linux-kernel-test/arch/arm/kernel/time.c
Linus Torvalds 0cd61b68c3 Initial blind fixup for arm for irq changes
Untested, but this should fix up the bulk of the totally mechanical
issues, and should make the actual detail fixing easier.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-06 10:59:54 -07:00

512 lines
11 KiB
C

/*
* linux/arch/arm/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
* Modifications for ARM (C) 1994-2001 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This file contains the ARM-specific time handling details:
* reading the RTC at bootup, etc...
*
* 1994-07-02 Alan Modra
* fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime
* 1998-12-20 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/timex.h>
#include <linux/errno.h>
#include <linux/profile.h>
#include <linux/sysdev.h>
#include <linux/timer.h>
#include <asm/leds.h>
#include <asm/thread_info.h>
#include <asm/mach/time.h>
/*
* Our system timer.
*/
struct sys_timer *system_timer;
/* this needs a better home */
DEFINE_SPINLOCK(rtc_lock);
#ifdef CONFIG_SA1100_RTC_MODULE
EXPORT_SYMBOL(rtc_lock);
#endif
/* change this if you have some constant time drift */
#define USECS_PER_JIFFY (1000000/HZ)
#ifdef CONFIG_SMP
unsigned long profile_pc(struct pt_regs *regs)
{
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);
#ifndef CONFIG_GENERIC_TIME
static unsigned long dummy_gettimeoffset(void)
{
return 0;
}
#endif
/*
* Scheduler clock - returns current time in nanosec units.
* This is the default implementation. Sub-architecture
* implementations can override this.
*/
unsigned long long __attribute__((weak)) sched_clock(void)
{
return (unsigned long long)jiffies * (1000000000 / HZ);
}
static unsigned long next_rtc_update;
/*
* If we have an externally synchronized linux clock, then update
* CMOS clock accordingly every ~11 minutes. set_rtc() has to be
* called as close as possible to 500 ms before the new second
* starts.
*/
static inline void do_set_rtc(void)
{
if (!ntp_synced() || set_rtc == NULL)
return;
if (next_rtc_update &&
time_before((unsigned long)xtime.tv_sec, next_rtc_update))
return;
if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) &&
xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1))
return;
if (set_rtc())
/*
* rtc update failed. Try again in 60s
*/
next_rtc_update = xtime.tv_sec + 60;
else
next_rtc_update = xtime.tv_sec + 660;
}
#ifdef CONFIG_LEDS
static void dummy_leds_event(led_event_t evt)
{
}
void (*leds_event)(led_event_t) = dummy_leds_event;
struct leds_evt_name {
const char name[8];
int on;
int off;
};
static const struct leds_evt_name evt_names[] = {
{ "amber", led_amber_on, led_amber_off },
{ "blue", led_blue_on, led_blue_off },
{ "green", led_green_on, led_green_off },
{ "red", led_red_on, led_red_off },
};
static ssize_t leds_store(struct sys_device *dev, const char *buf, size_t size)
{
int ret = -EINVAL, len = strcspn(buf, " ");
if (len > 0 && buf[len] == '\0')
len--;
if (strncmp(buf, "claim", len) == 0) {
leds_event(led_claim);
ret = size;
} else if (strncmp(buf, "release", len) == 0) {
leds_event(led_release);
ret = size;
} else {
int i;
for (i = 0; i < ARRAY_SIZE(evt_names); i++) {
if (strlen(evt_names[i].name) != len ||
strncmp(buf, evt_names[i].name, len) != 0)
continue;
if (strncmp(buf+len, " on", 3) == 0) {
leds_event(evt_names[i].on);
ret = size;
} else if (strncmp(buf+len, " off", 4) == 0) {
leds_event(evt_names[i].off);
ret = size;
}
break;
}
}
return ret;
}
static SYSDEV_ATTR(event, 0200, NULL, leds_store);
static int leds_suspend(struct sys_device *dev, pm_message_t state)
{
leds_event(led_stop);
return 0;
}
static int leds_resume(struct sys_device *dev)
{
leds_event(led_start);
return 0;
}
static int leds_shutdown(struct sys_device *dev)
{
leds_event(led_halted);
return 0;
}
static struct sysdev_class leds_sysclass = {
set_kset_name("leds"),
.shutdown = leds_shutdown,
.suspend = leds_suspend,
.resume = leds_resume,
};
static struct sys_device leds_device = {
.id = 0,
.cls = &leds_sysclass,
};
static int __init leds_init(void)
{
int ret;
ret = sysdev_class_register(&leds_sysclass);
if (ret == 0)
ret = sysdev_register(&leds_device);
if (ret == 0)
ret = sysdev_create_file(&leds_device, &attr_event);
return ret;
}
device_initcall(leds_init);
EXPORT_SYMBOL(leds_event);
#endif
#ifdef CONFIG_LEDS_TIMER
static inline void do_leds(void)
{
static unsigned int count = 50;
if (--count == 0) {
count = 50;
leds_event(led_timer);
}
}
#else
#define do_leds()
#endif
#ifndef CONFIG_GENERIC_TIME
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = system_timer->offset();
sec = xtime.tv_sec;
usec += xtime.tv_nsec / 1000;
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
/* usec may have gone up a lot: be safe */
while (usec >= 1000000) {
usec -= 1000000;
sec++;
}
tv->tv_sec = sec;
tv->tv_usec = usec;
}
EXPORT_SYMBOL(do_gettimeofday);
int do_settimeofday(struct timespec *tv)
{
time_t wtm_sec, sec = tv->tv_sec;
long wtm_nsec, nsec = tv->tv_nsec;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
* wall time. Discover what correction gettimeofday() would have
* done, and then undo it!
*/
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);
ntp_clear();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
#endif /* !CONFIG_GENERIC_TIME */
/**
* 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)
{
struct pt_regs *regs = get_irq_regs();
profile_tick(CPU_PROFILING, regs);
do_leds();
do_set_rtc();
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(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);
/*
* 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);
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
}