[PATCH 02/15] iommu: Introduce iommu domain types

[Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>]

From: Joerg Roedel <jroedel-l3A5Bk7waGM@public.gmane.org>

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.

Signed-off-by: Joerg Roedel <jroedel-l3A5Bk7waGM@public.gmane.org>
---
 drivers/iommu/iommu.c |  5 +++--
 include/linux/iommu.h | 11 ++++++++++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 684efc0..ab24d77 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -909,14 +909,15 @@ struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
 	ops = bus->iommu_ops;
 
 	if (ops->domain_alloc)
-		domain = ops->domain_alloc();
+		domain = ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED);
 	else
 		domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 
 	if (!domain)
 		return NULL;
 
-	domain->ops = bus->iommu_ops;
+	domain->ops  = bus->iommu_ops;
+	domain->type = IOMMU_DOMAIN_UNMANAGED;
 
 	if (ops->domain_init && domain->ops->domain_init(domain))
 		goto out_free;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 69d1d12..0b67f65 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -51,7 +51,16 @@ struct iommu_domain_geometry {
 	bool force_aperture;       /* DMA only allowed in mappable range? */
 };
 
+/* This are the possible domain-types */
+enum iommu_domain_type {
+	IOMMU_DOMAIN_DMA,	/* Domain used for DMA-API */
+	IOMMU_DOMAIN_IDENTITY,	/* Identity mapped domain  */
+	IOMMU_DOMAIN_UNMANAGED, /* Domain mappings are managed by a third party
+				   user (like KVM or VFIO) */
+};
+
 struct iommu_domain {
+	enum iommu_domain_type type;
 	const struct iommu_ops *ops;
 	void *priv;
 	iommu_fault_handler_t handler;
@@ -117,7 +126,7 @@ struct iommu_ops {
 	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)(enum iommu_domain_type);
 	void (*domain_free)(struct iommu_domain *);
 
 	int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
-- 
1.8.4.5