From 4a20ce0ff68eb6fc4b1e8f25139c93b312f21229 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 4 May 2023 22:10:55 +0100 Subject: iommu: Add a capability for flush queue support Passing a special type to domain_alloc to indirectly query whether flush queues are a worthwhile optimisation with the given driver is a bit clunky, and looking increasingly anachronistic. Let's put that into an explicit capability instead. Signed-off-by: Robin Murphy Reviewed-by: Lu Baolu Tested-by: Jerry Snitselaar # amd, intel, smmu-v3 Reviewed-by: Jerry Snitselaar Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/f0086a93dbccb92622e1ace775846d81c1c4b174.1683233867.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index e8c9a7da1060..1b7180d6edae 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -127,6 +127,11 @@ enum iommu_cap { * this device. */ IOMMU_CAP_ENFORCE_CACHE_COHERENCY, + /* + * IOMMU driver does not issue TLB maintenance during .unmap, so can + * usefully support the non-strict DMA flush queue. + */ + IOMMU_CAP_DEFERRED_FLUSH, }; /* These are the possible reserved region types */ -- cgit v1.2.3 From a4fdd976227240b06ced89b5df88a1a1f388f092 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 4 May 2023 22:10:56 +0100 Subject: iommu: Use flush queue capability It remains really handy to have distinct DMA domain types within core code for the sake of default domain policy selection, but we can now hide that detail from drivers by using the new capability instead. Signed-off-by: Robin Murphy Tested-by: Jerry Snitselaar # amd, intel, smmu-v3 Reviewed-by: Jerry Snitselaar Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/1c552d99e8ba452bdac48209fa74c0bdd52fd9d9.1683233867.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel --- include/linux/iommu.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 1b7180d6edae..d31642596675 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -65,6 +65,7 @@ struct iommu_domain_geometry { #define __IOMMU_DOMAIN_SVA (1U << 4) /* Shared process address space */ +#define IOMMU_DOMAIN_ALLOC_FLAGS ~__IOMMU_DOMAIN_DMA_FQ /* * This are the possible domain-types * -- cgit v1.2.3