[05/11] ia64, rwsem: provide __down_write_killable

Commit Message

Michal Hocko April 1, 2016, 11:04 a.m. UTC

From: Michal Hocko <[e-mail]>

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 <[e-mail]>
---
 arch/ia64/include/asm/rwsem.h | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

Patch

diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h
index 3027e7516d85..5e78cb40d9df 100644
--- a/arch/ia64/include/asm/rwsem.h
+++ b/arch/ia64/include/asm/rwsem.h
@@ -49,8 +49,8 @@  __down_read (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)
 {
 	long old, new;
 
@@ -59,10 +59,26 @@  __down_write (struct rw_semaphore *sem)
 		new = old + RWSEM_ACTIVE_WRITE_BIAS;
 	} while (cmpxchg_acq(&sem->count, old, new) != old);
 
-	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;
+}
+
 /*
  * unlock after reading
  */