Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754189Ab0G1TJl (ORCPT ); Wed, 28 Jul 2010 15:09:41 -0400 Received: from mga03.intel.com ([143.182.124.21]:61943 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752235Ab0G1TJV (ORCPT ); Wed, 28 Jul 2010 15:09:21 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.55,275,1278313200"; d="scan'208";a="305514052" From: "Fenghua Yu" To: "Ingo Molnar" , "Thomas Gleixner" , "H Peter Anvin" , "Len Brown" , "Guenter Roeck" , "Chen Gong" , "Jean Delvare" , "Huaxu Wan" Cc: "linux-kernel" , "lm-sensors" , Fenghua Yu Subject: [PATH V2 5/5] Package Level Thermal Control and Power Limit Notification: pkgtemp doc Date: Wed, 28 Jul 2010 12:00:53 -0700 Message-Id: <1280343653-26380-6-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 1.7.2 In-Reply-To: <1280343653-26380-1-git-send-email-fenghua.yu@intel.com> References: <1280343653-26380-1-git-send-email-fenghua.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2402 Lines: 62 From: Fenghua Yu Document for package level thermal hwmon driver. Signed-off-by: Fenghua Yu Reviewed-by: Len Brown Reviewed-by: Guenter Roeck --- Documentation/hwmon/pkgtemp | 36 ++++++++++++++++++++++++++++++++++++ 1 files changed, 36 insertions(+), 0 deletions(-) create mode 100644 Documentation/hwmon/pkgtemp diff --git a/Documentation/hwmon/pkgtemp b/Documentation/hwmon/pkgtemp new file mode 100644 index 0000000..c8e1fb0 --- /dev/null +++ b/Documentation/hwmon/pkgtemp @@ -0,0 +1,36 @@ +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. -- 1.7.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/