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