[PATCH 3/8] iommu: Factor out a "first device in group" helper

[Robin Murphy]

This pattern for picking the first device out of the group list is
repeated a few times now, so it's clearly worth factoring out.

Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
 drivers/iommu/iommu.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index bc53ffbba4de..5b37766a09e2 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1084,6 +1084,11 @@ void iommu_group_remove_device(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(iommu_group_remove_device);
 
+static struct device *iommu_group_first_dev(struct iommu_group *group)
+{
+	return list_first_entry(&group->devices, struct group_device, list)->dev;
+}
+
 static int iommu_group_device_count(struct iommu_group *group)
 {
 	struct group_device *entry;
@@ -2835,7 +2840,6 @@ static int iommu_change_dev_def_domain(struct iommu_group *group,
 				       struct device *prev_dev, int type)
 {
 	struct iommu_domain *prev_dom;
-	struct group_device *grp_dev;
 	int ret, dev_def_dom;
 	struct device *dev;
 
@@ -2867,8 +2871,7 @@ static int iommu_change_dev_def_domain(struct iommu_group *group,
 	}
 
 	/* Since group has only one device */
-	grp_dev = list_first_entry(&group->devices, struct group_device, list);
-	dev = grp_dev->dev;
+	dev = iommu_group_first_dev(group);
 
 	if (prev_dev != dev) {
 		dev_err_ratelimited(prev_dev, "Cannot change default domain: Device has been changed\n");
@@ -2965,7 +2968,6 @@ static int iommu_change_dev_def_domain(struct iommu_group *group,
 static ssize_t iommu_group_store_type(struct iommu_group *group,
 				      const char *buf, size_t count)
 {
-	struct group_device *grp_dev;
 	struct device *dev;
 	int ret, req_type;
 
@@ -3000,8 +3002,7 @@ static ssize_t iommu_group_store_type(struct iommu_group *group,
 	}
 
 	/* Since group has only one device */
-	grp_dev = list_first_entry(&group->devices, struct group_device, list);
-	dev = grp_dev->dev;
+	dev = iommu_group_first_dev(group);
 	get_device(dev);
 
 	/*
@@ -3126,21 +3127,18 @@ void iommu_device_unuse_default_domain(struct device *dev)
 
 static int __iommu_group_alloc_blocking_domain(struct iommu_group *group)
 {
-	struct group_device *dev =
-		list_first_entry(&group->devices, struct group_device, list);
+	struct device *dev = iommu_group_first_dev(group);
 
 	if (group->blocking_domain)
 		return 0;
 
-	group->blocking_domain =
-		__iommu_domain_alloc(dev->dev->bus, IOMMU_DOMAIN_BLOCKED);
+	group->blocking_domain = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_BLOCKED);
 	if (!group->blocking_domain) {
 		/*
 		 * For drivers that do not yet understand IOMMU_DOMAIN_BLOCKED
 		 * create an empty domain instead.
 		 */
-		group->blocking_domain = __iommu_domain_alloc(
-			dev->dev->bus, IOMMU_DOMAIN_UNMANAGED);
+		group->blocking_domain = __iommu_domain_alloc(dev->bus, IOMMU_DOMAIN_UNMANAGED);
 		if (!group->blocking_domain)
 			return -EINVAL;
 	}
-- 
2.36.1.dirty