1 files changed, 367 insertions, 0 deletions
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
new file mode 100644
index 000000000..62114a03a
--- /dev/null
+++ b/drivers/acpi/processor_driver.c
@@ -0,0 +1,367 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * processor_driver.c - ACPI Processor Driver
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
+ *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ *  			- Added processor hotplug support
+ *  Copyright (C) 2013, Intel Corporation
+ *                      Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ */
+
+#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
+
+#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
+ACPI_MODULE_NAME("processor_driver");
+
+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_DEBUG_PRINT((ACPI_DB_INFO,
+				  "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");