Merge tag 'pmdomain-v6.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/linux-pm

Pull pmdomain / cpuidle-psci fixes from Ulf Hansson:
 "pmdomain core:

   - Respect CPU latency QoS limit in the genpd governor for CPUs

  cpuidle-psci:

   - Fix cpuhotplug support for PREEMPT_RT"

* tag 'pmdomain-v6.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/linux-pm:
  cpuidle: psci: Fix cpuhotplug routine with PREEMPT_RT=y
  pmdomain: governor: Consider CPU latency tolerance from pm_domain_cpu_gov

Author: torvalds

drivers/cpuidle/cpuidle-psci.c

@@ -45,7 +45,6 @@ struct psci_cpuidle_domain_state {
 static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
 static DEFINE_PER_CPU(struct psci_cpuidle_domain_state, psci_domain_state);
 static bool psci_cpuidle_use_syscore;
-static bool psci_cpuidle_use_cpuhp;
 
 void psci_set_domain_state(struct generic_pm_domain *pd, unsigned int state_idx,
 			   u32 state)
@@ -124,8 +123,12 @@ static int psci_idle_cpuhp_up(unsigned int cpu)
 {
 	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
 
-	if (pd_dev)
-		pm_runtime_get_sync(pd_dev);
+	if (pd_dev) {
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+			pm_runtime_get_sync(pd_dev);
+		else
+			dev_pm_genpd_resume(pd_dev);
+	}
 
 	return 0;
 }
@@ -135,7 +138,11 @@ static int psci_idle_cpuhp_down(unsigned int cpu)
 	struct device *pd_dev = __this_cpu_read(psci_cpuidle_data.dev);
 
 	if (pd_dev) {
-		pm_runtime_put_sync(pd_dev);
+		if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+			pm_runtime_put_sync(pd_dev);
+		else
+			dev_pm_genpd_suspend(pd_dev);
+
 		/* Clear domain state to start fresh at next online. */
 		psci_clear_domain_state();
 	}
@@ -196,9 +203,6 @@ static void psci_idle_init_cpuhp(void)
 {
 	int err;
 
-	if (!psci_cpuidle_use_cpuhp)
-		return;
-
 	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
 					"cpuidle/psci:online",
 					psci_idle_cpuhp_up,
@@ -259,10 +263,8 @@ static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
 	 * s2ram and s2idle.
 	 */
 	drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
-	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 		drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
-		psci_cpuidle_use_cpuhp = true;
-	}
 
 	return 0;
 }
@@ -339,7 +341,6 @@ static void psci_cpu_deinit_idle(int cpu)
 
 	dt_idle_detach_cpu(data->dev);
 	psci_cpuidle_use_syscore = false;
-	psci_cpuidle_use_cpuhp = false;
 }
 
 static int psci_idle_init_cpu(struct device *dev, int cpu)

drivers/pmdomain/governor.c

@@ -8,6 +8,7 @@
 #include <linux/pm_domain.h>
 #include <linux/pm_qos.h>
 #include <linux/hrtimer.h>
+#include <linux/cpu.h>
 #include <linux/cpuidle.h>
 #include <linux/cpumask.h>
 #include <linux/ktime.h>
@@ -349,6 +350,8 @@ static bool cpu_power_down_ok(struct dev_pm_domain *pd)
 	struct cpuidle_device *dev;
 	ktime_t domain_wakeup, next_hrtimer;
 	ktime_t now = ktime_get();
+	struct device *cpu_dev;
+	s64 cpu_constraint, global_constraint;
 	s64 idle_duration_ns;
 	int cpu, i;
 
@@ -359,6 +362,7 @@ static bool cpu_power_down_ok(struct dev_pm_domain *pd)
 	if (!(genpd->flags & GENPD_FLAG_CPU_DOMAIN))
 		return true;
 
+	global_constraint = cpu_latency_qos_limit();
 	/*
 	 * Find the next wakeup for any of the online CPUs within the PM domain
 	 * and its subdomains. Note, we only need the genpd->cpus, as it already
@@ -372,8 +376,16 @@ static bool cpu_power_down_ok(struct dev_pm_domain *pd)
 			if (ktime_before(next_hrtimer, domain_wakeup))
 				domain_wakeup = next_hrtimer;
 		}
+
+		cpu_dev = get_cpu_device(cpu);
+		if (cpu_dev) {
+			cpu_constraint = dev_pm_qos_raw_resume_latency(cpu_dev);
+			if (cpu_constraint < global_constraint)
+				global_constraint = cpu_constraint;
+		}
 	}
 
+	global_constraint *= NSEC_PER_USEC;
 	/* The minimum idle duration is from now - until the next wakeup. */
 	idle_duration_ns = ktime_to_ns(ktime_sub(domain_wakeup, now));
 	if (idle_duration_ns <= 0)
@@ -389,8 +401,10 @@ static bool cpu_power_down_ok(struct dev_pm_domain *pd)
 	 */
 	i = genpd->state_idx;
 	do {
-		if (idle_duration_ns >= (genpd->states[i].residency_ns +
-		    genpd->states[i].power_off_latency_ns)) {
+		if ((idle_duration_ns >= (genpd->states[i].residency_ns +
+		    genpd->states[i].power_off_latency_ns)) &&
+		    (global_constraint >= (genpd->states[i].power_on_latency_ns +
+		    genpd->states[i].power_off_latency_ns))) {
 			genpd->state_idx = i;
 			genpd->gd->last_enter = now;
 			genpd->gd->reflect_residency = true;