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cpuidle, tegra: Push RCU-idle into driver

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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@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20230112195539.699546331@infradead.org
This commit is contained in:
Peter Zijlstra 2023-01-12 20:43:20 +01:00 committed by Ingo Molnar
parent 8e9ab9e8da
commit 5fca0d9f5d
1 changed files with 16 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/cpuidle/cpuidle-tegra.c
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@ -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",