xtime_update takes the xtime_lock itself. Signed-off-by: Torben Hohn <torbenh@gmx.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: johnstul@us.ibm.com Cc: hch@infradead.org Cc: yong.zhang0@gmail.com LKML-Reference: <20110127145920.23248.75541.stgit@localhost> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
		
			
				
	
	
		
			169 lines
		
	
	
	
		
			3.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			169 lines
		
	
	
	
		
			3.4 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/module.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/sysdev.h>
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#include <linux/timer.h>
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#include <linux/irq.h>
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#include <linux/mc146818rtc.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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/* this needs a better home */
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DEFINE_SPINLOCK(rtc_lock);
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#ifdef CONFIG_RTC_DRV_CMOS_MODULE
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EXPORT_SYMBOL(rtc_lock);
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#endif
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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(struct sys_device *dev, pm_message_t state)
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{
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	struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
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	if (timer->suspend != NULL)
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		timer->suspend();
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	return 0;
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}
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static int timer_resume(struct sys_device *dev)
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{
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	struct sys_timer *timer = container_of(dev, struct sys_timer, dev);
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	if (timer->resume != NULL)
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		timer->resume();
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	return 0;
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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 sysdev_class timer_sysclass = {
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	.name		= "timer",
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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_sysfs(void)
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{
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	int ret = sysdev_class_register(&timer_sysclass);
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	if (ret == 0) {
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		system_timer->dev.cls = &timer_sysclass;
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		ret = sysdev_register(&system_timer->dev);
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	}
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	return ret;
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}
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device_initcall(timer_init_sysfs);
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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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#ifdef CONFIG_HAVE_SCHED_CLOCK
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	sched_clock_postinit();
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#endif
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}
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