cpu/SMT: Move smt/control simple exit cases earlier

Move the simple exit cases, i.e. those which don't depend on the value written, earlier in the function. That makes it clearer that regardless of the input those states cannot be transitioned out of. That does have a user-visible effect, in that the error returned will now always be EPERM/ENODEV for those states, regardless of the value written. Previously writing an invalid value would return EINVAL even when in those states. Signed-off-by: Michael Ellerman <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Tested-by: Zhang Rui <[email protected]> Link: https://lore.kernel.org/r/[email protected]
wafgo · Jul 28, 2023 · c53361c · c53361c
1 parent 3f91691
commit c53361c
Showing 1 changed file with 6 additions and 6 deletions.
diff --git a/kernel/cpu.c b/kernel/cpu.c
@@ -2841,6 +2841,12 @@ __store_smt_control(struct device *dev, struct device_attribute *attr,
 {
 	int ctrlval, ret;
 
+	if (cpu_smt_control == CPU_SMT_FORCE_DISABLED)
+		return -EPERM;
+
+	if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
+		return -ENODEV;
+
 	if (sysfs_streq(buf, "on"))
 		ctrlval = CPU_SMT_ENABLED;
 	else if (sysfs_streq(buf, "off"))
@@ -2850,12 +2856,6 @@ __store_smt_control(struct device *dev, struct device_attribute *attr,
 	else
 		return -EINVAL;
 
-	if (cpu_smt_control == CPU_SMT_FORCE_DISABLED)
-		return -EPERM;
-
-	if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
-		return -ENODEV;
-
 	ret = lock_device_hotplug_sysfs();
 	if (ret)
 		return ret;