[PATCH v3 10/51] cpuidle,armada: Push RCU-idle into driver

Peter Zijlstra
Thu, 12 Jan 2023 19:43:24 -0000

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

Notably the cpu_pm_*() calls implicitly re-enable RCU for a bit.

Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.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-mvebu-v7.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/cpuidle/cpuidle-mvebu-v7.c
+++ b/drivers/cpuidle/cpuidle-mvebu-v7.c
@@ -36,7 +36,10 @@ static int mvebu_v7_enter_idle(struct cp
 	if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE)
 		deepidle = true;

+	ct_idle_enter();
 	ret = mvebu_v7_cpu_suspend(deepidle);
+	ct_idle_exit();
+
 	cpu_pm_exit();

 	if (ret)
@@ -49,6 +52,7 @@ static struct cpuidle_driver armadaxp_id
 	.name			= "armada_xp_idle",
 	.states[0]		= ARM_CPUIDLE_WFI_STATE,
 	.states[1]		= {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter			= mvebu_v7_enter_idle,
 		.exit_latency		= 100,
 		.power_usage		= 50,
@@ -57,6 +61,7 @@ static struct cpuidle_driver armadaxp_id
 		.desc			= "CPU power down",
 	},
 	.states[2]		= {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter			= mvebu_v7_enter_idle,
 		.exit_latency		= 1000,
 		.power_usage		= 5,
@@ -72,6 +77,7 @@ static struct cpuidle_driver armada370_i
 	.name			= "armada_370_idle",
 	.states[0]		= ARM_CPUIDLE_WFI_STATE,
 	.states[1]		= {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter			= mvebu_v7_enter_idle,
 		.exit_latency		= 100,
 		.power_usage		= 5,
@@ -87,6 +93,7 @@ static struct cpuidle_driver armada38x_i
 	.name			= "armada_38x_idle",
 	.states[0]		= ARM_CPUIDLE_WFI_STATE,
 	.states[1]		= {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter			= mvebu_v7_enter_idle,
 		.exit_latency		= 10,
 		.power_usage		= 5,