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Commit 5bb71fc7 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

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: default avatarAshok Raj <ashok.raj@intel.com>
Fixes: f8bab735 ("intel-iommu: PMEN support")
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 80ef4464

drivers/iommu/intel-iommu.c

+3 −0
Original line number Diff line number Diff line
@@ -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;