diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-06 13:02:58 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-06 13:02:58 -0400 |
commit | a5e11599da95fbe8425db0cfd01a581d7412d0c9 (patch) | |
tree | 45fccb4b27a1068cec8dc8283260893b60ca46d2 /Documentation | |
parent | 0f477dd0851bdcee82923da66a7fc4a44cb1bc3d (diff) | |
parent | a3159864f2978bf2ace9cc787d73d315c98bbf9a (diff) |
Merge branch 'x86-hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, hwmon: Package Level Thermal/Power: pkgtemp documentation
x86, hwmon: Package Level Thermal/Power: power limit
x86, hwmon: Package Level Thermal/Power: thermal throttling handler
x86, hwmon: Package Level Thermal/Power: pkgtemp hwmon driver
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/hwmon/pkgtemp | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/hwmon/pkgtemp b/Documentation/hwmon/pkgtemp new file mode 100644 index 000000000000..c8e1fb0fadd3 --- /dev/null +++ b/Documentation/hwmon/pkgtemp | |||
@@ -0,0 +1,36 @@ | |||
1 | Kernel driver pkgtemp | ||
2 | ====================== | ||
3 | |||
4 | Supported chips: | ||
5 | * Intel family | ||
6 | Prefix: 'pkgtemp' | ||
7 | CPUID: | ||
8 | Datasheet: Intel 64 and IA-32 Architectures Software Developer's Manual | ||
9 | Volume 3A: System Programming Guide | ||
10 | |||
11 | Author: Fenghua Yu | ||
12 | |||
13 | Description | ||
14 | ----------- | ||
15 | |||
16 | This driver permits reading package level temperature sensor embedded inside | ||
17 | Intel CPU package. The sensors can be in core, uncore, memory controller, or | ||
18 | other components in a package. The feature is first implemented in Intel Sandy | ||
19 | Bridge platform. | ||
20 | |||
21 | Temperature is measured in degrees Celsius and measurement resolution is | ||
22 | 1 degree C. Valid temperatures are from 0 to TjMax degrees C, because the actual | ||
23 | value of temperature register is in fact a delta from TjMax. | ||
24 | |||
25 | Temperature known as TjMax is the maximum junction temperature of package. | ||
26 | We get this from MSR_IA32_TEMPERATURE_TARGET. If the MSR is not accessible, | ||
27 | we define TjMax as 100 degrees Celsius. At this temperature, protection | ||
28 | mechanism will perform actions to forcibly cool down the package. Alarm | ||
29 | may be raised, if the temperature grows enough (more than TjMax) to trigger | ||
30 | the Out-Of-Spec bit. Following table summarizes the exported sysfs files: | ||
31 | |||
32 | temp1_input - Package temperature (in millidegrees Celsius). | ||
33 | temp1_max - All cooling devices should be turned on. | ||
34 | temp1_crit - Maximum junction temperature (in millidegrees Celsius). | ||
35 | temp1_crit_alarm - Set when Out-of-spec bit is set, never clears. | ||
36 | Correct CPU operation is no longer guaranteed. | ||