* 1998-12-20 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/profile.h>
#include <linux/sysdev.h>
+#include <linux/timer.h>
+#include <linux/irq.h>
-#include <asm/hardware.h>
-#include <asm/io.h>
-#include <asm/irq.h>
-#include <asm/leds.h>
-
-u64 jiffies_64 = INITIAL_JIFFIES;
+#include <linux/mc146818rtc.h>
-EXPORT_SYMBOL(jiffies_64);
+#include <asm/leds.h>
+#include <asm/thread_info.h>
+#include <asm/mach/time.h>
-extern unsigned long wall_jiffies;
+/*
+ * Our system timer.
+ */
+struct sys_timer *system_timer;
/* this needs a better home */
-spinlock_t rtc_lock = SPIN_LOCK_UNLOCKED;
+DEFINE_SPINLOCK(rtc_lock);
#ifdef CONFIG_SA1100_RTC_MODULE
EXPORT_SYMBOL(rtc_lock);
/* change this if you have some constant time drift */
#define USECS_PER_JIFFY (1000000/HZ)
-static int dummy_set_rtc(void)
+#ifdef CONFIG_SMP
+unsigned long profile_pc(struct pt_regs *regs)
{
- return 0;
+ unsigned long fp, pc = instruction_pointer(regs);
+
+ if (in_lock_functions(pc)) {
+ fp = regs->ARM_fp;
+ pc = pc_pointer(((unsigned long *)fp)[-1]);
+ }
+
+ return pc;
}
+EXPORT_SYMBOL(profile_pc);
+#endif
/*
* hook for setting the RTC's idea of the current time.
*/
-int (*set_rtc)(void) = dummy_set_rtc;
+int (*set_rtc)(void);
+#ifndef CONFIG_GENERIC_TIME
static unsigned long dummy_gettimeoffset(void)
{
return 0;
}
-
-/*
- * hook for getting the time offset. Note that it is
- * always called with interrupts disabled.
- */
-unsigned long (*gettimeoffset)(void) = dummy_gettimeoffset;
+#endif
/*
* Scheduler clock - returns current time in nanosec units.
}
/*
- * Handle kernel profile stuff...
+ * An implementation of printk_clock() independent from
+ * sched_clock(). This avoids non-bootable kernels when
+ * printk_clock is enabled.
*/
-static inline void do_profile(struct pt_regs *regs)
+unsigned long long printk_clock(void)
{
-
- profile_hook(regs);
-
- if (!user_mode(regs) &&
- prof_buffer &&
- current->pid) {
- unsigned long pc = instruction_pointer(regs);
- extern int _stext;
-
- pc -= (unsigned long)&_stext;
-
- pc >>= prof_shift;
-
- if (pc >= prof_len)
- pc = prof_len - 1;
-
- prof_buffer[pc] += 1;
- }
+ return (unsigned long long)(jiffies - INITIAL_JIFFIES) *
+ (1000000000 / HZ);
}
static unsigned long next_rtc_update;
*/
static inline void do_set_rtc(void)
{
- if (time_status & STA_UNSYNC || set_rtc == NULL)
+ if (!ntp_synced() || set_rtc == NULL)
return;
if (next_rtc_update &&
static SYSDEV_ATTR(event, 0200, NULL, leds_store);
-static int leds_suspend(struct sys_device *dev, u32 state)
+static int leds_suspend(struct sys_device *dev, pm_message_t state)
{
leds_event(led_stop);
return 0;
#endif
#ifdef CONFIG_LEDS_TIMER
-static void do_leds(void)
+static inline void do_leds(void)
{
- static unsigned int count = 50;
+ static unsigned int count = HZ/2;
if (--count == 0) {
- count = 50;
+ count = HZ/2;
leds_event(led_timer);
}
}
#else
-#define do_leds()
+#define do_leds()
#endif
+#ifndef CONFIG_GENERIC_TIME
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
- unsigned long usec, sec, lost;
+ unsigned long usec, sec;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
- usec = gettimeoffset();
-
- lost = jiffies - wall_jiffies;
- if (lost)
- usec += lost * USECS_PER_JIFFY;
-
+ usec = system_timer->offset();
sec = xtime.tv_sec;
usec += xtime.tv_nsec / 1000;
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
* wall time. Discover what correction gettimeofday() would have
* done, and then undo it!
*/
- nsec -= gettimeoffset() * NSEC_PER_USEC;
- nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
+ nsec -= system_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);
set_normalized_timespec(&xtime, sec, nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
- time_adjust = 0; /* stop active adjtime() */
- time_status |= STA_UNSYNC;
- time_maxerror = NTP_PHASE_LIMIT;
- time_esterror = NTP_PHASE_LIMIT;
+ ntp_clear();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
+#endif /* !CONFIG_GENERIC_TIME */
-static struct irqaction timer_irq = {
- .name = "timer",
- .flags = SA_INTERRUPT,
+/**
+ * save_time_delta - Save the offset between system time and RTC time
+ * @delta: pointer to timespec to store delta
+ * @rtc: pointer to timespec for current RTC time
+ *
+ * Return a delta between the system time and the RTC time, such
+ * that system time can be restored later with restore_time_delta()
+ */
+void save_time_delta(struct timespec *delta, struct timespec *rtc)
+{
+ set_normalized_timespec(delta,
+ xtime.tv_sec - rtc->tv_sec,
+ xtime.tv_nsec - rtc->tv_nsec);
+}
+EXPORT_SYMBOL(save_time_delta);
+
+/**
+ * restore_time_delta - Restore the current system time
+ * @delta: delta returned by save_time_delta()
+ * @rtc: pointer to timespec for current RTC time
+ */
+void restore_time_delta(struct timespec *delta, struct timespec *rtc)
+{
+ struct timespec ts;
+
+ set_normalized_timespec(&ts,
+ delta->tv_sec + rtc->tv_sec,
+ delta->tv_nsec + rtc->tv_nsec);
+
+ do_settimeofday(&ts);
+}
+EXPORT_SYMBOL(restore_time_delta);
+
+/*
+ * Kernel system timer support.
+ */
+void timer_tick(void)
+{
+ profile_tick(CPU_PROFILING);
+ do_leds();
+ do_set_rtc();
+ do_timer(1);
+#ifndef CONFIG_SMP
+ update_process_times(user_mode(get_irq_regs()));
+#endif
+}
+
+#ifdef CONFIG_PM
+static int timer_suspend(struct sys_device *dev, pm_message_t state)
+{
+ struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
+
+ if (timer->suspend != NULL)
+ timer->suspend();
+
+ return 0;
+}
+
+static int timer_resume(struct sys_device *dev)
+{
+ struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
+
+ if (timer->resume != NULL)
+ timer->resume();
+
+ return 0;
+}
+#else
+#define timer_suspend NULL
+#define timer_resume NULL
+#endif
+
+static struct sysdev_class timer_sysclass = {
+ set_kset_name("timer"),
+ .suspend = timer_suspend,
+ .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);
+
/*
- * Include architecture specific code
+ * dyntick=enable|disable
*/
-#include <asm/arch/time.h>
+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);
+ if (ret == 0) {
+ 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;
+}
+
+device_initcall(timer_init_sysfs);
+
+void __init time_init(void)
+{
+#ifndef CONFIG_GENERIC_TIME
+ if (system_timer->offset == NULL)
+ system_timer->offset = dummy_gettimeoffset;
+#endif
+ system_timer->init();
+
+#ifdef CONFIG_NO_IDLE_HZ
+ if (system_timer->dyn_tick)
+ system_timer->dyn_tick->lock = SPIN_LOCK_UNLOCKED;
+#endif
+}
+
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