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authorRobin Murphy <robin.murphy@arm.com>2016-08-11 17:44:05 +0100
committerWill Deacon <will.deacon@arm.com>2016-08-19 09:40:16 +0100
commite633fc7a1347528c3b4a6bbdeb41f5d63988242c (patch)
treecd7ad5a5779d4bcb65d2d90c88a891b532f7dcbe /drivers/iommu
parent694d0d0bb2030d2e36df73e2d23d5770511dbc8d (diff)
downloadlinux-e633fc7a1347528c3b4a6bbdeb41f5d63988242c.tar.bz2
iommu/io-pgtable-arm-v7s: Fix attributes when splitting blocks
Due to the attribute bits being all over the place in the different types of short-descriptor PTEs, when remapping an existing entry, e.g. splitting a section into pages, we take the approach of decomposing the PTE attributes back to the IOMMU API flags to start from scratch. On inspection, though, the existing code seems to have got the read-only bit backwards and ignored the XN bit. How embarrassing... Fortunately the primary user so far, the Mediatek IOMMU, both never splits blocks (because it only serves non-overlapping DMA API calls) and also ignores permissions anyway, but let's put things right before any future users trip up. Cc: <stable@vger.kernel.org> Fixes: e5fc9753b1a8 ("iommu/io-pgtable: Add ARMv7 short descriptor support") Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/io-pgtable-arm-v7s.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index 8c6139986d7d..def8ca1c982d 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -286,12 +286,14 @@ static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl)
int prot = IOMMU_READ;
arm_v7s_iopte attr = pte >> ARM_V7S_ATTR_SHIFT(lvl);
- if (attr & ARM_V7S_PTE_AP_RDONLY)
+ if (!(attr & ARM_V7S_PTE_AP_RDONLY))
prot |= IOMMU_WRITE;
if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0)
prot |= IOMMU_MMIO;
else if (pte & ARM_V7S_ATTR_C)
prot |= IOMMU_CACHE;
+ if (pte & ARM_V7S_ATTR_XN(lvl))
+ prot |= IOMMU_NOEXEC;
return prot;
}