From ece6e6f0218b7777e650bf93728130ae6f4feb7d Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Wed, 1 May 2019 14:58:19 +0100 Subject: iommu/dma-iommu: Split iommu_dma_map_msi_msg() in two parts On RT, iommu_dma_map_msi_msg() may be called from non-preemptible context. This will lead to a splat with CONFIG_DEBUG_ATOMIC_SLEEP as the function is using spin_lock (they can sleep on RT). iommu_dma_map_msi_msg() is used to map the MSI page in the IOMMU PT and update the MSI message with the IOVA. Only the part to lookup for the MSI page requires to be called in preemptible context. As the MSI page cannot change over the lifecycle of the MSI interrupt, the lookup can be cached and re-used later on. iomma_dma_map_msi_msg() is now split in two functions: - iommu_dma_prepare_msi(): This function will prepare the mapping in the IOMMU and store the cookie in the structure msi_desc. This function should be called in preemptible context. - iommu_dma_compose_msi_msg(): This function will update the MSI message with the IOVA when the device is behind an IOMMU. Signed-off-by: Julien Grall Reviewed-by: Robin Murphy Reviewed-by: Eric Auger Acked-by: Joerg Roedel Signed-off-by: Marc Zyngier --- drivers/iommu/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/iommu/Kconfig') diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 6f07f3b21816..eb1c8cd243f9 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -94,6 +94,7 @@ config IOMMU_DMA bool select IOMMU_API select IOMMU_IOVA + select IRQ_MSI_IOMMU select NEED_SG_DMA_LENGTH config FSL_PAMU -- cgit v1.2.3-70-g09d2