ia64/linux-2.6.18-xen.hg

view arch/v850/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/v850/kernel/time.c -- Arch-dependent timer functions
3 *
4 * Copyright (C) 1991, 1992, 1995, 2001, 2002 Linus Torvalds
5 *
6 * This file contains the v850-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/config.h> /* CONFIG_HEARTBEAT */
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/param.h>
18 #include <linux/string.h>
19 #include <linux/mm.h>
20 #include <linux/interrupt.h>
21 #include <linux/time.h>
22 #include <linux/timex.h>
23 #include <linux/profile.h>
25 #include <asm/io.h>
27 #include "mach.h"
29 #define TICK_SIZE (tick_nsec / 1000)
31 /*
32 * Scheduler clock - returns current time in nanosec units.
33 */
34 unsigned long long sched_clock(void)
35 {
36 return (unsigned long long)jiffies * (1000000000 / HZ);
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 #if 0
46 /* last time the cmos clock got updated */
47 static long last_rtc_update=0;
48 #endif
50 /* may need to kick the hardware timer */
51 if (mach_tick)
52 mach_tick ();
54 do_timer (regs);
55 #ifndef CONFIG_SMP
56 update_process_times(user_mode(regs));
57 #endif
58 profile_tick(CPU_PROFILING, regs);
59 #if 0
60 /*
61 * If we have an externally synchronized Linux clock, then update
62 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
63 * called as close as possible to 500 ms before the new second starts.
64 */
65 if (ntp_synced() &&
66 xtime.tv_sec > last_rtc_update + 660 &&
67 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
68 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
69 if (set_rtc_mmss (xtime.tv_sec) == 0)
70 last_rtc_update = xtime.tv_sec;
71 else
72 last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
73 }
74 #ifdef CONFIG_HEARTBEAT
75 /* use power LED as a heartbeat instead -- much more useful
76 for debugging -- based on the version for PReP by Cort */
77 /* acts like an actual heart beat -- ie thump-thump-pause... */
78 if (mach_heartbeat) {
79 static unsigned cnt = 0, period = 0, dist = 0;
81 if (cnt == 0 || cnt == dist)
82 mach_heartbeat ( 1 );
83 else if (cnt == 7 || cnt == dist+7)
84 mach_heartbeat ( 0 );
86 if (++cnt > period) {
87 cnt = 0;
88 /* The hyperbolic function below modifies the heartbeat period
89 * length in dependency of the current (5min) load. It goes
90 * through the points f(0)=126, f(1)=86, f(5)=51,
91 * f(inf)->30. */
92 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
93 dist = period / 4;
94 }
95 }
96 #endif /* CONFIG_HEARTBEAT */
97 #endif /* 0 */
99 return IRQ_HANDLED;
100 }
102 /*
103 * This version of gettimeofday has near microsecond resolution.
104 */
105 void do_gettimeofday (struct timeval *tv)
106 {
107 #if 0 /* DAVIDM later if possible */
108 extern volatile unsigned long lost_ticks;
109 unsigned long lost;
110 #endif
111 unsigned long flags;
112 unsigned long usec, sec;
113 unsigned long seq;
115 do {
116 seq = read_seqbegin_irqsave(&xtime_lock, flags);
118 #if 0
119 usec = mach_gettimeoffset ? mach_gettimeoffset () : 0;
120 #else
121 usec = 0;
122 #endif
123 #if 0 /* DAVIDM later if possible */
124 lost = lost_ticks;
125 if (lost)
126 usec += lost * (1000000/HZ);
127 #endif
128 sec = xtime.tv_sec;
129 usec += xtime.tv_nsec / 1000;
130 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
132 while (usec >= 1000000) {
133 usec -= 1000000;
134 sec++;
135 }
137 tv->tv_sec = sec;
138 tv->tv_usec = usec;
139 }
141 EXPORT_SYMBOL(do_gettimeofday);
143 int do_settimeofday(struct timespec *tv)
144 {
145 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
146 return -EINVAL;
148 write_seqlock_irq (&xtime_lock);
150 /* This is revolting. We need to set the xtime.tv_nsec
151 * correctly. However, the value in this location is
152 * is value at the last tick.
153 * Discover what correction gettimeofday
154 * would have done, and then undo it!
155 */
156 #if 0
157 tv->tv_nsec -= mach_gettimeoffset() * 1000;
158 #endif
160 while (tv->tv_nsec < 0) {
161 tv->tv_nsec += NSEC_PER_SEC;
162 tv->tv_sec--;
163 }
165 xtime.tv_sec = tv->tv_sec;
166 xtime.tv_nsec = tv->tv_nsec;
168 ntp_clear();
170 write_sequnlock_irq (&xtime_lock);
171 clock_was_set();
172 return 0;
173 }
175 EXPORT_SYMBOL(do_settimeofday);
177 static int timer_dev_id;
178 static struct irqaction timer_irqaction = {
179 timer_interrupt,
180 IRQF_DISABLED,
181 CPU_MASK_NONE,
182 "timer",
183 &timer_dev_id,
184 NULL
185 };
187 void time_init (void)
188 {
189 mach_gettimeofday (&xtime);
190 mach_sched_init (&timer_irqaction);
191 }