diff options
| author | Richard Cochran <rcochran@linutronix.de> | 2016-07-13 19:17:04 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-07-15 10:41:44 +0200 |
| commit | b8a12296ac812f829bd9392346b01b1872d8118b (patch) | |
| tree | 17ece87e42778a15a9d033440a8dd74a9b24ba66 | |
| parent | rcu: Convert rcutree to hotplug state machine (diff) | |
| download | linux-b8a12296ac812f829bd9392346b01b1872d8118b.tar.xz linux-b8a12296ac812f829bd9392346b01b1872d8118b.zip | |
clocksource/arm_global_timer: Convert to hotplug state machine
Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel@stlinux.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153338.062741642@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | drivers/clocksource/arm_global_timer.c | 39 | ||||
| -rw-r--r-- | include/linux/cpuhotplug.h | 1 |
2 files changed, 11 insertions, 29 deletions
diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c index 2a9ceb6e93f9..8da03298f844 100644 --- a/drivers/clocksource/arm_global_timer.c +++ b/drivers/clocksource/arm_global_timer.c @@ -165,9 +165,9 @@ static irqreturn_t gt_clockevent_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -static int gt_clockevents_init(struct clock_event_device *clk) +static int gt_starting_cpu(unsigned int cpu) { - int cpu = smp_processor_id(); + struct clock_event_device *clk = this_cpu_ptr(gt_evt); clk->name = "arm_global_timer"; clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT | @@ -186,10 +186,13 @@ static int gt_clockevents_init(struct clock_event_device *clk) return 0; } -static void gt_clockevents_stop(struct clock_event_device *clk) +static int gt_dying_cpu(unsigned int cpu) { + struct clock_event_device *clk = this_cpu_ptr(gt_evt); + gt_clockevent_shutdown(clk); disable_percpu_irq(clk->irq); + return 0; } static cycle_t gt_clocksource_read(struct clocksource *cs) @@ -252,24 +255,6 @@ static int __init gt_clocksource_init(void) return clocksource_register_hz(>_clocksource, gt_clk_rate); } -static int gt_cpu_notify(struct notifier_block *self, unsigned long action, - void *hcpu) -{ - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_STARTING: - gt_clockevents_init(this_cpu_ptr(gt_evt)); - break; - case CPU_DYING: - gt_clockevents_stop(this_cpu_ptr(gt_evt)); - break; - } - - return NOTIFY_OK; -} -static struct notifier_block gt_cpu_nb = { - .notifier_call = gt_cpu_notify, -}; - static int __init global_timer_of_register(struct device_node *np) { struct clk *gt_clk; @@ -325,18 +310,14 @@ static int __init global_timer_of_register(struct device_node *np) goto out_free; } - err = register_cpu_notifier(>_cpu_nb); - if (err) { - pr_warn("global-timer: unable to register cpu notifier.\n"); - goto out_irq; - } - - /* Immediately configure the timer on the boot CPU */ + /* Register and immediately configure the timer on the boot CPU */ err = gt_clocksource_init(); if (err) goto out_irq; - err = gt_clockevents_init(this_cpu_ptr(gt_evt)); + err = cpuhp_setup_state(CPUHP_AP_ARM_GLOBAL_TIMER_STARTING, + "AP_ARM_GLOBAL_TIMER_STARTING", + gt_starting_cpu, gt_dying_cpu); if (err) goto out_irq; diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 201a2e23bc49..d24b0fc2f88d 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -47,6 +47,7 @@ enum cpuhp_state { CPUHP_AP_PERF_ARM_STARTING, CPUHP_AP_ARM_L2X0_STARTING, CPUHP_AP_ARM_ARCH_TIMER_STARTING, + CPUHP_AP_ARM_GLOBAL_TIMER_STARTING, CPUHP_AP_DUMMY_TIMER_STARTING, CPUHP_AP_ARM_TWD_STARTING, CPUHP_AP_METAG_TIMER_STARTING, |