arch/mips/mm/dma-default.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2000  Ani Joshi <ajoshi@unixbox.com>
   7  * Copyright (C) 2000, 2001, 06  Ralf Baechle <ralf@linux-mips.org>
   8  * swiped from i386, and cloned for MIPS by Geert, polished by Ralf.
   9  */
  10
  11 #include <linux/types.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/mm.h>
  14 #include <linux/export.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/string.h>
  17 #include <linux/gfp.h>
  18 #include <linux/highmem.h>
  19 #include <linux/dma-contiguous.h>
  20
  21 #include <asm/cache.h>
  22 #include <asm/cpu-type.h>
  23 #include <asm/io.h>
  24
  25 #include <dma-coherence.h>
  26
  27 #if defined(CONFIG_DMA_MAYBE_COHERENT) && !defined(CONFIG_DMA_PERDEV_COHERENT)
  28 /* User defined DMA coherency from command line. */
  29 enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
  30 EXPORT_SYMBOL_GPL(coherentio);
  31 int hw_coherentio = 0;  /* Actual hardware supported DMA coherency setting. */
  32
  33 static int __init setcoherentio(char *str)
  34 {
  35         coherentio = IO_COHERENCE_ENABLED;
  36         pr_info("Hardware DMA cache coherency (command line)\n");
  37         return 0;
  38 }
  39 early_param("coherentio", setcoherentio);
  40
  41 static int __init setnocoherentio(char *str)
  42 {
  43         coherentio = IO_COHERENCE_DISABLED;
  44         pr_info("Software DMA cache coherency (command line)\n");
  45         return 0;
  46 }
  47 early_param("nocoherentio", setnocoherentio);
  48 #endif
  49
  50 static inline struct page *dma_addr_to_page(struct device *dev,
  51         dma_addr_t dma_addr)
  52 {
  53         return pfn_to_page(
  54                 plat_dma_addr_to_phys(dev, dma_addr) >> PAGE_SHIFT);
  55 }
  56
  57 /*
  58  * The affected CPUs below in 'cpu_needs_post_dma_flush()' can
  59  * speculatively fill random cachelines with stale data at any time,
  60  * requiring an extra flush post-DMA.
  61  *
  62  * Warning on the terminology - Linux calls an uncached area coherent;
  63  * MIPS terminology calls memory areas with hardware maintained coherency
  64  * coherent.
  65  *
  66  * Note that the R14000 and R16000 should also be checked for in this
  67  * condition.  However this function is only called on non-I/O-coherent
  68  * systems and only the R10000 and R12000 are used in such systems, the
  69  * SGI IP28 Indigo² rsp. SGI IP32 aka O2.
  70  */
  71 static inline bool cpu_needs_post_dma_flush(struct device *dev)
  72 {
  73         if (plat_device_is_coherent(dev))
  74                 return false;
  75
  76         switch (boot_cpu_type()) {
  77         case CPU_R10000:
  78         case CPU_R12000:
  79         case CPU_BMIPS5000:
  80                 return true;
  81
  82         default:
  83                 /*
  84                  * Presence of MAARs suggests that the CPU supports
  85                  * speculatively prefetching data, and therefore requires
  86                  * the post-DMA flush/invalidate.
  87                  */
  88                 return cpu_has_maar;
  89         }
  90 }
  91
  92 static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
  93 {
  94         gfp_t dma_flag;
  95
  96 #ifdef CONFIG_ISA
  97         if (dev == NULL)
  98                 dma_flag = __GFP_DMA;
  99         else
 100 #endif
 101 #if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
 102              if (dev == NULL || dev->coherent_dma_mask < DMA_BIT_MASK(32))
 103                         dma_flag = __GFP_DMA;
 104         else if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
 105                         dma_flag = __GFP_DMA32;
 106         else
 107 #endif
 108 #if defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_ZONE_DMA)
 109              if (dev == NULL || dev->coherent_dma_mask < DMA_BIT_MASK(64))
 110                 dma_flag = __GFP_DMA32;
 111         else
 112 #endif
 113 #if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
 114              if (dev == NULL ||
 115                  dev->coherent_dma_mask < DMA_BIT_MASK(sizeof(phys_addr_t) * 8))
 116                 dma_flag = __GFP_DMA;
 117         else
 118 #endif
 119                 dma_flag = 0;
 120
 121         /* Don't invoke OOM killer */
 122         gfp |= __GFP_NORETRY;
 123
 124         return gfp | dma_flag;
 125 }
 126
 127 static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
 128         dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 129 {
 130         void *ret;
 131         struct page *page = NULL;
 132         unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 133
 134         gfp = massage_gfp_flags(dev, gfp);
 135
 136         if (IS_ENABLED(CONFIG_DMA_CMA) && gfpflags_allow_blocking(gfp))
 137                 page = dma_alloc_from_contiguous(dev, count, get_order(size),
 138                                                  gfp);
 139         if (!page)
 140                 page = alloc_pages(gfp, get_order(size));
 141
 142         if (!page)
 143                 return NULL;
 144
 145         ret = page_address(page);
 146         memset(ret, 0, size);
 147         *dma_handle = plat_map_dma_mem(dev, ret, size);
 148         if (!(attrs & DMA_ATTR_NON_CONSISTENT) &&
 149             !plat_device_is_coherent(dev)) {
 150                 dma_cache_wback_inv((unsigned long) ret, size);
 151                 ret = UNCAC_ADDR(ret);
 152         }
 153
 154         return ret;
 155 }
 156
 157 static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 158         dma_addr_t dma_handle, unsigned long attrs)
 159 {
 160         unsigned long addr = (unsigned long) vaddr;
 161         unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 162         struct page *page = NULL;
 163
 164         plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
 165
 166         if (!(attrs & DMA_ATTR_NON_CONSISTENT) && !plat_device_is_coherent(dev))
 167                 addr = CAC_ADDR(addr);
 168
 169         page = virt_to_page((void *) addr);
 170
 171         if (!dma_release_from_contiguous(dev, page, count))
 172                 __free_pages(page, get_order(size));
 173 }
 174
 175 static int mips_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 176         void *cpu_addr, dma_addr_t dma_addr, size_t size,
 177         unsigned long attrs)
 178 {
 179         unsigned long user_count = vma_pages(vma);
 180         unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 181         unsigned long addr = (unsigned long)cpu_addr;
 182         unsigned long off = vma->vm_pgoff;
 183         unsigned long pfn;
 184         int ret = -ENXIO;
 185
 186         if (!plat_device_is_coherent(dev))
 187                 addr = CAC_ADDR(addr);
 188
 189         pfn = page_to_pfn(virt_to_page((void *)addr));
 190
 191         if (attrs & DMA_ATTR_WRITE_COMBINE)
 192                 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 193         else
 194                 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 195
 196         if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
 197                 return ret;
 198
 199         if (off < count && user_count <= (count - off)) {
 200                 ret = remap_pfn_range(vma, vma->vm_start,
 201                                       pfn + off,
 202                                       user_count << PAGE_SHIFT,
 203                                       vma->vm_page_prot);
 204         }
 205
 206         return ret;
 207 }
 208
 209 static inline void __dma_sync_virtual(void *addr, size_t size,
 210         enum dma_data_direction direction)
 211 {
 212         switch (direction) {
 213         case DMA_TO_DEVICE:
 214                 dma_cache_wback((unsigned long)addr, size);
 215                 break;
 216
 217         case DMA_FROM_DEVICE:
 218                 dma_cache_inv((unsigned long)addr, size);
 219                 break;
 220
 221         case DMA_BIDIRECTIONAL:
 222                 dma_cache_wback_inv((unsigned long)addr, size);
 223                 break;
 224
 225         default:
 226                 BUG();
 227         }
 228 }
 229
 230 /*
 231  * A single sg entry may refer to multiple physically contiguous
 232  * pages. But we still need to process highmem pages individually.
 233  * If highmem is not configured then the bulk of this loop gets
 234  * optimized out.
 235  */
 236 static inline void __dma_sync(struct page *page,
 237         unsigned long offset, size_t size, enum dma_data_direction direction)
 238 {
 239         size_t left = size;
 240
 241         do {
 242                 size_t len = left;
 243
 244                 if (PageHighMem(page)) {
 245                         void *addr;
 246
 247                         if (offset + len > PAGE_SIZE) {
 248                                 if (offset >= PAGE_SIZE) {
 249                                         page += offset >> PAGE_SHIFT;
 250                                         offset &= ~PAGE_MASK;
 251                                 }
 252                                 len = PAGE_SIZE - offset;
 253                         }
 254
 255                         addr = kmap_atomic(page);
 256                         __dma_sync_virtual(addr + offset, len, direction);
 257                         kunmap_atomic(addr);
 258                 } else
 259                         __dma_sync_virtual(page_address(page) + offset,
 260                                            size, direction);
 261                 offset = 0;
 262                 page++;
 263                 left -= len;
 264         } while (left);
 265 }
 266
 267 static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
 268         size_t size, enum dma_data_direction direction, unsigned long attrs)
 269 {
 270         if (cpu_needs_post_dma_flush(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 271                 __dma_sync(dma_addr_to_page(dev, dma_addr),
 272                            dma_addr & ~PAGE_MASK, size, direction);
 273         plat_post_dma_flush(dev);
 274         plat_unmap_dma_mem(dev, dma_addr, size, direction);
 275 }
 276
 277 static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 278         int nents, enum dma_data_direction direction, unsigned long attrs)
 279 {
 280         int i;
 281         struct scatterlist *sg;
 282
 283         for_each_sg(sglist, sg, nents, i) {
 284                 if (!plat_device_is_coherent(dev) &&
 285                     !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 286                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 287                                    direction);
 288 #ifdef CONFIG_NEED_SG_DMA_LENGTH
 289                 sg->dma_length = sg->length;
 290 #endif
 291                 sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) +
 292                                   sg->offset;
 293         }
 294
 295         return nents;
 296 }
 297
 298 static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
 299         unsigned long offset, size_t size, enum dma_data_direction direction,
 300         unsigned long attrs)
 301 {
 302         if (!plat_device_is_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 303                 __dma_sync(page, offset, size, direction);
 304
 305         return plat_map_dma_mem_page(dev, page) + offset;
 306 }
 307
 308 static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 309         int nhwentries, enum dma_data_direction direction,
 310         unsigned long attrs)
 311 {
 312         int i;
 313         struct scatterlist *sg;
 314
 315         for_each_sg(sglist, sg, nhwentries, i) {
 316                 if (!plat_device_is_coherent(dev) &&
 317                     !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
 318                     direction != DMA_TO_DEVICE)
 319                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 320                                    direction);
 321                 plat_unmap_dma_mem(dev, sg->dma_address, sg->length, direction);
 322         }
 323 }
 324
 325 static void mips_dma_sync_single_for_cpu(struct device *dev,
 326         dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 327 {
 328         if (cpu_needs_post_dma_flush(dev))
 329                 __dma_sync(dma_addr_to_page(dev, dma_handle),
 330                            dma_handle & ~PAGE_MASK, size, direction);
 331         plat_post_dma_flush(dev);
 332 }
 333
 334 static void mips_dma_sync_single_for_device(struct device *dev,
 335         dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 336 {
 337         if (!plat_device_is_coherent(dev))
 338                 __dma_sync(dma_addr_to_page(dev, dma_handle),
 339                            dma_handle & ~PAGE_MASK, size, direction);
 340 }
 341
 342 static void mips_dma_sync_sg_for_cpu(struct device *dev,
 343         struct scatterlist *sglist, int nelems,
 344         enum dma_data_direction direction)
 345 {
 346         int i;
 347         struct scatterlist *sg;
 348
 349         if (cpu_needs_post_dma_flush(dev)) {
 350                 for_each_sg(sglist, sg, nelems, i) {
 351                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 352                                    direction);
 353                 }
 354         }
 355         plat_post_dma_flush(dev);
 356 }
 357
 358 static void mips_dma_sync_sg_for_device(struct device *dev,
 359         struct scatterlist *sglist, int nelems,
 360         enum dma_data_direction direction)
 361 {
 362         int i;
 363         struct scatterlist *sg;
 364
 365         if (!plat_device_is_coherent(dev)) {
 366                 for_each_sg(sglist, sg, nelems, i) {
 367                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 368                                    direction);
 369                 }
 370         }
 371 }
 372
 373 static int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 374 {
 375         return 0;
 376 }
 377
 378 static int mips_dma_supported(struct device *dev, u64 mask)
 379 {
 380         return plat_dma_supported(dev, mask);
 381 }
 382
 383 static void mips_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 384                          enum dma_data_direction direction)
 385 {
 386         BUG_ON(direction == DMA_NONE);
 387
 388         if (!plat_device_is_coherent(dev))
 389                 __dma_sync_virtual(vaddr, size, direction);
 390 }
 391
 392 static const struct dma_map_ops mips_default_dma_map_ops = {
 393         .alloc = mips_dma_alloc_coherent,
 394         .free = mips_dma_free_coherent,
 395         .mmap = mips_dma_mmap,
 396         .map_page = mips_dma_map_page,
 397         .unmap_page = mips_dma_unmap_page,
 398         .map_sg = mips_dma_map_sg,
 399         .unmap_sg = mips_dma_unmap_sg,
 400         .sync_single_for_cpu = mips_dma_sync_single_for_cpu,
 401         .sync_single_for_device = mips_dma_sync_single_for_device,
 402         .sync_sg_for_cpu = mips_dma_sync_sg_for_cpu,
 403         .sync_sg_for_device = mips_dma_sync_sg_for_device,
 404         .mapping_error = mips_dma_mapping_error,
 405         .dma_supported = mips_dma_supported,
 406         .cache_sync = mips_dma_cache_sync,
 407 };
 408
 409 const struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
 410 EXPORT_SYMBOL(mips_dma_map_ops);
 411
 412 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 413
 414 static int __init mips_dma_init(void)
 415 {
 416         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 417
 418         return 0;
 419 }
 420 fs_initcall(mips_dma_init);