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>

2 files changed, 9 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c7ad324ddf2c..ea8b9be02b60 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -16,6 +16,7 @@ config ARM
         select HAVE_KRETPROBES if (HAVE_KPROBES)
         select HAVE_FTRACE if (!XIP_KERNEL)
         select HAVE_DYNAMIC_FTRACE if (HAVE_FTRACE)
+        select HAVE_GENERIC_DMA_COHERENT
         help
           The ARM series is a line of low-power-consumption RISC chip designs
           licensed by ARM Ltd and targeted at embedded applications and
diff --git a/arch/arm/mm/consistent.c b/arch/arm/mm/consistent.c
index 333a82a3717e..db7b3e38ef1d 100644
--- a/arch/arm/mm/consistent.c
+++ b/arch/arm/mm/consistent.c
@@ -274,6 +274,11 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
 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 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
 
         WARN_ON(irqs_disabled());
 
+        if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
+                return;
+
         if (arch_is_coherent()) {
                 kfree(cpu_addr);
                 return;