[PATCH REBASED 3/6] s390: Add __down_read_killable()

[Kirill Tkhai]

Similar to __down_write_killable(), and read killable primitive.

Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
---
 arch/s390/include/asm/rwsem.h |   18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h
index 597e7e96b59e..6bef7d5fbf1c 100644
--- a/arch/s390/include/asm/rwsem.h
+++ b/arch/s390/include/asm/rwsem.h
@@ -49,7 +49,7 @@
 /*
  * lock for reading
  */
-static inline void __down_read(struct rw_semaphore *sem)
+static inline int ___down_read(struct rw_semaphore *sem)
 {
        signed long old, new;
 
@@ -62,10 +62,24 @@ static inline void __down_read(struct rw_semaphore *sem)
                : "=&d" (old), "=&d" (new), "=Q" (sem->count)
                : "Q" (sem->count), "i" (RWSEM_ACTIVE_READ_BIAS)
                : "cc", "memory");
-       if (old < 0)
+       return (old < 0);
+}
+
+static inline void __down_read(struct rw_semaphore *sem)
+{
+       if (___down_read(sem))
                rwsem_down_read_failed(sem);
 }
 
+static inline int __down_read_killable(struct rw_semaphore *sem)
+{
+       if (___down_read(sem))
+               if (IS_ERR(rwsem_down_read_failed_killable(sem)))
+                       return -EINTR;
+
+       return 0;
+}
+
 /*
  * trylock for reading -- returns 1 if successful, 0 if contention
  */