sys/arm64/arm64/busdma_bounce.c

   1 /*-
   2  * Copyright (c) 1997, 1998 Justin T. Gibbs.
   3  * Copyright (c) 2015 The FreeBSD Foundation
   4  * All rights reserved.
   5  *
   6  * Portions of this software were developed by Semihalf
   7  * under sponsorship of the FreeBSD Foundation.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions, and the following disclaimer,
  14  *    without modification, immediately at the beginning of the file.
  15  * 2. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/malloc.h>
  37 #include <sys/bus.h>
  38 #include <sys/interrupt.h>
  39 #include <sys/kernel.h>
  40 #include <sys/ktr.h>
  41 #include <sys/lock.h>
  42 #include <sys/proc.h>
  43 #include <sys/memdesc.h>
  44 #include <sys/mutex.h>
  45 #include <sys/sysctl.h>
  46 #include <sys/uio.h>
  47
  48 #include <vm/vm.h>
  49 #include <vm/vm_extern.h>
  50 #include <vm/vm_kern.h>
  51 #include <vm/vm_page.h>
  52 #include <vm/vm_map.h>
  53
  54 #include <machine/atomic.h>
  55 #include <machine/bus.h>
  56 #include <machine/md_var.h>
  57 #include <arm64/include/bus_dma_impl.h>
  58
  59 #define MAX_BPAGES 4096
  60
  61 enum {
  62         BUS_DMA_COULD_BOUNCE    = 0x01,
  63         BUS_DMA_MIN_ALLOC_COMP  = 0x02,
  64         BUS_DMA_KMEM_ALLOC      = 0x04,
  65 };
  66
  67 struct bounce_zone;
  68
  69 struct bus_dma_tag {
  70         struct bus_dma_tag_common common;
  71         int                     map_count;
  72         int                     bounce_flags;
  73         bus_dma_segment_t       *segments;
  74         struct bounce_zone      *bounce_zone;
  75 };
  76
  77 struct bounce_page {
  78         vm_offset_t     vaddr;          /* kva of bounce buffer */
  79         bus_addr_t      busaddr;        /* Physical address */
  80         vm_offset_t     datavaddr;      /* kva of client data */
  81         vm_page_t       datapage;       /* physical page of client data */
  82         vm_offset_t     dataoffs;       /* page offset of client data */
  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, bus_size_t size);
 138 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 139 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 140 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 141     pmap_t pmap, void *buf, bus_size_t buflen, int flags);
 142 static void _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
 143     vm_paddr_t buf, bus_size_t buflen, int flags);
 144 static int _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
 145     int flags);
 146
 147 /*
 148  * Allocate a device specific dma_tag.
 149  */
 150 static int
 151 bounce_bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
 152     bus_addr_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
 153     bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
 154     int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
 155     void *lockfuncarg, bus_dma_tag_t *dmat)
 156 {
 157         bus_dma_tag_t newtag;
 158         int error;
 159
 160         *dmat = NULL;
 161         error = common_bus_dma_tag_create(parent != NULL ? &parent->common :
 162             NULL, alignment, boundary, lowaddr, highaddr, filter, filterarg,
 163             maxsize, nsegments, maxsegsz, flags, lockfunc, lockfuncarg,
 164             sizeof (struct bus_dma_tag), (void **)&newtag);
 165         if (error != 0)
 166                 return (error);
 167
 168         newtag->common.impl = &bus_dma_bounce_impl;
 169         newtag->map_count = 0;
 170         newtag->segments = NULL;
 171
 172         if (parent != NULL && ((newtag->common.filter != NULL) ||
 173             ((parent->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0)))
 174                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 175
 176         if (newtag->common.lowaddr < ptoa((vm_paddr_t)Maxmem) ||
 177             newtag->common.alignment > 1)
 178                 newtag->bounce_flags |= BUS_DMA_COULD_BOUNCE;
 179
 180         if (((newtag->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 181             (flags & BUS_DMA_ALLOCNOW) != 0) {
 182                 struct bounce_zone *bz;
 183
 184                 /* Must bounce */
 185                 if ((error = alloc_bounce_zone(newtag)) != 0) {
 186                         free(newtag, M_DEVBUF);
 187                         return (error);
 188                 }
 189                 bz = newtag->bounce_zone;
 190
 191                 if (ptoa(bz->total_bpages) < maxsize) {
 192                         int pages;
 193
 194                         pages = atop(maxsize) - bz->total_bpages;
 195
 196                         /* Add pages to our bounce pool */
 197                         if (alloc_bounce_pages(newtag, pages) < pages)
 198                                 error = ENOMEM;
 199                 }
 200                 /* Performed initial allocation */
 201                 newtag->bounce_flags |= BUS_DMA_MIN_ALLOC_COMP;
 202         } else
 203                 error = 0;
 204
 205         if (error != 0)
 206                 free(newtag, M_DEVBUF);
 207         else
 208                 *dmat = newtag;
 209         CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
 210             __func__, newtag, (newtag != NULL ? newtag->common.flags : 0),
 211             error);
 212         return (error);
 213 }
 214
 215 static int
 216 bounce_bus_dma_tag_destroy(bus_dma_tag_t dmat)
 217 {
 218         bus_dma_tag_t dmat_copy, parent;
 219         int error;
 220
 221         error = 0;
 222         dmat_copy = dmat;
 223
 224         if (dmat != NULL) {
 225                 if (dmat->map_count != 0) {
 226                         error = EBUSY;
 227                         goto out;
 228                 }
 229                 while (dmat != NULL) {
 230                         parent = (bus_dma_tag_t)dmat->common.parent;
 231                         atomic_subtract_int(&dmat->common.ref_count, 1);
 232                         if (dmat->common.ref_count == 0) {
 233                                 if (dmat->segments != NULL)
 234                                         free(dmat->segments, M_DEVBUF);
 235                                 free(dmat, M_DEVBUF);
 236                                 /*
 237                                  * Last reference count, so
 238                                  * release our reference
 239                                  * count on our parent.
 240                                  */
 241                                 dmat = parent;
 242                         } else
 243                                 dmat = NULL;
 244                 }
 245         }
 246 out:
 247         CTR3(KTR_BUSDMA, "%s tag %p error %d", __func__, dmat_copy, error);
 248         return (error);
 249 }
 250
 251 /*
 252  * Allocate a handle for mapping from kva/uva/physical
 253  * address space into bus device space.
 254  */
 255 static int
 256 bounce_bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
 257 {
 258         struct bounce_zone *bz;
 259         int error, maxpages, pages;
 260
 261         error = 0;
 262
 263         if (dmat->segments == NULL) {
 264                 dmat->segments = (bus_dma_segment_t *)malloc(
 265                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 266                     M_DEVBUF, M_NOWAIT);
 267                 if (dmat->segments == NULL) {
 268                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 269                             __func__, dmat, ENOMEM);
 270                         return (ENOMEM);
 271                 }
 272         }
 273
 274         /*
 275          * Bouncing might be required if the driver asks for an active
 276          * exclusion region, a data alignment that is stricter than 1, and/or
 277          * an active address boundary.
 278          */
 279         if (dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) {
 280                 /* Must bounce */
 281                 if (dmat->bounce_zone == NULL) {
 282                         if ((error = alloc_bounce_zone(dmat)) != 0)
 283                                 return (error);
 284                 }
 285                 bz = dmat->bounce_zone;
 286
 287                 *mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
 288                     M_NOWAIT | M_ZERO);
 289                 if (*mapp == NULL) {
 290                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 291                             __func__, dmat, ENOMEM);
 292                         return (ENOMEM);
 293                 }
 294
 295                 /* Initialize the new map */
 296                 STAILQ_INIT(&((*mapp)->bpages));
 297
 298                 /*
 299                  * Attempt to add pages to our pool on a per-instance
 300                  * basis up to a sane limit.
 301                  */
 302                 if (dmat->common.alignment > 1)
 303                         maxpages = MAX_BPAGES;
 304                 else
 305                         maxpages = MIN(MAX_BPAGES, Maxmem -
 306                             atop(dmat->common.lowaddr));
 307                 if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP) == 0 ||
 308                     (bz->map_count > 0 && bz->total_bpages < maxpages)) {
 309                         pages = MAX(atop(dmat->common.maxsize), 1);
 310                         pages = MIN(maxpages - bz->total_bpages, pages);
 311                         pages = MAX(pages, 1);
 312                         if (alloc_bounce_pages(dmat, pages) < pages)
 313                                 error = ENOMEM;
 314                         if ((dmat->bounce_flags & BUS_DMA_MIN_ALLOC_COMP)
 315                             == 0) {
 316                                 if (error == 0) {
 317                                         dmat->bounce_flags |=
 318                                             BUS_DMA_MIN_ALLOC_COMP;
 319                                 }
 320                         } else
 321                                 error = 0;
 322                 }
 323                 bz->map_count++;
 324         } else {
 325                 *mapp = NULL;
 326         }
 327         if (error == 0)
 328                 dmat->map_count++;
 329         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 330             __func__, dmat, dmat->common.flags, error);
 331         return (error);
 332 }
 333
 334 /*
 335  * Destroy a handle for mapping from kva/uva/physical
 336  * address space into bus device space.
 337  */
 338 static int
 339 bounce_bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
 340 {
 341
 342         if (map != NULL && map != &nobounce_dmamap) {
 343                 if (STAILQ_FIRST(&map->bpages) != NULL) {
 344                         CTR3(KTR_BUSDMA, "%s: tag %p error %d",
 345                             __func__, dmat, EBUSY);
 346                         return (EBUSY);
 347                 }
 348                 if (dmat->bounce_zone)
 349                         dmat->bounce_zone->map_count--;
 350                 free(map, M_DEVBUF);
 351         }
 352         dmat->map_count--;
 353         CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
 354         return (0);
 355 }
 356
 357
 358 /*
 359  * Allocate a piece of memory that can be efficiently mapped into
 360  * bus device space based on the constraints lited in the dma tag.
 361  * A dmamap to for use with dmamap_load is also allocated.
 362  */
 363 static int
 364 bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
 365     bus_dmamap_t *mapp)
 366 {
 367         /*
 368          * XXX ARM64TODO:
 369          * This bus_dma implementation requires IO-Coherent architecutre.
 370          * If IO-Coherency is not guaranteed, the BUS_DMA_COHERENT flag has
 371          * to be implented using non-cacheable memory.
 372          */
 373
 374         vm_memattr_t attr;
 375         int mflags;
 376
 377         if (flags & BUS_DMA_NOWAIT)
 378                 mflags = M_NOWAIT;
 379         else
 380                 mflags = M_WAITOK;
 381
 382         /* If we succeed, no mapping/bouncing will be required */
 383         *mapp = NULL;
 384
 385         if (dmat->segments == NULL) {
 386                 dmat->segments = (bus_dma_segment_t *)malloc(
 387                     sizeof(bus_dma_segment_t) * dmat->common.nsegments,
 388                     M_DEVBUF, mflags);
 389                 if (dmat->segments == NULL) {
 390                         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 391                             __func__, dmat, dmat->common.flags, ENOMEM);
 392                         return (ENOMEM);
 393                 }
 394         }
 395         if (flags & BUS_DMA_ZERO)
 396                 mflags |= M_ZERO;
 397         if (flags & BUS_DMA_NOCACHE)
 398                 attr = VM_MEMATTR_UNCACHEABLE;
 399         else
 400                 attr = VM_MEMATTR_DEFAULT;
 401
 402         /*
 403          * XXX:
 404          * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
 405          * alignment guarantees of malloc need to be nailed down, and the
 406          * code below should be rewritten to take that into account.
 407          *
 408          * In the meantime, we'll warn the user if malloc gets it wrong.
 409          */
 410         if ((dmat->common.maxsize <= PAGE_SIZE) &&
 411            (dmat->common.alignment < dmat->common.maxsize) &&
 412             dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
 413             attr == VM_MEMATTR_DEFAULT) {
 414                 *vaddr = malloc(dmat->common.maxsize, M_DEVBUF, mflags);
 415         } else if (dmat->common.nsegments >= btoc(dmat->common.maxsize) &&
 416             dmat->common.alignment <= PAGE_SIZE &&
 417             (dmat->common.boundary == 0 ||
 418             dmat->common.boundary >= dmat->common.lowaddr)) {
 419                 /* Page-based multi-segment allocations allowed */
 420                 *vaddr = (void *)kmem_alloc_attr(kernel_arena,
 421                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 422                     attr);
 423                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 424         } else {
 425                 *vaddr = (void *)kmem_alloc_contig(kernel_arena,
 426                     dmat->common.maxsize, mflags, 0ul, dmat->common.lowaddr,
 427                     dmat->common.alignment != 0 ? dmat->common.alignment : 1ul,
 428                     dmat->common.boundary, attr);
 429                 dmat->bounce_flags |= BUS_DMA_KMEM_ALLOC;
 430         }
 431         if (*vaddr == NULL) {
 432                 CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 433                     __func__, dmat, dmat->common.flags, ENOMEM);
 434                 return (ENOMEM);
 435         } else if (vtophys(*vaddr) & (dmat->common.alignment - 1)) {
 436                 printf("bus_dmamem_alloc failed to align memory properly.\n");
 437         }
 438         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
 439             __func__, dmat, dmat->common.flags, 0);
 440         return (0);
 441 }
 442
 443 /*
 444  * Free a piece of memory and it's allociated dmamap, that was allocated
 445  * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
 446  */
 447 static void
 448 bounce_bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
 449 {
 450         /*
 451          * dmamem does not need to be bounced, so the map should be
 452          * NULL and the BUS_DMA_KMEM_ALLOC flag cleared if malloc()
 453          * was used and set if kmem_alloc_contig() was used.
 454          */
 455         if (map != NULL)
 456                 panic("bus_dmamem_free: Invalid map freed\n");
 457         if ((dmat->bounce_flags & BUS_DMA_KMEM_ALLOC) == 0)
 458                 free(vaddr, M_DEVBUF);
 459         else
 460                 kmem_free(kernel_arena, (vm_offset_t)vaddr,
 461                     dmat->common.maxsize);
 462         CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat,
 463             dmat->bounce_flags);
 464 }
 465
 466 static void
 467 _bus_dmamap_count_phys(bus_dma_tag_t dmat, bus_dmamap_t map, vm_paddr_t buf,
 468     bus_size_t buflen, int flags)
 469 {
 470         bus_addr_t curaddr;
 471         bus_size_t sgsize;
 472
 473         if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
 474                 /*
 475                  * Count the number of bounce pages
 476                  * needed in order to complete this transfer
 477                  */
 478                 curaddr = buf;
 479                 while (buflen != 0) {
 480                         sgsize = MIN(buflen, dmat->common.maxsegsz);
 481                         if (bus_dma_run_filter(&dmat->common, curaddr)) {
 482                                 sgsize = MIN(sgsize,
 483                                     PAGE_SIZE - (curaddr & PAGE_MASK));
 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 - (curaddr & PAGE_MASK));
 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 kvaddr, 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                         kvaddr = vaddr;
 692                 } else {
 693                         curaddr = pmap_extract(pmap, vaddr);
 694                         kvaddr = 0;
 695                 }
 696
 697                 /*
 698                  * Compute the segment size, and adjust counts.
 699                  */
 700                 max_sgsize = MIN(buflen, dmat->common.maxsegsz);
 701                 sgsize = PAGE_SIZE - (curaddr & PAGE_MASK);
 702                 if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
 703                     map->pagesneeded != 0 &&
 704                     bus_dma_run_filter(&dmat->common, curaddr)) {
 705                         sgsize = roundup2(sgsize, dmat->common.alignment);
 706                         sgsize = MIN(sgsize, max_sgsize);
 707                         curaddr = add_bounce_page(dmat, map, kvaddr, curaddr,
 708                             sgsize);
 709                 } else {
 710                         sgsize = MIN(sgsize, max_sgsize);
 711                 }
 712                 sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
 713                     segp);
 714                 if (sgsize == 0)
 715                         break;
 716                 vaddr += sgsize;
 717                 buflen -= sgsize;
 718         }
 719
 720         /*
 721          * Did we fit?
 722          */
 723         return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 724 }
 725
 726 static void
 727 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
 728     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
 729 {
 730
 731         if (map == NULL)
 732                 return;
 733         map->mem = *mem;
 734         map->dmat = dmat;
 735         map->callback = callback;
 736         map->callback_arg = callback_arg;
 737 }
 738
 739 static bus_dma_segment_t *
 740 bounce_bus_dmamap_complete(bus_dma_tag_t dmat, bus_dmamap_t map,
 741     bus_dma_segment_t *segs, int nsegs, int error)
 742 {
 743
 744         if (segs == NULL)
 745                 segs = dmat->segments;
 746         return (segs);
 747 }
 748
 749 /*
 750  * Release the mapping held by map.
 751  */
 752 static void
 753 bounce_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
 754 {
 755         struct bounce_page *bpage;
 756
 757         while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
 758                 STAILQ_REMOVE_HEAD(&map->bpages, links);
 759                 free_bounce_page(dmat, bpage);
 760         }
 761 }
 762
 763 static void
 764 bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 765     bus_dmasync_op_t op)
 766 {
 767         struct bounce_page *bpage;
 768         vm_offset_t datavaddr, tempvaddr;
 769
 770         if ((bpage = STAILQ_FIRST(&map->bpages)) == NULL)
 771                 return;
 772
 773         /*
 774          * XXX ARM64TODO:
 775          * This bus_dma implementation requires IO-Coherent architecutre.
 776          * If IO-Coherency is not guaranteed, cache operations have to be
 777          * added to this function.
 778          */
 779
 780         CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x "
 781             "performing bounce", __func__, dmat, dmat->common.flags, op);
 782
 783         if ((op & BUS_DMASYNC_PREWRITE) != 0) {
 784                 while (bpage != NULL) {
 785                         tempvaddr = 0;
 786                         datavaddr = bpage->datavaddr;
 787                         if (datavaddr == 0) {
 788                                 tempvaddr =
 789                                     pmap_quick_enter_page(bpage->datapage);
 790                                 datavaddr = tempvaddr | bpage->dataoffs;
 791                         }
 792
 793                         bcopy((void *)datavaddr,
 794                             (void *)bpage->vaddr, bpage->datacount);
 795
 796                         if (tempvaddr != 0)
 797                                 pmap_quick_remove_page(tempvaddr);
 798                         bpage = STAILQ_NEXT(bpage, links);
 799                 }
 800                 dmat->bounce_zone->total_bounced++;
 801         }
 802
 803         if ((op & BUS_DMASYNC_POSTREAD) != 0) {
 804                 while (bpage != NULL) {
 805                         tempvaddr = 0;
 806                         datavaddr = bpage->datavaddr;
 807                         if (datavaddr == 0) {
 808                                 tempvaddr =
 809                                     pmap_quick_enter_page(bpage->datapage);
 810                                 datavaddr = tempvaddr | bpage->dataoffs;
 811                         }
 812
 813                         bcopy((void *)bpage->vaddr,
 814                             (void *)datavaddr, bpage->datacount);
 815
 816                         if (tempvaddr != 0)
 817                                 pmap_quick_remove_page(tempvaddr);
 818                         bpage = STAILQ_NEXT(bpage, links);
 819                 }
 820                 dmat->bounce_zone->total_bounced++;
 821         }
 822 }
 823
 824 static void
 825 init_bounce_pages(void *dummy __unused)
 826 {
 827
 828         total_bpages = 0;
 829         STAILQ_INIT(&bounce_zone_list);
 830         STAILQ_INIT(&bounce_map_waitinglist);
 831         STAILQ_INIT(&bounce_map_callbacklist);
 832         mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
 833 }
 834 SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
 835
 836 static struct sysctl_ctx_list *
 837 busdma_sysctl_tree(struct bounce_zone *bz)
 838 {
 839         return (&bz->sysctl_tree);
 840 }
 841
 842 static struct sysctl_oid *
 843 busdma_sysctl_tree_top(struct bounce_zone *bz)
 844 {
 845         return (bz->sysctl_tree_top);
 846 }
 847
 848 static int
 849 alloc_bounce_zone(bus_dma_tag_t dmat)
 850 {
 851         struct bounce_zone *bz;
 852
 853         /* Check to see if we already have a suitable zone */
 854         STAILQ_FOREACH(bz, &bounce_zone_list, links) {
 855                 if ((dmat->common.alignment <= bz->alignment) &&
 856                     (dmat->common.lowaddr >= bz->lowaddr)) {
 857                         dmat->bounce_zone = bz;
 858                         return (0);
 859                 }
 860         }
 861
 862         if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
 863             M_NOWAIT | M_ZERO)) == NULL)
 864                 return (ENOMEM);
 865
 866         STAILQ_INIT(&bz->bounce_page_list);
 867         bz->free_bpages = 0;
 868         bz->reserved_bpages = 0;
 869         bz->active_bpages = 0;
 870         bz->lowaddr = dmat->common.lowaddr;
 871         bz->alignment = MAX(dmat->common.alignment, PAGE_SIZE);
 872         bz->map_count = 0;
 873         snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
 874         busdma_zonecount++;
 875         snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
 876         STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
 877         dmat->bounce_zone = bz;
 878
 879         sysctl_ctx_init(&bz->sysctl_tree);
 880         bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
 881             SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
 882             CTLFLAG_RD, 0, "");
 883         if (bz->sysctl_tree_top == NULL) {
 884                 sysctl_ctx_free(&bz->sysctl_tree);
 885                 return (0);     /* XXX error code? */
 886         }
 887
 888         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 889             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 890             "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
 891             "Total bounce pages");
 892         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 893             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 894             "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
 895             "Free bounce pages");
 896         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 897             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 898             "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
 899             "Reserved bounce pages");
 900         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 901             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 902             "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
 903             "Active bounce pages");
 904         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 905             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 906             "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
 907             "Total bounce requests");
 908         SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
 909             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 910             "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
 911             "Total bounce requests that were deferred");
 912         SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
 913             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 914             "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
 915         SYSCTL_ADD_UAUTO(busdma_sysctl_tree(bz),
 916             SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
 917             "alignment", CTLFLAG_RD, &bz->alignment, "");
 918
 919         return (0);
 920 }
 921
 922 static int
 923 alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
 924 {
 925         struct bounce_zone *bz;
 926         int count;
 927
 928         bz = dmat->bounce_zone;
 929         count = 0;
 930         while (numpages > 0) {
 931                 struct bounce_page *bpage;
 932
 933                 bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
 934                                                      M_NOWAIT | M_ZERO);
 935
 936                 if (bpage == NULL)
 937                         break;
 938                 bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
 939                     M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
 940                 if (bpage->vaddr == 0) {
 941                         free(bpage, M_DEVBUF);
 942                         break;
 943                 }
 944                 bpage->busaddr = pmap_kextract(bpage->vaddr);
 945                 mtx_lock(&bounce_lock);
 946                 STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
 947                 total_bpages++;
 948                 bz->total_bpages++;
 949                 bz->free_bpages++;
 950                 mtx_unlock(&bounce_lock);
 951                 count++;
 952                 numpages--;
 953         }
 954         return (count);
 955 }
 956
 957 static int
 958 reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
 959 {
 960         struct bounce_zone *bz;
 961         int pages;
 962
 963         mtx_assert(&bounce_lock, MA_OWNED);
 964         bz = dmat->bounce_zone;
 965         pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
 966         if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
 967                 return (map->pagesneeded - (map->pagesreserved + pages));
 968         bz->free_bpages -= pages;
 969         bz->reserved_bpages += pages;
 970         map->pagesreserved += pages;
 971         pages = map->pagesneeded - map->pagesreserved;
 972
 973         return (pages);
 974 }
 975
 976 static bus_addr_t
 977 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 978                 bus_addr_t addr, bus_size_t size)
 979 {
 980         struct bounce_zone *bz;
 981         struct bounce_page *bpage;
 982
 983         KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
 984         KASSERT(map != NULL && map != &nobounce_dmamap,
 985             ("add_bounce_page: bad map %p", map));
 986
 987         bz = dmat->bounce_zone;
 988         if (map->pagesneeded == 0)
 989                 panic("add_bounce_page: map doesn't need any pages");
 990         map->pagesneeded--;
 991
 992         if (map->pagesreserved == 0)
 993                 panic("add_bounce_page: map doesn't need any pages");
 994         map->pagesreserved--;
 995
 996         mtx_lock(&bounce_lock);
 997         bpage = STAILQ_FIRST(&bz->bounce_page_list);
 998         if (bpage == NULL)
 999                 panic("add_bounce_page: free page list is empty");
1000
1001         STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1002         bz->reserved_bpages--;
1003         bz->active_bpages++;
1004         mtx_unlock(&bounce_lock);
1005
1006         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1007                 /* Page offset needs to be preserved. */
1008                 bpage->vaddr |= addr & PAGE_MASK;
1009                 bpage->busaddr |= addr & PAGE_MASK;
1010         }
1011         bpage->datavaddr = vaddr;
1012         bpage->datapage = PHYS_TO_VM_PAGE(addr);
1013         bpage->dataoffs = addr & PAGE_MASK;
1014         bpage->datacount = size;
1015         STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1016         return (bpage->busaddr);
1017 }
1018
1019 static void
1020 free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1021 {
1022         struct bus_dmamap *map;
1023         struct bounce_zone *bz;
1024
1025         bz = dmat->bounce_zone;
1026         bpage->datavaddr = 0;
1027         bpage->datacount = 0;
1028         if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
1029                 /*
1030                  * Reset the bounce page to start at offset 0.  Other uses
1031                  * of this bounce page may need to store a full page of
1032                  * data and/or assume it starts on a page boundary.
1033                  */
1034                 bpage->vaddr &= ~PAGE_MASK;
1035                 bpage->busaddr &= ~PAGE_MASK;
1036         }
1037
1038         mtx_lock(&bounce_lock);
1039         STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1040         bz->free_bpages++;
1041         bz->active_bpages--;
1042         if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1043                 if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1044                         STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1045                         STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1046                             map, links);
1047                         busdma_swi_pending = 1;
1048                         bz->total_deferred++;
1049                         swi_sched(vm_ih, 0);
1050                 }
1051         }
1052         mtx_unlock(&bounce_lock);
1053 }
1054
1055 void
1056 busdma_swi(void)
1057 {
1058         bus_dma_tag_t dmat;
1059         struct bus_dmamap *map;
1060
1061         mtx_lock(&bounce_lock);
1062         while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1063                 STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1064                 mtx_unlock(&bounce_lock);
1065                 dmat = map->dmat;
1066                 (dmat->common.lockfunc)(dmat->common.lockfuncarg, BUS_DMA_LOCK);
1067                 bus_dmamap_load_mem(map->dmat, map, &map->mem,
1068                     map->callback, map->callback_arg, BUS_DMA_WAITOK);
1069                 (dmat->common.lockfunc)(dmat->common.lockfuncarg,
1070                     BUS_DMA_UNLOCK);
1071                 mtx_lock(&bounce_lock);
1072         }
1073         mtx_unlock(&bounce_lock);
1074 }
1075
1076 struct bus_dma_impl bus_dma_bounce_impl = {
1077         .tag_create = bounce_bus_dma_tag_create,
1078         .tag_destroy = bounce_bus_dma_tag_destroy,
1079         .map_create = bounce_bus_dmamap_create,
1080         .map_destroy = bounce_bus_dmamap_destroy,
1081         .mem_alloc = bounce_bus_dmamem_alloc,
1082         .mem_free = bounce_bus_dmamem_free,
1083         .load_phys = bounce_bus_dmamap_load_phys,
1084         .load_buffer = bounce_bus_dmamap_load_buffer,
1085         .load_ma = bus_dmamap_load_ma_triv,
1086         .map_waitok = bounce_bus_dmamap_waitok,
1087         .map_complete = bounce_bus_dmamap_complete,
1088         .map_unload = bounce_bus_dmamap_unload,
1089         .map_sync = bounce_bus_dmamap_sync
1090 };