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    SubjectRe: [PATCH kernel v8 09/31] powerpc/powernv: Do not set "read" flag if direction==DMA_NONE
    On Fri, Apr 10, 2015 at 04:30:51PM +1000, Alexey Kardashevskiy wrote:
    > Normally a bitmap from the iommu_table is used to track what TCE entry
    > is in use. Since we are going to use iommu_table without its locks and
    > do xchg() instead, it becomes essential not to put bits which are not
    > implied in the direction flag.

    It's not clear to me from this why lack of locking implies the need to
    not put extra bits in.

    > This adds iommu_direction_to_tce_perm() (its counterpart is there already)
    > and uses it for powernv's pnv_tce_build().
    >
    > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

    I have no objection to the patch though, so

    Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

    --
    David Gibson | I'll have my music baroque, and my code
    david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
    | _way_ _around_!
    http://www.ozlabs.org/~dgibson
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