iommu: Add MMIO mapping type

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: Joerg Roedel <jroedel@suse.de>

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index a5c539fa5d2bc03ba233f4d11de1b64d839990ab..34b643227df16ee41b19e7e2e70459268f9b1b2b 100644 (file)
--- 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;