[PATCH 12/16 v2] cpuidle: coupled: Convert to hotplug state machine
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2016-08-24 09:14:53
Also in:
lkml
Subsystem:
cpu hotplug, cpu idle time management framework, the rest · Maintainers:
Thomas Gleixner, Peter Zijlstra, "Rafael J. Wysocki", Daniel Lezcano, Linus Torvalds
Install the callbacks via the state machine.
Cc: "Rafael J. Wysocki" <redacted>
Cc: Daniel Lezcano <redacted>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
v1…v2: - refactor the code to drop the out label.
- make error path in cpuidle_coupled_init() simpler
drivers/cpuidle/coupled.c | 75 +++++++++++++++++++---------------------------
include/linux/cpuhotplug.h | 1 +
2 files changed, 32 insertions(+), 44 deletions(-)
diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index d5657d50ac40..5ba1a8913421 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c@@ -749,65 +749,52 @@ static void cpuidle_coupled_allow_idle(struct cpuidle_coupled *coupled) put_cpu(); } -/** - * cpuidle_coupled_cpu_notify - notifier called during hotplug transitions - * @nb: notifier block - * @action: hotplug transition - * @hcpu: target cpu number - * - * Called when a cpu is brought on or offline using hotplug. Updates the - * coupled cpu set appropriately - */ -static int cpuidle_coupled_cpu_notify(struct notifier_block *nb, - unsigned long action, void *hcpu) +static int coupled_cpu_online(unsigned int cpu) { - int cpu = (unsigned long)hcpu; struct cpuidle_device *dev; - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_UP_PREPARE: - case CPU_DOWN_PREPARE: - case CPU_ONLINE: - case CPU_DEAD: - case CPU_UP_CANCELED: - case CPU_DOWN_FAILED: - break; - default: - return NOTIFY_OK; - } - mutex_lock(&cpuidle_lock); dev = per_cpu(cpuidle_devices, cpu); - if (!dev || !dev->coupled) - goto out; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_UP_PREPARE: - case CPU_DOWN_PREPARE: - cpuidle_coupled_prevent_idle(dev->coupled); - break; - case CPU_ONLINE: - case CPU_DEAD: + if (dev && dev->coupled) { cpuidle_coupled_update_online_cpus(dev->coupled); - /* Fall through */ - case CPU_UP_CANCELED: - case CPU_DOWN_FAILED: cpuidle_coupled_allow_idle(dev->coupled); - break; } -out: mutex_unlock(&cpuidle_lock); - return NOTIFY_OK; + return 0; } -static struct notifier_block cpuidle_coupled_cpu_notifier = { - .notifier_call = cpuidle_coupled_cpu_notify, -}; +static int coupled_cpu_up_prepare(unsigned int cpu) +{ + struct cpuidle_device *dev; + + mutex_lock(&cpuidle_lock); + + dev = per_cpu(cpuidle_devices, cpu); + if (dev && dev->coupled) + cpuidle_coupled_prevent_idle(dev->coupled); + + mutex_unlock(&cpuidle_lock); + return 0; +} static int __init cpuidle_coupled_init(void) { - return register_cpu_notifier(&cpuidle_coupled_cpu_notifier); + int ret; + + ret = cpuhp_setup_state_nocalls(CPUHP_CPUIDLE_COUPLED_PREPARE, + "CPUIDLE_COUPLED_PREPARE", + coupled_cpu_up_prepare, + coupled_cpu_online); + if (ret) + return ret; + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "CPUIDLE_COUPLED_ONLINE", + coupled_cpu_online, + coupled_cpu_up_prepare); + if (ret < 0) + cpuhp_remove_state_nocalls(CPUHP_CPUIDLE_COUPLED_PREPARE); + return ret; } core_initcall(cpuidle_coupled_init);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 14b58a9d1450..965acec06d4e 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h@@ -30,6 +30,7 @@ enum cpuhp_state { CPUHP_SLAB_PREPARE, CPUHP_RCUTREE_PREP, CPUHP_MD_RAID5_PREPARE, + CPUHP_CPUIDLE_COUPLED_PREPARE, CPUHP_NOTIFY_PREPARE, CPUHP_TIMERS_DEAD, CPUHP_BRINGUP_CPU,
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