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                 if (*mapp == NULL)
 274                         return (ENOMEM);
 275                 /* Initialize the new map */
 276                 STAILQ_INIT(&((*mapp)->bpages));
 277                 /*
 278                  * Attempt to add pages to our pool on a per-instance
 279                  * basis up to a sane limit.
 280                  */
 281                 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
 282                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
 283                  || (dmat->map_count > 0
 284                   && total_bpages < maxpages)) {
 285                         int pages;
 286
 287                         if (dmat->lowaddr > bounce_lowaddr) {
 288                                 /*
 289                                  * Go through the pool and kill any pages
 290                                  * that don't reside below lowaddr.
 291                                  */
 292                                 panic("bus_dmamap_create: page reallocation "
 293                                       "not implemented");
 294                         }
 295
 296                         pages = MAX(atop(dmat->maxsize), 1);
 297                         pages = MIN(maxpages - total_bpages, pages);
 298                         pages = MAX(pages, 1);
 299                         if (alloc_bounce_pages(dmat, pages) < pages)
 300                                 error = ENOMEM;
 301
 302                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 303                                 if (error == 0)
 304                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 305                         } else {
 306                                 error = 0;
 307                         }
 308                 }
 309         } else {
 310                 *mapp = NULL;
 311         }
 312         if (error == 0)
 313                 dmat->map_count++;
 314         return (error);
 315 }
 316
 317 /*
 318  * Destroy a handle for mapping from kva/uva/physical
 319  * address space into bus device space.
 320  */
 321 int
 322 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 323 {
 324         if (map != NULL) {
 325                 if (STAILQ_FIRST(&map->bpages) != NULL)
 326                         return (EBUSY);
 327                 kfree(map, M_DEVBUF);
 328         }
 329         dmat->map_count--;
 330         return (0);
 331 }
 332
 333
 334 /*
 335  * Allocate a piece of memory that can be efficiently mapped into
 336  * bus device space based on the constraints lited in the dma tag.
 337  *
 338  * mapp is degenerate.  By definition this allocation should not require
 339  * bounce buffers so do not allocate a dma map.
 340  */
 341 int
 342 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 343                  bus_dmamap_t *mapp)
 344 {
 345         int mflags;
 346         /* If we succeed, no mapping/bouncing will be required */
 347         *mapp = NULL;
 348
 349         if (dmat->segments == NULL) {
 350                 KKASSERT(dmat->nsegments < 16384);
 351                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 352                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 353         }
 354
 355         if (flags & BUS_DMA_NOWAIT)
 356                 mflags = M_NOWAIT;
 357         else
 358                 mflags = M_WAITOK;
 359         if (flags & BUS_DMA_ZERO)
 360                 mflags |= M_ZERO;
 361
 362         if ((dmat->maxsize <= PAGE_SIZE) &&
 363             dmat->lowaddr >= ptoa(Maxmem)) {
 364                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 365                 /*
 366                  * XXX Check whether the allocation crossed a page boundary
 367                  * and retry with power-of-2 alignment in that case.
 368                  */
 369                 if ((((intptr_t)*vaddr) & PAGE_MASK) !=
 370                     (((intptr_t)*vaddr + dmat->maxsize) & PAGE_MASK)) {
 371                         size_t size;
 372                         kfree(*vaddr, M_DEVBUF);
 373                         /* XXX check for overflow? */
 374                         for (size = 1; size <= dmat->maxsize; size <<= 1)
 375                                 ;
 376                         *vaddr = kmalloc(size, M_DEVBUF, mflags);
 377                 }
 378         } else {
 379                 /*
 380                  * XXX Use Contigmalloc until it is merged into this facility
 381                  *     and handles multi-seg allocations.  Nobody is doing
 382                  *     multi-seg allocations yet though.
 383                  */
 384                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 385                     0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
 386                     dmat->boundary);
 387         }
 388         if (*vaddr == NULL)
 389                 return (ENOMEM);
 390         return (0);
 391 }
 392
 393 /*
 394  * Free a piece of memory and it's allociated dmamap, that was allocated
 395  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 396  */
 397 void
 398 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 399 {
 400         /*
 401          * dmamem does not need to be bounced, so the map should be
 402          * NULL
 403          */
 404         if (map != NULL)
 405                 panic("bus_dmamem_free: Invalid map freed\n");
 406         if ((dmat->maxsize <= PAGE_SIZE) &&
 407             dmat->lowaddr >= ptoa(Maxmem))
 408                 kfree(vaddr, M_DEVBUF);
 409         else
 410                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 411 }
 412
 413 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
 414
 415 /*
 416  * Map the buffer buf into bus space using the dmamap map.
 417  */
 418 int
 419 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 420                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 421                 void *callback_arg, int flags)
 422 {
 423         vm_offset_t             vaddr;
 424         vm_paddr_t              paddr;
 425         bus_dma_segment_t      *sg;
 426         int                     seg;
 427         int                     error;
 428         vm_paddr_t              nextpaddr;
 429         bus_addr_t              bmask;
 430
 431         if (map == NULL)
 432                 map = &nobounce_dmamap;
 433
 434         error = 0;
 435         /*
 436          * If we are being called during a callback, pagesneeded will
 437          * be non-zero, so we can avoid doing the work twice.
 438          */
 439         if (dmat->lowaddr < ptoa(Maxmem) &&
 440             map->pagesneeded == 0) {
 441                 vm_offset_t     vendaddr;
 442
 443                 /*
 444                  * Count the number of bounce pages
 445                  * needed in order to complete this transfer
 446                  */
 447                 vaddr = trunc_page((vm_offset_t)buf);
 448                 vendaddr = (vm_offset_t)buf + buflen;
 449
 450                 while (vaddr < vendaddr) {
 451                         paddr = pmap_kextract(vaddr);
 452                         if (run_filter(dmat, paddr) != 0) {
 453
 454                                 map->pagesneeded++;
 455                         }
 456                         vaddr += PAGE_SIZE;
 457                 }
 458         }
 459
 460         /* Reserve Necessary Bounce Pages */
 461         if (map->pagesneeded != 0) {
 462                 crit_enter();
 463                 if (reserve_bounce_pages(dmat, map) != 0) {
 464
 465                         /* Queue us for resources */
 466                         map->dmat = dmat;
 467                         map->buf = buf;
 468                         map->buflen = buflen;
 469                         map->callback = callback;
 470                         map->callback_arg = callback_arg;
 471
 472                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 473                         crit_exit();
 474
 475                         return (EINPROGRESS);
 476                 }
 477                 crit_exit();
 478         }
 479
 480         vaddr = (vm_offset_t)buf;
 481         sg = dmat->segments;
 482         seg = 1;
 483         sg->ds_len = 0;
 484         nextpaddr = 0;
 485         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 486
 487         /* force at least one segment */
 488         do {
 489                 bus_size_t      size;
 490
 491                 /*
 492                  * Per-page main loop
 493                  */
 494                 paddr = pmap_kextract(vaddr);
 495                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 496                 if (size > buflen)
 497                         size = buflen;
 498                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 499                         /*
 500                          * note: this paddr has the same in-page offset
 501                          * as vaddr and thus the paddr above, so the
 502                          * size does not have to be recalculated
 503                          */
 504                         paddr = add_bounce_page(dmat, map, vaddr, size);
 505                 }
 506
 507                 /*
 508                  * Fill in the bus_dma_segment
 509                  */
 510                 if (sg->ds_len == 0) {
 511                         sg->ds_addr = paddr;
 512                         sg->ds_len = size;
 513                 } else if (paddr == nextpaddr) {
 514                         sg->ds_len += size;
 515                 } else {
 516                         sg++;
 517                         seg++;
 518                         if (seg > dmat->nsegments)
 519                                 break;
 520                         sg->ds_addr = paddr;
 521                         sg->ds_len = size;
 522                 }
 523                 nextpaddr = paddr + size;
 524
 525                 /*
 526                  * Handle maxsegsz and boundary issues with a nested loop
 527                  */
 528                 for (;;) {
 529                         bus_size_t      tmpsize;
 530
 531                         /*
 532                          * Limit to the boundary and maximum segment size
 533                          */
 534                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 535                                 tmpsize = dmat->boundary -
 536                                           (sg->ds_addr & ~bmask);
 537                                 if (tmpsize > dmat->maxsegsz)
 538                                         tmpsize = dmat->maxsegsz;
 539                                 KKASSERT(tmpsize < sg->ds_len);
 540                         } else if (sg->ds_len > dmat->maxsegsz) {
 541                                 tmpsize = dmat->maxsegsz;
 542                         } else {
 543                                 break;
 544                         }
 545
 546                         /*
 547                          * Futz, split the data into a new segment.
 548                          */
 549                         if (seg >= dmat->nsegments)
 550                                 goto fail;
 551                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 552                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 553                         sg[0].ds_len = tmpsize;
 554                         sg++;
 555                         seg++;
 556                 }
 557
 558                 /*
 559                  * Adjust for loop
 560                  */
 561                 buflen -= size;
 562                 vaddr += size;
 563         } while (buflen > 0);
 564
 565 fail:
 566         if (buflen != 0) {
 567                 kprintf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
 568                        (u_long)buflen);
 569                 error = EFBIG;
 570         }
 571
 572         (*callback)(callback_arg, dmat->segments, seg, error);
 573
 574         return (0);
 575 }
 576
 577 /*
 578  * Utility function to load a linear buffer.  lastaddrp holds state
 579  * between invocations (for multiple-buffer loads).  segp contains
 580  * the starting segment on entrace, and the ending segment on exit.
 581  * first indicates if this is the first invocation of this function.
 582  */
 583 static int
 584 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 585                         void *buf, bus_size_t buflen,
 586                         struct thread *td,
 587                         int flags,
 588                         vm_offset_t *lastaddrp,
 589                         int *segp,
 590                         int first)
 591 {
 592         bus_dma_segment_t *segs;
 593         bus_size_t sgsize;
 594         bus_addr_t curaddr, lastaddr, baddr, bmask;
 595         vm_offset_t vaddr = (vm_offset_t)buf;
 596         int seg;
 597         pmap_t pmap;
 598
 599         if (td->td_proc != NULL)
 600                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 601         else
 602                 pmap = NULL;
 603
 604         segs = dmat->segments;
 605         lastaddr = *lastaddrp;
 606         bmask  = ~(dmat->boundary - 1);
 607
 608         for (seg = *segp; buflen > 0 ; ) {
 609                 /*
 610                  * Get the physical address for this segment.
 611                  */
 612                 if (pmap)
 613                         curaddr = pmap_extract(pmap, vaddr);
 614                 else
 615                         curaddr = pmap_kextract(vaddr);
 616
 617                 /*
 618                  * Compute the segment size, and adjust counts.
 619                  */
 620                 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
 621                 if (buflen < sgsize)
 622                         sgsize = buflen;
 623
 624                 /*
 625                  * Make sure we don't cross any boundaries.
 626                  */
 627                 if (dmat->boundary > 0) {
 628                         baddr = (curaddr + dmat->boundary) & bmask;
 629                         if (sgsize > (baddr - curaddr))
 630                                 sgsize = (baddr - curaddr);
 631                 }
 632
 633                 /*
 634                  * Insert chunk into a segment, coalescing with
 635                  * previous segment if possible.
 636                  */
 637                 if (first) {
 638                         segs[seg].ds_addr = curaddr;
 639                         segs[seg].ds_len = sgsize;
 640                         first = 0;
 641                 } else {
 642                         if (curaddr == lastaddr &&
 643                             (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
 644                             (dmat->boundary == 0 ||
 645                              (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 646                                 segs[seg].ds_len += sgsize;
 647                         else {
 648                                 if (++seg >= dmat->nsegments)
 649                                         break;
 650                                 segs[seg].ds_addr = curaddr;
 651                                 segs[seg].ds_len = sgsize;
 652                         }
 653                 }
 654
 655                 lastaddr = curaddr + sgsize;
 656                 vaddr += sgsize;
 657                 buflen -= sgsize;
 658         }
 659
 660         *segp = seg;
 661         *lastaddrp = lastaddr;
 662
 663         /*
 664          * Did we fit?
 665          */
 666         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 667 }
 668
 669 /*
 670  * Like _bus_dmamap_load(), but for mbufs.
 671  */
 672 int
 673 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 674                      struct mbuf *m0,
 675                      bus_dmamap_callback2_t *callback, void *callback_arg,
 676                      int flags)
 677 {
 678         int nsegs, error;
 679
 680         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 681                 ("bus_dmamap_load_mbuf: No support for bounce pages!"));
 682         KASSERT(m0->m_flags & M_PKTHDR,
 683                 ("bus_dmamap_load_mbuf: no packet header"));
 684
 685         nsegs = 0;
 686         error = 0;
 687         if (m0->m_pkthdr.len <= dmat->maxsize) {
 688                 int first = 1;
 689                 vm_offset_t lastaddr = 0;
 690                 struct mbuf *m;
 691
 692                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 693                         if ( m->m_len == 0 )
 694                                 continue;
 695                         error = _bus_dmamap_load_buffer(dmat,
 696                                         m->m_data, m->m_len,
 697                                         curthread, flags, &lastaddr,
 698                                         &nsegs, first);
 699                         first = 0;
 700                 }
 701         } else {
 702                 error = EINVAL;
 703         }
 704
 705         if (error) {
 706                 /* force "no valid mappings" in callback */
 707                 (*callback)(callback_arg, dmat->segments, 0, 0, error);
 708         } else {
 709                 (*callback)(callback_arg, dmat->segments,
 710                             nsegs+1, m0->m_pkthdr.len, error);
 711         }
 712         return (error);
 713 }
 714
 715 /*
 716  * Like _bus_dmamap_load(), but for uios.
 717  */
 718 int
 719 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 720                     struct uio *uio,
 721                     bus_dmamap_callback2_t *callback, void *callback_arg,
 722                     int flags)
 723 {
 724         vm_offset_t lastaddr;
 725         int nsegs, error, first, i;
 726         bus_size_t resid;
 727         struct iovec *iov;
 728         struct thread *td = NULL;
 729
 730         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 731                 ("bus_dmamap_load_uio: No support for bounce pages!"));
 732
 733         resid = uio->uio_resid;
 734         iov = uio->uio_iov;
 735
 736         if (uio->uio_segflg == UIO_USERSPACE) {
 737                 td = uio->uio_td;
 738                 KASSERT(td != NULL && td->td_proc != NULL,
 739                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 740         }
 741
 742         nsegs = 0;
 743         error = 0;
 744         first = 1;
 745         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 746                 /*
 747                  * Now at the first iovec to load.  Load each iovec
 748                  * until we have exhausted the residual count.
 749                  */
 750                 bus_size_t minlen =
 751                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 752                 caddr_t addr = (caddr_t) iov[i].iov_base;
 753
 754                 error = _bus_dmamap_load_buffer(dmat,
 755                                 addr, minlen,
 756                                 td, flags, &lastaddr, &nsegs, first);
 757                 first = 0;
 758
 759                 resid -= minlen;
 760         }
 761
 762         if (error) {
 763                 /* force "no valid mappings" in callback */
 764                 (*callback)(callback_arg, dmat->segments, 0, 0, error);
 765         } else {
 766                 (*callback)(callback_arg, dmat->segments,
 767                             nsegs+1, uio->uio_resid, error);
 768         }
 769         return (error);
 770 }
 771
 772 /*
 773  * Release the mapping held by map.
 774  */
 775 void
 776 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 777 {
 778         struct bounce_page *bpage;
 779
 780         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 781                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 782                 free_bounce_page(dmat, bpage);
 783         }
 784 }
 785
 786 void
 787 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 788 {
 789         struct bounce_page *bpage;
 790
 791         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 792
 793                 /*
 794                  * Handle data bouncing.  We might also
 795                  * want to add support for invalidating
 796                  * the caches on broken hardware
 797                  */
 798                 switch (op) {
 799                 case BUS_DMASYNC_PREWRITE:
 800                         while (bpage != NULL) {
 801                                 bcopy((void *)bpage->datavaddr,
 802                                       (void *)bpage->vaddr,
 803                                       bpage->datacount);
 804                                 bpage = STAILQ_NEXT(bpage, links);
 805                         }
 806                         break;
 807
 808                 case BUS_DMASYNC_POSTREAD:
 809                         while (bpage != NULL) {
 810                                 bcopy((void *)bpage->vaddr,
 811                                       (void *)bpage->datavaddr,
 812                                       bpage->datacount);
 813                                 bpage = STAILQ_NEXT(bpage, links);
 814                         }
 815                         break;
 816                 case BUS_DMASYNC_PREREAD:
 817                 case BUS_DMASYNC_POSTWRITE:
 818                         /* No-ops */
 819                         break;
 820                 }
 821         }
 822 }
 823
 824 static int
 825 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 826 {
 827         int count;
 828
 829         count = 0;
 830         if (total_bpages == 0) {
 831                 STAILQ_INIT(&bounce_page_list);
 832                 STAILQ_INIT(&bounce_map_waitinglist);
 833                 STAILQ_INIT(&bounce_map_callbacklist);
 834         }
 835
 836         while (numpages > 0) {
 837                 struct bounce_page *bpage;
 838
 839                 bpage = (struct bounce_page *)kmalloc(sizeof(*bpage), M_DEVBUF,
 840                                                      M_INTWAIT | M_ZERO);
 841
 842                 if (bpage == NULL)
 843                         break;
 844                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 845                                                          M_NOWAIT, 0ul,
 846                                                          dmat->lowaddr,
 847                                                          PAGE_SIZE,
 848                                                          0);
 849                 if (bpage->vaddr == 0) {
 850                         kfree(bpage, M_DEVBUF);
 851                         break;
 852                 }
 853                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 854                 crit_enter();
 855                 STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
 856                 total_bpages++;
 857                 free_bpages++;
 858                 crit_exit();
 859                 count++;
 860                 numpages--;
 861         }
 862         return (count);
 863 }
 864
 865 static int
 866 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
 867 {
 868         int pages;
 869
 870         pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
 871         free_bpages -= pages;
 872         reserved_bpages += pages;
 873         map->pagesreserved += pages;
 874         pages = map->pagesneeded - map->pagesreserved;
 875
 876         return (pages);
 877 }
 878
 879 static bus_addr_t
 880 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 881                 bus_size_t size)
 882 {
 883         struct bounce_page *bpage;
 884
 885         if (map->pagesneeded == 0)
 886                 panic("add_bounce_page: map doesn't need any pages");
 887         map->pagesneeded--;
 888
 889         if (map->pagesreserved == 0)
 890                 panic("add_bounce_page: map doesn't need any pages");
 891         map->pagesreserved--;
 892
 893         crit_enter();
 894         bpage = STAILQ_FIRST(&bounce_page_list);
 895         if (bpage == NULL)
 896                 panic("add_bounce_page: free page list is empty");
 897
 898         STAILQ_REMOVE_HEAD(&bounce_page_list, links);
 899         reserved_bpages--;
 900         active_bpages++;
 901         crit_exit();
 902
 903         bpage->datavaddr = vaddr;
 904         bpage->datacount = size;
 905         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
 906         return (bpage->busaddr);
 907 }
 908
 909 static void
 910 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
 911 {
 912         struct bus_dmamap *map;
 913
 914         bpage->datavaddr = 0;
 915         bpage->datacount = 0;
 916
 917         crit_enter();
 918         STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
 919         free_bpages++;
 920         active_bpages--;
 921         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
 922                 if (reserve_bounce_pages(map->dmat, map) == 0) {
 923                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
 924                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
 925                                            map, links);
 926                         busdma_swi_pending = 1;
 927                         setsoftvm();
 928                 }
 929         }
 930         crit_exit();
 931 }
 932
 933 void
 934 busdma_swi(void)
 935 {
 936         struct bus_dmamap *map;
 937
 938         crit_enter();
 939         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
 940                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
 941                 crit_exit();
 942                 bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
 943                                 map->callback, map->callback_arg, /*flags*/0);
 944                 crit_enter();
 945         }
 946         crit_exit();
 947 }