[tip: sched/core] cpuidle, psci: Push RCU-idle into driver

[tip-bot2 for Peter Zijlstra]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     e038f7b8028a1d1bc8ac82351c71ea538f19a879
Gitweb:        https://git.kernel.org/tip/e038f7b8028a1d1bc8ac82351c71ea538f19a879
Author:        Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate:    Thu, 12 Jan 2023 20:43:21 +01:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Fri, 13 Jan 2023 11:03:22 +01:00

cpuidle, psci: Push RCU-idle into driver

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@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Kajetan Puchalski <kajetan.puchalski@xxxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Tested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Reviewed-by: Guo Ren <guoren@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230112195539.760296658@xxxxxxxxxxxxx
---
 drivers/cpuidle/cpuidle-psci.c |  9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index 57bc3e3..969808c 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)
@@ -82,12 +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();
 
@@ -240,6 +240,7 @@ 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;