xref: /linux/arch/um/os-Linux/time.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 
20 /* XXX This really needs to be declared and initialized in a kernel file since
21  * it's in <linux/time.h>
22  */
23 extern struct timespec wall_to_monotonic;
24 
25 static void set_interval(int timer_type)
26 {
27 	int usec = 1000000/hz();
28 	struct itimerval interval = ((struct itimerval) { { 0, usec },
29 							  { 0, usec } });
30 
31 	if(setitimer(timer_type, &interval, NULL) == -1)
32 		panic("setitimer failed - errno = %d\n", errno);
33 }
34 
35 void enable_timer(void)
36 {
37 	set_interval(ITIMER_VIRTUAL);
38 }
39 
40 void disable_timer(void)
41 {
42 	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
43 	if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
44 	   (setitimer(ITIMER_REAL, &disable, NULL) < 0))
45 		printk("disnable_timer - setitimer failed, errno = %d\n",
46 		       errno);
47 	/* If there are signals already queued, after unblocking ignore them */
48 	set_handler(SIGALRM, SIG_IGN, 0, -1);
49 	set_handler(SIGVTALRM, SIG_IGN, 0, -1);
50 }
51 
52 void switch_timers(int to_real)
53 {
54 	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
55 	struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
56 							{ 0, 1000000/hz() }});
57 	int old, new;
58 
59 	if(to_real){
60 		old = ITIMER_VIRTUAL;
61 		new = ITIMER_REAL;
62 	}
63 	else {
64 		old = ITIMER_REAL;
65 		new = ITIMER_VIRTUAL;
66 	}
67 
68 	if((setitimer(old, &disable, NULL) < 0) ||
69 	   (setitimer(new, &enable, NULL)))
70 		printk("switch_timers - setitimer failed, errno = %d\n",
71 		       errno);
72 }
73 
74 void uml_idle_timer(void)
75 {
76 	if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
77 		panic("Couldn't unset SIGVTALRM handler");
78 
79 	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
80 		    SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
81 	set_interval(ITIMER_REAL);
82 }
83 
84 void time_init(void)
85 {
86 	if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
87 		panic("Couldn't set SIGVTALRM handler");
88 	set_interval(ITIMER_VIRTUAL);
89 	time_init_kern();
90 }
91 
92 unsigned long long os_nsecs(void)
93 {
94 	struct timeval tv;
95 
96 	gettimeofday(&tv, NULL);
97 	return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
98 }
99 
100 void idle_sleep(int secs)
101 {
102 	struct timespec ts;
103 
104 	ts.tv_sec = secs;
105 	ts.tv_nsec = 0;
106 	nanosleep(&ts, NULL);
107 }
108 
109 /* XXX This partly duplicates init_irq_signals */
110 
111 void user_time_init(void)
112 {
113 	set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
114 		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
115 		    SIGALRM, SIGUSR2, -1);
116 	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
117 		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
118 		    SIGVTALRM, SIGUSR2, -1);
119 	set_interval(ITIMER_VIRTUAL);
120 }
121