Commit 0c5ffc3d authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

cpuidle, dt: Push RCU-idle into driver 



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

Notably: this converts all dt_init_idle_driver() and
__CPU_PM_CPU_IDLE_ENTER() users for they are inextrably intertwined.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Tested-by: default avatarTony Lindgren <tony@atomide.com>
Tested-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.068981667@infradead.org
parent c3d42418

drivers/acpi/processor_idle.c

+2 −0
Original line number Diff line number Diff line
@@ -1219,6 +1219,8 @@ static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) 
		state->target_residency = lpi->min_residency;

		if (lpi->arch_flags)

			state->flags |= CPUIDLE_FLAG_TIMER_STOP;

		if (i != 0 && lpi->entry_method == ACPI_CSTATE_FFH)

			state->flags |= CPUIDLE_FLAG_RCU_IDLE;

		state->enter = acpi_idle_lpi_enter;

		drv->safe_state_index = i;

	}

drivers/cpuidle/cpuidle-big_little.c

+6 −2
Original line number Diff line number Diff line
@@ -64,7 +64,8 @@ static struct cpuidle_driver bl_idle_little_driver = { 
		.enter			= bl_enter_powerdown,

		.exit_latency		= 700,

		.target_residency	= 2500,

		.flags			= CPUIDLE_FLAG_TIMER_STOP,

		.flags			= CPUIDLE_FLAG_TIMER_STOP |

					  CPUIDLE_FLAG_RCU_IDLE,

		.name			= "C1",

		.desc			= "ARM little-cluster power down",

	},
@@ -85,7 +86,8 @@ static struct cpuidle_driver bl_idle_big_driver = { 
		.enter			= bl_enter_powerdown,

		.exit_latency		= 500,

		.target_residency	= 2000,

		.flags			= CPUIDLE_FLAG_TIMER_STOP,

		.flags			= CPUIDLE_FLAG_TIMER_STOP |

					  CPUIDLE_FLAG_RCU_IDLE,

		.name			= "C1",

		.desc			= "ARM big-cluster power down",

	},
@@ -124,11 +126,13 @@ static int bl_enter_powerdown(struct cpuidle_device *dev, 
				struct cpuidle_driver *drv, int idx)

{

	cpu_pm_enter();

	ct_idle_enter();



	cpu_suspend(0, bl_powerdown_finisher);



	/* signals the MCPM core that CPU is out of low power state */

	mcpm_cpu_powered_up();

	ct_idle_exit();



	cpu_pm_exit();

drivers/cpuidle/dt_idle_states.c

+1 −1
Original line number Diff line number Diff line
@@ -77,7 +77,7 @@ static int init_state_node(struct cpuidle_state *idle_state, 
	if (err)

		desc = state_node->name;



	idle_state->flags = 0;

	idle_state->flags = CPUIDLE_FLAG_RCU_IDLE;

	if (of_property_read_bool(state_node, "local-timer-stop"))

		idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;

	/*

include/linux/cpuidle.h

+2 −0
Original line number Diff line number Diff line
@@ -289,7 +289,9 @@ extern s64 cpuidle_governor_latency_req(unsigned int cpu); 
	if (!is_retention)						\

		__ret =  cpu_pm_enter();				\

	if (!__ret) {							\

		ct_idle_enter();					\

		__ret = low_level_idle_enter(state);			\

		ct_idle_exit();						\

		if (!is_retention)					\

			cpu_pm_exit();					\

	}								\