x86: Add cpu capability flag X86_FEATURE_NONSTOP_TSC_S3
authorFeng Tang <feng.tang@intel.com>
Tue, 12 Mar 2013 03:56:45 +0000 (11:56 +0800)
committerJohn Stultz <john.stultz@linaro.org>
Fri, 15 Mar 2013 23:50:26 +0000 (16:50 -0700)
commitc54fdbb2823d96b842d00c548e14dbc0dd37831d
tree1193dec6db8b75b990c0375ac8a55bfd2ffc034c
parent3195ef59cb42cda3aeeb24a7fd2ba1b900c4a3cc
x86: Add cpu capability flag X86_FEATURE_NONSTOP_TSC_S3

On some new Intel Atom processors (Penwell and Cloverview), there is
a feature that the TSC won't stop in S3 state, say the TSC value
won't be reset to 0 after resume. This feature makes TSC a more reliable
clocksource and could benefit the timekeeping code during system
suspend/resume cycle, so add a flag for it.

Signed-off-by: Feng Tang <feng.tang@intel.com>
[jstultz: Fix checkpatch warning]
Signed-off-by: John Stultz <john.stultz@linaro.org>
arch/x86/include/asm/cpufeature.h
arch/x86/kernel/cpu/intel.c