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

From: Peter Zijlstra
Date: Thu Jan 12 2023 - 15:05:20 EST


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@xxxxxxxxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Tested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
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;