iommu/amd: Add iommuv2 flag to struct amd_iommu

In mixed IOMMU setups this flag inidicates whether an IOMMU
supports the v2 features or not. This patch also adds a
global flag together with a function to query that flag from
other code. The flag shows if at least one IOMMUv2 is in the
system.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 2c25ae306e7c..d1e5067852d4 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -25,6 +25,7 @@
 #include <linux/interrupt.h>
 #include <linux/msi.h>
 #include <linux/amd-iommu.h>
+#include <linux/export.h>
 #include <asm/pci-direct.h>
 #include <asm/iommu.h>
 #include <asm/gart.h>
@@ -143,6 +144,8 @@ bool amd_iommu_iotlb_sup __read_mostly = true;
 
 u32 amd_iommu_max_pasids __read_mostly = ~0;
 
+bool amd_iommu_v2_present __read_mostly;
+
 /*
  * The ACPI table parsing functions set this variable on an error
  */
@@ -760,6 +763,12 @@ static void __init init_iommu_from_pci(struct amd_iommu *iommu)
 		amd_iommu_max_pasids = min(amd_iommu_max_pasids, pasids);
 	}
 
+	if (iommu_feature(iommu, FEATURE_GT) &&
+	    iommu_feature(iommu, FEATURE_PPR)) {
+		iommu->is_iommu_v2   = true;
+		amd_iommu_v2_present = true;
+	}
+
 	if (!is_rd890_iommu(iommu->dev))
 		return;
 
@@ -1645,3 +1654,9 @@ IOMMU_INIT_FINISH(amd_iommu_detect,
 		  gart_iommu_hole_init,
 		  0,
 		  0);
+
+bool amd_iommu_v2_supported(void)
+{
+	return amd_iommu_v2_present;
+}
+EXPORT_SYMBOL(amd_iommu_v2_supported);