[PATCH v3 05/51] cpuidle,riscv: Push RCU-idle into driver

Peter Zijlstra
Thu, 12 Jan 2023 19:43:19 -0000

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

That is, once implicitly through the cpu_pm_*() calls and once
explicitly doing ct_irq_*_irqon().

Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Reviewed-by: Anup Patel <anup at brainfault.org>
Reviewed-by: Frederic Weisbecker <frederic at kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Tested-by: Tony Lindgren <tony at atomide.com>
Tested-by: Ulf Hansson <ulf.hansson at linaro.org>
---
 drivers/cpuidle/cpuidle-riscv-sbi.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -116,12 +116,12 @@ static int __sbi_enter_domain_idle_state
 		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();

 	if (sbi_is_domain_state_available())
 		state = sbi_get_domain_state();
@@ -130,12 +130,12 @@ static int __sbi_enter_domain_idle_state

 	ret = sbi_suspend(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();

@@ -246,6 +246,7 @@ static int sbi_dt_cpu_init_topology(stru
 	 * 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 = sbi_enter_domain_idle_state;
 	drv->states[state_count - 1].enter_s2idle
sbi_enter_s2idle_domain_idle_state;