[PATCH v3 1/8] iommu: Add MMIO mapping type
From: laurent.pinchart@ideasonboard.com (Laurent Pinchart)
Date: 2016-02-11 00:01:51
Also in:
linux-arch, linux-iommu, linux-renesas-soc, lkml
Hi Niklas, Thank you for the patch. On Wednesday 10 February 2016 01:57:51 Niklas S?derlund 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.
quoted hunk ↗ jump to hunk
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(structarm_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