intel_idle: Split up and provide per CPU initialization func

Function split up, should have no functional change.

Provides entry point for physically hotplugged CPUs
to initialize and activate cpuidle.
Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
CC: Shaohua Li <shaohua.li@intel.com>
CC: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/idle/intel_idle.c

@@ -478,20 +478,16 @@ static int intel_idle_cpuidle_driver_init(void)
 
 
 /*
- * intel_idle_cpuidle_devices_init()
+ * intel_idle_cpu_init()
  * allocate, initialize, register cpuidle_devices
+ * @cpu: cpu/core to initialize
  */
-static int intel_idle_cpuidle_devices_init(void)
+int intel_idle_cpu_init(int cpu)
 {
-	int i, cstate;
+	int cstate;
 	struct cpuidle_device *dev;
 
-	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
-	if (intel_idle_cpuidle_devices == NULL)
-		return -ENOMEM;
-
-	for_each_online_cpu(i) {
-		dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
+	dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
 
 	dev->state_count = 1;
 
@@ -510,24 +506,24 @@ static int intel_idle_cpuidle_devices_init(void)
 		if (num_substates == 0)
 			continue;
 		/* is the state not enabled? */
-			if (cpuidle_state_table[cstate].enter == NULL) {
+		if (cpuidle_state_table[cstate].enter == NULL)
 			continue;
-			}
 
 		dev->states_usage[dev->state_count].driver_data =
 			(void *)get_driver_data(cstate);
 
 			dev->state_count += 1;
 		}
+	dev->cpu = cpu;
 
-		dev->cpu = i;
 	if (cpuidle_register_device(dev)) {
-			pr_debug(PREFIX "cpuidle_register_device %d failed!\n",
-				 i);
+		pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
 		intel_idle_cpuidle_devices_uninit();
 		return -EIO;
 	}
-	}
+
+	if (auto_demotion_disable_flags)
+		smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
 
 	return 0;
 }
@@ -535,7 +531,7 @@ static int intel_idle_cpuidle_devices_init(void)
 
 static int __init intel_idle_init(void)
 {
-	int retval;
+	int retval, i;
 
 	/* Do not load intel_idle at all for now if idle= is passed */
 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
@@ -553,11 +549,17 @@ static int __init intel_idle_init(void)
 		return retval;
 	}
 
-	retval = intel_idle_cpuidle_devices_init();
+	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
+	if (intel_idle_cpuidle_devices == NULL)
+		return -ENOMEM;
+
+	for_each_online_cpu(i) {
+		retval = intel_idle_cpu_init(i);
 		if (retval) {
 			cpuidle_unregister_driver(&intel_idle_driver);
 			return retval;
 		}
+	}
 
 	return 0;
 }

include/linux/cpuidle.h

@@ -188,7 +188,14 @@ struct cpuidle_governor {
 extern int cpuidle_register_governor(struct cpuidle_governor *gov);
 extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
 
+#ifdef CONFIG_INTEL_IDLE
+extern int intel_idle_cpu_init(int cpu);
 #else
+static inline int intel_idle_cpu_init(int cpu) { return -1; }
+#endif
+
+#else
+static inline int intel_idle_cpu_init(int cpu) { return -1; }
 
 static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 {return 0;}