diff options
Diffstat (limited to 'arch/arm/kernel/time.c')
| -rw-r--r-- | arch/arm/kernel/time.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index c232f24f4a60..06054c9ba074 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -381,6 +381,95 @@ 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) { + 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; +} + +void timer_dyn_reprogram(void) +{ + struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; + unsigned long flags; + + write_seqlock_irqsave(&xtime_lock, flags); + if (dyn_tick->state & DYN_TICK_ENABLED) + dyn_tick->reprogram(next_timer_interrupt() - jiffies); + write_sequnlock_irqrestore(&xtime_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); @@ -388,6 +477,20 @@ static int __init timer_init_sysfs(void) system_timer->dev.cls = &timer_sysclass; 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; } |