x86: tsc: Add support for new S3_NONSTOP feature

Add support for new S3_NONSTOP feature

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 4b9ea10..098b3cf 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -768,7 +768,8 @@ static cycle_t read_tsc(struct clocksource *cs)
 
 static void resume_tsc(struct clocksource *cs)
 {
-       clocksource_tsc.cycle_last = 0;
+       if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC_S3))
+               clocksource_tsc.cycle_last = 0;
 }
 
 static struct clocksource clocksource_tsc = {
@@ -939,6 +940,9 @@ static int __init init_tsc_clocksource(void)
                clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
        }
 
+       if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC_S3))
+               clocksource_tsc.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
+
        /*
         * Trust the results of the earlier calibration on systems
         * exporting a reliable TSC.