iommu: Split iommu_group_remove_device() into helpers

So that code could be re-used by iommu_release_device() in the subsequent
change. No intention for functionality change.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230322064956.263419-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index ace9d41..942bab8 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -453,6 +453,46 @@ err_out:
 
 }
 
+/*
+ * Remove a device from a group's device list and return the group device
+ * if successful.
+ */
+static struct group_device *
+__iommu_group_remove_device(struct iommu_group *group, struct device *dev)
+{
+       struct group_device *device;
+
+       lockdep_assert_held(&group->mutex);
+       list_for_each_entry(device, &group->devices, list) {
+               if (device->dev == dev) {
+                       list_del(&device->list);
+                       return device;
+               }
+       }
+
+       return NULL;
+}
+
+/*
+ * Release a device from its group and decrements the iommu group reference
+ * count.
+ */
+static void __iommu_group_release_device(struct iommu_group *group,
+                                        struct group_device *grp_dev)
+{
+       struct device *dev = grp_dev->dev;
+
+       sysfs_remove_link(group->devices_kobj, grp_dev->name);
+       sysfs_remove_link(&dev->kobj, "iommu_group");
+
+       trace_remove_device_from_group(group->id, dev);
+
+       kfree(grp_dev->name);
+       kfree(grp_dev);
+       dev->iommu_group = NULL;
+       kobject_put(group->devices_kobj);
+}
+
 void iommu_release_device(struct device *dev)
 {
        const struct iommu_ops *ops;
@@ -1068,7 +1108,7 @@ EXPORT_SYMBOL_GPL(iommu_group_add_device);
 void iommu_group_remove_device(struct device *dev)
 {
        struct iommu_group *group = dev->iommu_group;
-       struct group_device *tmp_device, *device = NULL;
+       struct group_device *device;
 
        if (!group)
                return;
@@ -1076,27 +1116,11 @@ void iommu_group_remove_device(struct device *dev)
        dev_info(dev, "Removing from iommu group %d\n", group->id);
 
        mutex_lock(&group->mutex);
-       list_for_each_entry(tmp_device, &group->devices, list) {
-               if (tmp_device->dev == dev) {
-                       device = tmp_device;
-                       list_del(&device->list);
-                       break;
-               }
-       }
+       device = __iommu_group_remove_device(group, dev);
        mutex_unlock(&group->mutex);
 
-       if (!device)
-               return;
-
-       sysfs_remove_link(group->devices_kobj, device->name);
-       sysfs_remove_link(&dev->kobj, "iommu_group");
-
-       trace_remove_device_from_group(group->id, dev);
-
-       kfree(device->name);
-       kfree(device);
-       dev->iommu_group = NULL;
-       kobject_put(group->devices_kobj);
+       if (device)
+               __iommu_group_release_device(group, device);
 }
 EXPORT_SYMBOL_GPL(iommu_group_remove_device);