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/module.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/string.h>
  17 #include <linux/gfp.h>
  18 #include <linux/highmem.h>
  19
  20 #include <asm/cache.h>
  21 #include <asm/cpu-type.h>
  22 #include <asm/io.h>
  23
  24 #include <dma-coherence.h>
  25
  26 int coherentio = 0;     /* User defined DMA coherency from command line. */
  27 EXPORT_SYMBOL_GPL(coherentio);
  28 int hw_coherentio = 0;  /* Actual hardware supported DMA coherency setting. */
  29
  30 static int __init setcoherentio(char *str)
  31 {
  32         coherentio = 1;
  33         pr_info("Hardware DMA cache coherency (command line)\n");
  34         return 0;
  35 }
  36 early_param("coherentio", setcoherentio);
  37
  38 static int __init setnocoherentio(char *str)
  39 {
  40         coherentio = 0;
  41         pr_info("Software DMA cache coherency (command line)\n");
  42         return 0;
  43 }
  44 early_param("nocoherentio", setnocoherentio);
  45
  46 static inline struct page *dma_addr_to_page(struct device *dev,
  47         dma_addr_t dma_addr)
  48 {
  49         return pfn_to_page(
  50                 plat_dma_addr_to_phys(dev, dma_addr) >> PAGE_SHIFT);
  51 }
  52
  53 /*
  54  * The affected CPUs below in 'cpu_needs_post_dma_flush()' can
  55  * speculatively fill random cachelines with stale data at any time,
  56  * requiring an extra flush post-DMA.
  57  *
  58  * Warning on the terminology - Linux calls an uncached area coherent;
  59  * MIPS terminology calls memory areas with hardware maintained coherency
  60  * coherent.
  61  */
  62 static inline int cpu_needs_post_dma_flush(struct device *dev)
  63 {
  64         return !plat_device_is_coherent(dev) &&
  65                (boot_cpu_type() == CPU_R10000 ||
  66                 boot_cpu_type() == CPU_R12000 ||
  67                 boot_cpu_type() == CPU_BMIPS5000);
  68 }
  69
  70 static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
  71 {
  72         gfp_t dma_flag;
  73
  74         /* ignore region specifiers */
  75         gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
  76
  77 #ifdef CONFIG_ISA
  78         if (dev == NULL)
  79                 dma_flag = __GFP_DMA;
  80         else
  81 #endif
  82 #if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
  83              if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
  84                         dma_flag = __GFP_DMA;
  85         else if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  86                         dma_flag = __GFP_DMA32;
  87         else
  88 #endif
  89 #if defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_ZONE_DMA)
  90              if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  91                 dma_flag = __GFP_DMA32;
  92         else
  93 #endif
  94 #if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
  95              if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  96                 dma_flag = __GFP_DMA;
  97         else
  98 #endif
  99                 dma_flag = 0;
 100
 101         /* Don't invoke OOM killer */
 102         gfp |= __GFP_NORETRY;
 103
 104         return gfp | dma_flag;
 105 }
 106
 107 void *dma_alloc_noncoherent(struct device *dev, size_t size,
 108         dma_addr_t * dma_handle, gfp_t gfp)
 109 {
 110         void *ret;
 111
 112         gfp = massage_gfp_flags(dev, gfp);
 113
 114         ret = (void *) __get_free_pages(gfp, get_order(size));
 115
 116         if (ret != NULL) {
 117                 memset(ret, 0, size);
 118                 *dma_handle = plat_map_dma_mem(dev, ret, size);
 119         }
 120
 121         return ret;
 122 }
 123 EXPORT_SYMBOL(dma_alloc_noncoherent);
 124
 125 static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
 126         dma_addr_t * dma_handle, gfp_t gfp, struct dma_attrs *attrs)
 127 {
 128         void *ret;
 129
 130         if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
 131                 return ret;
 132
 133         gfp = massage_gfp_flags(dev, gfp);
 134
 135         ret = (void *) __get_free_pages(gfp, get_order(size));
 136
 137         if (ret) {
 138                 memset(ret, 0, size);
 139                 *dma_handle = plat_map_dma_mem(dev, ret, size);
 140
 141                 if (!plat_device_is_coherent(dev)) {
 142                         dma_cache_wback_inv((unsigned long) ret, size);
 143                         if (!hw_coherentio)
 144                                 ret = UNCAC_ADDR(ret);
 145                 }
 146         }
 147
 148         return ret;
 149 }
 150
 151
 152 void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 153         dma_addr_t dma_handle)
 154 {
 155         plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
 156         free_pages((unsigned long) vaddr, get_order(size));
 157 }
 158 EXPORT_SYMBOL(dma_free_noncoherent);
 159
 160 static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 161         dma_addr_t dma_handle, struct dma_attrs *attrs)
 162 {
 163         unsigned long addr = (unsigned long) vaddr;
 164         int order = get_order(size);
 165
 166         if (dma_release_from_coherent(dev, order, vaddr))
 167                 return;
 168
 169         plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
 170
 171         if (!plat_device_is_coherent(dev) && !hw_coherentio)
 172                 addr = CAC_ADDR(addr);
 173
 174         free_pages(addr, get_order(size));
 175 }
 176
 177 static inline void __dma_sync_virtual(void *addr, size_t size,
 178         enum dma_data_direction direction)
 179 {
 180         switch (direction) {
 181         case DMA_TO_DEVICE:
 182                 dma_cache_wback((unsigned long)addr, size);
 183                 break;
 184
 185         case DMA_FROM_DEVICE:
 186                 dma_cache_inv((unsigned long)addr, size);
 187                 break;
 188
 189         case DMA_BIDIRECTIONAL:
 190                 dma_cache_wback_inv((unsigned long)addr, size);
 191                 break;
 192
 193         default:
 194                 BUG();
 195         }
 196 }
 197
 198 /*
 199  * A single sg entry may refer to multiple physically contiguous
 200  * pages. But we still need to process highmem pages individually.
 201  * If highmem is not configured then the bulk of this loop gets
 202  * optimized out.
 203  */
 204 static inline void __dma_sync(struct page *page,
 205         unsigned long offset, size_t size, enum dma_data_direction direction)
 206 {
 207         size_t left = size;
 208
 209         do {
 210                 size_t len = left;
 211
 212                 if (PageHighMem(page)) {
 213                         void *addr;
 214
 215                         if (offset + len > PAGE_SIZE) {
 216                                 if (offset >= PAGE_SIZE) {
 217                                         page += offset >> PAGE_SHIFT;
 218                                         offset &= ~PAGE_MASK;
 219                                 }
 220                                 len = PAGE_SIZE - offset;
 221                         }
 222
 223                         addr = kmap_atomic(page);
 224                         __dma_sync_virtual(addr + offset, len, direction);
 225                         kunmap_atomic(addr);
 226                 } else
 227                         __dma_sync_virtual(page_address(page) + offset,
 228                                            size, direction);
 229                 offset = 0;
 230                 page++;
 231                 left -= len;
 232         } while (left);
 233 }
 234
 235 static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
 236         size_t size, enum dma_data_direction direction, struct dma_attrs *attrs)
 237 {
 238         if (cpu_needs_post_dma_flush(dev))
 239                 __dma_sync(dma_addr_to_page(dev, dma_addr),
 240                            dma_addr & ~PAGE_MASK, size, direction);
 241
 242         plat_unmap_dma_mem(dev, dma_addr, size, direction);
 243 }
 244
 245 static int mips_dma_map_sg(struct device *dev, struct scatterlist *sg,
 246         int nents, enum dma_data_direction direction, struct dma_attrs *attrs)
 247 {
 248         int i;
 249
 250         for (i = 0; i < nents; i++, sg++) {
 251                 if (!plat_device_is_coherent(dev))
 252                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 253                                    direction);
 254 #ifdef CONFIG_NEED_SG_DMA_LENGTH
 255                 sg->dma_length = sg->length;
 256 #endif
 257                 sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) +
 258                                   sg->offset;
 259         }
 260
 261         return nents;
 262 }
 263
 264 static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
 265         unsigned long offset, size_t size, enum dma_data_direction direction,
 266         struct dma_attrs *attrs)
 267 {
 268         if (!plat_device_is_coherent(dev))
 269                 __dma_sync(page, offset, size, direction);
 270
 271         return plat_map_dma_mem_page(dev, page) + offset;
 272 }
 273
 274 static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 275         int nhwentries, enum dma_data_direction direction,
 276         struct dma_attrs *attrs)
 277 {
 278         int i;
 279
 280         for (i = 0; i < nhwentries; i++, sg++) {
 281                 if (!plat_device_is_coherent(dev) &&
 282                     direction != DMA_TO_DEVICE)
 283                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 284                                    direction);
 285                 plat_unmap_dma_mem(dev, sg->dma_address, sg->length, direction);
 286         }
 287 }
 288
 289 static void mips_dma_sync_single_for_cpu(struct device *dev,
 290         dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 291 {
 292         if (cpu_needs_post_dma_flush(dev))
 293                 __dma_sync(dma_addr_to_page(dev, dma_handle),
 294                            dma_handle & ~PAGE_MASK, size, direction);
 295 }
 296
 297 static void mips_dma_sync_single_for_device(struct device *dev,
 298         dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 299 {
 300         plat_extra_sync_for_device(dev);
 301         if (!plat_device_is_coherent(dev))
 302                 __dma_sync(dma_addr_to_page(dev, dma_handle),
 303                            dma_handle & ~PAGE_MASK, size, direction);
 304 }
 305
 306 static void mips_dma_sync_sg_for_cpu(struct device *dev,
 307         struct scatterlist *sg, int nelems, enum dma_data_direction direction)
 308 {
 309         int i;
 310
 311         /* Make sure that gcc doesn't leave the empty loop body.  */
 312         for (i = 0; i < nelems; i++, sg++) {
 313                 if (cpu_needs_post_dma_flush(dev))
 314                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 315                                    direction);
 316         }
 317 }
 318
 319 static void mips_dma_sync_sg_for_device(struct device *dev,
 320         struct scatterlist *sg, int nelems, enum dma_data_direction direction)
 321 {
 322         int i;
 323
 324         /* Make sure that gcc doesn't leave the empty loop body.  */
 325         for (i = 0; i < nelems; i++, sg++) {
 326                 if (!plat_device_is_coherent(dev))
 327                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 328                                    direction);
 329         }
 330 }
 331
 332 int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 333 {
 334         return plat_dma_mapping_error(dev, dma_addr);
 335 }
 336
 337 int mips_dma_supported(struct device *dev, u64 mask)
 338 {
 339         return plat_dma_supported(dev, mask);
 340 }
 341
 342 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 343                          enum dma_data_direction direction)
 344 {
 345         BUG_ON(direction == DMA_NONE);
 346
 347         plat_extra_sync_for_device(dev);
 348         if (!plat_device_is_coherent(dev))
 349                 __dma_sync_virtual(vaddr, size, direction);
 350 }
 351
 352 EXPORT_SYMBOL(dma_cache_sync);
 353
 354 static struct dma_map_ops mips_default_dma_map_ops = {
 355         .alloc = mips_dma_alloc_coherent,
 356         .free = mips_dma_free_coherent,
 357         .map_page = mips_dma_map_page,
 358         .unmap_page = mips_dma_unmap_page,
 359         .map_sg = mips_dma_map_sg,
 360         .unmap_sg = mips_dma_unmap_sg,
 361         .sync_single_for_cpu = mips_dma_sync_single_for_cpu,
 362         .sync_single_for_device = mips_dma_sync_single_for_device,
 363         .sync_sg_for_cpu = mips_dma_sync_sg_for_cpu,
 364         .sync_sg_for_device = mips_dma_sync_sg_for_device,
 365         .mapping_error = mips_dma_mapping_error,
 366         .dma_supported = mips_dma_supported
 367 };
 368
 369 struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
 370 EXPORT_SYMBOL(mips_dma_map_ops);
 371
 372 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 373
 374 static int __init mips_dma_init(void)
 375 {
 376         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 377
 378         return 0;
 379 }
 380 fs_initcall(mips_dma_init);