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Commit d9460fd2 authored by Zhang Rui's avatar Zhang Rui Committed by Len Brown
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ACPI: register ACPI Processor as generic thermal cooling device 



Register ACPI processor as thermal cooling devices.
A combination of processor T-state and P-state are used for thermal throttling.
the processor will reduce the frequency first and then set the T-state.

we use cpufreq_thermal_reduction_pctg to calculate the cpufreq limit,
and call cpufreq_verify_with_limit to set the cpufreq limit.
if cpufreq driver is loaded, then we have four cooling state for cpufreq control.
cooling state 0: cpufreq limit == max_freq
cooling state 1: cpufreq limit == max_freq * 80%
cooling state 2: cpufreq limit == max_freq * 60%
cooling state 3: cpufreq limit == max_freq * 40%

after the cpufreq limit is set to 40 percentage of the max_freq,
we use T-state for cooling.

eg. a processor has P-state support, and it has 8 T-state (T0-T7),
the max_state of the proceesor is 10:

state	cpufreq-limit  T-state
0:	max_freq	T0
1:	max_freq * 80%	T0
2:	max_freq * 60%	T0
3:	max_freq * 40%	T0
4:	max_freq * 40%	T1
5:	max_freq * 40%	T2
6:	max_freq * 40%	T3
7:	max_freq * 40%	T4
8:	max_freq * 40%	T5
9:	max_freq * 40%	T6
10:	max_freq * 40%	T7

Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Signed-off-by: default avatarZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: default avatarThomas Sujith <sujith.thomas@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 05a83d97

drivers/acpi/processor_core.c

+23 −0
Original line number Diff line number Diff line
@@ -668,6 +668,24 @@ static int __cpuinit acpi_processor_start(struct acpi_device *device) 


	acpi_processor_power_init(pr, device);



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

						&processor_cooling_ops);

	if (pr->cdev)

		printk(KERN_INFO PREFIX

			"%s is registered as cooling_device%d\n",

			device->dev.bus_id, pr->cdev->id);

	else

		goto end;



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

					"thermal_cooling");

	if (result)

		return result;

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

					"device");

	if (result)

		return result;



	if (pr->flags.throttling) {

		printk(KERN_INFO PREFIX "%s [%s] (supports",

		       acpi_device_name(device), acpi_device_bid(device));
@@ -791,6 +809,11 @@ static int acpi_processor_remove(struct acpi_device *device, int type) 


	acpi_processor_remove_fs(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;



	processors[pr->id] = NULL;



	kfree(pr);

drivers/acpi/processor_thermal.c

+129 −5
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#include <linux/cpufreq.h>

#include <linux/proc_fs.h>

#include <linux/seq_file.h>

#include <linux/sysdev.h>



#include <asm/uaccess.h>
@@ -93,6 +94,9 @@ static int acpi_processor_apply_limit(struct acpi_processor *pr) 
 * _any_ cpufreq driver and not only the acpi-cpufreq driver.

 */



#define CPUFREQ_THERMAL_MIN_STEP 0

#define CPUFREQ_THERMAL_MAX_STEP 3



static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];

static unsigned int acpi_thermal_cpufreq_is_init = 0;
@@ -109,8 +113,9 @@ static int acpi_thermal_cpufreq_increase(unsigned int cpu) 
	if (!cpu_has_cpufreq(cpu))

		return -ENODEV;



	if (cpufreq_thermal_reduction_pctg[cpu] < 60) {

		cpufreq_thermal_reduction_pctg[cpu] += 20;

	if (cpufreq_thermal_reduction_pctg[cpu] <

		CPUFREQ_THERMAL_MAX_STEP) {

		cpufreq_thermal_reduction_pctg[cpu]++;

		cpufreq_update_policy(cpu);

		return 0;

	}
@@ -123,8 +128,9 @@ static int acpi_thermal_cpufreq_decrease(unsigned int cpu) 
	if (!cpu_has_cpufreq(cpu))

		return -ENODEV;



	if (cpufreq_thermal_reduction_pctg[cpu] > 20)

		cpufreq_thermal_reduction_pctg[cpu] -= 20;

	if (cpufreq_thermal_reduction_pctg[cpu] >

		(CPUFREQ_THERMAL_MIN_STEP + 1))

		cpufreq_thermal_reduction_pctg[cpu]--;

	else

		cpufreq_thermal_reduction_pctg[cpu] = 0;

	cpufreq_update_policy(cpu);
@@ -143,7 +149,7 @@ static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb, 


	max_freq =

	    (policy->cpuinfo.max_freq *

	     (100 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 100;

	     (100 - cpufreq_thermal_reduction_pctg[policy->cpu] * 20)) / 100;



	cpufreq_verify_within_limits(policy, 0, max_freq);
@@ -155,6 +161,32 @@ static struct notifier_block acpi_thermal_cpufreq_notifier_block = { 
	.notifier_call = acpi_thermal_cpufreq_notifier,

};



static int cpufreq_get_max_state(unsigned int cpu)

{

	if (!cpu_has_cpufreq(cpu))

		return 0;



	return CPUFREQ_THERMAL_MAX_STEP;

}



static int cpufreq_get_cur_state(unsigned int cpu)

{

	if (!cpu_has_cpufreq(cpu))

		return 0;



	return cpufreq_thermal_reduction_pctg[cpu];

}



static int cpufreq_set_cur_state(unsigned int cpu, int state)

{

	if (!cpu_has_cpufreq(cpu))

		return 0;



	cpufreq_thermal_reduction_pctg[cpu] = state;

	cpufreq_update_policy(cpu);

	return 0;

}



void acpi_thermal_cpufreq_init(void)

{

	int i;
@@ -179,6 +211,20 @@ void acpi_thermal_cpufreq_exit(void) 
}



#else				/* ! CONFIG_CPU_FREQ */

static int cpufreq_get_max_state(unsigned int cpu)

{

	return 0;

}



static int cpufreq_get_cur_state(unsigned int cpu)

{

	return 0;

}



static int cpufreq_set_cur_state(unsigned int cpu, int state)

{

	return 0;

}



static int acpi_thermal_cpufreq_increase(unsigned int cpu)

{
@@ -310,6 +356,84 @@ int acpi_processor_get_limit_info(struct acpi_processor *pr) 
	return 0;

}



/* thermal coolign device callbacks */

static int acpi_processor_max_state(struct acpi_processor *pr)

{

	int max_state = 0;



	/*

	 * There exists four states according to

	 * cpufreq_thermal_reduction_ptg. 0, 1, 2, 3

	 */

	max_state += cpufreq_get_max_state(pr->id);

	if (pr->flags.throttling)

		max_state += (pr->throttling.state_count -1);



	return max_state;

}

static int

processor_get_max_state(struct thermal_cooling_device *cdev, char *buf)

{

	struct acpi_device *device = cdev->devdata;

	struct acpi_processor *pr = acpi_driver_data(device);



	if (!device || !pr)

		return -EINVAL;



	return sprintf(buf, "%d\n", acpi_processor_max_state(pr));

}



static int

processor_get_cur_state(struct thermal_cooling_device *cdev, char *buf)

{

	struct acpi_device *device = cdev->devdata;

	struct acpi_processor *pr = acpi_driver_data(device);

	int cur_state;



	if (!device || !pr)

		return -EINVAL;



	cur_state = cpufreq_get_cur_state(pr->id);

	if (pr->flags.throttling)

		cur_state += pr->throttling.state;



	return sprintf(buf, "%d\n", cur_state);

}



static int

processor_set_cur_state(struct thermal_cooling_device *cdev, unsigned int state)

{

	struct acpi_device *device = cdev->devdata;

	struct acpi_processor *pr = acpi_driver_data(device);

	int result = 0;

	int max_pstate;



	if (!device || !pr)

		return -EINVAL;



	max_pstate = cpufreq_get_max_state(pr->id);



	if (state > acpi_processor_max_state(pr))

		return -EINVAL;



	if (state <= max_pstate) {

		if (pr->flags.throttling && pr->throttling.state)

			result = acpi_processor_set_throttling(pr, 0);

		cpufreq_set_cur_state(pr->id, state);

	} else {

		cpufreq_set_cur_state(pr->id, max_pstate);

		result = acpi_processor_set_throttling(pr,

				state - max_pstate);

	}

	return result;

}



struct thermal_cooling_device_ops processor_cooling_ops = {

	.get_max_state = processor_get_max_state,

	.get_cur_state = processor_get_cur_state,

	.set_cur_state = processor_set_cur_state,

};



/* /proc interface */



static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset)

include/acpi/processor.h

+3 −3
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
#include <linux/kernel.h>

#include <linux/cpu.h>

#include <linux/cpuidle.h>



#include <linux/thermal.h>

#include <asm/acpi.h>



#define ACPI_PROCESSOR_BUSY_METRIC	10
@@ -218,7 +218,7 @@ struct acpi_processor { 
	struct acpi_processor_performance *performance;

	struct acpi_processor_throttling throttling;

	struct acpi_processor_limit limit;



	struct thermal_cooling_device *cdev;

	/* the _PDC objects for this processor, if any */

	struct acpi_object_list *pdc;

};
@@ -330,7 +330,7 @@ extern struct cpuidle_driver acpi_idle_driver; 
/* in processor_thermal.c */

int acpi_processor_get_limit_info(struct acpi_processor *pr);

extern struct file_operations acpi_processor_limit_fops;



extern struct thermal_cooling_device_ops processor_cooling_ops;

#ifdef CONFIG_CPU_FREQ

void acpi_thermal_cpufreq_init(void);

void acpi_thermal_cpufreq_exit(void);