Update the generic DMA API to take GFP_ flags on allocation

dma_alloc_[non]coherent now takes the GFP_ flags as the last argument.
The flags passed in may not interfere with the memory zone.

Documentation/DMA-API.txt

@@ -22,7 +22,7 @@ To get the dma_ API, you must #include <linux/dma-mapping.h>
 
 void *
 dma_alloc_coherent(struct device *dev, size_t size,
-			     dma_addr_t *dma_handle)
+			     dma_addr_t *dma_handle, int flag)
 void *
 pci_alloc_consistent(struct pci_dev *dev, size_t size,
 			     dma_addr_t *dma_handle)
@@ -43,6 +43,12 @@ Note: consistent memory can be expensive on some platforms, and the
 minimum allocation length may be as big as a page, so you should
 consolidate your requests for consistent memory as much as possible.
 
+The flag parameter (dma_alloc_coherent only) allows the caller to
+specify the GFP_ flags (see kmalloc) for the allocation (the
+implementation may chose to ignore flags that affect the location of
+the returned memory, like GFP_DMA).  For pci_alloc_consistent, you
+must assume GFP_ATOMIC behaviour.
+
 void
 dma_free_coherent(struct device *dev, size_t size, void *cpu_addr
 			   dma_addr_t dma_handle)
@@ -261,7 +267,7 @@ API at all.
 
 void *
 dma_alloc_noncoherent(struct device *dev, size_t size,
-			       dma_addr_t *dma_handle)
+			       dma_addr_t *dma_handle, int flag)
 
 Identical to dma_alloc_coherent() except that the platform will
 choose to return either consistent or non-consistent memory as it sees

include/asm-generic/dma-mapping.h

@@ -30,9 +30,10 @@ dma_set_mask(struct device *dev, u64 dma_mask)
 }
 
 static inline void *
-dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle)
+dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		   int flag)
 {
-	BUG_ON(dev->bus != &pci_bus_type);
+	BUG_ON(dev->bus != &pci_bus_type || (flag & GFP_ATOMIC) != GFP_ATOMIC);
 
 	return pci_alloc_consistent(to_pci_dev(dev), size, dma_handle);
 }
@@ -121,7 +122,7 @@ dma_sync_sg(struct device *dev, struct scatterlist *sg, int nelems,
 
 /* Now for the API extensions over the pci_ one */
 
-#define dma_alloc_noncoherent(d, s, h) dma_alloc_coherent(d, s, h)
+#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
 #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
 #define dma_is_consistent(d)	(1)
 

include/asm-generic/pci-dma-compat.h

@@ -19,7 +19,7 @@ static inline void *
 pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
 		     dma_addr_t *dma_handle)
 {
-	return dma_alloc_coherent(hwdev == NULL ? NULL : &hwdev->dev, size, dma_handle);
+	return dma_alloc_coherent(hwdev == NULL ? NULL : &hwdev->dev, size, dma_handle, GFP_ATOMIC);
 }
 
 static inline void