[PATCH REBASED 1/6] alpha: Add __down_read_killable()

Kirill Tkhai
2017-09-29T16:05:56Z

Similar to __down_write_killable(), and read killable primitive.

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

diff --git a/arch/alpha/include/asm/rwsem.h b/arch/alpha/include/asm/rwsem.h
index 77873d0ad293..7118bd090085 100644
--- a/arch/alpha/include/asm/rwsem.h
+++ b/arch/alpha/include/asm/rwsem.h
@@ -21,7 +21,7 @@
#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)

-static inline void __down_read(struct rw_semaphore *sem)
+static inline int ___down_read(struct rw_semaphore *sem)
{
long oldcount;
#ifndef CONFIG_SMP
@@ -41,10 +41,24 @@ static inline void __down_read(struct rw_semaphore *sem)
:"=&r" (oldcount), "=m" (sem->count), "=&r" (temp)
:"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory");
#endif
- if (unlikely(oldcount < 0))
+ return (oldcount < 0);
+}
+
+static inline void __down_read(struct rw_semaphore *sem)
+{
+ if (unlikely(___down_read(sem)))
rwsem_down_read_failed(sem);
}

+static inline int __down_read_killable(struct rw_semaphore *sem)
+{
+ if (unlikely(___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
*/