From: Mario Limonciello <mario.limonciello@amd.com>
Date: Mon, 25 Apr 2022 13:42:05 +0100
Subject: iommu/amd: Indicate whether DMA remap support is enabled
Git-commit: f1ca70717bcb4525e29da422f3d280acbddb36fe
Patch-mainline: v5.19-rc1
References: bsc#1205701
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
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/ce7627fa1c596878ca6515dd9d4381a45b6ee38c.1650878781.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
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 079694f894b8..038e104b922c 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2155,6 +2155,8 @@ static bool amd_iommu_capable(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;
}