Merge tag 'pm-5.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix a recent regression that broke suspend-to-idle on some x86
  systems, fix the intel_pstate driver to correctly let the platform
  firmware control CPU performance in some cases and add __init
  annotations to a couple of functions.

  Specifics:

   - Make sure that the _TIF_POLLING_NRFLAG is clear before entering the
     last phase of suspend-to-idle to avoid wakeup issues on some x86
     systems (Chen Yu, Rafael Wysocki).

   - Cover one more case in which the intel_pstate driver should let the
     platform firmware control the CPU frequency and refuse to load
     (Srinivas Pandruvada).

   - Add __init annotations to 2 functions in the power management core
     (Christophe JAILLET)"

* tag 'pm-5.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: Rearrange s2idle-specific idle state entry code
  PM: sleep: core: mark 2 functions as __init to save some memory
  cpufreq: intel_pstate: Add one more OOB control bit
  PM: s2idle: Clear _TIF_POLLING_NRFLAG before suspend to idle

drivers/base/power/trace.c

@@ -265,14 +265,14 @@ static struct notifier_block pm_trace_nb = {
 	.notifier_call = pm_trace_notify,
 };
 
-static int early_resume_init(void)
+static int __init early_resume_init(void)
 {
 	hash_value_early_read = read_magic_time();
 	register_pm_notifier(&pm_trace_nb);
 	return 0;
 }
 
-static int late_resume_init(void)
+static int __init late_resume_init(void)
 {
 	unsigned int val = hash_value_early_read;
 	unsigned int user, file, dev;

drivers/cpufreq/intel_pstate.c

@@ -2677,6 +2677,8 @@ static struct acpi_platform_list plat_info[] __initdata = {
 	{ } /* End */
 };
 
+#define BITMASK_OOB	(BIT(8) | BIT(18))
+
 static bool __init intel_pstate_platform_pwr_mgmt_exists(void)
 {
 	const struct x86_cpu_id *id;
@@ -2686,8 +2688,9 @@ static bool __init intel_pstate_platform_pwr_mgmt_exists(void)
 	id = x86_match_cpu(intel_pstate_cpu_oob_ids);
 	if (id) {
 		rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
-		if (misc_pwr & (1 << 8)) {
-			pr_debug("Bit 8 in the MISC_PWR_MGMT MSR set\n");
+		if (misc_pwr & BITMASK_OOB) {
+			pr_debug("Bit 8 or 18 in the MISC_PWR_MGMT MSR set\n");
+			pr_debug("P states are controlled in Out of Band mode by the firmware/hardware\n");
 			return true;
 		}
 	}

drivers/cpuidle/cpuidle.c

@@ -186,9 +186,10 @@ int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	 * be frozen safely.
 	 */
 	index = find_deepest_state(drv, dev, U64_MAX, 0, true);
-	if (index > 0)
+	if (index > 0) {
 		enter_s2idle_proper(drv, dev, index);
-
+		local_irq_enable();
+	}
 	return index;
 }
 #endif /* CONFIG_SUSPEND */

kernel/sched/idle.c

@@ -96,6 +96,15 @@ void __cpuidle default_idle_call(void)
 	}
 }
 
+static int call_cpuidle_s2idle(struct cpuidle_driver *drv,
+			       struct cpuidle_device *dev)
+{
+	if (current_clr_polling_and_test())
+		return -EBUSY;
+
+	return cpuidle_enter_s2idle(drv, dev);
+}
+
 static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 		      int next_state)
 {
@@ -171,11 +180,9 @@ static void cpuidle_idle_call(void)
 		if (idle_should_enter_s2idle()) {
 			rcu_idle_enter();
 
-			entered_state = cpuidle_enter_s2idle(drv, dev);
-			if (entered_state > 0) {
-				local_irq_enable();
+			entered_state = call_cpuidle_s2idle(drv, dev);
+			if (entered_state > 0)
 				goto exit_idle;
-			}
 
 			rcu_idle_exit();