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 paramater is ignored and the normal ops are used instead. Signed-off-by: Will Deacon <[email protected]> --- arch/arm/include/asm/dma-mapping.h | 9 ++--- arch/arm/mm/dma-mapping.c | 68 +++++++++++++++++++++++++++++++++----- 2 files changed, 62 insertions(+), 15 deletions(-) diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index a8bb0c494bb3..e1cd4445c100 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -121,14 +121,9 @@ 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_dma_mapping *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_dma_mapping *iommu, bool coherent); 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 7a996aaa061e..bcd5f836f27e 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2041,10 +2041,9 @@ EXPORT_SYMBOL_GPL(arm_iommu_release_mapping); * @mapping: io address space mapping structure (returned from * 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. + * Attaches specified io address space mapping to the provided device. + * 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) @@ -2057,7 +2056,6 @@ 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; @@ -2069,7 +2067,6 @@ 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) { @@ -2084,10 +2081,65 @@ 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 bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size) +{ + struct dma_iommu_mapping *mapping; + + 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 attach device %s to IOMMU mapping\n", + dev_name(dev)); + arm_iommu_release_mapping(mapping); + return false; + } + + return true; +} + +static struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent) +{ + return coherent ? &iommu_coherent_ops : &iommu_ops; +} + +#else + +static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size) +{ + return false; +} + +#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_dma_mapping *iommu, bool coherent) +{ + struct dma_map_ops *dma_ops; + + if (iommu && arm_setup_iommu_dma_ops(dev, dma_base, size)) { + dev->dma_pfn_offset = 0; + dma_ops = arm_get_iommu_dma_map_ops(coherent); + } else { + dma_ops = arm_get_dma_map_ops(coherent); + } + + set_dma_ops(dev, dma_ops); +} +EXPORT_SYMBOL_GPL(arch_setup_dma_ops); -- 2.1.0 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
