iommu: Limit iommu_attach/detach_device to devices with their own group
This patch changes the behavior of the iommu_attach_device
and iommu_detach_device functions. With this change these
functions only work on devices that have their own group.
For all other devices the iommu_group_attach/detach
functions must be used.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 49eb9bf..ef73923 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -433,6 +433,17 @@
}
EXPORT_SYMBOL_GPL(iommu_group_remove_device);
+static int iommu_group_device_count(struct iommu_group *group)
+{
+ struct iommu_device *entry;
+ int ret = 0;
+
+ list_for_each_entry(entry, &group->devices, list)
+ ret++;
+
+ return ret;
+}
+
/**
* iommu_group_for_each_dev - iterate over each device in the group
* @group: the group
@@ -969,7 +980,8 @@
}
EXPORT_SYMBOL_GPL(iommu_domain_free);
-int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
+static int __iommu_attach_device(struct iommu_domain *domain,
+ struct device *dev)
{
int ret;
if (unlikely(domain->ops->attach_dev == NULL))
@@ -980,9 +992,38 @@
trace_attach_device_to_domain(dev);
return ret;
}
+
+int iommu_attach_device(struct iommu_domain *domain, struct device *dev)
+{
+ struct iommu_group *group;
+ int ret;
+
+ group = iommu_group_get(dev);
+ /* FIXME: Remove this when groups a mandatory for iommu drivers */
+ if (group == NULL)
+ return __iommu_attach_device(domain, dev);
+
+ /*
+ * We have a group - lock it to make sure the device-count doesn't
+ * change while we are attaching
+ */
+ mutex_lock(&group->mutex);
+ ret = -EINVAL;
+ if (iommu_group_device_count(group) != 1)
+ goto out_unlock;
+
+ ret = __iommu_attach_device(domain, dev);
+
+out_unlock:
+ mutex_unlock(&group->mutex);
+ iommu_group_put(group);
+
+ return ret;
+}
EXPORT_SYMBOL_GPL(iommu_attach_device);
-void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
+static void __iommu_detach_device(struct iommu_domain *domain,
+ struct device *dev)
{
if (unlikely(domain->ops->detach_dev == NULL))
return;
@@ -990,6 +1031,28 @@
domain->ops->detach_dev(domain, dev);
trace_detach_device_from_domain(dev);
}
+
+void iommu_detach_device(struct iommu_domain *domain, struct device *dev)
+{
+ struct iommu_group *group;
+
+ group = iommu_group_get(dev);
+ /* FIXME: Remove this when groups a mandatory for iommu drivers */
+ if (group == NULL)
+ return __iommu_detach_device(domain, dev);
+
+ mutex_lock(&group->mutex);
+ if (iommu_group_device_count(group) != 1) {
+ WARN_ON(1);
+ goto out_unlock;
+ }
+
+ __iommu_detach_device(domain, dev);
+
+out_unlock:
+ mutex_unlock(&group->mutex);
+ iommu_group_put(group);
+}
EXPORT_SYMBOL_GPL(iommu_detach_device);
/*
@@ -1006,7 +1069,7 @@
{
struct iommu_domain *domain = data;
- return iommu_attach_device(domain, dev);
+ return __iommu_attach_device(domain, dev);
}
int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)
@@ -1020,7 +1083,7 @@
{
struct iommu_domain *domain = data;
- iommu_detach_device(domain, dev);
+ __iommu_detach_device(domain, dev);
return 0;
}