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