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| author |   Lu Baolu <baolu.lu@linux.intel.com> | 2019-03-20 09:58:33 +0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-20 09:17:02 +0200 |
| commit | d965161274983e34caf8f38af287f0a1e2adbb27 (patch) | |
| tree | 10775d6fe0eee7ba1a5074355031390c8e82cb05 | |
| parent | d9fb98c921a89a178cfa36c8efcb675493644314 (diff) | |
| download | linux-yocto-d965161274983e34caf8f38af287f0a1e2adbb27.tar.gz linux-yocto-d965161274983e34caf8f38af287f0a1e2adbb27.tar.bz2 linux-yocto-d965161274983e34caf8f38af287f0a1e2adbb27.zip | |
iommu/vt-d: Check capability before disabling protected memory
[ Upstream commit 5bb71fc790a88d063507dc5d445ab8b14e845591 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 dbd6824dfffa..68a21c49c562 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1534,6 +1534,9 @@ 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; |