s390/rwlock: use directed yield for write-locked rwlocks

Add an owner field to the arch_rwlock_t to be able to pass the timeslice
of a virtual CPU with diagnose 0x9c to the lock owner in case the rwlock
is write-locked. The undirected yield in case the rwlock is acquired
writable but the lock is read-locked is removed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 243c7e512600..abec97b4ddbf 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -333,12 +333,6 @@ int smp_vcpu_scheduled(int cpu)
         return pcpu_running(pcpu_devices + cpu);
 }
 
-void smp_yield(void)
-{
-        if (MACHINE_HAS_DIAG44)
-                asm volatile("diag 0,0,0x44");
-}
-
 void smp_yield_cpu(int cpu)
 {
         if (MACHINE_HAS_DIAG9C)