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-rw-r--r--drivers/iommu/amd_iommu_init.c13
-rw-r--r--drivers/iommu/amd_iommu_types.h6
2 files changed, 19 insertions, 0 deletions
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 17e0f77c7dad..fb4afd6d357d 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -141,6 +141,8 @@ int amd_iommus_present;
bool amd_iommu_np_cache __read_mostly;
bool amd_iommu_iotlb_sup __read_mostly = true;
+u32 amd_iommu_max_pasids __read_mostly = ~0;
+
/*
* The ACPI table parsing functions set this variable on an error
*/
@@ -699,6 +701,17 @@ static void __init init_iommu_from_pci(struct amd_iommu *iommu)
iommu->features = ((u64)high << 32) | low;
+ if (iommu_feature(iommu, FEATURE_GT)) {
+ u32 pasids;
+ u64 shift;
+
+ shift = iommu->features & FEATURE_PASID_MASK;
+ shift >>= FEATURE_PASID_SHIFT;
+ pasids = (1 << shift);
+
+ amd_iommu_max_pasids = min(amd_iommu_max_pasids, pasids);
+ }
+
if (!is_rd890_iommu(iommu->dev))
return;
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index f8dd9ae693d1..0d984ca925be 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -87,6 +87,9 @@
#define FEATURE_HE (1ULL<<8)
#define FEATURE_PC (1ULL<<9)
+#define FEATURE_PASID_SHIFT 32
+#define FEATURE_PASID_MASK (0x1fULL << FEATURE_PASID_SHIFT)
+
/* MMIO status bits */
#define MMIO_STATUS_COM_WAIT_INT_MASK 0x04
@@ -549,6 +552,9 @@ extern unsigned long *amd_iommu_pd_alloc_bitmap;
*/
extern bool amd_iommu_unmap_flush;
+/* Smallest number of PASIDs supported by any IOMMU in the system */
+extern u32 amd_iommu_max_pasids;
+
/* takes bus and device/function and returns the device id
* FIXME: should that be in generic PCI code? */
static inline u16 calc_devid(u8 bus, u8 devfn)