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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | /* time.c: FRV arch-specific time handling
*
* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* - Derived from arch/m68k/kernel/time.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/profile.h>
#include <linux/irq.h>
#include <linux/mm.h>
#include <asm/io.h>
#include <asm/timer-regs.h>
#include <asm/mb-regs.h>
#include <asm/mb86943a.h>
#include <linux/timex.h>
#define TICK_SIZE (tick_nsec / 1000)
unsigned long __nongprelbss __clkin_clock_speed_HZ;
unsigned long __nongprelbss __ext_bus_clock_speed_HZ;
unsigned long __nongprelbss __res_bus_clock_speed_HZ;
unsigned long __nongprelbss __sdram_clock_speed_HZ;
unsigned long __nongprelbss __core_bus_clock_speed_HZ;
unsigned long __nongprelbss __core_clock_speed_HZ;
unsigned long __nongprelbss __dsu_clock_speed_HZ;
unsigned long __nongprelbss __serial_clock_speed_HZ;
unsigned long __delay_loops_MHz;
static irqreturn_t timer_interrupt(int irq, void *dummy);
static struct irqaction timer_irq = {
.handler = timer_interrupt,
.flags = IRQF_DISABLED,
.name = "timer",
};
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
static irqreturn_t timer_interrupt(int irq, void *dummy)
{
profile_tick(CPU_PROFILING);
/*
* Here we are in the timer irq handler. We just have irqs locally
* disabled but we don't know if the timer_bh is running on the other
* CPU. We need to avoid to SMP race with it. NOTE: we don't need
* the irq version of write_lock because as just said we have irq
* locally disabled. -arca
*/
write_seqlock(&xtime_lock);
do_timer(1);
#ifdef CONFIG_HEARTBEAT
static unsigned short n;
n++;
__set_LEDS(n);
#endif /* CONFIG_HEARTBEAT */
write_sequnlock(&xtime_lock);
update_process_times(user_mode(get_irq_regs()));
return IRQ_HANDLED;
}
void time_divisor_init(void)
{
unsigned short base, pre, prediv;
/* set the scheduling timer going */
pre = 1;
prediv = 4;
base = __res_bus_clock_speed_HZ / pre / HZ / (1 << prediv);
__set_TPRV(pre);
__set_TxCKSL_DATA(0, prediv);
__set_TCTR(TCTR_SC_CTR0 | TCTR_RL_RW_LH8 | TCTR_MODE_2);
__set_TCSR_DATA(0, base & 0xff);
__set_TCSR_DATA(0, base >> 8);
}
void read_persistent_clock(struct timespec *ts)
{
unsigned int year, mon, day, hour, min, sec;
extern void arch_gettod(int *year, int *mon, int *day, int *hour, int *min, int *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 strange errors */
year = 1980;
mon = day = 1;
hour = min = sec = 0;
arch_gettod (&year, &mon, &day, &hour, &min, &sec);
if ((year += 1900) < 1970)
year += 100;
ts->tv_sec = mktime(year, mon, day, hour, min, sec);
ts->tv_nsec = 0;
}
void time_init(void)
{
/* install scheduling interrupt handler */
setup_irq(IRQ_CPU_TIMER0, &timer_irq);
time_divisor_init();
}
/*
* Scheduler clock - returns current time in nanosec units.
*/
unsigned long long sched_clock(void)
{
return jiffies_64 * (1000000000 / HZ);
}
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