[patch 51/66] arm: twd: Convert to hotplug state machine
From: Anna-Maria Gleixner <anna-maria@linutronix.de>
Date: 2016-07-11 12:36:14
Also in:
linux-arm-kernel
From: Richard Cochran <redacted> Install the callbacks via the state machine. The callbacks won't be invoked on already online CPUs. Signed-off-by: Richard Cochran <redacted> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Russell King <redacted> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> --- arch/arm/kernel/smp_twd.c | 31 +++++++++++-------------------- include/linux/cpuhotplug.h | 1 + 2 files changed, 12 insertions(+), 20 deletions(-)
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c@@ -310,24 +310,17 @@ static void twd_timer_setup(void) enable_percpu_irq(clk->irq, 0); } -static int twd_timer_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) +static int twd_timer_starting_cpu(unsigned int cpu) { - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_STARTING: - twd_timer_setup(); - break; - case CPU_DYING: - twd_timer_stop(); - break; - } - - return NOTIFY_OK; + twd_timer_setup(); + return 0; } -static struct notifier_block twd_timer_cpu_nb = { - .notifier_call = twd_timer_cpu_notify, -}; +static int twd_timer_dying_cpu(unsigned int cpu) +{ + twd_timer_stop(); + return 0; +} static int __init twd_local_timer_common_register(struct device_node *np) {
@@ -345,9 +338,9 @@ static int __init twd_local_timer_common goto out_free; } - err = register_cpu_notifier(&twd_timer_cpu_nb); - if (err) - goto out_irq; + cpuhp_setup_state_nocalls(CPUHP_AP_ARM_TWD_STARTING, + "AP_ARM_TWD_STARTING", + twd_timer_starting_cpu, twd_timer_dying_cpu); twd_get_clock(np); if (!of_property_read_bool(np, "always-on"))
@@ -365,8 +358,6 @@ static int __init twd_local_timer_common return 0; -out_irq: - free_percpu_irq(twd_ppi, twd_evt); out_free: iounmap(twd_base); twd_base = NULL; --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h
@@ -42,6 +42,7 @@ enum cpuhp_state { CPUHP_AP_ARM_ARCH_TIMER_STARTING, CPUHP_AP_ARM_GLOBAL_TIMER_STARTING, CPUHP_AP_DUMMY_TIMER_STARTING, + CPUHP_AP_ARM_TWD_STARTING, CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING, CPUHP_AP_METAG_TIMER_STARTING, CPUHP_AP_QCOM_TIMER_STARTING,