Merge back cpuidle material for 5.10.

Author: rafaeljw

drivers/acpi/processor_idle.c

@@ -176,6 +176,7 @@ static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 static bool lapic_timer_needs_broadcast(struct acpi_processor *pr,
 					struct acpi_processor_cx *cx)
 {
+	return false;
 }
 
 #endif

drivers/cpuidle/cpuidle-psci.c

@@ -66,15 +66,15 @@ static int psci_enter_domain_idle_state(struct cpuidle_device *dev,
 		return -1;
 
 	/* Do runtime PM to manage a hierarchical CPU toplogy. */
-	pm_runtime_put_sync_suspend(pd_dev);
+	RCU_NONIDLE(pm_runtime_put_sync_suspend(pd_dev));
 
 	state = psci_get_domain_state();
 	if (!state)
 		state = states[idx];
 
 	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
 
-	pm_runtime_get_sync(pd_dev);
+	RCU_NONIDLE(pm_runtime_get_sync(pd_dev));
 
 	cpu_pm_exit();
 

drivers/cpuidle/cpuidle.c

@@ -142,11 +142,6 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv,
 
 	time_start = ns_to_ktime(local_clock());
 
-	/*
-	 * trace_suspend_resume() called by tick_freeze() for the last CPU
-	 * executing it contains RCU usage regarded as invalid in the idle
-	 * context, so tell RCU about that.
-	 */
 	tick_freeze();
 	/*
 	 * The state used here cannot be a "coupled" one, because the "coupled"
@@ -159,11 +154,6 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv,
 	target_state->enter_s2idle(dev, drv, index);
 	if (WARN_ON_ONCE(!irqs_disabled()))
 		local_irq_disable();
-	/*
-	 * timekeeping_resume() that will be called by tick_unfreeze() for the
-	 * first CPU executing it calls functions containing RCU read-side
-	 * critical sections, so tell RCU about that.
-	 */
 	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))
 		rcu_idle_exit();
 	tick_unfreeze();

kernel/rcu/tree.c

@@ -673,6 +673,7 @@ void rcu_idle_enter(void)
 	lockdep_assert_irqs_disabled();
 	rcu_eqs_enter(false);
 }
+EXPORT_SYMBOL_GPL(rcu_idle_enter);
 
 #ifdef CONFIG_NO_HZ_FULL
 /**
@@ -886,6 +887,7 @@ void rcu_idle_exit(void)
 	rcu_eqs_exit(false);
 	local_irq_restore(flags);
 }
+EXPORT_SYMBOL_GPL(rcu_idle_exit);
 
 #ifdef CONFIG_NO_HZ_FULL
 /**