lkml.org 
[lkml]   [2016]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 1/8] iommu: Add MMIO mapping type
Date
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>
---
drivers/iommu/io-pgtable-arm.c | 4 +++-
include/linux/iommu.h | 1 +
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;
--
2.7.1
\
 
 \ /
  Last update: 2016-02-10 02:21    [W:0.145 / U:39.972 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site