Commit c3d42418 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

cpuidle, OMAP4: Push RCU-idle into driver 



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

Notably three times explicitly using RCU_NONIDLE() and once implicitly
through cpu_pm_*().

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>
Reviewed-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20230112195540.007918454@infradead.org
parent 4ce40e9d

arch/arm/mach-omap2/cpuidle44xx.c

+18 −11
Original line number Diff line number Diff line
@@ -105,7 +105,9 @@ static int omap_enter_idle_smp(struct cpuidle_device *dev, 
	}

	raw_spin_unlock_irqrestore(&mpu_lock, flag);



	ct_idle_enter();

	omap4_enter_lowpower(dev->cpu, cx->cpu_state);

	ct_idle_exit();



	raw_spin_lock_irqsave(&mpu_lock, flag);

	if (cx->mpu_state_vote == num_online_cpus())
@@ -151,10 +153,10 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, 
				 (cx->mpu_logic_state == PWRDM_POWER_OFF);



	/* Enter broadcast mode for periodic timers */

	RCU_NONIDLE(tick_broadcast_enable());

	tick_broadcast_enable();



	/* Enter broadcast mode for one-shot timers */

	RCU_NONIDLE(tick_broadcast_enter());

	tick_broadcast_enter();



	/*

	 * Call idle CPU PM enter notifier chain so that
@@ -166,7 +168,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, 


	if (dev->cpu == 0) {

		pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);

		RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));

		omap_set_pwrdm_state(mpu_pd, cx->mpu_state);



		/*

		 * Call idle CPU cluster PM enter notifier chain
@@ -178,14 +180,16 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, 
				index = 0;

				cx = state_ptr + index;

				pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);

				RCU_NONIDLE(omap_set_pwrdm_state(mpu_pd, cx->mpu_state));

				omap_set_pwrdm_state(mpu_pd, cx->mpu_state);

				mpuss_can_lose_context = 0;

			}

		}

	}



	ct_idle_enter();

	omap4_enter_lowpower(dev->cpu, cx->cpu_state);

	cpu_done[dev->cpu] = true;

	ct_idle_exit();



	/* Wakeup CPU1 only if it is not offlined */

	if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
@@ -194,9 +198,9 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, 
		    mpuss_can_lose_context)

			gic_dist_disable();



		RCU_NONIDLE(clkdm_deny_idle(cpu_clkdm[1]));

		RCU_NONIDLE(omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON));

		RCU_NONIDLE(clkdm_allow_idle(cpu_clkdm[1]));

		clkdm_deny_idle(cpu_clkdm[1]);

		omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON);

		clkdm_allow_idle(cpu_clkdm[1]);



		if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&

		    mpuss_can_lose_context) {
@@ -222,7 +226,7 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, 
	cpu_pm_exit();



cpu_pm_out:

	RCU_NONIDLE(tick_broadcast_exit());

	tick_broadcast_exit();



fail:

	cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
@@ -247,7 +251,8 @@ static struct cpuidle_driver omap4_idle_driver = { 
			/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */

			.exit_latency = 328 + 440,

			.target_residency = 960,

			.flags = CPUIDLE_FLAG_COUPLED,

			.flags = CPUIDLE_FLAG_COUPLED |

				 CPUIDLE_FLAG_RCU_IDLE,

			.enter = omap_enter_idle_coupled,

			.name = "C2",

			.desc = "CPUx OFF, MPUSS CSWR",
@@ -256,7 +261,8 @@ static struct cpuidle_driver omap4_idle_driver = { 
			/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */

			.exit_latency = 460 + 518,

			.target_residency = 1100,

			.flags = CPUIDLE_FLAG_COUPLED,

			.flags = CPUIDLE_FLAG_COUPLED |

				 CPUIDLE_FLAG_RCU_IDLE,

			.enter = omap_enter_idle_coupled,

			.name = "C3",

			.desc = "CPUx OFF, MPUSS OSWR",
@@ -282,7 +288,8 @@ static struct cpuidle_driver omap5_idle_driver = { 
			/* C2 - CPU0 RET + CPU1 RET + MPU CSWR */

			.exit_latency = 48 + 60,

			.target_residency = 100,

			.flags = CPUIDLE_FLAG_TIMER_STOP,

			.flags = CPUIDLE_FLAG_TIMER_STOP |

				 CPUIDLE_FLAG_RCU_IDLE,

			.enter = omap_enter_idle_smp,

			.name = "C2",

			.desc = "CPUx CSWR, MPUSS CSWR",