arch/arm64/mm/dma-mapping.c

   1 /*
   2  * SWIOTLB-based DMA API implementation
   3  *
   4  * Copyright (C) 2012 ARM Ltd.
   5  * Author: Catalin Marinas <catalin.marinas@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/gfp.h>
  21 #include <linux/acpi.h>
  22 #include <linux/bootmem.h>
  23 #include <linux/cache.h>
  24 #include <linux/export.h>
  25 #include <linux/slab.h>
  26 #include <linux/genalloc.h>
  27 #include <linux/dma-mapping.h>
  28 #include <linux/dma-contiguous.h>
  29 #include <linux/vmalloc.h>
  30 #include <linux/swiotlb.h>
  31
  32 #include <asm/cacheflush.h>
  33
  34 static int swiotlb __ro_after_init;
  35
  36 static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot,
  37                                  bool coherent)
  38 {
  39         if (!coherent || (attrs & DMA_ATTR_WRITE_COMBINE))
  40                 return pgprot_writecombine(prot);
  41         return prot;
  42 }
  43
  44 static struct gen_pool *atomic_pool;
  45
  46 #define DEFAULT_DMA_COHERENT_POOL_SIZE  SZ_256K
  47 static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
  48
  49 static int __init early_coherent_pool(char *p)
  50 {
  51         atomic_pool_size = memparse(p, &p);
  52         return 0;
  53 }
  54 early_param("coherent_pool", early_coherent_pool);
  55
  56 static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
  57 {
  58         unsigned long val;
  59         void *ptr = NULL;
  60
  61         if (!atomic_pool) {
  62                 WARN(1, "coherent pool not initialised!\n");
  63                 return NULL;
  64         }
  65
  66         val = gen_pool_alloc(atomic_pool, size);
  67         if (val) {
  68                 phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
  69
  70                 *ret_page = phys_to_page(phys);
  71                 ptr = (void *)val;
  72                 memset(ptr, 0, size);
  73         }
  74
  75         return ptr;
  76 }
  77
  78 static bool __in_atomic_pool(void *start, size_t size)
  79 {
  80         return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
  81 }
  82
  83 static int __free_from_pool(void *start, size_t size)
  84 {
  85         if (!__in_atomic_pool(start, size))
  86                 return 0;
  87
  88         gen_pool_free(atomic_pool, (unsigned long)start, size);
  89
  90         return 1;
  91 }
  92
  93 static void *__dma_alloc_coherent(struct device *dev, size_t size,
  94                                   dma_addr_t *dma_handle, gfp_t flags,
  95                                   unsigned long attrs)
  96 {
  97         if (dev == NULL) {
  98                 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
  99                 return NULL;
 100         }
 101
 102         if (IS_ENABLED(CONFIG_ZONE_DMA) &&
 103             dev->coherent_dma_mask <= DMA_BIT_MASK(32))
 104                 flags |= GFP_DMA;
 105         if (dev_get_cma_area(dev) && gfpflags_allow_blocking(flags)) {
 106                 struct page *page;
 107                 void *addr;
 108
 109                 page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
 110                                                         get_order(size));
 111                 if (!page)
 112                         return NULL;
 113
 114                 *dma_handle = phys_to_dma(dev, page_to_phys(page));
 115                 addr = page_address(page);
 116                 memset(addr, 0, size);
 117                 return addr;
 118         } else {
 119                 return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
 120         }
 121 }
 122
 123 static void __dma_free_coherent(struct device *dev, size_t size,
 124                                 void *vaddr, dma_addr_t dma_handle,
 125                                 unsigned long attrs)
 126 {
 127         bool freed;
 128         phys_addr_t paddr = dma_to_phys(dev, dma_handle);
 129
 130         if (dev == NULL) {
 131                 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
 132                 return;
 133         }
 134
 135         freed = dma_release_from_contiguous(dev,
 136                                         phys_to_page(paddr),
 137                                         size >> PAGE_SHIFT);
 138         if (!freed)
 139                 swiotlb_free_coherent(dev, size, vaddr, dma_handle);
 140 }
 141
 142 static void *__dma_alloc(struct device *dev, size_t size,
 143                          dma_addr_t *dma_handle, gfp_t flags,
 144                          unsigned long attrs)
 145 {
 146         struct page *page;
 147         void *ptr, *coherent_ptr;
 148         bool coherent = is_device_dma_coherent(dev);
 149         pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, false);
 150
 151         size = PAGE_ALIGN(size);
 152
 153         if (!coherent && !gfpflags_allow_blocking(flags)) {
 154                 struct page *page = NULL;
 155                 void *addr = __alloc_from_pool(size, &page, flags);
 156
 157                 if (addr)
 158                         *dma_handle = phys_to_dma(dev, page_to_phys(page));
 159
 160                 return addr;
 161         }
 162
 163         ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
 164         if (!ptr)
 165                 goto no_mem;
 166
 167         /* no need for non-cacheable mapping if coherent */
 168         if (coherent)
 169                 return ptr;
 170
 171         /* remove any dirty cache lines on the kernel alias */
 172         __dma_flush_area(ptr, size);
 173
 174         /* create a coherent mapping */
 175         page = virt_to_page(ptr);
 176         coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
 177                                                    prot, NULL);
 178         if (!coherent_ptr)
 179                 goto no_map;
 180
 181         return coherent_ptr;
 182
 183 no_map:
 184         __dma_free_coherent(dev, size, ptr, *dma_handle, attrs);
 185 no_mem:
 186         *dma_handle = DMA_ERROR_CODE;
 187         return NULL;
 188 }
 189
 190 static void __dma_free(struct device *dev, size_t size,
 191                        void *vaddr, dma_addr_t dma_handle,
 192                        unsigned long attrs)
 193 {
 194         void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
 195
 196         size = PAGE_ALIGN(size);
 197
 198         if (!is_device_dma_coherent(dev)) {
 199                 if (__free_from_pool(vaddr, size))
 200                         return;
 201                 vunmap(vaddr);
 202         }
 203         __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs);
 204 }
 205
 206 static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
 207                                      unsigned long offset, size_t size,
 208                                      enum dma_data_direction dir,
 209                                      unsigned long attrs)
 210 {
 211         dma_addr_t dev_addr;
 212
 213         dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
 214         if (!is_device_dma_coherent(dev))
 215                 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 216
 217         return dev_addr;
 218 }
 219
 220
 221 static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
 222                                  size_t size, enum dma_data_direction dir,
 223                                  unsigned long attrs)
 224 {
 225         if (!is_device_dma_coherent(dev))
 226                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 227         swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
 228 }
 229
 230 static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 231                                   int nelems, enum dma_data_direction dir,
 232                                   unsigned long attrs)
 233 {
 234         struct scatterlist *sg;
 235         int i, ret;
 236
 237         ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
 238         if (!is_device_dma_coherent(dev))
 239                 for_each_sg(sgl, sg, ret, i)
 240                         __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 241                                        sg->length, dir);
 242
 243         return ret;
 244 }
 245
 246 static void __swiotlb_unmap_sg_attrs(struct device *dev,
 247                                      struct scatterlist *sgl, int nelems,
 248                                      enum dma_data_direction dir,
 249                                      unsigned long attrs)
 250 {
 251         struct scatterlist *sg;
 252         int i;
 253
 254         if (!is_device_dma_coherent(dev))
 255                 for_each_sg(sgl, sg, nelems, i)
 256                         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 257                                          sg->length, dir);
 258         swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
 259 }
 260
 261 static void __swiotlb_sync_single_for_cpu(struct device *dev,
 262                                           dma_addr_t dev_addr, size_t size,
 263                                           enum dma_data_direction dir)
 264 {
 265         if (!is_device_dma_coherent(dev))
 266                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 267         swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
 268 }
 269
 270 static void __swiotlb_sync_single_for_device(struct device *dev,
 271                                              dma_addr_t dev_addr, size_t size,
 272                                              enum dma_data_direction dir)
 273 {
 274         swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
 275         if (!is_device_dma_coherent(dev))
 276                 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 277 }
 278
 279 static void __swiotlb_sync_sg_for_cpu(struct device *dev,
 280                                       struct scatterlist *sgl, int nelems,
 281                                       enum dma_data_direction dir)
 282 {
 283         struct scatterlist *sg;
 284         int i;
 285
 286         if (!is_device_dma_coherent(dev))
 287                 for_each_sg(sgl, sg, nelems, i)
 288                         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 289                                          sg->length, dir);
 290         swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
 291 }
 292
 293 static void __swiotlb_sync_sg_for_device(struct device *dev,
 294                                          struct scatterlist *sgl, int nelems,
 295                                          enum dma_data_direction dir)
 296 {
 297         struct scatterlist *sg;
 298         int i;
 299
 300         swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
 301         if (!is_device_dma_coherent(dev))
 302                 for_each_sg(sgl, sg, nelems, i)
 303                         __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 304                                        sg->length, dir);
 305 }
 306
 307 static int __swiotlb_mmap(struct device *dev,
 308                           struct vm_area_struct *vma,
 309                           void *cpu_addr, dma_addr_t dma_addr, size_t size,
 310                           unsigned long attrs)
 311 {
 312         int ret = -ENXIO;
 313         unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
 314                                         PAGE_SHIFT;
 315         unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 316         unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
 317         unsigned long off = vma->vm_pgoff;
 318
 319         vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
 320                                              is_device_dma_coherent(dev));
 321
 322         if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 323                 return ret;
 324
 325         if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
 326                 ret = remap_pfn_range(vma, vma->vm_start,
 327                                       pfn + off,
 328                                       vma->vm_end - vma->vm_start,
 329                                       vma->vm_page_prot);
 330         }
 331
 332         return ret;
 333 }
 334
 335 static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
 336                                  void *cpu_addr, dma_addr_t handle, size_t size,
 337                                  unsigned long attrs)
 338 {
 339         int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 340
 341         if (!ret)
 342                 sg_set_page(sgt->sgl, phys_to_page(dma_to_phys(dev, handle)),
 343                             PAGE_ALIGN(size), 0);
 344
 345         return ret;
 346 }
 347
 348 static int __swiotlb_dma_supported(struct device *hwdev, u64 mask)
 349 {
 350         if (swiotlb)
 351                 return swiotlb_dma_supported(hwdev, mask);
 352         return 1;
 353 }
 354
 355 static struct dma_map_ops swiotlb_dma_ops = {
 356         .alloc = __dma_alloc,
 357         .free = __dma_free,
 358         .mmap = __swiotlb_mmap,
 359         .get_sgtable = __swiotlb_get_sgtable,
 360         .map_page = __swiotlb_map_page,
 361         .unmap_page = __swiotlb_unmap_page,
 362         .map_sg = __swiotlb_map_sg_attrs,
 363         .unmap_sg = __swiotlb_unmap_sg_attrs,
 364         .sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
 365         .sync_single_for_device = __swiotlb_sync_single_for_device,
 366         .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
 367         .sync_sg_for_device = __swiotlb_sync_sg_for_device,
 368         .dma_supported = __swiotlb_dma_supported,
 369         .mapping_error = swiotlb_dma_mapping_error,
 370 };
 371
 372 static int __init atomic_pool_init(void)
 373 {
 374         pgprot_t prot = __pgprot(PROT_NORMAL_NC);
 375         unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
 376         struct page *page;
 377         void *addr;
 378         unsigned int pool_size_order = get_order(atomic_pool_size);
 379
 380         if (dev_get_cma_area(NULL))
 381                 page = dma_alloc_from_contiguous(NULL, nr_pages,
 382                                                         pool_size_order);
 383         else
 384                 page = alloc_pages(GFP_DMA, pool_size_order);
 385
 386         if (page) {
 387                 int ret;
 388                 void *page_addr = page_address(page);
 389
 390                 memset(page_addr, 0, atomic_pool_size);
 391                 __dma_flush_area(page_addr, atomic_pool_size);
 392
 393                 atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
 394                 if (!atomic_pool)
 395                         goto free_page;
 396
 397                 addr = dma_common_contiguous_remap(page, atomic_pool_size,
 398                                         VM_USERMAP, prot, atomic_pool_init);
 399
 400                 if (!addr)
 401                         goto destroy_genpool;
 402
 403                 ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
 404                                         page_to_phys(page),
 405                                         atomic_pool_size, -1);
 406                 if (ret)
 407                         goto remove_mapping;
 408
 409                 gen_pool_set_algo(atomic_pool,
 410                                   gen_pool_first_fit_order_align,
 411                                   (void *)PAGE_SHIFT);
 412
 413                 pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
 414                         atomic_pool_size / 1024);
 415                 return 0;
 416         }
 417         goto out;
 418
 419 remove_mapping:
 420         dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
 421 destroy_genpool:
 422         gen_pool_destroy(atomic_pool);
 423         atomic_pool = NULL;
 424 free_page:
 425         if (!dma_release_from_contiguous(NULL, page, nr_pages))
 426                 __free_pages(page, pool_size_order);
 427 out:
 428         pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
 429                 atomic_pool_size / 1024);
 430         return -ENOMEM;
 431 }
 432
 433 /********************************************
 434  * The following APIs are for dummy DMA ops *
 435  ********************************************/
 436
 437 static void *__dummy_alloc(struct device *dev, size_t size,
 438                            dma_addr_t *dma_handle, gfp_t flags,
 439                            unsigned long attrs)
 440 {
 441         return NULL;
 442 }
 443
 444 static void __dummy_free(struct device *dev, size_t size,
 445                          void *vaddr, dma_addr_t dma_handle,
 446                          unsigned long attrs)
 447 {
 448 }
 449
 450 static int __dummy_mmap(struct device *dev,
 451                         struct vm_area_struct *vma,
 452                         void *cpu_addr, dma_addr_t dma_addr, size_t size,
 453                         unsigned long attrs)
 454 {
 455         return -ENXIO;
 456 }
 457
 458 static dma_addr_t __dummy_map_page(struct device *dev, struct page *page,
 459                                    unsigned long offset, size_t size,
 460                                    enum dma_data_direction dir,
 461                                    unsigned long attrs)
 462 {
 463         return DMA_ERROR_CODE;
 464 }
 465
 466 static void __dummy_unmap_page(struct device *dev, dma_addr_t dev_addr,
 467                                size_t size, enum dma_data_direction dir,
 468                                unsigned long attrs)
 469 {
 470 }
 471
 472 static int __dummy_map_sg(struct device *dev, struct scatterlist *sgl,
 473                           int nelems, enum dma_data_direction dir,
 474                           unsigned long attrs)
 475 {
 476         return 0;
 477 }
 478
 479 static void __dummy_unmap_sg(struct device *dev,
 480                              struct scatterlist *sgl, int nelems,
 481                              enum dma_data_direction dir,
 482                              unsigned long attrs)
 483 {
 484 }
 485
 486 static void __dummy_sync_single(struct device *dev,
 487                                 dma_addr_t dev_addr, size_t size,
 488                                 enum dma_data_direction dir)
 489 {
 490 }
 491
 492 static void __dummy_sync_sg(struct device *dev,
 493                             struct scatterlist *sgl, int nelems,
 494                             enum dma_data_direction dir)
 495 {
 496 }
 497
 498 static int __dummy_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
 499 {
 500         return 1;
 501 }
 502
 503 static int __dummy_dma_supported(struct device *hwdev, u64 mask)
 504 {
 505         return 0;
 506 }
 507
 508 struct dma_map_ops dummy_dma_ops = {
 509         .alloc                  = __dummy_alloc,
 510         .free                   = __dummy_free,
 511         .mmap                   = __dummy_mmap,
 512         .map_page               = __dummy_map_page,
 513         .unmap_page             = __dummy_unmap_page,
 514         .map_sg                 = __dummy_map_sg,
 515         .unmap_sg               = __dummy_unmap_sg,
 516         .sync_single_for_cpu    = __dummy_sync_single,
 517         .sync_single_for_device = __dummy_sync_single,
 518         .sync_sg_for_cpu        = __dummy_sync_sg,
 519         .sync_sg_for_device     = __dummy_sync_sg,
 520         .mapping_error          = __dummy_mapping_error,
 521         .dma_supported          = __dummy_dma_supported,
 522 };
 523 EXPORT_SYMBOL(dummy_dma_ops);
 524
 525 static int __init arm64_dma_init(void)
 526 {
 527         if (swiotlb_force || max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT))
 528                 swiotlb = 1;
 529
 530         return atomic_pool_init();
 531 }
 532 arch_initcall(arm64_dma_init);
 533
 534 #define PREALLOC_DMA_DEBUG_ENTRIES      4096
 535
 536 static int __init dma_debug_do_init(void)
 537 {
 538         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 539         return 0;
 540 }
 541 fs_initcall(dma_debug_do_init);
 542
 543
 544 #ifdef CONFIG_IOMMU_DMA
 545 #include <linux/dma-iommu.h>
 546 #include <linux/platform_device.h>
 547 #include <linux/amba/bus.h>
 548
 549 /* Thankfully, all cache ops are by VA so we can ignore phys here */
 550 static void flush_page(struct device *dev, const void *virt, phys_addr_t phys)
 551 {
 552         __dma_flush_area(virt, PAGE_SIZE);
 553 }
 554
 555 static void *__iommu_alloc_attrs(struct device *dev, size_t size,
 556                                  dma_addr_t *handle, gfp_t gfp,
 557                                  unsigned long attrs)
 558 {
 559         bool coherent = is_device_dma_coherent(dev);
 560         int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent);
 561         size_t iosize = size;
 562         void *addr;
 563
 564         if (WARN(!dev, "cannot create IOMMU mapping for unknown device\n"))
 565                 return NULL;
 566
 567         size = PAGE_ALIGN(size);
 568
 569         /*
 570          * Some drivers rely on this, and we probably don't want the
 571          * possibility of stale kernel data being read by devices anyway.
 572          */
 573         gfp |= __GFP_ZERO;
 574
 575         if (gfpflags_allow_blocking(gfp)) {
 576                 struct page **pages;
 577                 pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, coherent);
 578
 579                 pages = iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
 580                                         handle, flush_page);
 581                 if (!pages)
 582                         return NULL;
 583
 584                 addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
 585                                               __builtin_return_address(0));
 586                 if (!addr)
 587                         iommu_dma_free(dev, pages, iosize, handle);
 588         } else {
 589                 struct page *page;
 590                 /*
 591                  * In atomic context we can't remap anything, so we'll only
 592                  * get the virtually contiguous buffer we need by way of a
 593                  * physically contiguous allocation.
 594                  */
 595                 if (coherent) {
 596                         page = alloc_pages(gfp, get_order(size));
 597                         addr = page ? page_address(page) : NULL;
 598                 } else {
 599                         addr = __alloc_from_pool(size, &page, gfp);
 600                 }
 601                 if (!addr)
 602                         return NULL;
 603
 604                 *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot);
 605                 if (iommu_dma_mapping_error(dev, *handle)) {
 606                         if (coherent)
 607                                 __free_pages(page, get_order(size));
 608                         else
 609                                 __free_from_pool(addr, size);
 610                         addr = NULL;
 611                 }
 612         }
 613         return addr;
 614 }
 615
 616 static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 617                                dma_addr_t handle, unsigned long attrs)
 618 {
 619         size_t iosize = size;
 620
 621         size = PAGE_ALIGN(size);
 622         /*
 623          * @cpu_addr will be one of 3 things depending on how it was allocated:
 624          * - A remapped array of pages from iommu_dma_alloc(), for all
 625          *   non-atomic allocations.
 626          * - A non-cacheable alias from the atomic pool, for atomic
 627          *   allocations by non-coherent devices.
 628          * - A normal lowmem address, for atomic allocations by
 629          *   coherent devices.
 630          * Hence how dodgy the below logic looks...
 631          */
 632         if (__in_atomic_pool(cpu_addr, size)) {
 633                 iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
 634                 __free_from_pool(cpu_addr, size);
 635         } else if (is_vmalloc_addr(cpu_addr)){
 636                 struct vm_struct *area = find_vm_area(cpu_addr);
 637
 638                 if (WARN_ON(!area || !area->pages))
 639                         return;
 640                 iommu_dma_free(dev, area->pages, iosize, &handle);
 641                 dma_common_free_remap(cpu_addr, size, VM_USERMAP);
 642         } else {
 643                 iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
 644                 __free_pages(virt_to_page(cpu_addr), get_order(size));
 645         }
 646 }
 647
 648 static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
 649                               void *cpu_addr, dma_addr_t dma_addr, size_t size,
 650                               unsigned long attrs)
 651 {
 652         struct vm_struct *area;
 653         int ret;
 654
 655         vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
 656                                              is_device_dma_coherent(dev));
 657
 658         if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 659                 return ret;
 660
 661         area = find_vm_area(cpu_addr);
 662         if (WARN_ON(!area || !area->pages))
 663                 return -ENXIO;
 664
 665         return iommu_dma_mmap(area->pages, size, vma);
 666 }
 667
 668 static int __iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
 669                                void *cpu_addr, dma_addr_t dma_addr,
 670                                size_t size, unsigned long attrs)
 671 {
 672         unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 673         struct vm_struct *area = find_vm_area(cpu_addr);
 674
 675         if (WARN_ON(!area || !area->pages))
 676                 return -ENXIO;
 677
 678         return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size,
 679                                          GFP_KERNEL);
 680 }
 681
 682 static void __iommu_sync_single_for_cpu(struct device *dev,
 683                                         dma_addr_t dev_addr, size_t size,
 684                                         enum dma_data_direction dir)
 685 {
 686         phys_addr_t phys;
 687
 688         if (is_device_dma_coherent(dev))
 689                 return;
 690
 691         phys = iommu_iova_to_phys(iommu_get_domain_for_dev(dev), dev_addr);
 692         __dma_unmap_area(phys_to_virt(phys), size, dir);
 693 }
 694
 695 static void __iommu_sync_single_for_device(struct device *dev,
 696                                            dma_addr_t dev_addr, size_t size,
 697                                            enum dma_data_direction dir)
 698 {
 699         phys_addr_t phys;
 700
 701         if (is_device_dma_coherent(dev))
 702                 return;
 703
 704         phys = iommu_iova_to_phys(iommu_get_domain_for_dev(dev), dev_addr);
 705         __dma_map_area(phys_to_virt(phys), size, dir);
 706 }
 707
 708 static dma_addr_t __iommu_map_page(struct device *dev, struct page *page,
 709                                    unsigned long offset, size_t size,
 710                                    enum dma_data_direction dir,
 711                                    unsigned long attrs)
 712 {
 713         bool coherent = is_device_dma_coherent(dev);
 714         int prot = dma_direction_to_prot(dir, coherent);
 715         dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
 716
 717         if (!iommu_dma_mapping_error(dev, dev_addr) &&
 718             (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 719                 __iommu_sync_single_for_device(dev, dev_addr, size, dir);
 720
 721         return dev_addr;
 722 }
 723
 724 static void __iommu_unmap_page(struct device *dev, dma_addr_t dev_addr,
 725                                size_t size, enum dma_data_direction dir,
 726                                unsigned long attrs)
 727 {
 728         if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 729                 __iommu_sync_single_for_cpu(dev, dev_addr, size, dir);
 730
 731         iommu_dma_unmap_page(dev, dev_addr, size, dir, attrs);
 732 }
 733
 734 static void __iommu_sync_sg_for_cpu(struct device *dev,
 735                                     struct scatterlist *sgl, int nelems,
 736                                     enum dma_data_direction dir)
 737 {
 738         struct scatterlist *sg;
 739         int i;
 740
 741         if (is_device_dma_coherent(dev))
 742                 return;
 743
 744         for_each_sg(sgl, sg, nelems, i)
 745                 __dma_unmap_area(sg_virt(sg), sg->length, dir);
 746 }
 747
 748 static void __iommu_sync_sg_for_device(struct device *dev,
 749                                        struct scatterlist *sgl, int nelems,
 750                                        enum dma_data_direction dir)
 751 {
 752         struct scatterlist *sg;
 753         int i;
 754
 755         if (is_device_dma_coherent(dev))
 756                 return;
 757
 758         for_each_sg(sgl, sg, nelems, i)
 759                 __dma_map_area(sg_virt(sg), sg->length, dir);
 760 }
 761
 762 static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 763                                 int nelems, enum dma_data_direction dir,
 764                                 unsigned long attrs)
 765 {
 766         bool coherent = is_device_dma_coherent(dev);
 767
 768         if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 769                 __iommu_sync_sg_for_device(dev, sgl, nelems, dir);
 770
 771         return iommu_dma_map_sg(dev, sgl, nelems,
 772                         dma_direction_to_prot(dir, coherent));
 773 }
 774
 775 static void __iommu_unmap_sg_attrs(struct device *dev,
 776                                    struct scatterlist *sgl, int nelems,
 777                                    enum dma_data_direction dir,
 778                                    unsigned long attrs)
 779 {
 780         if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 781                 __iommu_sync_sg_for_cpu(dev, sgl, nelems, dir);
 782
 783         iommu_dma_unmap_sg(dev, sgl, nelems, dir, attrs);
 784 }
 785
 786 static struct dma_map_ops iommu_dma_ops = {
 787         .alloc = __iommu_alloc_attrs,
 788         .free = __iommu_free_attrs,
 789         .mmap = __iommu_mmap_attrs,
 790         .get_sgtable = __iommu_get_sgtable,
 791         .map_page = __iommu_map_page,
 792         .unmap_page = __iommu_unmap_page,
 793         .map_sg = __iommu_map_sg_attrs,
 794         .unmap_sg = __iommu_unmap_sg_attrs,
 795         .sync_single_for_cpu = __iommu_sync_single_for_cpu,
 796         .sync_single_for_device = __iommu_sync_single_for_device,
 797         .sync_sg_for_cpu = __iommu_sync_sg_for_cpu,
 798         .sync_sg_for_device = __iommu_sync_sg_for_device,
 799         .dma_supported = iommu_dma_supported,
 800         .mapping_error = iommu_dma_mapping_error,
 801 };
 802
 803 /*
 804  * TODO: Right now __iommu_setup_dma_ops() gets called too early to do
 805  * everything it needs to - the device is only partially created and the
 806  * IOMMU driver hasn't seen it yet, so it can't have a group. Thus we
 807  * need this delayed attachment dance. Once IOMMU probe ordering is sorted
 808  * to move the arch_setup_dma_ops() call later, all the notifier bits below
 809  * become unnecessary, and will go away.
 810  */
 811 struct iommu_dma_notifier_data {
 812         struct list_head list;
 813         struct device *dev;
 814         const struct iommu_ops *ops;
 815         u64 dma_base;
 816         u64 size;
 817 };
 818 static LIST_HEAD(iommu_dma_masters);
 819 static DEFINE_MUTEX(iommu_dma_notifier_lock);
 820
 821 static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops,
 822                            u64 dma_base, u64 size)
 823 {
 824         struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
 825
 826         /*
 827          * If the IOMMU driver has the DMA domain support that we require,
 828          * then the IOMMU core will have already configured a group for this
 829          * device, and allocated the default domain for that group.
 830          */
 831         if (!domain || iommu_dma_init_domain(domain, dma_base, size)) {
 832                 pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
 833                         dev_name(dev));
 834                 return false;
 835         }
 836
 837         dev->archdata.dma_ops = &iommu_dma_ops;
 838         return true;
 839 }
 840
 841 static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops,
 842                               u64 dma_base, u64 size)
 843 {
 844         struct iommu_dma_notifier_data *iommudata;
 845
 846         iommudata = kzalloc(sizeof(*iommudata), GFP_KERNEL);
 847         if (!iommudata)
 848                 return;
 849
 850         iommudata->dev = dev;
 851         iommudata->ops = ops;
 852         iommudata->dma_base = dma_base;
 853         iommudata->size = size;
 854
 855         mutex_lock(&iommu_dma_notifier_lock);
 856         list_add(&iommudata->list, &iommu_dma_masters);
 857         mutex_unlock(&iommu_dma_notifier_lock);
 858 }
 859
 860 static int __iommu_attach_notifier(struct notifier_block *nb,
 861                                    unsigned long action, void *data)
 862 {
 863         struct iommu_dma_notifier_data *master, *tmp;
 864
 865         if (action != BUS_NOTIFY_BIND_DRIVER)
 866                 return 0;
 867
 868         mutex_lock(&iommu_dma_notifier_lock);
 869         list_for_each_entry_safe(master, tmp, &iommu_dma_masters, list) {
 870                 if (data == master->dev && do_iommu_attach(master->dev,
 871                                 master->ops, master->dma_base, master->size)) {
 872                         list_del(&master->list);
 873                         kfree(master);
 874                         break;
 875                 }
 876         }
 877         mutex_unlock(&iommu_dma_notifier_lock);
 878         return 0;
 879 }
 880
 881 static int __init register_iommu_dma_ops_notifier(struct bus_type *bus)
 882 {
 883         struct notifier_block *nb = kzalloc(sizeof(*nb), GFP_KERNEL);
 884         int ret;
 885
 886         if (!nb)
 887                 return -ENOMEM;
 888
 889         nb->notifier_call = __iommu_attach_notifier;
 890
 891         ret = bus_register_notifier(bus, nb);
 892         if (ret) {
 893                 pr_warn("Failed to register DMA domain notifier; IOMMU DMA ops unavailable on bus '%s'\n",
 894                         bus->name);
 895                 kfree(nb);
 896         }
 897         return ret;
 898 }
 899
 900 static int __init __iommu_dma_init(void)
 901 {
 902         int ret;
 903
 904         ret = iommu_dma_init();
 905         if (!ret)
 906                 ret = register_iommu_dma_ops_notifier(&platform_bus_type);
 907         if (!ret)
 908                 ret = register_iommu_dma_ops_notifier(&amba_bustype);
 909 #ifdef CONFIG_PCI
 910         if (!ret)
 911                 ret = register_iommu_dma_ops_notifier(&pci_bus_type);
 912 #endif
 913         return ret;
 914 }
 915 arch_initcall(__iommu_dma_init);
 916
 917 static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 918                                   const struct iommu_ops *ops)
 919 {
 920         struct iommu_group *group;
 921
 922         if (!ops)
 923                 return;
 924         /*
 925          * TODO: As a concession to the future, we're ready to handle being
 926          * called both early and late (i.e. after bus_add_device). Once all
 927          * the platform bus code is reworked to call us late and the notifier
 928          * junk above goes away, move the body of do_iommu_attach here.
 929          */
 930         group = iommu_group_get(dev);
 931         if (group) {
 932                 do_iommu_attach(dev, ops, dma_base, size);
 933                 iommu_group_put(group);
 934         } else {
 935                 queue_iommu_attach(dev, ops, dma_base, size);
 936         }
 937 }
 938
 939 void arch_teardown_dma_ops(struct device *dev)
 940 {
 941         struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
 942
 943         if (WARN_ON(domain))
 944                 iommu_detach_device(domain, dev);
 945
 946         dev->archdata.dma_ops = NULL;
 947 }
 948
 949 #else
 950
 951 static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 952                                   const struct iommu_ops *iommu)
 953 { }
 954
 955 #endif  /* CONFIG_IOMMU_DMA */
 956
 957 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 958                         const struct iommu_ops *iommu, bool coherent)
 959 {
 960         if (!dev->archdata.dma_ops)
 961                 dev->archdata.dma_ops = &swiotlb_dma_ops;
 962
 963         dev->archdata.dma_coherent = coherent;
 964         __iommu_setup_dma_ops(dev, dma_base, size, iommu);
 965 }