From: "Dr. David Alan Gilbert" <linux@xxxxxxxxxxx>
ldsem_down_write_trylock() was added in 2013 by
commit 4898e640caf0 ("tty: Add timed, writer-prioritized rw semaphore")
but hasn't been used.
Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@xxxxxxxxxxx>
---
drivers/tty/tty_ldsem.c | 17 -----------------
include/linux/tty_ldisc.h | 1 -
2 files changed, 18 deletions(-)
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c
index 3be428c16260..4e18031a5ca3 100644
--- a/drivers/tty/tty_ldsem.c
+++ b/drivers/tty/tty_ldsem.c
@@ -366,23 +366,6 @@ int __sched ldsem_down_write(struct ld_semaphore *sem, long timeout)
return __ldsem_down_write_nested(sem, 0, timeout);
}
-/*
- * trylock for writing -- returns 1 if successful, 0 if contention
- */
-int ldsem_down_write_trylock(struct ld_semaphore *sem)
-{
- long count = atomic_long_read(&sem->count);
-
- while ((count & LDSEM_ACTIVE_MASK) == 0) {
- if (atomic_long_try_cmpxchg(&sem->count, &count, count + LDSEM_WRITE_BIAS)) {
- rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_);
- lock_acquired(&sem->dep_map, _RET_IP_);
- return 1;
- }
- }
- return 0;
-}
-
/*
* release a read lock
*/
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index af01e89074b2..c5cccc3fc1e8 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -39,7 +39,6 @@ do { \
int ldsem_down_read(struct ld_semaphore *sem, long timeout);
int ldsem_down_read_trylock(struct ld_semaphore *sem);
int ldsem_down_write(struct ld_semaphore *sem, long timeout);
-int ldsem_down_write_trylock(struct ld_semaphore *sem);
void ldsem_up_read(struct ld_semaphore *sem);
void ldsem_up_write(struct ld_semaphore *sem);
--
2.48.1
