1 files changed, 82 insertions, 57 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 2c2dc559e0f8..22b051b94a86 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -51,7 +51,7 @@ module_param(latency_factor, uint, 0644);
 
 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
 
-struct cpuidle_driver acpi_idle_driver = {
+static struct cpuidle_driver acpi_idle_driver = {
 	.name =		"acpi_idle",
 	.owner =	THIS_MODULE,
 };
@@ -998,11 +998,6 @@ end:
 	return ret;
 }
 
-/*
- * flat_state_cnt - the number of composite LPI states after the process of flattening
- */
-static int flat_state_cnt;
-
 /**
  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
  *
@@ -1045,9 +1040,10 @@ static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
 	curr_level->composite_states[curr_level->composite_states_size++] = t;
 }
 
-static int flatten_lpi_states(struct acpi_processor *pr,
-			      struct acpi_lpi_states_array *curr_level,
-			      struct acpi_lpi_states_array *prev_level)
+static unsigned int flatten_lpi_states(struct acpi_processor *pr,
+				       unsigned int flat_state_cnt,
+				       struct acpi_lpi_states_array *curr_level,
+				       struct acpi_lpi_states_array *prev_level)
 {
 	int i, j, state_count = curr_level->size;
 	struct acpi_lpi_state *p, *t = curr_level->entries;
@@ -1087,7 +1083,7 @@ static int flatten_lpi_states(struct acpi_processor *pr,
 	}
 
 	kfree(curr_level->entries);
-	return 0;
+	return flat_state_cnt;
 }
 
 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
@@ -1102,6 +1098,7 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
 	acpi_handle handle = pr->handle, pr_ahandle;
 	struct acpi_device *d = NULL;
 	struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
+	unsigned int state_count;
 
 	/* make sure our architecture has support */
 	ret = acpi_processor_ffh_lpi_probe(pr->id);
@@ -1114,14 +1111,13 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
 	if (!acpi_has_method(handle, "_LPI"))
 		return -EINVAL;
 
-	flat_state_cnt = 0;
 	prev = &info[0];
 	curr = &info[1];
 	handle = pr->handle;
 	ret = acpi_processor_evaluate_lpi(handle, prev);
 	if (ret)
 		return ret;
-	flatten_lpi_states(pr, prev, NULL);
+	state_count = flatten_lpi_states(pr, 0, prev, NULL);
 
 	status = acpi_get_parent(handle, &pr_ahandle);
 	while (ACPI_SUCCESS(status)) {
@@ -1143,18 +1139,19 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
 			break;
 
 		/* flatten all the LPI states in this level of hierarchy */
-		flatten_lpi_states(pr, curr, prev);
+		state_count = flatten_lpi_states(pr, state_count, curr, prev);
 
 		tmp = prev, prev = curr, curr = tmp;
 
 		status = acpi_get_parent(handle, &pr_ahandle);
 	}
 
-	pr->power.count = flat_state_cnt;
 	/* reset the index after flattening */
-	for (i = 0; i < pr->power.count; i++)
+	for (i = 0; i < state_count; i++)
 		pr->power.lpi_states[i].index = i;
 
+	pr->power.count = state_count;
+
 	/* Tell driver that _LPI is supported. */
 	pr->flags.has_lpi = 1;
 	pr->flags.power = 1;
@@ -1360,74 +1357,102 @@ int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
 	return 0;
 }
 
-static int acpi_processor_registered;
+void acpi_processor_register_idle_driver(void)
+{
+	struct acpi_processor *pr;
+	int ret = -ENODEV;
+	int cpu;
+
+	/*
+	 * Acpi idle driver is used by all possible CPUs.
+	 * Install the idle handler by the processor power info of one in them.
+	 * Note that we use previously set idle handler will be used on
+	 * platforms that only support C1.
+	 */
+	for_each_cpu(cpu, (struct cpumask *)cpu_possible_mask) {
+		pr = per_cpu(processors, cpu);
+		if (!pr)
+			continue;
+
+		ret = acpi_processor_get_power_info(pr);
+		if (!ret) {
+			pr->flags.power_setup_done = 1;
+			acpi_processor_setup_cpuidle_states(pr);
+			break;
+		}
+	}
+
+	if (ret) {
+		pr_debug("No ACPI power information from any CPUs.\n");
+		return;
+	}
+
+	ret = cpuidle_register_driver(&acpi_idle_driver);
+	if (ret) {
+		pr_debug("register %s failed.\n", acpi_idle_driver.name);
+		return;
+	}
+	pr_debug("%s registered with cpuidle.\n", acpi_idle_driver.name);
+}
+
+void acpi_processor_unregister_idle_driver(void)
+{
+	cpuidle_unregister_driver(&acpi_idle_driver);
+}
 
-int acpi_processor_power_init(struct acpi_processor *pr)
+void acpi_processor_power_init(struct acpi_processor *pr)
 {
-	int retval;
 	struct cpuidle_device *dev;
 
+	/*
+	 * The code below only works if the current cpuidle driver is the ACPI
+	 * idle driver.
+	 */
+	if (cpuidle_get_driver() != &acpi_idle_driver)
+		return;
+
 	if (disabled_by_idle_boot_param())
-		return 0;
+		return;
 
 	acpi_processor_cstate_first_run_checks();
 
 	if (!acpi_processor_get_power_info(pr))
 		pr->flags.power_setup_done = 1;
 
-	/*
-	 * Install the idle handler if processor power management is supported.
-	 * Note that we use previously set idle handler will be used on
-	 * platforms that only support C1.
-	 */
-	if (pr->flags.power) {
-		/* Register acpi_idle_driver if not already registered */
-		if (!acpi_processor_registered) {
-			acpi_processor_setup_cpuidle_states(pr);
-			retval = cpuidle_register_driver(&acpi_idle_driver);
-			if (retval)
-				return retval;
-			pr_debug("%s registered with cpuidle\n",
-				 acpi_idle_driver.name);
-		}
+	if (!pr->flags.power)
+		return;
 
-		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-		if (!dev)
-			return -ENOMEM;
-		per_cpu(acpi_cpuidle_device, pr->id) = dev;
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return;
 
-		acpi_processor_setup_cpuidle_dev(pr, dev);
+	per_cpu(acpi_cpuidle_device, pr->id) = dev;
 
-		/* Register per-cpu cpuidle_device. Cpuidle driver
-		 * must already be registered before registering device
-		 */
-		retval = cpuidle_register_device(dev);
-		if (retval) {
-			if (acpi_processor_registered == 0)
-				cpuidle_unregister_driver(&acpi_idle_driver);
-			return retval;
-		}
-		acpi_processor_registered++;
+	acpi_processor_setup_cpuidle_dev(pr, dev);
+
+	/*
+	 * Register a cpuidle device for this CPU.  The cpuidle driver using
+	 * this device is expected to be registered.
+	 */
+	if (cpuidle_register_device(dev)) {
+		per_cpu(acpi_cpuidle_device, pr->id) = NULL;
+		kfree(dev);
 	}
-	return 0;
 }
 
-int acpi_processor_power_exit(struct acpi_processor *pr)
+void acpi_processor_power_exit(struct acpi_processor *pr)
 {
 	struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
 
 	if (disabled_by_idle_boot_param())
-		return 0;
+		return;
 
 	if (pr->flags.power) {
 		cpuidle_unregister_device(dev);
-		acpi_processor_registered--;
-		if (acpi_processor_registered == 0)
-			cpuidle_unregister_driver(&acpi_idle_driver);
-
 		kfree(dev);
 	}
 
 	pr->flags.power_setup_done = 0;
-	return 0;
 }
+
+MODULE_IMPORT_NS("ACPI_PROCESSOR_IDLE");