[ARM] Move dma_alloc_coherent() to consistent.c

arch/arm/mm/consistent.c

@@ -10,7 +10,7 @@
  *  DMA uncached mapping support.
  */
 #include <linux/config.h>
-#include <linux/types.h>
+#include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/string.h>
@@ -145,6 +145,7 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *handle,
 	struct vm_region *c;
 	unsigned long order, flags;
 	void *ret = NULL;
+	int res;
 
 	if (!consistent_pte) {
 		printk(KERN_ERR "consistent_alloc: not initialised\n");
@@ -177,14 +178,19 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *handle,
 	if (!c)
 		goto no_remap;
 
-	spin_lock_irqsave(&consistent_lock, flags);
-	vm_region_dump(&consistent_head, "before alloc");
-
 	/*
 	 * Attempt to allocate a virtual address in the
 	 * consistent mapping region.
 	 */
-	if (!vm_region_alloc(&consistent_head, c, size)) {
+	spin_lock_irqsave(&consistent_lock, flags);
+	vm_region_dump(&consistent_head, "before alloc");
+
+	res = vm_region_alloc(&consistent_head, c, size);
+
+	vm_region_dump(&consistent_head, "after alloc");
+	spin_unlock_irqrestore(&consistent_lock, flags);
+
+	if (!res) {
 		pte_t *pte = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
 		struct page *end = page + (1 << order);
 		pgprot_t prot = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
@@ -218,9 +224,6 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *handle,
 		ret = (void *)c->vm_start;
 	}
 
-	vm_region_dump(&consistent_head, "after alloc");
-	spin_unlock_irqrestore(&consistent_lock, flags);
-
  no_remap:
 	if (ret == NULL) {
 		kfree(c);
@@ -230,6 +233,22 @@ void *consistent_alloc(int gfp, size_t size, dma_addr_t *handle,
 	return ret;
 }
 
+/*
+ * Since we have the DMA mask available to us here, we could try to do
+ * a normal allocation, and only fall back to a "DMA" allocation if the
+ * resulting bus address does not satisfy the dma_mask requirements.
+ */
+void *
+dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, int gfp)
+{
+	if (dev == NULL || *dev->dma_mask != 0xffffffff)
+		gfp |= GFP_DMA;
+
+	return consistent_alloc(gfp, size, handle, 0);
+}
+
+EXPORT_SYMBOL(dma_alloc_coherent);
+
 /*
  * free a page as defined by the above mapping.
  */

include/asm-arm/dma-mapping.h

@@ -42,12 +42,12 @@ extern struct bus_type sa1111_bus_type;
 /*
  * Return whether the given device DMA address mask can be supported
  * properly.  For example, if your device can only drive the low 24-bits
- * during PCI bus mastering, then you would pass 0x00ffffff as the mask
+ * during bus mastering, then you would pass 0x00ffffff as the mask
  * to this function.
  */
 static inline int dma_supported(struct device *dev, u64 mask)
 {
-	return 1;
+	return dev->dma_mask && *dev->dma_mask != 0;
 }
 
 static inline int dma_set_mask(struct device *dev, u64 dma_mask)
@@ -81,14 +81,8 @@ static inline int dma_is_consistent(dma_addr_t handle)
  * return the CPU-viewed address, and sets @handle to be the
  * device-viewed address.
  */
-static inline void *
-dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, int gfp)
-{
-	if (dev == NULL || dmadev_is_sa1111(dev) || *dev->dma_mask != 0xffffffff)
-		gfp |= GFP_DMA;
-
-	return consistent_alloc(gfp, size, handle, 0);
-}
+extern void *
+dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, int gfp);
 
 /**
  * dma_free_coherent - free memory allocated by dma_alloc_coherent