tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <unistd.h>
9#include <time.h>
10#include <sys/time.h>
11#include <signal.h>
12#include <errno.h>
13#include "user_util.h"
14#include "kern_util.h"
15#include "user.h"
16#include "process.h"
17#include "kern_constants.h"
18#include "os.h"
19#include "uml-config.h"
20
21int set_interval(int is_virtual)
22{
23 int usec = 1000000/hz();
24 int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
25 struct itimerval interval = ((struct itimerval) { { 0, usec },
26 { 0, usec } });
27
28 if(setitimer(timer_type, &interval, NULL) == -1)
29 return -errno;
30
31 return 0;
32}
33
34#ifdef UML_CONFIG_MODE_TT
35void enable_timer(void)
36{
37 set_interval(1);
38}
39#endif
40
41void disable_timer(void)
42{
43 struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
44 if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
45 (setitimer(ITIMER_REAL, &disable, NULL) < 0))
46 printk("disnable_timer - setitimer failed, errno = %d\n",
47 errno);
48 /* If there are signals already queued, after unblocking ignore them */
49 signal(SIGALRM, SIG_IGN);
50 signal(SIGVTALRM, SIG_IGN);
51}
52
53void switch_timers(int to_real)
54{
55 struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
56 struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
57 { 0, 1000000/hz() }});
58 int old, new;
59
60 if(to_real){
61 old = ITIMER_VIRTUAL;
62 new = ITIMER_REAL;
63 }
64 else {
65 old = ITIMER_REAL;
66 new = ITIMER_VIRTUAL;
67 }
68
69 if((setitimer(old, &disable, NULL) < 0) ||
70 (setitimer(new, &enable, NULL)))
71 printk("switch_timers - setitimer failed, errno = %d\n",
72 errno);
73}
74
75#ifdef UML_CONFIG_MODE_TT
76void uml_idle_timer(void)
77{
78 if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
79 panic("Couldn't unset SIGVTALRM handler");
80
81 set_handler(SIGALRM, (__sighandler_t) alarm_handler,
82 SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
83 set_interval(0);
84}
85#endif
86
87unsigned long long os_nsecs(void)
88{
89 struct timeval tv;
90
91 gettimeofday(&tv, NULL);
92 return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
93}
94
95void idle_sleep(int secs)
96{
97 struct timespec ts;
98
99 ts.tv_sec = secs;
100 ts.tv_nsec = 0;
101 nanosleep(&ts, NULL);
102}