121 строка
2.7 KiB
C
121 строка
2.7 KiB
C
/*
|
|
* linux/arch/arm/kernel/time.c
|
|
*
|
|
* Copyright (C) 1991, 1992, 1995 Linus Torvalds
|
|
* Modifications for ARM (C) 1994-2001 Russell King
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This file contains the ARM-specific time handling details:
|
|
* reading the RTC at bootup, etc...
|
|
*/
|
|
#include <linux/export.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/time.h>
|
|
#include <linux/init.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/timex.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/irq.h>
|
|
|
|
#include <asm/thread_info.h>
|
|
#include <asm/sched_clock.h>
|
|
#include <asm/stacktrace.h>
|
|
#include <asm/mach/arch.h>
|
|
#include <asm/mach/time.h>
|
|
|
|
#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
|
|
defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
|
|
/* this needs a better home */
|
|
DEFINE_SPINLOCK(rtc_lock);
|
|
EXPORT_SYMBOL(rtc_lock);
|
|
#endif /* pc-style 'CMOS' RTC support */
|
|
|
|
/* change this if you have some constant time drift */
|
|
#define USECS_PER_JIFFY (1000000/HZ)
|
|
|
|
#ifdef CONFIG_SMP
|
|
unsigned long profile_pc(struct pt_regs *regs)
|
|
{
|
|
struct stackframe frame;
|
|
|
|
if (!in_lock_functions(regs->ARM_pc))
|
|
return regs->ARM_pc;
|
|
|
|
frame.fp = regs->ARM_fp;
|
|
frame.sp = regs->ARM_sp;
|
|
frame.lr = regs->ARM_lr;
|
|
frame.pc = regs->ARM_pc;
|
|
do {
|
|
int ret = unwind_frame(&frame);
|
|
if (ret < 0)
|
|
return 0;
|
|
} while (in_lock_functions(frame.pc));
|
|
|
|
return frame.pc;
|
|
}
|
|
EXPORT_SYMBOL(profile_pc);
|
|
#endif
|
|
|
|
#ifndef CONFIG_GENERIC_CLOCKEVENTS
|
|
/*
|
|
* Kernel system timer support.
|
|
*/
|
|
void timer_tick(void)
|
|
{
|
|
profile_tick(CPU_PROFILING);
|
|
xtime_update(1);
|
|
#ifndef CONFIG_SMP
|
|
update_process_times(user_mode(get_irq_regs()));
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
static void dummy_clock_access(struct timespec *ts)
|
|
{
|
|
ts->tv_sec = 0;
|
|
ts->tv_nsec = 0;
|
|
}
|
|
|
|
static clock_access_fn __read_persistent_clock = dummy_clock_access;
|
|
static clock_access_fn __read_boot_clock = dummy_clock_access;;
|
|
|
|
void read_persistent_clock(struct timespec *ts)
|
|
{
|
|
__read_persistent_clock(ts);
|
|
}
|
|
|
|
void read_boot_clock(struct timespec *ts)
|
|
{
|
|
__read_boot_clock(ts);
|
|
}
|
|
|
|
int __init register_persistent_clock(clock_access_fn read_boot,
|
|
clock_access_fn read_persistent)
|
|
{
|
|
/* Only allow the clockaccess functions to be registered once */
|
|
if (__read_persistent_clock == dummy_clock_access &&
|
|
__read_boot_clock == dummy_clock_access) {
|
|
if (read_boot)
|
|
__read_boot_clock = read_boot;
|
|
if (read_persistent)
|
|
__read_persistent_clock = read_persistent;
|
|
|
|
return 0;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
void __init time_init(void)
|
|
{
|
|
machine_desc->init_time();
|
|
sched_clock_postinit();
|
|
}
|