| From | Ben Hutchings <> | Date | Sat, 10 Aug 2019 21:40:07 +0100 | Subject | [PATCH 3.16 038/157] iommu/vt-d: Check capability before disabling protected memory |
| |
3.16.72-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Lu Baolu <baolu.lu@linux.intel.com>
commit 5bb71fc790a88d063507dc5d445ab8b14e845591 upstream.
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: Ben Hutchings <ben@decadent.org.uk> --- drivers/iommu/intel-iommu.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1394,6 +1394,9 @@ static void iommu_disable_protect_mem_re 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;
|