[PATCH 07/10] cpuidle, armada: Push RCU-idle into driver

From: Cheng-Jui Wang
Date: Fri Mar 03 2023 - 04:26:59 EST


From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

commit 4ce40e9dbe83153f60d7e4ccd24a1eb4f8264f6a upstream.

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

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

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Tested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230112195539.946630819@xxxxxxxxxxxxx
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@xxxxxxxxxxxx>
---
drivers/cpuidle/cpuidle-mvebu-v7.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/cpuidle/cpuidle-mvebu-v7.c b/drivers/cpuidle/cpuidle-mvebu-v7.c
index 01a856971f05..c9568aa9410c 100644
--- 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 cpuidle_device *dev,
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_idle_driver = {
.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_idle_driver = {
.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_idle_driver = {
.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_idle_driver = {
.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,
--
2.18.0