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/slab.h> 14 #include <linux/vmalloc.h> 15 #include <linux/export.h> 16 17 #include <asm/pgalloc.h> 18 19 #ifdef CONFIG_MMU 20 21 void *dma_alloc_coherent(struct device *dev, size_t size, 22 dma_addr_t *handle, gfp_t flag) 23 { 24 struct page *page, **map; 25 pgprot_t pgprot; 26 void *addr; 27 int i, order; 28 29 pr_debug("dma_alloc_coherent: %d,%x\n", size, flag); 30 31 size = PAGE_ALIGN(size); 32 order = get_order(size); 33 34 page = alloc_pages(flag, order); 35 if (!page) 36 return NULL; 37 38 *handle = page_to_phys(page); 39 map = kmalloc(sizeof(struct page *) << order, flag & ~__GFP_DMA); 40 if (!map) { 41 __free_pages(page, order); 42 return NULL; 43 } 44 split_page(page, order); 45 46 order = 1 << order; 47 size >>= PAGE_SHIFT; 48 map[0] = page; 49 for (i = 1; i < size; i++) 50 map[i] = page + i; 51 for (; i < order; i++) 52 __free_page(page + i); 53 pgprot = __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY); 54 if (CPU_IS_040_OR_060) 55 pgprot_val(pgprot) |= _PAGE_GLOBAL040 | _PAGE_NOCACHE_S; 56 else 57 pgprot_val(pgprot) |= _PAGE_NOCACHE030; 58 addr = vmap(map, size, VM_MAP, pgprot); 59 kfree(map); 60 61 return addr; 62 } 63 64 void dma_free_coherent(struct device *dev, size_t size, 65 void *addr, dma_addr_t handle) 66 { 67 pr_debug("dma_free_coherent: %p, %x\n", addr, handle); 68 vfree(addr); 69 } 70 71 #else 72 73 #include <asm/cacheflush.h> 74 75 void *dma_alloc_coherent(struct device *dev, size_t size, 76 dma_addr_t *dma_handle, gfp_t gfp) 77 { 78 void *ret; 79 /* ignore region specifiers */ 80 gfp &= ~(__GFP_DMA | __GFP_HIGHMEM); 81 82 if (dev == NULL || (*dev->dma_mask < 0xffffffff)) 83 gfp |= GFP_DMA; 84 ret = (void *)__get_free_pages(gfp, get_order(size)); 85 86 if (ret != NULL) { 87 memset(ret, 0, size); 88 *dma_handle = virt_to_phys(ret); 89 } 90 return ret; 91 } 92 93 void dma_free_coherent(struct device *dev, size_t size, 94 void *vaddr, dma_addr_t dma_handle) 95 { 96 free_pages((unsigned long)vaddr, get_order(size)); 97 } 98 99 #endif /* CONFIG_MMU */ 100 101 EXPORT_SYMBOL(dma_alloc_coherent); 102 EXPORT_SYMBOL(dma_free_coherent); 103 104 void dma_sync_single_for_device(struct device *dev, dma_addr_t handle, 105 size_t size, enum dma_data_direction dir) 106 { 107 switch (dir) { 108 case DMA_TO_DEVICE: 109 cache_push(handle, size); 110 break; 111 case DMA_FROM_DEVICE: 112 cache_clear(handle, size); 113 break; 114 default: 115 if (printk_ratelimit()) 116 printk("dma_sync_single_for_device: unsupported dir %u\n", dir); 117 break; 118 } 119 } 120 EXPORT_SYMBOL(dma_sync_single_for_device); 121 122 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, 123 enum dma_data_direction dir) 124 { 125 int i; 126 127 for (i = 0; i < nents; sg++, i++) 128 dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir); 129 } 130 EXPORT_SYMBOL(dma_sync_sg_for_device); 131 132 dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size, 133 enum dma_data_direction dir) 134 { 135 dma_addr_t handle = virt_to_bus(addr); 136 137 dma_sync_single_for_device(dev, handle, size, dir); 138 return handle; 139 } 140 EXPORT_SYMBOL(dma_map_single); 141 142 dma_addr_t dma_map_page(struct device *dev, struct page *page, 143 unsigned long offset, size_t size, 144 enum dma_data_direction dir) 145 { 146 dma_addr_t handle = page_to_phys(page) + offset; 147 148 dma_sync_single_for_device(dev, handle, size, dir); 149 return handle; 150 } 151 EXPORT_SYMBOL(dma_map_page); 152 153 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, 154 enum dma_data_direction dir) 155 { 156 int i; 157 158 for (i = 0; i < nents; sg++, i++) { 159 sg->dma_address = sg_phys(sg); 160 dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir); 161 } 162 return nents; 163 } 164 EXPORT_SYMBOL(dma_map_sg); 165