[S390] uaccess_pt: add missing down_read() and convert to is_init().
[deliverable/linux.git] / drivers / s390 / char / ctrlchar.c
CommitLineData
1da177e4
LT
1/*
2 * drivers/s390/char/ctrlchar.c
3 * Unified handling of special chars.
4 *
5 * Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
7 *
8 */
9
1da177e4
LT
10#include <linux/stddef.h>
11#include <asm/errno.h>
12#include <linux/sysrq.h>
13#include <linux/ctype.h>
14
15#include "ctrlchar.h"
16
17#ifdef CONFIG_MAGIC_SYSRQ
18static int ctrlchar_sysrq_key;
19
20static void
21ctrlchar_handle_sysrq(void *tty)
22{
5a489b98 23 handle_sysrq(ctrlchar_sysrq_key, (struct tty_struct *) tty);
1da177e4
LT
24}
25
d2c993d8 26static DECLARE_WORK(ctrlchar_work, ctrlchar_handle_sysrq, NULL);
1da177e4
LT
27#endif
28
29
30/**
31 * Check for special chars at start of input.
32 *
33 * @param buf Console input buffer.
34 * @param len Length of valid data in buffer.
35 * @param tty The tty struct for this console.
36 * @return CTRLCHAR_NONE, if nothing matched,
37 * CTRLCHAR_SYSRQ, if sysrq was encountered
38 * otherwise char to be inserted logically or'ed
39 * with CTRLCHAR_CTRL
40 */
41unsigned int
42ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty)
43{
44 if ((len < 2) || (len > 3))
45 return CTRLCHAR_NONE;
46
47 /* hat is 0xb1 in codepage 037 (US etc.) and thus */
48 /* converted to 0x5e in ascii ('^') */
49 if ((buf[0] != '^') && (buf[0] != '\252'))
50 return CTRLCHAR_NONE;
51
52#ifdef CONFIG_MAGIC_SYSRQ
53 /* racy */
54 if (len == 3 && buf[1] == '-') {
55 ctrlchar_sysrq_key = buf[2];
56 ctrlchar_work.data = tty;
57 schedule_work(&ctrlchar_work);
58 return CTRLCHAR_SYSRQ;
59 }
60#endif
61
62 if (len != 2)
63 return CTRLCHAR_NONE;
64
65 switch (tolower(buf[1])) {
66 case 'c':
67 return INTR_CHAR(tty) | CTRLCHAR_CTRL;
68 case 'd':
69 return EOF_CHAR(tty) | CTRLCHAR_CTRL;
70 case 'z':
71 return SUSP_CHAR(tty) | CTRLCHAR_CTRL;
72 }
73 return CTRLCHAR_NONE;
74}
This page took 0.193423 seconds and 5 git commands to generate.