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/vmalloc.h>
  13
  14 #include <asm/pgalloc.h>
  15 #include <asm/scatterlist.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 inline void dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
  70                                        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 = page_to_phys(sg->page) + sg->offset;
 125                 dma_sync_single_for_device(dev, sg->dma_address, sg->length, dir);
 126         }
 127         return nents;
 128 }
 129 EXPORT_SYMBOL(dma_map_sg);