patch-2.4.4 linux/drivers/s390/char/ctrlchar.c

• Lines: 97
• Date: Wed Apr 11 19:02:29 2001
• Orig file: v2.4.3/linux/drivers/s390/char/ctrlchar.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.3/linux/drivers/s390/char/ctrlchar.c linux/drivers/s390/char/ctrlchar.c
@@ -0,0 +1,96 @@
+/*
+ *  drivers/s390/char/controlchar.c
+ *  Unified handling of special chars.
+ *
+ *    Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/tty.h>
+#include <linux/interrupt.h>
+
+#include <linux/sysrq.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/delay.h>
+#include <asm/cpcmd.h>
+#include <asm/irq.h>
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static int ctrlchar_sysrq_key;
+static struct tq_struct ctrlchar_tq;
+
+static void
+ctrlchar_handle_sysrq(struct tty_struct *tty) {
+	handle_sysrq(ctrlchar_sysrq_key, NULL, NULL, tty);
+}
+#endif
+
+void ctrlchar_init(void) {
+#ifdef CONFIG_MAGIC_SYSRQ
+	static int init_done = 0;
+
+	if (init_done++)
+		return;
+	INIT_LIST_HEAD(&ctrlchar_tq.list);
+	ctrlchar_tq.sync = 0;
+	ctrlchar_tq.routine = ctrlchar_handle_sysrq;
+#endif
+}
+
+/**
+ * Check for special chars at start of input.
+ *
+ * @param buf Console input buffer.
+ * @param len Length of valid data in buffer.
+ * @param tty The tty struct for this console.
+ * @return NULL, if nothing matched, (char *)-1, if buffer contents
+ *         should be ignored, otherwise pointer to char to be inserted.
+ */
+char *ctrlchar_handle(const char *buf, int len, struct tty_struct *tty) {
+
+	static char ret;
+
+	if ((len < 2) || (len > 3))
+		return NULL;
+	/* hat is 0xb1 in codepage 037 (US etc.) and thus */
+	/* converted to 0x5e in ascii ('^') */
+	if ((buf[0] != '^') && (buf[0] != '\252'))
+		return NULL;
+	switch (buf[1]) {
+#ifdef CONFIG_MAGIC_SYSRQ
+		case '-':
+			if (len == 3) {
+				ctrlchar_sysrq_key = buf[2];
+				ctrlchar_tq.data = tty;
+				queue_task(&ctrlchar_tq, &tq_immediate);
+				mark_bh(IMMEDIATE_BH);
+				return (char *)-1;
+			}
+			break;
+#endif
+		case 'c':
+			if (len == 2) {
+				ret = INTR_CHAR(tty);
+				return &ret;
+			}
+			break;
+		case 'd':
+			if (len == 2) {
+				ret = EOF_CHAR(tty);
+				return &ret;
+			}
+			break;
+		case 'z':
+			if (len == 2) {
+				ret = SUSP_CHAR(tty);
+				return &ret;
+			}
+			break;
+	}
+	return NULL;
+}