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
  40 #include <vm/vm.h>
  41 #include <vm/vm_page.h>
  42
  43 /* XXX needed for to access pmap to convert per-proc virtual to physical */
  44 #include <sys/proc.h>
  45 #include <sys/lock.h>
  46 #include <vm/vm_map.h>
  47
  48 #include <machine/md_var.h>
  49
  50 #define MAX_BPAGES 1024
  51
  52 struct bus_dma_tag {
  53         bus_dma_tag_t     parent;
  54         bus_size_t        alignment;
  55         bus_size_t        boundary;
  56         bus_addr_t        lowaddr;
  57         bus_addr_t        highaddr;
  58         bus_dma_filter_t *filter;
  59         void             *filterarg;
  60         bus_size_t        maxsize;
  61         u_int             nsegments;
  62         bus_size_t        maxsegsz;
  63         int               flags;
  64         int               ref_count;
  65         int               map_count;
  66         bus_dma_segment_t *segments;
  67 };
  68
  69 struct bounce_page {
  70         vm_offset_t     vaddr;          /* kva of bounce buffer */
  71         bus_addr_t      busaddr;        /* Physical address */
  72         vm_offset_t     datavaddr;      /* kva of client data */
  73         bus_size_t      datacount;      /* client data count */
  74         STAILQ_ENTRY(bounce_page) links;
  75 };
  76
  77 int busdma_swi_pending;
  78
  79 static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  80 static int free_bpages;
  81 static int reserved_bpages;
  82 static int active_bpages;
  83 static int total_bpages;
  84 static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
  85
  86 struct bus_dmamap {
  87         struct bp_list         bpages;
  88         int                    pagesneeded;
  89         int                    pagesreserved;
  90         bus_dma_tag_t          dmat;
  91         void                  *buf;             /* unmapped buffer pointer */
  92         bus_size_t             buflen;          /* unmapped buffer length */
  93         bus_dmamap_callback_t *callback;
  94         void                  *callback_arg;
  95         STAILQ_ENTRY(bus_dmamap) links;
  96 };
  97
  98 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
  99 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 100 static struct bus_dmamap nobounce_dmamap;
 101
 102 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 103 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map);
 104 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 105                                    vm_offset_t vaddr, bus_size_t size);
 106 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 107 static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 108
 109 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 110 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 111            "Total bounce pages");
 112
 113 static __inline int
 114 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 115 {
 116         int retval;
 117
 118         retval = 0;
 119         do {
 120                 if (paddr > dmat->lowaddr
 121                  && paddr <= dmat->highaddr
 122                  && (dmat->filter == NULL
 123                   || (*dmat->filter)(dmat->filterarg, paddr) != 0))
 124                         retval = 1;
 125
 126                 dmat = dmat->parent;
 127         } while (retval == 0 && dmat != NULL);
 128         return (retval);
 129 }
 130
 131 #define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
 132 /*
 133  * Allocate a device specific dma_tag.
 134  */
 135 int
 136 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 137                    bus_size_t boundary, bus_addr_t lowaddr,
 138                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 139                    void *filterarg, bus_size_t maxsize, int nsegments,
 140                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 141 {
 142         bus_dma_tag_t newtag;
 143         int error = 0;
 144
 145         /* Return a NULL tag on failure */
 146         *dmat = NULL;
 147
 148         newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
 149
 150         newtag->parent = parent;
 151         newtag->alignment = alignment;
 152         newtag->boundary = boundary;
 153         newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 154         newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
 155         newtag->filter = filter;
 156         newtag->filterarg = filterarg;
 157         newtag->maxsize = maxsize;
 158         newtag->nsegments = nsegments;
 159         newtag->maxsegsz = maxsegsz;
 160         newtag->flags = flags;
 161         newtag->ref_count = 1; /* Count ourself */
 162         newtag->map_count = 0;
 163         newtag->segments = NULL;
 164
 165         /* Take into account any restrictions imposed by our parent tag */
 166         if (parent != NULL) {
 167                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 168                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 169                 /*
 170                  * XXX Not really correct??? Probably need to honor boundary
 171                  *     all the way up the inheritence chain.
 172                  */
 173                 newtag->boundary = MAX(parent->boundary, newtag->boundary);
 174                 if (newtag->filter == NULL) {
 175                         /*
 176                          * Short circuit looking at our parent directly
 177                          * since we have encapsulated all of its information
 178                          */
 179                         newtag->filter = parent->filter;
 180                         newtag->filterarg = parent->filterarg;
 181                         newtag->parent = parent->parent;
 182                 }
 183                 if (newtag->parent != NULL) {
 184                         parent->ref_count++;
 185                 }
 186         }
 187
 188         if (newtag->lowaddr < ptoa(Maxmem) &&
 189             (flags & BUS_DMA_ALLOCNOW) != 0) {
 190                 /* Must bounce */
 191
 192                 if (lowaddr > bounce_lowaddr) {
 193                         /*
 194                          * Go through the pool and kill any pages
 195                          * that don't reside below lowaddr.
 196                          */
 197                         panic("bus_dma_tag_create: page reallocation "
 198                               "not implemented");
 199                 }
 200                 if (ptoa(total_bpages) < maxsize) {
 201                         int pages;
 202
 203                         pages = atop(maxsize) - total_bpages;
 204
 205                         /* Add pages to our bounce pool */
 206                         if (alloc_bounce_pages(newtag, pages) < pages)
 207                                 error = ENOMEM;
 208                 }
 209                 /* Performed initial allocation */
 210                 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 211         }
 212
 213         if (error != 0) {
 214                 kfree(newtag, M_DEVBUF);
 215         } else {
 216                 *dmat = newtag;
 217         }
 218         return (error);
 219 }
 220
 221 int
 222 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 223 {
 224         if (dmat != NULL) {
 225
 226                 if (dmat->map_count != 0)
 227                         return (EBUSY);
 228
 229                 while (dmat != NULL) {
 230                         bus_dma_tag_t parent;
 231
 232                         parent = dmat->parent;
 233                         dmat->ref_count--;
 234                         if (dmat->ref_count == 0) {
 235                                 if (dmat->segments != NULL)
 236                                         kfree(dmat->segments, M_DEVBUF);
 237                                 kfree(dmat, M_DEVBUF);
 238                                 /*
 239                                  * Last reference count, so
 240                                  * release our reference
 241                                  * count on our parent.
 242                                  */
 243                                 dmat = parent;
 244                         } else
 245                                 dmat = NULL;
 246                 }
 247         }
 248         return (0);
 249 }
 250
 251 /*
 252  * Allocate a handle for mapping from kva/uva/physical
 253  * address space into bus device space.
 254  */
 255 int
 256 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 257 {
 258         int error;
 259
 260         error = 0;
 261
 262         if (dmat->segments == NULL) {
 263                 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
 264                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 265                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 266         }
 267
 268         if (dmat->lowaddr < ptoa(Maxmem)) {
 269                 /* Must bounce */
 270                 int maxpages;
 271
 272                 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
 273
 274                 /* Initialize the new map */
 275                 STAILQ_INIT(&((*mapp)->bpages));
 276                 /*
 277                  * Attempt to add pages to our pool on a per-instance
 278                  * basis up to a sane limit.
 279                  */
 280                 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
 281                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
 282                  || (dmat->map_count > 0
 283                   && total_bpages < maxpages)) {
 284                         int pages;
 285
 286                         if (dmat->lowaddr > bounce_lowaddr) {
 287                                 /*
 288                                  * Go through the pool and kill any pages
 289                                  * that don't reside below lowaddr.
 290                                  */
 291                                 panic("bus_dmamap_create: page reallocation "
 292                                       "not implemented");
 293                         }
 294
 295                         pages = MAX(atop(dmat->maxsize), 1);
 296                         pages = MIN(maxpages - total_bpages, pages);
 297                         pages = MAX(pages, 1);
 298                         if (alloc_bounce_pages(dmat, pages) < pages)
 299                                 error = ENOMEM;
 300
 301                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 302                                 if (error == 0)
 303                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 304                         } else {
 305                                 error = 0;
 306                         }
 307                 }
 308         } else {
 309                 *mapp = NULL;
 310         }
 311         if (error == 0)
 312                 dmat->map_count++;
 313         return (error);
 314 }
 315
 316 /*
 317  * Destroy a handle for mapping from kva/uva/physical
 318  * address space into bus device space.
 319  */
 320 int
 321 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 322 {
 323         if (map != NULL) {
 324                 if (STAILQ_FIRST(&map->bpages) != NULL)
 325                         return (EBUSY);
 326                 kfree(map, M_DEVBUF);
 327         }
 328         dmat->map_count--;
 329         return (0);
 330 }
 331
 332
 333 /*
 334  * Allocate a piece of memory that can be efficiently mapped into
 335  * bus device space based on the constraints lited in the dma tag.
 336  *
 337  * mapp is degenerate.  By definition this allocation should not require
 338  * bounce buffers so do not allocate a dma map.
 339  */
 340 int
 341 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 342                  bus_dmamap_t *mapp)
 343 {
 344         int mflags;
 345         /* If we succeed, no mapping/bouncing will be required */
 346         *mapp = NULL;
 347
 348         if (dmat->segments == NULL) {
 349                 KKASSERT(dmat->nsegments < 16384);
 350                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 351                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 352         }
 353
 354         if (flags & BUS_DMA_NOWAIT)
 355                 mflags = M_NOWAIT;
 356         else
 357                 mflags = M_WAITOK;
 358         if (flags & BUS_DMA_ZERO)
 359                 mflags |= M_ZERO;
 360
 361         if ((dmat->maxsize <= PAGE_SIZE) &&
 362             dmat->lowaddr >= ptoa(Maxmem)) {
 363                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 364                 /*
 365                  * XXX Check whether the allocation crossed a page boundary
 366                  * and retry with power-of-2 alignment in that case.
 367                  */
 368                 if ((((intptr_t)*vaddr) & PAGE_MASK) !=
 369                     (((intptr_t)*vaddr + dmat->maxsize) & PAGE_MASK)) {
 370                         size_t size;
 371                         kfree(*vaddr, M_DEVBUF);
 372                         /* XXX check for overflow? */
 373                         for (size = 1; size <= dmat->maxsize; size <<= 1)
 374                                 ;
 375                         *vaddr = kmalloc(size, M_DEVBUF, mflags);
 376                 }
 377         } else {
 378                 /*
 379                  * XXX Use Contigmalloc until it is merged into this facility
 380                  *     and handles multi-seg allocations.  Nobody is doing
 381                  *     multi-seg allocations yet though.
 382                  */
 383                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 384                     0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
 385                     dmat->boundary);
 386         }
 387         if (*vaddr == NULL)
 388                 return (ENOMEM);
 389         return (0);
 390 }
 391
 392 /*
 393  * Free a piece of memory and it's allociated dmamap, that was allocated
 394  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 395  */
 396 void
 397 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 398 {
 399         /*
 400          * dmamem does not need to be bounced, so the map should be
 401          * NULL
 402          */
 403         if (map != NULL)
 404                 panic("bus_dmamem_free: Invalid map freed\n");
 405         if ((dmat->maxsize <= PAGE_SIZE) &&
 406             dmat->lowaddr >= ptoa(Maxmem))
 407                 kfree(vaddr, M_DEVBUF);
 408         else
 409                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 410 }
 411
 412 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
 413
 414 /*
 415  * Map the buffer buf into bus space using the dmamap map.
 416  */
 417 int
 418 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 419                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 420                 void *callback_arg, int flags)
 421 {
 422         vm_offset_t             vaddr;
 423         vm_paddr_t              paddr;
 424         bus_dma_segment_t      *sg;
 425         int                     seg;
 426         int                     error;
 427         vm_paddr_t              nextpaddr;
 428         bus_addr_t              bmask;
 429
 430         if (map == NULL)
 431                 map = &nobounce_dmamap;
 432
 433         error = 0;
 434         /*
 435          * If we are being called during a callback, pagesneeded will
 436          * be non-zero, so we can avoid doing the work twice.
 437          */
 438         if (dmat->lowaddr < ptoa(Maxmem) &&
 439             map->pagesneeded == 0) {
 440                 vm_offset_t     vendaddr;
 441
 442                 /*
 443                  * Count the number of bounce pages
 444                  * needed in order to complete this transfer
 445                  */
 446                 vaddr = trunc_page((vm_offset_t)buf);
 447                 vendaddr = (vm_offset_t)buf + buflen;
 448
 449                 while (vaddr < vendaddr) {
 450                         paddr = pmap_kextract(vaddr);
 451                         if (run_filter(dmat, paddr) != 0) {
 452
 453                                 map->pagesneeded++;
 454                         }
 455                         vaddr += PAGE_SIZE;
 456                 }
 457         }
 458
 459         /* Reserve Necessary Bounce Pages */
 460         if (map->pagesneeded != 0) {
 461                 crit_enter();
 462                 if (reserve_bounce_pages(dmat, map) != 0) {
 463
 464                         /* Queue us for resources */
 465                         map->dmat = dmat;
 466                         map->buf = buf;
 467                         map->buflen = buflen;
 468                         map->callback = callback;
 469                         map->callback_arg = callback_arg;
 470
 471                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 472                         crit_exit();
 473
 474                         return (EINPROGRESS);
 475                 }
 476                 crit_exit();
 477         }
 478
 479         vaddr = (vm_offset_t)buf;
 480         sg = dmat->segments;
 481         seg = 1;
 482         sg->ds_len = 0;
 483         nextpaddr = 0;
 484         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 485
 486         /* force at least one segment */
 487         do {
 488                 bus_size_t      size;
 489
 490                 /*
 491                  * Per-page main loop
 492                  */
 493                 paddr = pmap_kextract(vaddr);
 494                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 495                 if (size > buflen)
 496                         size = buflen;
 497                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 498                         /*
 499                          * note: this paddr has the same in-page offset
 500                          * as vaddr and thus the paddr above, so the
 501                          * size does not have to be recalculated
 502                          */
 503                         paddr = add_bounce_page(dmat, map, vaddr, size);
 504                 }
 505
 506                 /*
 507                  * Fill in the bus_dma_segment
 508                  */
 509                 if (sg->ds_len == 0) {
 510                         sg->ds_addr = paddr;
 511                         sg->ds_len = size;
 512                 } else if (paddr == nextpaddr) {
 513                         sg->ds_len += size;
 514                 } else {
 515                         sg++;
 516                         seg++;
 517                         if (seg > dmat->nsegments)
 518                                 break;
 519                         sg->ds_addr = paddr;
 520                         sg->ds_len = size;
 521                 }
 522                 nextpaddr = paddr + size;
 523
 524                 /*
 525                  * Handle maxsegsz and boundary issues with a nested loop
 526                  */
 527                 for (;;) {
 528                         bus_size_t      tmpsize;
 529
 530                         /*
 531                          * Limit to the boundary and maximum segment size
 532                          */
 533                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 534                                 tmpsize = dmat->boundary -
 535                                           (sg->ds_addr & ~bmask);
 536                                 if (tmpsize > dmat->maxsegsz)
 537                                         tmpsize = dmat->maxsegsz;
 538                                 KKASSERT(tmpsize < sg->ds_len);
 539                         } else if (sg->ds_len > dmat->maxsegsz) {
 540                                 tmpsize = dmat->maxsegsz;
 541                         } else {
 542                                 break;
 543                         }
 544
 545                         /*
 546                          * Futz, split the data into a new segment.
 547                          */
 548                         if (seg >= dmat->nsegments)
 549                                 goto fail;
 550                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 551                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 552                         sg[0].ds_len = tmpsize;
 553                         sg++;
 554                         seg++;
 555                 }
 556
 557                 /*
 558                  * Adjust for loop
 559                  */
 560                 buflen -= size;
 561                 vaddr += size;
 562         } while (buflen > 0);
 563
 564 fail:
 565         if (buflen != 0) {
 566                 kprintf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
 567                        (u_long)buflen);
 568                 error = EFBIG;
 569         }
 570
 571         (*callback)(callback_arg, dmat->segments, seg, error);
 572
 573         return (0);
 574 }
 575
 576 /*
 577  * Utility function to load a linear buffer.  lastaddrp holds state
 578  * between invocations (for multiple-buffer loads).  segp contains
 579  * the starting segment on entrace, and the ending segment on exit.
 580  * first indicates if this is the first invocation of this function.
 581  */
 582 static int
 583 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 584                         void *buf, bus_size_t buflen,
 585                         struct thread *td,
 586                         int flags,
 587                         vm_offset_t *lastaddrp,
 588                         int *segp,
 589                         int first)
 590 {
 591         bus_dma_segment_t *segs;
 592         bus_size_t sgsize;
 593         bus_addr_t curaddr, lastaddr, baddr, bmask;
 594         vm_offset_t vaddr = (vm_offset_t)buf;
 595         int seg;
 596         pmap_t pmap;
 597
 598         if (td->td_proc != NULL)
 599                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 600         else
 601                 pmap = NULL;
 602
 603         segs = dmat->segments;
 604         lastaddr = *lastaddrp;
 605         bmask  = ~(dmat->boundary - 1);
 606
 607         for (seg = *segp; buflen > 0 ; ) {
 608                 /*
 609                  * Get the physical address for this segment.
 610                  */
 611                 if (pmap)
 612                         curaddr = pmap_extract(pmap, vaddr);
 613                 else
 614                         curaddr = pmap_kextract(vaddr);
 615
 616                 /*
 617                  * Compute the segment size, and adjust counts.
 618                  */
 619                 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
 620                 if (buflen < sgsize)
 621                         sgsize = buflen;
 622
 623                 /*
 624                  * Make sure we don't cross any boundaries.
 625                  */
 626                 if (dmat->boundary > 0) {
 627                         baddr = (curaddr + dmat->boundary) & bmask;
 628                         if (sgsize > (baddr - curaddr))
 629                                 sgsize = (baddr - curaddr);
 630                 }
 631
 632                 /*
 633                  * Insert chunk into a segment, coalescing with
 634                  * previous segment if possible.
 635                  */
 636                 if (first) {
 637                         segs[seg].ds_addr = curaddr;
 638                         segs[seg].ds_len = sgsize;
 639                         first = 0;
 640                 } else {
 641                         if (curaddr == lastaddr &&
 642                             (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
 643                             (dmat->boundary == 0 ||
 644                              (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 645                                 segs[seg].ds_len += sgsize;
 646                         else {
 647                                 if (++seg >= dmat->nsegments)
 648                                         break;
 649                                 segs[seg].ds_addr = curaddr;
 650                                 segs[seg].ds_len = sgsize;
 651                         }
 652                 }
 653
 654                 lastaddr = curaddr + sgsize;
 655                 vaddr += sgsize;
 656                 buflen -= sgsize;
 657         }
 658
 659         *segp = seg;
 660         *lastaddrp = lastaddr;
 661
 662         /*
 663          * Did we fit?
 664          */
 665         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 666 }
 667
 668 /*
 669  * Like _bus_dmamap_load(), but for mbufs.
 670  */
 671 int
 672 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 673                      struct mbuf *m0,
 674                      bus_dmamap_callback2_t *callback, void *callback_arg,
 675                      int flags)
 676 {
 677         int nsegs, error;
 678
 679         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 680                 ("bus_dmamap_load_mbuf: No support for bounce pages!"));
 681         KASSERT(m0->m_flags & M_PKTHDR,
 682                 ("bus_dmamap_load_mbuf: no packet header"));
 683
 684         nsegs = 0;
 685         error = 0;
 686         if (m0->m_pkthdr.len <= dmat->maxsize) {
 687                 int first = 1;
 688                 vm_offset_t lastaddr = 0;
 689                 struct mbuf *m;
 690
 691                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 692                         if ( m->m_len == 0 )
 693                                 continue;
 694                         error = _bus_dmamap_load_buffer(dmat,
 695                                         m->m_data, m->m_len,
 696                                         curthread, flags, &lastaddr,
 697                                         &nsegs, first);
 698                         first = 0;
 699                 }
 700         } else {
 701                 error = EINVAL;
 702         }
 703
 704         if (error) {
 705                 /* force "no valid mappings" in callback */
 706                 (*callback)(callback_arg, dmat->segments, 0, 0, error);
 707         } else {
 708                 (*callback)(callback_arg, dmat->segments,
 709                             nsegs+1, m0->m_pkthdr.len, error);
 710         }
 711         return (error);
 712 }
 713
 714 /*
 715  * Like _bus_dmamap_load(), but for uios.
 716  */
 717 int
 718 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 719                     struct uio *uio,
 720                     bus_dmamap_callback2_t *callback, void *callback_arg,
 721                     int flags)
 722 {
 723         vm_offset_t lastaddr;
 724         int nsegs, error, first, i;
 725         bus_size_t resid;
 726         struct iovec *iov;
 727         struct thread *td = NULL;
 728
 729         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 730                 ("bus_dmamap_load_uio: No support for bounce pages!"));
 731
 732         resid = uio->uio_resid;
 733         iov = uio->uio_iov;
 734
 735         if (uio->uio_segflg == UIO_USERSPACE) {
 736                 td = uio->uio_td;
 737                 KASSERT(td != NULL && td->td_proc != NULL,
 738                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 739         }
 740
 741         nsegs = 0;
 742         error = 0;
 743         first = 1;
 744         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 745                 /*
 746                  * Now at the first iovec to load.  Load each iovec
 747                  * until we have exhausted the residual count.
 748                  */
 749                 bus_size_t minlen =
 750                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 751                 caddr_t addr = (caddr_t) iov[i].iov_base;
 752
 753                 error = _bus_dmamap_load_buffer(dmat,
 754                                 addr, minlen,
 755                                 td, flags, &lastaddr, &nsegs, first);
 756                 first = 0;
 757
 758                 resid -= minlen;
 759         }
 760
 761         if (error) {
 762                 /* force "no valid mappings" in callback */
 763                 (*callback)(callback_arg, dmat->segments, 0, 0, error);
 764         } else {
 765                 (*callback)(callback_arg, dmat->segments,
 766                             nsegs+1, uio->uio_resid, error);
 767         }
 768         return (error);
 769 }
 770
 771 /*
 772  * Release the mapping held by map.
 773  */
 774 void
 775 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 776 {
 777         struct bounce_page *bpage;
 778
 779         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 780                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 781                 free_bounce_page(dmat, bpage);
 782         }
 783 }
 784
 785 void
 786 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 787 {
 788         struct bounce_page *bpage;
 789
 790         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 791
 792                 /*
 793                  * Handle data bouncing.  We might also
 794                  * want to add support for invalidating
 795                  * the caches on broken hardware
 796                  */
 797                 switch (op) {
 798                 case BUS_DMASYNC_PREWRITE:
 799                         while (bpage != NULL) {
 800                                 bcopy((void *)bpage->datavaddr,
 801                                       (void *)bpage->vaddr,
 802                                       bpage->datacount);
 803                                 bpage = STAILQ_NEXT(bpage, links);
 804                         }
 805                         break;
 806
 807                 case BUS_DMASYNC_POSTREAD:
 808                         while (bpage != NULL) {
 809                                 bcopy((void *)bpage->vaddr,
 810                                       (void *)bpage->datavaddr,
 811                                       bpage->datacount);
 812                                 bpage = STAILQ_NEXT(bpage, links);
 813                         }
 814                         break;
 815                 case BUS_DMASYNC_PREREAD:
 816                 case BUS_DMASYNC_POSTWRITE:
 817                         /* No-ops */
 818                         break;
 819                 }
 820         }
 821 }
 822
 823 static int
 824 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 825 {
 826         int count;
 827
 828         count = 0;
 829         if (total_bpages == 0) {
 830                 STAILQ_INIT(&bounce_page_list);
 831                 STAILQ_INIT(&bounce_map_waitinglist);
 832                 STAILQ_INIT(&bounce_map_callbacklist);
 833         }
 834
 835         while (numpages > 0) {
 836                 struct bounce_page *bpage;
 837
 838                 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
 839
 840                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 841                                                          M_NOWAIT, 0ul,
 842                                                          dmat->lowaddr,
 843                                                          PAGE_SIZE,
 844                                                          0);
 845                 if (bpage->vaddr == 0) {
 846                         kfree(bpage, M_DEVBUF);
 847                         break;
 848                 }
 849                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 850                 crit_enter();
 851                 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
 852                 total_bpages++;
 853                 free_bpages++;
 854                 crit_exit();
 855                 count++;
 856                 numpages--;
 857         }
 858         return (count);
 859 }
 860
 861 static int
 862 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
 863 {
 864         int pages;
 865
 866         pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
 867         free_bpages -= pages;
 868         reserved_bpages += pages;
 869         map->pagesreserved += pages;
 870         pages = map->pagesneeded - map->pagesreserved;
 871
 872         return (pages);
 873 }
 874
 875 static bus_addr_t
 876 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 877                 bus_size_t size)
 878 {
 879         struct bounce_page *bpage;
 880
 881         if (map->pagesneeded == 0)
 882                 panic("add_bounce_page: map doesn't need any pages");
 883         map->pagesneeded--;
 884
 885         if (map->pagesreserved == 0)
 886                 panic("add_bounce_page: map doesn't need any pages");
 887         map->pagesreserved--;
 888
 889         crit_enter();
 890         bpage = STAILQ_FIRST(&bounce_page_list);
 891         if (bpage == NULL)
 892                 panic("add_bounce_page: free page list is empty");
 893
 894         STAILQ_REMOVE_HEAD(&bounce_page_list, links);
 895         reserved_bpages--;
 896         active_bpages++;
 897         crit_exit();
 898
 899         bpage->datavaddr = vaddr;
 900         bpage->datacount = size;
 901         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
 902         return (bpage->busaddr);
 903 }
 904
 905 static void
 906 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 907 {
 908         struct bus_dmamap *map;
 909
 910         bpage->datavaddr = 0;
 911         bpage->datacount = 0;
 912
 913         crit_enter();
 914         STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
 915         free_bpages++;
 916         active_bpages--;
 917         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
 918                 if (reserve_bounce_pages(map->dmat, map) == 0) {
 919                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
 920                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
 921                                            map, links);
 922                         busdma_swi_pending = 1;
 923                         setsoftvm();
 924                 }
 925         }
 926         crit_exit();
 927 }
 928
 929 void
 930 busdma_swi(void)
 931 {
 932         struct bus_dmamap *map;
 933
 934         crit_enter();
 935         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
 936                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
 937                 crit_exit();
 938                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
 939                                 map->callback, map->callback_arg, /*flags*/0);
 940                 crit_enter();
 941         }
 942         crit_exit();
 943 }