s390/time: return with irqs disabled from psw_idle
Modify the psw_idle waiting logic in entry[64].S to return with
interrupts disabled. This avoids potential issues with udelay
and interrupt loops as interrupts are not reenabled after
clock comparator interrupts.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 980c7aa..2b2188b 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -929,7 +929,7 @@
stg %r9,__LC_SYSTEM_TIMER
mvc __LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)
# prepare return psw
- nihh %r8,0xfffd # clear wait state bit
+ nihh %r8,0xfcfd # clear irq & wait state bits
lg %r9,48(%r11) # return from psw_idle
br %r14
cleanup_idle_insn: