diff options
| author | Lu Baolu | 2019-03-20 09:58:33 +0800 |
|---|---|---|
| committer | Joerg Roedel | 2019-03-22 12:02:26 +0100 |
| commit | 5bb71fc790a88d063507dc5d445ab8b14e845591 (patch) | |
| tree | c21370e76c78b268cc3d3b00d9ccf3559d723d65 /drivers | |
| parent | 80ef4464d5e27408685e609d389663aad46644b9 (diff) | |
iommu/vt-d: Check capability before disabling protected memory
The spec states in 10.4.16 that the Protected Memory Enable
Register should be treated as read-only for implementations
not supporting protected memory regions (PLMR and PHMR fields
reported as Clear in the Capability register).
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: mark gross <mgross@intel.com>
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Fixes: f8bab73515ca5 ("intel-iommu: PMEN support")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 87274b54febd..f002d47d2f27 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1538,6 +1538,9 @@ static void iommu_disable_protect_mem_regions(struct intel_iommu *iommu) u32 pmen; unsigned long flags; + if (!cap_plmr(iommu->cap) && !cap_phmr(iommu->cap)) + return; + raw_spin_lock_irqsave(&iommu->register_lock, flags); pmen = readl(iommu->reg + DMAR_PMEN_REG); pmen &= ~DMA_PMEN_EPM; |