Commit c8238a31 authored Mar 04, 2015 by Mitchel Humpherys Committed by Matt Wagantall May 30, 2015

iommu/arm-smmu: zero out ptes completely on unmap

Thulium v1 has a hardware bug that requires us to zero out page table
entries completely rather than just setting the valid bits to 0. The
previous workaround for this [165066b85d: "iommu/arm-smmu: work around
transaction hardware bug"] was actually not quite right since it still
allowed the page frame number to be set in the page table entry. Fix
this by actually zero'ing out the pte.

Change-Id: I37537874ea4c5d1c00db7de65f70edd93ce63b90
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

parent 7839444b

drivers/iommu/arm-smmu.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1694,7 +1694,8 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_domain *smmu_domain,

		do {
		if (!(pteval & ARM_SMMU_PTE_PAGE))
		pteval = 0;
		*pte = 0;
		else
		*pte = pfn_pte(pfn, __pgprot(pteval));
		} while (pte++, pfn++, addr += PAGE_SIZE, --i);
		} while (addr != end);