1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
/*
* linux/arch/h8300/kernel/time.c
*
* Yoshinori Sato <ysato@users.sourceforge.jp>
*
* Copied/hacked from:
*
* linux/arch/m68k/kernel/time.c
*
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
*
* This file contains the m68k-specific time handling details.
* Most of the stuff is located in the machine specific files.
*
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
* "A Kernel Model for Precision Timekeeping" by Dave Mills
*/
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/timex.h>
#include <linux/profile.h>
#include <asm/io.h>
#include <asm/target_time.h>
#define TICK_SIZE (tick_nsec / 1000)
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
static void timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
{
/* may need to kick the hardware timer */
platform_timer_eoi();
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
profile_tick(CPU_PROFILING, regs);
}
void time_init(void)
{
unsigned int year, mon, day, hour, min, 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;
platform_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;
platform_timer_setup(timer_interrupt);
}
/*
* This version of gettimeofday has near microsecond resolution.
*/
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
usec = 0;
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
read_unlock_irqrestore(&xtime_lock, flags);
while (usec >= 1000000) {
usec -= 1000000;
sec++;
}
tv->tv_sec = sec;
tv->tv_usec = usec;
}
EXPORT_SYMBOL(do_gettimeofday);
int do_settimeofday(struct timespec *tv)
{
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_lock_irq(&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec
* correctly. However, the value in this location is
* is value at the last tick.
* Discover what correction gettimeofday
* would have done, and then undo it!
*/
while (tv->tv_nsec < 0) {
tv->tv_nsec += NSEC_PER_SEC;
tv->tv_sec--;
}
xtime.tv_sec = tv->tv_sec;
xtime.tv_nsec = tv->tv_nsec;
ntp_clear();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
return 0;
}
EXPORT_SYMBOL(do_settimeofday);
|
