[PATCH 08/11] sparc, rwsem: provide __down_write_killable

Michal Hocko
2016-02-29T12:58:22Z

From: Michal Hocko <mhocko@suse.com>

which uses the same fast path as __down_write except it falls back to
rwsem_down_write_failed_killable slow path and return -EINTR if killed.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
arch/sparc/include/asm/rwsem.h | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/arch/sparc/include/asm/rwsem.h b/arch/sparc/include/asm/rwsem.h
index e5a0d575bc7f..c1e9e32e8b63 100644
--- a/arch/sparc/include/asm/rwsem.h
+++ b/arch/sparc/include/asm/rwsem.h
@@ -55,6 +55,19 @@ static inline void __down_write(struct rw_semaphore *sem)
rwsem_down_write_failed(sem);
}

+static inline int __down_write_killable(struct rw_semaphore *sem)
+{
+ long tmp;
+
+ tmp = atomic64_add_return(RWSEM_ACTIVE_WRITE_BIAS,
+ (atomic64_t *)(&sem->count));
+ if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS))
+ if (IS_ERR(rwsem_down_write_failed_killable(sem)))
+ return -EINTR;
+
+ return 0;
+}
+
static inline int __down_write_trylock(struct rw_semaphore *sem)
{
long tmp;
--
2.7.0