This patch adds 2 helpers: arm_iommu_create_default_mapping and arm_iommu_release_default_mapping for managing default iommu-based dma-mapping address space, created for exlusive use only by the given device. Those helpers are convenient for setting up iommu-based dma-mapping for most typical devices in the system.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- arch/arm/include/asm/dma-iommu.h | 5 +++++ arch/arm/mm/dma-mapping.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+)
diff --git a/arch/arm/include/asm/dma-iommu.h b/arch/arm/include/asm/dma-iommu.h index 8e3fcb9..ae3dac0 100644 --- a/arch/arm/include/asm/dma-iommu.h +++ b/arch/arm/include/asm/dma-iommu.h @@ -33,5 +33,10 @@ int arm_iommu_attach_device(struct device *dev, struct dma_iommu_mapping *mapping); void arm_iommu_detach_device(struct device *dev);
+int arm_iommu_create_default_mapping(struct device *dev, dma_addr_t base, + size_t size); + +void arm_iommu_release_default_mapping(struct device *dev); + #endif /* __KERNEL__ */ #endif diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 8161102..233a8cf 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2106,4 +2106,35 @@ void arm_iommu_detach_device(struct device *dev) } EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
+int arm_iommu_create_default_mapping(struct device *dev, dma_addr_t base, + size_t size) +{ + struct dma_iommu_mapping *mapping; + int ret; + + mapping = arm_iommu_create_mapping(dev->bus, base, size); + if (IS_ERR(mapping)) + return PTR_ERR(mapping); + + ret = arm_iommu_attach_device(dev, mapping); + if (ret) { + arm_iommu_release_mapping(mapping); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(arm_iommu_create_default_mapping); + +void arm_iommu_release_default_mapping(struct device *dev) +{ + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev); + if (!mapping) + return; + + arm_iommu_detach_device(dev); + arm_iommu_release_mapping(mapping); +} +EXPORT_SYMBOL_GPL(arm_iommu_release_default_mapping); + #endif