summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/x86_init.c
diff options
context:
space:
mode:
authorLen Brown <len.brown@intel.com>2016-06-17 08:22:51 +0300
committerIngo Molnar <mingo@kernel.org>2016-07-11 22:30:13 +0300
commitaa297292d708e89773b3b2cdcaf33f01bfa095d8 (patch)
tree2930daf94d5bba00f8766f2ffcdaf6ba0c8d16ea /arch/x86/kernel/x86_init.c
parent02c0cd2dcf7fdc47d054b855b148ea8b82dbb7eb (diff)
downloadlinux-aa297292d708e89773b3b2cdcaf33f01bfa095d8.tar.xz
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 <len.brown@intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/b27ec289fd005833b27d694d9c2dbb716c5cdff7.1466138954.git.len.brown@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/x86_init.c')
-rw-r--r--arch/x86/kernel/x86_init.c1
1 files changed, 1 insertions, 0 deletions
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,