136 строки
3.2 KiB
C
136 строки
3.2 KiB
C
/*
|
|
* Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
|
|
* Licensed under the GPL
|
|
*/
|
|
|
|
#include <stddef.h>
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
#include <time.h>
|
|
#include <sys/time.h>
|
|
#include "kern_constants.h"
|
|
#include "os.h"
|
|
#include "user.h"
|
|
|
|
int set_interval(void)
|
|
{
|
|
int usec = UM_USEC_PER_SEC / UM_HZ;
|
|
struct itimerval interval = ((struct itimerval) { { 0, usec },
|
|
{ 0, usec } });
|
|
|
|
if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
|
|
return -errno;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int timer_one_shot(int ticks)
|
|
{
|
|
unsigned long usec = ticks * UM_USEC_PER_SEC / UM_HZ;
|
|
unsigned long sec = usec / UM_USEC_PER_SEC;
|
|
struct itimerval interval;
|
|
|
|
usec %= UM_USEC_PER_SEC;
|
|
interval = ((struct itimerval) { { 0, 0 }, { sec, usec } });
|
|
|
|
if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
|
|
return -errno;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* timeval_to_ns - Convert timeval to nanoseconds
|
|
* @ts: pointer to the timeval variable to be converted
|
|
*
|
|
* Returns the scalar nanosecond representation of the timeval
|
|
* parameter.
|
|
*
|
|
* Ripped from linux/time.h because it's a kernel header, and thus
|
|
* unusable from here.
|
|
*/
|
|
static inline long long timeval_to_ns(const struct timeval *tv)
|
|
{
|
|
return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
|
|
tv->tv_usec * UM_NSEC_PER_USEC;
|
|
}
|
|
|
|
long long disable_timer(void)
|
|
{
|
|
struct itimerval time = ((struct itimerval) { { 0, 0 }, { 0, 0 } });
|
|
|
|
if (setitimer(ITIMER_VIRTUAL, &time, &time) < 0)
|
|
printk(UM_KERN_ERR "disable_timer - setitimer failed, "
|
|
"errno = %d\n", errno);
|
|
|
|
return timeval_to_ns(&time.it_value);
|
|
}
|
|
|
|
long long os_nsecs(void)
|
|
{
|
|
struct timeval tv;
|
|
|
|
gettimeofday(&tv, NULL);
|
|
return timeval_to_ns(&tv);
|
|
}
|
|
|
|
#ifdef UML_CONFIG_NO_HZ
|
|
static int after_sleep_interval(struct timespec *ts)
|
|
{
|
|
return 0;
|
|
}
|
|
#else
|
|
static inline long long timespec_to_us(const struct timespec *ts)
|
|
{
|
|
return ((long long) ts->tv_sec * UM_USEC_PER_SEC) +
|
|
ts->tv_nsec / UM_NSEC_PER_USEC;
|
|
}
|
|
|
|
static int after_sleep_interval(struct timespec *ts)
|
|
{
|
|
int usec = UM_USEC_PER_SEC / UM_HZ;
|
|
long long start_usecs = timespec_to_us(ts);
|
|
struct timeval tv;
|
|
struct itimerval interval;
|
|
|
|
/*
|
|
* It seems that rounding can increase the value returned from
|
|
* setitimer to larger than the one passed in. Over time,
|
|
* this will cause the remaining time to be greater than the
|
|
* tick interval. If this happens, then just reduce the first
|
|
* tick to the interval value.
|
|
*/
|
|
if (start_usecs > usec)
|
|
start_usecs = usec;
|
|
tv = ((struct timeval) { .tv_sec = start_usecs / UM_USEC_PER_SEC,
|
|
.tv_usec = start_usecs % UM_USEC_PER_SEC });
|
|
interval = ((struct itimerval) { { 0, usec }, tv });
|
|
|
|
if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
|
|
return -errno;
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
extern void alarm_handler(int sig, struct sigcontext *sc);
|
|
|
|
void idle_sleep(unsigned long long nsecs)
|
|
{
|
|
struct timespec ts;
|
|
|
|
/*
|
|
* nsecs can come in as zero, in which case, this starts a
|
|
* busy loop. To prevent this, reset nsecs to the tick
|
|
* interval if it is zero.
|
|
*/
|
|
if (nsecs == 0)
|
|
nsecs = UM_NSEC_PER_SEC / UM_HZ;
|
|
ts = ((struct timespec) { .tv_sec = nsecs / UM_NSEC_PER_SEC,
|
|
.tv_nsec = nsecs % UM_NSEC_PER_SEC });
|
|
|
|
if (nanosleep(&ts, &ts) == 0)
|
|
alarm_handler(SIGVTALRM, NULL);
|
|
after_sleep_interval(&ts);
|
|
}
|