iommu: Introduce iommu domain types
This allows to handle domains differently based on their
type in the future. An IOMMU driver can implement certain
optimizations for DMA-API domains for example.
The domain types can be extended later and some of the
existing domain attributes can be migrated to become domain
flags.
Tested-by: Thierry Reding <treding@nvidia.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 69d1d12..72d03fe 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -51,7 +51,32 @@
bool force_aperture; /* DMA only allowed in mappable range? */
};
+/* Domain feature flags */
+#define __IOMMU_DOMAIN_PAGING (1U << 0) /* Support for iommu_map/unmap */
+#define __IOMMU_DOMAIN_DMA_API (1U << 1) /* Domain for use in DMA-API
+ implementation */
+#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */
+
+/*
+ * This are the possible domain-types
+ *
+ * IOMMU_DOMAIN_BLOCKED - All DMA is blocked, can be used to isolate
+ * devices
+ * IOMMU_DOMAIN_IDENTITY - DMA addresses are system physical addresses
+ * IOMMU_DOMAIN_UNMANAGED - DMA mappings managed by IOMMU-API user, used
+ * for VMs
+ * IOMMU_DOMAIN_DMA - Internally used for DMA-API implementations.
+ * This flag allows IOMMU drivers to implement
+ * certain optimizations for these domains
+ */
+#define IOMMU_DOMAIN_BLOCKED (0U)
+#define IOMMU_DOMAIN_IDENTITY (__IOMMU_DOMAIN_PT)
+#define IOMMU_DOMAIN_UNMANAGED (__IOMMU_DOMAIN_PAGING)
+#define IOMMU_DOMAIN_DMA (__IOMMU_DOMAIN_PAGING | \
+ __IOMMU_DOMAIN_DMA_API)
+
struct iommu_domain {
+ unsigned type;
const struct iommu_ops *ops;
void *priv;
iommu_fault_handler_t handler;
@@ -117,7 +142,7 @@
void (*domain_destroy)(struct iommu_domain *domain);
/* Domain allocation and freeing by the iommu driver */
- struct iommu_domain *(*domain_alloc)(void);
+ struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type);
void (*domain_free)(struct iommu_domain *);
int (*attach_dev)(struct iommu_domain *domain, struct device *dev);