sys/x86/x86/busdma_bounce.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
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/malloc.h>
  33 #include <sys/bus.h>
  34 #include <sys/interrupt.h>
  35 #include <sys/kernel.h>
  36 #include <sys/ktr.h>
  37 #include <sys/lock.h>
  38 #include <sys/proc.h>
  39 #include <sys/memdesc.h>
  40 #include <sys/mutex.h>
  41 #include <sys/sysctl.h>
  42 #include <sys/uio.h>
  43
  44 #include <vm/vm.h>
  45 #include <vm/vm_extern.h>
  46 #include <vm/vm_kern.h>
  47 #include <vm/vm_page.h>
  48 #include <vm/vm_map.h>
  49
  50 #include <machine/atomic.h>
  51 #include <machine/bus.h>
  52 #include <machine/md_var.h>
  53 #include <machine/specialreg.h>
  54 #include <x86/include/busdma_impl.h>
  55
  56 #ifdef __i386__
  57 #define MAX_BPAGES 512
  58 #else
  59 #define MAX_BPAGES 8192
  60 #endif
  61
  62 enum {
  63         BUS_DMA_COULD_BOUNCE    = 0x01,
  64         BUS_DMA_MIN_ALLOC_COMP  = 0x02,
  65         BUS_DMA_KMEM_ALLOC      = 0x04,
  66 };
  67
  68 struct bounce_zone;
  69
  70 struct bus_dma_tag {
  71         struct bus_dma_tag_common common;
  72         int                     map_count;
  73         int                     bounce_flags;
  74         bus_dma_segment_t       *segments;
  75         struct bounce_zone      *bounce_zone;
  76 };
  77
  78 struct bounce_page {
  79         vm_offset_t     vaddr;          /* kva of bounce buffer */
  80         bus_addr_t      busaddr;        /* Physical address */
  81         vm_offset_t     datavaddr;      /* kva of client data */
  82         bus_addr_t      dataaddr;       /* client physical address */
  83         bus_size_t      datacount;      /* client data count */
  84         STAILQ_ENTRY(bounce_page) links;
  85 };
  86
  87 int busdma_swi_pending;
  88
  89 struct bounce_zone {
  90         STAILQ_ENTRY(bounce_zone) links;
  91         STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
  92         int             total_bpages;
  93         int             free_bpages;
  94         int             reserved_bpages;
  95         int             active_bpages;
  96         int             total_bounced;
  97         int             total_deferred;
  98         int             map_count;
  99         bus_size_t      alignment;
 100         bus_addr_t      lowaddr;
 101         char            zoneid[8];
 102         char            lowaddrid[20];
 103         struct sysctl_ctx_list sysctl_tree;
 104         struct sysctl_oid *sysctl_tree_top;
 105 };
 106
 107 static struct mtx bounce_lock;
 108 static int total_bpages;
 109 static int busdma_zonecount;
 110 static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
 111
 112 static SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
 113 SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
 114            "Total bounce pages");
 115
 116 struct bus_dmamap {
 117         struct bp_list         bpages;
 118         int                    pagesneeded;
 119         int                    pagesreserved;
 120         bus_dma_tag_t          dmat;
 121         struct memdesc         mem;
 122         bus_dmamap_callback_t *callback;
 123         void                  *callback_arg;
 124         STAILQ_ENTRY(bus_dmamap) links;
 125 };
 126
 127 static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
 128 static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
 129 static struct bus_dmamap nobounce_dmamap;
 130
 131 static void init_bounce_pages(void *dummy);
 132 static int alloc_bounce_zone(bus_dma_tag_t dmat);
 133 static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 134 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 135                                 int commit);
 136 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
 137                                   vm_offset_t vaddr, bus_addr_t addr,
 138                                   bus_size_t size);
 139 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 140 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 141 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 142                                     pmap_t pmap, void *buf, bus_size_t buflen,
 143                                     int flags);
 144 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 145                                    vm_paddr_t buf, bus_size_t buflen,
 146                                    int flags);
 147 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 148                                      int flags);
 149
 150 #ifdef XEN
 151 #undef pmap_kextract
 152 #define pmap_kextract pmap_kextract_ma
 153 #endif
 154
 155 /*
 156  * Allocate a device specific dma_tag.
 157  */
 158 static int
 159 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 160     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 161     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 162     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 163     void *lockfuncarg, bus_dma_tag_t *dmat)
 164 {
 165         bus_dma_tag_t newtag;
 166         int error;
 167
 168         *dmat = NULL;
 169         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 170             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 171             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 172             sizeof (struct bus_dma_tag), (void **)&newtag);
 173         if (error != 0)
 174                 return (error);
 175
 176         newtag->common.impl = &bus_dma_bounce_impl;
 177         newtag->map_count = 0;
 178         newtag->segments = NULL;
 179
 180         if (parent != NULL && ((newtag->common.filter != NULL) ||
 181             ((parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0)))
 182                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 183
 184         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 185             newtag->common.alignment > 1)
 186                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 187
 188         if (((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 189             (flags & BUS_DMA_ALLOCNOW) != 0) {
 190                 struct bounce_zone *bz;
 191
 192                 /* Must bounce */
 193                 if ((error = alloc_bounce_zone(newtag)) != 0) {
 194                         free(newtag, M_DEVBUF);
 195                         return (error);
 196                 }
 197                 bz = newtag->bounce_zone;
 198
 199                 if (ptoa(bz->total_bpages) < maxsize) {
 200                         int pages;
 201
 202                         pages = atop(maxsize) - bz->total_bpages;
 203
 204                         /* Add pages to our bounce pool */
 205                         if (alloc_bounce_pages(newtag, pages) < pages)
 206                                 error = ENOMEM;
 207                 }
 208                 /* Performed initial allocation */
 209                 newtag->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 210         } else
 211                 error = 0;
 212
 213         if (error != 0)
 214                 free(newtag, M_DEVBUF);
 215         else
 216                 *dmat = newtag;
 217         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 218             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 219             error);
 220         return (error);
 221 }
 222
 223 static int
 224 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 225 {
 226         bus_dma_tag_t dmat_copy, parent;
 227         int error;
 228
 229         error = 0;
 230         dmat_copy = dmat;
 231
 232         if (dmat != NULL) {
 233                 if (dmat->map_count != 0) {
 234                         error = EBUSY;
 235                         goto out;
 236                 }
 237                 while (dmat != NULL) {
 238                         parent = (bus_dma_tag_t)dmat->common.parent;
 239                         atomic_subtract_int(&dmat->common.ref_count, 1);
 240                         if (dmat->common.ref_count == 0) {
 241                                 if (dmat->segments != NULL)
 242                                         free(dmat->segments, M_DEVBUF);
 243                                 free(dmat, M_DEVBUF);
 244                                 /*
 245                                  * Last reference count, so
 246                                  * release our reference
 247                                  * count on our parent.
 248                                  */
 249                                 dmat = parent;
 250                         } else
 251                                 dmat = NULL;
 252                 }
 253         }
 254 out:
 255         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 256         return (error);
 257 }
 258
 259 /*
 260  * Allocate a handle for mapping from kva/uva/physical
 261  * address space into bus device space.
 262  */
 263 static int
 264 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 265 {
 266         struct bounce_zone *bz;
 267         int error, maxpages, pages;
 268
 269         error = 0;
 270
 271         if (dmat->segments == NULL) {
 272                 dmat->segments = (bus_dma_segment_t *)malloc(
 273                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 274                     M_DEVBUF, M_NOWAIT);
 275                 if (dmat->segments == NULL) {
 276                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 277                             __func__, dmat, ENOMEM);
 278                         return (ENOMEM);
 279                 }
 280         }
 281
 282         /*
 283          * Bouncing might be required if the driver asks for an active
 284          * exclusion region, a data alignment that is stricter than 1, and/or
 285          * an active address boundary.
 286          */
 287         if (dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) {
 288                 /* Must bounce */
 289                 if (dmat->bounce_zone == NULL) {
 290                         if ((error = alloc_bounce_zone(dmat)) != 0)
 291                                 return (error);
 292                 }
 293                 bz = dmat->bounce_zone;
 294
 295                 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 296                     M_NOWAIT | M_ZERO);
 297                 if (*mapp == NULL) {
 298                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 299                             __func__, dmat, ENOMEM);
 300                         return (ENOMEM);
 301                 }
 302
 303                 /* Initialize the new map */
 304                 STAILQ_INIT(&((*mapp)->bpages));
 305
 306                 /*
 307                  * Attempt to add pages to our pool on a per-instance
 308                  * basis up to a sane limit.
 309                  */
 310                 if (dmat->common.alignment > 1)
 311                         maxpages = MAX_BPAGES;
 312                 else
 313                         maxpages = MIN(MAX_BPAGES, Maxmem -
 314                             atop(dmat->common.lowaddr));
 315                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 316                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 317                         pages = MAX(atop(dmat->common.maxsize), 1);
 318                         pages = MIN(maxpages - bz->total_bpages, pages);
 319                         pages = MAX(pages, 1);
 320                         if (alloc_bounce_pages(dmat, pages) < pages)
 321                                 error = ENOMEM;
 322                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 323                             == 0) {
 324                                 if (error == 0) {
 325                                         dmat->bounce_flags |=
 326                                             BUS_DMA_MIN_ALLOC_COMP;
 327                                 }
 328                         } else
 329                                 error = 0;
 330                 }
 331                 bz->map_count++;
 332         } else {
 333                 *mapp = NULL;
 334         }
 335         if (error == 0)
 336                 dmat->map_count++;
 337         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 338             __func__, dmat, dmat->common.flags, error);
 339         return (error);
 340 }
 341
 342 /*
 343  * Destroy a handle for mapping from kva/uva/physical
 344  * address space into bus device space.
 345  */
 346 static int
 347 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 348 {
 349
 350         if (map != NULL && map != &nobounce_dmamap) {
 351                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 352                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 353                             __func__, dmat, EBUSY);
 354                         return (EBUSY);
 355                 }
 356                 if (dmat->bounce_zone)
 357                         dmat->bounce_zone->map_count--;
 358                 free(map, M_DEVBUF);
 359         }
 360         dmat->map_count--;
 361         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 362         return (0);
 363 }
 364
 365
 366 /*
 367  * Allocate a piece of memory that can be efficiently mapped into
 368  * bus device space based on the constraints lited in the dma tag.
 369  * A dmamap to for use with dmamap_load is also allocated.
 370  */
 371 static int
 372 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 373     bus_dmamap_t *mapp)
 374 {
 375         vm_memattr_t attr;
 376         int mflags;
 377
 378         if (flags & BUS_DMA_NOWAIT)
 379                 mflags = M_NOWAIT;
 380         else
 381                 mflags = M_WAITOK;
 382
 383         /* If we succeed, no mapping/bouncing will be required */
 384         *mapp = NULL;
 385
 386         if (dmat->segments == NULL) {
 387                 dmat->segments = (bus_dma_segment_t *)malloc(
 388                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 389                     M_DEVBUF, mflags);
 390                 if (dmat->segments == NULL) {
 391                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 392                             __func__, dmat, dmat->common.flags, ENOMEM);
 393                         return (ENOMEM);
 394                 }
 395         }
 396         if (flags & BUS_DMA_ZERO)
 397                 mflags |= M_ZERO;
 398         if (flags & BUS_DMA_NOCACHE)
 399                 attr = VM_MEMATTR_UNCACHEABLE;
 400         else
 401                 attr = VM_MEMATTR_DEFAULT;
 402
 403         /*
 404          * XXX:
 405          * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
 406          * alignment guarantees of malloc need to be nailed down, and the
 407          * code below should be rewritten to take that into account.
 408          *
 409          * In the meantime, we'll warn the user if malloc gets it wrong.
 410          */
 411         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 412            (dmat->common.alignment < dmat->common.maxsize) &&
 413             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 414             attr == VM_MEMATTR_DEFAULT) {
 415                 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
 416         } else if (dmat->common.nsegments >= btoc(dmat->common.maxsize) &&
 417             dmat->common.alignment <= PAGE_SIZE &&
 418             (dmat->common.boundary == 0 ||
 419             dmat->common.boundary >= dmat->common.lowaddr)) {
 420                 /* Page-based multi-segment allocations allowed */
 421                 *vaddr = (void *)kmem_alloc_attr(kernel_arena,
 422                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 423                     attr);
 424                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 425         } else {
 426                 *vaddr = (void *)kmem_alloc_contig(kernel_arena,
 427                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 428                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 429                     dmat->common.boundary, attr);
 430                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 431         }
 432         if (*vaddr == NULL) {
 433                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 434                     __func__, dmat, dmat->common.flags, ENOMEM);
 435                 return (ENOMEM);
 436         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 437                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 438         }
 439         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 440             __func__, dmat, dmat->common.flags, 0);
 441         return (0);
 442 }
 443
 444 /*
 445  * Free a piece of memory and it's allociated dmamap, that was allocated
 446  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 447  */
 448 static void
 449 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 450 {
 451         /*
 452          * dmamem does not need to be bounced, so the map should be
 453          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 454          * was used and set if kmem_alloc_contig() was used.
 455          */
 456         if (map != NULL)
 457                 panic("bus_dmamem_free: Invalid map freed\n");
 458         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 459                 free(vaddr, M_DEVBUF);
 460         else
 461                 kmem_free(kernel_arena, (vm_offset_t)vaddr,
 462                     dmat->common.maxsize);
 463         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 464             dmat->bounce_flags);
 465 }
 466
 467 static void
 468 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 469     bus_size_t buflen, int flags)
 470 {
 471         bus_addr_t curaddr;
 472         bus_size_t sgsize;
 473
 474         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 475                 /*
 476                  * Count the number of bounce pages
 477                  * needed in order to complete this transfer
 478                  */
 479                 curaddr = buf;
 480                 while (buflen != 0) {
 481                         sgsize = MIN(buflen, dmat->common.maxsegsz);
 482                         if (bus_dma_run_filter(&dmat->common, curaddr)) {
 483                                 sgsize = MIN(sgsize, PAGE_SIZE);
 484                                 map->pagesneeded++;
 485                         }
 486                         curaddr += sgsize;
 487                         buflen -= sgsize;
 488                 }
 489                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 490         }
 491 }
 492
 493 static void
 494 _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
 495     void *buf, bus_size_t buflen, int flags)
 496 {
 497         vm_offset_t vaddr;
 498         vm_offset_t vendaddr;
 499         bus_addr_t paddr;
 500         bus_size_t sg_len;
 501
 502         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 503                 CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
 504                     "alignment= %d", dmat->common.lowaddr,
 505                     ptoa((vm_paddr_t)Maxmem),
 506                     dmat->common.boundary, dmat->common.alignment);
 507                 CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
 508                     map, &nobounce_dmamap, map->pagesneeded);
 509                 /*
 510                  * Count the number of bounce pages
 511                  * needed in order to complete this transfer
 512                  */
 513                 vaddr = (vm_offset_t)buf;
 514                 vendaddr = (vm_offset_t)buf + buflen;
 515
 516                 while (vaddr < vendaddr) {
 517                         sg_len = PAGE_SIZE - ((vm_offset_t)vaddr & PAGE_MASK);
 518                         if (pmap == kernel_pmap)
 519                                 paddr = pmap_kextract(vaddr);
 520                         else
 521                                 paddr = pmap_extract(pmap, vaddr);
 522                         if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
 523                                 sg_len = roundup2(sg_len,
 524                                     dmat->common.alignment);
 525                                 map->pagesneeded++;
 526                         }
 527                         vaddr += sg_len;
 528                 }
 529                 CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
 530         }
 531 }
 532
 533 static int
 534 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 535 {
 536
 537         /* Reserve Necessary Bounce Pages */
 538         mtx_lock(&bounce_lock);
 539         if (flags & BUS_DMA_NOWAIT) {
 540                 if (reserve_bounce_pages(dmat, map, 0) != 0) {
 541                         mtx_unlock(&bounce_lock);
 542                         return (ENOMEM);
 543                 }
 544         } else {
 545                 if (reserve_bounce_pages(dmat, map, 1) != 0) {
 546                         /* Queue us for resources */
 547                         STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
 548                         mtx_unlock(&bounce_lock);
 549                         return (EINPROGRESS);
 550                 }
 551         }
 552         mtx_unlock(&bounce_lock);
 553
 554         return (0);
 555 }
 556
 557 /*
 558  * Add a single contiguous physical range to the segment list.
 559  */
 560 static int
 561 _bus_dmamap_addseg(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t curaddr,
 562     bus_size_t sgsize, bus_dma_segment_t *segs, int *segp)
 563 {
 564         bus_addr_t baddr, bmask;
 565         int seg;
 566
 567         /*
 568          * Make sure we don't cross any boundaries.
 569          */
 570         bmask = ~(dmat->common.boundary - 1);
 571         if (dmat->common.boundary > 0) {
 572                 baddr = (curaddr + dmat->common.boundary) & bmask;
 573                 if (sgsize > (baddr - curaddr))
 574                         sgsize = (baddr - curaddr);
 575         }
 576
 577         /*
 578          * Insert chunk into a segment, coalescing with
 579          * previous segment if possible.
 580          */
 581         seg = *segp;
 582         if (seg == -1) {
 583                 seg = 0;
 584                 segs[seg].ds_addr = curaddr;
 585                 segs[seg].ds_len = sgsize;
 586         } else {
 587                 if (curaddr == segs[seg].ds_addr + segs[seg].ds_len &&
 588                     (segs[seg].ds_len + sgsize) <= dmat->common.maxsegsz &&
 589                     (dmat->common.boundary == 0 ||
 590                      (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
 591                         segs[seg].ds_len += sgsize;
 592                 else {
 593                         if (++seg >= dmat->common.nsegments)
 594                                 return (0);
 595                         segs[seg].ds_addr = curaddr;
 596                         segs[seg].ds_len = sgsize;
 597                 }
 598         }
 599         *segp = seg;
 600         return (sgsize);
 601 }
 602
 603 /*
 604  * Utility function to load a physical buffer.  segp contains
 605  * the starting segment on entrace, and the ending segment on exit.
 606  */
 607 static int
 608 bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 609     vm_paddr_t buf, bus_size_t buflen, int flags, bus_dma_segment_t *segs,
 610     int *segp)
 611 {
 612         bus_size_t sgsize;
 613         bus_addr_t curaddr;
 614         int error;
 615
 616         if (map == NULL)
 617                 map = &nobounce_dmamap;
 618
 619         if (segs == NULL)
 620                 segs = dmat->segments;
 621
 622         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 623                 _bus_dmamap_count_phys(dmat, map, buf, buflen, flags);
 624                 if (map->pagesneeded != 0) {
 625                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 626                         if (error)
 627                                 return (error);
 628                 }
 629         }
 630
 631         while (buflen > 0) {
 632                 curaddr = buf;
 633                 sgsize = MIN(buflen, dmat->common.maxsegsz);
 634                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 635                     map->pagesneeded != 0 &&
 636                     bus_dma_run_filter(&dmat->common, curaddr)) {
 637                         sgsize = MIN(sgsize, PAGE_SIZE);
 638                         curaddr = add_bounce_page(dmat, map, 0, curaddr,
 639                             sgsize);
 640                 }
 641                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 642                     segp);
 643                 if (sgsize == 0)
 644                         break;
 645                 buf += sgsize;
 646                 buflen -= sgsize;
 647         }
 648
 649         /*
 650          * Did we fit?
 651          */
 652         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 653 }
 654
 655 /*
 656  * Utility function to load a linear buffer.  segp contains
 657  * the starting segment on entrace, and the ending segment on exit.
 658  */
 659 static int
 660 bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
 661     bus_size_t buflen, pmap_t pmap, int flags, bus_dma_segment_t *segs,
 662     int *segp)
 663 {
 664         bus_size_t sgsize, max_sgsize;
 665         bus_addr_t curaddr;
 666         vm_offset_t vaddr;
 667         int error;
 668
 669         if (map == NULL)
 670                 map = &nobounce_dmamap;
 671
 672         if (segs == NULL)
 673                 segs = dmat->segments;
 674
 675         if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
 676                 _bus_dmamap_count_pages(dmat, map, pmap, buf, buflen, flags);
 677                 if (map->pagesneeded != 0) {
 678                         error = _bus_dmamap_reserve_pages(dmat, map, flags);
 679                         if (error)
 680                                 return (error);
 681                 }
 682         }
 683
 684         vaddr = (vm_offset_t)buf;
 685         while (buflen > 0) {
 686                 /*
 687                  * Get the physical address for this segment.
 688                  */
 689                 if (pmap == kernel_pmap)
 690                         curaddr = pmap_kextract(vaddr);
 691                 else
 692                         curaddr = pmap_extract(pmap, vaddr);
 693
 694                 /*
 695                  * Compute the segment size, and adjust counts.
 696                  */
 697                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 698                 sgsize = PAGE_SIZE - ((vm_offset_t)curaddr & PAGE_MASK);
 699                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 700                     map->pagesneeded != 0 &&
 701                     bus_dma_run_filter(&dmat->common, curaddr)) {
 702                         sgsize = roundup2(sgsize, dmat->common.alignment);
 703                         sgsize = MIN(sgsize, max_sgsize);
 704                         curaddr = add_bounce_page(dmat, map, vaddr, curaddr,
 705                             sgsize);
 706                 } else {
 707                         sgsize = MIN(sgsize, max_sgsize);
 708                 }
 709                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 710                     segp);
 711                 if (sgsize == 0)
 712                         break;
 713                 vaddr += sgsize;
 714                 buflen -= sgsize;
 715         }
 716
 717         /*
 718          * Did we fit?
 719          */
 720         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 721 }
 722
 723 static void
 724 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 725     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 726 {
 727
 728         if (map == NULL)
 729                 return;
 730         map->mem = *mem;
 731         map->dmat = dmat;
 732         map->callback = callback;
 733         map->callback_arg = callback_arg;
 734 }
 735
 736 static bus_dma_segment_t *
 737 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 738     bus_dma_segment_t *segs, int nsegs, int error)
 739 {
 740
 741         if (segs == NULL)
 742                 segs = dmat->segments;
 743         return (segs);
 744 }
 745
 746 /*
 747  * Release the mapping held by map.
 748  */
 749 static void
 750 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 751 {
 752         struct bounce_page *bpage;
 753
 754         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 755                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 756                 free_bounce_page(dmat, bpage);
 757         }
 758 }
 759
 760 static void
 761 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 762     bus_dmasync_op_t op)
 763 {
 764         struct bounce_page *bpage;
 765
 766         if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 767                 /*
 768                  * Handle data bouncing.  We might also
 769                  * want to add support for invalidating
 770                  * the caches on broken hardware
 771                  */
 772                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 773                     "performing bounce", __func__, dmat,
 774                     dmat->common.flags, op);
 775
 776                 if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 777                         while (bpage != NULL) {
 778                                 if (bpage->datavaddr != 0) {
 779                                         bcopy((void *)bpage->datavaddr,
 780                                             (void *)bpage->vaddr,
 781                                             bpage->datacount);
 782                                 } else {
 783                                         physcopyout(bpage->dataaddr,
 784                                             (void *)bpage->vaddr,
 785                                             bpage->datacount);
 786                                 }
 787                                 bpage = STAILQ_NEXT(bpage, links);
 788                         }
 789                         dmat->bounce_zone->total_bounced++;
 790                 }
 791
 792                 if ((op & BUS_DMASYNC_POSTREAD) != 0) {
 793                         while (bpage != NULL) {
 794                                 if (bpage->datavaddr != 0) {
 795                                         bcopy((void *)bpage->vaddr,
 796                                             (void *)bpage->datavaddr,
 797                                             bpage->datacount);
 798                                 } else {
 799                                         physcopyin((void *)bpage->vaddr,
 800                                             bpage->dataaddr,
 801                                             bpage->datacount);
 802                                 }
 803                                 bpage = STAILQ_NEXT(bpage, links);
 804                         }
 805                         dmat->bounce_zone->total_bounced++;
 806                 }
 807         }
 808 }
 809
 810 static void
 811 init_bounce_pages(void *dummy __unused)
 812 {
 813
 814         total_bpages = 0;
 815         STAILQ_INIT(&bounce_zone_list);
 816         STAILQ_INIT(&bounce_map_waitinglist);
 817         STAILQ_INIT(&bounce_map_callbacklist);
 818         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
 819 }
 820 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
 821
 822 static struct sysctl_ctx_list *
 823 busdma_sysctl_tree(struct bounce_zone *bz)
 824 {
 825         return (&bz->sysctl_tree);
 826 }
 827
 828 static struct sysctl_oid *
 829 busdma_sysctl_tree_top(struct bounce_zone *bz)
 830 {
 831         return (bz->sysctl_tree_top);
 832 }
 833
 834 static int
 835 alloc_bounce_zone(bus_dma_tag_t dmat)
 836 {
 837         struct bounce_zone *bz;
 838
 839         /* Check to see if we already have a suitable zone */
 840         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
 841                 if ((dmat->common.alignment <= bz->alignment) &&
 842                     (dmat->common.lowaddr >= bz->lowaddr)) {
 843                         dmat->bounce_zone = bz;
 844                         return (0);
 845                 }
 846         }
 847
 848         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
 849             M_NOWAIT | M_ZERO)) == NULL)
 850                 return (ENOMEM);
 851
 852         STAILQ_INIT(&bz->bounce_page_list);
 853         bz->free_bpages = 0;
 854         bz->reserved_bpages = 0;
 855         bz->active_bpages = 0;
 856         bz->lowaddr = dmat->common.lowaddr;
 857         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
 858         bz->map_count = 0;
 859         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
 860         busdma_zonecount++;
 861         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
 862         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
 863         dmat->bounce_zone = bz;
 864
 865         sysctl_ctx_init(&bz->sysctl_tree);
 866         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
 867             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
 868             CTLFLAG_RD, 0, "");
 869         if (bz->sysctl_tree_top == NULL) {
 870                 sysctl_ctx_free(&bz->sysctl_tree);
 871                 return (0);     /* XXX error code? */
 872         }
 873
 874         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 875             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 876             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
 877             "Total bounce pages");
 878         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 879             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 880             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
 881             "Free bounce pages");
 882         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 883             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 884             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
 885             "Reserved bounce pages");
 886         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 887             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 888             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
 889             "Active bounce pages");
 890         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 891             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 892             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
 893             "Total bounce requests");
 894         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 895             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 896             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
 897             "Total bounce requests that were deferred");
 898         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
 899             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 900             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
 901         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
 902             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 903             "alignment", CTLFLAG_RD, &bz->alignment, "");
 904
 905         return (0);
 906 }
 907
 908 static int
 909 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 910 {
 911         struct bounce_zone *bz;
 912         int count;
 913
 914         bz = dmat->bounce_zone;
 915         count = 0;
 916         while (numpages > 0) {
 917                 struct bounce_page *bpage;
 918
 919                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
 920                                                      M_NOWAIT | M_ZERO);
 921
 922                 if (bpage == NULL)
 923                         break;
 924                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 925                                                          M_NOWAIT, 0ul,
 926                                                          bz->lowaddr,
 927                                                          PAGE_SIZE,
 928                                                          0);
 929                 if (bpage->vaddr == 0) {
 930                         free(bpage, M_DEVBUF);
 931                         break;
 932                 }
 933                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 934                 mtx_lock(&bounce_lock);
 935                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
 936                 total_bpages++;
 937                 bz->total_bpages++;
 938                 bz->free_bpages++;
 939                 mtx_unlock(&bounce_lock);
 940                 count++;
 941                 numpages--;
 942         }
 943         return (count);
 944 }
 945
 946 static int
 947 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
 948 {
 949         struct bounce_zone *bz;
 950         int pages;
 951
 952         mtx_assert(&bounce_lock, MA_OWNED);
 953         bz = dmat->bounce_zone;
 954         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
 955         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
 956                 return (map->pagesneeded - (map->pagesreserved + pages));
 957         bz->free_bpages -= pages;
 958         bz->reserved_bpages += pages;
 959         map->pagesreserved += pages;
 960         pages = map->pagesneeded - map->pagesreserved;
 961
 962         return (pages);
 963 }
 964
 965 static bus_addr_t
 966 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 967                 bus_addr_t addr, bus_size_t size)
 968 {
 969         struct bounce_zone *bz;
 970         struct bounce_page *bpage;
 971
 972         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
 973         KASSERT(map != NULL && map != &nobounce_dmamap,
 974             ("add_bounce_page: bad map %p", map));
 975
 976         bz = dmat->bounce_zone;
 977         if (map->pagesneeded == 0)
 978                 panic("add_bounce_page: map doesn't need any pages");
 979         map->pagesneeded--;
 980
 981         if (map->pagesreserved == 0)
 982                 panic("add_bounce_page: map doesn't need any pages");
 983         map->pagesreserved--;
 984
 985         mtx_lock(&bounce_lock);
 986         bpage = STAILQ_FIRST(&bz->bounce_page_list);
 987         if (bpage == NULL)
 988                 panic("add_bounce_page: free page list is empty");
 989
 990         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
 991         bz->reserved_bpages--;
 992         bz->active_bpages++;
 993         mtx_unlock(&bounce_lock);
 994
 995         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
 996                 /* Page offset needs to be preserved. */
 997                 bpage->vaddr |= addr & PAGE_MASK;
 998                 bpage->busaddr |= addr & PAGE_MASK;
 999         }
1000         bpage->datavaddr = vaddr;
1001         bpage->dataaddr = addr;
1002         bpage->datacount = size;
1003         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1004         return (bpage->busaddr);
1005 }
1006
1007 static void
1008 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1009 {
1010         struct bus_dmamap *map;
1011         struct bounce_zone *bz;
1012
1013         bz = dmat->bounce_zone;
1014         bpage->datavaddr = 0;
1015         bpage->datacount = 0;
1016         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1017                 /*
1018                  * Reset the bounce page to start at offset 0.  Other uses
1019                  * of this bounce page may need to store a full page of
1020                  * data and/or assume it starts on a page boundary.
1021                  */
1022                 bpage->vaddr &= ~PAGE_MASK;
1023                 bpage->busaddr &= ~PAGE_MASK;
1024         }
1025
1026         mtx_lock(&bounce_lock);
1027         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1028         bz->free_bpages++;
1029         bz->active_bpages--;
1030         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1031                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1032                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1033                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1034                             map, links);
1035                         busdma_swi_pending = 1;
1036                         bz->total_deferred++;
1037                         swi_sched(vm_ih, 0);
1038                 }
1039         }
1040         mtx_unlock(&bounce_lock);
1041 }
1042
1043 void
1044 busdma_swi(void)
1045 {
1046         bus_dma_tag_t dmat;
1047         struct bus_dmamap *map;
1048
1049         mtx_lock(&bounce_lock);
1050         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1051                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1052                 mtx_unlock(&bounce_lock);
1053                 dmat = map->dmat;
1054                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1055                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1056                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1057                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1058                     BUS_DMA_UNLOCK);
1059                 mtx_lock(&bounce_lock);
1060         }
1061         mtx_unlock(&bounce_lock);
1062 }
1063
1064 struct bus_dma_impl bus_dma_bounce_impl = {
1065         .tag_create = bounce_bus_dma_tag_create,
1066         .tag_destroy = bounce_bus_dma_tag_destroy,
1067         .map_create = bounce_bus_dmamap_create,
1068         .map_destroy = bounce_bus_dmamap_destroy,
1069         .mem_alloc = bounce_bus_dmamem_alloc,
1070         .mem_free = bounce_bus_dmamem_free,
1071         .load_phys = bounce_bus_dmamap_load_phys,
1072         .load_buffer = bounce_bus_dmamap_load_buffer,
1073         .load_ma = bus_dmamap_load_ma_triv,
1074         .map_waitok = bounce_bus_dmamap_waitok,
1075         .map_complete = bounce_bus_dmamap_complete,
1076         .map_unload = bounce_bus_dmamap_unload,
1077         .map_sync = bounce_bus_dmamap_sync
1078 };