, int flags)
 906 {
 907         int error;
 908
 909         M_ASSERTPKTHDR(m0);
 910
 911         KASSERT(maxsegs >= 1, ("invalid maxsegs %d", maxsegs));
 912         KASSERT(maxsegs <= dmat->nsegments,
 913                 ("%d too many segments, dmat only supports %d segments",
 914                  maxsegs, dmat->nsegments));
 915         KASSERT(flags & BUS_DMA_NOWAIT,
 916                 ("only BUS_DMA_NOWAIT is supported"));
 917
 918         if (m0->m_pkthdr.len <= dmat->maxsize) {
 919                 int first = 1;
 920                 vm_paddr_t lastaddr = 0;
 921                 struct mbuf *m;
 922
 923                 *nsegs = 1;
 924                 error = 0;
 925                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 926                         if (m->m_len == 0)
 927                                 continue;
 928
 929                         error = _bus_dmamap_load_buffer(dmat, map,
 930                                         m->m_data, m->m_len,
 931                                         segs, maxsegs,
 932                                         NULL, flags, &lastaddr,
 933                                         nsegs, first);
 934                         if (error == ENOMEM && !first) {
 935                                 /*
 936                                  * Out of bounce pages due to too many
 937                                  * fragments in the mbuf chain; return
 938                                  * EFBIG instead.
 939                                  */
 940                                 error = EFBIG;
 941                                 break;
 942                         }
 943                         first = 0;
 944                 }
 945 #ifdef INVARIANTS
 946                 if (!error)
 947                         KKASSERT(*nsegs <= maxsegs && *nsegs >= 1);
 948 #endif
 949         } else {
 950                 *nsegs = 0;
 951                 error = EINVAL;
 952         }
 953         KKASSERT(error != EINPROGRESS);
 954         return error;
 955 }
 956
 957 /*
 958  * Like _bus_dmamap_load(), but for uios.
 959  */
 960 int
 961 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 962                     struct uio *uio,
 963                     bus_dmamap_callback2_t *callback, void *callback_arg,
 964                     int flags)
 965 {
 966         vm_paddr_t lastaddr;
 967         int nsegs, error, first, i;
 968         bus_size_t resid;
 969         struct iovec *iov;
 970         pmap_t pmap;
 971         bus_dma_segment_t cache_segments[BUS_DMA_CACHE_SEGMENTS];
 972         bus_dma_segment_t *segments;
 973         bus_dma_segment_t *segs;
 974         int nsegs_left;
 975
 976         if (dmat->nsegments <= BUS_DMA_CACHE_SEGMENTS)
 977                 segments = cache_segments;
 978         else
 979                 segments = kmalloc(sizeof(bus_dma_segment_t) * dmat->nsegments,
 980                                    M_DEVBUF, M_WAITOK | M_ZERO);
 981
 982         /*
 983          * XXX
 984          * Follow old semantics.  Once all of the callers are fixed,
 985          * we should get rid of these internal flag "adjustment".
 986          */
 987         flags &= ~BUS_DMA_WAITOK;
 988         flags |= BUS_DMA_NOWAIT;
 989
 990         resid = (bus_size_t)uio->uio_resid;
 991         iov = uio->uio_iov;
 992
 993         segs = segments;
 994         nsegs_left = dmat->nsegments;
 995
 996         if (uio->uio_segflg == UIO_USERSPACE) {
 997                 struct thread *td;
 998
 999                 td = uio->uio_td;
1000                 KASSERT(td != NULL && td->td_proc != NULL,
1001                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
1002                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
1003         } else {
1004                 pmap = NULL;
1005         }
1006
1007         error = 0;
1008         nsegs = 1;
1009         first = 1;
1010         lastaddr = 0;
1011         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
1012                 /*
1013                  * Now at the first iovec to load.  Load each iovec
1014                  * until we have exhausted the residual count.
1015                  */
1016                 bus_size_t minlen =
1017                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
1018                 caddr_t addr = (caddr_t) iov[i].iov_base;
1019
1020                 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
1021                                 segs, nsegs_left,
1022                                 pmap, flags, &lastaddr, &nsegs, first);
1023                 first = 0;
1024
1025                 resid -= minlen;
1026                 if (error == 0) {
1027                         nsegs_left -= nsegs;
1028                         segs += nsegs;
1029                 }
1030         }
1031
1032         /*
1033          * Minimum one DMA segment, even if 0-length buffer.
1034          */
1035         if (nsegs_left == dmat->nsegments)
1036                 --nsegs_left;
1037
1038         if (error) {
1039                 /* force "no valid mappings" in callback */
1040                 callback(callback_arg, segments, 0,
1041                          0, error);
1042         } else {
1043                 callback(callback_arg, segments, dmat->nsegments - nsegs_left,
1044                          (bus_size_t)uio->uio_resid, error);
1045         }
1046         if (dmat->nsegments > BUS_DMA_CACHE_SEGMENTS)
1047                 kfree(segments, M_DEVBUF);
1048         return error;
1049 }
1050
1051 /*
1052  * Release the mapping held by map.
1053  */
1054 void
1055 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1056 {
1057         struct bounce_page *bpage;
1058
1059         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1060                 STAILQ_REMOVE_HEAD(&map->bpages, links);
1061                 free_bounce_page(dmat, bpage);
1062         }
1063 }
1064
1065 void
1066 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1067 {
1068         struct bounce_page *bpage;
1069
1070         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1071                 /*
1072                  * Handle data bouncing.  We might also
1073                  * want to add support for invalidating
1074                  * the caches on broken hardware
1075                  */
1076                 if (op & BUS_DMASYNC_PREWRITE) {
1077                         while (bpage != NULL) {
1078                                 bcopy((void *)bpage->datavaddr,
1079                                       (void *)bpage->vaddr,
1080                                       bpage->datacount);
1081                                 bpage = STAILQ_NEXT(bpage, links);
1082                         }
1083                         cpu_sfence();
1084                         dmat->bounce_zone->total_bounced++;
1085                 }
1086                 if (op & BUS_DMASYNC_POSTREAD) {
1087                         cpu_lfence();
1088                         while (bpage != NULL) {
1089                                 bcopy((void *)bpage->vaddr,
1090                                       (void *)bpage->datavaddr,
1091                                       bpage->datacount);
1092                                 bpage = STAILQ_NEXT(bpage, links);
1093                         }
1094                         dmat->bounce_zone->total_bounced++;
1095                 }
1096                 /* BUS_DMASYNC_PREREAD          - no operation on intel */
1097                 /* BUS_DMASYNC_POSTWRITE        - no operation on intel */
1098         }
1099 }
1100
1101 static int
1102 alloc_bounce_zone(bus_dma_tag_t dmat)
1103 {
1104         struct bounce_zone *bz, *new_bz;
1105
1106         KASSERT(dmat->bounce_zone == NULL,
1107                 ("bounce zone was already assigned"));
1108
1109         new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
1110
1111         lwkt_gettoken(&bounce_zone_tok);
1112
1113         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1114                 /*
1115                  * For shared bounce zone, check to see
1116                  * if we already have a suitable zone
1117                  */
1118                 STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1119                         if (dmat->alignment <= bz->alignment &&
1120                             dmat->lowaddr >= bz->lowaddr) {
1121                                 lwkt_reltoken(&bounce_zone_tok);
1122
1123                                 dmat->bounce_zone = bz;
1124                                 kfree(new_bz, M_DEVBUF);
1125                                 return 0;
1126                         }
1127                 }
1128         }
1129         bz = new_bz;
1130
1131         spin_init(&bz->spin, "allocbouncezone");
1132         STAILQ_INIT(&bz->bounce_page_list);
1133         STAILQ_INIT(&bz->bounce_map_waitinglist);
1134         bz->free_bpages = 0;
1135         bz->reserved_bpages = 0;
1136         bz->active_bpages = 0;
1137         bz->lowaddr = dmat->lowaddr;
1138         bz->alignment = round_page(dmat->alignment);
1139         ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1140
1141         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0) {
1142                 ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1143                 busdma_zonecount++;
1144                 STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1145         } else {
1146                 ksnprintf(bz->zoneid, 8, "zone%d", busdma_priv_zonecount);
1147                 busdma_priv_zonecount--;
1148         }
1149
1150         lwkt_reltoken(&bounce_zone_tok);
1151
1152         dmat->bounce_zone = bz;
1153
1154         sysctl_ctx_init(&bz->sysctl_ctx);
1155         bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
1156             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1157             CTLFLAG_RD, 0, "");
1158         if (bz->sysctl_tree == NULL) {
1159                 sysctl_ctx_free(&bz->sysctl_ctx);
1160                 return 0;       /* XXX error code? */
1161         }
1162
1163         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1164             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1165             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1166             "Total bounce pages");
1167         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1168             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1169             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1170             "Free bounce pages");
1171         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1172             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1173             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1174             "Reserved bounce pages");
1175         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1176             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1177             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1178             "Active bounce pages");
1179         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1180             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1181             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1182             "Total bounce requests");
1183         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1184             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1185             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1186             "Total bounce requests that were deferred");
1187         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1188             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1189             "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
1190             "Total bounce page reservations that were failed");
1191         SYSCTL_ADD_STRING(&bz->sysctl_ctx,
1192             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1193             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1194         SYSCTL_ADD_INT(&bz->sysctl_ctx,
1195             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
1196             "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1197
1198         return 0;
1199 }
1200
1201 static int
1202 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages, int flags)
1203 {
1204         struct bounce_zone *bz = dmat->bounce_zone;
1205         int count = 0, mflags;
1206
1207         if (flags & BUS_DMA_NOWAIT)
1208                 mflags = M_NOWAIT;
1209         else
1210                 mflags = M_WAITOK;
1211
1212         while (numpages > 0) {
1213                 struct bounce_page *bpage;
1214
1215                 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
1216
1217                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1218                                                          mflags, 0ul,
1219                                                          bz->lowaddr,
1220                                                          bz->alignment, 0);
1221                 if (bpage->vaddr == 0) {
1222                         kfree(bpage, M_DEVBUF);
1223                         break;
1224                 }
1225                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1226
1227                 BZ_LOCK(bz);
1228                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1229                 total_bounce_pages++;
1230                 bz->total_bpages++;
1231                 bz->free_bpages++;
1232                 BZ_UNLOCK(bz);
1233
1234                 count++;
1235                 numpages--;
1236         }
1237         return count;
1238 }
1239
1240 static void
1241 free_bounce_pages_all(bus_dma_tag_t dmat)
1242 {
1243         struct bounce_zone *bz = dmat->bounce_zone;
1244         struct bounce_page *bpage;
1245
1246         BZ_LOCK(bz);
1247
1248         while ((bpage = STAILQ_FIRST(&bz->bounce_page_list)) != NULL) {
1249                 STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1250
1251                 KKASSERT(total_bounce_pages > 0);
1252                 total_bounce_pages--;
1253
1254                 KKASSERT(bz->total_bpages > 0);
1255                 bz->total_bpages--;
1256
1257                 KKASSERT(bz->free_bpages > 0);
1258                 bz->free_bpages--;
1259
1260                 BZ_UNLOCK(bz);
1261                 contigfree((void *)bpage->vaddr, PAGE_SIZE, M_DEVBUF);
1262                 kfree(bpage, M_DEVBUF);
1263                 BZ_LOCK(bz);
1264         }
1265         if (bz->total_bpages) {
1266                 kprintf("#%d bounce pages are still in use\n",
1267                         bz->total_bpages);
1268                 print_backtrace(-1);
1269         }
1270
1271         BZ_UNLOCK(bz);
1272 }
1273
1274 static void
1275 free_bounce_zone(bus_dma_tag_t dmat)
1276 {
1277         struct bounce_zone *bz = dmat->bounce_zone;
1278
1279         if (bz == NULL)
1280                 return;
1281
1282         if ((dmat->flags & BUS_DMA_PRIVBZONE) == 0)
1283                 return;
1284
1285         free_bounce_pages_all(dmat);
1286         dmat->bounce_zone = NULL;
1287
1288         if (bz->sysctl_tree != NULL)
1289                 sysctl_ctx_free(&bz->sysctl_ctx);
1290         kfree(bz, M_DEVBUF);
1291 }
1292
1293 /* Assume caller holds bounce zone spinlock */
1294 static int
1295 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1296 {
1297         struct bounce_zone *bz = dmat->bounce_zone;
1298         int pages;
1299
1300         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1301         if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1302                 bz->reserve_failed++;
1303                 return (map->pagesneeded - (map->pagesreserved + pages));
1304         }
1305
1306         bz->free_bpages -= pages;
1307
1308         bz->reserved_bpages += pages;
1309         KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1310
1311         map->pagesreserved += pages;
1312         pages = map->pagesneeded - map->pagesreserved;
1313
1314         return pages;
1315 }
1316
1317 static void
1318 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1319 {
1320         struct bounce_zone *bz = dmat->bounce_zone;
1321         int reserved = map->pagesreserved;
1322         bus_dmamap_t wait_map;
1323
1324         map->pagesreserved = 0;
1325         map->pagesneeded = 0;
1326
1327         if (reserved == 0)
1328                 return;
1329
1330         BZ_LOCK(bz);
1331
1332         bz->free_bpages += reserved;
1333         KKASSERT(bz->free_bpages <= bz->total_bpages);
1334
1335         KKASSERT(bz->reserved_bpages >= reserved);
1336         bz->reserved_bpages -= reserved;
1337
1338         wait_map = get_map_waiting(dmat);
1339
1340         BZ_UNLOCK(bz);
1341
1342         if (wait_map != NULL)
1343                 add_map_callback(map);
1344 }
1345
1346 static bus_addr_t
1347 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1348                 bus_size_t *sizep)
1349 {
1350         struct bounce_zone *bz = dmat->bounce_zone;
1351         struct bounce_page *bpage;
1352         bus_size_t size;
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                 /*
1376                  * Page offset needs to be preserved.  No size adjustments
1377                  * needed.
1378                  */
1379                 bpage->vaddr |= vaddr & PAGE_MASK;
1380                 bpage->busaddr |= vaddr & PAGE_MASK;
1381                 size = *sizep;
1382         } else {
1383                 /*
1384                  * Realign to bounce page base address, reduce size if
1385                  * necessary.  Bounce pages are typically already
1386                  * page-aligned.
1387                  */
1388                 size = PAGE_SIZE - (bpage->busaddr & PAGE_MASK);
1389                 if (size < *sizep) {
1390                         *sizep = size;
1391                 } else {
1392                         size = *sizep;
1393                 }
1394         }
1395
1396         bpage->datavaddr = vaddr;
1397         bpage->datacount = size;
1398         STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1399         return bpage->busaddr;
1400 }
1401
1402 static void
1403 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1404 {
1405         struct bounce_zone *bz = dmat->bounce_zone;
1406         bus_dmamap_t map;
1407
1408         bpage->datavaddr = 0;
1409         bpage->datacount = 0;
1410
1411         if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1412                 /*
1413                  * Reset the bounce page to start at offset 0.  Other uses
1414                  * of this bounce page may need to store a full page of
1415                  * data and/or assume it starts on a page boundary.
1416                  */
1417                 bpage->vaddr &= ~PAGE_MASK;
1418                 bpage->busaddr &= ~PAGE_MASK;
1419         }
1420
1421         BZ_LOCK(bz);
1422
1423         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1424
1425         bz->free_bpages++;
1426         KKASSERT(bz->free_bpages <= bz->total_bpages);
1427
1428         KKASSERT(bz->active_bpages > 0);
1429         bz->active_bpages--;
1430
1431         map = get_map_waiting(dmat);
1432
1433         BZ_UNLOCK(bz);
1434
1435         if (map != NULL && map != (void *)-1)
1436                 add_map_callback(map);
1437 }
1438
1439 /* Assume caller holds bounce zone spinlock */
1440 static bus_dmamap_t
1441 get_map_waiting(bus_dma_tag_t dmat)
1442 {
1443         struct bounce_zone *bz = dmat->bounce_zone;
1444         bus_dmamap_t map;
1445
1446         map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1447         if (map != NULL && map != (void *)-1) {
1448                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1449                         STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1450                         bz->total_deferred++;
1451                 } else {
1452                         map = NULL;
1453                 }
1454         }
1455         return map;
1456 }
1457
1458 static void
1459 add_map_callback(bus_dmamap_t map)
1460 {
1461         spin_lock(&bounce_map_list_spin);
1462         STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1463         busdma_swi_pending = 1;
1464         setsoftvm();
1465         spin_unlock(&bounce_map_list_spin);
1466 }
1467
1468 void
1469 busdma_swi(void)
1470 {
1471         bus_dmamap_t map;
1472
1473         spin_lock(&bounce_map_list_spin);
1474         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1475                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1476                 spin_unlock(&bounce_map_list_spin);
1477                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1478                                 map->callback, map->callback_arg, /*flags*/0);
1479                 spin_lock(&bounce_map_list_spin);
1480         }
1481         spin_unlock(&bounce_map_list_spin);
1482 }
1483
1484 int
1485 bus_space_map(bus_space_tag_t t __unused, bus_addr_t addr, bus_size_t size,
1486     int flags __unused, bus_space_handle_t *bshp)
1487 {
1488
1489         if (t == X86_64_BUS_SPACE_MEM)
1490                 *bshp = (uintptr_t)pmap_mapdev(addr, size);
1491         else
1492                 *bshp = addr;
1493         return (0);
1494 }
1495
1496 void
1497 bus_space_unmap(bus_space_tag_t t, bus_space_handle_t bsh, bus_size_t size)
1498 {
1499         if (t == X86_64_BUS_SPACE_MEM)
1500                 pmap_unmapdev(bsh, size);
1501 }