-#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) {
- write_seqlock_irqsave(&xtime_lock, flags);
- ret = 0;
- if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
- ret = dyn_tick->enable();
-
- if (ret == 0)
- dyn_tick->state |= DYN_TICK_ENABLED;
- }
- write_sequnlock_irqrestore(&xtime_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) {
- write_seqlock_irqsave(&xtime_lock, flags);
- ret = 0;
- if (dyn_tick->state & DYN_TICK_ENABLED) {
- ret = dyn_tick->disable();
-
- if (ret == 0)
- dyn_tick->state &= ~DYN_TICK_ENABLED;
- }
- write_sequnlock_irqrestore(&xtime_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;
-
- if (dyn_tick) {
- write_seqlock(&xtime_lock);
- if (dyn_tick->state & DYN_TICK_ENABLED)
- dyn_tick->reprogram(next_timer_interrupt() - jiffies);
- write_sequnlock(&xtime_lock);
- }
-}
-
-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
-