The ACPI processor driver is currently tied too closely to the ACPI P-states (PSS) and other related constructs for controlling CPU performance.
The newer ACPI specification (v5.1 onwards) introduces alternative methods to PSS. These new mechanisms are described within each ACPI Processor object and so they need to be scanned whenever a new Processor object is detected. This patch introduces a new Kconfig symbol to allow for finer configurability among the two options for controlling performance states. There is no change in functionality and the option is auto-selected by the architectures which support it.
The following patchwork introduces CPPC: A newer method of controlling CPU performance. The OS is not expected to support CPPC and PSS at runtime. So the kconfig option lets us make these two mutually exclusive at compile time.
Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org --- drivers/acpi/Kconfig | 15 ++++--- drivers/acpi/Makefile | 5 ++- drivers/acpi/processor_driver.c | 86 +++++++++++++++++++++++++++-------------- include/acpi/processor.h | 28 +++++++++++++- 4 files changed, 96 insertions(+), 38 deletions(-)
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 114cf48..d6e2a86 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -189,17 +189,20 @@ config ACPI_DOCK This driver supports ACPI-controlled docking stations and removable drive bays such as the IBM Ultrabay and the Dell Module Bay.
+config ACPI_CPU_FREQ_PSS + bool + select THERMAL + config ACPI_PROCESSOR tristate "Processor" - select THERMAL - select CPU_IDLE depends on X86 || IA64 + select CPU_IDLE + select ACPI_CPU_FREQ_PSS default y help - This driver installs ACPI as the idle handler for Linux and uses - ACPI C2 and C3 processor states to save power on systems that - support it. It is required by several flavors of cpufreq - performance-state drivers. + This driver adds support for the ACPI Processor package. It is required + by several flavors of cpufreq performance-state, thermal, throttling and + idle drivers.
To compile this driver as a module, choose M here: the module will be called processor. diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 8321430..7e97aef 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -80,8 +80,9 @@ obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o obj-$(CONFIG_ACPI_BGRT) += bgrt.o
# processor has its own "processor." module_param namespace -processor-y := processor_driver.o processor_throttling.o -processor-y += processor_idle.o processor_thermal.o +processor-y := processor_driver.o processor_idle.o +processor-$(CONFIG_ACPI_CPU_FREQ_PSS) += processor_throttling.o \ + processor_thermal.o processor-$(CONFIG_CPU_FREQ) += processor_perflib.o
obj-$(CONFIG_ACPI_PROCESSOR_AGGREGATOR) += acpi_pad.o diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index d9f7158..16d44ad 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -163,34 +163,24 @@ static struct notifier_block __refdata acpi_cpu_notifier = { .notifier_call = acpi_cpu_soft_notify, };
-static int __acpi_processor_start(struct acpi_device *device) +#ifdef CONFIG_ACPI_CPU_FREQ_PSS +static int acpi_pss_perf_init(struct acpi_processor *pr, + 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; - -#ifdef CONFIG_CPU_FREQ acpi_processor_ppc_has_changed(pr, 0); -#endif + acpi_processor_get_throttling_info(pr);
if (pr->flags.throttling) pr->flags.limit = 1;
- 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); if (IS_ERR(pr->cdev)) { result = PTR_ERR(pr->cdev); - goto err_power_exit; + return result; }
dev_dbg(&device->dev, "registered as cooling_device%d\n", @@ -204,6 +194,7 @@ static int __acpi_processor_start(struct acpi_device *device) "Failed to create sysfs link 'thermal_cooling'\n"); goto err_thermal_unregister; } + result = sysfs_create_link(&pr->cdev->device.kobj, &device->dev.kobj, "device"); @@ -213,17 +204,61 @@ static int __acpi_processor_start(struct acpi_device *device) goto err_remove_sysfs_thermal; }
- status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, - acpi_processor_notify, device); - if (ACPI_SUCCESS(status)) - return 0; - sysfs_remove_link(&pr->cdev->device.kobj, "device"); err_remove_sysfs_thermal: sysfs_remove_link(&device->dev.kobj, "thermal_cooling"); err_thermal_unregister: thermal_cooling_device_unregister(pr->cdev); - err_power_exit: + + 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; + + 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; + +err_power_exit: acpi_processor_power_exit(pr); return result; } @@ -252,15 +287,10 @@ static int acpi_processor_stop(struct device *dev) pr = acpi_driver_data(device); if (!pr) return 0; - acpi_processor_power_exit(pr);
- 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; - } + acpi_pss_perf_exit(pr, device); + return 0; }
diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 4188a4d..b6c9178 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -318,6 +318,7 @@ int acpi_get_cpuid(acpi_handle, int type, u32 acpi_id); void acpi_processor_set_pdc(acpi_handle handle);
/* in processor_throttling.c */ +#ifdef CONFIG_ACPI_CPU_FREQ_PSS int acpi_processor_tstate_has_changed(struct acpi_processor *pr); int acpi_processor_get_throttling_info(struct acpi_processor *pr); extern int acpi_processor_set_throttling(struct acpi_processor *pr, @@ -330,6 +331,29 @@ extern void acpi_processor_reevaluate_tstate(struct acpi_processor *pr, unsigned long action); extern const struct file_operations acpi_processor_throttling_fops; extern void acpi_processor_throttling_init(void); +#else +static inline int acpi_processor_tstate_has_changed(struct acpi_processor *pr) +{ + return 0; +} + +static inline int acpi_processor_get_throttling_info(struct acpi_processor *pr) +{ + return -ENODEV; +} + +static inline int acpi_processor_set_throttling(struct acpi_processor *pr, + int state, bool force) +{ + return -ENODEV; +} + +static inline void acpi_processor_reevaluate_tstate(struct acpi_processor *pr, + unsigned long action) {} + +static inline void acpi_processor_throttling_init(void) {} +#endif /* CONFIG_ACPI_CPU_FREQ_PSS */ + /* in processor_idle.c */ int acpi_processor_power_init(struct acpi_processor *pr); int acpi_processor_power_exit(struct acpi_processor *pr); @@ -348,7 +372,7 @@ static inline void acpi_processor_syscore_exit(void) {} /* in processor_thermal.c */ int acpi_processor_get_limit_info(struct acpi_processor *pr); extern const struct thermal_cooling_device_ops processor_cooling_ops; -#ifdef CONFIG_CPU_FREQ +#if defined(CONFIG_ACPI_CPU_FREQ_PSS) & defined(CONFIG_CPU_FREQ) void acpi_thermal_cpufreq_init(void); void acpi_thermal_cpufreq_exit(void); #else @@ -360,6 +384,6 @@ static inline void acpi_thermal_cpufreq_exit(void) { return; } -#endif +#endif /* CONFIG_ACPI_CPU_FREQ_PSS */
#endif