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)
  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         }
  71
  72         return ptr;
  73 }
  74
  75 static bool __in_atomic_pool(void *start, size_t size)
  76 {
  77         return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
  78 }
  79
  80 static int __free_from_pool(void *start, size_t size)
  81 {
  82         if (!__in_atomic_pool(start, size))
  83                 return 0;
  84
  85         gen_pool_free(atomic_pool, (unsigned long)start, size);
  86
  87         return 1;
  88 }
  89
  90 static void *__dma_alloc_coherent(struct device *dev, size_t size,
  91                                   dma_addr_t *dma_handle, gfp_t flags,
  92                                   struct dma_attrs *attrs)
  93 {
  94         if (dev == NULL) {
  95                 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
  96                 return NULL;
  97         }
  98
  99         if (IS_ENABLED(CONFIG_ZONE_DMA) &&
 100             dev->coherent_dma_mask <= DMA_BIT_MASK(32))
 101                 flags |= GFP_DMA;
 102         if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) {
 103                 struct page *page;
 104
 105                 size = PAGE_ALIGN(size);
 106                 page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
 107                                                         get_order(size));
 108                 if (!page)
 109                         return NULL;
 110
 111                 *dma_handle = phys_to_dma(dev, page_to_phys(page));
 112                 return page_address(page);
 113         } else {
 114                 return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
 115         }
 116 }
 117
 118 static void __dma_free_coherent(struct device *dev, size_t size,
 119                                 void *vaddr, dma_addr_t dma_handle,
 120                                 struct dma_attrs *attrs)
 121 {
 122         bool freed;
 123         phys_addr_t paddr = dma_to_phys(dev, dma_handle);
 124
 125         if (dev == NULL) {
 126                 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
 127                 return;
 128         }
 129
 130         freed = dma_release_from_contiguous(dev,
 131                                         phys_to_page(paddr),
 132                                         size >> PAGE_SHIFT);
 133         if (!freed)
 134                 swiotlb_free_coherent(dev, size, vaddr, dma_handle);
 135 }
 136
 137 static void *__dma_alloc_noncoherent(struct device *dev, size_t size,
 138                                      dma_addr_t *dma_handle, gfp_t flags,
 139                                      struct dma_attrs *attrs)
 140 {
 141         struct page *page;
 142         void *ptr, *coherent_ptr;
 143
 144         size = PAGE_ALIGN(size);
 145
 146         if (!(flags & __GFP_WAIT)) {
 147                 struct page *page = NULL;
 148                 void *addr = __alloc_from_pool(size, &page);
 149
 150                 if (addr)
 151                         *dma_handle = phys_to_dma(dev, page_to_phys(page));
 152
 153                 return addr;
 154
 155         }
 156
 157         ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
 158         if (!ptr)
 159                 goto no_mem;
 160
 161         /* remove any dirty cache lines on the kernel alias */
 162         __dma_flush_range(ptr, ptr + size);
 163
 164         /* create a coherent mapping */
 165         page = virt_to_page(ptr);
 166         coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
 167                                 __get_dma_pgprot(attrs,
 168                                         __pgprot(PROT_NORMAL_NC), false),
 169                                         NULL);
 170         if (!coherent_ptr)
 171                 goto no_map;
 172
 173         return coherent_ptr;
 174
 175 no_map:
 176         __dma_free_coherent(dev, size, ptr, *dma_handle, attrs);
 177 no_mem:
 178         *dma_handle = DMA_ERROR_CODE;
 179         return NULL;
 180 }
 181
 182 static void __dma_free_noncoherent(struct device *dev, size_t size,
 183                                    void *vaddr, dma_addr_t dma_handle,
 184                                    struct dma_attrs *attrs)
 185 {
 186         void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
 187
 188         if (__free_from_pool(vaddr, size))
 189                 return;
 190         vunmap(vaddr);
 191         __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs);
 192 }
 193
 194 static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
 195                                      unsigned long offset, size_t size,
 196                                      enum dma_data_direction dir,
 197                                      struct dma_attrs *attrs)
 198 {
 199         dma_addr_t dev_addr;
 200
 201         dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
 202         __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 203
 204         return dev_addr;
 205 }
 206
 207
 208 static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
 209                                  size_t size, enum dma_data_direction dir,
 210                                  struct dma_attrs *attrs)
 211 {
 212         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 213         swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
 214 }
 215
 216 static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 217                                   int nelems, enum dma_data_direction dir,
 218                                   struct dma_attrs *attrs)
 219 {
 220         struct scatterlist *sg;
 221         int i, ret;
 222
 223         ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
 224         for_each_sg(sgl, sg, ret, i)
 225                 __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 226                                sg->length, dir);
 227
 228         return ret;
 229 }
 230
 231 static void __swiotlb_unmap_sg_attrs(struct device *dev,
 232                                      struct scatterlist *sgl, int nelems,
 233                                      enum dma_data_direction dir,
 234                                      struct dma_attrs *attrs)
 235 {
 236         struct scatterlist *sg;
 237         int i;
 238
 239         for_each_sg(sgl, sg, nelems, i)
 240                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 241                                  sg->length, dir);
 242         swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
 243 }
 244
 245 static void __swiotlb_sync_single_for_cpu(struct device *dev,
 246                                           dma_addr_t dev_addr, size_t size,
 247                                           enum dma_data_direction dir)
 248 {
 249         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 250         swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
 251 }
 252
 253 static void __swiotlb_sync_single_for_device(struct device *dev,
 254                                              dma_addr_t dev_addr, size_t size,
 255                                              enum dma_data_direction dir)
 256 {
 257         swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
 258         __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 259 }
 260
 261 static void __swiotlb_sync_sg_for_cpu(struct device *dev,
 262                                       struct scatterlist *sgl, int nelems,
 263                                       enum dma_data_direction dir)
 264 {
 265         struct scatterlist *sg;
 266         int i;
 267
 268         for_each_sg(sgl, sg, nelems, i)
 269                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 270                                  sg->length, dir);
 271         swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
 272 }
 273
 274 static void __swiotlb_sync_sg_for_device(struct device *dev,
 275                                          struct scatterlist *sgl, int nelems,
 276                                          enum dma_data_direction dir)
 277 {
 278         struct scatterlist *sg;
 279         int i;
 280
 281         swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
 282         for_each_sg(sgl, sg, nelems, i)
 283                 __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 284                                sg->length, dir);
 285 }
 286
 287 /* vma->vm_page_prot must be set appropriately before calling this function */
 288 static int __dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 289                              void *cpu_addr, dma_addr_t dma_addr, size_t size)
 290 {
 291         int ret = -ENXIO;
 292         unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
 293                                         PAGE_SHIFT;
 294         unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 295         unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
 296         unsigned long off = vma->vm_pgoff;
 297
 298         if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 299                 return ret;
 300
 301         if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
 302                 ret = remap_pfn_range(vma, vma->vm_start,
 303                                       pfn + off,
 304                                       vma->vm_end - vma->vm_start,
 305                                       vma->vm_page_prot);
 306         }
 307
 308         return ret;
 309 }
 310
 311 static int __swiotlb_mmap_noncoherent(struct device *dev,
 312                 struct vm_area_struct *vma,
 313                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 314                 struct dma_attrs *attrs)
 315 {
 316         vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot, false);
 317         return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
 318 }
 319
 320 static int __swiotlb_mmap_coherent(struct device *dev,
 321                 struct vm_area_struct *vma,
 322                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 323                 struct dma_attrs *attrs)
 324 {
 325         /* Just use whatever page_prot attributes were specified */
 326         return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
 327 }
 328
 329 struct dma_map_ops noncoherent_swiotlb_dma_ops = {
 330         .alloc = __dma_alloc_noncoherent,
 331         .free = __dma_free_noncoherent,
 332         .mmap = __swiotlb_mmap_noncoherent,
 333         .map_page = __swiotlb_map_page,
 334         .unmap_page = __swiotlb_unmap_page,
 335         .map_sg = __swiotlb_map_sg_attrs,
 336         .unmap_sg = __swiotlb_unmap_sg_attrs,
 337         .sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
 338         .sync_single_for_device = __swiotlb_sync_single_for_device,
 339         .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
 340         .sync_sg_for_device = __swiotlb_sync_sg_for_device,
 341         .dma_supported = swiotlb_dma_supported,
 342         .mapping_error = swiotlb_dma_mapping_error,
 343 };
 344 EXPORT_SYMBOL(noncoherent_swiotlb_dma_ops);
 345
 346 struct dma_map_ops coherent_swiotlb_dma_ops = {
 347         .alloc = __dma_alloc_coherent,
 348         .free = __dma_free_coherent,
 349         .mmap = __swiotlb_mmap_coherent,
 350         .map_page = swiotlb_map_page,
 351         .unmap_page = swiotlb_unmap_page,
 352         .map_sg = swiotlb_map_sg_attrs,
 353         .unmap_sg = swiotlb_unmap_sg_attrs,
 354         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
 355         .sync_single_for_device = swiotlb_sync_single_for_device,
 356         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
 357         .sync_sg_for_device = swiotlb_sync_sg_for_device,
 358         .dma_supported = swiotlb_dma_supported,
 359         .mapping_error = swiotlb_dma_mapping_error,
 360 };
 361 EXPORT_SYMBOL(coherent_swiotlb_dma_ops);
 362
 363 extern int swiotlb_late_init_with_default_size(size_t default_size);
 364
 365 static int __init atomic_pool_init(void)
 366 {
 367         pgprot_t prot = __pgprot(PROT_NORMAL_NC);
 368         unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
 369         struct page *page;
 370         void *addr;
 371         unsigned int pool_size_order = get_order(atomic_pool_size);
 372
 373         if (dev_get_cma_area(NULL))
 374                 page = dma_alloc_from_contiguous(NULL, nr_pages,
 375                                                         pool_size_order);
 376         else
 377                 page = alloc_pages(GFP_DMA, pool_size_order);
 378
 379         if (page) {
 380                 int ret;
 381                 void *page_addr = page_address(page);
 382
 383                 memset(page_addr, 0, atomic_pool_size);
 384                 __dma_flush_range(page_addr, page_addr + atomic_pool_size);
 385
 386                 atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
 387                 if (!atomic_pool)
 388                         goto free_page;
 389
 390                 addr = dma_common_contiguous_remap(page, atomic_pool_size,
 391                                         VM_USERMAP, prot, atomic_pool_init);
 392
 393                 if (!addr)
 394                         goto destroy_genpool;
 395
 396                 ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
 397                                         page_to_phys(page),
 398                                         atomic_pool_size, -1);
 399                 if (ret)
 400                         goto remove_mapping;
 401
 402                 gen_pool_set_algo(atomic_pool,
 403                                   gen_pool_first_fit_order_align,
 404                                   (void *)PAGE_SHIFT);
 405
 406                 pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
 407                         atomic_pool_size / 1024);
 408                 return 0;
 409         }
 410         goto out;
 411
 412 remove_mapping:
 413         dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
 414 destroy_genpool:
 415         gen_pool_destroy(atomic_pool);
 416         atomic_pool = NULL;
 417 free_page:
 418         if (!dma_release_from_contiguous(NULL, page, nr_pages))
 419                 __free_pages(page, pool_size_order);
 420 out:
 421         pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
 422                 atomic_pool_size / 1024);
 423         return -ENOMEM;
 424 }
 425
 426 static int __init swiotlb_late_init(void)
 427 {
 428         size_t swiotlb_size = min(SZ_64M, MAX_ORDER_NR_PAGES << PAGE_SHIFT);
 429
 430         dma_ops = &noncoherent_swiotlb_dma_ops;
 431
 432         return swiotlb_late_init_with_default_size(swiotlb_size);
 433 }
 434
 435 static int __init arm64_dma_init(void)
 436 {
 437         int ret = 0;
 438
 439         ret |= swiotlb_late_init();
 440         ret |= atomic_pool_init();
 441
 442         return ret;
 443 }
 444 arch_initcall(arm64_dma_init);
 445
 446 #define PREALLOC_DMA_DEBUG_ENTRIES      4096
 447
 448 static int __init dma_debug_do_init(void)
 449 {
 450         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 451         return 0;
 452 }
 453 fs_initcall(dma_debug_do_init);