37 lines
1.5 KiB
Plaintext
37 lines
1.5 KiB
Plaintext
|
Kernel driver pkgtemp
|
||
|
======================
|
||
|
|
||
|
Supported chips:
|
||
|
* Intel family
|
||
|
Prefix: 'pkgtemp'
|
||
|
CPUID:
|
||
|
Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual
|
||
|
Volume 3A: System Programming Guide
|
||
|
|
||
|
Author: Fenghua Yu
|
||
|
|
||
|
Description
|
||
|
-----------
|
||
|
|
||
|
This driver permits reading package level temperature sensor embedded inside
|
||
|
Intel CPU package. The sensors can be in core, uncore, memory controller, or
|
||
|
other components in a package. The feature is first implemented in Intel Sandy
|
||
|
Bridge platform.
|
||
|
|
||
|
Temperature is measured in degrees Celsius and measurement resolution is
|
||
|
1 degree C. Valid temperatures are from 0 to TjMax degrees C, because the actual
|
||
|
value of temperature register is in fact a delta from TjMax.
|
||
|
|
||
|
Temperature known as TjMax is the maximum junction temperature of package.
|
||
|
We get this from MSR_IA32_TEMPERATURE_TARGET. If the MSR is not accessible,
|
||
|
we define TjMax as 100 degrees Celsius. At this temperature, protection
|
||
|
mechanism will perform actions to forcibly cool down the package. Alarm
|
||
|
may be raised, if the temperature grows enough (more than TjMax) to trigger
|
||
|
the Out-Of-Spec bit. Following table summarizes the exported sysfs files:
|
||
|
|
||
|
temp1_input - Package temperature (in millidegrees Celsius).
|
||
|
temp1_max - All cooling devices should be turned on.
|
||
|
temp1_crit - Maximum junction temperature (in millidegrees Celsius).
|
||
|
temp1_crit_alarm - Set when Out-of-spec bit is set, never clears.
|
||
|
Correct CPU operation is no longer guaranteed.
|