[S390] nohz/sclp: disable timer on synchronous waits.
sclp_sync_wait wait synchronously for an sclp interrupt and disables
timer interrupts. However on the irq enter paths there is an extra
check if a timer interrupt would be due and calls the timer callback.
This would schedule softirqs in the wrong context.
So introduce local_tick_enable/disable which prevents this.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 3c8b25e..1fd8f21 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -399,6 +399,7 @@
void
sclp_sync_wait(void)
{
+ unsigned long long old_tick;
unsigned long flags;
unsigned long cr0, cr0_sync;
u64 timeout;
@@ -419,11 +420,12 @@
if (!irq_context)
local_bh_disable();
/* Enable service-signal interruption, disable timer interrupts */
+ old_tick = local_tick_disable();
trace_hardirqs_on();
__ctl_store(cr0, 0, 0);
cr0_sync = cr0;
+ cr0_sync &= 0xffff00a0;
cr0_sync |= 0x00000200;
- cr0_sync &= 0xFFFFF3AC;
__ctl_load(cr0_sync, 0, 0);
__raw_local_irq_stosm(0x01);
/* Loop until driver state indicates finished request */
@@ -439,9 +441,9 @@
__ctl_load(cr0, 0, 0);
if (!irq_context)
_local_bh_enable();
+ local_tick_enable(old_tick);
local_irq_restore(flags);
}
-
EXPORT_SYMBOL(sclp_sync_wait);
/* Dispatch changes in send and receive mask to registered listeners. */