Commit 9113785c authored by Russell King's avatar Russell King Committed by Thierry Reding

iommu/tegra-smmu: Fix iova_to_phys() method

iova_to_phys() has several problems:
(a) iova_to_phys() is supposed to return 0 if there is no entry present
    for the iova.
(b) if as_get_pte() fails, we oops the kernel by dereferencing a NULL
    pointer.  Really, we should not even be trying to allocate a page
    table at all, but should only be returning the presence of the 2nd
    level page table.  This will be fixed in a subsequent patch.

Treat both of these conditions as "no mapping" conditions.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
parent d770e558
...@@ -592,6 +592,9 @@ static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain, ...@@ -592,6 +592,9 @@ static phys_addr_t tegra_smmu_iova_to_phys(struct iommu_domain *domain,
u32 *pte; u32 *pte;
pte = as_get_pte(as, iova, &page); pte = as_get_pte(as, iova, &page);
if (!pte || !*pte)
return 0;
pfn = *pte & as->smmu->pfn_mask; pfn = *pte & as->smmu->pfn_mask;
return PFN_PHYS(pfn); return PFN_PHYS(pfn);
......
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