ia64/linux-2.6.18-xen.hg

view arch/m68k/kernel/time.c @ 452:c7ed6fe5dca0

kexec: dont initialise regions in reserve_memory()

There is no need to initialise efi_memmap_res and boot_param_res in
reserve_memory() for the initial xen domain as it is done in
machine_kexec_setup_resources() using values from the kexec hypercall.

Signed-off-by: Simon Horman <horms@verge.net.au>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Feb 28 10:55:18 2008 +0000 (2008-02-28)
parents 831230e53067
children
line source
1 /*
2 * linux/arch/m68k/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/config.h> /* CONFIG_HEARTBEAT */
14 #include <linux/errno.h>
15 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/param.h>
19 #include <linux/string.h>
20 #include <linux/mm.h>
21 #include <linux/rtc.h>
23 #include <asm/machdep.h>
24 #include <asm/io.h>
26 #include <linux/time.h>
27 #include <linux/timex.h>
28 #include <linux/profile.h>
30 static inline int set_rtc_mmss(unsigned long nowtime)
31 {
32 if (mach_set_clock_mmss)
33 return mach_set_clock_mmss (nowtime);
34 return -1;
35 }
37 /*
38 * timer_interrupt() needs to keep up the real-time clock,
39 * as well as call the "do_timer()" routine every clocktick
40 */
41 static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
42 {
43 do_timer(regs);
44 #ifndef CONFIG_SMP
45 update_process_times(user_mode(regs));
46 #endif
47 profile_tick(CPU_PROFILING, regs);
49 #ifdef CONFIG_HEARTBEAT
50 /* use power LED as a heartbeat instead -- much more useful
51 for debugging -- based on the version for PReP by Cort */
52 /* acts like an actual heart beat -- ie thump-thump-pause... */
53 if (mach_heartbeat) {
54 static unsigned cnt = 0, period = 0, dist = 0;
56 if (cnt == 0 || cnt == dist)
57 mach_heartbeat( 1 );
58 else if (cnt == 7 || cnt == dist+7)
59 mach_heartbeat( 0 );
61 if (++cnt > period) {
62 cnt = 0;
63 /* The hyperbolic function below modifies the heartbeat period
64 * length in dependency of the current (5min) load. It goes
65 * through the points f(0)=126, f(1)=86, f(5)=51,
66 * f(inf)->30. */
67 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
68 dist = period / 4;
69 }
70 }
71 #endif /* CONFIG_HEARTBEAT */
72 return IRQ_HANDLED;
73 }
75 void time_init(void)
76 {
77 struct rtc_time time;
79 if (mach_hwclk) {
80 mach_hwclk(0, &time);
82 if ((time.tm_year += 1900) < 1970)
83 time.tm_year += 100;
84 xtime.tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
85 time.tm_hour, time.tm_min, time.tm_sec);
86 xtime.tv_nsec = 0;
87 }
88 wall_to_monotonic.tv_sec = -xtime.tv_sec;
90 mach_sched_init(timer_interrupt);
91 }
93 /*
94 * This version of gettimeofday has near microsecond resolution.
95 */
96 void do_gettimeofday(struct timeval *tv)
97 {
98 unsigned long flags;
99 extern unsigned long wall_jiffies;
100 unsigned long seq;
101 unsigned long usec, sec, lost;
102 unsigned long max_ntp_tick = tick_usec - tickadj;
104 do {
105 seq = read_seqbegin_irqsave(&xtime_lock, flags);
107 usec = mach_gettimeoffset();
108 lost = jiffies - wall_jiffies;
110 /*
111 * If time_adjust is negative then NTP is slowing the clock
112 * so make sure not to go into next possible interval.
113 * Better to lose some accuracy than have time go backwards..
114 */
115 if (unlikely(time_adjust < 0)) {
116 usec = min(usec, max_ntp_tick);
118 if (lost)
119 usec += lost * max_ntp_tick;
120 }
121 else if (unlikely(lost))
122 usec += lost * tick_usec;
124 sec = xtime.tv_sec;
125 usec += xtime.tv_nsec/1000;
126 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
129 while (usec >= 1000000) {
130 usec -= 1000000;
131 sec++;
132 }
134 tv->tv_sec = sec;
135 tv->tv_usec = usec;
136 }
138 EXPORT_SYMBOL(do_gettimeofday);
140 int do_settimeofday(struct timespec *tv)
141 {
142 time_t wtm_sec, sec = tv->tv_sec;
143 long wtm_nsec, nsec = tv->tv_nsec;
144 extern unsigned long wall_jiffies;
146 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
147 return -EINVAL;
149 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 nsec -= 1000 * (mach_gettimeoffset() +
157 (jiffies - wall_jiffies) * (1000000 / HZ));
159 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
160 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
162 set_normalized_timespec(&xtime, sec, nsec);
163 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
165 ntp_clear();
166 write_sequnlock_irq(&xtime_lock);
167 clock_was_set();
168 return 0;
169 }
171 EXPORT_SYMBOL(do_settimeofday);
173 /*
174 * Scheduler clock - returns current time in ns units.
175 */
176 unsigned long long sched_clock(void)
177 {
178 return (unsigned long long)jiffies*(1000000000/HZ);
179 }