Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 91e4202..a8a0803 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -252,7 +252,6 @@
 	if (dl_entity_is_special(dl_se))
 		return;
 
-	WARN_ON(hrtimer_active(&dl_se->inactive_timer));
 	WARN_ON(dl_se->dl_non_contending);
 
 	zerolag_time = dl_se->deadline -
@@ -269,7 +268,7 @@
 	 * If the "0-lag time" already passed, decrease the active
 	 * utilization now, instead of starting a timer
 	 */
-	if (zerolag_time < 0) {
+	if ((zerolag_time < 0) || hrtimer_active(&dl_se->inactive_timer)) {
 		if (dl_task(p))
 			sub_running_bw(dl_se, dl_rq);
 		if (!dl_task(p) || p->state == TASK_DEAD) {
@@ -288,7 +287,7 @@
 
 	dl_se->dl_non_contending = 1;
 	get_task_struct(p);
-	hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL);
+	hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL_HARD);
 }
 
 static void task_contending(struct sched_dl_entity *dl_se, int flags)
@@ -530,6 +529,7 @@
 static struct rq *dl_task_offline_migration(struct rq *rq, struct task_struct *p)
 {
 	struct rq *later_rq = NULL;
+	struct dl_bw *dl_b;
 
 	later_rq = find_lock_later_rq(p, rq);
 	if (!later_rq) {
@@ -539,7 +539,7 @@
 		 * If we cannot preempt any rq, fall back to pick any
 		 * online CPU:
 		 */
-		cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
+		cpu = cpumask_any_and(cpu_active_mask, p->cpus_ptr);
 		if (cpu >= nr_cpu_ids) {
 			/*
 			 * Failed to find any suitable CPU.
@@ -558,6 +558,38 @@
 		double_lock_balance(rq, later_rq);
 	}
 
+	if (p->dl.dl_non_contending || p->dl.dl_throttled) {
+		/*
+		 * Inactive timer is armed (or callback is running, but
+		 * waiting for us to release rq locks). In any case, when it
+		 * will fire (or continue), it will see running_bw of this
+		 * task migrated to later_rq (and correctly handle it).
+		 */
+		sub_running_bw(&p->dl, &rq->dl);
+		sub_rq_bw(&p->dl, &rq->dl);
+
+		add_rq_bw(&p->dl, &later_rq->dl);
+		add_running_bw(&p->dl, &later_rq->dl);
+	} else {
+		sub_rq_bw(&p->dl, &rq->dl);
+		add_rq_bw(&p->dl, &later_rq->dl);
+	}
+
+	/*
+	 * And we finally need to fixup root_domain(s) bandwidth accounting,
+	 * since p is still hanging out in the old (now moved to default) root
+	 * domain.
+	 */
+	dl_b = &rq->rd->dl_bw;
+	raw_spin_lock(&dl_b->lock);
+	__dl_sub(dl_b, p->dl.dl_bw, cpumask_weight(rq->rd->span));
+	raw_spin_unlock(&dl_b->lock);
+
+	dl_b = &later_rq->rd->dl_bw;
+	raw_spin_lock(&dl_b->lock);
+	__dl_add(dl_b, p->dl.dl_bw, cpumask_weight(later_rq->rd->span));
+	raw_spin_unlock(&dl_b->lock);
+
 	set_task_cpu(p, later_rq->cpu);
 	double_unlock_balance(later_rq, rq);
 
@@ -727,7 +759,7 @@
  * refill the runtime and set the deadline a period in the future,
  * because keeping the current (absolute) deadline of the task would
  * result in breaking guarantees promised to other tasks (refer to
- * Documentation/scheduler/sched-deadline.txt for more informations).
+ * Documentation/scheduler/sched-deadline.rst for more information).
  *
  * This function returns true if:
  *
@@ -924,7 +956,7 @@
 	 */
 	if (!hrtimer_is_queued(timer)) {
 		get_task_struct(p);
-		hrtimer_start(timer, act, HRTIMER_MODE_ABS);
+		hrtimer_start(timer, act, HRTIMER_MODE_ABS_HARD);
 	}
 
 	return 1;
@@ -1054,7 +1086,7 @@
 {
 	struct hrtimer *timer = &dl_se->dl_timer;
 
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	timer->function = dl_task_timer;
 }
 
@@ -1196,7 +1228,7 @@
 						 &curr->dl);
 	} else {
 		unsigned long scale_freq = arch_scale_freq_capacity(cpu);
-		unsigned long scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
+		unsigned long scale_cpu = arch_scale_cpu_capacity(cpu);
 
 		scaled_delta_exec = cap_scale(delta_exec, scale_freq);
 		scaled_delta_exec = cap_scale(scaled_delta_exec, scale_cpu);
@@ -1293,7 +1325,7 @@
 {
 	struct hrtimer *timer = &dl_se->inactive_timer;
 
-	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	timer->function = inactive_task_timer;
 }
 
@@ -1659,6 +1691,22 @@
 	resched_curr(rq);
 }
 
+static int balance_dl(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
+{
+	if (!on_dl_rq(&p->dl) && need_pull_dl_task(rq, p)) {
+		/*
+		 * This is OK, because current is on_cpu, which avoids it being
+		 * picked for load-balance and preemption/IRQs are still
+		 * disabled avoiding further scheduler activity on it and we've
+		 * not yet started the picking loop.
+		 */
+		rq_unpin_lock(rq, rf);
+		pull_dl_task(rq);
+		rq_repin_lock(rq, rf);
+	}
+
+	return sched_stop_runnable(rq) || sched_dl_runnable(rq);
+}
 #endif /* CONFIG_SMP */
 
 /*
@@ -1695,6 +1743,22 @@
 }
 #endif
 
+static void set_next_task_dl(struct rq *rq, struct task_struct *p)
+{
+	p->se.exec_start = rq_clock_task(rq);
+
+	/* You can't push away the running task */
+	dequeue_pushable_dl_task(rq, p);
+
+	if (hrtick_enabled(rq))
+		start_hrtick_dl(rq, p);
+
+	if (rq->curr->sched_class != &dl_sched_class)
+		update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 0);
+
+	deadline_queue_push_tasks(rq);
+}
+
 static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq,
 						   struct dl_rq *dl_rq)
 {
@@ -1710,59 +1774,18 @@
 pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 {
 	struct sched_dl_entity *dl_se;
+	struct dl_rq *dl_rq = &rq->dl;
 	struct task_struct *p;
-	struct dl_rq *dl_rq;
 
-	dl_rq = &rq->dl;
+	WARN_ON_ONCE(prev || rf);
 
-	if (need_pull_dl_task(rq, prev)) {
-		/*
-		 * This is OK, because current is on_cpu, which avoids it being
-		 * picked for load-balance and preemption/IRQs are still
-		 * disabled avoiding further scheduler activity on it and we're
-		 * being very careful to re-start the picking loop.
-		 */
-		rq_unpin_lock(rq, rf);
-		pull_dl_task(rq);
-		rq_repin_lock(rq, rf);
-		/*
-		 * pull_dl_task() can drop (and re-acquire) rq->lock; this
-		 * means a stop task can slip in, in which case we need to
-		 * re-start task selection.
-		 */
-		if (rq->stop && task_on_rq_queued(rq->stop))
-			return RETRY_TASK;
-	}
-
-	/*
-	 * When prev is DL, we may throttle it in put_prev_task().
-	 * So, we update time before we check for dl_nr_running.
-	 */
-	if (prev->sched_class == &dl_sched_class)
-		update_curr_dl(rq);
-
-	if (unlikely(!dl_rq->dl_nr_running))
+	if (!sched_dl_runnable(rq))
 		return NULL;
 
-	put_prev_task(rq, prev);
-
 	dl_se = pick_next_dl_entity(rq, dl_rq);
 	BUG_ON(!dl_se);
-
 	p = dl_task_of(dl_se);
-	p->se.exec_start = rq_clock_task(rq);
-
-	/* Running task will never be pushed. */
-       dequeue_pushable_dl_task(rq, p);
-
-	if (hrtick_enabled(rq))
-		start_hrtick_dl(rq, p);
-
-	deadline_queue_push_tasks(rq);
-
-	if (rq->curr->sched_class != &dl_sched_class)
-		update_dl_rq_load_avg(rq_clock_task(rq), rq, 0);
-
+	set_next_task_dl(rq, p);
 	return p;
 }
 
@@ -1770,7 +1793,7 @@
 {
 	update_curr_dl(rq);
 
-	update_dl_rq_load_avg(rq_clock_task(rq), rq, 1);
+	update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 1);
 	if (on_dl_rq(&p->dl) && p->nr_cpus_allowed > 1)
 		enqueue_pushable_dl_task(rq, p);
 }
@@ -1787,7 +1810,7 @@
 {
 	update_curr_dl(rq);
 
-	update_dl_rq_load_avg(rq_clock_task(rq), rq, 1);
+	update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 1);
 	/*
 	 * Even when we have runtime, update_curr_dl() might have resulted in us
 	 * not being the leftmost task anymore. In that case NEED_RESCHED will
@@ -1806,16 +1829,6 @@
 	 */
 }
 
-static void set_curr_task_dl(struct rq *rq)
-{
-	struct task_struct *p = rq->curr;
-
-	p->se.exec_start = rq_clock_task(rq);
-
-	/* You can't push away the running task */
-	dequeue_pushable_dl_task(rq, p);
-}
-
 #ifdef CONFIG_SMP
 
 /* Only try algorithms three times */
@@ -1824,7 +1837,7 @@
 static int pick_dl_task(struct rq *rq, struct task_struct *p, int cpu)
 {
 	if (!task_running(rq, p) &&
-	    cpumask_test_cpu(cpu, &p->cpus_allowed))
+	    cpumask_test_cpu(cpu, p->cpus_ptr))
 		return 1;
 	return 0;
 }
@@ -1974,7 +1987,7 @@
 		/* Retry if something changed. */
 		if (double_lock_balance(rq, later_rq)) {
 			if (unlikely(task_rq(task) != rq ||
-				     !cpumask_test_cpu(later_rq->cpu, &task->cpus_allowed) ||
+				     !cpumask_test_cpu(later_rq->cpu, task->cpus_ptr) ||
 				     task_running(rq, task) ||
 				     !dl_task(task) ||
 				     !task_on_rq_queued(task))) {
@@ -2041,10 +2054,8 @@
 		return 0;
 
 retry:
-	if (unlikely(next_task == rq->curr)) {
-		WARN_ON(1);
+	if (WARN_ON(next_task == rq->curr))
 		return 0;
-	}
 
 	/*
 	 * If next_task preempts rq->curr, and rq->curr
@@ -2090,17 +2101,13 @@
 	}
 
 	deactivate_task(rq, next_task, 0);
-	sub_running_bw(&next_task->dl, &rq->dl);
-	sub_rq_bw(&next_task->dl, &rq->dl);
 	set_task_cpu(next_task, later_rq->cpu);
-	add_rq_bw(&next_task->dl, &later_rq->dl);
 
 	/*
 	 * Update the later_rq clock here, because the clock is used
 	 * by the cpufreq_update_util() inside __add_running_bw().
 	 */
 	update_rq_clock(later_rq);
-	add_running_bw(&next_task->dl, &later_rq->dl);
 	activate_task(later_rq, next_task, ENQUEUE_NOCLOCK);
 	ret = 1;
 
@@ -2188,11 +2195,7 @@
 			resched = true;
 
 			deactivate_task(src_rq, p, 0);
-			sub_running_bw(&p->dl, &src_rq->dl);
-			sub_rq_bw(&p->dl, &src_rq->dl);
 			set_task_cpu(p, this_cpu);
-			add_rq_bw(&p->dl, &this_rq->dl);
-			add_running_bw(&p->dl, &this_rq->dl);
 			activate_task(this_rq, p, 0);
 			dmin = p->dl.deadline;
 
@@ -2285,6 +2288,36 @@
 					GFP_KERNEL, cpu_to_node(i));
 }
 
+void dl_add_task_root_domain(struct task_struct *p)
+{
+	struct rq_flags rf;
+	struct rq *rq;
+	struct dl_bw *dl_b;
+
+	rq = task_rq_lock(p, &rf);
+	if (!dl_task(p))
+		goto unlock;
+
+	dl_b = &rq->rd->dl_bw;
+	raw_spin_lock(&dl_b->lock);
+
+	__dl_add(dl_b, p->dl.dl_bw, cpumask_weight(rq->rd->span));
+
+	raw_spin_unlock(&dl_b->lock);
+
+unlock:
+	task_rq_unlock(rq, p, &rf);
+}
+
+void dl_clear_root_domain(struct root_domain *rd)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&rd->dl_bw.lock, flags);
+	rd->dl_bw.total_bw = 0;
+	raw_spin_unlock_irqrestore(&rd->dl_bw.lock, flags);
+}
+
 #endif /* CONFIG_SMP */
 
 static void switched_from_dl(struct rq *rq, struct task_struct *p)
@@ -2405,8 +2438,10 @@
 
 	.pick_next_task		= pick_next_task_dl,
 	.put_prev_task		= put_prev_task_dl,
+	.set_next_task		= set_next_task_dl,
 
 #ifdef CONFIG_SMP
+	.balance		= balance_dl,
 	.select_task_rq		= select_task_rq_dl,
 	.migrate_task_rq	= migrate_task_rq_dl,
 	.set_cpus_allowed       = set_cpus_allowed_dl,
@@ -2415,7 +2450,6 @@
 	.task_woken		= task_woken_dl,
 #endif
 
-	.set_curr_task		= set_curr_task_dl,
 	.task_tick		= task_tick_dl,
 	.task_fork              = task_fork_dl,