diff options
Diffstat (limited to 'drivers/acpi/processor_driver.c')
| -rw-r--r-- | drivers/acpi/processor_driver.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c new file mode 100644 index 0000000000..4bd16b3f07 --- /dev/null +++ b/drivers/acpi/processor_driver.c @@ -0,0 +1,311 @@ +// 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 + +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) + return 0; + + device = acpi_fetch_acpi_dev(pr->handle); + if (!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); + + if (!pr || !acpi_fetch_acpi_dev(pr->handle)) + return 0; + + acpi_processor_reevaluate_tstate(pr, true); + return 0; +} + +#ifdef CONFIG_ACPI_CPU_FREQ_PSS +static void acpi_pss_perf_init(struct acpi_processor *pr) +{ + acpi_processor_ppc_has_changed(pr, 0); + + acpi_processor_get_throttling_info(pr); + + if (pr->flags.throttling) + pr->flags.limit = 1; +} +#else +static inline void acpi_pss_perf_init(struct acpi_processor *pr) {} +#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); + + acpi_pss_perf_init(pr); + + result = acpi_processor_thermal_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_processor_thermal_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_cppc_processor_exit(pr); + + acpi_processor_thermal_exit(pr, device); + + 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; + + if (!cpufreq_register_notifier(&acpi_processor_notifier_block, + CPUFREQ_POLICY_NOTIFIER)) { + acpi_processor_cpufreq_init = true; + acpi_processor_ignore_ppc_init(); + } + + 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); + + 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"); |