3 files changed, 30 insertions, 27 deletions

diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
index fae958794339..146f97068022 100644
--- a/drivers/cpuidle/cpuidle-psci-domain.c
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -67,12 +67,16 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 
 	/*
 	 * Allow power off when OSI has been successfully enabled.
-	 * PREEMPT_RT is not yet ready to enter domain idle states.
+	 * On a PREEMPT_RT based configuration the domain idle states are
+	 * supported, but only during system-wide suspend.
 	 */
-	if (use_osi && !IS_ENABLED(CONFIG_PREEMPT_RT))
+	if (use_osi) {
 		pd->power_off = psci_pd_power_off;
-	else
+		if (IS_ENABLED(CONFIG_PREEMPT_RT))
+			pd->flags |= GENPD_FLAG_RPM_ALWAYS_ON;
+	} else {
 		pd->flags |= GENPD_FLAG_ALWAYS_ON;
+	}
 
 	/* Use governor for CPU PM domains if it has some states to manage. */
 	pd_gov = pd->states ? &pm_domain_cpu_gov : NULL;
@@ -138,7 +142,6 @@ static const struct of_device_id psci_of_match[] = {
 static int psci_cpuidle_domain_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
-	struct device_node *node;
 	bool use_osi = psci_has_osi_support();
 	int ret = 0, pd_count = 0;
 
@@ -149,15 +152,13 @@ static int psci_cpuidle_domain_probe(struct platform_device *pdev)
 	 * Parse child nodes for the "#power-domain-cells" property and
 	 * initialize a genpd/genpd-of-provider pair when it's found.
 	 */
-	for_each_child_of_node(np, node) {
+	for_each_child_of_node_scoped(np, node) {
 		if (!of_property_present(node, "#power-domain-cells"))
 			continue;
 
 		ret = psci_pd_init(node, use_osi);
-		if (ret) {
-			of_node_put(node);
+		if (ret)
 			goto exit;
-		}
 
 		pd_count++;
 	}
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index 782030a27703..2562dc001fc1 100644
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -37,6 +37,7 @@ struct psci_cpuidle_data {
 
 static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
 static DEFINE_PER_CPU(u32, domain_state);
+static bool psci_cpuidle_use_syscore;
 static bool psci_cpuidle_use_cpuhp;
 
 void psci_set_domain_state(u32 state)
@@ -166,6 +167,12 @@ static struct syscore_ops psci_idle_syscore_ops = {
 	.resume = psci_idle_syscore_resume,
 };
 
+static void psci_idle_init_syscore(void)
+{
+	if (psci_cpuidle_use_syscore)
+		register_syscore_ops(&psci_idle_syscore_ops);
+}
+
 static void psci_idle_init_cpuhp(void)
 {
 	int err;
@@ -173,8 +180,6 @@ static void psci_idle_init_cpuhp(void)
 	if (!psci_cpuidle_use_cpuhp)
 		return;
 
-	register_syscore_ops(&psci_idle_syscore_ops);
-
 	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
 					"cpuidle/psci:online",
 					psci_idle_cpuhp_up,
@@ -222,22 +227,23 @@ static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
 	if (!psci_has_osi_support())
 		return 0;
 
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		return 0;
-
 	data->dev = dt_idle_attach_cpu(cpu, "psci");
 	if (IS_ERR_OR_NULL(data->dev))
 		return PTR_ERR_OR_ZERO(data->dev);
 
+	psci_cpuidle_use_syscore = true;
+
 	/*
 	 * Using the deepest state for the CPU to trigger a potential selection
 	 * of a shared state for the domain, assumes the domain states are all
-	 * deeper states.
+	 * deeper states. On PREEMPT_RT the hierarchical topology is limited to
+	 * s2ram and s2idle.
 	 */
-	drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;
-	drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
 	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
-	psci_cpuidle_use_cpuhp = true;
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
+		psci_cpuidle_use_cpuhp = true;
+	}
 
 	return 0;
 }
@@ -313,6 +319,7 @@ static void psci_cpu_deinit_idle(int cpu)
 	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
 
 	dt_idle_detach_cpu(data->dev);
+	psci_cpuidle_use_syscore = false;
 	psci_cpuidle_use_cpuhp = false;
 }
 
@@ -409,6 +416,7 @@ static int psci_cpuidle_probe(struct platform_device *pdev)
 			goto out_fail;
 	}
 
+	psci_idle_init_syscore();
 	psci_idle_init_cpuhp();
 	return 0;
 
diff --git a/drivers/cpuidle/dt_idle_genpd.c b/drivers/cpuidle/dt_idle_genpd.c
index 1af63c189039..203e9b754aea 100644
--- a/drivers/cpuidle/dt_idle_genpd.c
+++ b/drivers/cpuidle/dt_idle_genpd.c
@@ -130,11 +130,10 @@ out:
 
 int dt_idle_pd_init_topology(struct device_node *np)
 {
-	struct device_node *node;
 	struct of_phandle_args child, parent;
 	int ret;
 
-	for_each_child_of_node(np, node) {
+	for_each_child_of_node_scoped(np, node) {
 		if (of_parse_phandle_with_args(node, "power-domains",
 					"#power-domain-cells", 0, &parent))
 			continue;
@@ -143,10 +142,8 @@ int dt_idle_pd_init_topology(struct device_node *np)
 		child.args_count = 0;
 		ret = of_genpd_add_subdomain(&parent, &child);
 		of_node_put(parent.np);
-		if (ret) {
-			of_node_put(node);
+		if (ret)
 			return ret;
-		}
 	}
 
 	return 0;
@@ -154,11 +151,10 @@ int dt_idle_pd_init_topology(struct device_node *np)
 
 int dt_idle_pd_remove_topology(struct device_node *np)
 {
-	struct device_node *node;
 	struct of_phandle_args child, parent;
 	int ret;
 
-	for_each_child_of_node(np, node) {
+	for_each_child_of_node_scoped(np, node) {
 		if (of_parse_phandle_with_args(node, "power-domains",
 					"#power-domain-cells", 0, &parent))
 			continue;
@@ -167,10 +163,8 @@ int dt_idle_pd_remove_topology(struct device_node *np)
 		child.args_count = 0;
 		ret = of_genpd_remove_subdomain(&parent, &child);
 		of_node_put(parent.np);
-		if (ret) {
-			of_node_put(node);
+		if (ret)
 			return ret;
-		}
 	}
 
 	return 0;