From: Mario Limonciello <mario.limonciello@xxxxxxx> Bit 1 of the IVFS IVInfo field indicates that IOMMU has been used for pre-boot DMA protection. Export this capability to allow other places in the kernel to be able to check for it on AMD systems. Link: https://www.amd.com/system/files/TechDocs/48882_IOMMU.pdf Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> --- v4: Added to series from previous posting here: https://lore.kernel.org/linux-iommu/20220318223104.7049-1-mario.limonciello@xxxxxxx/ drivers/iommu/amd/amd_iommu_types.h | 4 ++++ drivers/iommu/amd/init.c | 3 +++ drivers/iommu/amd/iommu.c | 2 ++ 3 files changed, 9 insertions(+) diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h index 47108ed44fbb..72d0f5e2f651 100644 --- a/drivers/iommu/amd/amd_iommu_types.h +++ b/drivers/iommu/amd/amd_iommu_types.h @@ -407,6 +407,7 @@ /* IOMMU IVINFO */ #define IOMMU_IVINFO_OFFSET 36 #define IOMMU_IVINFO_EFRSUP BIT(0) +#define IOMMU_IVINFO_DMA_REMAP BIT(1) /* IOMMU Feature Reporting Field (for IVHD type 10h */ #define IOMMU_FEAT_GASUP_SHIFT 6 @@ -449,6 +450,9 @@ extern struct irq_remap_table **irq_lookup_table; /* Interrupt remapping feature used? */ extern bool amd_iommu_irq_remap; +/* IVRS indicates that pre-boot remapping was enabled */ +extern bool amdr_ivrs_remap_support; + /* kmem_cache to get tables with 128 byte alignement */ extern struct kmem_cache *amd_iommu_irq_cache; diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index b4a798c7b347..0467918bf7fd 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -182,6 +182,7 @@ u32 amd_iommu_max_pasid __read_mostly = ~0; bool amd_iommu_v2_present __read_mostly; static bool amd_iommu_pc_present __read_mostly; +bool amdr_ivrs_remap_support __read_mostly; bool amd_iommu_force_isolation __read_mostly; @@ -326,6 +327,8 @@ static void __init early_iommu_features_init(struct amd_iommu *iommu, { if (amd_iommu_ivinfo & IOMMU_IVINFO_EFRSUP) iommu->features = h->efr_reg; + if (amd_iommu_ivinfo & IOMMU_IVINFO_DMA_REMAP) + amdr_ivrs_remap_support = true; } /* Access to l1 and l2 indexed register spaces */ diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index e412a50dce59..81305c076de1 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2141,6 +2141,8 @@ static bool amd_iommu_capable(struct device *dev, enum iommu_cap cap) return (irq_remapping_enabled == 1); case IOMMU_CAP_NOEXEC: return false; + case IOMMU_CAP_PRE_BOOT_PROTECTION: + return amdr_ivrs_remap_support; default: break; } -- 2.28.0.dirty
