[RFC PATCH 5/5] ACPI: thermal: processor: Use the generic cpufreq infrastructure

[Amit Daniel Kachhap <amit.daniel@samsung.com>]

This patch upgrades the ACPI cpufreq cooling portions to use the generic
cpufreq cooling infrastructure. There should not be any functionality
related changes as the same behaviour is provided by the generic
cpufreq APIs with the notifier mechanism.

Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
---
 drivers/acpi/processor_driver.c  |    6 +-
 drivers/acpi/processor_thermal.c |  210 +++++++++++++++++---------------------
 2 files changed, 99 insertions(+), 117 deletions(-)

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 7f70f31..10aba4a 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -36,6 +36,7 @@
 #include <linux/cpuidle.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
+#include <linux/cpu_cooling.h>
 
 #include <acpi/processor.h>
 
@@ -178,8 +179,7 @@ static int __acpi_processor_start(struct acpi_device *device)
 	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 		acpi_processor_power_init(pr);
 
-	pr->cdev = thermal_cooling_device_register("Processor", device,
-						   &processor_cooling_ops);
+	pr->cdev = acpi_processor_cooling_register(device);
 	if (IS_ERR(pr->cdev)) {
 		result = PTR_ERR(pr->cdev);
 		goto err_power_exit;
@@ -250,7 +250,7 @@ static int acpi_processor_stop(struct device *dev)
 	if (pr->cdev) {
 		sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 		sysfs_remove_link(&pr->cdev->device.kobj, "device");
-		thermal_cooling_device_unregister(pr->cdev);
+		cpufreq_cooling_unregister(pr->cdev);
 		pr->cdev = NULL;
 	}
 	return 0;
diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index e003663..c442a58 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -31,6 +31,7 @@
 #include <linux/init.h>
 #include <linux/cpufreq.h>
 #include <linux/acpi.h>
+#include <linux/cpu_cooling.h>
 #include <acpi/processor.h>
 #include <asm/uaccess.h>
 
@@ -53,28 +54,11 @@ ACPI_MODULE_NAME("processor_thermal");
 
 static DEFINE_PER_CPU(unsigned int, cpufreq_thermal_reduction_pctg);
 static unsigned int acpi_thermal_cpufreq_is_init = 0;
+static struct notifier_block cpufreq_cooling_notifier_block;
 
 #define reduction_pctg(cpu) \
 	per_cpu(cpufreq_thermal_reduction_pctg, phys_package_first_cpu(cpu))
 
-/*
- * Emulate "per package data" using per cpu data (which should really be
- * provided elsewhere)
- *
- * Note we can lose a CPU on cpu hotunplug, in this case we forget the state
- * temporarily. Fortunately that's not a big issue here (I hope)
- */
-static int phys_package_first_cpu(int cpu)
-{
-	int i;
-	int id = topology_physical_package_id(cpu);
-
-	for_each_online_cpu(i)
-		if (topology_physical_package_id(i) == id)
-			return i;
-	return 0;
-}
-
 static int cpu_has_cpufreq(unsigned int cpu)
 {
 	struct cpufreq_policy policy;
@@ -83,30 +67,6 @@ static int cpu_has_cpufreq(unsigned int cpu)
 	return 1;
 }
 
-static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
-					 unsigned long event, void *data)
-{
-	struct cpufreq_policy *policy = data;
-	unsigned long max_freq = 0;
-
-	if (event != CPUFREQ_ADJUST)
-		goto out;
-
-	max_freq = (
-	    policy->cpuinfo.max_freq *
-	    (100 - reduction_pctg(policy->cpu) * 20)
-	) / 100;
-
-	cpufreq_verify_within_limits(policy, 0, max_freq);
-
-      out:
-	return 0;
-}
-
-static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
-	.notifier_call = acpi_thermal_cpufreq_notifier,
-};
-
 static int cpufreq_get_max_state(unsigned int cpu)
 {
 	if (!cpu_has_cpufreq(cpu))
@@ -123,34 +83,32 @@ static int cpufreq_get_cur_state(unsigned int cpu)
 	return reduction_pctg(cpu);
 }
 
-static int cpufreq_set_cur_state(unsigned int cpu, int state)
+static int acpi_processor_freq_level(unsigned int cpu, int state)
 {
-	int i;
+	struct cpufreq_policy policy;
+	unsigned long max_freq = 0;
+	int level = 0;
 
-	if (!cpu_has_cpufreq(cpu))
+	if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
 		return 0;
 
 	reduction_pctg(cpu) = state;
+	max_freq = (
+	    policy.cpuinfo.max_freq *
+	    (100 - reduction_pctg(cpu) * 20)
+	) / 100;
 
-	/*
-	 * Update all the CPUs in the same package because they all
-	 * contribute to the temperature and often share the same
-	 * frequency.
-	 */
-	for_each_online_cpu(i) {
-		if (topology_physical_package_id(i) ==
-		    topology_physical_package_id(cpu))
-			cpufreq_update_policy(i);
-	}
-	return 0;
+	level =  cpufreq_cooling_get_level(phys_package_first_cpu(cpu),
+						max_freq, GET_LEVEL_FLOOR);
+	return level;
 }
 
 void acpi_thermal_cpufreq_init(void)
 {
 	int i;
 
-	i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
-				      CPUFREQ_POLICY_NOTIFIER);
+	i = cpufreq_cooling_register_notifier(&cpufreq_cooling_notifier_block,
+					CPU_COOLING_STATE_NOTIFIER);
 	if (!i)
 		acpi_thermal_cpufreq_is_init = 1;
 }
@@ -158,9 +116,9 @@ void acpi_thermal_cpufreq_init(void)
 void acpi_thermal_cpufreq_exit(void)
 {
 	if (acpi_thermal_cpufreq_is_init)
-		cpufreq_unregister_notifier
-		    (&acpi_thermal_cpufreq_notifier_block,
-		     CPUFREQ_POLICY_NOTIFIER);
+		cpufreq_cooling_unregister_notifier(
+						&cpufreq_cooling_notifier_block,
+						CPU_COOLING_STATE_NOTIFIER);
 
 	acpi_thermal_cpufreq_is_init = 0;
 }
@@ -176,13 +134,31 @@ static int cpufreq_get_cur_state(unsigned int cpu)
 	return 0;
 }
 
-static int cpufreq_set_cur_state(unsigned int cpu, int state)
+static int acpi_processor_freq_level(unsigned int cpu, int state)
 {
 	return 0;
 }
 
 #endif
 
+/*
+ * Emulate "per package data" using per cpu data (which should really be
+ * provided elsewhere)
+ *
+ * Note we can lose a CPU on cpu hotunplug, in this case we forget the state
+ * temporarily. Fortunately that's not a big issue here (I hope)
+ */
+static int phys_package_first_cpu(int cpu)
+{
+	int i;
+	int id = topology_physical_package_id(cpu);
+
+	for_each_online_cpu(i)
+		if (topology_physical_package_id(i) == id)
+			return i;
+	return 0;
+}
+
 /* thermal cooling device callbacks */
 static int acpi_processor_max_state(struct acpi_processor *pr)
 {
@@ -198,57 +174,22 @@ static int acpi_processor_max_state(struct acpi_processor *pr)
 
 	return max_state;
 }
-static int
-processor_get_max_state(struct thermal_cooling_device *cdev,
-			unsigned long *state)
-{
-	struct acpi_device *device = cdev->devdata;
-	struct acpi_processor *pr;
-
-	if (!device)
-		return -EINVAL;
-
-	pr = acpi_driver_data(device);
-	if (!pr)
-		return -EINVAL;
 
-	*state = acpi_processor_max_state(pr);
-	return 0;
-}
-
-static int
-processor_get_cur_state(struct thermal_cooling_device *cdev,
-			unsigned long *cur_state)
+static int acpi_processor_cur_state(struct acpi_processor *pr)
 {
-	struct acpi_device *device = cdev->devdata;
-	struct acpi_processor *pr;
-
-	if (!device)
-		return -EINVAL;
-
-	pr = acpi_driver_data(device);
-	if (!pr)
-		return -EINVAL;
-
-	*cur_state = cpufreq_get_cur_state(pr->id);
+	int cur_state = 0;
+	cur_state = cpufreq_get_cur_state(pr->id);
 	if (pr->flags.throttling)
-		*cur_state += pr->throttling.state;
-	return 0;
+		cur_state += pr->throttling.state;
+	return cur_state;
 }
 
-static int
-processor_set_cur_state(struct thermal_cooling_device *cdev,
-			unsigned long state)
+static int acpi_processor_set_cur_state(struct acpi_processor *pr,
+		struct cpufreq_cooling_status *cooling,	unsigned long event)
 {
-	struct acpi_device *device = cdev->devdata;
-	struct acpi_processor *pr;
-	int result = 0;
-	int max_pstate;
-
-	if (!device)
-		return -EINVAL;
+	int result = 0, level = 0;
+	int max_pstate, state = cooling->new_state;
 
-	pr = acpi_driver_data(device);
 	if (!pr)
 		return -EINVAL;
 
@@ -257,20 +198,61 @@ processor_set_cur_state(struct thermal_cooling_device *cdev,
 	if (state > acpi_processor_max_state(pr))
 		return -EINVAL;
 
-	if (state <= max_pstate) {
+	if (state <= max_pstate && event == CPU_COOLING_SET_STATE_PRE) {
 		if (pr->flags.throttling && pr->throttling.state)
 			result = acpi_processor_set_throttling(pr, 0, false);
-		cpufreq_set_cur_state(pr->id, state);
-	} else {
-		cpufreq_set_cur_state(pr->id, max_pstate);
+	} else if (state > max_pstate && event == CPU_COOLING_SET_STATE_POST) {
 		result = acpi_processor_set_throttling(pr,
 				state - max_pstate, false);
 	}
+
+	level = acpi_processor_freq_level(pr->id, state);
+	cooling->new_state = level;
+
 	return result;
 }
 
-const struct thermal_cooling_device_ops processor_cooling_ops = {
-	.get_max_state = processor_get_max_state,
-	.get_cur_state = processor_get_cur_state,
-	.set_cur_state = processor_set_cur_state,
+static int acpi_cpufreq_cooling_notifier(struct notifier_block *nb,
+					 unsigned long event, void *data)
+{
+	struct cpufreq_cooling_status *cooling = data;
+	struct acpi_device *device = cooling->devdata;
+	struct acpi_processor *pr = acpi_driver_data(device);
+	switch (event) {
+	case CPU_COOLING_SET_STATE_PRE:
+	case CPU_COOLING_SET_STATE_POST:
+		acpi_processor_set_cur_state(pr, cooling, event);
+		break;
+	case CPU_COOLING_GET_MAX_STATE:
+		cooling->max_state = acpi_processor_max_state(pr);
+		break;
+	case CPU_COOLING_GET_CUR_STATE:
+		cooling->cur_state = acpi_processor_cur_state(pr);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static struct notifier_block cpufreq_cooling_notifier_block = {
+	.notifier_call = acpi_cpufreq_cooling_notifier,
 };
+
+struct thermal_cooling_device *
+acpi_processor_cooling_register(struct acpi_device *device)
+{
+	struct thermal_cooling_device *cdev;
+	struct acpi_processor *pr = acpi_driver_data(device);
+	int cpu = phys_package_first_cpu(pr->id);
+	int i;
+	int id = topology_physical_package_id(cpu);
+	struct cpumask cpus;
+
+	for_each_online_cpu(i)
+		if (topology_physical_package_id(i) == id)
+			cpumask_set_cpu(i, &cpus);
+
+	cdev = cpufreq_cooling_register(&cpus, (void *)device);
+	return cdev;
+}
-- 
1.7.1