dma-mapping.c 1.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
  3. #include <linux/cache.h>
  4. #include <linux/dma-map-ops.h>
  5. #include <linux/genalloc.h>
  6. #include <linux/highmem.h>
  7. #include <linux/io.h>
  8. #include <linux/mm.h>
  9. #include <linux/scatterlist.h>
  10. #include <linux/types.h>
  11. #include <asm/cache.h>
  12. static inline void cache_op(phys_addr_t paddr, size_t size,
  13. void (*fn)(unsigned long start, unsigned long end))
  14. {
  15. struct page *page = phys_to_page(paddr);
  16. void *start = __va(page_to_phys(page));
  17. unsigned long offset = offset_in_page(paddr);
  18. size_t left = size;
  19. do {
  20. size_t len = left;
  21. if (offset + len > PAGE_SIZE)
  22. len = PAGE_SIZE - offset;
  23. if (PageHighMem(page)) {
  24. start = kmap_atomic(page);
  25. fn((unsigned long)start + offset,
  26. (unsigned long)start + offset + len);
  27. kunmap_atomic(start);
  28. } else {
  29. fn((unsigned long)start + offset,
  30. (unsigned long)start + offset + len);
  31. }
  32. offset = 0;
  33. page++;
  34. start += PAGE_SIZE;
  35. left -= len;
  36. } while (left);
  37. }
  38. static void dma_wbinv_set_zero_range(unsigned long start, unsigned long end)
  39. {
  40. memset((void *)start, 0, end - start);
  41. dma_wbinv_range(start, end);
  42. }
  43. void arch_dma_prep_coherent(struct page *page, size_t size)
  44. {
  45. cache_op(page_to_phys(page), size, dma_wbinv_set_zero_range);
  46. }
  47. void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
  48. enum dma_data_direction dir)
  49. {
  50. switch (dir) {
  51. case DMA_TO_DEVICE:
  52. cache_op(paddr, size, dma_wb_range);
  53. break;
  54. case DMA_FROM_DEVICE:
  55. case DMA_BIDIRECTIONAL:
  56. cache_op(paddr, size, dma_wbinv_range);
  57. break;
  58. default:
  59. BUG();
  60. }
  61. }
  62. void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
  63. enum dma_data_direction dir)
  64. {
  65. switch (dir) {
  66. case DMA_TO_DEVICE:
  67. return;
  68. case DMA_FROM_DEVICE:
  69. case DMA_BIDIRECTIONAL:
  70. cache_op(paddr, size, dma_inv_range);
  71. break;
  72. default:
  73. BUG();
  74. }
  75. }