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    SubjectRe: [GIT PULL] IOMMU fix for 5.10 (-final)
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    Hi All,

    On 12/10/20 1:50 AM, Will Deacon wrote:
    > On Wed, Dec 09, 2020 at 10:07:46AM -0800, Linus Torvalds wrote:
    >> On Wed, Dec 9, 2020 at 6:12 AM Will Deacon <will@kernel.org> wrote:
    >>>
    >>> Please pull this one-liner AMD IOMMU fix for 5.10. It's actually a fix
    >>> for a fix, where the size of the interrupt remapping table was increased
    >>> but a related constant for the size of the interrupt table was forgotten.
    >>
    >> Pulled.
    >
    > Thanks.
    >
    >> However, why didn't this then add some sanity checking for the two
    >> different #defines to be in sync?
    >>
    >> IOW, something like
    >>
    >> #define AMD_IOMMU_IRQ_TABLE_SHIFT 9
    >>
    >> #define MAX_IRQS_PER_TABLE (1 << AMD_IOMMU_IRQ_TABLE_SHIFT)
    >> #define DTE_IRQ_TABLE_LEN ((u64)AMD_IOMMU_IRQ_TABLE_SHIFT << 1)
    >>
    >> or whatever. Hmm?
    >
    > This looks like a worthwhile change to me, but I don't have any hardware
    > so I've been very reluctant to make even "obvious" driver changes here.
    >
    > Suravee -- please can you post a patch implementing the above?

    I'll send one out ASAP.

    >
    >> That way this won't happen again, but perhaps equally importantly the
    >> linkage will be more clear, and there won't be those random constants.
    >>
    >> Naming above is probably garbage - I assume there's some actual
    >> architectural name for that irq table length field in the DTE?
    >
    > The one in the spec is even better: "IntTabLen".
    >
    > Will

    Thanks,
    Suravee

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