dma_mm.c 3.1 KB

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  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. #undef DEBUG
  7. #include <linux/dma-mapping.h>
  8. #include <linux/device.h>
  9. #include <linux/kernel.h>
  10. #include <linux/scatterlist.h>
  11. #include <linux/slab.h>
  12. #include <linux/vmalloc.h>
  13. #include <linux/export.h>
  14. #include <asm/pgalloc.h>
  15. void *dma_alloc_coherent(struct device *dev, size_t size,
  16. dma_addr_t *handle, gfp_t flag)
  17. {
  18. struct page *page, **map;
  19. pgprot_t pgprot;
  20. void *addr;
  21. int i, order;
  22. pr_debug("dma_alloc_coherent: %d,%x\n", size, flag);
  23. size = PAGE_ALIGN(size);
  24. order = get_order(size);
  25. page = alloc_pages(flag, order);
  26. if (!page)
  27. return NULL;
  28. *handle = page_to_phys(page);
  29. map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA);
  30. if (!map) {
  31. __free_pages(page, order);
  32. return NULL;
  33. }
  34. split_page(page, order);
  35. order = 1 << order;
  36. size >>= PAGE_SHIFT;
  37. map[0] = page;
  38. for (i = 1; i < size; i++)
  39. map[i] = page + i;
  40. for (; i < order; i++)
  41. __free_page(page + i);
  42. pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
  43. if (CPU_IS_040_OR_060)
  44. pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S;
  45. else
  46. pgprot_val(pgprot) |= _PAGE_NOCACHE030;
  47. addr = vmap(map, size, VM_MAP, pgprot);
  48. kfree(map);
  49. return addr;
  50. }
  51. EXPORT_SYMBOL(dma_alloc_coherent);
  52. void dma_free_coherent(struct device *dev, size_t size,
  53. void *addr, dma_addr_t handle)
  54. {
  55. pr_debug("dma_free_coherent: %p, %x\n", addr, handle);
  56. vfree(addr);
  57. }
  58. EXPORT_SYMBOL(dma_free_coherent);
  59. void dma_sync_single_for_device(struct device *dev, dma_addr_t handle,
  60. size_t size, enum dma_data_direction dir)
  61. {
  62. switch (dir) {
  63. case DMA_TO_DEVICE:
  64. cache_push(handle, size);
  65. break;
  66. case DMA_FROM_DEVICE:
  67. cache_clear(handle, size);
  68. break;
  69. default:
  70. if (printk_ratelimit())
  71. printk("dma_sync_single_for_device: unsupported dir %u\n", dir);
  72. break;
  73. }
  74. }
  75. EXPORT_SYMBOL(dma_sync_single_for_device);
  76. void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
  77. enum dma_data_direction dir)
  78. {
  79. int i;
  80. for (i = 0; i < nents; sg++, i++)
  81. dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
  82. }
  83. EXPORT_SYMBOL(dma_sync_sg_for_device);
  84. dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size,
  85. enum dma_data_direction dir)
  86. {
  87. dma_addr_t handle = virt_to_bus(addr);
  88. dma_sync_single_for_device(dev, handle, size, dir);
  89. return handle;
  90. }
  91. EXPORT_SYMBOL(dma_map_single);
  92. dma_addr_t dma_map_page(struct device *dev, struct page *page,
  93. unsigned long offset, size_t size,
  94. enum dma_data_direction dir)
  95. {
  96. dma_addr_t handle = page_to_phys(page) + offset;
  97. dma_sync_single_for_device(dev, handle, size, dir);
  98. return handle;
  99. }
  100. EXPORT_SYMBOL(dma_map_page);
  101. int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  102. enum dma_data_direction dir)
  103. {
  104. int i;
  105. for (i = 0; i < nents; sg++, i++) {
  106. sg->dma_address = sg_phys(sg);
  107. dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
  108. }
  109. return nents;
  110. }
  111. EXPORT_SYMBOL(dma_map_sg);