From f9c811fac48cfbbfb452b08d1042386947868d07 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Thu, 26 Apr 2018 11:34:21 +0100
Subject: [PATCH 07/12] locking/qspinlock: Use atomic_cond_read_acquire()
Git-commit: f9c811fac48cfbbfb452b08d1042386947868d07
Patch-mainline: v4.18-rc1
References: bsc#1050549
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.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boqun.feng@gmail.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1524738868-31318-8-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
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 b51494a50b1e..56af1fa9874d 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -337,8 +337,8 @@ 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));
}
/*
@@ -441,8 +441,8 @@ 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.
*
@@ -452,7 +452,7 @@ 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:
/*
@@ -469,7 +469,7 @@ 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);
--
2.16.4