[PATCH 06/22] iommu: Allocate a default domain for iommu groups

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

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

The default domain will be used (if supported by the iommu
driver) when the devices in the iommu group are not attached
to any other domain.

Signed-off-by: Joerg Roedel <jroedel-l3A5Bk7waGM@public.gmane.org>
---
 drivers/iommu/iommu.c | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d69e0ca..fbfc015 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -51,6 +51,7 @@ struct iommu_group {
 	void (*iommu_data_release)(void *iommu_data);
 	char *name;
 	int id;
+	struct iommu_domain *default_domain;
 };
 
 struct iommu_device {
@@ -75,6 +76,9 @@ struct iommu_group_attribute iommu_group_attr_##_name =		\
 #define to_iommu_group(_kobj)		\
 	container_of(_kobj, struct iommu_group, kobj)
 
+static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
+						 unsigned type);
+
 static ssize_t iommu_group_attr_show(struct kobject *kobj,
 				     struct attribute *__attr, char *buf)
 {
@@ -137,6 +141,9 @@ static void iommu_group_release(struct kobject *kobj)
 	ida_remove(&iommu_group_ida, group->id);
 	mutex_unlock(&iommu_group_mutex);
 
+	if (group->default_domain)
+		iommu_domain_free(group->default_domain);
+
 	kfree(group->name);
 	kfree(group);
 }
@@ -701,7 +708,18 @@ static struct iommu_group *iommu_group_get_for_pci_dev(struct pci_dev *pdev)
 		return group;
 
 	/* No shared group found, allocate new */
-	return iommu_group_alloc();
+	group = iommu_group_alloc();
+	if (group) {
+		/*
+		 * Try to allocate a default domain - needs support from the
+		 * IOMMU driver.
+		 */
+		group->default_domain = __iommu_domain_alloc(pdev->dev.bus,
+							     IOMMU_DOMAIN_DMA);
+		group->domain = group->default_domain;
+	}
+
+	return group;
 }
 
 /**
@@ -922,22 +940,28 @@ void iommu_set_fault_handler(struct iommu_domain *domain,
 }
 EXPORT_SYMBOL_GPL(iommu_set_fault_handler);
 
-struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
+static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
+						 unsigned type)
 {
 	struct iommu_domain *domain;
 
 	if (bus == NULL || bus->iommu_ops == NULL)
 		return NULL;
 
-	domain = bus->iommu_ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED);
+	domain = bus->iommu_ops->domain_alloc(type);
 	if (!domain)
 		return NULL;
 
 	domain->ops  = bus->iommu_ops;
-	domain->type = IOMMU_DOMAIN_UNMANAGED;
+	domain->type = type;
 
 	return domain;
 }
+
+struct iommu_domain *iommu_domain_alloc(struct bus_type *bus)
+{
+	return __iommu_domain_alloc(bus, IOMMU_DOMAIN_UNMANAGED);
+}
 EXPORT_SYMBOL_GPL(iommu_domain_alloc);
 
 void iommu_domain_free(struct iommu_domain *domain)
-- 
1.9.1