drivers/acpi/processor_driver.c - kernel/common - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * processor_driver.c - ACPI Processor Driver
  *
  *  Copyright (C) 2001, 2002 Andy Grover <[email protected]>
  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
  *  Copyright (C) 2004       Dominik Brodowski <[email protected]>
  *  Copyright (C) 2004  Anil S Keshavamurthy <[email protected]>
  *  			- Added processor hotplug support
  *  Copyright (C) 2013, Intel Corporation
  *                      Rafael J. Wysocki <[email protected]>
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/cpufreq.h>
 #include <linux/cpu.h>
 #include <linux/cpuidle.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>

 #include <acpi/processor.h>

 #include "internal.h"

 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
 #define ACPI_PROCESSOR_NOTIFY_POWER	0x81
 #define ACPI_PROCESSOR_NOTIFY_THROTTLING	0x82

 MODULE_AUTHOR("Paul Diefenbaugh");
 MODULE_DESCRIPTION("ACPI Processor Driver");
 MODULE_LICENSE("GPL");

 static int acpi_processor_start(struct device *dev);
 static int acpi_processor_stop(struct device *dev);

 static const struct acpi_device_id processor_device_ids[] = {
 	{ACPI_PROCESSOR_OBJECT_HID, 0},
 	{ACPI_PROCESSOR_DEVICE_HID, 0},
 	{"", 0},
 };
 MODULE_DEVICE_TABLE(acpi, processor_device_ids);

 static struct device_driver acpi_processor_driver = {
 	.name = "processor",
 	.bus = &cpu_subsys,
 	.acpi_match_table = processor_device_ids,
 	.probe = acpi_processor_start,
 	.remove = acpi_processor_stop,
 };

 static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
 {
 	struct acpi_device *device = data;
 	struct acpi_processor *pr;
 	int saved;

 	if (device->handle != handle)
 		return;

 	pr = acpi_driver_data(device);
 	if (!pr)
 		return;

 	switch (event) {
 	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
 		saved = pr->performance_platform_limit;
 		acpi_processor_ppc_has_changed(pr, 1);
 		if (saved == pr->performance_platform_limit)
 			break;
 		acpi_bus_generate_netlink_event(device->pnp.device_class,
 						  dev_name(&device->dev), event,
 						  pr->performance_platform_limit);
 		break;
 	case ACPI_PROCESSOR_NOTIFY_POWER:
 		acpi_processor_power_state_has_changed(pr);
 		acpi_bus_generate_netlink_event(device->pnp.device_class,
 						  dev_name(&device->dev), event, 0);
 		break;
 	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
 		acpi_processor_tstate_has_changed(pr);
 		acpi_bus_generate_netlink_event(device->pnp.device_class,
 						  dev_name(&device->dev), event, 0);
 		break;
 	default:
 		acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
 		break;
 	}

 	return;
 }

 static int __acpi_processor_start(struct acpi_device *device);

 static int acpi_soft_cpu_online(unsigned int cpu)
 {
 	struct acpi_processor *pr = per_cpu(processors, cpu);
 	struct acpi_device *device;

 	if (!pr || acpi_bus_get_device(pr->handle, &device))
 		return 0;
 	/*
 	 * CPU got physically hotplugged and onlined for the first time:
 	 * Initialize missing things.
 	 */
 	if (pr->flags.need_hotplug_init) {
 		int ret;

 		pr_info("Will online and init hotplugged CPU: %d\n",
 			pr->id);
 		pr->flags.need_hotplug_init = 0;
 		ret = __acpi_processor_start(device);
 		WARN(ret, "Failed to start CPU: %d\n", pr->id);
 	} else {
 		/* Normal CPU soft online event. */
 		acpi_processor_ppc_has_changed(pr, 0);
 		acpi_processor_hotplug(pr);
 		acpi_processor_reevaluate_tstate(pr, false);
 		acpi_processor_tstate_has_changed(pr);
 	}
 	return 0;
 }

 static int acpi_soft_cpu_dead(unsigned int cpu)
 {
 	struct acpi_processor *pr = per_cpu(processors, cpu);
 	struct acpi_device *device;

 	if (!pr || acpi_bus_get_device(pr->handle, &device))
 		return 0;

 	acpi_processor_reevaluate_tstate(pr, true);
 	return 0;
 }

 #ifdef CONFIG_ACPI_CPU_FREQ_PSS
 static int acpi_pss_perf_init(struct acpi_processor *pr,
 		struct acpi_device *device)
 {
 	int result = 0;

 	acpi_processor_ppc_has_changed(pr, 0);

 	acpi_processor_get_throttling_info(pr);

 	if (pr->flags.throttling)
 		pr->flags.limit = 1;

 	pr->cdev = thermal_cooling_device_register("Processor", device,
 						   &processor_cooling_ops);
 	if (IS_ERR(pr->cdev)) {
 		result = PTR_ERR(pr->cdev);
 		return result;
 	}

 	dev_dbg(&device->dev, "registered as cooling_device%d\n",
 		pr->cdev->id);

 	result = sysfs_create_link(&device->dev.kobj,
 				   &pr->cdev->device.kobj,
 				   "thermal_cooling");
 	if (result) {
 		dev_err(&device->dev,
 			"Failed to create sysfs link 'thermal_cooling'\n");
 		goto err_thermal_unregister;
 	}

 	result = sysfs_create_link(&pr->cdev->device.kobj,
 				   &device->dev.kobj,
 				   "device");
 	if (result) {
 		dev_err(&pr->cdev->device,
 			"Failed to create sysfs link 'device'\n");
 		goto err_remove_sysfs_thermal;
 	}

 	return 0;

  err_remove_sysfs_thermal:
 	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
  err_thermal_unregister:
 	thermal_cooling_device_unregister(pr->cdev);

 	return result;
 }

 static void acpi_pss_perf_exit(struct acpi_processor *pr,
 		struct acpi_device *device)
 {
 	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);
 		pr->cdev = NULL;
 	}
 }
 #else
 static inline int acpi_pss_perf_init(struct acpi_processor *pr,
 		struct acpi_device *device)
 {
 	return 0;
 }

 static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
 		struct acpi_device *device) {}
 #endif /* CONFIG_ACPI_CPU_FREQ_PSS */

 static int __acpi_processor_start(struct acpi_device *device)
 {
 	struct acpi_processor *pr = acpi_driver_data(device);
 	acpi_status status;
 	int result = 0;

 	if (!pr)
 		return -ENODEV;

 	if (pr->flags.need_hotplug_init)
 		return 0;

 	result = acpi_cppc_processor_probe(pr);
 	if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
 		dev_dbg(&device->dev, "CPPC data invalid or not present\n");

 	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 		acpi_processor_power_init(pr);

 	result = acpi_pss_perf_init(pr, device);
 	if (result)
 		goto err_power_exit;

 	status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 					     acpi_processor_notify, device);
 	if (ACPI_SUCCESS(status))
 		return 0;

 	result = -ENODEV;
 	acpi_pss_perf_exit(pr, device);

 err_power_exit:
 	acpi_processor_power_exit(pr);
 	return result;
 }

 static int acpi_processor_start(struct device *dev)
 {
 	struct acpi_device *device = ACPI_COMPANION(dev);
 	int ret;

 	if (!device)
 		return -ENODEV;

 	/* Protect against concurrent CPU hotplug operations */
 	cpu_hotplug_disable();
 	ret = __acpi_processor_start(device);
 	cpu_hotplug_enable();
 	return ret;
 }

 static int acpi_processor_stop(struct device *dev)
 {
 	struct acpi_device *device = ACPI_COMPANION(dev);
 	struct acpi_processor *pr;

 	if (!device)
 		return 0;

 	acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
 				   acpi_processor_notify);

 	pr = acpi_driver_data(device);
 	if (!pr)
 		return 0;
 	acpi_processor_power_exit(pr);

 	acpi_pss_perf_exit(pr, device);

 	acpi_cppc_processor_exit(pr);

 	return 0;
 }

 bool acpi_processor_cpufreq_init;

 static int acpi_processor_notifier(struct notifier_block *nb,
 				   unsigned long event, void *data)
 {
 	struct cpufreq_policy *policy = data;

 	if (event == CPUFREQ_CREATE_POLICY) {
 		acpi_thermal_cpufreq_init(policy);
 		acpi_processor_ppc_init(policy);
 	} else if (event == CPUFREQ_REMOVE_POLICY) {
 		acpi_processor_ppc_exit(policy);
 		acpi_thermal_cpufreq_exit(policy);
 	}

 	return 0;
 }

 static struct notifier_block acpi_processor_notifier_block = {
 	.notifier_call = acpi_processor_notifier,
 };

 /*
  * We keep the driver loaded even when ACPI is not running.
  * This is needed for the powernow-k8 driver, that works even without
  * ACPI, but needs symbols from this driver
  */
 static enum cpuhp_state hp_online;
 static int __init acpi_processor_driver_init(void)
 {
 	int result = 0;

 	if (acpi_disabled)
 		return 0;

 	result = driver_register(&acpi_processor_driver);
 	if (result < 0)
 		return result;

 	result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
 					   "acpi/cpu-drv:online",
 					   acpi_soft_cpu_online, NULL);
 	if (result < 0)
 		goto err;
 	hp_online = result;
 	cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
 				  NULL, acpi_soft_cpu_dead);

 	if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
 				       CPUFREQ_POLICY_NOTIFIER)) {
 		acpi_processor_cpufreq_init = true;
 		acpi_processor_ignore_ppc_init();
 	}

 	acpi_processor_throttling_init();
 	return 0;
 err:
 	driver_unregister(&acpi_processor_driver);
 	return result;
 }

 static void __exit acpi_processor_driver_exit(void)
 {
 	if (acpi_disabled)
 		return;

 	if (acpi_processor_cpufreq_init) {
 		cpufreq_unregister_notifier(&acpi_processor_notifier_block,
 					    CPUFREQ_POLICY_NOTIFIER);
 		acpi_processor_cpufreq_init = false;
 	}

 	cpuhp_remove_state_nocalls(hp_online);
 	cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
 	driver_unregister(&acpi_processor_driver);
 }

 module_init(acpi_processor_driver_init);
 module_exit(acpi_processor_driver_exit);

 MODULE_ALIAS("processor");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* processor_driver.c - ACPI Processor Driver
	*
	* Copyright (C) 2001, 2002 Andy Grover <[email protected]>
	* Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
	* Copyright (C) 2004 Dominik Brodowski <[email protected]>
	* Copyright (C) 2004 Anil S Keshavamurthy <[email protected]>
	* - Added processor hotplug support
	* Copyright (C) 2013, Intel Corporation
	* Rafael J. Wysocki <[email protected]>
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/cpufreq.h>
	#include <linux/cpu.h>
	#include <linux/cpuidle.h>
	#include <linux/slab.h>
	#include <linux/acpi.h>

	#include <acpi/processor.h>

	#include "internal.h"

	#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
	#define ACPI_PROCESSOR_NOTIFY_POWER 0x81
	#define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82

	MODULE_AUTHOR("Paul Diefenbaugh");
	MODULE_DESCRIPTION("ACPI Processor Driver");
	MODULE_LICENSE("GPL");

	static int acpi_processor_start(struct device *dev);
	static int acpi_processor_stop(struct device *dev);

	static const struct acpi_device_id processor_device_ids[] = {
	{ACPI_PROCESSOR_OBJECT_HID, 0},
	{ACPI_PROCESSOR_DEVICE_HID, 0},
	{"", 0},
	};
	MODULE_DEVICE_TABLE(acpi, processor_device_ids);

	static struct device_driver acpi_processor_driver = {
	.name = "processor",
	.bus = &cpu_subsys,
	.acpi_match_table = processor_device_ids,
	.probe = acpi_processor_start,
	.remove = acpi_processor_stop,
	};

	static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
	{
	struct acpi_device *device = data;
	struct acpi_processor *pr;
	int saved;

	if (device->handle != handle)
	return;

	pr = acpi_driver_data(device);
	if (!pr)
	return;

	switch (event) {
	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
	saved = pr->performance_platform_limit;
	acpi_processor_ppc_has_changed(pr, 1);
	if (saved == pr->performance_platform_limit)
	break;
	acpi_bus_generate_netlink_event(device->pnp.device_class,
	dev_name(&device->dev), event,
	pr->performance_platform_limit);
	break;
	case ACPI_PROCESSOR_NOTIFY_POWER:
	acpi_processor_power_state_has_changed(pr);
	acpi_bus_generate_netlink_event(device->pnp.device_class,
	dev_name(&device->dev), event, 0);
	break;
	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
	acpi_processor_tstate_has_changed(pr);
	acpi_bus_generate_netlink_event(device->pnp.device_class,
	dev_name(&device->dev), event, 0);
	break;
	default:
	acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
	break;
	}

	return;
	}

	static int __acpi_processor_start(struct acpi_device *device);

	static int acpi_soft_cpu_online(unsigned int cpu)
	{
	struct acpi_processor *pr = per_cpu(processors, cpu);
	struct acpi_device *device;

	if (!pr \|\| acpi_bus_get_device(pr->handle, &device))
	return 0;
	/*
	* CPU got physically hotplugged and onlined for the first time:
	* Initialize missing things.
	*/
	if (pr->flags.need_hotplug_init) {
	int ret;

	pr_info("Will online and init hotplugged CPU: %d\n",
	pr->id);
	pr->flags.need_hotplug_init = 0;
	ret = __acpi_processor_start(device);
	WARN(ret, "Failed to start CPU: %d\n", pr->id);
	} else {
	/* Normal CPU soft online event. */
	acpi_processor_ppc_has_changed(pr, 0);
	acpi_processor_hotplug(pr);
	acpi_processor_reevaluate_tstate(pr, false);
	acpi_processor_tstate_has_changed(pr);
	}
	return 0;
	}

	static int acpi_soft_cpu_dead(unsigned int cpu)
	{
	struct acpi_processor *pr = per_cpu(processors, cpu);
	struct acpi_device *device;

	if (!pr \|\| acpi_bus_get_device(pr->handle, &device))
	return 0;

	acpi_processor_reevaluate_tstate(pr, true);
	return 0;
	}

	#ifdef CONFIG_ACPI_CPU_FREQ_PSS
	static int acpi_pss_perf_init(struct acpi_processor *pr,
	struct acpi_device *device)
	{
	int result = 0;

	acpi_processor_ppc_has_changed(pr, 0);

	acpi_processor_get_throttling_info(pr);

	if (pr->flags.throttling)
	pr->flags.limit = 1;

	pr->cdev = thermal_cooling_device_register("Processor", device,
	&processor_cooling_ops);
	if (IS_ERR(pr->cdev)) {
	result = PTR_ERR(pr->cdev);
	return result;
	}

	dev_dbg(&device->dev, "registered as cooling_device%d\n",
	pr->cdev->id);

	result = sysfs_create_link(&device->dev.kobj,
	&pr->cdev->device.kobj,
	"thermal_cooling");
	if (result) {
	dev_err(&device->dev,
	"Failed to create sysfs link 'thermal_cooling'\n");
	goto err_thermal_unregister;
	}

	result = sysfs_create_link(&pr->cdev->device.kobj,
	&device->dev.kobj,
	"device");
	if (result) {
	dev_err(&pr->cdev->device,
	"Failed to create sysfs link 'device'\n");
	goto err_remove_sysfs_thermal;
	}

	return 0;

	err_remove_sysfs_thermal:
	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
	err_thermal_unregister:
	thermal_cooling_device_unregister(pr->cdev);

	return result;
	}

	static void acpi_pss_perf_exit(struct acpi_processor *pr,
	struct acpi_device *device)
	{
	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);
	pr->cdev = NULL;
	}
	}
	#else
	static inline int acpi_pss_perf_init(struct acpi_processor *pr,
	struct acpi_device *device)
	{
	return 0;
	}

	static inline void acpi_pss_perf_exit(struct acpi_processor *pr,
	struct acpi_device *device) {}
	#endif /* CONFIG_ACPI_CPU_FREQ_PSS */

	static int __acpi_processor_start(struct acpi_device *device)
	{
	struct acpi_processor *pr = acpi_driver_data(device);
	acpi_status status;
	int result = 0;

	if (!pr)
	return -ENODEV;

	if (pr->flags.need_hotplug_init)
	return 0;

	result = acpi_cppc_processor_probe(pr);
	if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
	dev_dbg(&device->dev, "CPPC data invalid or not present\n");

	if (!cpuidle_get_driver() \|\| cpuidle_get_driver() == &acpi_idle_driver)
	acpi_processor_power_init(pr);

	result = acpi_pss_perf_init(pr, device);
	if (result)
	goto err_power_exit;

	status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
	acpi_processor_notify, device);
	if (ACPI_SUCCESS(status))
	return 0;

	result = -ENODEV;
	acpi_pss_perf_exit(pr, device);

	err_power_exit:
	acpi_processor_power_exit(pr);
	return result;
	}

	static int acpi_processor_start(struct device *dev)
	{
	struct acpi_device *device = ACPI_COMPANION(dev);
	int ret;

	if (!device)
	return -ENODEV;

	/* Protect against concurrent CPU hotplug operations */
	cpu_hotplug_disable();
	ret = __acpi_processor_start(device);
	cpu_hotplug_enable();
	return ret;
	}

	static int acpi_processor_stop(struct device *dev)
	{
	struct acpi_device *device = ACPI_COMPANION(dev);
	struct acpi_processor *pr;

	if (!device)
	return 0;

	acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
	acpi_processor_notify);

	pr = acpi_driver_data(device);
	if (!pr)
	return 0;
	acpi_processor_power_exit(pr);

	acpi_pss_perf_exit(pr, device);

	acpi_cppc_processor_exit(pr);

	return 0;
	}

	bool acpi_processor_cpufreq_init;

	static int acpi_processor_notifier(struct notifier_block *nb,
	unsigned long event, void *data)
	{
	struct cpufreq_policy *policy = data;

	if (event == CPUFREQ_CREATE_POLICY) {
	acpi_thermal_cpufreq_init(policy);
	acpi_processor_ppc_init(policy);
	} else if (event == CPUFREQ_REMOVE_POLICY) {
	acpi_processor_ppc_exit(policy);
	acpi_thermal_cpufreq_exit(policy);
	}

	return 0;
	}

	static struct notifier_block acpi_processor_notifier_block = {
	.notifier_call = acpi_processor_notifier,
	};

	/*
	* We keep the driver loaded even when ACPI is not running.
	* This is needed for the powernow-k8 driver, that works even without
	* ACPI, but needs symbols from this driver
	*/
	static enum cpuhp_state hp_online;
	static int __init acpi_processor_driver_init(void)
	{
	int result = 0;

	if (acpi_disabled)
	return 0;

	result = driver_register(&acpi_processor_driver);
	if (result < 0)
	return result;

	result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
	"acpi/cpu-drv:online",
	acpi_soft_cpu_online, NULL);
	if (result < 0)
	goto err;
	hp_online = result;
	cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
	NULL, acpi_soft_cpu_dead);

	if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
	CPUFREQ_POLICY_NOTIFIER)) {
	acpi_processor_cpufreq_init = true;
	acpi_processor_ignore_ppc_init();
	}

	acpi_processor_throttling_init();
	return 0;
	err:
	driver_unregister(&acpi_processor_driver);
	return result;
	}

	static void __exit acpi_processor_driver_exit(void)
	{
	if (acpi_disabled)
	return;

	if (acpi_processor_cpufreq_init) {
	cpufreq_unregister_notifier(&acpi_processor_notifier_block,
	CPUFREQ_POLICY_NOTIFIER);
	acpi_processor_cpufreq_init = false;
	}

	cpuhp_remove_state_nocalls(hp_online);
	cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
	driver_unregister(&acpi_processor_driver);
	}

	module_init(acpi_processor_driver_init);
	module_exit(acpi_processor_driver_exit);

	MODULE_ALIAS("processor");