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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2009-08-14 15:47:32 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2009-08-15 10:55:47 +0200 |
| commit | 23970e389e9cee43c4b41023935e1417271708b2 (patch) | |
| tree | d97d299cf74c44cf7ceb4c04c82dafc451fbbfbb /arch/s390 | |
| parent | d4f587c67fc39e0030ddd718675e252e208da4d7 (diff) | |
| download | linux-23970e389e9cee43c4b41023935e1417271708b2.tar.gz linux-23970e389e9cee43c4b41023935e1417271708b2.tar.bz2 linux-23970e389e9cee43c4b41023935e1417271708b2.zip | |
timekeeping: Introduce read_boot_clock
Add the new function read_boot_clock to get the exact time the system
has been started. For architectures without support for exact boot
time a new weak function is added that returns 0. Use the exact boot
time to initialize wall_to_monotonic, or xtime if the read_boot_clock
returned 0.
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: <20090814134811.296703241@de.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kernel/time.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index a94ec48587b4..6bff1a1d9060 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -187,6 +187,11 @@ void read_persistent_clock(struct timespec *ts) tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, ts); } +void read_boot_clock(struct timespec *ts) +{ + tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, ts); +} + static cycle_t read_tod_clock(struct clocksource *cs) { return get_clock(); @@ -243,9 +248,6 @@ void update_vsyscall_tz(void) */ void __init time_init(void) { - struct timespec ts; - unsigned long flags; - /* Reset time synchronization interfaces. */ etr_reset(); stp_reset(); @@ -261,15 +263,6 @@ void __init time_init(void) if (clocksource_register(&clocksource_tod) != 0) panic("Could not register TOD clock source"); - /* - * Reset wall_to_monotonic to the initial timestamp created - * in head.S to get a precise value in /proc/uptime. - */ - write_seqlock_irqsave(&xtime_lock, flags); - tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, &ts); - set_normalized_timespec(&wall_to_monotonic, -ts.tv_sec, -ts.tv_nsec); - write_sequnlock_irqrestore(&xtime_lock, flags); - /* Enable TOD clock interrupts on the boot cpu. */ init_cpu_timer(); |