Introduce a new DOMAIN_ATTR_MSI_GEOMETRY domain attribute. It enables to query the aperture of the IOVA window dedicated to MSIs.
x86 IOMMUs will typically expose an MSI aperture matching the 1MB region [FEE0_0000h - FEF0_000h] corresponding to the APIC configuration space and no support for MSI translation. On ARM, arm-smmu(-v3) translate MSIs. Aperture is not set indicating MSI IOVA can live everywhere in the IOVA address space Signed-off-by: Eric Auger <[email protected]> Suggested-by: Alex Williamson <[email protected]> --- drivers/iommu/iommu.c | 5 +++++ include/linux/iommu.h | 13 +++++++++++++ 2 files changed, 18 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 9a2f196..617cb2b 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1485,6 +1485,7 @@ int iommu_domain_get_attr(struct iommu_domain *domain, enum iommu_attr attr, void *data) { struct iommu_domain_geometry *geometry; + struct iommu_domain_msi_geometry *msi_geometry; bool *paging; int ret = 0; u32 *count; @@ -1495,6 +1496,10 @@ int iommu_domain_get_attr(struct iommu_domain *domain, *geometry = domain->geometry; break; + case DOMAIN_ATTR_MSI_GEOMETRY: + msi_geometry = data; + *msi_geometry = domain->msi_geometry; + break; case DOMAIN_ATTR_PAGING: paging = data; *paging = (domain->pgsize_bitmap != 0UL); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 436dc21..ef6e047 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -52,6 +52,11 @@ struct iommu_domain_geometry { bool force_aperture; /* DMA only allowed in mappable range? */ }; +struct iommu_domain_msi_geometry { + dma_addr_t aperture_start; /* First address usable for MSI IOVA */ + dma_addr_t aperture_end; /* Last address usable for MSI IOVA */ +}; + /* Domain feature flags */ #define __IOMMU_DOMAIN_PAGING (1U << 0) /* Support for iommu_map/unmap */ #define __IOMMU_DOMAIN_DMA_API (1U << 1) /* Domain for use in DMA-API @@ -83,6 +88,7 @@ struct iommu_domain { iommu_fault_handler_t handler; void *handler_token; struct iommu_domain_geometry geometry; + struct iommu_domain_msi_geometry msi_geometry; void *iova_cookie; }; @@ -108,6 +114,7 @@ enum iommu_cap { enum iommu_attr { DOMAIN_ATTR_GEOMETRY, + DOMAIN_ATTR_MSI_GEOMETRY, DOMAIN_ATTR_PAGING, DOMAIN_ATTR_WINDOWS, DOMAIN_ATTR_FSL_PAMU_STASH, @@ -352,6 +359,12 @@ int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode, void iommu_fwspec_free(struct device *dev); int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids); +static inline bool iommu_domain_msi_aperture_valid(struct iommu_domain *domain) +{ + return (domain->msi_geometry.aperture_end > + domain->msi_geometry.aperture_start); +} + #else /* CONFIG_IOMMU_API */ struct iommu_ops {}; -- 1.9.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
