iommu: Make sure a device is always attached to a domain
Make use of the default domain and re-attach a device to it
when it is detached from another domain. Also enforce that a
device has to be in the default domain before it can be
attached to a different domain.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index ef73923..7bce522 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -52,6 +52,7 @@
char *name;
int id;
struct iommu_domain *default_domain;
+ struct iommu_domain *domain;
};
struct iommu_device {
@@ -78,6 +79,12 @@
static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
unsigned type);
+static int __iommu_attach_device(struct iommu_domain *domain,
+ struct device *dev);
+static int __iommu_attach_group(struct iommu_domain *domain,
+ struct iommu_group *group);
+static void __iommu_detach_group(struct iommu_domain *domain,
+ struct iommu_group *group);
static ssize_t iommu_group_attr_show(struct kobject *kobj,
struct attribute *__attr, char *buf)
@@ -376,6 +383,8 @@
mutex_lock(&group->mutex);
list_add_tail(&device->list, &group->devices);
+ if (group->domain)
+ __iommu_attach_device(group->domain, dev);
mutex_unlock(&group->mutex);
/* Notify any listeners about change to group. */
@@ -455,19 +464,30 @@
* The group->mutex is held across callbacks, which will block calls to
* iommu_group_add/remove_device.
*/
-int iommu_group_for_each_dev(struct iommu_group *group, void *data,
- int (*fn)(struct device *, void *))
+static int __iommu_group_for_each_dev(struct iommu_group *group, void *data,
+ int (*fn)(struct device *, void *))
{
struct iommu_device *device;
int ret = 0;
- mutex_lock(&group->mutex);
list_for_each_entry(device, &group->devices, list) {
ret = fn(device->dev, data);
if (ret)
break;
}
+ return ret;
+}
+
+
+int iommu_group_for_each_dev(struct iommu_group *group, void *data,
+ int (*fn)(struct device *, void *))
+{
+ int ret;
+
+ mutex_lock(&group->mutex);
+ ret = __iommu_group_for_each_dev(group, data, fn);
mutex_unlock(&group->mutex);
+
return ret;
}
EXPORT_SYMBOL_GPL(iommu_group_for_each_dev);
@@ -727,6 +747,7 @@
*/
group->default_domain = __iommu_domain_alloc(pdev->dev.bus,
IOMMU_DOMAIN_DMA);
+ group->domain = group->default_domain;
}
return group;
@@ -1012,7 +1033,7 @@
if (iommu_group_device_count(group) != 1)
goto out_unlock;
- ret = __iommu_attach_device(domain, dev);
+ ret = __iommu_attach_group(domain, group);
out_unlock:
mutex_unlock(&group->mutex);
@@ -1047,7 +1068,7 @@
goto out_unlock;
}
- __iommu_detach_device(domain, dev);
+ __iommu_detach_group(domain, group);
out_unlock:
mutex_unlock(&group->mutex);
@@ -1072,10 +1093,31 @@
return __iommu_attach_device(domain, dev);
}
+static int __iommu_attach_group(struct iommu_domain *domain,
+ struct iommu_group *group)
+{
+ int ret;
+
+ if (group->default_domain && group->domain != group->default_domain)
+ return -EBUSY;
+
+ ret = __iommu_group_for_each_dev(group, domain,
+ iommu_group_do_attach_device);
+ if (ret == 0)
+ group->domain = domain;
+
+ return ret;
+}
+
int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)
{
- return iommu_group_for_each_dev(group, domain,
- iommu_group_do_attach_device);
+ int ret;
+
+ mutex_lock(&group->mutex);
+ ret = __iommu_attach_group(domain, group);
+ mutex_unlock(&group->mutex);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(iommu_attach_group);
@@ -1088,9 +1130,35 @@
return 0;
}
+static void __iommu_detach_group(struct iommu_domain *domain,
+ struct iommu_group *group)
+{
+ int ret;
+
+ if (!group->default_domain) {
+ __iommu_group_for_each_dev(group, domain,
+ iommu_group_do_detach_device);
+ group->domain = NULL;
+ return;
+ }
+
+ if (group->domain == group->default_domain)
+ return;
+
+ /* Detach by re-attaching to the default domain */
+ ret = __iommu_group_for_each_dev(group, group->default_domain,
+ iommu_group_do_attach_device);
+ if (ret != 0)
+ WARN_ON(1);
+ else
+ group->domain = group->default_domain;
+}
+
void iommu_detach_group(struct iommu_domain *domain, struct iommu_group *group)
{
- iommu_group_for_each_dev(group, domain, iommu_group_do_detach_device);
+ mutex_lock(&group->mutex);
+ __iommu_detach_group(domain, group);
+ mutex_unlock(&group->mutex);
}
EXPORT_SYMBOL_GPL(iommu_detach_group);