From aa297292d708e89773b3b2cdcaf33f01bfa095d8 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Fri, 17 Jun 2016 01:22:51 -0400 Subject: x86/tsc: Enumerate SKL cpu_khz and tsc_khz via CPUID Skylake CPU base-frequency and TSC frequency may differ by up to 2%. Enumerate CPU and TSC frequencies separately, allowing cpu_khz and tsc_khz to differ. The existing CPU frequency calibration mechanism is unchanged. However, CPUID extensions are preferred, when available. CPUID.0x16 is preferred over MSR and timer calibration for CPU frequency discovery. CPUID.0x15 takes precedence over CPU-frequency for TSC frequency discovery. Signed-off-by: Len Brown Reviewed-by: Thomas Gleixner Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/b27ec289fd005833b27d694d9c2dbb716c5cdff7.1466138954.git.len.brown@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/x86_init.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/kernel/x86_init.c') diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c index dad5fe9633a3..58b459296e13 100644 --- a/arch/x86/kernel/x86_init.c +++ b/arch/x86/kernel/x86_init.c @@ -92,6 +92,7 @@ static void default_nmi_init(void) { }; static int default_i8042_detect(void) { return 1; }; struct x86_platform_ops x86_platform = { + .calibrate_cpu = native_calibrate_cpu, .calibrate_tsc = native_calibrate_tsc, .get_wallclock = mach_get_cmos_time, .set_wallclock = mach_set_rtc_mmss, -- cgit v1.2.3