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(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         bool coherent = is_device_dma_coherent(dev);
 144
 145         size = PAGE_ALIGN(size);
 146
 147         if (!coherent && !(flags & __GFP_WAIT)) {
 148                 struct page *page = NULL;
 149                 void *addr = __alloc_from_pool(size, &page);
 150
 151                 if (addr)
 152                         *dma_handle = phys_to_dma(dev, page_to_phys(page));
 153
 154                 return addr;
 155         }
 156
 157         ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
 158         if (!ptr)
 159                 goto no_mem;
 160
 161         /* no need for non-cacheable mapping if coherent */
 162         if (coherent)
 163                 return ptr;
 164
 165         /* remove any dirty cache lines on the kernel alias */
 166         __dma_flush_range(ptr, ptr + size);
 167
 168         /* create a coherent mapping */
 169         page = virt_to_page(ptr);
 170         coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
 171                                 __get_dma_pgprot(attrs,
 172                                         __pgprot(PROT_NORMAL_NC), false),
 173                                         NULL);
 174         if (!coherent_ptr)
 175                 goto no_map;
 176
 177         return coherent_ptr;
 178
 179 no_map:
 180         __dma_free_coherent(dev, size, ptr, *dma_handle, attrs);
 181 no_mem:
 182         *dma_handle = DMA_ERROR_CODE;
 183         return NULL;
 184 }
 185
 186 static void __dma_free(struct device *dev, size_t size,
 187                        void *vaddr, dma_addr_t dma_handle,
 188                        struct dma_attrs *attrs)
 189 {
 190         void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
 191
 192         if (!is_device_dma_coherent(dev)) {
 193                 if (__free_from_pool(vaddr, size))
 194                         return;
 195                 vunmap(vaddr);
 196         }
 197         __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs);
 198 }
 199
 200 static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
 201                                      unsigned long offset, size_t size,
 202                                      enum dma_data_direction dir,
 203                                      struct dma_attrs *attrs)
 204 {
 205         dma_addr_t dev_addr;
 206
 207         dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
 208         if (!is_device_dma_coherent(dev))
 209                 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 210
 211         return dev_addr;
 212 }
 213
 214
 215 static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
 216                                  size_t size, enum dma_data_direction dir,
 217                                  struct dma_attrs *attrs)
 218 {
 219         if (!is_device_dma_coherent(dev))
 220                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 221         swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
 222 }
 223
 224 static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
 225                                   int nelems, enum dma_data_direction dir,
 226                                   struct dma_attrs *attrs)
 227 {
 228         struct scatterlist *sg;
 229         int i, ret;
 230
 231         ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
 232         if (!is_device_dma_coherent(dev))
 233                 for_each_sg(sgl, sg, ret, i)
 234                         __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 235                                        sg->length, dir);
 236
 237         return ret;
 238 }
 239
 240 static void __swiotlb_unmap_sg_attrs(struct device *dev,
 241                                      struct scatterlist *sgl, int nelems,
 242                                      enum dma_data_direction dir,
 243                                      struct dma_attrs *attrs)
 244 {
 245         struct scatterlist *sg;
 246         int i;
 247
 248         if (!is_device_dma_coherent(dev))
 249                 for_each_sg(sgl, sg, nelems, i)
 250                         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 251                                          sg->length, dir);
 252         swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
 253 }
 254
 255 static void __swiotlb_sync_single_for_cpu(struct device *dev,
 256                                           dma_addr_t dev_addr, size_t size,
 257                                           enum dma_data_direction dir)
 258 {
 259         if (!is_device_dma_coherent(dev))
 260                 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 261         swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
 262 }
 263
 264 static void __swiotlb_sync_single_for_device(struct device *dev,
 265                                              dma_addr_t dev_addr, size_t size,
 266                                              enum dma_data_direction dir)
 267 {
 268         swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
 269         if (!is_device_dma_coherent(dev))
 270                 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
 271 }
 272
 273 static void __swiotlb_sync_sg_for_cpu(struct device *dev,
 274                                       struct scatterlist *sgl, int nelems,
 275                                       enum dma_data_direction dir)
 276 {
 277         struct scatterlist *sg;
 278         int i;
 279
 280         if (!is_device_dma_coherent(dev))
 281                 for_each_sg(sgl, sg, nelems, i)
 282                         __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 283                                          sg->length, dir);
 284         swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
 285 }
 286
 287 static void __swiotlb_sync_sg_for_device(struct device *dev,
 288                                          struct scatterlist *sgl, int nelems,
 289                                          enum dma_data_direction dir)
 290 {
 291         struct scatterlist *sg;
 292         int i;
 293
 294         swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
 295         if (!is_device_dma_coherent(dev))
 296                 for_each_sg(sgl, sg, nelems, i)
 297                         __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
 298                                        sg->length, dir);
 299 }
 300
 301 /* vma->vm_page_prot must be set appropriately before calling this function */
 302 static int __dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 303                              void *cpu_addr, dma_addr_t dma_addr, size_t size)
 304 {
 305         int ret = -ENXIO;
 306         unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
 307                                         PAGE_SHIFT;
 308         unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 309         unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
 310         unsigned long off = vma->vm_pgoff;
 311
 312         if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 313                 return ret;
 314
 315         if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
 316                 ret = remap_pfn_range(vma, vma->vm_start,
 317                                       pfn + off,
 318                                       vma->vm_end - vma->vm_start,
 319                                       vma->vm_page_prot);
 320         }
 321
 322         return ret;
 323 }
 324
 325 static int __swiotlb_mmap(struct device *dev,
 326                           struct vm_area_struct *vma,
 327                           void *cpu_addr, dma_addr_t dma_addr, size_t size,
 328                           struct dma_attrs *attrs)
 329 {
 330         vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
 331                                              is_device_dma_coherent(dev));
 332         return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
 333 }
 334
 335 static struct dma_map_ops swiotlb_dma_ops = {
 336         .alloc = __dma_alloc,
 337         .free = __dma_free,
 338         .mmap = __swiotlb_mmap,
 339         .map_page = __swiotlb_map_page,
 340         .unmap_page = __swiotlb_unmap_page,
 341         .map_sg = __swiotlb_map_sg_attrs,
 342         .unmap_sg = __swiotlb_unmap_sg_attrs,
 343         .sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
 344         .sync_single_for_device = __swiotlb_sync_single_for_device,
 345         .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
 346         .sync_sg_for_device = __swiotlb_sync_sg_for_device,
 347         .dma_supported = swiotlb_dma_supported,
 348         .mapping_error = swiotlb_dma_mapping_error,
 349 };
 350
 351 extern int swiotlb_late_init_with_default_size(size_t default_size);
 352
 353 static int __init atomic_pool_init(void)
 354 {
 355         pgprot_t prot = __pgprot(PROT_NORMAL_NC);
 356         unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
 357         struct page *page;
 358         void *addr;
 359         unsigned int pool_size_order = get_order(atomic_pool_size);
 360
 361         if (dev_get_cma_area(NULL))
 362                 page = dma_alloc_from_contiguous(NULL, nr_pages,
 363                                                         pool_size_order);
 364         else
 365                 page = alloc_pages(GFP_DMA, pool_size_order);
 366
 367         if (page) {
 368                 int ret;
 369                 void *page_addr = page_address(page);
 370
 371                 memset(page_addr, 0, atomic_pool_size);
 372                 __dma_flush_range(page_addr, page_addr + atomic_pool_size);
 373
 374                 atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
 375                 if (!atomic_pool)
 376                         goto free_page;
 377
 378                 addr = dma_common_contiguous_remap(page, atomic_pool_size,
 379                                         VM_USERMAP, prot, atomic_pool_init);
 380
 381                 if (!addr)
 382                         goto destroy_genpool;
 383
 384                 ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
 385                                         page_to_phys(page),
 386                                         atomic_pool_size, -1);
 387                 if (ret)
 388                         goto remove_mapping;
 389
 390                 gen_pool_set_algo(atomic_pool,
 391                                   gen_pool_first_fit_order_align,
 392                                   (void *)PAGE_SHIFT);
 393
 394                 pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
 395                         atomic_pool_size / 1024);
 396                 return 0;
 397         }
 398         goto out;
 399
 400 remove_mapping:
 401         dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
 402 destroy_genpool:
 403         gen_pool_destroy(atomic_pool);
 404         atomic_pool = NULL;
 405 free_page:
 406         if (!dma_release_from_contiguous(NULL, page, nr_pages))
 407                 __free_pages(page, pool_size_order);
 408 out:
 409         pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
 410                 atomic_pool_size / 1024);
 411         return -ENOMEM;
 412 }
 413
 414 static int __init swiotlb_late_init(void)
 415 {
 416         size_t swiotlb_size = min(SZ_64M, MAX_ORDER_NR_PAGES << PAGE_SHIFT);
 417
 418         dma_ops = &swiotlb_dma_ops;
 419
 420         return swiotlb_late_init_with_default_size(swiotlb_size);
 421 }
 422
 423 static int __init arm64_dma_init(void)
 424 {
 425         int ret = 0;
 426
 427         ret |= swiotlb_late_init();
 428         ret |= atomic_pool_init();
 429
 430         return ret;
 431 }
 432 arch_initcall(arm64_dma_init);
 433
 434 #define PREALLOC_DMA_DEBUG_ENTRIES      4096
 435
 436 static int __init dma_debug_do_init(void)
 437 {
 438         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 439         return 0;
 440 }
 441 fs_initcall(dma_debug_do_init);