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SubjectRe: [PATCH v3 1/8] iommu: Add MMIO mapping type
Date
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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