![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
235 lines
6.2 KiB
C
235 lines
6.2 KiB
C
/* time.c: FRV arch-specific time handling
|
|
*
|
|
* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
* - Derived from arch/m68k/kernel/time.c
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/config.h> /* CONFIG_HEARTBEAT */
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/param.h>
|
|
#include <linux/string.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <asm/io.h>
|
|
#include <asm/timer-regs.h>
|
|
#include <asm/mb-regs.h>
|
|
#include <asm/mb86943a.h>
|
|
#include <asm/irq-routing.h>
|
|
|
|
#include <linux/timex.h>
|
|
|
|
#define TICK_SIZE (tick_nsec / 1000)
|
|
|
|
extern unsigned long wall_jiffies;
|
|
|
|
u64 jiffies_64 = INITIAL_JIFFIES;
|
|
EXPORT_SYMBOL(jiffies_64);
|
|
|
|
unsigned long __nongprelbss __clkin_clock_speed_HZ;
|
|
unsigned long __nongprelbss __ext_bus_clock_speed_HZ;
|
|
unsigned long __nongprelbss __res_bus_clock_speed_HZ;
|
|
unsigned long __nongprelbss __sdram_clock_speed_HZ;
|
|
unsigned long __nongprelbss __core_bus_clock_speed_HZ;
|
|
unsigned long __nongprelbss __core_clock_speed_HZ;
|
|
unsigned long __nongprelbss __dsu_clock_speed_HZ;
|
|
unsigned long __nongprelbss __serial_clock_speed_HZ;
|
|
unsigned long __delay_loops_MHz;
|
|
|
|
static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs *regs);
|
|
|
|
static struct irqaction timer_irq = {
|
|
timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, "timer", NULL, NULL
|
|
};
|
|
|
|
static inline int set_rtc_mmss(unsigned long nowtime)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* timer_interrupt() needs to keep up the real-time clock,
|
|
* as well as call the "do_timer()" routine every clocktick
|
|
*/
|
|
static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
|
|
{
|
|
/* last time the cmos clock got updated */
|
|
static long last_rtc_update = 0;
|
|
|
|
/*
|
|
* Here we are in the timer irq handler. We just have irqs locally
|
|
* disabled but we don't know if the timer_bh is running on the other
|
|
* CPU. We need to avoid to SMP race with it. NOTE: we don' t need
|
|
* the irq version of write_lock because as just said we have irq
|
|
* locally disabled. -arca
|
|
*/
|
|
write_seqlock(&xtime_lock);
|
|
|
|
do_timer(regs);
|
|
update_process_times(user_mode(regs));
|
|
profile_tick(CPU_PROFILING, regs);
|
|
|
|
/*
|
|
* If we have an externally synchronized Linux clock, then update
|
|
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
|
|
* called as close as possible to 500 ms before the new second starts.
|
|
*/
|
|
if ((time_status & STA_UNSYNC) == 0 &&
|
|
xtime.tv_sec > last_rtc_update + 660 &&
|
|
(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
|
|
(xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2
|
|
) {
|
|
if (set_rtc_mmss(xtime.tv_sec) == 0)
|
|
last_rtc_update = xtime.tv_sec;
|
|
else
|
|
last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
|
|
}
|
|
|
|
#ifdef CONFIG_HEARTBEAT
|
|
static unsigned short n;
|
|
n++;
|
|
__set_LEDS(n);
|
|
#endif /* CONFIG_HEARTBEAT */
|
|
|
|
write_sequnlock(&xtime_lock);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
void time_divisor_init(void)
|
|
{
|
|
unsigned short base, pre, prediv;
|
|
|
|
/* set the scheduling timer going */
|
|
pre = 1;
|
|
prediv = 4;
|
|
base = __res_bus_clock_speed_HZ / pre / HZ / (1 << prediv);
|
|
|
|
__set_TPRV(pre);
|
|
__set_TxCKSL_DATA(0, prediv);
|
|
__set_TCTR(TCTR_SC_CTR0 | TCTR_RL_RW_LH8 | TCTR_MODE_2);
|
|
__set_TCSR_DATA(0, base & 0xff);
|
|
__set_TCSR_DATA(0, base >> 8);
|
|
}
|
|
|
|
void time_init(void)
|
|
{
|
|
unsigned int year, mon, day, hour, min, sec;
|
|
|
|
extern void arch_gettod(int *year, int *mon, int *day, int *hour, int *min, int *sec);
|
|
|
|
/* FIX by dqg : Set to zero for platforms that don't have tod */
|
|
/* without this time is undefined and can overflow time_t, causing */
|
|
/* very stange errors */
|
|
year = 1980;
|
|
mon = day = 1;
|
|
hour = min = sec = 0;
|
|
arch_gettod (&year, &mon, &day, &hour, &min, &sec);
|
|
|
|
if ((year += 1900) < 1970)
|
|
year += 100;
|
|
xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
|
|
xtime.tv_nsec = 0;
|
|
|
|
/* install scheduling interrupt handler */
|
|
setup_irq(IRQ_CPU_TIMER0, &timer_irq);
|
|
|
|
time_divisor_init();
|
|
}
|
|
|
|
/*
|
|
* This version of gettimeofday has near microsecond resolution.
|
|
*/
|
|
void do_gettimeofday(struct timeval *tv)
|
|
{
|
|
unsigned long seq;
|
|
unsigned long usec, sec;
|
|
unsigned long max_ntp_tick;
|
|
|
|
do {
|
|
unsigned long lost;
|
|
|
|
seq = read_seqbegin(&xtime_lock);
|
|
|
|
usec = 0;
|
|
lost = jiffies - wall_jiffies;
|
|
|
|
/*
|
|
* If time_adjust is negative then NTP is slowing the clock
|
|
* so make sure not to go into next possible interval.
|
|
* Better to lose some accuracy than have time go backwards..
|
|
*/
|
|
if (unlikely(time_adjust < 0)) {
|
|
max_ntp_tick = (USEC_PER_SEC / HZ) - tickadj;
|
|
usec = min(usec, max_ntp_tick);
|
|
|
|
if (lost)
|
|
usec += lost * max_ntp_tick;
|
|
}
|
|
else if (unlikely(lost))
|
|
usec += lost * (USEC_PER_SEC / HZ);
|
|
|
|
sec = xtime.tv_sec;
|
|
usec += (xtime.tv_nsec / 1000);
|
|
} while (read_seqretry(&xtime_lock, seq));
|
|
|
|
while (usec >= 1000000) {
|
|
usec -= 1000000;
|
|
sec++;
|
|
}
|
|
|
|
tv->tv_sec = sec;
|
|
tv->tv_usec = usec;
|
|
}
|
|
|
|
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
|
|
* made, and then undo it!
|
|
*/
|
|
nsec -= 0 * NSEC_PER_USEC;
|
|
nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
|
|
|
|
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;
|
|
write_sequnlock_irq(&xtime_lock);
|
|
clock_was_set();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Scheduler clock - returns current time in nanosec units.
|
|
*/
|
|
unsigned long long sched_clock(void)
|
|
{
|
|
return jiffies_64 * (1000000000 / HZ);
|
|
}
|