[PATCH 06/11] s390, rwsem: provide __down_write_killable

[Michal Hocko]

From: Michal Hocko <mho...@suse.com>

Introduce ___down_write for the fast path and reuse it for __down_write
resp. __down_write_killable each using the respective generic slow path
(rwsem_down_write_failed resp. rwsem_down_write_failed_killable).

Signed-off-by: Michal Hocko <mho...@suse.com>
---
 arch/s390/include/asm/rwsem.h | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h
index 8e52e72f3efc..8e7b2b7e10f3 100644
--- a/arch/s390/include/asm/rwsem.h
+++ b/arch/s390/include/asm/rwsem.h
@@ -90,7 +90,7 @@ static inline int __down_read_trylock(struct rw_semaphore 
*sem)
 /*
  * lock for writing
  */
-static inline void __down_write(struct rw_semaphore *sem)
+static inline long ___down_write(struct rw_semaphore *sem)
 {
        signed long old, new, tmp;
 
@@ -104,10 +104,25 @@ static inline void __down_write(struct rw_semaphore *sem)
                : "=&d" (old), "=&d" (new), "=Q" (sem->count)
                : "Q" (sem->count), "m" (tmp)
                : "cc", "memory");
-       if (old != 0)
+
+       return old;
+}
+
+static inline void __down_write(struct rw_semaphore *sem)
+{
+       if (___down_write(sem))
                rwsem_down_write_failed(sem);
 }
 
+static inline int __down_write_killable(struct rw_semaphore *sem)
+{
+       if (___down_write(sem))
+               if (IS_ERR(rwsem_down_write_failed_killable(sem)))
+                       return -EINTR;
+
+       return 0;
+}
+
 /*
  * trylock for writing -- returns 1 if successful, 0 if contention
  */
-- 
2.7.0