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