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    SubjectRe: [PATCH v3 1/8] iommu: Add MMIO mapping type
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    Hi Niklas,

    Thank you for the patch.

    On Wednesday 10 February 2016 01:57:51 Niklas Söderlund wrote:
    > From: Robin Murphy <robin.murphy@arm.com>
    >
    > On some platforms, MMIO regions might need slightly different treatment
    > compared to mapping regular memory; add the notion of MMIO mappings to
    > the IOMMU API's memory type flags, so that callers can let the IOMMU
    > drivers know to do the right thing.
    >
    > Signed-off-by: Robin Murphy <robin.murphy@arm.com>
    > Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

    Answering the question from the cover letter, yes, it's totally fine to pick
    the ack, that's actually expected.

    > ---
    > drivers/iommu/io-pgtable-arm.c | 4 +++-
    > include/linux/iommu.h | 1 +

    You might be asked to split this patch in two.

    > 2 files changed, 4 insertions(+), 1 deletion(-)
    >
    > diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
    > index 381ca5a..3ff4f87 100644
    > --- a/drivers/iommu/io-pgtable-arm.c
    > +++ b/drivers/iommu/io-pgtable-arm.c
    > @@ -364,7 +364,9 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct
    > arm_lpae_io_pgtable *data, pte |= ARM_LPAE_PTE_HAP_READ;
    > if (prot & IOMMU_WRITE)
    > pte |= ARM_LPAE_PTE_HAP_WRITE;
    > - if (prot & IOMMU_CACHE)
    > + if (prot & IOMMU_MMIO)
    > + pte |= ARM_LPAE_PTE_MEMATTR_DEV;
    > + else if (prot & IOMMU_CACHE)
    > pte |= ARM_LPAE_PTE_MEMATTR_OIWB;
    > else
    > pte |= ARM_LPAE_PTE_MEMATTR_NC;
    > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
    > index a5c539f..34b6432 100644
    > --- a/include/linux/iommu.h
    > +++ b/include/linux/iommu.h
    > @@ -30,6 +30,7 @@
    > #define IOMMU_WRITE (1 << 1)
    > #define IOMMU_CACHE (1 << 2) /* DMA cache coherency */
    > #define IOMMU_NOEXEC (1 << 3)
    > +#define IOMMU_MMIO (1 << 4) /* e.g. things like MSI doorbells */
    >
    > struct iommu_ops;
    > struct iommu_group;

    --
    Regards,

    Laurent Pinchart

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