From dd3ad97c5621aa853843dd5e6783ca787466158c Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Sun, 25 Dec 2011 21:00:40 +0530 Subject: [PATCH] ARM: OMAP4: CPUidle: Use coupled cpuidle states to implement SMP cpuidle. OMAP4 CPUDILE driver is converted mainly based on notes from the coupled cpuidle patch series. The changes include : - Register both CPUs and C-states to cpuidle driver. - Set struct cpuidle_device.coupled_cpus - Set struct cpuidle_device.safe_state to non coupled state. - Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each state that affects multiple cpus. - Separate ->enter hooks for coupled & simple idle. - CPU0 wait loop for CPU1 power transition. - CPU1 wakeup mechanism for the idle exit. - Enabling ARCH_NEEDS_CPU_IDLE_COUPLED for OMAP4. Thanks to Kevin Hilman and Colin Cross on the suggestions/fixes on the intermediate version of this patch. Signed-off-by: Santosh Shilimkar Signed-off-by: Kevin Hilman --- arch/arm/mach-omap2/Kconfig | 1 + arch/arm/mach-omap2/cpuidle44xx.c | 112 ++++++++++++++++++++++---------------- 2 files changed, 67 insertions(+), 46 deletions(-) diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig index 4cf5142..cc83f5e 100644 --- a/arch/arm/mach-omap2/Kconfig +++ b/arch/arm/mach-omap2/Kconfig @@ -55,6 +55,7 @@ config ARCH_OMAP4 select PM_OPP if PM select USB_ARCH_HAS_EHCI if USB_SUPPORT select ARM_CPU_SUSPEND if PM + select ARCH_NEEDS_CPU_IDLE_COUPLED comment "OMAP Core Type" depends on ARCH_OMAP2 diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c index be1617c..25655eb 100644 --- a/arch/arm/mach-omap2/cpuidle44xx.c +++ b/arch/arm/mach-omap2/cpuidle44xx.c @@ -21,6 +21,7 @@ #include "common.h" #include "pm.h" #include "prm.h" +#include "clockdomain.h" #ifdef CONFIG_CPU_IDLE @@ -49,10 +50,11 @@ static struct omap4_idle_statedata omap4_idle_data[] = { }, }; -static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd; +static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS]; +static struct clockdomain *cpu_clkdm[NR_CPUS]; /** - * omap4_enter_idle - Programs OMAP4 to enter the specified state + * omap4_enter_idle_coupled_[simple/coupled] - OMAP4 cpuidle entry functions * @dev: cpuidle device * @drv: cpuidle driver * @index: the index of state to be entered @@ -61,60 +63,71 @@ static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd; * specified low power state selected by the governor. * Returns the amount of time spent in the low power state. */ -static int omap4_enter_idle(struct cpuidle_device *dev, +static int omap4_enter_idle_simple(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + local_fiq_disable(); + omap_do_wfi(); + local_fiq_enable(); + + return index; +} + +static int omap4_enter_idle_coupled(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { struct omap4_idle_statedata *cx = &omap4_idle_data[index]; - u32 cpu1_state; int cpu_id = smp_processor_id(); local_fiq_disable(); /* - * CPU0 has to stay ON (i.e in C1) until CPU1 is OFF state. + * CPU0 has to wait and stay ON until CPU1 is OFF state. * This is necessary to honour hardware recommondation * of triggeing all the possible low power modes once CPU1 is * out of coherency and in OFF mode. - * Update dev->last_state so that governor stats reflects right - * data. */ - cpu1_state = pwrdm_read_pwrst(cpu1_pd); - if (cpu1_state != PWRDM_POWER_OFF) { - index = drv->safe_state_index; - cx = &omap4_idle_data[index]; + if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { + while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) + cpu_relax(); } - if (index > 0) - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id); + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id); /* * Call idle CPU PM enter notifier chain so that * VFP and per CPU interrupt context is saved. */ - if (cx->cpu_state == PWRDM_POWER_OFF) - cpu_pm_enter(); - - pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); - omap_set_pwrdm_state(mpu_pd, cx->mpu_state); - - /* - * Call idle CPU cluster PM enter notifier chain - * to save GIC and wakeupgen context. - */ - if ((cx->mpu_state == PWRDM_POWER_RET) && - (cx->mpu_logic_state == PWRDM_POWER_OFF)) - cpu_cluster_pm_enter(); + cpu_pm_enter(); + + if (dev->cpu == 0) { + pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state); + omap_set_pwrdm_state(mpu_pd, cx->mpu_state); + + /* + * Call idle CPU cluster PM enter notifier chain + * to save GIC and wakeupgen context. + */ + if ((cx->mpu_state == PWRDM_POWER_RET) && + (cx->mpu_logic_state == PWRDM_POWER_OFF)) + cpu_cluster_pm_enter(); + } omap4_enter_lowpower(dev->cpu, cx->cpu_state); + /* Wakeup CPU1 only if it is not offlined */ + if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { + clkdm_wakeup(cpu_clkdm[1]); + clkdm_allow_idle(cpu_clkdm[1]); + } + /* * Call idle CPU PM exit notifier chain to restore - * VFP and per CPU IRQ context. Only CPU0 state is - * considered since CPU1 is managed by CPU hotplug. + * VFP and per CPU IRQ context. */ - if (pwrdm_read_prev_pwrst(cpu0_pd) == PWRDM_POWER_OFF) - cpu_pm_exit(); + cpu_pm_exit(); /* * Call idle CPU cluster PM exit notifier chain @@ -123,8 +136,7 @@ static int omap4_enter_idle(struct cpuidle_device *dev, if (omap4_mpuss_read_prev_context_state()) cpu_cluster_pm_exit(); - if (index > 0) - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id); + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id); local_fiq_enable(); @@ -143,7 +155,7 @@ struct cpuidle_driver omap4_idle_driver = { .exit_latency = 2 + 2, .target_residency = 5, .flags = CPUIDLE_FLAG_TIME_VALID, - .enter = omap4_enter_idle, + .enter = omap4_enter_idle_simple, .name = "C1", .desc = "MPUSS ON" }, @@ -151,8 +163,8 @@ struct cpuidle_driver omap4_idle_driver = { /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */ .exit_latency = 328 + 440, .target_residency = 960, - .flags = CPUIDLE_FLAG_TIME_VALID, - .enter = omap4_enter_idle, + .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED, + .enter = omap4_enter_idle_coupled, .name = "C2", .desc = "MPUSS CSWR", }, @@ -160,8 +172,8 @@ struct cpuidle_driver omap4_idle_driver = { /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */ .exit_latency = 460 + 518, .target_residency = 1100, - .flags = CPUIDLE_FLAG_TIME_VALID, - .enter = omap4_enter_idle, + .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED, + .enter = omap4_enter_idle_coupled, .name = "C3", .desc = "MPUSS OSWR", }, @@ -182,19 +194,27 @@ int __init omap4_idle_init(void) unsigned int cpu_id = 0; mpu_pd = pwrdm_lookup("mpu_pwrdm"); - cpu0_pd = pwrdm_lookup("cpu0_pwrdm"); - cpu1_pd = pwrdm_lookup("cpu1_pwrdm"); - if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd)) + cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm"); + cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm"); + if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1])) + return -ENODEV; + + cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm"); + cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm"); + if (!cpu_clkdm[0] || !cpu_clkdm[1]) return -ENODEV; - dev = &per_cpu(omap4_idle_dev, cpu_id); - dev->cpu = cpu_id; + for_each_cpu(cpu_id, cpu_online_mask) { + dev = &per_cpu(omap4_idle_dev, cpu_id); + dev->cpu = cpu_id; + dev->coupled_cpus = *cpu_online_mask; - cpuidle_register_driver(&omap4_idle_driver); + cpuidle_register_driver(&omap4_idle_driver); - if (cpuidle_register_device(dev)) { - pr_err("%s: CPUidle register device failed\n", __func__); - return -EIO; + if (cpuidle_register_device(dev)) { + pr_err("%s: CPUidle register failed\n", __func__); + return -EIO; + } } return 0; -- 2.7.4