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/io.h>
  22
  23 #include <dma-coherence.h>
  24
  25 static inline struct page *dma_addr_to_page(struct device *dev,
  26         dma_addr_t dma_addr)
  27 {
  28         return pfn_to_page(
  29                 plat_dma_addr_to_phys(dev, dma_addr) >> PAGE_SHIFT);
  30 }
  31
  32 /*
  33  * Warning on the terminology - Linux calls an uncached area coherent;
  34  * MIPS terminology calls memory areas with hardware maintained coherency
  35  * coherent.
  36  */
  37
  38 static inline int cpu_is_noncoherent_r10000(struct device *dev)
  39 {
  40         return !plat_device_is_coherent(dev) &&
  41                (current_cpu_type() == CPU_R10000 ||
  42                current_cpu_type() == CPU_R12000);
  43 }
  44
  45 static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
  46 {
  47         gfp_t dma_flag;
  48
  49         /* ignore region specifiers */
  50         gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
  51
  52 #ifdef CONFIG_ISA
  53         if (dev == NULL)
  54                 dma_flag = __GFP_DMA;
  55         else
  56 #endif
  57 #if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
  58              if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
  59                         dma_flag = __GFP_DMA;
  60         else if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  61                         dma_flag = __GFP_DMA32;
  62         else
  63 #endif
  64 #if defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_ZONE_DMA)
  65              if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  66                 dma_flag = __GFP_DMA32;
  67         else
  68 #endif
  69 #if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
  70              if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
  71                 dma_flag = __GFP_DMA;
  72         else
  73 #endif
  74                 dma_flag = 0;
  75
  76         /* Don't invoke OOM killer */
  77         gfp |= __GFP_NORETRY;
  78
  79         return gfp | dma_flag;
  80 }
  81
  82 void *dma_alloc_noncoherent(struct device *dev, size_t size,
  83         dma_addr_t * dma_handle, gfp_t gfp)
  84 {
  85         void *ret;
  86
  87         gfp = massage_gfp_flags(dev, gfp);
  88
  89         ret = (void *) __get_free_pages(gfp, get_order(size));
  90
  91         if (ret != NULL) {
  92                 memset(ret, 0, size);
  93                 *dma_handle = plat_map_dma_mem(dev, ret, size);
  94         }
  95
  96         return ret;
  97 }
  98 EXPORT_SYMBOL(dma_alloc_noncoherent);
  99
 100 static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
 101         dma_addr_t * dma_handle, gfp_t gfp)
 102 {
 103         void *ret;
 104
 105         if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
 106                 return ret;
 107
 108         gfp = massage_gfp_flags(dev, gfp);
 109
 110         ret = (void *) __get_free_pages(gfp, get_order(size));
 111
 112         if (ret) {
 113                 memset(ret, 0, size);
 114                 *dma_handle = plat_map_dma_mem(dev, ret, size);
 115
 116                 if (!plat_device_is_coherent(dev)) {
 117                         dma_cache_wback_inv((unsigned long) ret, size);
 118                         ret = UNCAC_ADDR(ret);
 119                 }
 120         }
 121
 122         return ret;
 123 }
 124
 125
 126 void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 127         dma_addr_t dma_handle)
 128 {
 129         plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
 130         free_pages((unsigned long) vaddr, get_order(size));
 131 }
 132 EXPORT_SYMBOL(dma_free_noncoherent);
 133
 134 static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 135         dma_addr_t dma_handle)
 136 {
 137         unsigned long addr = (unsigned long) vaddr;
 138         int order = get_order(size);
 139
 140         if (dma_release_from_coherent(dev, order, vaddr))
 141                 return;
 142
 143         plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
 144
 145         if (!plat_device_is_coherent(dev))
 146                 addr = CAC_ADDR(addr);
 147
 148         free_pages(addr, get_order(size));
 149 }
 150
 151 static inline void __dma_sync_virtual(void *addr, size_t size,
 152         enum dma_data_direction direction)
 153 {
 154         switch (direction) {
 155         case DMA_TO_DEVICE:
 156                 dma_cache_wback((unsigned long)addr, size);
 157                 break;
 158
 159         case DMA_FROM_DEVICE:
 160                 dma_cache_inv((unsigned long)addr, size);
 161                 break;
 162
 163         case DMA_BIDIRECTIONAL:
 164                 dma_cache_wback_inv((unsigned long)addr, size);
 165                 break;
 166
 167         default:
 168                 BUG();
 169         }
 170 }
 171
 172 /*
 173  * A single sg entry may refer to multiple physically contiguous
 174  * pages. But we still need to process highmem pages individually.
 175  * If highmem is not configured then the bulk of this loop gets
 176  * optimized out.
 177  */
 178 static inline void __dma_sync(struct page *page,
 179         unsigned long offset, size_t size, enum dma_data_direction direction)
 180 {
 181         size_t left = size;
 182
 183         do {
 184                 size_t len = left;
 185
 186                 if (PageHighMem(page)) {
 187                         void *addr;
 188
 189                         if (offset + len > PAGE_SIZE) {
 190                                 if (offset >= PAGE_SIZE) {
 191                                         page += offset >> PAGE_SHIFT;
 192                                         offset &= ~PAGE_MASK;
 193                                 }
 194                                 len = PAGE_SIZE - offset;
 195                         }
 196
 197                         addr = kmap_atomic(page);
 198                         __dma_sync_virtual(addr + offset, len, direction);
 199                         kunmap_atomic(addr);
 200                 } else
 201                         __dma_sync_virtual(page_address(page) + offset,
 202                                            size, direction);
 203                 offset = 0;
 204                 page++;
 205                 left -= len;
 206         } while (left);
 207 }
 208
 209 static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
 210         size_t size, enum dma_data_direction direction, struct dma_attrs *attrs)
 211 {
 212         if (cpu_is_noncoherent_r10000(dev))
 213                 __dma_sync(dma_addr_to_page(dev, dma_addr),
 214                            dma_addr & ~PAGE_MASK, size, direction);
 215
 216         plat_unmap_dma_mem(dev, dma_addr, size, direction);
 217 }
 218
 219 static int mips_dma_map_sg(struct device *dev, struct scatterlist *sg,
 220         int nents, enum dma_data_direction direction, struct dma_attrs *attrs)
 221 {
 222         int i;
 223
 224         for (i = 0; i < nents; i++, sg++) {
 225                 if (!plat_device_is_coherent(dev))
 226                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 227                                    direction);
 228                 sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) +
 229                                   sg->offset;
 230         }
 231
 232         return nents;
 233 }
 234
 235 static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
 236         unsigned long offset, size_t size, enum dma_data_direction direction,
 237         struct dma_attrs *attrs)
 238 {
 239         if (!plat_device_is_coherent(dev))
 240                 __dma_sync(page, offset, size, direction);
 241
 242         return plat_map_dma_mem_page(dev, page) + offset;
 243 }
 244
 245 static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 246         int nhwentries, enum dma_data_direction direction,
 247         struct dma_attrs *attrs)
 248 {
 249         int i;
 250
 251         for (i = 0; i < nhwentries; i++, sg++) {
 252                 if (!plat_device_is_coherent(dev) &&
 253                     direction != DMA_TO_DEVICE)
 254                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 255                                    direction);
 256                 plat_unmap_dma_mem(dev, sg->dma_address, sg->length, direction);
 257         }
 258 }
 259
 260 static void mips_dma_sync_single_for_cpu(struct device *dev,
 261         dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 262 {
 263         if (cpu_is_noncoherent_r10000(dev))
 264                 __dma_sync(dma_addr_to_page(dev, dma_handle),
 265                            dma_handle & ~PAGE_MASK, size, direction);
 266 }
 267
 268 static void mips_dma_sync_single_for_device(struct device *dev,
 269         dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 270 {
 271         plat_extra_sync_for_device(dev);
 272         if (!plat_device_is_coherent(dev))
 273                 __dma_sync(dma_addr_to_page(dev, dma_handle),
 274                            dma_handle & ~PAGE_MASK, size, direction);
 275 }
 276
 277 static void mips_dma_sync_sg_for_cpu(struct device *dev,
 278         struct scatterlist *sg, int nelems, enum dma_data_direction direction)
 279 {
 280         int i;
 281
 282         /* Make sure that gcc doesn't leave the empty loop body.  */
 283         for (i = 0; i < nelems; i++, sg++) {
 284                 if (cpu_is_noncoherent_r10000(dev))
 285                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 286                                    direction);
 287         }
 288 }
 289
 290 static void mips_dma_sync_sg_for_device(struct device *dev,
 291         struct scatterlist *sg, int nelems, enum dma_data_direction direction)
 292 {
 293         int i;
 294
 295         /* Make sure that gcc doesn't leave the empty loop body.  */
 296         for (i = 0; i < nelems; i++, sg++) {
 297                 if (!plat_device_is_coherent(dev))
 298                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 299                                    direction);
 300         }
 301 }
 302
 303 int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 304 {
 305         return plat_dma_mapping_error(dev, dma_addr);
 306 }
 307
 308 int mips_dma_supported(struct device *dev, u64 mask)
 309 {
 310         return plat_dma_supported(dev, mask);
 311 }
 312
 313 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 314                          enum dma_data_direction direction)
 315 {
 316         BUG_ON(direction == DMA_NONE);
 317
 318         plat_extra_sync_for_device(dev);
 319         if (!plat_device_is_coherent(dev))
 320                 __dma_sync_virtual(vaddr, size, direction);
 321 }
 322
 323 EXPORT_SYMBOL(dma_cache_sync);
 324
 325 static struct dma_map_ops mips_default_dma_map_ops = {
 326         .alloc_coherent = mips_dma_alloc_coherent,
 327         .free_coherent = mips_dma_free_coherent,
 328         .map_page = mips_dma_map_page,
 329         .unmap_page = mips_dma_unmap_page,
 330         .map_sg = mips_dma_map_sg,
 331         .unmap_sg = mips_dma_unmap_sg,
 332         .sync_single_for_cpu = mips_dma_sync_single_for_cpu,
 333         .sync_single_for_device = mips_dma_sync_single_for_device,
 334         .sync_sg_for_cpu = mips_dma_sync_sg_for_cpu,
 335         .sync_sg_for_device = mips_dma_sync_sg_for_device,
 336         .mapping_error = mips_dma_mapping_error,
 337         .dma_supported = mips_dma_supported
 338 };
 339
 340 struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
 341 EXPORT_SYMBOL(mips_dma_map_ops);
 342
 343 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 344
 345 static int __init mips_dma_init(void)
 346 {
 347         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 348
 349         return 0;
 350 }
 351 fs_initcall(mips_dma_init);