x86: paravirt: factor out cpu_khz to common code
KVM intends to use paravirt code to calibrate khz. Xen
current code will do just fine. So as a first step, factor out
code to pvclock.c.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index 05fbe9a..1c54b5f 100644
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -97,6 +97,18 @@
return dst->version;
}
+unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src)
+{
+ u64 tsc_khz = 1000000ULL << 32;
+
+ do_div(tsc_khz, src->tsc_to_system_mul);
+ if (src->tsc_shift < 0)
+ tsc_khz <<= -src->tsc_shift;
+ else
+ tsc_khz >>= src->tsc_shift;
+ return tsc_khz;
+}
+
cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
{
struct pvclock_shadow_time shadow;