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| author | Marcelo Tosatti <mtosatti@redhat.com> | 2012-11-27 23:28:52 -0200 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-11-27 23:29:08 -0200 |
| commit | 2697902be89d7f38e9736dfe946cd0e5d4f47b80 (patch) | |
| tree | c1588307560a7a4ecd05bc3d1eff8a36bf3b4fe3 | |
| parent | dce2db0a35197e2f4421245079f19ab753e97348 (diff) | |
| download | linux-2697902be89d7f38e9736dfe946cd0e5d4f47b80.tar.bz2 | |
x86: pvclock: introduce helper to read flags
Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
| -rw-r--r-- | arch/x86/include/asm/pvclock.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/pvclock.c | 13 |
2 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 47e25d464104..ea27a8dd189c 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/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); +u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); void pvclock_set_flags(u8 flags); unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); void pvclock_read_wallclock(struct pvclock_wall_clock *wall, diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c index a7d90910c61a..c8fb043a8695 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c @@ -45,6 +45,19 @@ void pvclock_resume(void) atomic64_set(&last_value, 0); } +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); + } while ((src->version & 1) || version != src->version); + + return flags & valid_flags; +} + cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) { unsigned version; |