cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure

Currently we have the cpuidle_device field in the acpi_processor_power structure.
This adds a dependency between processor.h and cpuidle.h

Although it is not a real problem, removing this dependency has the benefit of
separating a bit more the cpuidle code from the rest of the acpi code.
Also, the compilation should be a bit improved because we do no longer
include cpuidle.h in processor.h. The preprocessor was generating 30418 loc
and with this patch it generates 30256 loc for processor_thermal.c, a file
which is not concerned at all by cpuidle, like processor_perflib.c and
processor_throttling.c.

That may sound ridiculous, but "small streams make big rivers" :P

This patch moves this field into a static global per cpu variable like what is
done in the intel_idle driver.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

drivers/acpi/processor_idle.c

@@ -79,6 +79,8 @@ module_param(bm_check_disable, uint, 0000);
 static unsigned int latency_factor __read_mostly = 2;
 module_param(latency_factor, uint, 0644);
 
+static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
+
 static int disabled_by_idle_boot_param(void)
 {
 	return boot_option_idle_override == IDLE_POLL ||
@@ -998,7 +1000,7 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr)
 	int i, count = CPUIDLE_DRIVER_STATE_START;
 	struct acpi_processor_cx *cx;
 	struct cpuidle_state_usage *state_usage;
-	struct cpuidle_device *dev = &pr->power.dev;
+	struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
 
 	if (!pr->flags.power_setup_done)
 		return -EINVAL;
@@ -1130,6 +1132,7 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
 int acpi_processor_hotplug(struct acpi_processor *pr)
 {
 	int ret = 0;
+	struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
 
 	if (disabled_by_idle_boot_param())
 		return 0;
@@ -1145,11 +1148,11 @@ int acpi_processor_hotplug(struct acpi_processor *pr)
 		return -ENODEV;
 
 	cpuidle_pause_and_lock();
-	cpuidle_disable_device(&pr->power.dev);
+	cpuidle_disable_device(dev);
 	acpi_processor_get_power_info(pr);
 	if (pr->flags.power) {
 		acpi_processor_setup_cpuidle_cx(pr);
-		ret = cpuidle_enable_device(&pr->power.dev);
+		ret = cpuidle_enable_device(dev);
 	}
 	cpuidle_resume_and_unlock();
 
@@ -1160,6 +1163,7 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr)
 {
 	int cpu;
 	struct acpi_processor *_pr;
+	struct cpuidle_device *dev;
 
 	if (disabled_by_idle_boot_param())
 		return 0;
@@ -1190,7 +1194,8 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr)
 			_pr = per_cpu(processors, cpu);
 			if (!_pr || !_pr->flags.power_setup_done)
 				continue;
-			cpuidle_disable_device(&_pr->power.dev);
+			dev = per_cpu(acpi_cpuidle_device, cpu);
+			cpuidle_disable_device(dev);
 		}
 
 		/* Populate Updated C-state information */
@@ -1204,7 +1209,8 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr)
 			acpi_processor_get_power_info(_pr);
 			if (_pr->flags.power) {
 				acpi_processor_setup_cpuidle_cx(_pr);
-				cpuidle_enable_device(&_pr->power.dev);
+				dev = per_cpu(acpi_cpuidle_device, cpu);
+				cpuidle_enable_device(dev);
 			}
 		}
 		put_online_cpus();
@@ -1220,6 +1226,7 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr)
 {
 	acpi_status status = 0;
 	int retval;
+	struct cpuidle_device *dev;
 	static int first_run;
 
 	if (disabled_by_idle_boot_param())
@@ -1265,11 +1272,18 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr)
 			printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n",
 					acpi_idle_driver.name);
 		}
+
+		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+		if (!dev)
+			return -ENOMEM;
+		per_cpu(acpi_cpuidle_device, pr->id) = dev;
+
+		acpi_processor_setup_cpuidle_cx(pr);
+
 		/* Register per-cpu cpuidle_device. Cpuidle driver
 		 * must already be registered before registering device
 		 */
-		acpi_processor_setup_cpuidle_cx(pr);
-		retval = cpuidle_register_device(&pr->power.dev);
+		retval = cpuidle_register_device(dev);
 		if (retval) {
 			if (acpi_processor_registered == 0)
 				cpuidle_unregister_driver(&acpi_idle_driver);
@@ -1282,11 +1296,13 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr)
 
 int 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;
 
 	if (pr->flags.power) {
-		cpuidle_unregister_device(&pr->power.dev);
+		cpuidle_unregister_device(dev);
 		acpi_processor_registered--;
 		if (acpi_processor_registered == 0)
 			cpuidle_unregister_driver(&acpi_idle_driver);

include/acpi/processor.h

@@ -3,7 +3,6 @@
 
 #include <linux/kernel.h>
 #include <linux/cpu.h>
-#include <linux/cpuidle.h>
 #include <linux/thermal.h>
 #include <asm/acpi.h>
 
@@ -64,7 +63,6 @@ struct acpi_processor_cx {
 };
 
 struct acpi_processor_power {
-	struct cpuidle_device dev;
 	struct acpi_processor_cx *state;
 	unsigned long bm_check_timestamp;
 	u32 default_state;