From a919a018cccf999aa56d7f9adeae0525b01b7434 Mon Sep 17 00:00:00 2001 From: Suravee Suthikulpanit Date: Wed, 5 Mar 2014 18:54:18 -0600 Subject: iommu/amd: Fix logic to determine and checking max PASID In reality, the spec can only support 16-bit PASID since INVALIDATE_IOTLB_PAGES and COMPLETE_PPR_REQUEST commands only allow 16-bit PASID. So, we updated the PASID_MASK accordingly and invoke BUG_ON if the hardware is reporting PASmax more than 16-bit. Besides, max PASID is defined as ((2^(PASmax+1)) - 1). The current does not determine this correctly. Signed-off-by: Suravee Suthikulpanit Tested-by: Jay Cornwall Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu_init.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) (limited to 'drivers/iommu/amd_iommu_init.c') diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index 28b4bea..b76c58d 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -150,7 +150,7 @@ 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; +u32 amd_iommu_max_pasid __read_mostly = ~0; bool amd_iommu_v2_present __read_mostly; bool amd_iommu_pc_present __read_mostly; @@ -1231,14 +1231,16 @@ static int iommu_init_pci(struct amd_iommu *iommu) if (iommu_feature(iommu, FEATURE_GT)) { int glxval; - u32 pasids; - u64 shift; + u32 max_pasid; + u64 pasmax; - shift = iommu->features & FEATURE_PASID_MASK; - shift >>= FEATURE_PASID_SHIFT; - pasids = (1 << shift); + pasmax = iommu->features & FEATURE_PASID_MASK; + pasmax >>= FEATURE_PASID_SHIFT; + max_pasid = (1 << (pasmax + 1)) - 1; - amd_iommu_max_pasids = min(amd_iommu_max_pasids, pasids); + amd_iommu_max_pasid = min(amd_iommu_max_pasid, max_pasid); + + BUG_ON(amd_iommu_max_pasid & ~PASID_MASK); glxval = iommu->features & FEATURE_GLXVAL_MASK; glxval >>= FEATURE_GLXVAL_SHIFT; -- cgit v1.1