xref: /openbmc/linux/fs/proc/uptime.c (revision b627b4ed)
1 #include <linux/fs.h>
2 #include <linux/init.h>
3 #include <linux/proc_fs.h>
4 #include <linux/sched.h>
5 #include <linux/seq_file.h>
6 #include <linux/time.h>
7 #include <asm/cputime.h>
8 
9 static int uptime_proc_show(struct seq_file *m, void *v)
10 {
11 	struct timespec uptime;
12 	struct timespec idle;
13 	cputime_t idletime = cputime_add(init_task.utime, init_task.stime);
14 
15 	do_posix_clock_monotonic_gettime(&uptime);
16 	monotonic_to_bootbased(&uptime);
17 	cputime_to_timespec(idletime, &idle);
18 	seq_printf(m, "%lu.%02lu %lu.%02lu\n",
19 			(unsigned long) uptime.tv_sec,
20 			(uptime.tv_nsec / (NSEC_PER_SEC / 100)),
21 			(unsigned long) idle.tv_sec,
22 			(idle.tv_nsec / (NSEC_PER_SEC / 100)));
23 	return 0;
24 }
25 
26 static int uptime_proc_open(struct inode *inode, struct file *file)
27 {
28 	return single_open(file, uptime_proc_show, NULL);
29 }
30 
31 static const struct file_operations uptime_proc_fops = {
32 	.open		= uptime_proc_open,
33 	.read		= seq_read,
34 	.llseek		= seq_lseek,
35 	.release	= single_release,
36 };
37 
38 static int __init proc_uptime_init(void)
39 {
40 	proc_create("uptime", 0, NULL, &uptime_proc_fops);
41 	return 0;
42 }
43 module_init(proc_uptime_init);
44