Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 5b33e2f..9558517 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1,6 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
- *  linux/kernel/time/tick-sched.c
- *
  *  Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
  *  Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
  *  Copyright(C) 2006-2007  Timesys Corp., Thomas Gleixner
@@ -8,8 +7,6 @@
  *  No idle tick implementation for low and high resolution timers
  *
  *  Started by: Thomas Gleixner and Ingo Molnar
- *
- *  Distribute under GPLv2.
  */
 #include <linux/cpu.h>
 #include <linux/err.h>
@@ -124,10 +121,16 @@
 	 * into a long sleep. If two CPUs happen to assign themselves to
 	 * this duty, then the jiffies update is still serialized by
 	 * jiffies_lock.
+	 *
+	 * If nohz_full is enabled, this should not happen because the
+	 * tick_do_timer_cpu never relinquishes.
 	 */
-	if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE)
-	    && !tick_nohz_full_cpu(cpu))
+	if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE)) {
+#ifdef CONFIG_NO_HZ_FULL
+		WARN_ON(tick_nohz_full_running);
+#endif
 		tick_do_timer_cpu = cpu;
+	}
 #endif
 
 	/* Check, if the jiffies need an update */
@@ -398,8 +401,8 @@
 static int tick_nohz_cpu_down(unsigned int cpu)
 {
 	/*
-	 * The boot CPU handles housekeeping duty (unbound timers,
-	 * workqueues, timekeeping, ...) on behalf of full dynticks
+	 * The tick_do_timer_cpu CPU handles housekeeping duty (unbound
+	 * timers, workqueues, timekeeping, ...) on behalf of full dynticks
 	 * CPUs. It must remain online when nohz full is enabled.
 	 */
 	if (tick_nohz_full_running && tick_do_timer_cpu == cpu)
@@ -426,12 +429,15 @@
 		return;
 	}
 
-	cpu = smp_processor_id();
+	if (IS_ENABLED(CONFIG_PM_SLEEP_SMP) &&
+			!IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU)) {
+		cpu = smp_processor_id();
 
-	if (cpumask_test_cpu(cpu, tick_nohz_full_mask)) {
-		pr_warn("NO_HZ: Clearing %d from nohz_full range for timekeeping\n",
-			cpu);
-		cpumask_clear_cpu(cpu, tick_nohz_full_mask);
+		if (cpumask_test_cpu(cpu, tick_nohz_full_mask)) {
+			pr_warn("NO_HZ: Clearing %d from nohz_full range "
+				"for timekeeping\n", cpu);
+			cpumask_clear_cpu(cpu, tick_nohz_full_mask);
+		}
 	}
 
 	for_each_cpu(cpu, tick_nohz_full_mask)
@@ -628,10 +634,12 @@
 	/* Forward the time to expire in the future */
 	hrtimer_forward(&ts->sched_timer, now, tick_period);
 
-	if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
-		hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED);
-	else
+	if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
+		hrtimer_start_expires(&ts->sched_timer,
+				      HRTIMER_MODE_ABS_PINNED_HARD);
+	} else {
 		tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1);
+	}
 
 	/*
 	 * Reset to make sure next tick stop doesn't get fooled by past
@@ -648,7 +656,8 @@
 static ktime_t tick_nohz_next_event(struct tick_sched *ts, int cpu)
 {
 	u64 basemono, next_tick, next_tmr, next_rcu, delta, expires;
-	unsigned long seq, basejiff;
+	unsigned long basejiff;
+	unsigned int seq;
 
 	/* Read jiffies and the time when jiffies were updated last */
 	do {
@@ -775,7 +784,6 @@
 	 */
 	if (!ts->tick_stopped) {
 		calc_load_nohz_start();
-		cpu_load_update_nohz_start();
 		quiet_vmstat();
 
 		ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
@@ -796,7 +804,8 @@
 	}
 
 	if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
-		hrtimer_start(&ts->sched_timer, tick, HRTIMER_MODE_ABS_PINNED);
+		hrtimer_start(&ts->sched_timer, tick,
+			      HRTIMER_MODE_ABS_PINNED_HARD);
 	} else {
 		hrtimer_set_expires(&ts->sched_timer, tick);
 		tick_program_event(tick, 1);
@@ -822,7 +831,6 @@
 {
 	/* Update jiffies first */
 	tick_do_update_jiffies64(now);
-	cpu_load_update_nohz_stop();
 
 	/*
 	 * Clear the timer idle flag, so we avoid IPIs on remote queueing and
@@ -885,7 +893,7 @@
 	if (need_resched())
 		return false;
 
-	if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
+	if (unlikely(local_softirq_pending())) {
 		static int ratelimit;
 
 		if (ratelimit < 10 &&
@@ -907,8 +915,13 @@
 		/*
 		 * Boot safety: make sure the timekeeping duty has been
 		 * assigned before entering dyntick-idle mode,
+		 * tick_do_timer_cpu is TICK_DO_TIMER_BOOT
 		 */
-		if (tick_do_timer_cpu == TICK_DO_TIMER_NONE)
+		if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_BOOT))
+			return false;
+
+		/* Should not happen for nohz-full */
+		if (WARN_ON_ONCE(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
 			return false;
 	}
 
@@ -1026,6 +1039,18 @@
 }
 
 /**
+ * tick_nohz_get_next_hrtimer - return the next expiration time for the hrtimer
+ * or the tick, whatever that expires first. Note that, if the tick has been
+ * stopped, it returns the next hrtimer.
+ *
+ * Called from power state control code with interrupts disabled
+ */
+ktime_t tick_nohz_get_next_hrtimer(void)
+{
+	return __this_cpu_read(tick_cpu_device.evtdev)->next_event;
+}
+
+/**
  * tick_nohz_get_sleep_length - return the expected length of the current sleep
  * @delta_next: duration until the next event if the tick cannot be stopped
  *
@@ -1208,7 +1233,7 @@
 	 * Recycle the hrtimer in ts, so we can share the
 	 * hrtimer_forward with the highres code.
 	 */
-	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 	/* Get the next period */
 	next = tick_init_jiffy_update();
 
@@ -1305,7 +1330,7 @@
 	/*
 	 * Emulate tick processing via per-CPU hrtimers:
 	 */
-	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
 	ts->sched_timer.function = tick_sched_timer;
 
 	/* Get the next period (per-CPU) */
@@ -1320,7 +1345,7 @@
 	}
 
 	hrtimer_forward(&ts->sched_timer, now, tick_period);
-	hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED);
+	hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED_HARD);
 	tick_nohz_activate(ts, NOHZ_MODE_HIGHRES);
 }
 #endif /* HIGH_RES_TIMERS */