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