timekeeping: Increase granularity of read_persistent_clock()

The persistent clock of some architectures (e.g. s390) have a
better granularity than seconds. To reduce the delta between the
host clock and the guest clock in a virtualized system change the 
read_persistent_clock function to return a struct timespec.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
LKML-Reference: <20090814134811.013873340@de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c
index 0b97d47691fc..3c6f190aa61c 100644
--- a/arch/mips/mti-malta/malta-time.c
+++ b/arch/mips/mti-malta/malta-time.c
@@ -100,9 +100,10 @@ static unsigned int __init estimate_cpu_frequency(void)
         return count;
 }
 
-unsigned long read_persistent_clock(void)
+void read_persistent_clock(struct timespec *ts)
 {
-        return mc146818_get_cmos_time();
+        ts->tv_sec = mc146818_get_cmos_time();
+        ts->tv_nsec = 0;
 }
 
 static void __init plat_perf_setup(void)