proc: switch /proc/uptime to seq_file

and move it to fs/proc/uptime.c while I'm at it.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c
new file mode 100644
index 000000000000..0c10a0b3f146
--- /dev/null
+++ b/fs/proc/uptime.c
@@ -0,0 +1,43 @@
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/time.h>
+#include <asm/cputime.h>
+
+static int uptime_proc_show(struct seq_file *m, void *v)
+{
+        struct timespec uptime;
+        struct timespec idle;
+        cputime_t idletime = cputime_add(init_task.utime, init_task.stime);
+
+        do_posix_clock_monotonic_gettime(&uptime);
+        monotonic_to_bootbased(&uptime);
+        cputime_to_timespec(idletime, &idle);
+        seq_printf(m, "%lu.%02lu %lu.%02lu\n",
+                        (unsigned long) uptime.tv_sec,
+                        (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
+                        (unsigned long) idle.tv_sec,
+                        (idle.tv_nsec / (NSEC_PER_SEC / 100)));
+        return 0;
+}
+
+static int uptime_proc_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, uptime_proc_show, NULL);
+}
+
+static const struct file_operations uptime_proc_fops = {
+        .open           = uptime_proc_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static int __init proc_uptime_init(void)
+{
+        proc_create("uptime", 0, NULL, &uptime_proc_fops);
+        return 0;
+}
+module_init(proc_uptime_init);