Pileus Git - ~andy/linux/blob - arch/m68k/kernel/dma.c

   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);