ia64/linux-2.6.18-xen.hg

view arch/m68knommu/kernel/time.c @ 854:950b9eb27661

usbback: fix urb interval value for interrupt urbs.

Signed-off-by: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
author Keir Fraser <keir.fraser@citrix.com>
date Mon Apr 06 13:51:20 2009 +0100 (2009-04-06)
parents 831230e53067
children
line source
1 /*
2 * linux/arch/m68knommu/kernel/time.c
3 *
4 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
5 *
6 * This file contains the m68k-specific time handling details.
7 * Most of the stuff is located in the machine specific files.
8 *
9 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
10 * "A Kernel Model for Precision Timekeeping" by Dave Mills
11 */
13 #include <linux/errno.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/param.h>
18 #include <linux/string.h>
19 #include <linux/mm.h>
20 #include <linux/profile.h>
21 #include <linux/time.h>
22 #include <linux/timex.h>
24 #include <asm/machdep.h>
25 #include <asm/io.h>
27 #define TICK_SIZE (tick_nsec / 1000)
29 extern unsigned long wall_jiffies;
32 static inline int set_rtc_mmss(unsigned long nowtime)
33 {
34 if (mach_set_clock_mmss)
35 return mach_set_clock_mmss (nowtime);
36 return -1;
37 }
39 /*
40 * timer_interrupt() needs to keep up the real-time clock,
41 * as well as call the "do_timer()" routine every clocktick
42 */
43 static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
44 {
45 /* last time the cmos clock got updated */
46 static long last_rtc_update=0;
48 /* may need to kick the hardware timer */
49 if (mach_tick)
50 mach_tick();
52 write_seqlock(&xtime_lock);
54 do_timer(regs);
55 #ifndef CONFIG_SMP
56 update_process_times(user_mode(regs));
57 #endif
58 if (current->pid)
59 profile_tick(CPU_PROFILING, regs);
61 /*
62 * If we have an externally synchronized Linux clock, then update
63 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
64 * called as close as possible to 500 ms before the new second starts.
65 */
66 if (ntp_synced() &&
67 xtime.tv_sec > last_rtc_update + 660 &&
68 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
69 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
70 if (set_rtc_mmss(xtime.tv_sec) == 0)
71 last_rtc_update = xtime.tv_sec;
72 else
73 last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
74 }
75 #ifdef CONFIG_HEARTBEAT
76 /* use power LED as a heartbeat instead -- much more useful
77 for debugging -- based on the version for PReP by Cort */
78 /* acts like an actual heart beat -- ie thump-thump-pause... */
79 if (mach_heartbeat) {
80 static unsigned cnt = 0, period = 0, dist = 0;
82 if (cnt == 0 || cnt == dist)
83 mach_heartbeat( 1 );
84 else if (cnt == 7 || cnt == dist+7)
85 mach_heartbeat( 0 );
87 if (++cnt > period) {
88 cnt = 0;
89 /* The hyperbolic function below modifies the heartbeat period
90 * length in dependency of the current (5min) load. It goes
91 * through the points f(0)=126, f(1)=86, f(5)=51,
92 * f(inf)->30. */
93 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
94 dist = period / 4;
95 }
96 }
97 #endif /* CONFIG_HEARTBEAT */
99 write_sequnlock(&xtime_lock);
100 return(IRQ_HANDLED);
101 }
103 void time_init(void)
104 {
105 unsigned int year, mon, day, hour, min, sec;
107 extern void arch_gettod(int *year, int *mon, int *day, int *hour,
108 int *min, int *sec);
110 arch_gettod(&year, &mon, &day, &hour, &min, &sec);
112 if ((year += 1900) < 1970)
113 year += 100;
114 xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
115 xtime.tv_nsec = 0;
116 wall_to_monotonic.tv_sec = -xtime.tv_sec;
118 mach_sched_init(timer_interrupt);
119 }
121 /*
122 * This version of gettimeofday has near microsecond resolution.
123 */
124 void do_gettimeofday(struct timeval *tv)
125 {
126 unsigned long flags;
127 unsigned long lost, seq;
128 unsigned long usec, sec;
130 do {
131 seq = read_seqbegin_irqsave(&xtime_lock, flags);
132 usec = mach_gettimeoffset ? mach_gettimeoffset() : 0;
133 lost = jiffies - wall_jiffies;
134 if (lost)
135 usec += lost * (1000000 / HZ);
136 sec = xtime.tv_sec;
137 usec += (xtime.tv_nsec / 1000);
138 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
140 while (usec >= 1000000) {
141 usec -= 1000000;
142 sec++;
143 }
145 tv->tv_sec = sec;
146 tv->tv_usec = usec;
147 }
149 EXPORT_SYMBOL(do_gettimeofday);
151 int do_settimeofday(struct timespec *tv)
152 {
153 time_t wtm_sec, sec = tv->tv_sec;
154 long wtm_nsec, nsec = tv->tv_nsec;
156 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
157 return -EINVAL;
159 write_seqlock_irq(&xtime_lock);
160 /*
161 * This is revolting. We need to set the xtime.tv_usec
162 * correctly. However, the value in this location is
163 * is value at the last tick.
164 * Discover what correction gettimeofday
165 * would have done, and then undo it!
166 */
167 if (mach_gettimeoffset)
168 nsec -= (mach_gettimeoffset() * 1000);
170 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
171 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
173 set_normalized_timespec(&xtime, sec, nsec);
174 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
176 ntp_clear();
177 write_sequnlock_irq(&xtime_lock);
178 clock_was_set();
179 return 0;
180 }
182 /*
183 * Scheduler clock - returns current time in nanosec units.
184 */
185 unsigned long long sched_clock(void)
186 {
187 return (unsigned long long)jiffies * (1000000000 / HZ);
188 }
190 EXPORT_SYMBOL(do_settimeofday);