writeback: remove the internal 5% low bound on dirty_ratio
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / m68knommu / kernel / time.c
blobd6ac2a43453ce5be5808a0fa6aeacd4666cf8da6
1 /*
2 * linux/arch/m68knommu/kernel/time.c
4 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
6 * This file contains the m68k-specific time handling details.
7 * Most of the stuff is located in the machine specific files.
9 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
10 * "A Kernel Model for Precision Timekeeping" by Dave Mills
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/irq_regs.h>
27 #define TICK_SIZE (tick_nsec / 1000)
29 static inline int set_rtc_mmss(unsigned long nowtime)
31 if (mach_set_clock_mmss)
32 return mach_set_clock_mmss (nowtime);
33 return -1;
36 #ifndef CONFIG_GENERIC_CLOCKEVENTS
38 * timer_interrupt() needs to keep up the real-time clock,
39 * as well as call the "do_timer()" routine every clocktick
41 irqreturn_t arch_timer_interrupt(int irq, void *dummy)
44 if (current->pid)
45 profile_tick(CPU_PROFILING);
47 write_seqlock(&xtime_lock);
49 do_timer(1);
51 write_sequnlock(&xtime_lock);
53 update_process_times(user_mode(get_irq_regs()));
55 return(IRQ_HANDLED);
57 #endif
59 static unsigned long read_rtc_mmss(void)
61 unsigned int year, mon, day, hour, min, sec;
63 if (mach_gettod) {
64 mach_gettod(&year, &mon, &day, &hour, &min, &sec);
65 if ((year += 1900) < 1970)
66 year += 100;
67 } else {
68 year = 1970;
69 mon = day = 1;
70 hour = min = sec = 0;
74 return mktime(year, mon, day, hour, min, sec);
77 void read_persistent_clock(struct timespec *ts)
79 ts->tv_sec = read_rtc_mmss();
80 ts->tv_nsec = 0;
83 int update_persistent_clock(struct timespec now)
85 return set_rtc_mmss(now.tv_sec);
88 void time_init(void)
90 hw_timer_init();