arm: introduce is_device_dma_coherent

Introduce a boolean flag and an accessor function to check whether a
device is dma_coherent. Set the flag from set_arch_dma_coherent_ops.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King <linux@arm.linux.org.uk>

diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
index dc662fc..4111592 100644 (file)
--- a/arch/arm/include/asm/device.h
+++ b/arch/arm/include/asm/device.h
@@ -17,6 +17,7 @@ struct dev_archdata {
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
        struct dma_iommu_mapping        *mapping;
 #endif
+       bool dma_coherent;
 };
 
 struct omap_device;

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 85738b2..e6e3446 100644 (file)
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -123,11 +123,18 @@ static inline unsigned long dma_max_pfn(struct device *dev)
 
 static inline int set_arch_dma_coherent_ops(struct device *dev)
 {
+       dev->archdata.dma_coherent = true;
        set_dma_ops(dev, &arm_coherent_dma_ops);
        return 0;
 }
 #define set_arch_dma_coherent_ops(dev) set_arch_dma_coherent_ops(dev)
 
+/* do not use this function in a driver */
+static inline bool is_device_dma_coherent(struct device *dev)
+{
+       return dev->archdata.dma_coherent;
+}
+
 static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
 {
        unsigned int offset = paddr & ~PAGE_MASK;