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/*
* Copyright (C) 2000 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/kernel.h"
#include "linux/module.h"
#include "linux/unistd.h"
#include "linux/stddef.h"
#include "linux/spinlock.h"
#include "linux/time.h"
#include "linux/sched.h"
#include "linux/interrupt.h"
#include "linux/init.h"
#include "linux/delay.h"
#include "linux/hrtimer.h"
#include "asm/irq.h"
#include "asm/param.h"
#include "asm/current.h"
#include "kern_util.h"
#include "user_util.h"
#include "mode.h"
#include "os.h"
int hz(void)
{
return(HZ);
}
/*
* Scheduler clock - returns current time in nanosec units.
*/
unsigned long long sched_clock(void)
{
return (unsigned long long)jiffies_64 * (1000000000 / HZ);
}
/* Changed at early boot */
int timer_irq_inited = 0;
static int first_tick;
static unsigned long long prev_nsecs;
#ifdef CONFIG_UML_REAL_TIME_CLOCK
static long long delta; /* Deviation per interval */
#endif
void timer_irq(union uml_pt_regs *regs)
{
unsigned long long ticks = 0;
if(!timer_irq_inited){
/* This is to ensure that ticks don't pile up when
* the timer handler is suspended */
first_tick = 0;
return;
}
if(first_tick){
#ifdef CONFIG_UML_REAL_TIME_CLOCK
/* We've had 1 tick */
unsigned long long nsecs = os_nsecs();
delta += nsecs - prev_nsecs;
prev_nsecs = nsecs;
/* Protect against the host clock being set backwards */
if(delta < 0)
delta = 0;
ticks += (delta * HZ) / BILLION;
delta -= (ticks * BILLION) / HZ;
#else
ticks = 1;
#endif
}
else {
prev_nsecs = os_nsecs();
first_tick = 1;
}
while(ticks > 0){
do_IRQ(TIMER_IRQ, regs);
ticks--;
}
}
static DEFINE_SPINLOCK(timer_spinlock);
static unsigned long long local_offset = 0;
static inline unsigned long long get_time(void)
{
unsigned long long nsecs;
unsigned long flags;
spin_lock_irqsave(&timer_spinlock, flags);
nsecs = os_nsecs();
nsecs += local_offset;
spin_unlock_irqrestore(&timer_spinlock, flags);
return nsecs;
}
irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
{
unsigned long long nsecs;
unsigned long flags;
write_seqlock_irqsave(&xtime_lock, flags);
do_timer(regs);
nsecs = get_time() + local_offset;
xtime.tv_sec = nsecs / NSEC_PER_SEC;
xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC;
write_sequnlock_irqrestore(&xtime_lock, flags);
return IRQ_HANDLED;
}
static void register_timer(void)
{
int err;
err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL);
if(err != 0)
printk(KERN_ERR "timer_init : request_irq failed - "
"errno = %d\n", -err);
timer_irq_inited = 1;
user_time_init();
}
extern void (*late_time_init)(void);
void time_init(void)
{
long long nsecs;
nsecs = os_nsecs();
set_normalized_timespec(&wall_to_monotonic, -nsecs / BILLION,
-nsecs % BILLION);
late_time_init = register_timer;
}
void do_gettimeofday(struct timeval *tv)
{
unsigned long long nsecs = get_time();
tv->tv_sec = nsecs / NSEC_PER_SEC;
/* Careful about calculations here - this was originally done as
* (nsecs - tv->tv_sec * NSEC_PER_SEC) / NSEC_PER_USEC
* which gave bogus (> 1000000) values. Dunno why, suspect gcc
* (4.0.0) miscompiled it, or there's a subtle 64/32-bit conversion
* problem that I missed.
*/
nsecs -= tv->tv_sec * NSEC_PER_SEC;
tv->tv_usec = (unsigned long) nsecs / NSEC_PER_USEC;
}
static inline void set_time(unsigned long long nsecs)
{
unsigned long long now;
unsigned long flags;
spin_lock_irqsave(&timer_spinlock, flags);
now = os_nsecs();
local_offset = nsecs - now;
spin_unlock_irqrestore(&timer_spinlock, flags);
clock_was_set();
}
int do_settimeofday(struct timespec *tv)
{
set_time((unsigned long long) tv->tv_sec * NSEC_PER_SEC + tv->tv_nsec);
return 0;
}
void timer_handler(int sig, union uml_pt_regs *regs)
{
local_irq_disable();
irq_enter();
update_process_times(CHOOSE_MODE(
(UPT_SC(regs) && user_context(UPT_SP(regs))),
(regs)->skas.is_user));
irq_exit();
local_irq_enable();
if(current_thread->cpu == 0)
timer_irq(regs);
}
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