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/*
* Linux timers.
*
* Copyright (C) 1996 The University of Utah and the Computer Systems
* Laboratory at the University of Utah (CSL)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Author: Shantanu Goel, University of Utah CSL
*/
/*
* linux/kernel/sched.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <asm/system.h>
unsigned long volatile jiffies = 0;
/*
* Mask of active timers.
*/
unsigned long timer_active = 0;
/*
* List of timeout routines.
*/
struct timer_struct timer_table[32];
/*
* The head for the timer-list has a "expires" field of MAX_UINT,
* and the sorting routine counts on this..
*/
static struct timer_list timer_head =
{
&timer_head, &timer_head, ~0, 0, NULL
};
#define SLOW_BUT_DEBUGGING_TIMERS 0
void
add_timer(struct timer_list *timer)
{
unsigned long flags;
struct timer_list *p;
#if SLOW_BUT_DEBUGGING_TIMERS
if (timer->next || timer->prev) {
printk("add_timer() called with non-zero list from %p\n",
__builtin_return_address(0));
return;
}
#endif
p = &timer_head;
save_flags(flags);
cli();
do {
p = p->next;
} while (timer->expires > p->expires);
timer->next = p;
timer->prev = p->prev;
p->prev = timer;
timer->prev->next = timer;
restore_flags(flags);
}
int
del_timer(struct timer_list *timer)
{
unsigned long flags;
#if SLOW_BUT_DEBUGGING_TIMERS
struct timer_list * p;
p = &timer_head;
save_flags(flags);
cli();
while ((p = p->next) != &timer_head) {
if (p == timer) {
timer->next->prev = timer->prev;
timer->prev->next = timer->next;
timer->next = timer->prev = NULL;
restore_flags(flags);
return 1;
}
}
if (timer->next || timer->prev)
printk("del_timer() called from %p with timer not initialized\n",
__builtin_return_address(0));
restore_flags(flags);
return 0;
#else
struct timer_list * next;
int ret = 0;
save_flags(flags);
cli();
if ((next = timer->next) != NULL) {
(next->prev = timer->prev)->next = next;
timer->next = timer->prev = NULL;
ret = 1;
}
restore_flags(flags);
return ret;
#endif
}
/*
* Timer software interrupt handler.
*/
void
timer_bh()
{
unsigned long mask;
struct timer_struct *tp;
struct timer_list * timer;
cli();
while ((timer = timer_head.next) != &timer_head
&& timer->expires <= jiffies) {
void (*fn)(unsigned long) = timer->function;
unsigned long data = timer->data;
timer->next->prev = timer->prev;
timer->prev->next = timer->next;
timer->next = timer->prev = NULL;
sti();
fn(data);
cli();
}
sti();
for (mask = 1, tp = timer_table; mask; tp++, mask <<= 1) {
if (mask > timer_active)
break;
if ((mask & timer_active)
&& tp->expires > jiffies) {
timer_active &= ~mask;
(*tp->fn)();
sti();
}
}
}
int linux_timer_print = 0;
/*
* Timer interrupt handler.
*/
void
linux_timer_intr()
{
unsigned long mask;
struct timer_struct *tp;
extern int pic_mask[];
jiffies++;
for (mask = 1, tp = timer_table; mask; tp++, mask += mask) {
if (mask > timer_active)
break;
if (!(mask & timer_active))
continue;
if (tp->expires > jiffies)
continue;
mark_bh(TIMER_BH);
}
if (timer_head.next->expires <= jiffies)
mark_bh(TIMER_BH);
if (tq_timer != &tq_last)
mark_bh(TQUEUE_BH);
if (linux_timer_print)
printf ("linux_timer_intr: pic_mask[0] %x\n", pic_mask[0]);
}
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