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 (file)
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -97,6 +97,18 @@ static unsigned pvclock_get_time_values(struct pvclock_shadow_time *dst,
        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;

diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 004ba86..c9f7cda 100644 (file)
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -198,17 +198,10 @@ unsigned long long xen_sched_clock(void)
 /* Get the TSC speed from Xen */
 unsigned long xen_tsc_khz(void)
 {
-       u64 xen_khz = 1000000ULL << 32;
-       const struct pvclock_vcpu_time_info *info =
+       struct pvclock_vcpu_time_info *info =
                &HYPERVISOR_shared_info->vcpu_info[0].time;
 
-       do_div(xen_khz, info->tsc_to_system_mul);
-       if (info->tsc_shift < 0)
-               xen_khz <<= -info->tsc_shift;
-       else
-               xen_khz >>= info->tsc_shift;
-
-       return xen_khz;
+       return pvclock_tsc_khz(info);
 }
 
 cycle_t xen_clocksource_read(void)

diff --git a/include/asm-x86/pvclock.h b/include/asm-x86/pvclock.h
index 1a38f68..ad29e27 100644 (file)
--- a/include/asm-x86/pvclock.h
+++ b/include/asm-x86/pvclock.h
@@ -6,6 +6,7 @@
 
 /* some helper functions for xen and kvm pv clock sources */
 cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
+unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
 void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
                            struct pvclock_vcpu_time_info *vcpu,
                            struct timespec *ts);