diff options
| author | Jason Low <[email protected]> | 2016-06-03 22:26:02 -0700 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2016-06-08 15:16:42 +0200 |
| commit | 8ee62b1870be8e630158701632a533d0378e15b8 (patch) | |
| tree | 18f68e695ee974f059703e75957e201695049cb9 /include/linux/rwsem.h | |
| parent | 055ce0fd1b86c204430cbc0887165599d6e15090 (diff) | |
locking/rwsem: Convert sem->count to 'atomic_long_t'
Convert the rwsem count variable to an atomic_long_t since we use it
as an atomic variable. This also allows us to remove the
rwsem_atomic_{add,update}() "abstraction" which would now be an unnecesary
level of indirection. In follow up patches, we also remove the
rwsem_atomic_{add,update}() definitions across the various architectures.
Suggested-by: Peter Zijlstra <[email protected]>
Signed-off-by: Jason Low <[email protected]>
[ Build warning fixes on various architectures. ]
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Jason Low <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Hurley <[email protected]>
Cc: Terry Rudd <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Waiman Long <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'include/linux/rwsem.h')
| -rw-r--r-- | include/linux/rwsem.h | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index d37fbb34d06f..dd1d14250340 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -23,10 +23,11 @@ struct rw_semaphore; #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK #include <linux/rwsem-spinlock.h> /* use a generic implementation */ +#define __RWSEM_INIT_COUNT(name) .count = RWSEM_UNLOCKED_VALUE #else /* All arch specific implementations share the same struct */ struct rw_semaphore { - long count; + atomic_long_t count; struct list_head wait_list; raw_spinlock_t wait_lock; #ifdef CONFIG_RWSEM_SPIN_ON_OWNER @@ -54,9 +55,10 @@ extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem); /* In all implementations count != 0 means locked */ static inline int rwsem_is_locked(struct rw_semaphore *sem) { - return sem->count != 0; + return atomic_long_read(&sem->count) != 0; } +#define __RWSEM_INIT_COUNT(name) .count = ATOMIC_LONG_INIT(RWSEM_UNLOCKED_VALUE) #endif /* Common initializer macros and functions */ @@ -74,7 +76,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) #endif #define __RWSEM_INITIALIZER(name) \ - { .count = RWSEM_UNLOCKED_VALUE, \ + { __RWSEM_INIT_COUNT(name), \ .wait_list = LIST_HEAD_INIT((name).wait_list), \ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock) \ __RWSEM_OPT_INIT(name) \ |