[PATCH v4 07/17] locking: Switch to _irq_{disable,enable}() variants in cleanup guards

[Boqun Feng <boqun@kernel.org>]

The semantics of various IRQ disabling guards match what
*_irq_{disable,enable}() provide, i.e. the interrupt disabling is
properly nested, therefore it's OK to switch to use
*_irq_{disable,enable}() primitives.

[boqun: Adjust the user-side changes in do_sched_cfs_*_timer() provided
by Peter and Lyude]

Signed-off-by: Boqun Feng <boqun@kernel.org>
---
 include/linux/spinlock.h | 26 ++++++++++++--------------
 kernel/sched/fair.c      | 12 ++++++------
 2 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 3d405cc4c121..799a8f7d2741 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -572,12 +572,12 @@ DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_nested, __acquires(_T), __releases(*(raw
 #define class_raw_spinlock_nested_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_nested, _T)
 
 DEFINE_LOCK_GUARD_1(raw_spinlock_irq, raw_spinlock_t,
-		    raw_spin_lock_irq(_T->lock),
-		    raw_spin_unlock_irq(_T->lock))
+		    raw_spin_lock_irq_disable(_T->lock),
+		    raw_spin_unlock_irq_enable(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_irq, __acquires(_T), __releases(*(raw_spinlock_t **)_T))
 #define class_raw_spinlock_irq_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_irq, _T)
 
-DEFINE_LOCK_GUARD_1_COND(raw_spinlock_irq, _try, raw_spin_trylock_irq(_T->lock))
+DEFINE_LOCK_GUARD_1_COND(raw_spinlock_irq, _try, raw_spin_trylock_irq_disable(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_irq_try, __acquires(_T), __releases(*(raw_spinlock_t **)_T))
 #define class_raw_spinlock_irq_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_irq_try, _T)
 
@@ -592,14 +592,13 @@ DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_bh_try, __acquires(_T), __releases(*(raw
 #define class_raw_spinlock_bh_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_bh_try, _T)
 
 DEFINE_LOCK_GUARD_1(raw_spinlock_irqsave, raw_spinlock_t,
-		    raw_spin_lock_irqsave(_T->lock, _T->flags),
-		    raw_spin_unlock_irqrestore(_T->lock, _T->flags),
-		    unsigned long flags)
+		    raw_spin_lock_irq_disable(_T->lock),
+		    raw_spin_unlock_irq_enable(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_irqsave, __acquires(_T), __releases(*(raw_spinlock_t **)_T))
 #define class_raw_spinlock_irqsave_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_irqsave, _T)
 
 DEFINE_LOCK_GUARD_1_COND(raw_spinlock_irqsave, _try,
-			 raw_spin_trylock_irqsave(_T->lock, _T->flags))
+			 raw_spin_trylock_irq_disable(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(raw_spinlock_irqsave_try, __acquires(_T), __releases(*(raw_spinlock_t **)_T))
 #define class_raw_spinlock_irqsave_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(raw_spinlock_irqsave_try, _T)
 
@@ -618,13 +617,13 @@ DECLARE_LOCK_GUARD_1_ATTRS(spinlock_try, __acquires(_T), __releases(*(spinlock_t
 #define class_spinlock_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_try, _T)
 
 DEFINE_LOCK_GUARD_1(spinlock_irq, spinlock_t,
-		    spin_lock_irq(_T->lock),
-		    spin_unlock_irq(_T->lock))
+		    spin_lock_irq_disable(_T->lock),
+		    spin_unlock_irq_enable(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(spinlock_irq, __acquires(_T), __releases(*(spinlock_t **)_T))
 #define class_spinlock_irq_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_irq, _T)
 
 DEFINE_LOCK_GUARD_1_COND(spinlock_irq, _try,
-			 spin_trylock_irq(_T->lock))
+			 spin_trylock_irq_disable(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(spinlock_irq_try, __acquires(_T), __releases(*(spinlock_t **)_T))
 #define class_spinlock_irq_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_irq_try, _T)
 
@@ -640,14 +639,13 @@ DECLARE_LOCK_GUARD_1_ATTRS(spinlock_bh_try, __acquires(_T), __releases(*(spinloc
 #define class_spinlock_bh_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_bh_try, _T)
 
 DEFINE_LOCK_GUARD_1(spinlock_irqsave, spinlock_t,
-		    spin_lock_irqsave(_T->lock, _T->flags),
-		    spin_unlock_irqrestore(_T->lock, _T->flags),
-		    unsigned long flags)
+		    spin_lock_irq_disable(_T->lock),
+		    spin_unlock_irq_enable(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(spinlock_irqsave, __acquires(_T), __releases(*(spinlock_t **)_T))
 #define class_spinlock_irqsave_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_irqsave, _T)
 
 DEFINE_LOCK_GUARD_1_COND(spinlock_irqsave, _try,
-			 spin_trylock_irqsave(_T->lock, _T->flags))
+			 spin_trylock_irq_disable(_T->lock))
 DECLARE_LOCK_GUARD_1_ATTRS(spinlock_irqsave_try, __acquires(_T), __releases(*(spinlock_t **)_T))
 #define class_spinlock_irqsave_try_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(spinlock_irqsave_try, _T)
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d78467ec6ee1..a46c4ff49f74 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7120,7 +7120,7 @@ static bool distribute_cfs_runtime(struct cfs_bandwidth *cfs_b)
  * period the timer is deactivated until scheduling resumes; cfs_b->idle is
  * used to track this state.
  */
-static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, unsigned long flags)
+static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
 	__must_hold(&cfs_b->lock)
 {
 	int throttled;
@@ -7155,10 +7155,10 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, u
 	 * This check is repeated as we release cfs_b->lock while we unthrottle.
 	 */
 	while (throttled && cfs_b->runtime > 0) {
-		raw_spin_unlock_irqrestore(&cfs_b->lock, flags);
+		raw_spin_unlock_irq_enable(&cfs_b->lock);
 		/* we can't nest cfs_b->lock while distributing bandwidth */
 		throttled = distribute_cfs_runtime(cfs_b);
-		raw_spin_lock_irqsave(&cfs_b->lock, flags);
+		raw_spin_lock_irq_disable(&cfs_b->lock);
 	}
 
 	/*
@@ -7266,7 +7266,7 @@ static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
 static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
 {
 	/* confirm we're still not at a refresh boundary */
-	scoped_guard(raw_spinlock_irqsave, &cfs_b->lock) {
+	scoped_guard(raw_spinlock_irq, &cfs_b->lock) {
 		u64 runtime = 0, slice = sched_cfs_bandwidth_slice();
 
 		cfs_b->slack_started = false;
@@ -7351,14 +7351,14 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
 	int idle = 0;
 	int count = 0;
 
-	CLASS(raw_spinlock_irqsave, cfsb_guard)(&cfs_b->lock);
+	guard(raw_spinlock_irq)(&cfs_b->lock);
 
 	for (;;) {
 		overrun = hrtimer_forward_now(timer, cfs_b->period);
 		if (!overrun)
 			break;
 
-		idle = do_sched_cfs_period_timer(cfs_b, overrun, cfsb_guard.flags);
+		idle = do_sched_cfs_period_timer(cfs_b, overrun);
 
 		if (++count > 3) {
 			u64 new, old = ktime_to_ns(cfs_b->period);
-- 
2.50.1 (Apple Git-155)