arch/m68knommu/kernel/dma.c

   1 /*
   2  * Dynamic DMA mapping support.
   3  *
   4  * We never have any address translations to worry about, so this
   5  * is just alloc/free.
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/mm.h>
  10 #include <linux/device.h>
  11 #include <linux/dma-mapping.h>
  12 #include <asm/cacheflush.h>
  13
  14 void *dma_alloc_coherent(struct device *dev, size_t size,
  15                            dma_addr_t *dma_handle, gfp_t gfp)
  16 {
  17         void *ret;
  18         /* ignore region specifiers */
  19         gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
  20
  21         if (dev == NULL || (*dev->dma_mask < 0xffffffff))
  22                 gfp |= GFP_DMA;
  23         ret = (void *)__get_free_pages(gfp, get_order(size));
  24
  25         if (ret != NULL) {
  26                 memset(ret, 0, size);
  27                 *dma_handle = virt_to_phys(ret);
  28         }
  29         return ret;
  30 }
  31
  32 void dma_free_coherent(struct device *dev, size_t size,
  33                          void *vaddr, dma_addr_t dma_handle)
  34 {
  35         free_pages((unsigned long)vaddr, get_order(size));
  36 }
  37
  38 void dma_sync_single_for_device(struct device *dev, dma_addr_t handle,
  39                                 size_t size, enum dma_data_direction dir)
  40 {
  41         switch (dir) {
  42         case DMA_TO_DEVICE:
  43                 flush_dcache_range(handle, size);
  44                 break;
  45         case DMA_FROM_DEVICE:
  46                 /* Should be clear already */
  47                 break;
  48         default:
  49                 if (printk_ratelimit())
  50                         printk("dma_sync_single_for_device: unsupported dir %u\n", dir);
  51                 break;
  52         }
  53 }
  54
  55 EXPORT_SYMBOL(dma_sync_single_for_device);
  56 dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size,
  57                           enum dma_data_direction dir)
  58 {
  59         dma_addr_t handle = virt_to_phys(addr);
  60         flush_dcache_range(handle, size);
  61         return handle;
  62 }
  63 EXPORT_SYMBOL(dma_map_single);
  64
  65 dma_addr_t dma_map_page(struct device *dev, struct page *page,
  66                         unsigned long offset, size_t size,
  67                         enum dma_data_direction dir)
  68 {
  69         dma_addr_t handle = page_to_phys(page) + offset;
  70         dma_sync_single_for_device(dev, handle, size, dir);
  71         return handle;
  72 }
  73 EXPORT_SYMBOL(dma_map_page);