arch/i386/kernel/pci-dma-xen.c

   1 /*
   2  * Dynamic DMA mapping support.
   3  *
   4  * On i386 there is no hardware dynamic DMA address translation,
   5  * so consistent alloc/free are merely page allocation/freeing.
   6  * The rest of the dynamic DMA mapping interface is implemented
   7  * in asm/pci.h.
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/mm.h>
  12 #include <linux/string.h>
  13 #include <linux/pci.h>
  14 #include <linux/module.h>
  15 #include <linux/version.h>
  16 #include <asm/io.h>
  17 #include <xen/balloon.h>
  18 #include <asm/tlbflush.h>
  19 #include <asm-i386/mach-xen/asm/swiotlb.h>
  20 #include <asm/bug.h>
  21
  22 #ifdef __x86_64__
  23 int iommu_merge __read_mostly = 0;
  24 EXPORT_SYMBOL(iommu_merge);
  25
  26 dma_addr_t bad_dma_address __read_mostly;
  27 EXPORT_SYMBOL(bad_dma_address);
  28
  29 /* This tells the BIO block layer to assume merging. Default to off
  30    because we cannot guarantee merging later. */
  31 int iommu_bio_merge __read_mostly = 0;
  32 EXPORT_SYMBOL(iommu_bio_merge);
  33
  34 __init int iommu_setup(char *p)
  35 {
  36     return 1;
  37 }
  38 #endif
  39
  40 struct dma_coherent_mem {
  41         void            *virt_base;
  42         u32             device_base;
  43         int             size;
  44         int             flags;
  45         unsigned long   *bitmap;
  46 };
  47
  48 #define IOMMU_BUG_ON(test)                              \
  49 do {                                                    \
  50         if (unlikely(test)) {                           \
  51                 printk(KERN_ALERT "Fatal DMA error! "   \
  52                        "Please use 'swiotlb=force'\n"); \
  53                 BUG();                                  \
  54         }                                               \
  55 } while (0)
  56
  57 int
  58 dma_map_sg(struct device *hwdev, struct scatterlist *sg, int nents,
  59            enum dma_data_direction direction)
  60 {
  61         int i, rc;
  62
  63         if (direction == DMA_NONE)
  64                 BUG();
  65         WARN_ON(nents == 0 || sg[0].length == 0);
  66
  67         if (swiotlb) {
  68                 rc = swiotlb_map_sg(hwdev, sg, nents, direction);
  69         } else {
  70                 for (i = 0; i < nents; i++ ) {
  71                         sg[i].dma_address =
  72                                 page_to_bus(sg[i].page) + sg[i].offset;
  73                         sg[i].dma_length  = sg[i].length;
  74                         BUG_ON(!sg[i].page);
  75                         IOMMU_BUG_ON(address_needs_mapping(
  76                                 hwdev, sg[i].dma_address));
  77                 }
  78                 rc = nents;
  79         }
  80
  81         flush_write_buffers();
  82         return rc;
  83 }
  84 EXPORT_SYMBOL(dma_map_sg);
  85
  86 void
  87 dma_unmap_sg(struct device *hwdev, struct scatterlist *sg, int nents,
  88              enum dma_data_direction direction)
  89 {
  90         BUG_ON(direction == DMA_NONE);
  91         if (swiotlb)
  92                 swiotlb_unmap_sg(hwdev, sg, nents, direction);
  93 }
  94 EXPORT_SYMBOL(dma_unmap_sg);
  95
  96 /*
  97  * XXX This file is also used by xenLinux/ia64.
  98  * "defined(__i386__) || defined (__x86_64__)" means "!defined(__ia64__)".
  99  * This #if work around should be removed once this file is merbed back into
 100  * i386' pci-dma or is moved to drivers/xen/core.
 101  */
 102 #if defined(__i386__) || defined(__x86_64__)
 103 dma_addr_t
 104 dma_map_page(struct device *dev, struct page *page, unsigned long offset,
 105              size_t size, enum dma_data_direction direction)
 106 {
 107         dma_addr_t dma_addr;
 108
 109         BUG_ON(direction == DMA_NONE);
 110
 111         if (swiotlb) {
 112                 dma_addr = swiotlb_map_page(
 113                         dev, page, offset, size, direction);
 114         } else {
 115                 dma_addr = page_to_bus(page) + offset;
 116                 IOMMU_BUG_ON(address_needs_mapping(dev, dma_addr));
 117         }
 118
 119         return dma_addr;
 120 }
 121 EXPORT_SYMBOL(dma_map_page);
 122
 123 void
 124 dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
 125                enum dma_data_direction direction)
 126 {
 127         BUG_ON(direction == DMA_NONE);
 128         if (swiotlb)
 129                 swiotlb_unmap_page(dev, dma_address, size, direction);
 130 }
 131 EXPORT_SYMBOL(dma_unmap_page);
 132 #endif /* defined(__i386__) || defined(__x86_64__) */
 133
 134 int
 135 dma_mapping_error(dma_addr_t dma_addr)
 136 {
 137         if (swiotlb)
 138                 return swiotlb_dma_mapping_error(dma_addr);
 139         return 0;
 140 }
 141 EXPORT_SYMBOL(dma_mapping_error);
 142
 143 int
 144 dma_supported(struct device *dev, u64 mask)
 145 {
 146         if (swiotlb)
 147                 return swiotlb_dma_supported(dev, mask);
 148         /*
 149          * By default we'll BUG when an infeasible DMA is requested, and
 150          * request swiotlb=force (see IOMMU_BUG_ON).
 151          */
 152         return 1;
 153 }
 154 EXPORT_SYMBOL(dma_supported);
 155
 156 void *dma_alloc_coherent(struct device *dev, size_t size,
 157                            dma_addr_t *dma_handle, gfp_t gfp)
 158 {
 159         void *ret;
 160         struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
 161         unsigned int order = get_order(size);
 162         unsigned long vstart;
 163         /* ignore region specifiers */
 164         gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
 165
 166         if (mem) {
 167                 int page = bitmap_find_free_region(mem->bitmap, mem->size,
 168                                                      order);
 169                 if (page >= 0) {
 170                         *dma_handle = mem->device_base + (page << PAGE_SHIFT);
 171                         ret = mem->virt_base + (page << PAGE_SHIFT);
 172                         memset(ret, 0, size);
 173                         return ret;
 174                 }
 175                 if (mem->flags & DMA_MEMORY_EXCLUSIVE)
 176                         return NULL;
 177         }
 178
 179         if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
 180                 gfp |= GFP_DMA;
 181
 182         vstart = __get_free_pages(gfp, order);
 183         ret = (void *)vstart;
 184
 185         if (ret != NULL) {
 186                 /* NB. Hardcode 31 address bits for now: aacraid limitation. */
 187                 if (xen_create_contiguous_region(vstart, order, 31) != 0) {
 188                         free_pages(vstart, order);
 189                         return NULL;
 190                 }
 191                 memset(ret, 0, size);
 192                 *dma_handle = virt_to_bus(ret);
 193         }
 194         return ret;
 195 }
 196 EXPORT_SYMBOL(dma_alloc_coherent);
 197
 198 void dma_free_coherent(struct device *dev, size_t size,
 199                          void *vaddr, dma_addr_t dma_handle)
 200 {
 201         struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
 202         int order = get_order(size);
 203
 204         if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
 205                 int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
 206
 207                 bitmap_release_region(mem->bitmap, page, order);
 208         } else {
 209                 xen_destroy_contiguous_region((unsigned long)vaddr, order);
 210                 free_pages((unsigned long)vaddr, order);
 211         }
 212 }
 213 EXPORT_SYMBOL(dma_free_coherent);
 214
 215 #ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
 216 int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
 217                                 dma_addr_t device_addr, size_t size, int flags)
 218 {
 219         void __iomem *mem_base;
 220         int pages = size >> PAGE_SHIFT;
 221         int bitmap_size = (pages + 31)/32;
 222
 223         if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
 224                 goto out;
 225         if (!size)
 226                 goto out;
 227         if (dev->dma_mem)
 228                 goto out;
 229
 230         /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
 231
 232         mem_base = ioremap(bus_addr, size);
 233         if (!mem_base)
 234                 goto out;
 235
 236         dev->dma_mem = kmalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
 237         if (!dev->dma_mem)
 238                 goto out;
 239         memset(dev->dma_mem, 0, sizeof(struct dma_coherent_mem));
 240         dev->dma_mem->bitmap = kmalloc(bitmap_size, GFP_KERNEL);
 241         if (!dev->dma_mem->bitmap)
 242                 goto free1_out;
 243         memset(dev->dma_mem->bitmap, 0, bitmap_size);
 244
 245         dev->dma_mem->virt_base = mem_base;
 246         dev->dma_mem->device_base = device_addr;
 247         dev->dma_mem->size = pages;
 248         dev->dma_mem->flags = flags;
 249
 250         if (flags & DMA_MEMORY_MAP)
 251                 return DMA_MEMORY_MAP;
 252
 253         return DMA_MEMORY_IO;
 254
 255  free1_out:
 256         kfree(dev->dma_mem->bitmap);
 257  out:
 258         return 0;
 259 }
 260 EXPORT_SYMBOL(dma_declare_coherent_memory);
 261
 262 void dma_release_declared_memory(struct device *dev)
 263 {
 264         struct dma_coherent_mem *mem = dev->dma_mem;
 265
 266         if(!mem)
 267                 return;
 268         dev->dma_mem = NULL;
 269         iounmap(mem->virt_base);
 270         kfree(mem->bitmap);
 271         kfree(mem);
 272 }
 273 EXPORT_SYMBOL(dma_release_declared_memory);
 274
 275 void *dma_mark_declared_memory_occupied(struct device *dev,
 276                                         dma_addr_t device_addr, size_t size)
 277 {
 278         struct dma_coherent_mem *mem = dev->dma_mem;
 279         int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT;
 280         int pos, err;
 281
 282         if (!mem)
 283                 return ERR_PTR(-EINVAL);
 284
 285         pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
 286         err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
 287         if (err != 0)
 288                 return ERR_PTR(err);
 289         return mem->virt_base + (pos << PAGE_SHIFT);
 290 }
 291 EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
 292 #endif /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
 293
 294 dma_addr_t
 295 dma_map_single(struct device *dev, void *ptr, size_t size,
 296                enum dma_data_direction direction)
 297 {
 298         dma_addr_t dma;
 299
 300         if (direction == DMA_NONE)
 301                 BUG();
 302         WARN_ON(size == 0);
 303
 304         if (swiotlb) {
 305                 dma = swiotlb_map_single(dev, ptr, size, direction);
 306         } else {
 307                 dma = virt_to_bus(ptr);
 308                 IOMMU_BUG_ON(range_straddles_page_boundary(ptr, size));
 309                 IOMMU_BUG_ON(address_needs_mapping(dev, dma));
 310         }
 311
 312         flush_write_buffers();
 313         return dma;
 314 }
 315 EXPORT_SYMBOL(dma_map_single);
 316
 317 void
 318 dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
 319                  enum dma_data_direction direction)
 320 {
 321         if (direction == DMA_NONE)
 322                 BUG();
 323         if (swiotlb)
 324                 swiotlb_unmap_single(dev, dma_addr, size, direction);
 325 }
 326 EXPORT_SYMBOL(dma_unmap_single);
 327
 328 void
 329 dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size,
 330                         enum dma_data_direction direction)
 331 {
 332         if (swiotlb)
 333                 swiotlb_sync_single_for_cpu(dev, dma_handle, size, direction);
 334 }
 335 EXPORT_SYMBOL(dma_sync_single_for_cpu);
 336
 337 void
 338 dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size,
 339                            enum dma_data_direction direction)
 340 {
 341         if (swiotlb)
 342                 swiotlb_sync_single_for_device(dev, dma_handle, size, direction);
 343 }
 344 EXPORT_SYMBOL(dma_sync_single_for_device);