diff mbox series

[13/36] cpuidle,dt: Push RCU-idle into driver

Message ID 20220608144516.743744529@infradead.org (mailing list archive)
State Handled Elsewhere
Headers show
Series cpuidle,rcu: Cleanup the mess | expand

Commit Message

Peter Zijlstra June 8, 2022, 2:27 p.m. UTC
, Arnd Bergmann <arnd@arndb.de>, ulli.kroll@googlemail.com, vgupta@kernel.org, linux-clk@vger.kernel.org, josh@joshtriplett.org, rostedt@goodmis.org, rcu@vger.kernel.org, bp@alien8.de, bcain@quicinc.com, tsbogend@alpha.franken.de, linux-parisc@vger.kernel.org, sudeep.holla@arm.com, shawnguo@kernel.org, davem@davemloft.net, dalias@libc.org, tony@atomide.com, amakhalov@vmware.com, bjorn.andersson@linaro.org, hpa@zytor.com, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, anton.ivanov@cambridgegreys.com, jonas@southpole.se, yury.norov@gmail.com, richard@nod.at, x86@kernel.org, linux@armlinux.org.uk, mingo@redhat.com, aou@eecs.berkeley.edu, paulmck@kernel.org, hca@linux.ibm.com, stefan.kristiansson@saunalahti.fi, openrisc@lists.librecores.org, paul.walmsley@sifive.com, linux-tegra@vger.kernel.org, namhyung@kernel.org, andriy.shevchenko@linux.intel.com, jpoimboe@kernel.org, jgross@suse.com, monstr@monstr.eu, linux-mips@vger.kernel.org, palmer@dab
 belt.com, anup@brainfault.org, ink@jurassic.park.msu.ru, johannes@sipsolutions.net, linuxppc-dev@lists.ozlabs.org
Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org
Sender: "Linuxppc-dev" <linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org>

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

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>
---
 arch/arm/mach-omap2/cpuidle34xx.c    |    4 ++--
 drivers/acpi/processor_idle.c        |    2 ++
 drivers/cpuidle/cpuidle-arm.c        |    1 +
 drivers/cpuidle/cpuidle-big_little.c |    8 ++++++--
 drivers/cpuidle/cpuidle-psci.c       |    1 +
 drivers/cpuidle/cpuidle-qcom-spm.c   |    1 +
 drivers/cpuidle/cpuidle-riscv-sbi.c  |    1 +
 drivers/cpuidle/dt_idle_states.c     |    2 +-
 include/linux/cpuidle.h              |    4 ++++
 9 files changed, 19 insertions(+), 5 deletions(-)
diff mbox series

Patch

--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1200,6 +1200,8 @@  static int acpi_processor_setup_lpi_stat
 		state->target_residency = lpi->min_residency;
 		if (lpi->arch_flags)
 			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
+		if (lpi->entry_method == ACPI_CSTATE_FFH)
+			state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 		state->enter = acpi_idle_lpi_enter;
 		drv->safe_state_index = i;
 	}
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -53,6 +53,7 @@  static struct cpuidle_driver arm_idle_dr
 	 * handler for idle state index 0.
 	 */
 	.states[0] = {
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.enter                  = arm_enter_idle_state,
 		.exit_latency           = 1,
 		.target_residency       = 1,
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c
@@ -64,7 +64,8 @@  static struct cpuidle_driver bl_idle_lit
 		.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
 		.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 cpu
 				struct cpuidle_driver *drv, int idx)
 {
 	cpu_pm_enter();
+	rcu_idle_enter();
 
 	cpu_suspend(0, bl_powerdown_finisher);
 
 	/* signals the MCPM core that CPU is out of low power state */
 	mcpm_cpu_powered_up();
+	rcu_idle_exit();
 
 	cpu_pm_exit();
 
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -357,6 +357,7 @@  static int psci_idle_init_cpu(struct dev
 	 * PSCI idle states relies on architectural WFI to be represented as
 	 * state index 0.
 	 */
+	drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
 	drv->states[0].enter = psci_enter_idle_state;
 	drv->states[0].exit_latency = 1;
 	drv->states[0].target_residency = 1;
--- a/drivers/cpuidle/cpuidle-qcom-spm.c
+++ b/drivers/cpuidle/cpuidle-qcom-spm.c
@@ -72,6 +72,7 @@  static struct cpuidle_driver qcom_spm_id
 	.owner = THIS_MODULE,
 	.states[0] = {
 		.enter			= spm_enter_idle_state,
+		.flags			= CPUIDLE_FLAG_RCU_IDLE,
 		.exit_latency		= 1,
 		.target_residency	= 1,
 		.power_usage		= UINT_MAX,
--- a/drivers/cpuidle/cpuidle-riscv-sbi.c
+++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
@@ -332,6 +332,7 @@  static int sbi_cpuidle_init_cpu(struct d
 	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
 
 	/* RISC-V architectural WFI to be represented as state index 0. */
+	drv->states[0].flags = CPUIDLE_FLAG_RCU_IDLE;
 	drv->states[0].enter = sbi_cpuidle_enter_state;
 	drv->states[0].exit_latency = 1;
 	drv->states[0].target_residency = 1;
--- a/drivers/cpuidle/dt_idle_states.c
+++ b/drivers/cpuidle/dt_idle_states.c
@@ -77,7 +77,7 @@  static int init_state_node(struct cpuidl
 	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;
 	/*
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -282,14 +282,18 @@  extern s64 cpuidle_governor_latency_req(
 	int __ret = 0;							\
 									\
 	if (!idx) {							\
+		rcu_idle_enter();					\
 		cpu_do_idle();						\
+		rcu_idle_exit();					\
 		return idx;						\
 	}								\
 									\
 	if (!is_retention)						\
 		__ret =  cpu_pm_enter();				\
 	if (!__ret) {							\
+		rcu_idle_enter();					\
 		__ret = low_level_idle_enter(state);			\
+		rcu_idle_exit();					\
 		if (!is_retention)					\
 			cpu_pm_exit();					\
 	}								\