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mutex: Avoid label warning when !CONFIG_MUTEX_SPIN_ON_OWNER
[platform/adaptation/renesas_rcar/renesas_kernel.git]
/
kernel
/
mutex.c
diff --git
a/kernel/mutex.c
b/kernel/mutex.c
index
e581ada
..
98164a5
100644
(file)
--- a/
kernel/mutex.c
+++ b/
kernel/mutex.c
@@
-18,6
+18,7
@@
* Also see Documentation/mutex-design.txt.
*/
#include <linux/mutex.h>
* Also see Documentation/mutex-design.txt.
*/
#include <linux/mutex.h>
+#include <linux/ww_mutex.h>
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/sched/rt.h>
#include <linux/export.h>
@@
-208,11
+209,13
@@
int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
*/
static inline int mutex_can_spin_on_owner(struct mutex *lock)
{
*/
static inline int mutex_can_spin_on_owner(struct mutex *lock)
{
+ struct task_struct *owner;
int retval = 1;
rcu_read_lock();
int retval = 1;
rcu_read_lock();
- if (lock->owner)
- retval = lock->owner->on_cpu;
+ owner = ACCESS_ONCE(lock->owner);
+ if (owner)
+ retval = owner->on_cpu;
rcu_read_unlock();
/*
* if lock->owner is not set, the mutex owner may have just acquired
rcu_read_unlock();
/*
* if lock->owner is not set, the mutex owner may have just acquired
@@
-460,7
+463,7
@@
__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* performed the optimistic spinning cannot be done.
*/
if (ACCESS_ONCE(ww->ctx))
* performed the optimistic spinning cannot be done.
*/
if (ACCESS_ONCE(ww->ctx))
-
break
;
+
goto slowpath
;
}
/*
}
/*
@@
-471,7
+474,7
@@
__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
owner = ACCESS_ONCE(lock->owner);
if (owner && !mutex_spin_on_owner(lock, owner)) {
mspin_unlock(MLOCK(lock), &node);
owner = ACCESS_ONCE(lock->owner);
if (owner && !mutex_spin_on_owner(lock, owner)) {
mspin_unlock(MLOCK(lock), &node);
-
break
;
+
goto slowpath
;
}
if ((atomic_read(&lock->count) == 1) &&
}
if ((atomic_read(&lock->count) == 1) &&
@@
-498,7
+501,7
@@
__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* the owner complete.
*/
if (!owner && (need_resched() || rt_task(task)))
* the owner complete.
*/
if (!owner && (need_resched() || rt_task(task)))
-
break
;
+
goto slowpath
;
/*
* The cpu_relax() call is a compiler barrier which forces
/*
* The cpu_relax() call is a compiler barrier which forces
@@
-512,6
+515,10
@@
slowpath:
#endif
spin_lock_mutex(&lock->wait_lock, flags);
#endif
spin_lock_mutex(&lock->wait_lock, flags);
+ /* once more, can we acquire the lock? */
+ if (MUTEX_SHOW_NO_WAITER(lock) && (atomic_xchg(&lock->count, 0) == 1))
+ goto skip_wait;
+
debug_mutex_lock_common(lock, &waiter);
debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
debug_mutex_lock_common(lock, &waiter);
debug_mutex_add_waiter(lock, &waiter, task_thread_info(task));
@@
-519,9
+526,6
@@
slowpath:
list_add_tail(&waiter.list, &lock->wait_list);
waiter.task = task;
list_add_tail(&waiter.list, &lock->wait_list);
waiter.task = task;
- if (MUTEX_SHOW_NO_WAITER(lock) && (atomic_xchg(&lock->count, -1) == 1))
- goto done;
-
lock_contended(&lock->dep_map, ip);
for (;;) {
lock_contended(&lock->dep_map, ip);
for (;;) {
@@
-535,7
+539,7
@@
slowpath:
* other waiters:
*/
if (MUTEX_SHOW_NO_WAITER(lock) &&
* other waiters:
*/
if (MUTEX_SHOW_NO_WAITER(lock) &&
- (atomic_xchg(&lock->count, -1) == 1))
+
(atomic_xchg(&lock->count, -1) == 1))
break;
/*
break;
/*
@@
-560,24
+564,25
@@
slowpath:
schedule_preempt_disabled();
spin_lock_mutex(&lock->wait_lock, flags);
}
schedule_preempt_disabled();
spin_lock_mutex(&lock->wait_lock, flags);
}
+ mutex_remove_waiter(lock, &waiter, current_thread_info());
+ /* set it to 0 if there are no waiters left: */
+ if (likely(list_empty(&lock->wait_list)))
+ atomic_set(&lock->count, 0);
+ debug_mutex_free_waiter(&waiter);
-done:
+skip_wait:
+ /* got the lock - cleanup and rejoice! */
lock_acquired(&lock->dep_map, ip);
lock_acquired(&lock->dep_map, ip);
- /* got the lock - rejoice! */
- mutex_remove_waiter(lock, &waiter, current_thread_info());
mutex_set_owner(lock);
if (!__builtin_constant_p(ww_ctx == NULL)) {
mutex_set_owner(lock);
if (!__builtin_constant_p(ww_ctx == NULL)) {
- struct ww_mutex *ww = container_of(lock,
- struct ww_mutex,
- base);
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
struct mutex_waiter *cur;
/*
* This branch gets optimized out for the common case,
* and is only important for ww_mutex_lock.
*/
struct mutex_waiter *cur;
/*
* This branch gets optimized out for the common case,
* and is only important for ww_mutex_lock.
*/
-
ww_mutex_lock_acquired(ww, ww_ctx);
ww->ctx = ww_ctx;
ww_mutex_lock_acquired(ww, ww_ctx);
ww->ctx = ww_ctx;
@@
-591,15
+596,8
@@
done:
}
}
}
}
- /* set it to 0 if there are no waiters left: */
- if (likely(list_empty(&lock->wait_list)))
- atomic_set(&lock->count, 0);
-
spin_unlock_mutex(&lock->wait_lock, flags);
spin_unlock_mutex(&lock->wait_lock, flags);
-
- debug_mutex_free_waiter(&waiter);
preempt_enable();
preempt_enable();
-
return 0;
err:
return 0;
err: