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authorRichard Cochran <rcochran@linutronix.de>2016-07-13 17:17:04 +0000
committerIngo Molnar <mingo@kernel.org>2016-07-15 10:41:44 +0200
commitb8a12296ac812f829bd9392346b01b1872d8118b (patch)
tree17ece87e42778a15a9d033440a8dd74a9b24ba66 /drivers/clocksource
parent4df8374254ea9294dfe4b8c447a1b7eddc543dbf (diff)
downloadlinux-b8a12296ac812f829bd9392346b01b1872d8118b.tar.bz2
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>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/arm_global_timer.c39
1 files changed, 10 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(&gt_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(&gt_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;