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_COULD_BOUNCE    BUS_DMA_BUS3
  73 #define BUS_DMA_MIN_ALLOC_COMP  BUS_DMA_BUS4
  74
  75 struct bounce_page {
  76         vm_offset_t     vaddr;          /* kva of bounce buffer */
  77         bus_addr_t      busaddr;        /* Physical address */
  78         vm_offset_t     datavaddr;      /* kva of client data */
  79         bus_size_t      datacount;      /* client data count */
  80         STAILQ_ENTRY(bounce_page) links;
  81 };
  82
  83 int busdma_swi_pending;
  84
  85 static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  86 static int free_bpages;
  87 static int reserved_bpages;
  88 static int active_bpages;
  89 static int total_bpages;
  90 static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
  91
  92 struct bus_dmamap {
  93         struct bp_list  bpages;
  94         int             pagesneeded;
  95         int             pagesreserved;
  96         bus_dma_tag_t   dmat;
  97         void            *buf;           /* unmapped buffer pointer */
  98         bus_size_t      buflen;         /* unmapped buffer length */
  99         bus_dmamap_callback_t *callback;
 100         void            *callback_arg;
 101         STAILQ_ENTRY(bus_dmamap) links;
 102 };
 103
 104 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 105 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 106 static struct bus_dmamap nobounce_dmamap;
 107
 108 static int              alloc_bounce_pages(bus_dma_tag_t, u_int);
 109 static int              reserve_bounce_pages(bus_dma_tag_t, bus_dmamap_t);
 110 static bus_addr_t       add_bounce_page(bus_dma_tag_t, bus_dmamap_t,
 111                             vm_offset_t, bus_size_t);
 112 static void             free_bounce_page(bus_dma_tag_t, struct bounce_page *);
 113
 114 SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 115 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 116            "Total bounce pages");
 117
 118 static __inline int
 119 run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
 120 {
 121         int retval;
 122
 123         retval = 0;
 124         do {
 125                 if (paddr > dmat->lowaddr
 126                  && paddr <= dmat->highaddr
 127                  && (dmat->filter == NULL
 128                   || (*dmat->filter)(dmat->filterarg, paddr) != 0))
 129                         retval = 1;
 130
 131                 dmat = dmat->parent;
 132         } while (retval == 0 && dmat != NULL);
 133         return (retval);
 134 }
 135
 136 /*
 137  * Allocate a device specific dma_tag.
 138  */
 139 int
 140 bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 141                    bus_size_t boundary, bus_addr_t lowaddr,
 142                    bus_addr_t highaddr, bus_dma_filter_t *filter,
 143                    void *filterarg, bus_size_t maxsize, int nsegments,
 144                    bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
 145 {
 146         bus_dma_tag_t newtag;
 147         int error = 0;
 148
 149         /* Return a NULL tag on failure */
 150         *dmat = NULL;
 151
 152         newtag = kmalloc(sizeof(*newtag), M_DEVBUF, M_INTWAIT);
 153
 154         newtag->parent = parent;
 155         newtag->alignment = alignment;
 156         newtag->boundary = boundary;
 157         newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
 158         newtag->highaddr = trunc_page((vm_paddr_t)highaddr) + (PAGE_SIZE - 1);
 159         newtag->filter = filter;
 160         newtag->filterarg = filterarg;
 161         newtag->maxsize = maxsize;
 162         newtag->nsegments = nsegments;
 163         newtag->maxsegsz = maxsegsz;
 164         newtag->flags = flags;
 165         newtag->ref_count = 1; /* Count ourself */
 166         newtag->map_count = 0;
 167         newtag->segments = NULL;
 168
 169         /* Take into account any restrictions imposed by our parent tag */
 170         if (parent != NULL) {
 171                 newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
 172                 newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
 173
 174                 if (newtag->boundary == 0) {
 175                         newtag->boundary = parent->boundary;
 176                 } else if (parent->boundary != 0) {
 177                         newtag->boundary = MIN(parent->boundary,
 178                                                newtag->boundary);
 179                 }
 180
 181                 if (newtag->filter == NULL) {
 182                         /*
 183                          * Short circuit looking at our parent directly
 184                          * since we have encapsulated all of its information
 185                          */
 186                         newtag->filter = parent->filter;
 187                         newtag->filterarg = parent->filterarg;
 188                         newtag->parent = parent->parent;
 189                 }
 190                 if (newtag->parent != NULL)
 191                         parent->ref_count++;
 192         }
 193
 194         if (newtag->lowaddr < ptoa(Maxmem))
 195                 newtag->flags |= BUS_DMA_COULD_BOUNCE;
 196
 197         if ((newtag->flags & BUS_DMA_COULD_BOUNCE) &&
 198             (flags & BUS_DMA_ALLOCNOW) != 0) {
 199                 /* Must bounce */
 200
 201                 if (lowaddr > bounce_lowaddr) {
 202                         /*
 203                          * Go through the pool and kill any pages
 204                          * that don't reside below lowaddr.
 205                          */
 206                         panic("bus_dma_tag_create: page reallocation "
 207                               "not implemented");
 208                 }
 209                 if (ptoa(total_bpages) < maxsize) {
 210                         int pages;
 211
 212                         pages = atop(maxsize) - total_bpages;
 213
 214                         /* Add pages to our bounce pool */
 215                         if (alloc_bounce_pages(newtag, pages) < pages)
 216                                 error = ENOMEM;
 217                 }
 218                 /* Performed initial allocation */
 219                 newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
 220         }
 221
 222         if (error != 0) {
 223                 kfree(newtag, M_DEVBUF);
 224         } else {
 225                 *dmat = newtag;
 226         }
 227         return (error);
 228 }
 229
 230 int
 231 bus_dma_tag_destroy(bus_dma_tag_t dmat)
 232 {
 233         if (dmat != NULL) {
 234                 if (dmat->map_count != 0)
 235                         return (EBUSY);
 236
 237                 while (dmat != NULL) {
 238                         bus_dma_tag_t parent;
 239
 240                         parent = dmat->parent;
 241                         dmat->ref_count--;
 242                         if (dmat->ref_count == 0) {
 243                                 if (dmat->segments != NULL)
 244                                         kfree(dmat->segments, M_DEVBUF);
 245                                 kfree(dmat, M_DEVBUF);
 246                                 /*
 247                                  * Last reference count, so
 248                                  * release our reference
 249                                  * count on our parent.
 250                                  */
 251                                 dmat = parent;
 252                         } else
 253                                 dmat = NULL;
 254                 }
 255         }
 256         return (0);
 257 }
 258
 259 /*
 260  * Allocate a handle for mapping from kva/uva/physical
 261  * address space into bus device space.
 262  */
 263 int
 264 bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 265 {
 266         int error;
 267
 268         error = 0;
 269
 270         if (dmat->segments == NULL) {
 271                 KKASSERT(dmat->nsegments && dmat->nsegments < 16384);
 272                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 273                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 274         }
 275
 276         if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
 277                 /* Must bounce */
 278                 int maxpages;
 279
 280                 *mapp = kmalloc(sizeof(**mapp), M_DEVBUF, M_INTWAIT | M_ZERO);
 281
 282                 /* Initialize the new map */
 283                 STAILQ_INIT(&((*mapp)->bpages));
 284                 /*
 285                  * Attempt to add pages to our pool on a per-instance
 286                  * basis up to a sane limit.
 287                  */
 288                 maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
 289                 if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
 290                  || (dmat->map_count > 0
 291                   && total_bpages < maxpages)) {
 292                         int pages;
 293
 294                         if (dmat->lowaddr > bounce_lowaddr) {
 295                                 /*
 296                                  * Go through the pool and kill any pages
 297                                  * that don't reside below lowaddr.
 298                                  */
 299                                 panic("bus_dmamap_create: page reallocation "
 300                                       "not implemented");
 301                         }
 302
 303                         pages = MAX(atop(dmat->maxsize), 1);
 304                         pages = MIN(maxpages - total_bpages, pages);
 305                         pages = MAX(pages, 1);
 306                         if (alloc_bounce_pages(dmat, pages) < pages)
 307                                 error = ENOMEM;
 308
 309                         if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
 310                                 if (error == 0)
 311                                         dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
 312                         } else {
 313                                 error = 0;
 314                         }
 315                 }
 316         } else {
 317                 *mapp = NULL;
 318         }
 319         if (error == 0)
 320                 dmat->map_count++;
 321         return (error);
 322 }
 323
 324 /*
 325  * Destroy a handle for mapping from kva/uva/physical
 326  * address space into bus device space.
 327  */
 328 int
 329 bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 330 {
 331         if (map != NULL) {
 332                 if (STAILQ_FIRST(&map->bpages) != NULL)
 333                         return (EBUSY);
 334                 kfree(map, M_DEVBUF);
 335         }
 336         dmat->map_count--;
 337         return (0);
 338 }
 339
 340 /*
 341  * Allocate a piece of memory that can be efficiently mapped into
 342  * bus device space based on the constraints lited in the dma tag.
 343  *
 344  * mapp is degenerate.  By definition this allocation should not require
 345  * bounce buffers so do not allocate a dma map.
 346  */
 347 int
 348 bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 349                  bus_dmamap_t *mapp)
 350 {
 351         int mflags;
 352
 353         /* If we succeed, no mapping/bouncing will be required */
 354         *mapp = NULL;
 355
 356         if (dmat->segments == NULL) {
 357                 KKASSERT(dmat->nsegments < 16384);
 358                 dmat->segments = kmalloc(sizeof(bus_dma_segment_t) *
 359                                         dmat->nsegments, M_DEVBUF, M_INTWAIT);
 360         }
 361
 362         if (flags & BUS_DMA_NOWAIT)
 363                 mflags = M_NOWAIT;
 364         else
 365                 mflags = M_WAITOK;
 366         if (flags & BUS_DMA_ZERO)
 367                 mflags |= M_ZERO;
 368
 369         if ((dmat->maxsize <= PAGE_SIZE) &&
 370             dmat->lowaddr >= ptoa(Maxmem)) {
 371                 *vaddr = kmalloc(dmat->maxsize, M_DEVBUF, mflags);
 372                 /*
 373                  * XXX Check whether the allocation crossed a page boundary
 374                  * and retry with power-of-2 alignment in that case.
 375                  */
 376                 if ((((intptr_t)*vaddr) & PAGE_MASK) !=
 377                     (((intptr_t)*vaddr + dmat->maxsize) & PAGE_MASK)) {
 378                         size_t size;
 379
 380                         kfree(*vaddr, M_DEVBUF);
 381                         /* XXX check for overflow? */
 382                         for (size = 1; size <= dmat->maxsize; size <<= 1)
 383                                 ;
 384                         *vaddr = kmalloc(size, M_DEVBUF, mflags);
 385                 }
 386         } else {
 387                 /*
 388                  * XXX Use Contigmalloc until it is merged into this facility
 389                  *     and handles multi-seg allocations.  Nobody is doing
 390                  *     multi-seg allocations yet though.
 391                  */
 392                 *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
 393                     0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
 394                     dmat->boundary);
 395         }
 396         if (*vaddr == NULL)
 397                 return (ENOMEM);
 398         return (0);
 399 }
 400
 401 /*
 402  * Free a piece of memory and it's allociated dmamap, that was allocated
 403  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 404  */
 405 void
 406 bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 407 {
 408         /*
 409          * dmamem does not need to be bounced, so the map should be
 410          * NULL
 411          */
 412         if (map != NULL)
 413                 panic("bus_dmamem_free: Invalid map freed\n");
 414         if ((dmat->maxsize <= PAGE_SIZE) &&
 415             dmat->lowaddr >= ptoa(Maxmem))
 416                 kfree(vaddr, M_DEVBUF);
 417         else
 418                 contigfree(vaddr, dmat->maxsize, M_DEVBUF);
 419 }
 420
 421 #define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
 422
 423 /*
 424  * Map the buffer buf into bus space using the dmamap map.
 425  */
 426 int
 427 bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 428                 bus_size_t buflen, bus_dmamap_callback_t *callback,
 429                 void *callback_arg, int flags)
 430 {
 431         vm_offset_t vaddr;
 432         vm_paddr_t paddr, nextpaddr;
 433         bus_dma_segment_t *sg;
 434         bus_addr_t bmask;
 435         int seg, error;
 436
 437         if (map == NULL)
 438                 map = &nobounce_dmamap;
 439
 440         error = 0;
 441         /*
 442          * If we are being called during a callback, pagesneeded will
 443          * be non-zero, so we can avoid doing the work twice.
 444          */
 445         if ((dmat->flags & BUS_DMA_COULD_BOUNCE) &&
 446             map->pagesneeded == 0) {
 447                 vm_offset_t vendaddr;
 448
 449                 /*
 450                  * Count the number of bounce pages
 451                  * needed in order to complete this transfer
 452                  */
 453                 vaddr = trunc_page((vm_offset_t)buf);
 454                 vendaddr = (vm_offset_t)buf + buflen;
 455
 456                 while (vaddr < vendaddr) {
 457                         paddr = pmap_kextract(vaddr);
 458                         if (run_filter(dmat, paddr) != 0)
 459                                 map->pagesneeded++;
 460                         vaddr += PAGE_SIZE;
 461                 }
 462         }
 463
 464         /* Reserve Necessary Bounce Pages */
 465         if (map->pagesneeded != 0) {
 466                 crit_enter();
 467                 if (reserve_bounce_pages(dmat, map) != 0) {
 468                         /* Queue us for resources */
 469                         map->dmat = dmat;
 470                         map->buf = buf;
 471                         map->buflen = buflen;
 472                         map->callback = callback;
 473                         map->callback_arg = callback_arg;
 474
 475                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 476                         crit_exit();
 477
 478                         return (EINPROGRESS);
 479                 }
 480                 crit_exit();
 481         }
 482
 483         vaddr = (vm_offset_t)buf;
 484         sg = dmat->segments;
 485         seg = 1;
 486         sg->ds_len = 0;
 487         nextpaddr = 0;
 488         bmask = ~(dmat->boundary - 1);  /* note: will be 0 if boundary is 0 */
 489
 490         /* force at least one segment */
 491         do {
 492                 bus_size_t size;
 493
 494                 /*
 495                  * Per-page main loop
 496                  */
 497                 paddr = pmap_kextract(vaddr);
 498                 size = PAGE_SIZE - (paddr & PAGE_MASK);
 499                 if (size > buflen)
 500                         size = buflen;
 501                 if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
 502                         /*
 503                          * note: this paddr has the same in-page offset
 504                          * as vaddr and thus the paddr above, so the
 505                          * size does not have to be recalculated
 506                          */
 507                         paddr = add_bounce_page(dmat, map, vaddr, size);
 508                 }
 509
 510                 /*
 511                  * Fill in the bus_dma_segment
 512                  */
 513                 if (sg->ds_len == 0) {
 514                         sg->ds_addr = paddr;
 515                         sg->ds_len = size;
 516                 } else if (paddr == nextpaddr) {
 517                         sg->ds_len += size;
 518                 } else {
 519                         sg++;
 520                         seg++;
 521                         if (seg > dmat->nsegments)
 522                                 break;
 523                         sg->ds_addr = paddr;
 524                         sg->ds_len = size;
 525                 }
 526                 nextpaddr = paddr + size;
 527
 528                 /*
 529                  * Handle maxsegsz and boundary issues with a nested loop
 530                  */
 531                 for (;;) {
 532                         bus_size_t tmpsize;
 533
 534                         /*
 535                          * Limit to the boundary and maximum segment size
 536                          */
 537                         if (((nextpaddr - 1) ^ sg->ds_addr) & bmask) {
 538                                 tmpsize = dmat->boundary -
 539                                           (sg->ds_addr & ~bmask);
 540                                 if (tmpsize > dmat->maxsegsz)
 541                                         tmpsize = dmat->maxsegsz;
 542                                 KKASSERT(tmpsize < sg->ds_len);
 543                         } else if (sg->ds_len > dmat->maxsegsz) {
 544                                 tmpsize = dmat->maxsegsz;
 545                         } else {
 546                                 break;
 547                         }
 548
 549                         /*
 550                          * Futz, split the data into a new segment.
 551                          */
 552                         if (seg >= dmat->nsegments)
 553                                 goto fail;
 554                         sg[1].ds_len = sg[0].ds_len - tmpsize;
 555                         sg[1].ds_addr = sg[0].ds_addr + tmpsize;
 556                         sg[0].ds_len = tmpsize;
 557                         sg++;
 558                         seg++;
 559                 }
 560
 561                 /*
 562                  * Adjust for loop
 563                  */
 564                 buflen -= size;
 565                 vaddr += size;
 566         } while (buflen > 0);
 567
 568 fail:
 569         if (buflen != 0) {
 570                 kprintf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
 571                        (u_long)buflen);
 572                 error = EFBIG;
 573         }
 574
 575         (*callback)(callback_arg, dmat->segments, seg, error);
 576
 577         return (0);
 578 }
 579
 580 /*
 581  * Utility function to load a linear buffer.  lastaddrp holds state
 582  * between invocations (for multiple-buffer loads).  segp contains
 583  * the starting segment on entrace, and the ending segment on exit.
 584  * first indicates if this is the first invocation of this function.
 585  */
 586 static int
 587 _bus_dmamap_load_buffer(bus_dma_tag_t dmat,
 588                         void *buf, bus_size_t buflen,
 589                         struct thread *td,
 590                         int flags,
 591                         vm_offset_t *lastaddrp,
 592                         int *segp,
 593                         int first)
 594 {
 595         bus_dma_segment_t *segs;
 596         bus_size_t sgsize;
 597         bus_addr_t curaddr, lastaddr, baddr, bmask;
 598         vm_offset_t vaddr = (vm_offset_t)buf;
 599         int seg;
 600         pmap_t pmap;
 601
 602         if (td->td_proc != NULL)
 603                 pmap = vmspace_pmap(td->td_proc->p_vmspace);
 604         else
 605                 pmap = NULL;
 606
 607         segs = dmat->segments;
 608         lastaddr = *lastaddrp;
 609         bmask  = ~(dmat->boundary - 1);
 610
 611         for (seg = *segp; buflen > 0 ; ) {
 612                 /*
 613                  * Get the physical address for this segment.
 614                  */
 615                 if (pmap)
 616                         curaddr = pmap_extract(pmap, vaddr);
 617                 else
 618                         curaddr = pmap_kextract(vaddr);
 619
 620                 /*
 621                  * Compute the segment size, and adjust counts.
 622                  */
 623                 sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
 624                 if (buflen < sgsize)
 625                         sgsize = buflen;
 626
 627                 /*
 628                  * Make sure we don't cross any boundaries.
 629                  */
 630                 if (dmat->boundary > 0) {
 631                         baddr = (curaddr + dmat->boundary) & bmask;
 632                         if (sgsize > (baddr - curaddr))
 633                                 sgsize = (baddr - curaddr);
 634                 }
 635
 636                 /*
 637                  * Insert chunk into a segment, coalescing with
 638                  * previous segment if possible.
 639                  */
 640                 if (first) {
 641                         segs[seg].ds_addr = curaddr;
 642                         segs[seg].ds_len = sgsize;
 643                         first = 0;
 644                 } else {
 645                         if (curaddr == lastaddr &&
 646                             (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
 647                             (dmat->boundary == 0 ||
 648                              (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 649                                 segs[seg].ds_len += sgsize;
 650                         else {
 651                                 if (++seg >= dmat->nsegments)
 652                                         break;
 653                                 segs[seg].ds_addr = curaddr;
 654                                 segs[seg].ds_len = sgsize;
 655                         }
 656                 }
 657
 658                 lastaddr = curaddr + sgsize;
 659                 vaddr += sgsize;
 660                 buflen -= sgsize;
 661         }
 662
 663         *segp = seg;
 664         *lastaddrp = lastaddr;
 665
 666         /*
 667          * Did we fit?
 668          */
 669         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 670 }
 671
 672 /*
 673  * Like _bus_dmamap_load(), but for mbufs.
 674  */
 675 int
 676 bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
 677                      struct mbuf *m0,
 678                      bus_dmamap_callback2_t *callback, void *callback_arg,
 679                      int flags)
 680 {
 681         int nsegs, error;
 682
 683         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 684                 ("bus_dmamap_load_mbuf: No support for bounce pages!"));
 685         KASSERT(m0->m_flags & M_PKTHDR,
 686                 ("bus_dmamap_load_mbuf: no packet header"));
 687
 688         nsegs = 0;
 689         error = 0;
 690         if (m0->m_pkthdr.len <= dmat->maxsize) {
 691                 int first = 1;
 692                 vm_offset_t lastaddr = 0;
 693                 struct mbuf *m;
 694
 695                 for (m = m0; m != NULL && error == 0; m = m->m_next) {
 696                         if ( m->m_len == 0 )
 697                                 continue;
 698                         error = _bus_dmamap_load_buffer(dmat,
 699                                         m->m_data, m->m_len,
 700                                         curthread, flags, &lastaddr,
 701                                         &nsegs, first);
 702                         first = 0;
 703                 }
 704         } else {
 705                 error = EINVAL;
 706         }
 707
 708         if (error) {
 709                 /* force "no valid mappings" in callback */
 710                 (*callback)(callback_arg, dmat->segments, 0, 0, error);
 711         } else {
 712                 (*callback)(callback_arg, dmat->segments,
 713                             nsegs+1, m0->m_pkthdr.len, error);
 714         }
 715         return (error);
 716 }
 717
 718 /*
 719  * Like _bus_dmamap_load(), but for uios.
 720  */
 721 int
 722 bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
 723                     struct uio *uio,
 724                     bus_dmamap_callback2_t *callback, void *callback_arg,
 725                     int flags)
 726 {
 727         vm_offset_t lastaddr;
 728         int nsegs, error, first, i;
 729         bus_size_t resid;
 730         struct iovec *iov;
 731         struct thread *td = NULL;
 732
 733         KASSERT(dmat->lowaddr >= ptoa(Maxmem) || map != NULL,
 734                 ("bus_dmamap_load_uio: No support for bounce pages!"));
 735
 736         resid = uio->uio_resid;
 737         iov = uio->uio_iov;
 738
 739         if (uio->uio_segflg == UIO_USERSPACE) {
 740                 td = uio->uio_td;
 741                 KASSERT(td != NULL && td->td_proc != NULL,
 742                         ("bus_dmamap_load_uio: USERSPACE but no proc"));
 743         }
 744
 745         nsegs = 0;
 746         error = 0;
 747         first = 1;
 748         for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
 749                 /*
 750                  * Now at the first iovec to load.  Load each iovec
 751                  * until we have exhausted the residual count.
 752                  */
 753                 bus_size_t minlen =
 754                         resid < iov[i].iov_len ? resid : iov[i].iov_len;
 755                 caddr_t addr = (caddr_t) iov[i].iov_base;
 756
 757                 error = _bus_dmamap_load_buffer(dmat,
 758                                 addr, minlen,
 759                                 td, flags, &lastaddr, &nsegs, first);
 760                 first = 0;
 761
 762                 resid -= minlen;
 763         }
 764
 765         if (error) {
 766                 /* force "no valid mappings" in callback */
 767                 (*callback)(callback_arg, dmat->segments, 0, 0, error);
 768         } else {
 769                 (*callback)(callback_arg, dmat->segments,
 770                             nsegs+1, uio->uio_resid, error);
 771         }
 772         return (error);
 773 }
 774
 775 /*
 776  * Release the mapping held by map.
 777  */
 778 void
 779 _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 780 {
 781         struct bounce_page *bpage;
 782
 783         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 784                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 785                 free_bounce_page(dmat, bpage);
 786         }
 787 }
 788
 789 void
 790 _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
 791 {
 792         struct bounce_page *bpage;
 793
 794         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 795                 /*
 796                  * Handle data bouncing.  We might also
 797                  * want to add support for invalidating
 798                  * the caches on broken hardware
 799                  */
 800                 switch (op) {
 801                 case BUS_DMASYNC_PREWRITE:
 802                         while (bpage != NULL) {
 803                                 bcopy((void *)bpage->datavaddr,
 804                                       (void *)bpage->vaddr,
 805                                       bpage->datacount);
 806                                 bpage = STAILQ_NEXT(bpage, links);
 807                         }
 808                         break;
 809
 810                 case BUS_DMASYNC_POSTREAD:
 811                         while (bpage != NULL) {
 812                                 bcopy((void *)bpage->vaddr,
 813                                       (void *)bpage->datavaddr,
 814                                       bpage->datacount);
 815                                 bpage = STAILQ_NEXT(bpage, links);
 816                         }
 817                         break;
 818
 819                 case BUS_DMASYNC_PREREAD:
 820                 case BUS_DMASYNC_POSTWRITE:
 821                         /* No-ops */
 822                         break;
 823                 }
 824         }
 825 }
 826
 827 static int
 828 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 829 {
 830         int count;
 831
 832         count = 0;
 833         if (total_bpages == 0) {
 834                 STAILQ_INIT(&bounce_page_list);
 835                 STAILQ_INIT(&bounce_map_waitinglist);
 836                 STAILQ_INIT(&bounce_map_callbacklist);
 837         }
 838
 839         while (numpages > 0) {
 840                 struct bounce_page *bpage;
 841
 842                 bpage = kmalloc(sizeof(*bpage), M_DEVBUF, M_INTWAIT | M_ZERO);
 843
 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 }