xref: /linux/arch/um/kernel/time.c (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
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 "signal_user.h"
18 #include "time_user.h"
19 #include "kern_constants.h"
20 
21 /* XXX This really needs to be declared and initialized in a kernel file since
22  * it's in <linux/time.h>
23  */
24 extern struct timespec wall_to_monotonic;
25 
26 extern struct timeval xtime;
27 
28 struct timeval local_offset = { 0, 0 };
29 
30 void timer(void)
31 {
32 	gettimeofday(&xtime, NULL);
33 	timeradd(&xtime, &local_offset, &xtime);
34 }
35 
36 static void set_interval(int timer_type)
37 {
38 	int usec = 1000000/hz();
39 	struct itimerval interval = ((struct itimerval) { { 0, usec },
40 							  { 0, usec } });
41 
42 	if(setitimer(timer_type, &interval, NULL) == -1)
43 		panic("setitimer failed - errno = %d\n", errno);
44 }
45 
46 void enable_timer(void)
47 {
48 	set_interval(ITIMER_VIRTUAL);
49 }
50 
51 void disable_timer(void)
52 {
53 	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
54 	if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
55 	   (setitimer(ITIMER_REAL, &disable, NULL) < 0))
56 		printk("disnable_timer - setitimer failed, errno = %d\n",
57 		       errno);
58 	/* If there are signals already queued, after unblocking ignore them */
59 	set_handler(SIGALRM, SIG_IGN, 0, -1);
60 	set_handler(SIGVTALRM, SIG_IGN, 0, -1);
61 }
62 
63 void switch_timers(int to_real)
64 {
65 	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
66 	struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
67 							{ 0, 1000000/hz() }});
68 	int old, new;
69 
70 	if(to_real){
71 		old = ITIMER_VIRTUAL;
72 		new = ITIMER_REAL;
73 	}
74 	else {
75 		old = ITIMER_REAL;
76 		new = ITIMER_VIRTUAL;
77 	}
78 
79 	if((setitimer(old, &disable, NULL) < 0) ||
80 	   (setitimer(new, &enable, NULL)))
81 		printk("switch_timers - setitimer failed, errno = %d\n",
82 		       errno);
83 }
84 
85 void uml_idle_timer(void)
86 {
87 	if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
88 		panic("Couldn't unset SIGVTALRM handler");
89 
90 	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
91 		    SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
92 	set_interval(ITIMER_REAL);
93 }
94 
95 extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
96 
97 void time_init(void)
98 {
99 	struct timespec now;
100 
101 	if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
102 		panic("Couldn't set SIGVTALRM handler");
103 	set_interval(ITIMER_VIRTUAL);
104 
105 	do_posix_clock_monotonic_gettime(&now);
106 	wall_to_monotonic.tv_sec = -now.tv_sec;
107 	wall_to_monotonic.tv_nsec = -now.tv_nsec;
108 }
109 
110 /* Declared in linux/time.h, which can't be included here */
111 extern void clock_was_set(void);
112 
113 void do_gettimeofday(struct timeval *tv)
114 {
115 	unsigned long flags;
116 
117 	flags = time_lock();
118 	gettimeofday(tv, NULL);
119 	timeradd(tv, &local_offset, tv);
120 	time_unlock(flags);
121 	clock_was_set();
122 }
123 
124 int do_settimeofday(struct timespec *tv)
125 {
126 	struct timeval now;
127 	unsigned long flags;
128 	struct timeval tv_in;
129 
130 	if ((unsigned long) tv->tv_nsec >= UM_NSEC_PER_SEC)
131 		return -EINVAL;
132 
133 	tv_in.tv_sec = tv->tv_sec;
134 	tv_in.tv_usec = tv->tv_nsec / 1000;
135 
136 	flags = time_lock();
137 	gettimeofday(&now, NULL);
138 	timersub(&tv_in, &now, &local_offset);
139 	time_unlock(flags);
140 
141 	return(0);
142 }
143 
144 void idle_sleep(int secs)
145 {
146 	struct timespec ts;
147 
148 	ts.tv_sec = secs;
149 	ts.tv_nsec = 0;
150 	nanosleep(&ts, NULL);
151 }
152 
153 /* XXX This partly duplicates init_irq_signals */
154 
155 void user_time_init(void)
156 {
157 	set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
158 		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
159 		    SIGALRM, SIGUSR2, -1);
160 	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
161 		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
162 		    SIGVTALRM, SIGUSR2, -1);
163 	set_interval(ITIMER_VIRTUAL);
164 }
165