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/export.h>
  22 #include <linux/slab.h>
  23 #include <linux/genalloc.h>
  24 #include <linux/dma-mapping.h>
  25 #include <linux/dma-contiguous.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/swiotlb.h>
  28
  29 #include <asm/cacheflush.h>
  30
  31 struct dma_map_ops *dma_ops;
  32 EXPORT_SYMBOL(dma_ops);
  33
  34 static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot,
  35                                  bool coherent)
  36 {
  37         if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
  38                 return pgprot_writecombine(prot);
  39         return prot;
  40 }
  41
  42 static struct gen_pool *atomic_pool;
  43
  44 #define DEFAULT_DMA_COHERENT_POOL_SIZE  SZ_256K
  45 static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE;
  46
  47 static int __init early_coherent_pool(char *p)
  48 {
  49         atomic_pool_size = memparse(p, &p);
  50         return 0;
  51 }
  52 early_param("coherent_pool", early_coherent_pool);
  53
  54 static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
  55 {
  56         unsigned long val;
  57         void *ptr = NULL;
  58
  59         if (!atomic_pool) {
  60                 WARN(1, "coherent pool not initialised!\n");
  61                 return NULL;
  62         }
  63
  64         val = gen_pool_alloc(atomic_pool, size);
  65         if (val) {
  66                 phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
  67
  68                 *ret_page = phys_to_page(phys);
  69                 ptr = (void *)val;
  70                 memset(ptr, 0, size);
  71         }
  72
  73         return ptr;
  74 }
  75
  76 static bool __in_atomic_pool(void *start, size_t size)
  77 {
  78         return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
  79 }
  80
  81 static int __free_from_pool(void *start, size_t size)
  82 {
  83         if (!__in_atomic_pool(start, size))
  84                 return 0;
  85
  86         gen_pool_free(atomic_pool, (unsigned long)start, size);
  87
  88         return 1;
  89 }
  90
  91 static void *__dma_alloc_coherent(struct device *dev, size_t size,
  92                                   dma_addr_t *dma_handle, gfp_t flags,
  93                                   struct dma_attrs *attrs)
  94 {
  95         if (dev == NULL) {
  96                 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
  97                 return NULL;
  98         }
  99
 100         if (IS_ENABLED(CONFIG_ZONE_DMA) &&
 101             dev->coherent_dma_mask <= DMA_BIT_MASK(32))
 102                 flags |= GFP_DMA;
 103         if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) {
 104                 struct page *page;
 105                 void *addr;
 106
 107                 page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
 108                                                         get_order(size));
 109                 if (!page)
 110                         return NULL;
 111
 112                 *dma_handle = phys_to_dma(dev, page_to_phys(page));
 113                 addr = page_address(page);
 114                 memset(addr, 0, size);
 115                 return addr;
 116         } else {
 117                 return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
 118         }
 119 }
 120
 121 static void __dma_free_coherent(struct device *dev, size_t size,
 122                                 void *vaddr, dma_addr_t dma_handle,
 123                                 struct dma_attrs *attrs)
 124 {
 125         bool freed;
 126         phys_addr_t paddr = dma_to_phys(dev, dma_handle);
 127
 128         if (dev == NULL) {
 129                 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
 130                 return;
 131         }
 132
 133         freed = dma_release_from_contiguous(dev,
 134                                         phys_to_page(paddr),
 135                                         size >> PAGE_SHIFT);
 136         if (!freed)
 137                 swiotlb_free_coherent(dev, size, vaddr, dma_handle);
 138 }
 139
 140 static void *__dma_alloc(struct device *dev, size_t size,
 141                          dma_addr_t *dma_handle, gfp_t flags,
 142                          struct dma_attrs *attrs)
 143 {
 144         struct page *page;
 145         void *ptr, *coherent_ptr;
 146         bool coherent = is_device_dma_coherent(dev);
 147
 148         size = PAGE_ALIGN(size);
 149
 150         if (!coherent && !(flags & __GFP_WAIT)) {
 151                 struct page *page = NULL;
 152                 void *addr = __alloc_from_pool(size, &page, flags);
 153
 154                 if (addr)
 155                         *dma_handle = phys_to_dma(dev, page_to_phys(page));
 156
 157                 return addr;
 158         }
 159
 160         ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
 161         if (!ptr)
 162                 goto no_mem;
 163
 164         /* no need for non-cacheable mapping if coherent */
 165         if (coherent)
 166                 return ptr;
 167
 168         /* remove any dirty cache lines on the kernel alias */
 169         __dma_flush_range(ptr, ptr + size);
 170
 171         /* create a coherent mapping */
 172         page = virt_to_page(ptr);
 173         coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
 174                                 __get_dma_pgprot(attrs,
 175                                         __pgprot(PROT_NORMAL_NC), false),
 176                                         NULL);
 177         if (!coherent_ptr)
 178                 goto no_map;
 179
 180         return coherent_ptr;
 181
 182 no_map:
 183         __dma_free_coherent(dev, size, ptr, *dma_handle, attrs);
 184 no_mem:
 185         *dma_handle = DMA_ERROR_CODE;
 186         return NULL;
 187 }
 188
 189 static void __dma_free(struct device *dev, size_t size,
 190                        void *vaddr, dma_addr_t dma_handle,
 191                        struct dma_attrs *attrs)
 192 {
 193         void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
 194
 195         size = PAGE_ALIGN(size);
 196
 197         if (!is_device_dma_coherent(dev)) {
 198                 if (__free_from_pool(vaddr, size))
 199                         return;
 200                 vunmap(vaddr);
 201         }
 202         __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs);
 203 }
 204
 205 static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
 206                                      unsigned long offset, size_t size,
 207                                      enum dma_data_direction dir,
 208                                      struct dma_attrs *attrs)
 209 {
 210         dma_addr_t dev_addr;
 211
 212         dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
 213         if (!is_device_dma_coherent(dev))
 214                 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 215
 216         return dev_addr;
 217 }
 218
 219
 220 static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
 221                                  size_t size, enum dma_data_direction dir,
 222                                  struct dma_attrs *attrs)
 223 {
 224         if (!is_device_dma_coherent(dev))
 225                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 226         swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
 227 }
 228
 229 static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 230                                   int nelems, enum dma_data_direction dir,
 231                                   struct dma_attrs *attrs)
 232 {
 233         struct scatterlist *sg;
 234         int i, ret;
 235
 236         ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
 237         if (!is_device_dma_coherent(dev))
 238                 for_each_sg(sgl, sg, ret, i)
 239                         __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 240                                        sg->length, dir);
 241
 242         return ret;
 243 }
 244
 245 static void __swiotlb_unmap_sg_attrs(struct device *dev,
 246                                      struct scatterlist *sgl, int nelems,
 247                                      enum dma_data_direction dir,
 248                                      struct dma_attrs *attrs)
 249 {
 250         struct scatterlist *sg;
 251         int i;
 252
 253         if (!is_device_dma_coherent(dev))
 254                 for_each_sg(sgl, sg, nelems, i)
 255                         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 256                                          sg->length, dir);
 257         swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
 258 }
 259
 260 static void __swiotlb_sync_single_for_cpu(struct device *dev,
 261                                           dma_addr_t dev_addr, size_t size,
 262                                           enum dma_data_direction dir)
 263 {
 264         if (!is_device_dma_coherent(dev))
 265                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 266         swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
 267 }
 268
 269 static void __swiotlb_sync_single_for_device(struct device *dev,
 270                                              dma_addr_t dev_addr, size_t size,
 271                                              enum dma_data_direction dir)
 272 {
 273         swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
 274         if (!is_device_dma_coherent(dev))
 275                 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 276 }
 277
 278 static void __swiotlb_sync_sg_for_cpu(struct device *dev,
 279                                       struct scatterlist *sgl, int nelems,
 280                                       enum dma_data_direction dir)
 281 {
 282         struct scatterlist *sg;
 283         int i;
 284
 285         if (!is_device_dma_coherent(dev))
 286                 for_each_sg(sgl, sg, nelems, i)
 287                         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 288                                          sg->length, dir);
 289         swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
 290 }
 291
 292 static void __swiotlb_sync_sg_for_device(struct device *dev,
 293                                          struct scatterlist *sgl, int nelems,
 294                                          enum dma_data_direction dir)
 295 {
 296         struct scatterlist *sg;
 297         int i;
 298
 299         swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
 300         if (!is_device_dma_coherent(dev))
 301                 for_each_sg(sgl, sg, nelems, i)
 302                         __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 303                                        sg->length, dir);
 304 }
 305
 306 static int __swiotlb_mmap(struct device *dev,
 307                           struct vm_area_struct *vma,
 308                           void *cpu_addr, dma_addr_t dma_addr, size_t size,
 309                           struct dma_attrs *attrs)
 310 {
 311         int ret = -ENXIO;
 312         unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
 313                                         PAGE_SHIFT;
 314         unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 315         unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
 316         unsigned long off = vma->vm_pgoff;
 317
 318         vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
 319                                              is_device_dma_coherent(dev));
 320
 321         if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 322                 return ret;
 323
 324         if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
 325                 ret = remap_pfn_range(vma, vma->vm_start,
 326                                       pfn + off,
 327                                       vma->vm_end - vma->vm_start,
 328                                       vma->vm_page_prot);
 329         }
 330
 331         return ret;
 332 }
 333
 334 static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
 335                                  void *cpu_addr, dma_addr_t handle, size_t size,
 336                                  struct dma_attrs *attrs)
 337 {
 338         int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 339
 340         if (!ret)
 341                 sg_set_page(sgt->sgl, phys_to_page(dma_to_phys(dev, handle)),
 342                             PAGE_ALIGN(size), 0);
 343
 344         return ret;
 345 }
 346
 347 static struct dma_map_ops swiotlb_dma_ops = {
 348         .alloc = __dma_alloc,
 349         .free = __dma_free,
 350         .mmap = __swiotlb_mmap,
 351         .get_sgtable = __swiotlb_get_sgtable,
 352         .map_page = __swiotlb_map_page,
 353         .unmap_page = __swiotlb_unmap_page,
 354         .map_sg = __swiotlb_map_sg_attrs,
 355         .unmap_sg = __swiotlb_unmap_sg_attrs,
 356         .sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
 357         .sync_single_for_device = __swiotlb_sync_single_for_device,
 358         .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
 359         .sync_sg_for_device = __swiotlb_sync_sg_for_device,
 360         .dma_supported = swiotlb_dma_supported,
 361         .mapping_error = swiotlb_dma_mapping_error,
 362 };
 363
 364 static int __init atomic_pool_init(void)
 365 {
 366         pgprot_t prot = __pgprot(PROT_NORMAL_NC);
 367         unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
 368         struct page *page;
 369         void *addr;
 370         unsigned int pool_size_order = get_order(atomic_pool_size);
 371
 372         if (dev_get_cma_area(NULL))
 373                 page = dma_alloc_from_contiguous(NULL, nr_pages,
 374                                                         pool_size_order);
 375         else
 376                 page = alloc_pages(GFP_DMA, pool_size_order);
 377
 378         if (page) {
 379                 int ret;
 380                 void *page_addr = page_address(page);
 381
 382                 memset(page_addr, 0, atomic_pool_size);
 383                 __dma_flush_range(page_addr, page_addr + atomic_pool_size);
 384
 385                 atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
 386                 if (!atomic_pool)
 387                         goto free_page;
 388
 389                 addr = dma_common_contiguous_remap(page, atomic_pool_size,
 390                                         VM_USERMAP, prot, atomic_pool_init);
 391
 392                 if (!addr)
 393                         goto destroy_genpool;
 394
 395                 ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
 396                                         page_to_phys(page),
 397                                         atomic_pool_size, -1);
 398                 if (ret)
 399                         goto remove_mapping;
 400
 401                 gen_pool_set_algo(atomic_pool,
 402                                   gen_pool_first_fit_order_align,
 403                                   (void *)PAGE_SHIFT);
 404
 405                 pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
 406                         atomic_pool_size / 1024);
 407                 return 0;
 408         }
 409         goto out;
 410
 411 remove_mapping:
 412         dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
 413 destroy_genpool:
 414         gen_pool_destroy(atomic_pool);
 415         atomic_pool = NULL;
 416 free_page:
 417         if (!dma_release_from_contiguous(NULL, page, nr_pages))
 418                 __free_pages(page, pool_size_order);
 419 out:
 420         pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
 421                 atomic_pool_size / 1024);
 422         return -ENOMEM;
 423 }
 424
 425 /********************************************
 426  * The following APIs are for dummy DMA ops *
 427  ********************************************/
 428
 429 static void *__dummy_alloc(struct device *dev, size_t size,
 430                            dma_addr_t *dma_handle, gfp_t flags,
 431                            struct dma_attrs *attrs)
 432 {
 433         return NULL;
 434 }
 435
 436 static void __dummy_free(struct device *dev, size_t size,
 437                          void *vaddr, dma_addr_t dma_handle,
 438                          struct dma_attrs *attrs)
 439 {
 440 }
 441
 442 static int __dummy_mmap(struct device *dev,
 443                         struct vm_area_struct *vma,
 444                         void *cpu_addr, dma_addr_t dma_addr, size_t size,
 445                         struct dma_attrs *attrs)
 446 {
 447         return -ENXIO;
 448 }
 449
 450 static dma_addr_t __dummy_map_page(struct device *dev, struct page *page,
 451                                    unsigned long offset, size_t size,
 452                                    enum dma_data_direction dir,
 453                                    struct dma_attrs *attrs)
 454 {
 455         return DMA_ERROR_CODE;
 456 }
 457
 458 static void __dummy_unmap_page(struct device *dev, dma_addr_t dev_addr,
 459                                size_t size, enum dma_data_direction dir,
 460                                struct dma_attrs *attrs)
 461 {
 462 }
 463
 464 static int __dummy_map_sg(struct device *dev, struct scatterlist *sgl,
 465                           int nelems, enum dma_data_direction dir,
 466                           struct dma_attrs *attrs)
 467 {
 468         return 0;
 469 }
 470
 471 static void __dummy_unmap_sg(struct device *dev,
 472                              struct scatterlist *sgl, int nelems,
 473                              enum dma_data_direction dir,
 474                              struct dma_attrs *attrs)
 475 {
 476 }
 477
 478 static void __dummy_sync_single(struct device *dev,
 479                                 dma_addr_t dev_addr, size_t size,
 480                                 enum dma_data_direction dir)
 481 {
 482 }
 483
 484 static void __dummy_sync_sg(struct device *dev,
 485                             struct scatterlist *sgl, int nelems,
 486                             enum dma_data_direction dir)
 487 {
 488 }
 489
 490 static int __dummy_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
 491 {
 492         return 1;
 493 }
 494
 495 static int __dummy_dma_supported(struct device *hwdev, u64 mask)
 496 {
 497         return 0;
 498 }
 499
 500 struct dma_map_ops dummy_dma_ops = {
 501         .alloc                  = __dummy_alloc,
 502         .free                   = __dummy_free,
 503         .mmap                   = __dummy_mmap,
 504         .map_page               = __dummy_map_page,
 505         .unmap_page             = __dummy_unmap_page,
 506         .map_sg                 = __dummy_map_sg,
 507         .unmap_sg               = __dummy_unmap_sg,
 508         .sync_single_for_cpu    = __dummy_sync_single,
 509         .sync_single_for_device = __dummy_sync_single,
 510         .sync_sg_for_cpu        = __dummy_sync_sg,
 511         .sync_sg_for_device     = __dummy_sync_sg,
 512         .mapping_error          = __dummy_mapping_error,
 513         .dma_supported          = __dummy_dma_supported,
 514 };
 515 EXPORT_SYMBOL(dummy_dma_ops);
 516
 517 static int __init arm64_dma_init(void)
 518 {
 519         int ret;
 520
 521         dma_ops = &swiotlb_dma_ops;
 522
 523         ret = atomic_pool_init();
 524
 525         return ret;
 526 }
 527 arch_initcall(arm64_dma_init);
 528
 529 #define PREALLOC_DMA_DEBUG_ENTRIES      4096
 530
 531 static int __init dma_debug_do_init(void)
 532 {
 533         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 534         return 0;
 535 }
 536 fs_initcall(dma_debug_do_init);