summaryrefslogtreecommitdiff
path: root/include/linux/rwsem.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/rwsem.h')
-rw-r--r--include/linux/rwsem.h34
1 files changed, 16 insertions, 18 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 8d79708146aa..035d3c57fc8a 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -13,10 +13,11 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/spinlock.h>
-
#include <linux/atomic.h>
+#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
+#include <linux/osq_lock.h>
+#endif
-struct optimistic_spin_queue;
struct rw_semaphore;
#ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
@@ -25,15 +26,15 @@ struct rw_semaphore;
/* All arch specific implementations share the same struct */
struct rw_semaphore {
long count;
- raw_spinlock_t wait_lock;
struct list_head wait_list;
-#ifdef CONFIG_SMP
+ raw_spinlock_t wait_lock;
+#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
+ struct optimistic_spin_queue osq; /* spinner MCS lock */
/*
* Write owner. Used as a speculative check to see
* if the owner is running on the cpu.
*/
struct task_struct *owner;
- struct optimistic_spin_queue *osq; /* spinner MCS lock */
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
@@ -64,22 +65,19 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
-#if defined(CONFIG_SMP) && !defined(CONFIG_RWSEM_GENERIC_SPINLOCK)
-#define __RWSEM_INITIALIZER(name) \
- { RWSEM_UNLOCKED_VALUE, \
- __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
- LIST_HEAD_INIT((name).wait_list), \
- NULL, /* owner */ \
- NULL /* mcs lock */ \
- __RWSEM_DEP_MAP_INIT(name) }
+#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
+#define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL
#else
-#define __RWSEM_INITIALIZER(name) \
- { RWSEM_UNLOCKED_VALUE, \
- __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
- LIST_HEAD_INIT((name).wait_list) \
- __RWSEM_DEP_MAP_INIT(name) }
+#define __RWSEM_OPT_INIT(lockname)
#endif
+#define __RWSEM_INITIALIZER(name) \
+ { .count = RWSEM_UNLOCKED_VALUE, \
+ .wait_list = LIST_HEAD_INIT((name).wait_list), \
+ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock) \
+ __RWSEM_OPT_INIT(name) \
+ __RWSEM_DEP_MAP_INIT(name) }
+
#define DECLARE_RWSEM(name) \
struct rw_semaphore name = __RWSEM_INITIALIZER(name)