mirror of https://gitee.com/openkylin/linux.git
189 lines
3.6 KiB
C
189 lines
3.6 KiB
C
/*
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* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
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* Licensed under the GPL
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*/
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#include "linux/kernel.h"
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#include "linux/module.h"
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#include "linux/unistd.h"
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#include "linux/stddef.h"
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#include "linux/spinlock.h"
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#include "linux/time.h"
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#include "linux/sched.h"
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#include "linux/interrupt.h"
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#include "linux/init.h"
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#include "linux/delay.h"
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#include "asm/irq.h"
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#include "asm/param.h"
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#include "asm/current.h"
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#include "kern_util.h"
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#include "user_util.h"
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#include "time_user.h"
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#include "mode.h"
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#include "os.h"
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u64 jiffies_64 = INITIAL_JIFFIES;
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EXPORT_SYMBOL(jiffies_64);
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int hz(void)
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{
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return(HZ);
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}
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/*
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* Scheduler clock - returns current time in nanosec units.
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*/
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unsigned long long sched_clock(void)
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{
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return (unsigned long long)jiffies_64 * (1000000000 / HZ);
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}
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/* Changed at early boot */
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int timer_irq_inited = 0;
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static int first_tick;
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static unsigned long long prev_usecs;
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#ifdef CONFIG_UML_REAL_TIME_CLOCK
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static long long delta; /* Deviation per interval */
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#endif
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void timer_irq(union uml_pt_regs *regs)
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{
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unsigned long long ticks = 0;
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if(!timer_irq_inited){
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/* This is to ensure that ticks don't pile up when
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* the timer handler is suspended */
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first_tick = 0;
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return;
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}
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if(first_tick){
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#ifdef CONFIG_UML_REAL_TIME_CLOCK
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/* We've had 1 tick */
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unsigned long long usecs = os_usecs();
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delta += usecs - prev_usecs;
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prev_usecs = usecs;
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/* Protect against the host clock being set backwards */
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if(delta < 0)
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delta = 0;
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ticks += (delta * HZ) / MILLION;
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delta -= (ticks * MILLION) / HZ;
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#else
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ticks = 1;
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#endif
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}
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else {
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prev_usecs = os_usecs();
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first_tick = 1;
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}
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while(ticks > 0){
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do_IRQ(TIMER_IRQ, regs);
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ticks--;
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}
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}
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void boot_timer_handler(int sig)
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{
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struct pt_regs regs;
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CHOOSE_MODE((void)
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(UPT_SC(®s.regs) = (struct sigcontext *) (&sig + 1)),
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(void) (regs.regs.skas.is_user = 0));
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do_timer(®s);
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}
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irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
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{
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unsigned long flags;
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do_timer(regs);
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write_seqlock_irqsave(&xtime_lock, flags);
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timer();
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write_sequnlock_irqrestore(&xtime_lock, flags);
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return(IRQ_HANDLED);
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}
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long um_time(int __user *tloc)
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{
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struct timeval now;
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do_gettimeofday(&now);
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if (tloc) {
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if (put_user(now.tv_sec, tloc))
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now.tv_sec = -EFAULT;
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}
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return now.tv_sec;
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}
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long um_stime(int __user *tptr)
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{
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int value;
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struct timespec new;
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if (get_user(value, tptr))
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return -EFAULT;
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new.tv_sec = value;
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new.tv_nsec = 0;
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do_settimeofday(&new);
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return 0;
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}
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void timer_handler(int sig, union uml_pt_regs *regs)
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{
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local_irq_disable();
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irq_enter();
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update_process_times(CHOOSE_MODE(user_context(UPT_SP(regs)),
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(regs)->skas.is_user));
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irq_exit();
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local_irq_enable();
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if(current_thread->cpu == 0)
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timer_irq(regs);
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}
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static DEFINE_SPINLOCK(timer_spinlock);
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unsigned long time_lock(void)
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{
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unsigned long flags;
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spin_lock_irqsave(&timer_spinlock, flags);
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return(flags);
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}
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void time_unlock(unsigned long flags)
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{
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spin_unlock_irqrestore(&timer_spinlock, flags);
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}
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int __init timer_init(void)
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{
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int err;
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user_time_init();
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err = request_irq(TIMER_IRQ, um_timer, SA_INTERRUPT, "timer", NULL);
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if(err != 0)
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printk(KERN_ERR "timer_init : request_irq failed - "
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"errno = %d\n", -err);
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timer_irq_inited = 1;
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return(0);
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}
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__initcall(timer_init);
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/*
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* Overrides for Emacs so that we follow Linus's tabbing style.
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* Emacs will notice this stuff at the end of the file and automatically
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* adjust the settings for this buffer only. This must remain at the end
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* of the file.
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* ---------------------------------------------------------------------------
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* Local variables:
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* c-file-style: "linux"
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* End:
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*/
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