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ACPI: register ACPI Processor as generic thermal cooling device

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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: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Thomas Sujith <sujith.thomas@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Zhang Rui
2008-01-17 15:51:23 +08:00
committed by Len Brown
parent 05a83d9722
commit d9460fd227
3 changed files with 155 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

134
drivers/acpi/processor_thermal.c
View File

@@ -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)