firmware: arm_scmi: improve exit paths and code readability

The existing code intends the good path to reduce the code which is so
uncommon. It's obvious to have more readable code with a goto used for
the error path. This patch adds more appropriate error paths and makes
code more readable. It also moves a error logging outside the scope of
locking.

Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index f2760a596c2872a5baf10d629e53e6d207d2039c..472c88ae1c0f9d37ffae6d094a8500ca85ed3146 100644 (file)
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -125,13 +125,13 @@ scmi_device_create(struct device_node *np, struct device *parent, int protocol)
        int id, retval;
        struct scmi_device *scmi_dev;
 
-       id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL);
-       if (id < 0)
-               return NULL;
-
        scmi_dev = kzalloc(sizeof(*scmi_dev), GFP_KERNEL);
        if (!scmi_dev)
-               goto no_mem;
+               return NULL;
+
+       id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL);
+       if (id < 0)
+               goto free_mem;
 
        scmi_dev->id = id;
        scmi_dev->protocol_id = protocol;
@@ -141,13 +141,15 @@ scmi_device_create(struct device_node *np, struct device *parent, int protocol)
        dev_set_name(&scmi_dev->dev, "scmi_dev.%d", id);
 
        retval = device_register(&scmi_dev->dev);
-       if (!retval)
-               return scmi_dev;
+       if (retval)
+               goto put_dev;
 
+       return scmi_dev;
+put_dev:
        put_device(&scmi_dev->dev);
-       kfree(scmi_dev);
-no_mem:
        ida_simple_remove(&scmi_bus_id, id);
+free_mem:
+       kfree(scmi_dev);
        return NULL;
 }
 
@@ -171,9 +173,9 @@ int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn)
        spin_lock(&protocol_lock);
        ret = idr_alloc(&scmi_protocols, fn, protocol_id, protocol_id + 1,
                        GFP_ATOMIC);
+       spin_unlock(&protocol_lock);
        if (ret != protocol_id)
                pr_err("unable to allocate SCMI idr slot, err %d\n", ret);
-       spin_unlock(&protocol_lock);
 
        return ret;
 }