[ARM] dyntick: Remove obsolete and unused ARM dyntick support

dyntick is superseded by the clocksource/clockevent infrastructure,
using the NO_HZ configuration option.  No one implements dyntick on
ARM anymore, so it's pointless keeping it around.  Remove dyntick
support.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 1 insertions, 123 deletions

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 46bf2ede612..199b3680118 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -133,10 +133,8 @@ static void default_idle(void)
 		cpu_relax();
 	else {
 		local_irq_disable();
-		if (!need_resched()) {
-			timer_dyn_reprogram();
+		if (!need_resched())
 			arch_idle();
-		}
 		local_irq_enable();
 	}
 }
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index b5867eca1d0..cc5145b28e7 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -365,108 +365,6 @@ static struct sysdev_class timer_sysclass = {
 	.resume		= timer_resume,
 };
 
-#ifdef CONFIG_NO_IDLE_HZ
-static int timer_dyn_tick_enable(void)
-{
-	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
-	unsigned long flags;
-	int ret = -ENODEV;
-
-	if (dyn_tick) {
-		spin_lock_irqsave(&dyn_tick->lock, flags);
-		ret = 0;
-		if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
-			ret = dyn_tick->enable();
-
-			if (ret == 0)
-				dyn_tick->state |= DYN_TICK_ENABLED;
-		}
-		spin_unlock_irqrestore(&dyn_tick->lock, flags);
-	}
-
-	return ret;
-}
-
-static int timer_dyn_tick_disable(void)
-{
-	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
-	unsigned long flags;
-	int ret = -ENODEV;
-
-	if (dyn_tick) {
-		spin_lock_irqsave(&dyn_tick->lock, flags);
-		ret = 0;
-		if (dyn_tick->state & DYN_TICK_ENABLED) {
-			ret = dyn_tick->disable();
-
-			if (ret == 0)
-				dyn_tick->state &= ~DYN_TICK_ENABLED;
-		}
-		spin_unlock_irqrestore(&dyn_tick->lock, flags);
-	}
-
-	return ret;
-}
-
-/*
- * Reprogram the system timer for at least the calculated time interval.
- * This function should be called from the idle thread with IRQs disabled,
- * immediately before sleeping.
- */
-void timer_dyn_reprogram(void)
-{
-	struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
-	unsigned long next, seq, flags;
-
-	if (!dyn_tick)
-		return;
-
-	spin_lock_irqsave(&dyn_tick->lock, flags);
-	if (dyn_tick->state & DYN_TICK_ENABLED) {
-		next = next_timer_interrupt();
-		do {
-			seq = read_seqbegin(&xtime_lock);
-			dyn_tick->reprogram(next - jiffies);
-		} while (read_seqretry(&xtime_lock, seq));
-	}
-	spin_unlock_irqrestore(&dyn_tick->lock, flags);
-}
-
-static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf)
-{
-	return sprintf(buf, "%i\n",
-		       (system_timer->dyn_tick->state & DYN_TICK_ENABLED) >> 1);
-}
-
-static ssize_t timer_set_dyn_tick(struct sys_device *dev, const char *buf,
-				  size_t count)
-{
-	unsigned int enable = simple_strtoul(buf, NULL, 2);
-
-	if (enable)
-		timer_dyn_tick_enable();
-	else
-		timer_dyn_tick_disable();
-
-	return count;
-}
-static SYSDEV_ATTR(dyn_tick, 0644, timer_show_dyn_tick, timer_set_dyn_tick);
-
-/*
- * dyntick=enable|disable
- */
-static char dyntick_str[4] __initdata = "";
-
-static int __init dyntick_setup(char *str)
-{
-	if (str)
-		strlcpy(dyntick_str, str, sizeof(dyntick_str));
-	return 1;
-}
-
-__setup("dyntick=", dyntick_setup);
-#endif
-
 static int __init timer_init_sysfs(void)
 {
 	int ret = sysdev_class_register(&timer_sysclass);
@@ -475,19 +373,6 @@ static int __init timer_init_sysfs(void)
 		ret = sysdev_register(&system_timer->dev);
 	}
 
-#ifdef CONFIG_NO_IDLE_HZ
-	if (ret == 0 && system_timer->dyn_tick) {
-		ret = sysdev_create_file(&system_timer->dev, &attr_dyn_tick);
-
-		/*
-		 * Turn on dynamic tick after calibrate delay
-		 * for correct bogomips
-		 */
-		if (ret == 0 && dyntick_str[0] == 'e')
-			ret = timer_dyn_tick_enable();
-	}
-#endif
-
 	return ret;
 }
 
@@ -500,10 +385,5 @@ void __init time_init(void)
 		system_timer->offset = dummy_gettimeoffset;
 #endif
 	system_timer->init();
-
-#ifdef CONFIG_NO_IDLE_HZ
-	if (system_timer->dyn_tick)
-		spin_lock_init(&system_timer->dyn_tick->lock);
-#endif
 }