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Groups > linux.kernel > #1352578

[PATCH v5 1/9] iommu: Add MMIO mapping type

From Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Newsgroups linux.kernel
Subject [PATCH v5 1/9] iommu: Add MMIO mapping type
Date 2016-03-08 03:50 +0100
Message-ID <rafSG-34S-25@gated-at.bofh.it> (permalink)
References <rafSF-34S-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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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>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
---
 drivers/iommu/io-pgtable-arm.c | 9 +++++++--
 include/linux/iommu.h          | 1 +
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 381ca5a..9c19989 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -355,7 +355,10 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_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 {
@@ -364,7 +367,9 @@ 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;
-- 
2.7.2

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Thread

[PATCH v5 0/9] dmaengine: rcar-dmac: add iommu support for slave transfers Niklas Söderlund   <niklas.soderlund+renesas@ragnatech.se> - 2016-03-08 03:50 +0100
  [PATCH v5 4/9] arm: dma-mapping: add {map,unmap}_resource for iommu ops Niklas Söderlund   <niklas.soderlund+renesas@ragnatech.se> - 2016-03-08 03:50 +0100
  [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Niklas Söderlund   <niklas.soderlund+renesas@ragnatech.se> - 2016-03-08 03:50 +0100
    Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Christoph Hellwig <hch@infradead.org> - 2016-03-08 08:40 +0100
      Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource "Niklas S??derlund" <niklas.soderlund@ragnatech.se> - 2016-03-10 17:10 +0100
        Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Vinod Koul <vinod.koul@intel.com> - 2016-03-11 07:20 +0100
        Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Dan Williams <dan.j.williams@intel.com> - 2016-03-11 07:50 +0100
          Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Christoph Hellwig <hch@infradead.org> - 2016-03-11 12:20 +0100
            Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Niklas Söderlund   <niklas.soderlund@ragnatech.se> - 2016-03-11 14:00 +0100
              Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Christoph Hellwig <hch@infradead.org> - 2016-03-15 09:30 +0100
          Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Robin Murphy <robin.murphy@arm.com> - 2016-03-11 14:50 +0100
            Re: [PATCH v5 3/9] dma-mapping: add dma_{map,unmap}_resource Dan Williams <dan.j.williams@intel.com> - 2016-03-11 19:00 +0100
  [PATCH v5 9/9] ARM: dts: r8a7791: add iommus to dmac0 and dmac1 Niklas Söderlund   <niklas.soderlund+renesas@ragnatech.se> - 2016-03-08 03:50 +0100
  [PATCH v5 1/9] iommu: Add MMIO mapping type Niklas Söderlund   <niklas.soderlund+renesas@ragnatech.se> - 2016-03-08 03:50 +0100
  [PATCH v5 6/9] dmaengine: rcar-dmac: group slave configuration Niklas Söderlund   <niklas.soderlund+renesas@ragnatech.se> - 2016-03-08 03:50 +0100

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