Commit 239708a3 authored by Ashwin Chaugule's avatar Ashwin Chaugule Committed by Rafael J. Wysocki
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ACPI: Split out ACPI PSS from ACPI Processor driver 



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.

A future commit will introduce support for CPPC: A newer method of
controlling CPU performance. The OS is not expected to support
CPPC and PSS at the same time, so the Kconfig option lets us make
the two mutually exclusive at compile time.

Signed-off-by: default avatarAshwin Chaugule <ashwin.chaugule@linaro.org>
[ rjw: Changelog ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent d3c68f21

drivers/acpi/Kconfig

+9 −6
Original line number Original line Diff line number Diff line
@@ -189,17 +189,20 @@ config ACPI_DOCK 
	  This driver supports ACPI-controlled docking stations and removable

	  This driver supports ACPI-controlled docking stations and removable

	  drive bays such as the IBM Ultrabay and the Dell Module Bay.

	  drive bays such as the IBM Ultrabay and the Dell Module Bay.





config ACPI_CPU_FREQ_PSS

	bool

	select THERMAL



config ACPI_PROCESSOR

config ACPI_PROCESSOR

	tristate "Processor"

	tristate "Processor"

	select THERMAL

	select CPU_IDLE

	depends on X86 || IA64

	depends on X86 || IA64

	select CPU_IDLE

	select ACPI_CPU_FREQ_PSS

	default y

	default y

	help

	help

	  This driver installs ACPI as the idle handler for Linux and uses

	  This driver adds support for the ACPI Processor package. It is required

	  ACPI C2 and C3 processor states to save power on systems that

	  by several flavors of cpufreq performance-state, thermal, throttling and

	  support it.  It is required by several flavors of cpufreq

	  idle drivers.

	  performance-state drivers.





	  To compile this driver as a module, choose M here:

	  To compile this driver as a module, choose M here:

	  the module will be called processor.

	  the module will be called processor.

drivers/acpi/Makefile

+3 −2
Original line number Original line Diff line number Diff line
@@ -80,8 +80,9 @@ obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o 
obj-$(CONFIG_ACPI_BGRT)		+= bgrt.o

obj-$(CONFIG_ACPI_BGRT)		+= bgrt.o





# processor has its own "processor." module_param namespace

# processor has its own "processor." module_param namespace

processor-y			:= processor_driver.o processor_throttling.o

processor-y			:= processor_driver.o processor_idle.o

processor-y			+= processor_idle.o processor_thermal.o

processor-$(CONFIG_ACPI_CPU_FREQ_PSS)	+= processor_throttling.o	\

	processor_thermal.o

processor-$(CONFIG_CPU_FREQ)	+= processor_perflib.o

processor-$(CONFIG_CPU_FREQ)	+= processor_perflib.o





obj-$(CONFIG_ACPI_PROCESSOR_AGGREGATOR) += acpi_pad.o

obj-$(CONFIG_ACPI_PROCESSOR_AGGREGATOR) += acpi_pad.o

drivers/acpi/processor_driver.c

+58 −28
Original line number Original line Diff line number Diff line
@@ -163,34 +163,24 @@ static struct notifier_block acpi_cpu_notifier = { 
	    .notifier_call = acpi_cpu_soft_notify,

	    .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;

	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);

	acpi_processor_ppc_has_changed(pr, 0);

#endif



	acpi_processor_get_throttling_info(pr);

	acpi_processor_get_throttling_info(pr);





	if (pr->flags.throttling)

	if (pr->flags.throttling)

		pr->flags.limit = 1;

		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,

	pr->cdev = thermal_cooling_device_register("Processor", device,

						   &processor_cooling_ops);

						   &processor_cooling_ops);

	if (IS_ERR(pr->cdev)) {

	if (IS_ERR(pr->cdev)) {

		result = PTR_ERR(pr->cdev);

		result = PTR_ERR(pr->cdev);

		goto err_power_exit;

		return result;

	}

	}





	dev_dbg(&device->dev, "registered as cooling_device%d\n",

	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");

			"Failed to create sysfs link 'thermal_cooling'\n");

		goto err_thermal_unregister;

		goto err_thermal_unregister;

	}

	}



	result = sysfs_create_link(&pr->cdev->device.kobj,

	result = sysfs_create_link(&pr->cdev->device.kobj,

				   &device->dev.kobj,

				   &device->dev.kobj,

				   "device");

				   "device");
@@ -213,16 +204,60 @@ static int __acpi_processor_start(struct acpi_device *device) 
		goto err_remove_sysfs_thermal;

		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");

	sysfs_remove_link(&pr->cdev->device.kobj, "device");

 err_remove_sysfs_thermal:

 err_remove_sysfs_thermal:

	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");

	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");

 err_thermal_unregister:

 err_thermal_unregister:

	thermal_cooling_device_unregister(pr->cdev);

	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;



	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:

err_power_exit:

	acpi_processor_power_exit(pr);

	acpi_processor_power_exit(pr);

	return result;

	return result;
@@ -252,15 +287,10 @@ static int acpi_processor_stop(struct device *dev) 
	pr = acpi_driver_data(device);

	pr = acpi_driver_data(device);

	if (!pr)

	if (!pr)

		return 0;

		return 0;



	acpi_processor_power_exit(pr);

	acpi_processor_power_exit(pr);





	if (pr->cdev) {

	acpi_pss_perf_exit(pr, device);

		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;

	}

	return 0;

	return 0;

}

}

include/acpi/processor.h

+26 −2
Original line number Original line Diff line number Diff line
@@ -318,6 +318,7 @@ int acpi_get_cpuid(acpi_handle, int type, u32 acpi_id); 
void acpi_processor_set_pdc(acpi_handle handle);

void acpi_processor_set_pdc(acpi_handle handle);





/* in processor_throttling.c */

/* in processor_throttling.c */

#ifdef CONFIG_ACPI_CPU_FREQ_PSS

int acpi_processor_tstate_has_changed(struct acpi_processor *pr);

int acpi_processor_tstate_has_changed(struct acpi_processor *pr);

int acpi_processor_get_throttling_info(struct acpi_processor *pr);

int acpi_processor_get_throttling_info(struct acpi_processor *pr);

extern int acpi_processor_set_throttling(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);

			unsigned long action);

extern const struct file_operations acpi_processor_throttling_fops;

extern const struct file_operations acpi_processor_throttling_fops;

extern void acpi_processor_throttling_init(void);

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 */

/* in processor_idle.c */

int acpi_processor_power_init(struct acpi_processor *pr);

int acpi_processor_power_init(struct acpi_processor *pr);

int acpi_processor_power_exit(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 */

/* in processor_thermal.c */

int acpi_processor_get_limit_info(struct acpi_processor *pr);

int acpi_processor_get_limit_info(struct acpi_processor *pr);

extern const struct thermal_cooling_device_ops processor_cooling_ops;

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_init(void);

void acpi_thermal_cpufreq_exit(void);

void acpi_thermal_cpufreq_exit(void);

#else

#else
@@ -360,6 +384,6 @@ static inline void acpi_thermal_cpufreq_exit(void) 
{

{

	return;

	return;

}

}

#endif

#endif	/* CONFIG_ACPI_CPU_FREQ_PSS */





#endif
 
#endif

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