]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - kernel/dma-coherent.c
dma_alloc_coherent: clean it up
[linux-2.6-omap-h63xx.git] / kernel / dma-coherent.c
index 4bdcea822b45f200a2b60190c2be11709a90ba49..8056d081609caacd13b26e3dceedd6b07cd5550e 100644 (file)
@@ -109,34 +109,38 @@ EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
 int dma_alloc_from_coherent(struct device *dev, ssize_t size,
                                       dma_addr_t *dma_handle, void **ret)
 {
-       struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+       struct dma_coherent_mem *mem;
        int order = get_order(size);
+       int pageno;
 
-       if (mem) {
-               int page = bitmap_find_free_region(mem->bitmap, mem->size,
-                                                    order);
-               if (page >= 0) {
-                       /*
-                        * Memory was found in the per-device arena.
-                        */
-                       *dma_handle = mem->device_base + (page << PAGE_SHIFT);
-                       *ret = mem->virt_base + (page << PAGE_SHIFT);
-                       memset(*ret, 0, size);
-               } else if (mem->flags & DMA_MEMORY_EXCLUSIVE) {
-                       /*
-                        * The per-device arena is exhausted and we are not
-                        * permitted to fall back to generic memory.
-                        */
-                       *ret = NULL;
-               } else {
-                       /*
-                        * The per-device arena is exhausted and we are
-                        * permitted to fall back to generic memory.
-                        */
-                        return 0;
-               }
+       if (!dev)
+               return 0;
+       mem = dev->dma_mem;
+       if (!mem)
+               return 0;
+
+       pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
+       if (pageno >= 0) {
+               /*
+                * Memory was found in the per-device arena.
+                */
+               *dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
+               *ret = mem->virt_base + (pageno << PAGE_SHIFT);
+               memset(*ret, 0, size);
+       } else if (mem->flags & DMA_MEMORY_EXCLUSIVE) {
+               /*
+                * The per-device arena is exhausted and we are not
+                * permitted to fall back to generic memory.
+                */
+               *ret = NULL;
+       } else {
+               /*
+                * The per-device arena is exhausted and we are
+                * permitted to fall back to generic memory.
+                */
+                return 0;
        }
-       return (mem != NULL);
+       return 1;
 }
 EXPORT_SYMBOL(dma_alloc_from_coherent);