Merge remote-tracking branches 'spi/topic/pxa2xx', 'spi/topic/rockchip', 'spi/topic...

[cascardo/linux.git] / arch / x86 / kernel / pvclock.c

diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index 99bfc02..06c58ce 100644 (file)
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -61,11 +61,16 @@ void pvclock_resume(void)
 u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src)
 {
        unsigned version;
-       cycle_t ret;
        u8 flags;
 
        do {
-               version = __pvclock_read_cycles(src, &ret, &flags);
+               version = src->version;
+               /* Make the latest version visible */
+               smp_rmb();
+
+               flags = src->flags;
+               /* Make sure that the version double-check is last. */
+               smp_rmb();
        } while ((src->version & 1) || version != src->version);
 
        return flags & valid_flags;
@@ -80,6 +85,8 @@ cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
 
        do {
                version = __pvclock_read_cycles(src, &ret, &flags);
+               /* Make sure that the version double-check is last. */
+               smp_rmb();
        } while ((src->version & 1) || version != src->version);
 
        if (unlikely((flags & PVCLOCK_GUEST_STOPPED) != 0)) {