xref: /openbmc/linux/fs/proc/consoles.c (revision d0b73b48)
1 /*
2  * Copyright (c) 2010 Werner Fink, Jiri Slaby
3  *
4  * Licensed under GPLv2
5  */
6 
7 #include <linux/console.h>
8 #include <linux/kernel.h>
9 #include <linux/proc_fs.h>
10 #include <linux/seq_file.h>
11 #include <linux/tty_driver.h>
12 
13 /*
14  * This is handler for /proc/consoles
15  */
16 static int show_console_dev(struct seq_file *m, void *v)
17 {
18 	static const struct {
19 		short flag;
20 		char name;
21 	} con_flags[] = {
22 		{ CON_ENABLED,		'E' },
23 		{ CON_CONSDEV,		'C' },
24 		{ CON_BOOT,		'B' },
25 		{ CON_PRINTBUFFER,	'p' },
26 		{ CON_BRL,		'b' },
27 		{ CON_ANYTIME,		'a' },
28 	};
29 	char flags[ARRAY_SIZE(con_flags) + 1];
30 	struct console *con = v;
31 	unsigned int a;
32 	int len;
33 	dev_t dev = 0;
34 
35 	if (con->device) {
36 		const struct tty_driver *driver;
37 		int index;
38 		driver = con->device(con, &index);
39 		if (driver) {
40 			dev = MKDEV(driver->major, driver->minor_start);
41 			dev += index;
42 		}
43 	}
44 
45 	for (a = 0; a < ARRAY_SIZE(con_flags); a++)
46 		flags[a] = (con->flags & con_flags[a].flag) ?
47 			con_flags[a].name : ' ';
48 	flags[a] = 0;
49 
50 	seq_printf(m, "%s%d%n", con->name, con->index, &len);
51 	len = 21 - len;
52 	if (len < 1)
53 		len = 1;
54 	seq_printf(m, "%*c%c%c%c (%s)", len, ' ', con->read ? 'R' : '-',
55 			con->write ? 'W' : '-', con->unblank ? 'U' : '-',
56 			flags);
57 	if (dev)
58 		seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));
59 
60 	seq_printf(m, "\n");
61 
62 	return 0;
63 }
64 
65 static void *c_start(struct seq_file *m, loff_t *pos)
66 {
67 	struct console *con;
68 	loff_t off = 0;
69 
70 	console_lock();
71 	for_each_console(con)
72 		if (off++ == *pos)
73 			break;
74 
75 	return con;
76 }
77 
78 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
79 {
80 	struct console *con = v;
81 	++*pos;
82 	return con->next;
83 }
84 
85 static void c_stop(struct seq_file *m, void *v)
86 {
87 	console_unlock();
88 }
89 
90 static const struct seq_operations consoles_op = {
91 	.start	= c_start,
92 	.next	= c_next,
93 	.stop	= c_stop,
94 	.show	= show_console_dev
95 };
96 
97 static int consoles_open(struct inode *inode, struct file *file)
98 {
99 	return seq_open(file, &consoles_op);
100 }
101 
102 static const struct file_operations proc_consoles_operations = {
103 	.open		= consoles_open,
104 	.read		= seq_read,
105 	.llseek		= seq_lseek,
106 	.release	= seq_release,
107 };
108 
109 static int __init proc_consoles_init(void)
110 {
111 	proc_create("consoles", 0, NULL, &proc_consoles_operations);
112 	return 0;
113 }
114 module_init(proc_consoles_init);
115