diff options
Diffstat (limited to 'arch/sh/kernel/time.c')
| -rw-r--r-- | arch/sh/kernel/time.c | 139 |
1 files changed, 134 insertions, 5 deletions
diff --git a/arch/sh/kernel/time.c b/arch/sh/kernel/time.c index 57e708d7b52..c206c9504c4 100644 --- a/arch/sh/kernel/time.c +++ b/arch/sh/kernel/time.c @@ -13,6 +13,8 @@ #include <linux/module.h> #include <linux/init.h> #include <linux/profile.h> +#include <linux/timex.h> +#include <linux/sched.h> #include <asm/clock.h> #include <asm/rtc.h> #include <asm/timer.h> @@ -50,15 +52,20 @@ unsigned long long __attribute__ ((weak)) sched_clock(void) #ifndef CONFIG_GENERIC_TIME void do_gettimeofday(struct timeval *tv) { + unsigned long flags; unsigned long seq; unsigned long usec, sec; do { - seq = read_seqbegin(&xtime_lock); + /* + * Turn off IRQs when grabbing xtime_lock, so that + * the sys_timer get_offset code doesn't have to handle it. + */ + seq = read_seqbegin_irqsave(&xtime_lock, flags); usec = get_timer_offset(); sec = xtime.tv_sec; - usec += xtime.tv_nsec / 1000; - } while (read_seqretry(&xtime_lock, seq)); + usec += xtime.tv_nsec / NSEC_PER_USEC; + } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); while (usec >= 1000000) { usec -= 1000000; @@ -85,7 +92,7 @@ int do_settimeofday(struct timespec *tv) * wall time. Discover what correction gettimeofday() would have * made, and then undo it! */ - nsec -= 1000 * get_timer_offset(); + nsec -= get_timer_offset() * NSEC_PER_USEC; wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); @@ -169,6 +176,108 @@ 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 = sys_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 = sys_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 = sys_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", + (sys_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); @@ -176,7 +285,22 @@ static int __init timer_init_sysfs(void) return ret; sys_timer->dev.cls = &timer_sysclass; - return sysdev_register(&sys_timer->dev); + ret = sysdev_register(&sys_timer->dev); + +#ifdef CONFIG_NO_IDLE_HZ + if (ret == 0 && sys_timer->dyn_tick) { + ret = sysdev_create_file(&sys_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; } device_initcall(timer_init_sysfs); @@ -200,6 +324,11 @@ void __init time_init(void) sys_timer = get_sys_timer(); printk(KERN_INFO "Using %s for system timer\n", sys_timer->name); +#ifdef CONFIG_NO_IDLE_HZ + if (sys_timer->dyn_tick) + spin_lock_init(&sys_timer->dyn_tick->lock); +#endif + #if defined(CONFIG_SH_KGDB) /* * Set up kgdb as requested. We do it here because the serial |