x86: pvclock: create helper for pvclock data retrieval
Originally from Jeremy Fitzhardinge.
So code can be reused.
Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index d59e606..a7d9091 100644
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -26,13 +26,6 @@
valid_flags = flags;
}
-static u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
-{
- u64 delta = native_read_tsc() - src->tsc_timestamp;
- return pvclock_scale_delta(delta, src->tsc_to_system_mul,
- src->tsc_shift);
-}
-
unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src)
{
u64 pv_tsc_khz = 1000000ULL << 32;
@@ -55,17 +48,12 @@
cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
{
unsigned version;
- cycle_t ret, offset;
+ cycle_t ret;
u64 last;
u8 flags;
do {
- version = src->version;
- rdtsc_barrier();
- offset = pvclock_get_nsec_offset(src);
- ret = src->system_time + offset;
- flags = src->flags;
- rdtsc_barrier();
+ version = __pvclock_read_cycles(src, &ret, &flags);
} while ((src->version & 1) || version != src->version);
if ((valid_flags & PVCLOCK_TSC_STABLE_BIT) &&
