[Patch V2 1/2] iommu: remove the iommu_callback_data

[Wei Yang <richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

According to the code path, iommu_callback_data is passed in
iommu_bus_init() and  just used in {add/remove}_iommu_group, by when the
bus->iommu_ops is already set up properly.

This patch removes the iommu_callback_data by retrieving iommu_ops from
bus->iommu_ops directly.

Signed-off-by: Wei Yang <richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/iommu/iommu.c |   21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 0e3b009..2696a38 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -37,10 +37,6 @@ static struct kset *iommu_group_kset;
 static struct ida iommu_group_ida;
 static struct mutex iommu_group_mutex;
 
-struct iommu_callback_data {
-	const struct iommu_ops *ops;
-};
-
 struct iommu_group {
 	struct kobject kobj;
 	struct kobject *devices_kobj;
@@ -867,8 +863,7 @@ struct iommu_domain *iommu_group_default_domain(struct iommu_group *group)
 
 static int add_iommu_group(struct device *dev, void *data)
 {
-	struct iommu_callback_data *cb = data;
-	const struct iommu_ops *ops = cb->ops;
+	const struct iommu_ops *ops = dev->bus->iommu_ops;
 	int ret;
 
 	if (!ops->add_device)
@@ -891,8 +886,7 @@ static int add_iommu_group(struct device *dev, void *data)
 
 static int remove_iommu_group(struct device *dev, void *data)
 {
-	struct iommu_callback_data *cb = data;
-	const struct iommu_ops *ops = cb->ops;
+	const struct iommu_ops *ops = dev->bus->iommu_ops;
 
 	if (ops->remove_device && dev->iommu_group)
 		ops->remove_device(dev);
@@ -953,13 +947,10 @@ static int iommu_bus_notifier(struct notifier_block *nb,
 	return 0;
 }
 
-static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops)
+static int iommu_bus_init(struct bus_type *bus)
 {
 	int err;
 	struct notifier_block *nb;
-	struct iommu_callback_data cb = {
-		.ops = ops,
-	};
 
 	nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
 	if (!nb)
@@ -971,7 +962,7 @@ static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops)
 	if (err)
 		goto out_free;
 
-	err = bus_for_each_dev(bus, NULL, &cb, add_iommu_group);
+	err = bus_for_each_dev(bus, NULL, NULL, add_iommu_group);
 	if (err)
 		goto out_err;
 
@@ -980,7 +971,7 @@ static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops)
 
 out_err:
 	/* Clean up */
-	bus_for_each_dev(bus, NULL, &cb, remove_iommu_group);
+	bus_for_each_dev(bus, NULL, NULL, remove_iommu_group);
 	bus_unregister_notifier(bus, nb);
 
 out_free:
@@ -1012,7 +1003,7 @@ int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops)
 	bus->iommu_ops = ops;
 
 	/* Do IOMMU specific setup for this bus-type */
-	err = iommu_bus_init(bus, ops);
+	err = iommu_bus_init(bus);
 	if (err)
 		bus->iommu_ops = NULL;
 
-- 
1.7.9.5