diff options
Diffstat (limited to 'drivers/iommu/amd_iommu_init.c')
| -rw-r--r-- | drivers/iommu/amd_iommu_init.c | 13 |
1 files changed, 13 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; |