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 == NULL || 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 == NULL || 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 == NULL ||
 104                  dev->coherent_dma_mask < DMA_BIT_MASK(sizeof(phys_addr_t) * 8))
 105                 dma_flag = __GFP_DMA;
 106         else
 107 #endif
 108                 dma_flag = 0;
 109
 110         /* Don't invoke OOM killer */
 111         gfp |= __GFP_NORETRY;
 112
 113         return gfp | dma_flag;
 114 }
 115
 116 static void *mips_dma_alloc_noncoherent(struct device *dev, size_t size,
 117         dma_addr_t * dma_handle, gfp_t gfp)
 118 {
 119         void *ret;
 120
 121         gfp = massage_gfp_flags(dev, gfp);
 122
 123         ret = (void *) __get_free_pages(gfp, get_order(size));
 124
 125         if (ret != NULL) {
 126                 memset(ret, 0, size);
 127                 *dma_handle = plat_map_dma_mem(dev, ret, size);
 128         }
 129
 130         return ret;
 131 }
 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         /*
 141          * XXX: seems like the coherent and non-coherent implementations could
 142          * be consolidated.
 143          */
 144         if (dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs))
 145                 return mips_dma_alloc_noncoherent(dev, size, dma_handle, gfp);
 146
 147         gfp = massage_gfp_flags(dev, gfp);
 148
 149         if (IS_ENABLED(CONFIG_DMA_CMA) && gfpflags_allow_blocking(gfp))
 150                 page = dma_alloc_from_contiguous(dev,
 151                                         count, get_order(size));
 152         if (!page)
 153                 page = alloc_pages(gfp, get_order(size));
 154
 155         if (!page)
 156                 return NULL;
 157
 158         ret = page_address(page);
 159         memset(ret, 0, size);
 160         *dma_handle = plat_map_dma_mem(dev, ret, size);
 161         if (!plat_device_is_coherent(dev)) {
 162                 dma_cache_wback_inv((unsigned long) ret, size);
 163                 if (!hw_coherentio)
 164                         ret = UNCAC_ADDR(ret);
 165         }
 166
 167         return ret;
 168 }
 169
 170
 171 static void mips_dma_free_noncoherent(struct device *dev, size_t size,
 172                 void *vaddr, dma_addr_t dma_handle)
 173 {
 174         plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
 175         free_pages((unsigned long) vaddr, get_order(size));
 176 }
 177
 178 static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 179         dma_addr_t dma_handle, struct dma_attrs *attrs)
 180 {
 181         unsigned long addr = (unsigned long) vaddr;
 182         unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 183         struct page *page = NULL;
 184
 185         if (dma_get_attr(DMA_ATTR_NON_CONSISTENT, attrs)) {
 186                 mips_dma_free_noncoherent(dev, size, vaddr, dma_handle);
 187                 return;
 188         }
 189
 190         plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
 191
 192         if (!plat_device_is_coherent(dev) && !hw_coherentio)
 193                 addr = CAC_ADDR(addr);
 194
 195         page = virt_to_page((void *) addr);
 196
 197         if (!dma_release_from_contiguous(dev, page, count))
 198                 __free_pages(page, get_order(size));
 199 }
 200
 201 static int mips_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 202         void *cpu_addr, dma_addr_t dma_addr, size_t size,
 203         struct dma_attrs *attrs)
 204 {
 205         unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 206         unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 207         unsigned long addr = (unsigned long)cpu_addr;
 208         unsigned long off = vma->vm_pgoff;
 209         unsigned long pfn;
 210         int ret = -ENXIO;
 211
 212         if (!plat_device_is_coherent(dev) && !hw_coherentio)
 213                 addr = CAC_ADDR(addr);
 214
 215         pfn = page_to_pfn(virt_to_page((void *)addr));
 216
 217         if (dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
 218                 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 219         else
 220                 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 221
 222         if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 223                 return ret;
 224
 225         if (off < count && user_count <= (count - off)) {
 226                 ret = remap_pfn_range(vma, vma->vm_start,
 227                                       pfn + off,
 228                                       user_count << PAGE_SHIFT,
 229                                       vma->vm_page_prot);
 230         }
 231
 232         return ret;
 233 }
 234
 235 static inline void __dma_sync_virtual(void *addr, size_t size,
 236         enum dma_data_direction direction)
 237 {
 238         switch (direction) {
 239         case DMA_TO_DEVICE:
 240                 dma_cache_wback((unsigned long)addr, size);
 241                 break;
 242
 243         case DMA_FROM_DEVICE:
 244                 dma_cache_inv((unsigned long)addr, size);
 245                 break;
 246
 247         case DMA_BIDIRECTIONAL:
 248                 dma_cache_wback_inv((unsigned long)addr, size);
 249                 break;
 250
 251         default:
 252                 BUG();
 253         }
 254 }
 255
 256 /*
 257  * A single sg entry may refer to multiple physically contiguous
 258  * pages. But we still need to process highmem pages individually.
 259  * If highmem is not configured then the bulk of this loop gets
 260  * optimized out.
 261  */
 262 static inline void __dma_sync(struct page *page,
 263         unsigned long offset, size_t size, enum dma_data_direction direction)
 264 {
 265         size_t left = size;
 266
 267         do {
 268                 size_t len = left;
 269
 270                 if (PageHighMem(page)) {
 271                         void *addr;
 272
 273                         if (offset + len > PAGE_SIZE) {
 274                                 if (offset >= PAGE_SIZE) {
 275                                         page += offset >> PAGE_SHIFT;
 276                                         offset &= ~PAGE_MASK;
 277                                 }
 278                                 len = PAGE_SIZE - offset;
 279                         }
 280
 281                         addr = kmap_atomic(page);
 282                         __dma_sync_virtual(addr + offset, len, direction);
 283                         kunmap_atomic(addr);
 284                 } else
 285                         __dma_sync_virtual(page_address(page) + offset,
 286                                            size, direction);
 287                 offset = 0;
 288                 page++;
 289                 left -= len;
 290         } while (left);
 291 }
 292
 293 static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
 294         size_t size, enum dma_data_direction direction, struct dma_attrs *attrs)
 295 {
 296         if (cpu_needs_post_dma_flush(dev))
 297                 __dma_sync(dma_addr_to_page(dev, dma_addr),
 298                            dma_addr & ~PAGE_MASK, size, direction);
 299         plat_post_dma_flush(dev);
 300         plat_unmap_dma_mem(dev, dma_addr, size, direction);
 301 }
 302
 303 static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 304         int nents, enum dma_data_direction direction, struct dma_attrs *attrs)
 305 {
 306         int i;
 307         struct scatterlist *sg;
 308
 309         for_each_sg(sglist, sg, nents, i) {
 310                 if (!plat_device_is_coherent(dev))
 311                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 312                                    direction);
 313 #ifdef CONFIG_NEED_SG_DMA_LENGTH
 314                 sg->dma_length = sg->length;
 315 #endif
 316                 sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) +
 317                                   sg->offset;
 318         }
 319
 320         return nents;
 321 }
 322
 323 static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
 324         unsigned long offset, size_t size, enum dma_data_direction direction,
 325         struct dma_attrs *attrs)
 326 {
 327         if (!plat_device_is_coherent(dev))
 328                 __dma_sync(page, offset, size, direction);
 329
 330         return plat_map_dma_mem_page(dev, page) + offset;
 331 }
 332
 333 static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 334         int nhwentries, enum dma_data_direction direction,
 335         struct dma_attrs *attrs)
 336 {
 337         int i;
 338         struct scatterlist *sg;
 339
 340         for_each_sg(sglist, sg, nhwentries, i) {
 341                 if (!plat_device_is_coherent(dev) &&
 342                     direction != DMA_TO_DEVICE)
 343                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 344                                    direction);
 345                 plat_unmap_dma_mem(dev, sg->dma_address, sg->length, direction);
 346         }
 347 }
 348
 349 static void mips_dma_sync_single_for_cpu(struct device *dev,
 350         dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 351 {
 352         if (cpu_needs_post_dma_flush(dev))
 353                 __dma_sync(dma_addr_to_page(dev, dma_handle),
 354                            dma_handle & ~PAGE_MASK, size, direction);
 355         plat_post_dma_flush(dev);
 356 }
 357
 358 static void mips_dma_sync_single_for_device(struct device *dev,
 359         dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
 360 {
 361         if (!plat_device_is_coherent(dev))
 362                 __dma_sync(dma_addr_to_page(dev, dma_handle),
 363                            dma_handle & ~PAGE_MASK, size, direction);
 364 }
 365
 366 static void mips_dma_sync_sg_for_cpu(struct device *dev,
 367         struct scatterlist *sglist, int nelems,
 368         enum dma_data_direction direction)
 369 {
 370         int i;
 371         struct scatterlist *sg;
 372
 373         if (cpu_needs_post_dma_flush(dev)) {
 374                 for_each_sg(sglist, sg, nelems, i) {
 375                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 376                                    direction);
 377                 }
 378         }
 379         plat_post_dma_flush(dev);
 380 }
 381
 382 static void mips_dma_sync_sg_for_device(struct device *dev,
 383         struct scatterlist *sglist, int nelems,
 384         enum dma_data_direction direction)
 385 {
 386         int i;
 387         struct scatterlist *sg;
 388
 389         if (!plat_device_is_coherent(dev)) {
 390                 for_each_sg(sglist, sg, nelems, i) {
 391                         __dma_sync(sg_page(sg), sg->offset, sg->length,
 392                                    direction);
 393                 }
 394         }
 395 }
 396
 397 int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 398 {
 399         return 0;
 400 }
 401
 402 int mips_dma_supported(struct device *dev, u64 mask)
 403 {
 404         return plat_dma_supported(dev, mask);
 405 }
 406
 407 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 408                          enum dma_data_direction direction)
 409 {
 410         BUG_ON(direction == DMA_NONE);
 411
 412         if (!plat_device_is_coherent(dev))
 413                 __dma_sync_virtual(vaddr, size, direction);
 414 }
 415
 416 EXPORT_SYMBOL(dma_cache_sync);
 417
 418 static struct dma_map_ops mips_default_dma_map_ops = {
 419         .alloc = mips_dma_alloc_coherent,
 420         .free = mips_dma_free_coherent,
 421         .mmap = mips_dma_mmap,
 422         .map_page = mips_dma_map_page,
 423         .unmap_page = mips_dma_unmap_page,
 424         .map_sg = mips_dma_map_sg,
 425         .unmap_sg = mips_dma_unmap_sg,
 426         .sync_single_for_cpu = mips_dma_sync_single_for_cpu,
 427         .sync_single_for_device = mips_dma_sync_single_for_device,
 428         .sync_sg_for_cpu = mips_dma_sync_sg_for_cpu,
 429         .sync_sg_for_device = mips_dma_sync_sg_for_device,
 430         .mapping_error = mips_dma_mapping_error,
 431         .dma_supported = mips_dma_supported
 432 };
 433
 434 struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
 435 EXPORT_SYMBOL(mips_dma_map_ops);
 436
 437 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
 438
 439 static int __init mips_dma_init(void)
 440 {
 441         dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 442
 443         return 0;
 444 }
 445 fs_initcall(mips_dma_init);