ARM: support generic per-device coherent dma mem

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/arm/mm/consistent.c b/arch/arm/mm/consistent.c
index 333a82a..db7b3e3 100644
--- a/arch/arm/mm/consistent.c
+++ b/arch/arm/mm/consistent.c
@@ -274,6 +274,11 @@
 void *
 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
 {
+	void *memory;
+
+	if (dma_alloc_from_coherent(dev, size, handle, &memory))
+		return memory;
+
 	if (arch_is_coherent()) {
 		void *virt;
 
@@ -362,6 +367,9 @@
 
 	WARN_ON(irqs_disabled());
 
+	if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
+		return;
+
 	if (arch_is_coherent()) {
 		kfree(cpu_addr);
 		return;