sys/platform/pc32/i386/busdma_machdep.c

   1 /*
   2  * Copyright (c) 1997, 1998 Justin T. Gibbs.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions, and the following disclaimer,
  10  *    without modification, immediately at the beginning of the file.
  11  * 2. The name of the author may not be used to endorse or promote products
  12  *    derived from this software without specific prior written permission.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  18  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/sys/i386/i386/busdma_machdep.c,v 1.16.2.2 2003/01/23 00:55:27 scottl 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/thread2.h>
  36 #include <sys/bus_dma.h>
  37 #include <sys/kernel.h>
  38 #include <sys/sysctl.h>
  39 #include <sys/lock.h>
  40 #include <sys/spinlock2.h>
  41
  42 #include <vm/vm.h>
  43 #include <vm/vm_page.h>
  44
  45 /* XXX needed for to access pmap to convert per-proc virtual to physical */
  46 #include <sys/proc.h>
  47 #include <sys/lock.h>
  48 #include <vm/vm_map.h>
  49
  50 #include <machine/md_var.h>
  51
  52 #define MAX_BPAGES      1024
  53
  54 struct bounce_zone;
  55 struct bus_dmamap;
  56
  57 struct bus_dma_tag {
  58         bus_dma_tag_t   parent;
  59         bus_size_t      alignment;
  60         bus_size_t      boundary;
  61         bus_addr_t      lowaddr;
  62         bus_addr_t      highaddr;
  63         bus_dma_filter_t *filter;
  64         void            *filterarg;
  65         bus_size_t      maxsize;
  66         u_int           nsegments;
  67         bus_size_t      maxsegsz;
  68         int             flags;
  69         int             ref_count;
  70         int             map_count;
  71         bus_dma_segment_t *segments;
  72         struct bounce_zone *bounce_zone;
  73 };
  74
  75 /*
  76  * bus_dma_tag private flags
  77  */
  78 #define BUS_DMA_COULD_BOUNCE    BUS_DMA_BUS3
  79 #define BUS_DMA_MIN_ALLOC_COMP  BUS_DMA_BUS4
  80
  81 struct bounce_page {
  82         vm_offset_t     vaddr;          /* kva of bounce buffer */
  83         bus_addr_t      busaddr;        /* Physical address */
  84         vm_offset_t     datavaddr;      /* kva of client data */
  85         bus_size_t      datacount;      /* client data count */
  86         STAILQ_ENTRY(bounce_page) links;
  87 };
  88
  89 struct bounce_zone {
  90         STAILQ_ENTRY(bounce_zone) links;
  91         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  92         STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
  93 #ifdef SMP
  94         struct spinlock spin;
  95 #else
  96         int             unused0;
  97 #endif
  98         int             total_bpages;
  99         int             free_bpages;
 100         int             reserved_bpages;
 101         int             active_bpages;
 102         int             total_bounced;
 103         int             total_deferred;
 104         int             reserve_failed;
 105         bus_size_t      alignment;
 106         bus_size_t      boundary;
 107         bus_addr_t      lowaddr;
 108         char            zoneid[8];
 109         char            lowaddrid[20];
 110         struct sysctl_ctx_list sysctl_ctx;
 111         struct sysctl_oid *sysctl_tree;
 112 };
 113
 114 #ifdef SMP
 115 #define BZ_LOCK(bz)     spin_lock_wr(&(bz)->spin)
 116 #define BZ_UNLOCK(bz)   spin_unlock_wr(&(bz)->spin)
 117 #else
 118 #define BZ_LOCK(bz)     crit_enter()
 119 #define BZ_UNLOCK(bz)   crit_exit()
 120 #endif
 121
 122 static struct lwkt_token bounce_zone_tok =
 123         LWKT_TOKEN_INITIALIZER(bounce_zone_tok);
 124 static int busdma_zonecount;
 125 static STAILQ_HEAD(, bounce_zone) bounce_zone_list =
 126         STAILQ_HEAD_INITIALIZER(bounce_zone_list);
 127
 128 int busdma_swi_pending;
 129 static int total_bounce_pages;
 130 static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
 131
 132 struct bus_dmamap {
 133         struct bp_list  bpages;
 134         int             pagesneeded;
 135         int             pagesreserved;
 136         bus_dma_tag_t   dmat;
 137         void            *buf;           /* unmapped buffer pointer */
 138         bus_size_t      buflen;         /* unmapped buffer length */
 139         bus_dmamap_callback_t *callback;
 140         void            *callback_arg;
 141         STAILQ_ENTRY(bus_dmamap) links;
 142 };
 143
 144 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist =
 145         STAILQ_HEAD_INITIALIZER(bounce_map_callbacklist);
 146
 147 static struct bus_dmamap nobounce_dmamap;
 148
 149 static int              alloc_bounce_zone(bus_dma_tag_t);
 150 static int              alloc_bounce_pages(bus_dma_tag_t, u_int);
 151 static int              reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t, int);
 152 static void             return_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
 153 static bus_addr_t       add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
 154                             vm_offset_t, bus_size_t);
 155 static void             free_bounce_page(bus_dma_tag_t, struct bounce_page *);
 156
 157 static bus_dmamap_t     get_map_waiting(bus_dma_tag_t);
 158 static void             add_map_callback(bus_dmamap_t);
 159
 160 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 161 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bounce_pages,
 162            0, "Total bounce pages");
 163
 164 static __inline int
 165 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 166 {
 167         int retval;
 168
 169         retval = 0;
 170         do {
 171                 if (paddr > dmat->lowaddr
 172                  && paddr <= dmat->highaddr
 173                  && (dmat->filter == NULL
 174                   || (*dmat->filter)(dmat->filterarg, paddr) != 0))
 175                         retval = 1;
 176
 177                 dmat = dmat->parent;
 178         } while (retval == 0 && dmat != NULL);
 179         return (retval);
 180 }
 181
 182 /*
 183  * Allocate a device specific dma_tag.
 184  */
 185 int
 186 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 187                    bus_size_t boundary, bus_addr_t lowaddr,
 188                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 189                    void *filterarg, bus_size_t maxsize, int nsegments,
 190                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 191 {
 192         bus_dma_tag_t newtag;
 193         int error = 0;
 194
 195         if (alignment == 0)
 196                 alignment = 1;
 197
 198         /* Return a NULL tag on failure */
 199         *dmat = NULL;
 200
 201         newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
 202
 203         newtag->parent = parent;
 204         newtag->alignment = alignment;
 205         newtag->boundary = boundary;
 206         newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 207         newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
 208         newtag->filter = filter;
 209         newtag->filterarg = filterarg;
 210         newtag->maxsize = maxsize;
 211         newtag->nsegments = nsegments;
 212         newtag->maxsegsz = maxsegsz;
 213         newtag->flags = flags;
 214         newtag->ref_count = 1; /* Count ourself */
 215         newtag->map_count = 0;
 216         newtag->segments = NULL;
 217         newtag->bounce_zone = NULL;
 218
 219         /* Take into account any restrictions imposed by our parent tag */
 220         if (parent != NULL) {
 221                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 222                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 223
 224                 if (newtag->boundary == 0) {
 225                         newtag->boundary = parent->boundary;
 226                 } else if (parent->boundary != 0) {
 227                         newtag->boundary = MIN(parent->boundary,
 228                                                newtag->boundary);
 229                 }
 230
 231 #ifdef notyet
 232                 newtag->alignment = MAX(parent->alignment, newtag->alignment);
 233 #endif
 234
 235                 if (newtag->filter == NULL) {
 236                         /*
 237                          * Short circuit looking at our parent directly
 238                          * since we have encapsulated all of its information
 239                          */
 240                         newtag->filter = parent->filter;
 241                         newtag->filterarg = parent->filterarg;
 242                         newtag->parent = parent->parent;
 243                 }
 244                 if (newtag->parent != NULL)
 245                         parent->ref_count++;
 246         }
 247
 248         if (newtag->lowaddr < ptoa(Maxmem))
 249                 newtag->flags |= BUS_DMA_COULD_BOUNCE;
 250
 251         if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
 252             (flags & BUS_DMA_ALLOCNOW) != 0) {
 253                 struct bounce_zone *bz;
 254
 255                 /* Must bounce */
 256
 257                 if (lowaddr > bounce_lowaddr) {
 258                         /*
 259                          * Go through the pool and kill any pages
 260                          * that don't reside below lowaddr.
 261                          */
 262                         panic("bus_dma_tag_create: page reallocation "
 263                               "not implemented");
 264                 }
 265
 266                 error = alloc_bounce_zone(newtag);
 267                 if (error)
 268                         goto back;
 269                 bz = newtag->bounce_zone;
 270
 271                 if (ptoa(bz->total_bpages) < maxsize) {
 272                         int pages;
 273
 274                         pages = atop(maxsize) - bz->total_bpages;
 275
 276                         /* Add pages to our bounce pool */
 277                         if (alloc_bounce_pages(newtag, pages) < pages)
 278                                 error = ENOMEM;
 279                 }
 280                 /* Performed initial allocation */
 281                 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 282         }
 283 back:
 284         if (error)
 285                 kfree(newtag, M_DEVBUF);
 286         else
 287                 *dmat = newtag;
 288         return error;
 289 }
 290
 291 int
 292 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 293 {
 294         if (dmat != NULL) {
 295                 if (dmat->map_count != 0)
 296                         return (EBUSY);
 297
 298                 while (dmat != NULL) {
 299                         bus_dma_tag_t parent;
 300
 301                         parent = dmat->parent;
 302                         dmat->ref_count--;
 303                         if (dmat->ref_count == 0) {
 304                                 if (dmat->segments != NULL)
 305                                         kfree(dmat->segments, M_DEVBUF);
 306                                 kfree(dmat, M_DEVBUF);
 307                                 /*
 308                                  * Last reference count, so
 309                                  * release our reference
 310                                  * count on our parent.
 311                                  */
 312                                 dmat = parent;
 313                         } else
 314                                 dmat = NULL;
 315                 }
 316         }
 317         return (0);
 318 }
 319
 320 /*
 321  * Allocate a handle for mapping from kva/uva/physical
 322  * address space into bus device space.
 323  */
 324 int
 325 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 326 {
 327         int error;
 328
 329         error = 0;
 330
 331         if (dmat->segments == NULL) {
 332                 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
 333                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 334                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 335         }
 336
 337         if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
 338                 struct bounce_zone *bz;
 339                 int maxpages;
 340
 341                 /* Must bounce */
 342
 343                 if (dmat->bounce_zone == NULL) {
 344                         error = alloc_bounce_zone(dmat);
 345                         if (error)
 346                                 return error;
 347                 }
 348                 bz = dmat->bounce_zone;
 349
 350                 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
 351
 352                 /* Initialize the new map */
 353                 STAILQ_INIT(&((*mapp)->bpages));
 354                 /*
 355                  * Attempt to add pages to our pool on a per-instance
 356                  * basis up to a sane limit.
 357                  */
 358                 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
 359                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
 360                  || (dmat->map_count > 0
 361                   && bz->total_bpages < maxpages)) {
 362                         int pages;
 363
 364                         if (dmat->lowaddr > bounce_lowaddr) {
 365                                 /*
 366                                  * Go through the pool and kill any pages
 367                                  * that don't reside below lowaddr.
 368                                  */
 369                                 panic("bus_dmamap_create: page reallocation "
 370                                       "not implemented");
 371                         }
 372
 373                         pages = MAX(atop(dmat->maxsize), 1);
 374                         pages = MIN(maxpages - bz->total_bpages, pages);
 375                         pages = MAX(pages, 1);
 376                         if (alloc_bounce_pages(dmat, pages) < pages)
 377                                 error = ENOMEM;
 378
 379                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 380                                 if (!error)
 381                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 382                         } else {
 383                                 error = 0;
 384                         }
 385                 }
 386         } else {
 387                 *mapp = NULL;
 388         }
 389         if (!error)
 390                 dmat->map_count++;
 391         return error;
 392 }
 393
 394 /*
 395  * Destroy a handle for mapping from kva/uva/physical
 396  * address space into bus device space.
 397  */
 398 int
 399 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 400 {
 401         if (map != NULL) {
 402                 if (STAILQ_FIRST(&map->bpages) != NULL)
 403                         return (EBUSY);
 404                 kfree(map, M_DEVBUF);
 405         }
 406         dmat->map_count--;
 407         return (0);
 408 }
 409
 410 /*
 411  * Allocate a piece of memory that can be efficiently mapped into
 412  * bus device space based on the constraints lited in the dma tag.
 413  *
 414  * mapp is degenerate.  By definition this allocation should not require
 415  * bounce buffers so do not allocate a dma map.
 416  */
 417 int
 418 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 419                  bus_dmamap_t *mapp)
 420 {
 421         int mflags;
 422
 423         /* If we succeed, no mapping/bouncing will be required */
 424         *mapp = NULL;
 425
 426         if (dmat->segments == NULL) {
 427                 KKASSERT(dmat->nsegments < 16384);
 428                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 429                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 430         }
 431
 432         if (flags & BUS_DMA_NOWAIT)
 433                 mflags = M_NOWAIT;
 434         else
 435                 mflags = M_WAITOK;
 436         if (flags & BUS_DMA_ZERO)
 437                 mflags |= M_ZERO;
 438
 439         if ((dmat->maxsize <= PAGE_SIZE) &&
 440             dmat->lowaddr >= ptoa(Maxmem)) {
 441                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 442                 /*
 443                  * XXX Check whether the allocation crossed a page boundary
 444                  * and retry with power-of-2 alignment in that case.
 445                  */
 446                 if ((((intptr_t)*vaddr) & PAGE_MASK) !=
 447                     (((intptr_t)*vaddr + dmat->maxsize) & PAGE_MASK)) {
 448                         size_t size;
 449
 450                         kfree(*vaddr, M_DEVBUF);
 451                         /* XXX check for overflow? */
 452                         for (size = 1; size <= dmat->maxsize; size <<= 1)
 453                                 ;
 454                         *vaddr = kmalloc(size, M_DEVBUF, mflags);
 455                 }
 456         } else {
 457                 /*
 458                  * XXX Use Contigmalloc until it is merged into this facility
 459                  *     and handles multi-seg allocations.  Nobody is doing
 460                  *     multi-seg allocations yet though.
 461                  */
 462                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 463                     0ul, dmat->lowaddr, dmat->alignment, dmat->boundary);
 464         }
 465         if (*vaddr == NULL)
 466                 return (ENOMEM);
 467         return (0);
 468 }
 469
 470 /*
 471  * Free a piece of memory and it's allociated dmamap, that was allocated
 472  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 473  */
 474 void
 475 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 476 {
 477         /*
 478          * dmamem does not need to be bounced, so the map should be
 479          * NULL
 480          */
 481         if (map != NULL)
 482                 panic("bus_dmamem_free: Invalid map freed\n");
 483         if ((dmat->maxsize <= PAGE_SIZE) &&
 484             dmat->lowaddr >= ptoa(Maxmem))
 485                 kfree(vaddr, M_DEVBUF);
 486         else
 487                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 488 }
 489
 490 static __inline vm_paddr_t
 491 _bus_dma_extract(pmap_t pmap, vm_offset_t vaddr)
 492 {
 493         if (pmap)
 494                 return pmap_extract(pmap, vaddr);
 495         else
 496                 return pmap_kextract(vaddr);
 497 }
 498
 499 /*
 500  * Utility function to load a linear buffer.  lastaddrp holds state
 501  * between invocations (for multiple-buffer loads).  segp contains
 502  * the segment following the starting one on entrace, and the ending
 503  * segment on exit.  first indicates if this is the first invocation
 504  * of this function.
 505  */
 506 static int
 507 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 508                         bus_dmamap_t map,
 509                         void *buf, bus_size_t buflen,
 510                         pmap_t pmap,
 511                         int flags,
 512                         vm_paddr_t *lastpaddrp,
 513                         int *segp,
 514                         int first)
 515 {
 516         vm_offset_t vaddr;
 517         vm_paddr_t paddr, nextpaddr;
 518         bus_dma_segment_t *sg;
 519         bus_addr_t bmask;
 520         int seg, error = 0;
 521
 522         if (map == NULL)
 523                 map = &nobounce_dmamap;
 524
 525         /*
 526          * If we are being called during a callback, pagesneeded will
 527          * be non-zero, so we can avoid doing the work twice.
 528          */
 529         if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 530             map != &nobounce_dmamap && map->pagesneeded == 0) {
 531                 vm_offset_t vendaddr;
 532
 533                 /*
 534                  * Count the number of bounce pages
 535                  * needed in order to complete this transfer
 536                  */
 537                 vaddr = (vm_offset_t)buf;
 538                 vendaddr = (vm_offset_t)buf + buflen;
 539
 540                 while (vaddr < vendaddr) {
 541                         paddr = _bus_dma_extract(pmap, vaddr);
 542                         if (run_filter(dmat, paddr) != 0)
 543                                 map->pagesneeded++;
 544                         vaddr += (PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK));
 545                 }
 546         }
 547
 548         /* Reserve Necessary Bounce Pages */
 549         if (map->pagesneeded != 0) {
 550                 struct bounce_zone *bz;
 551
 552                 bz = dmat->bounce_zone;
 553                 BZ_LOCK(bz);
 554                 if (flags & BUS_DMA_NOWAIT) {
 555                         if (reserve_bounce_pages(dmat, map, 0) != 0) {
 556                                 BZ_UNLOCK(bz);
 557                                 return (ENOMEM);
 558                         }
 559                 } else {
 560                         if (reserve_bounce_pages(dmat, map, 1) != 0) {
 561                                 /* Queue us for resources */
 562                                 map->dmat = dmat;
 563                                 map->buf = buf;
 564                                 map->buflen = buflen;
 565
 566                                 STAILQ_INSERT_TAIL(
 567                                     &dmat->bounce_zone->bounce_map_waitinglist,
 568                                     map, links);
 569                                 BZ_UNLOCK(bz);
 570
 571                                 return (EINPROGRESS);
 572                         }
 573                 }
 574                 BZ_UNLOCK(bz);
 575         }
 576
 577         KKASSERT(*segp >= 1 && *segp <= dmat->nsegments);
 578         seg = *segp;
 579         sg = &dmat->segments[seg - 1];
 580
 581         vaddr = (vm_offset_t)buf;
 582         nextpaddr = *lastpaddrp;
 583         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 584
 585         /* force at least one segment */
 586         do {
 587                 bus_size_t size;
 588
 589                 /*
 590                  * Per-page main loop
 591                  */
 592                 paddr = _bus_dma_extract(pmap, vaddr);
 593                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 594                 if (size > buflen)
 595                         size = buflen;
 596                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 597                         /*
 598                          * note: this paddr has the same in-page offset
 599                          * as vaddr and thus the paddr above, so the
 600                          * size does not have to be recalculated
 601                          */
 602                         paddr = add_bounce_page(dmat, map, vaddr, size);
 603                 }
 604
 605                 /*
 606                  * Fill in the bus_dma_segment
 607                  */
 608                 if (first) {
 609                         sg->ds_addr = paddr;
 610                         sg->ds_len = size;
 611                         first = 0;
 612                 } else if (paddr == nextpaddr) {
 613                         sg->ds_len += size;
 614                 } else {
 615                         sg++;
 616                         seg++;
 617                         if (seg > dmat->nsegments)
 618                                 break;
 619                         sg->ds_addr = paddr;
 620                         sg->ds_len = size;
 621                 }
 622                 nextpaddr = paddr + size;
 623
 624                 /*
 625                  * Handle maxsegsz and boundary issues with a nested loop
 626                  */
 627                 for (;;) {
 628                         bus_size_t tmpsize;
 629
 630                         /*
 631                          * Limit to the boundary and maximum segment size
 632                          */
 633                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 634                                 tmpsize = dmat->boundary -
 635                                           (sg->ds_addr & ~bmask);
 636                                 if (tmpsize > dmat->maxsegsz)
 637                                         tmpsize = dmat->maxsegsz;
 638                                 KKASSERT(tmpsize < sg->ds_len);
 639                         } else if (sg->ds_len > dmat->maxsegsz) {
 640                                 tmpsize = dmat->maxsegsz;
 641                         } else {
 642                                 break;
 643                         }
 644
 645                         /*
 646                          * Futz, split the data into a new segment.
 647                          */
 648                         if (seg >= dmat->nsegments)
 649                                 goto fail;
 650                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 651                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 652                         sg[0].ds_len = tmpsize;
 653                         sg++;
 654                         seg++;
 655                 }
 656
 657                 /*
 658                  * Adjust for loop
 659                  */
 660                 buflen -= size;
 661                 vaddr += size;
 662         } while (buflen > 0);
 663 fail:
 664         if (buflen != 0)
 665                 error = EFBIG;
 666
 667         *segp = seg;
 668         *lastpaddrp = nextpaddr;
 669
 670         if (error && (dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 671             map != &nobounce_dmamap) {
 672                 _bus_dmamap_unload(dmat, map);
 673                 return_bounce_pages(dmat, map);
 674         }
 675         return error;
 676 }
 677
 678 /*
 679  * Map the buffer buf into bus space using the dmamap map.
 680  */
 681 int
 682 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 683                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 684                 void *callback_arg, int flags)
 685 {
 686         vm_paddr_t lastaddr = 0;
 687         int error, nsegs = 1;
 688
 689         if (map != NULL) {
 690                 /*
 691                  * XXX
 692                  * Follow old semantics.  Once all of the callers are fixed,
 693                  * we should get rid of these internal flag "adjustment".
 694                  */
 695                 flags &= ~BUS_DMA_NOWAIT;
 696                 flags |= BUS_DMA_WAITOK;
 697
 698                 map->callback = callback;
 699                 map->callback_arg = callback_arg;
 700         }
 701
 702         error = _bus_dmamap_load_buffer(dmat, map, buf, buflen,
 703                         NULL, flags, &lastaddr, &nsegs, 1);
 704         if (error == EINPROGRESS)
 705                 return error;
 706
 707         callback(callback_arg, dmat->segments, nsegs, error);
 708         return 0;
 709 }
 710
 711 /*
 712  * Like _bus_dmamap_load(), but for mbufs.
 713  */
 714 int
 715 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 716                      struct mbuf *m0,
 717                      bus_dmamap_callback2_t *callback, void *callback_arg,
 718                      int flags)
 719 {
 720         int nsegs, error;
 721
 722         M_ASSERTPKTHDR(m0);
 723
 724         /*
 725          * XXX
 726          * Follow old semantics.  Once all of the callers are fixed,
 727          * we should get rid of these internal flag "adjustment".
 728          */
 729         flags &= ~BUS_DMA_WAITOK;
 730         flags |= BUS_DMA_NOWAIT;
 731
 732         if (m0->m_pkthdr.len <= dmat->maxsize) {
 733                 int first = 1;
 734                 vm_paddr_t lastaddr = 0;
 735                 struct mbuf *m;
 736
 737                 nsegs = 1;
 738                 error = 0;
 739                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 740                         if (m->m_len == 0)
 741                                 continue;
 742
 743                         error = _bus_dmamap_load_buffer(dmat, map,
 744                                         m->m_data, m->m_len,
 745                                         NULL, flags, &lastaddr,
 746                                         &nsegs, first);
 747                         first = 0;
 748                 }
 749         } else {
 750                 nsegs = 0;
 751                 error = EINVAL;
 752         }
 753
 754         if (error) {
 755                 /* force "no valid mappings" in callback */
 756                 callback(callback_arg, dmat->segments, 0, 0, error);
 757         } else {
 758                 callback(callback_arg, dmat->segments, nsegs,
 759                          m0->m_pkthdr.len, error);
 760         }
 761         return error;
 762 }
 763
 764 /*
 765  * Like _bus_dmamap_load(), but for uios.
 766  */
 767 int
 768 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 769                     struct uio *uio,
 770                     bus_dmamap_callback2_t *callback, void *callback_arg,
 771                     int flags)
 772 {
 773         vm_paddr_t lastaddr;
 774         int nsegs, error, first, i;
 775         bus_size_t resid;
 776         struct iovec *iov;
 777         pmap_t pmap;
 778
 779         /*
 780          * XXX
 781          * Follow old semantics.  Once all of the callers are fixed,
 782          * we should get rid of these internal flag "adjustment".
 783          */
 784         flags &= ~BUS_DMA_WAITOK;
 785         flags |= BUS_DMA_NOWAIT;
 786
 787         resid = uio->uio_resid;
 788         iov = uio->uio_iov;
 789
 790         if (uio->uio_segflg == UIO_USERSPACE) {
 791                 struct thread *td;
 792
 793                 td = uio->uio_td;
 794                 KASSERT(td != NULL && td->td_proc != NULL,
 795                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 796                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 797         } else {
 798                 pmap = NULL;
 799         }
 800
 801         error = 0;
 802         nsegs = 1;
 803         first = 1;
 804         lastaddr = 0;
 805         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 806                 /*
 807                  * Now at the first iovec to load.  Load each iovec
 808                  * until we have exhausted the residual count.
 809                  */
 810                 bus_size_t minlen =
 811                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 812                 caddr_t addr = (caddr_t) iov[i].iov_base;
 813
 814                 error = _bus_dmamap_load_buffer(dmat, map, addr, minlen,
 815                                 pmap, flags, &lastaddr, &nsegs, first);
 816                 first = 0;
 817
 818                 resid -= minlen;
 819         }
 820
 821         if (error) {
 822                 /* force "no valid mappings" in callback */
 823                 callback(callback_arg, dmat->segments, 0, 0, error);
 824         } else {
 825                 callback(callback_arg, dmat->segments, nsegs,
 826                          uio->uio_resid, error);
 827         }
 828         return error;
 829 }
 830
 831 /*
 832  * Release the mapping held by map.
 833  */
 834 void
 835 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 836 {
 837         struct bounce_page *bpage;
 838
 839         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 840                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 841                 free_bounce_page(dmat, bpage);
 842         }
 843 }
 844
 845 void
 846 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 847 {
 848         struct bounce_page *bpage;
 849
 850         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 851                 /*
 852                  * Handle data bouncing.  We might also
 853                  * want to add support for invalidating
 854                  * the caches on broken hardware
 855                  */
 856                 switch (op) {
 857                 case BUS_DMASYNC_PREWRITE:
 858                         while (bpage != NULL) {
 859                                 bcopy((void *)bpage->datavaddr,
 860                                       (void *)bpage->vaddr,
 861                                       bpage->datacount);
 862                                 bpage = STAILQ_NEXT(bpage, links);
 863                         }
 864                         dmat->bounce_zone->total_bounced++;
 865                         break;
 866
 867                 case BUS_DMASYNC_POSTREAD:
 868                         while (bpage != NULL) {
 869                                 bcopy((void *)bpage->vaddr,
 870                                       (void *)bpage->datavaddr,
 871                                       bpage->datacount);
 872                                 bpage = STAILQ_NEXT(bpage, links);
 873                         }
 874                         dmat->bounce_zone->total_bounced++;
 875                         break;
 876
 877                 case BUS_DMASYNC_PREREAD:
 878                 case BUS_DMASYNC_POSTWRITE:
 879                         /* No-ops */
 880                         break;
 881                 }
 882         }
 883 }
 884
 885 static int
 886 alloc_bounce_zone(bus_dma_tag_t dmat)
 887 {
 888         struct bounce_zone *bz, *new_bz;
 889         lwkt_tokref ref;
 890
 891         KASSERT(dmat->bounce_zone == NULL,
 892                 ("bounce zone was already assigned\n"));
 893
 894         new_bz = kmalloc(sizeof(*new_bz), M_DEVBUF, M_INTWAIT | M_ZERO);
 895
 896         lwkt_gettoken(&ref, &bounce_zone_tok);
 897
 898         /* Check to see if we already have a suitable zone */
 899         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
 900                 if (dmat->alignment <= bz->alignment &&
 901                     dmat->boundary <= bz->boundary &&
 902                     dmat->lowaddr >= bz->lowaddr) {
 903                         lwkt_reltoken(&ref);
 904
 905                         dmat->bounce_zone = bz;
 906                         kfree(new_bz, M_DEVBUF);
 907                         return 0;
 908                 }
 909         }
 910         bz = new_bz;
 911
 912 #ifdef SMP
 913         spin_init(&bz->spin);
 914 #endif
 915         STAILQ_INIT(&bz->bounce_page_list);
 916         STAILQ_INIT(&bz->bounce_map_waitinglist);
 917         bz->free_bpages = 0;
 918         bz->reserved_bpages = 0;
 919         bz->active_bpages = 0;
 920         bz->lowaddr = dmat->lowaddr;
 921         bz->alignment = dmat->alignment;
 922         bz->boundary = dmat->boundary;
 923         ksnprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
 924         busdma_zonecount++;
 925         ksnprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
 926         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
 927
 928         lwkt_reltoken(&ref);
 929
 930         dmat->bounce_zone = bz;
 931
 932         sysctl_ctx_init(&bz->sysctl_ctx);
 933         bz->sysctl_tree = SYSCTL_ADD_NODE(&bz->sysctl_ctx,
 934             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
 935             CTLFLAG_RD, 0, "");
 936         if (bz->sysctl_tree == NULL) {
 937                 sysctl_ctx_free(&bz->sysctl_ctx);
 938                 return 0;       /* XXX error code? */
 939         }
 940
 941         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 942             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 943             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
 944             "Total bounce pages");
 945         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 946             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 947             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
 948             "Free bounce pages");
 949         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 950             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 951             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
 952             "Reserved bounce pages");
 953         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 954             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 955             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
 956             "Active bounce pages");
 957         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 958             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 959             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
 960             "Total bounce requests");
 961         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 962             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 963             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
 964             "Total bounce requests that were deferred");
 965         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 966             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 967             "reserve_failed", CTLFLAG_RD, &bz->reserve_failed, 0,
 968             "Total bounce page reservations that were failed");
 969         SYSCTL_ADD_STRING(&bz->sysctl_ctx,
 970             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 971             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
 972         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 973             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 974             "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
 975         SYSCTL_ADD_INT(&bz->sysctl_ctx,
 976             SYSCTL_CHILDREN(bz->sysctl_tree), OID_AUTO,
 977             "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
 978
 979         return 0;
 980 }
 981
 982 static int
 983 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 984 {
 985         struct bounce_zone *bz = dmat->bounce_zone;
 986         int count = 0;
 987
 988         while (numpages > 0) {
 989                 struct bounce_page *bpage;
 990
 991                 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
 992
 993                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 994                                                          M_NOWAIT, 0ul,
 995                                                          dmat->lowaddr,
 996                                                          PAGE_SIZE,
 997                                                          0);
 998                 if (bpage->vaddr == 0) {
 999                         kfree(bpage, M_DEVBUF);
1000                         break;
1001                 }
1002                 bpage->busaddr = pmap_kextract(bpage->vaddr);
1003
1004                 BZ_LOCK(bz);
1005                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1006                 total_bounce_pages++;
1007                 bz->total_bpages++;
1008                 bz->free_bpages++;
1009                 BZ_UNLOCK(bz);
1010
1011                 count++;
1012                 numpages--;
1013         }
1014         return count;
1015 }
1016
1017 /* Assume caller holds bounce zone spinlock */
1018 static int
1019 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1020 {
1021         struct bounce_zone *bz = dmat->bounce_zone;
1022         int pages;
1023
1024         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1025         if (!commit && map->pagesneeded > (map->pagesreserved + pages)) {
1026                 bz->reserve_failed++;
1027                 return (map->pagesneeded - (map->pagesreserved + pages));
1028         }
1029
1030         bz->free_bpages -= pages;
1031
1032         bz->reserved_bpages += pages;
1033         KKASSERT(bz->reserved_bpages <= bz->total_bpages);
1034
1035         map->pagesreserved += pages;
1036         pages = map->pagesneeded - map->pagesreserved;
1037
1038         return pages;
1039 }
1040
1041 static void
1042 return_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
1043 {
1044         struct bounce_zone *bz = dmat->bounce_zone;
1045         int reserved = map->pagesreserved;
1046         bus_dmamap_t wait_map;
1047
1048         map->pagesreserved = 0;
1049         map->pagesneeded = 0;
1050
1051         if (reserved == 0)
1052                 return;
1053
1054         BZ_LOCK(bz);
1055
1056         bz->free_bpages += reserved;
1057         KKASSERT(bz->free_bpages <= bz->total_bpages);
1058
1059         KKASSERT(bz->reserved_bpages >= reserved);
1060         bz->reserved_bpages -= reserved;
1061
1062         wait_map = get_map_waiting(dmat);
1063
1064         BZ_UNLOCK(bz);
1065
1066         if (wait_map != NULL)
1067                 add_map_callback(map);
1068 }
1069
1070 static bus_addr_t
1071 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1072                 bus_size_t size)
1073 {
1074         struct bounce_zone *bz = dmat->bounce_zone;
1075         struct bounce_page *bpage;
1076
1077         KASSERT(map->pagesneeded > 0, ("map doesn't need any pages"));
1078         map->pagesneeded--;
1079
1080         KASSERT(map->pagesreserved > 0, ("map doesn't reserve any pages"));
1081         map->pagesreserved--;
1082
1083         BZ_LOCK(bz);
1084
1085         bpage = STAILQ_FIRST(&bz->bounce_page_list);
1086         KASSERT(bpage != NULL, ("free page list is empty"));
1087         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1088
1089         KKASSERT(bz->reserved_bpages > 0);
1090         bz->reserved_bpages--;
1091
1092         bz->active_bpages++;
1093         KKASSERT(bz->active_bpages <= bz->total_bpages);
1094
1095         BZ_UNLOCK(bz);
1096
1097         bpage->datavaddr = vaddr;
1098         bpage->datacount = size;
1099         STAILQ_INSERT_TAIL(&map->bpages, bpage, links);
1100         return bpage->busaddr;
1101 }
1102
1103 static void
1104 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1105 {
1106         struct bounce_zone *bz = dmat->bounce_zone;
1107         bus_dmamap_t map;
1108
1109         bpage->datavaddr = 0;
1110         bpage->datacount = 0;
1111
1112         BZ_LOCK(bz);
1113
1114         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1115
1116         bz->free_bpages++;
1117         KKASSERT(bz->free_bpages <= bz->total_bpages);
1118
1119         KKASSERT(bz->active_bpages > 0);
1120         bz->active_bpages--;
1121
1122         map = get_map_waiting(dmat);
1123
1124         BZ_UNLOCK(bz);
1125
1126         if (map != NULL)
1127                 add_map_callback(map);
1128 }
1129
1130 /* Assume caller holds bounce zone spinlock */
1131 static bus_dmamap_t
1132 get_map_waiting(bus_dma_tag_t dmat)
1133 {
1134         struct bounce_zone *bz = dmat->bounce_zone;
1135         bus_dmamap_t map;
1136
1137         map = STAILQ_FIRST(&bz->bounce_map_waitinglist);
1138         if (map != NULL) {
1139                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1140                         STAILQ_REMOVE_HEAD(&bz->bounce_map_waitinglist, links);
1141                         bz->total_deferred++;
1142                 } else {
1143                         map = NULL;
1144                 }
1145         }
1146         return map;
1147 }
1148
1149 static void
1150 add_map_callback(bus_dmamap_t map)
1151 {
1152         /* XXX callbacklist is not MPSAFE */
1153         crit_enter();
1154         get_mplock();
1155         STAILQ_INSERT_TAIL(&bounce_map_callbacklist, map, links);
1156         busdma_swi_pending = 1;
1157         setsoftvm();
1158         rel_mplock();
1159         crit_exit();
1160 }
1161
1162 void
1163 busdma_swi(void)
1164 {
1165         bus_dmamap_t map;
1166
1167         crit_enter();
1168         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1169                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1170                 crit_exit();
1171                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1172                                 map->callback, map->callback_arg, /*flags*/0);
1173                 crit_enter();
1174         }
1175         crit_exit();
1176 }