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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
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23
drivers/acpi/processor_core.c
View File

@@ -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);