b160fb6309
Now, the idle loop now longer needs SIGALRM firing - it can just sleep for the requisite amount of time and fake a timer interrupt when it finishes. Any use of ITIMER_REAL now goes away. disable_timer only turns off ITIMER_VIRTUAL. switch_timers is no longer needed, so it, and all calls, goes away. disable_timer now returns the amount of time remaining on the timer. default_idle uses this to tell idle_sleep how long to sleep. idle_sleep will call alarm_handler if nanosleep returns 0, which is the case if it didn't return early due to an interrupt. Otherwise, it just returns. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
70 lines
1.4 KiB
C
70 lines
1.4 KiB
C
/*
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*/
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#include <stddef.h>
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#include <errno.h>
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#include <signal.h>
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#include <time.h>
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#include <sys/time.h>
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#include "kern_constants.h"
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#include "os.h"
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#include "user.h"
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int set_interval(void)
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{
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int usec = 1000000/UM_HZ;
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struct itimerval interval = ((struct itimerval) { { 0, usec },
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{ 0, usec } });
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if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
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return -errno;
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return 0;
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}
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int timer_one_shot(int ticks)
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{
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unsigned long usec = ticks * 1000000 / UM_HZ;
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unsigned long sec = usec / 1000000;
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struct itimerval interval;
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usec %= 1000000;
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interval = ((struct itimerval) { { 0, 0 }, { sec, usec } });
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if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
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return -errno;
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return 0;
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}
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unsigned long long disable_timer(void)
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{
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struct itimerval time = ((struct itimerval) { { 0, 0 }, { 0, 0 } });
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if(setitimer(ITIMER_VIRTUAL, &time, &time) < 0)
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printk(UM_KERN_ERR "disable_timer - setitimer failed, "
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"errno = %d\n", errno);
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return tv_to_nsec(&time.it_value);
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}
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unsigned long long os_nsecs(void)
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{
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struct timeval tv;
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gettimeofday(&tv, NULL);
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return timeval_to_ns(&tv);
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}
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extern void alarm_handler(int sig, struct sigcontext *sc);
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void idle_sleep(unsigned long long nsecs)
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{
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struct timespec ts = { .tv_sec = nsecs / BILLION,
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.tv_nsec = nsecs % BILLION };
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if (nanosleep(&ts, &ts) == 0)
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alarm_handler(SIGVTALRM, NULL);
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}
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