1// SPDX-License-Identifier: GPL-2.0
2#include <linux/fs.h>
3#include <linux/init.h>
4#include <linux/proc_fs.h>
5#include <linux/sched.h>
6#include <linux/seq_file.h>
7#include <linux/time.h>
8#include <linux/time_namespace.h>
9#include <linux/kernel_stat.h>
10#include "internal.h"
11
12static int uptime_proc_show(struct seq_file *m, void *v)
13{
14 struct timespec64 uptime;
15 struct timespec64 idle;
16 u64 idle_nsec;
17 u32 rem;
18 int i;
19
20 idle_nsec = 0;
21 for_each_possible_cpu(i) {
22 struct kernel_cpustat kcs;
23
24 kcpustat_cpu_fetch(dst: &kcs, cpu: i);
25 idle_nsec += get_idle_time(kcs: &kcs, cpu: i);
26 }
27
28 ktime_get_boottime_ts64(ts: &uptime);
29 timens_add_boottime(ts: &uptime);
30
31 idle.tv_sec = div_u64_rem(dividend: idle_nsec, NSEC_PER_SEC, remainder: &rem);
32 idle.tv_nsec = rem;
33 seq_printf(m, fmt: "%lu.%02lu %lu.%02lu\n",
34 (unsigned long) uptime.tv_sec,
35 (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
36 (unsigned long) idle.tv_sec,
37 (idle.tv_nsec / (NSEC_PER_SEC / 100)));
38 return 0;
39}
40
41static int __init proc_uptime_init(void)
42{
43 struct proc_dir_entry *pde;
44
45 pde = proc_create_single("uptime", 0, NULL, uptime_proc_show);
46 pde_make_permanent(pde);
47 return 0;
48}
49fs_initcall(proc_uptime_init);
50