Messages in this thread Patch in this message |  | | From | Will Deacon <> | Subject | [PATCH 04/10] locking/qspinlock: Use atomic_cond_read_acquire | Date | Thu, 5 Apr 2018 17:59:01 +0100 |
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Rather than dig into the counter field of the atomic_t inside the qspinlock structure so that we can call smp_cond_load_acquire, use atomic_cond_read_acquire instead, which operates on the atomic_t directly.
Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com> --- kernel/locking/qspinlock.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index cdfa7b7328a8..291e1526d27b 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -331,8 +331,8 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) * barriers. */ if (val & _Q_LOCKED_MASK) - smp_cond_load_acquire(&lock->val.counter, - !(VAL & _Q_LOCKED_MASK)); + atomic_cond_read_acquire(&lock->val, + !(VAL & _Q_LOCKED_MASK)); /* * take ownership and clear the pending bit. * @@ -433,8 +433,8 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) * * The PV pv_wait_head_or_lock function, if active, will acquire * the lock and return a non-zero value. So we have to skip the - * smp_cond_load_acquire() call. As the next PV queue head hasn't been - * designated yet, there is no way for the locked value to become + * atomic_cond_read_acquire() call. As the next PV queue head hasn't + * been designated yet, there is no way for the locked value to become * _Q_SLOW_VAL. So both the set_locked() and the * atomic_cmpxchg_relaxed() calls will be safe. * @@ -444,7 +444,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) if ((val = pv_wait_head_or_lock(lock, node))) goto locked; - val = smp_cond_load_acquire(&lock->val.counter, !(VAL & _Q_LOCKED_PENDING_MASK)); + val = atomic_cond_read_acquire(&lock->val, !(VAL & _Q_LOCKED_PENDING_MASK)); locked: /* @@ -461,7 +461,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) /* In the PV case we might already have _Q_LOCKED_VAL set */ if ((val & _Q_TAIL_MASK) == tail) { /* - * The smp_cond_load_acquire() call above has provided the + * The atomic_cond_read_acquire() call above has provided the * necessary acquire semantics required for locking. */ old = atomic_cmpxchg_relaxed(&lock->val, val, _Q_LOCKED_VAL); -- 2.1.4
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