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Date: Fri, 3 Mar 2023 17:23:25 +0800
From: Cheng-Jui Wang <cheng-jui.wang@...iatek.com>
To: <stable@...r.kernel.org>, "Rafael J. Wysocki" <rafael@...nel.org>,
"Daniel Lezcano" <daniel.lezcano@...aro.org>,
Thierry Reding <thierry.reding@...il.com>,
Jonathan Hunter <jonathanh@...dia.com>,
"Matthias Brugger" <matthias.bgg@...il.com>
CC: Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...nel.org>,
Suren Baghdasaryan <surenb@...gle.com>,
Cheng-Jui Wang <cheng-jui.wang@...iatek.com>,
<linux-pm@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
<linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-mediatek@...ts.infradead.org>
Subject: [PATCH 03/10] cpuidle, tegra: Push RCU-idle into driver
From: Peter Zijlstra <peterz@...radead.org>
commit 5fca0d9f5d76664786ca6c09076341def165a677 upstream.
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 RCU_NONIDLE().
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Tested-by: Tony Lindgren <tony@...mide.com>
Tested-by: Ulf Hansson <ulf.hansson@...aro.org>
Reviewed-by: Frederic Weisbecker <frederic@...nel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Link: https://lore.kernel.org/r/20230112195539.699546331@infradead.org
Signed-off-by: Suren Baghdasaryan <surenb@...gle.com>
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@...iatek.com>
---
drivers/cpuidle/cpuidle-tegra.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c
index 9845629aeb6d..3ca5cfb9d322 100644
--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -180,9 +180,11 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
}
local_fiq_disable();
- RCU_NONIDLE(tegra_pm_set_cpu_in_lp2());
+ tegra_pm_set_cpu_in_lp2();
cpu_pm_enter();
+ ct_idle_enter();
+
switch (index) {
case TEGRA_C7:
err = tegra_cpuidle_c7_enter();
@@ -197,8 +199,10 @@ static int tegra_cpuidle_state_enter(struct cpuidle_device *dev,
break;
}
+ ct_idle_exit();
+
cpu_pm_exit();
- RCU_NONIDLE(tegra_pm_clear_cpu_in_lp2());
+ tegra_pm_clear_cpu_in_lp2();
local_fiq_enable();
return err ?: index;
@@ -226,6 +230,7 @@ static int tegra_cpuidle_enter(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
+ bool do_rcu = drv->states[index].flags & CPUIDLE_FLAG_RCU_IDLE;
unsigned int cpu = cpu_logical_map(dev->cpu);
int ret;
@@ -233,9 +238,13 @@ static int tegra_cpuidle_enter(struct cpuidle_device *dev,
if (dev->states_usage[index].disable)
return -1;
- if (index == TEGRA_C1)
+ if (index == TEGRA_C1) {
+ if (do_rcu)
+ ct_idle_enter();
ret = arm_cpuidle_simple_enter(dev, drv, index);
- else
+ if (do_rcu)
+ ct_idle_exit();
+ } else
ret = tegra_cpuidle_state_enter(dev, index, cpu);
if (ret < 0) {
@@ -285,7 +294,8 @@ static struct cpuidle_driver tegra_idle_driver = {
.exit_latency = 2000,
.target_residency = 2200,
.power_usage = 100,
- .flags = CPUIDLE_FLAG_TIMER_STOP,
+ .flags = CPUIDLE_FLAG_TIMER_STOP |
+ CPUIDLE_FLAG_RCU_IDLE,
.name = "C7",
.desc = "CPU core powered off",
},
@@ -295,6 +305,7 @@ static struct cpuidle_driver tegra_idle_driver = {
.target_residency = 10000,
.power_usage = 0,
.flags = CPUIDLE_FLAG_TIMER_STOP |
+ CPUIDLE_FLAG_RCU_IDLE |
CPUIDLE_FLAG_COUPLED,
.name = "CC6",
.desc = "CPU cluster powered off",
--
2.18.0
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