[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>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/asm-s390/hardirq.h b/include/asm-s390/hardirq.h
index 4b7cb964ff35..89ec7056da28 100644
--- a/include/asm-s390/hardirq.h
+++ b/include/asm-s390/hardirq.h
@@ -34,4 +34,18 @@ typedef struct {
 
 void clock_comparator_work(void);
 
+static inline unsigned long long local_tick_disable(void)
+{
+        unsigned long long old;
+
+        old = S390_lowcore.clock_comparator;
+        S390_lowcore.clock_comparator = -1ULL;
+        return old;
+}
+
+static inline void local_tick_enable(unsigned long long comp)
+{
+        S390_lowcore.clock_comparator = comp;
+}
+
 #endif /* __ASM_HARDIRQ_H */