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 <linux/kernel_stat.h>
8 #include <asm/cputime.h>
9
uptime_proc_show(struct seq_file * m,void * v)10 static int uptime_proc_show(struct seq_file *m, void *v)
11 {
12 struct timespec uptime;
13 struct timespec idle;
14 u64 idletime;
15 u64 nsec;
16 u32 rem;
17 int i;
18
19 idletime = 0;
20 for_each_possible_cpu(i)
21 idletime += (__force u64) kcpustat_cpu(i).cpustat[CPUTIME_IDLE];
22
23 do_posix_clock_monotonic_gettime(&uptime);
24 monotonic_to_bootbased(&uptime);
25 nsec = cputime64_to_jiffies64(idletime) * TICK_NSEC;
26 idle.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
27 idle.tv_nsec = rem;
28 seq_printf(m, "%lu.%02lu %lu.%02lu\n",
29 (unsigned long) uptime.tv_sec,
30 (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
31 (unsigned long) idle.tv_sec,
32 (idle.tv_nsec / (NSEC_PER_SEC / 100)));
33 return 0;
34 }
35
uptime_proc_open(struct inode * inode,struct file * file)36 static int uptime_proc_open(struct inode *inode, struct file *file)
37 {
38 return single_open(file, uptime_proc_show, NULL);
39 }
40
41 static const struct file_operations uptime_proc_fops = {
42 .open = uptime_proc_open,
43 .read = seq_read,
44 .llseek = seq_lseek,
45 .release = single_release,
46 };
47
proc_uptime_init(void)48 static int __init proc_uptime_init(void)
49 {
50 proc_create("uptime", 0, NULL, &uptime_proc_fops);
51 return 0;
52 }
53 module_init(proc_uptime_init);
54