xref: /linux/arch/um/os-Linux/time.c (revision 42fda66387daa53538ae13a2c858396aaf037158)
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 "kern_util.h"
14 #include "user.h"
15 #include "process.h"
16 #include "kern_constants.h"
17 #include "os.h"
18 #include "uml-config.h"
19 
20 int set_interval(int is_virtual)
21 {
22 	int usec = 1000000/hz();
23 	int timer_type = is_virtual ? ITIMER_VIRTUAL : ITIMER_REAL;
24 	struct itimerval interval = ((struct itimerval) { { 0, usec },
25 							  { 0, usec } });
26 
27 	if(setitimer(timer_type, &interval, NULL) == -1)
28 		return -errno;
29 
30 	return 0;
31 }
32 
33 void disable_timer(void)
34 {
35 	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
36 	if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
37 	   (setitimer(ITIMER_REAL, &disable, NULL) < 0))
38 		printk("disnable_timer - setitimer failed, errno = %d\n",
39 		       errno);
40 	/* If there are signals already queued, after unblocking ignore them */
41 	signal(SIGALRM, SIG_IGN);
42 	signal(SIGVTALRM, SIG_IGN);
43 }
44 
45 void switch_timers(int to_real)
46 {
47 	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
48 	struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
49 							{ 0, 1000000/hz() }});
50 	int old, new;
51 
52 	if(to_real){
53 		old = ITIMER_VIRTUAL;
54 		new = ITIMER_REAL;
55 	}
56 	else {
57 		old = ITIMER_REAL;
58 		new = ITIMER_VIRTUAL;
59 	}
60 
61 	if((setitimer(old, &disable, NULL) < 0) ||
62 	   (setitimer(new, &enable, NULL)))
63 		printk("switch_timers - setitimer failed, errno = %d\n",
64 		       errno);
65 }
66 
67 unsigned long long os_nsecs(void)
68 {
69 	struct timeval tv;
70 
71 	gettimeofday(&tv, NULL);
72 	return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
73 }
74 
75 void idle_sleep(int secs)
76 {
77 	struct timespec ts;
78 
79 	ts.tv_sec = secs;
80 	ts.tv_nsec = 0;
81 	nanosleep(&ts, NULL);
82 }
83