mirror of https://gitee.com/openkylin/linux.git
153 lines
3.0 KiB
C
153 lines
3.0 KiB
C
/*
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* linux/arch/arm/kernel/time.c
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*
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* Copyright (C) 1991, 1992, 1995 Linus Torvalds
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* Modifications for ARM (C) 1994-2001 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This file contains the ARM-specific time handling details:
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* reading the RTC at bootup, etc...
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*/
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#include <linux/export.h>
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#include <linux/kernel.h>
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <linux/timex.h>
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#include <linux/errno.h>
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#include <linux/profile.h>
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#include <linux/syscore_ops.h>
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#include <linux/timer.h>
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#include <linux/irq.h>
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#include <asm/leds.h>
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#include <asm/thread_info.h>
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#include <asm/sched_clock.h>
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#include <asm/stacktrace.h>
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#include <asm/mach/arch.h>
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#include <asm/mach/time.h>
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/*
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* Our system timer.
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*/
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static struct sys_timer *system_timer;
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#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
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defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
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/* this needs a better home */
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DEFINE_SPINLOCK(rtc_lock);
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EXPORT_SYMBOL(rtc_lock);
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#endif /* pc-style 'CMOS' RTC support */
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/* change this if you have some constant time drift */
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#define USECS_PER_JIFFY (1000000/HZ)
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#ifdef CONFIG_SMP
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unsigned long profile_pc(struct pt_regs *regs)
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{
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struct stackframe frame;
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if (!in_lock_functions(regs->ARM_pc))
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return regs->ARM_pc;
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frame.fp = regs->ARM_fp;
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frame.sp = regs->ARM_sp;
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frame.lr = regs->ARM_lr;
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frame.pc = regs->ARM_pc;
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do {
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int ret = unwind_frame(&frame);
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if (ret < 0)
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return 0;
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} while (in_lock_functions(frame.pc));
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return frame.pc;
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}
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EXPORT_SYMBOL(profile_pc);
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#endif
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#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
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u32 arch_gettimeoffset(void)
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{
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if (system_timer->offset != NULL)
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return system_timer->offset() * 1000;
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return 0;
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}
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#endif /* CONFIG_ARCH_USES_GETTIMEOFFSET */
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#ifdef CONFIG_LEDS_TIMER
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static inline void do_leds(void)
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{
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static unsigned int count = HZ/2;
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if (--count == 0) {
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count = HZ/2;
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leds_event(led_timer);
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}
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}
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#else
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#define do_leds()
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#endif
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#ifndef CONFIG_GENERIC_CLOCKEVENTS
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/*
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* Kernel system timer support.
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*/
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void timer_tick(void)
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{
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profile_tick(CPU_PROFILING);
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do_leds();
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xtime_update(1);
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#ifndef CONFIG_SMP
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update_process_times(user_mode(get_irq_regs()));
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#endif
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}
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#endif
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#if defined(CONFIG_PM) && !defined(CONFIG_GENERIC_CLOCKEVENTS)
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static int timer_suspend(void)
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{
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if (system_timer->suspend)
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system_timer->suspend();
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return 0;
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}
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static void timer_resume(void)
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{
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if (system_timer->resume)
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system_timer->resume();
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}
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#else
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#define timer_suspend NULL
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#define timer_resume NULL
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#endif
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static struct syscore_ops timer_syscore_ops = {
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.suspend = timer_suspend,
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.resume = timer_resume,
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};
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static int __init timer_init_syscore_ops(void)
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{
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register_syscore_ops(&timer_syscore_ops);
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return 0;
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}
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device_initcall(timer_init_syscore_ops);
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void __init time_init(void)
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{
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system_timer = machine_desc->timer;
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system_timer->init();
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sched_clock_postinit();
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}
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