From 4bb25789ed28228a52c030bf28edb2fcdb214be8 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 27 Aug 2014 17:52:44 +0100 Subject: [PATCH] arm: dma-mapping: plumb our iommu mapping ops into arch_setup_dma_ops This patch plumbs the existing ARM IOMMU DMA infrastructure (which isn't actually called outside of a few drivers) into arch_setup_dma_ops, so that we can use IOMMUs for DMA transfers in a more generic fashion. Since this significantly complicates the arch_setup_dma_ops function, it is moved out of line into dma-mapping.c. If CONFIG_ARM_DMA_USE_IOMMU is not set, the iommu parameter is ignored and the normal ops are used instead. Acked-by: Russell King Acked-by: Arnd Bergmann Acked-by: Marek Szyprowski Signed-off-by: Will Deacon --- arch/arm/include/asm/dma-mapping.h | 12 ++--- arch/arm/mm/dma-mapping.c | 83 +++++++++++++++++++++++++++--- 2 files changed, 81 insertions(+), 14 deletions(-) diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index f3c0d953f6a2..9410b7e548fc 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -121,14 +121,12 @@ static inline unsigned long dma_max_pfn(struct device *dev) } #define dma_max_pfn(dev) dma_max_pfn(dev) -static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, - u64 size, struct iommu_ops *iommu, - bool coherent) -{ - if (coherent) - set_dma_ops(dev, &arm_coherent_dma_ops); -} #define arch_setup_dma_ops arch_setup_dma_ops +extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu, bool coherent); + +#define arch_teardown_dma_ops arch_teardown_dma_ops +extern void arch_teardown_dma_ops(struct device *dev); static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) { diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index e8907117861e..09645f00bd17 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1947,9 +1947,8 @@ EXPORT_SYMBOL_GPL(arm_iommu_release_mapping); * arm_iommu_create_mapping) * * Attaches specified io address space mapping to the provided device, - * this replaces the dma operations (dma_map_ops pointer) with the - * IOMMU aware version. More than one client might be attached to - * the same io address space mapping. + * More than one client might be attached to the same io address space + * mapping. */ int arm_iommu_attach_device(struct device *dev, struct dma_iommu_mapping *mapping) @@ -1962,7 +1961,6 @@ int arm_iommu_attach_device(struct device *dev, kref_get(&mapping->kref); dev->archdata.mapping = mapping; - set_dma_ops(dev, &iommu_ops); pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev)); return 0; @@ -1974,7 +1972,6 @@ EXPORT_SYMBOL_GPL(arm_iommu_attach_device); * @dev: valid struct device pointer * * Detaches the provided device from a previously attached map. - * This voids the dma operations (dma_map_ops pointer) */ void arm_iommu_detach_device(struct device *dev) { @@ -1989,10 +1986,82 @@ void arm_iommu_detach_device(struct device *dev) iommu_detach_device(mapping->domain, dev); kref_put(&mapping->kref, release_iommu_mapping); dev->archdata.mapping = NULL; - set_dma_ops(dev, NULL); pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev)); } EXPORT_SYMBOL_GPL(arm_iommu_detach_device); -#endif +static struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent) +{ + return coherent ? &iommu_coherent_ops : &iommu_ops; +} + +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu) +{ + struct dma_iommu_mapping *mapping; + + if (!iommu) + return false; + + mapping = arm_iommu_create_mapping(dev->bus, dma_base, size); + if (IS_ERR(mapping)) { + pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n", + size, dev_name(dev)); + return false; + } + + if (arm_iommu_attach_device(dev, mapping)) { + pr_warn("Failed to attached device %s to IOMMU_mapping\n", + dev_name(dev)); + arm_iommu_release_mapping(mapping); + return false; + } + + return true; +} + +static void arm_teardown_iommu_dma_ops(struct device *dev) +{ + struct dma_iommu_mapping *mapping = dev->archdata.mapping; + + arm_iommu_detach_device(dev); + arm_iommu_release_mapping(mapping); +} + +#else + +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu) +{ + return false; +} + +static void arm_teardown_iommu_dma_ops(struct device *dev) { } + +#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops + +#endif /* CONFIG_ARM_DMA_USE_IOMMU */ + +static struct dma_map_ops *arm_get_dma_map_ops(bool coherent) +{ + return coherent ? &arm_coherent_dma_ops : &arm_dma_ops; +} + +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu, bool coherent) +{ + struct dma_map_ops *dma_ops; + + if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) + dma_ops = arm_get_iommu_dma_map_ops(coherent); + else + dma_ops = arm_get_dma_map_ops(coherent); + + set_dma_ops(dev, dma_ops); +} + +void arch_teardown_dma_ops(struct device *dev) +{ + arm_teardown_iommu_dma_ops(dev); +} -- 2.20.1