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 7 #undef DEBUG 8 9 #include <linux/dma-mapping.h> 10 #include <linux/device.h> 11 #include <linux/kernel.h> 12 #include <linux/scatterlist.h> 13 #include <linux/vmalloc.h> 14 15 #include <asm/pgalloc.h> 16 17 void *dma_alloc_coherent(struct device *dev, size_t size, 18 dma_addr_t *handle, gfp_t flag) 19 { 20 struct page *page, **map; 21 pgprot_t pgprot; 22 void *addr; 23 int i, order; 24 25 pr_debug("dma_alloc_coherent: %d,%x\n", size, flag); 26 27 size = PAGE_ALIGN(size); 28 order = get_order(size); 29 30 page = alloc_pages(flag, order); 31 if (!page) 32 return NULL; 33 34 *handle = page_to_phys(page); 35 map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA); 36 if (!map) { 37 __free_pages(page, order); 38 return NULL; 39 } 40 split_page(page, order); 41 42 order = 1 << order; 43 size >>= PAGE_SHIFT; 44 map[0] = page; 45 for (i = 1; i < size; i++) 46 map[i] = page + i; 47 for (; i < order; i++) 48 __free_page(page + i); 49 pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY); 50 if (CPU_IS_040_OR_060) 51 pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S; 52 else 53 pgprot_val(pgprot) |= _PAGE_NOCACHE030; 54 addr = vmap(map, size, VM_MAP, pgprot); 55 kfree(map); 56 57 return addr; 58 } 59 EXPORT_SYMBOL(dma_alloc_coherent); 60 61 void dma_free_coherent(struct device *dev, size_t size, 62 void *addr, dma_addr_t handle) 63 { 64 pr_debug("dma_free_coherent: %p, %x\n", addr, handle); 65 vfree(addr); 66 } 67 EXPORT_SYMBOL(dma_free_coherent); 68 69 void dma_sync_single_for_device(struct device *dev, dma_addr_t handle, 70 size_t size, enum dma_data_direction dir) 71 { 72 switch (dir) { 73 case DMA_TO_DEVICE: 74 cache_push(handle, size); 75 break; 76 case DMA_FROM_DEVICE: 77 cache_clear(handle, size); 78 break; 79 default: 80 if (printk_ratelimit()) 81 printk("dma_sync_single_for_device: unsupported dir %u\n", dir); 82 break; 83 } 84 } 85 EXPORT_SYMBOL(dma_sync_single_for_device); 86 87 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, 88 enum dma_data_direction dir) 89 { 90 int i; 91 92 for (i = 0; i < nents; sg++, i++) 93 dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir); 94 } 95 EXPORT_SYMBOL(dma_sync_sg_for_device); 96 97 dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size, 98 enum dma_data_direction dir) 99 { 100 dma_addr_t handle = virt_to_bus(addr); 101 102 dma_sync_single_for_device(dev, handle, size, dir); 103 return handle; 104 } 105 EXPORT_SYMBOL(dma_map_single); 106 107 dma_addr_t dma_map_page(struct device *dev, struct page *page, 108 unsigned long offset, size_t size, 109 enum dma_data_direction dir) 110 { 111 dma_addr_t handle = page_to_phys(page) + offset; 112 113 dma_sync_single_for_device(dev, handle, size, dir); 114 return handle; 115 } 116 EXPORT_SYMBOL(dma_map_page); 117 118 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, 119 enum dma_data_direction dir) 120 { 121 int i; 122 123 for (i = 0; i < nents; sg++, i++) { 124 sg->dma_address = sg_phys(sg); 125 dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir); 126 } 127 return nents; 128 } 129 EXPORT_SYMBOL(dma_map_sg); 130