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: 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>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.068981667@infradead.org

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 7bf882f..566f7db 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -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;
        }

diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c
index abe5118..fffd4ed 100644 (file)
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c
@@ -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();
 

diff --git a/drivers/cpuidle/dt_idle_states.c b/drivers/cpuidle/dt_idle_states.c
index 7ca3d7d..02aa0b3 100644 (file)
--- a/drivers/cpuidle/dt_idle_states.c
+++ b/drivers/cpuidle/dt_idle_states.c
@@ -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;
        /*

diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index fce4762..0ddc11e 100644 (file)
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -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();                                  \
        }                                                               \