• Robin Murphy's avatar
    iommu/io-pgtable-arm-v7s: Fix attributes when splitting blocks · e633fc7a
    Robin Murphy authored
    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: e5fc9753 ("iommu/io-pgtable: Add ARMv7 short descriptor support")
    Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    e633fc7a
io-pgtable-arm-v7s.c 23.5 KB