[PATCH v3 1/8] iommu: Add MMIO mapping type
From: niklas.soderlund@ragnatech.se (Niklas Söderlund)
Date: 2016-02-16 12:06:35
Also in:
linux-arch, linux-iommu, linux-renesas-soc, lkml
Hi Robin, Thanks for your update patch I will include it in my next version. But I'm sorry I do not understand, is your modification an addition or a substitution to your original patch? * Robin Murphy [off-list ref] [2016-02-11 15:57:26 +0000]:
quoted hunk ↗ jump to hunk
On 11/02/16 00:02, Laurent Pinchart wrote:quoted
Hi Niklas, Thank you for the patch. On Wednesday 10 February 2016 01:57:51 Niklas S?derlund wrote:quoted
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.quoted
--- drivers/iommu/io-pgtable-arm.c | 4 +++- include/linux/iommu.h | 1 +You might be asked to split this patch in two.Worse than that, you might also be asked to fix it up when the silly author remembers that he did this on a stage-2-only ARM SMMU, and the attributes for the stage 1 tables that the IPMMU uses are in a different code path: --->8---diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 5b5c299..7622c6e 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c@@ -354,7 +354,10 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(structarm_lpae_io_pgtable *data, if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ)) pte |= ARM_LPAE_PTE_AP_RDONLY; - if (prot & IOMMU_CACHE) + if (prot & IOMMU_MMIO) + pte |= (ARM_LPAE_MAIR_ATTR_IDX_DEV + << ARM_LPAE_PTE_ATTRINDX_SHIFT); + else if (prot & IOMMU_CACHE) pte |= (ARM_LPAE_MAIR_ATTR_IDX_CACHE << ARM_LPAE_PTE_ATTRINDX_SHIFT); } else { --->8--- Sorry for the bother, Robin.quoted
quoted
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;