From 44bb7e243bd4b4e5c79de2452cd9762582f58925 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 12 Sep 2016 17:13:59 +0100 Subject: iommu/dma: Add support for mapping MSIs When an MSI doorbell is located downstream of an IOMMU, attaching devices to a DMA ops domain and switching on translation leads to a rude shock when their attempt to write to the physical address returned by the irqchip driver faults (or worse, writes into some already-mapped buffer) and no interrupt is forthcoming. Address this by adding a hook for relevant irqchip drivers to call from their compose_msi_msg() callback, to swizzle the physical address with an appropriatly-mapped IOVA for any device attached to one of our DMA ops domains. Acked-by: Thomas Gleixner Acked-by: Marc Zyngier Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- include/linux/dma-iommu.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/dma-iommu.h') diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index 81c5c8d167ad..5ee806e41b5c 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -21,6 +21,7 @@ #ifdef CONFIG_IOMMU_DMA #include +#include int iommu_dma_init(void); @@ -62,9 +63,13 @@ void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int iommu_dma_supported(struct device *dev, u64 mask); int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr); +/* The DMA API isn't _quite_ the whole story, though... */ +void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg); + #else struct iommu_domain; +struct msi_msg; static inline int iommu_dma_init(void) { @@ -80,6 +85,10 @@ static inline void iommu_put_dma_cookie(struct iommu_domain *domain) { } +static inline void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg) +{ +} + #endif /* CONFIG_IOMMU_DMA */ #endif /* __KERNEL__ */ #endif /* __DMA_IOMMU_H */ -- cgit v1.2.3