diff options
Diffstat (limited to 'arch/x86/kernel/tsc.c')
| -rw-r--r-- | arch/x86/kernel/tsc.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index fdd4c1078632..49d925043171 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -41,6 +41,7 @@ EXPORT_SYMBOL(tsc_khz); * TSC can be unstable due to cpufreq or due to unsynced TSCs */ static int __read_mostly tsc_unstable; +static unsigned int __initdata tsc_early_khz; static DEFINE_STATIC_KEY_FALSE(__use_tsc); @@ -59,6 +60,12 @@ struct cyc2ns { static DEFINE_PER_CPU_ALIGNED(struct cyc2ns, cyc2ns); +static int __init tsc_early_khz_setup(char *buf) +{ + return kstrtouint(buf, 0, &tsc_early_khz); +} +early_param("tsc_early_khz", tsc_early_khz_setup); + __always_inline void cyc2ns_read_begin(struct cyc2ns_data *data) { int seq, idx; @@ -1412,7 +1419,10 @@ static bool __init determine_cpu_tsc_frequencies(bool early) if (early) { cpu_khz = x86_platform.calibrate_cpu(); - tsc_khz = x86_platform.calibrate_tsc(); + if (tsc_early_khz) + tsc_khz = tsc_early_khz; + else + tsc_khz = x86_platform.calibrate_tsc(); } else { /* We should not be here with non-native cpu calibration */ WARN_ON(x86_platform.calibrate_cpu != native_calibrate_cpu); |