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/seq_file.h> |
6 | #include <linux/blkdev.h> |
7 | #include "internal.h" |
8 | |
9 | static int devinfo_show(struct seq_file *f, void *v) |
10 | { |
11 | int i = *(loff_t *) v; |
12 | |
13 | if (i < CHRDEV_MAJOR_MAX) { |
14 | if (i == 0) |
15 | seq_puts(m: f, s: "Character devices:\n" ); |
16 | chrdev_show(f, i); |
17 | } |
18 | #ifdef CONFIG_BLOCK |
19 | else { |
20 | i -= CHRDEV_MAJOR_MAX; |
21 | if (i == 0) |
22 | seq_puts(m: f, s: "\nBlock devices:\n" ); |
23 | blkdev_show(seqf: f, offset: i); |
24 | } |
25 | #endif |
26 | return 0; |
27 | } |
28 | |
29 | static void *devinfo_start(struct seq_file *f, loff_t *pos) |
30 | { |
31 | if (*pos < (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX)) |
32 | return pos; |
33 | return NULL; |
34 | } |
35 | |
36 | static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos) |
37 | { |
38 | (*pos)++; |
39 | if (*pos >= (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX)) |
40 | return NULL; |
41 | return pos; |
42 | } |
43 | |
44 | static void devinfo_stop(struct seq_file *f, void *v) |
45 | { |
46 | /* Nothing to do */ |
47 | } |
48 | |
49 | static const struct seq_operations devinfo_ops = { |
50 | .start = devinfo_start, |
51 | .next = devinfo_next, |
52 | .stop = devinfo_stop, |
53 | .show = devinfo_show |
54 | }; |
55 | |
56 | static int __init proc_devices_init(void) |
57 | { |
58 | struct proc_dir_entry *pde; |
59 | |
60 | pde = proc_create_seq("devices" , 0, NULL, &devinfo_ops); |
61 | pde_make_permanent(pde); |
62 | return 0; |
63 | } |
64 | fs_initcall(proc_devices_init); |
65 | |