[PATCH 04/10] cpuidle, psci: Push RCU-idle into driver

[Cheng-Jui Wang]

From: Peter Zijlstra <peterz at infradead.org>

commit e038f7b8028a1d1bc8ac82351c71ea538f19a879 upstream.

Doing RCU-idle outside the driver, only to then temporarily enable it
again, at least twice, before going idle is suboptimal.

Notably once implicitly through the cpu_pm_*() calls and once
explicitly doing ct_irq_*_irqon().

Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Tested-by: Kajetan Puchalski <kajetan.puchalski at arm.com>
Tested-by: Tony Lindgren <tony at atomide.com>
Tested-by: Ulf Hansson <ulf.hansson at linaro.org>
Reviewed-by: Frederic Weisbecker <frederic at kernel.org>
Reviewed-by: Guo Ren <guoren at kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Link: https://lore.kernel.org/r/20230112195539.760296658@infradead.org
Signed-off-by: Suren Baghdasaryan <surenb at google.com>
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang at mediatek.com>
---
 drivers/cpuidle/cpuidle-psci.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index 57bc3e3ae391..6a259c94b8b2 100644
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -69,12 +69,12 @@ static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
 		return -1;
 
 	/* Do runtime PM to manage a hierarchical CPU toplogy. */
-	ct_irq_enter_irqson();
 	if (s2idle)
 		dev_pm_genpd_suspend(pd_dev);
 	else
 		pm_runtime_put_sync_suspend(pd_dev);
-	ct_irq_exit_irqson();
+
+	ct_idle_enter();
 
 	state = psci_get_domain_state();
 	if (!state)
@@ -82,13 +82,12 @@ static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
 
 	ret = psci_cpu_suspend_enter(state) ? -1 : idx;
 
-	ct_irq_enter_irqson();
+	ct_idle_exit();
+
 	if (s2idle)
 		dev_pm_genpd_resume(pd_dev);
 	else
 		pm_runtime_get_sync(pd_dev);
-	ct_irq_exit_irqson();
-
 	cpu_pm_exit();
 
 	/* Clear the domain state to start fresh when back from idle. */
@@ -240,6 +239,7 @@ static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
 	 * of a shared state for the domain, assumes the domain states are all
 	 * deeper states.
 	 */
+	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;
-- 
2.18.0