diff options
| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2007-02-05 21:18:19 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2007-02-05 21:18:19 +0100 |
| commit | d54853ef8cb17296ac7bce9c77430fb7c80532d0 (patch) | |
| tree | 649e14d532e17231225a042a7c9a3d9207ad91ee /arch/s390/kernel/smp.c | |
| parent | c1821c2e9711adc3cd298a16b7237c92a2cee78d (diff) | |
[S390] ETR support.
This patch adds support for clock synchronization to an external time
reference (ETR). The external time reference sends an oscillator
signal and a synchronization signal every 2^20 microseconds to keep
the TOD clocks of all connected servers in sync. For availability
two ETR units can be connected to a machine. If the clock deviates
for more than the sync-check tolerance all cpus get a machine check
that indicates that the clock is out of sync. For the lovely details
how to get the clock back in sync see the code below.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/smp.c')
| -rw-r--r-- | arch/s390/kernel/smp.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index cb155d9fd74..08f9a4dfb18 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -457,9 +457,10 @@ int __devinit start_secondary(void *cpuvoid) /* Setup the cpu */ cpu_init(); preempt_disable(); - /* init per CPU timer */ + /* Enable TOD clock interrupts on the secondary cpu. */ init_cpu_timer(); #ifdef CONFIG_VIRT_TIMER + /* Enable cpu timer interrupts on the secondary cpu. */ init_cpu_vtimer(); #endif /* Enable pfault pseudo page faults on this cpu. */ |