xref: /openbmc/linux/arch/um/kernel/time.c (revision 20d00213)
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 prepare_timer(void * ptr)
52 {
53 	int usec = 1000000/hz();
54 	*(struct itimerval *)ptr = ((struct itimerval) { { 0, usec },
55 							 { 0, usec }});
56 }
57 
58 void disable_timer(void)
59 {
60 	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
61 	if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
62 	   (setitimer(ITIMER_REAL, &disable, NULL) < 0))
63 		printk("disnable_timer - setitimer failed, errno = %d\n",
64 		       errno);
65 	/* If there are signals already queued, after unblocking ignore them */
66 	set_handler(SIGALRM, SIG_IGN, 0, -1);
67 	set_handler(SIGVTALRM, SIG_IGN, 0, -1);
68 }
69 
70 void switch_timers(int to_real)
71 {
72 	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
73 	struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
74 							{ 0, 1000000/hz() }});
75 	int old, new;
76 
77 	if(to_real){
78 		old = ITIMER_VIRTUAL;
79 		new = ITIMER_REAL;
80 	}
81 	else {
82 		old = ITIMER_REAL;
83 		new = ITIMER_VIRTUAL;
84 	}
85 
86 	if((setitimer(old, &disable, NULL) < 0) ||
87 	   (setitimer(new, &enable, NULL)))
88 		printk("switch_timers - setitimer failed, errno = %d\n",
89 		       errno);
90 }
91 
92 void uml_idle_timer(void)
93 {
94 	if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
95 		panic("Couldn't unset SIGVTALRM handler");
96 
97 	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
98 		    SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
99 	set_interval(ITIMER_REAL);
100 }
101 
102 extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
103 
104 void time_init(void)
105 {
106 	struct timespec now;
107 
108 	if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
109 		panic("Couldn't set SIGVTALRM handler");
110 	set_interval(ITIMER_VIRTUAL);
111 
112 	do_posix_clock_monotonic_gettime(&now);
113 	wall_to_monotonic.tv_sec = -now.tv_sec;
114 	wall_to_monotonic.tv_nsec = -now.tv_nsec;
115 }
116 
117 /* Declared in linux/time.h, which can't be included here */
118 extern void clock_was_set(void);
119 
120 void do_gettimeofday(struct timeval *tv)
121 {
122 	unsigned long flags;
123 
124 	flags = time_lock();
125 	gettimeofday(tv, NULL);
126 	timeradd(tv, &local_offset, tv);
127 	time_unlock(flags);
128 	clock_was_set();
129 }
130 
131 int do_settimeofday(struct timespec *tv)
132 {
133 	struct timeval now;
134 	unsigned long flags;
135 	struct timeval tv_in;
136 
137 	if ((unsigned long) tv->tv_nsec >= UM_NSEC_PER_SEC)
138 		return -EINVAL;
139 
140 	tv_in.tv_sec = tv->tv_sec;
141 	tv_in.tv_usec = tv->tv_nsec / 1000;
142 
143 	flags = time_lock();
144 	gettimeofday(&now, NULL);
145 	timersub(&tv_in, &now, &local_offset);
146 	time_unlock(flags);
147 
148 	return(0);
149 }
150 
151 void idle_sleep(int secs)
152 {
153 	struct timespec ts;
154 
155 	ts.tv_sec = secs;
156 	ts.tv_nsec = 0;
157 	nanosleep(&ts, NULL);
158 }
159 
160 /* XXX This partly duplicates init_irq_signals */
161 
162 void user_time_init(void)
163 {
164 	set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
165 		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
166 		    SIGALRM, SIGUSR2, -1);
167 	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
168 		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
169 		    SIGVTALRM, SIGUSR2, -1);
170 	set_interval(ITIMER_VIRTUAL);
171 }
172