patch-2.4.10 linux/include/linux/sysrq.h

• Lines: 92
• Date: Mon Sep 17 22:52:35 2001
• Orig file: v2.4.9/linux/include/linux/sysrq.h
• Orig date: Tue Aug 7 12:48:42 2001

diff -u --recursive --new-file v2.4.9/linux/include/linux/sysrq.h linux/include/linux/sysrq.h
@@ -5,6 +5,10 @@
  *	Linux Magic System Request Key Hacks
  *
  *	(c) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ *
+ *	(c) 2000 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
+ *	overhauled to use key registration
+ *	based upon discusions in irc://irc.openprojects.net/#kernelnewbies
  */
 
 #include <linux/config.h>
@@ -13,12 +17,79 @@
 struct kbd_struct;
 struct tty_struct;
 
+struct sysrq_key_op {
+	void (*handler)(int, struct pt_regs *,
+			struct kbd_struct *, struct tty_struct *);
+	char *help_msg;
+	char *action_msg;
+};
+
 /* Generic SysRq interface -- you may call it from any device driver, supplying
  * ASCII code of the key, pointer to registers and kbd/tty structs (if they
  * are available -- else NULL's).
  */
 
-void handle_sysrq(int, struct pt_regs *, struct kbd_struct *, struct tty_struct *);
+void handle_sysrq(int, struct pt_regs *,
+		struct kbd_struct *, struct tty_struct *);
+
+
+/* 
+ * Nonlocking version of handle sysrq, used by sysrq handlers that need to
+ * call sysrq handlers
+ */
+
+void __handle_sysrq_nolock(int, struct pt_regs *,
+                struct kbd_struct *, struct tty_struct *);
+
+
+#ifdef CONFIG_MAGIC_SYSRQ
+
+/*
+ * Sysrq registration manipulation functions
+ */
+
+void __sysrq_lock_table (void);
+void __sysrq_unlock_table (void);
+struct sysrq_key_op *__sysrq_get_key_op (int key);
+void __sysrq_put_key_op (int key, struct sysrq_key_op *op_p);
+
+extern __inline__ int
+__sysrq_swap_key_ops_nolock(int key, struct sysrq_key_op *insert_op_p,
+				struct sysrq_key_op *remove_op_p) {
+	int retval;
+	if (__sysrq_get_key_op(key) == remove_op_p) {
+		__sysrq_put_key_op(key, insert_op_p);
+		retval = 0;
+	} else {
+                retval = -1;
+	}
+	return retval;
+}
+
+extern __inline__ int
+__sysrq_swap_key_ops(int key, struct sysrq_key_op *insert_op_p,
+				struct sysrq_key_op *remove_op_p) {
+	int retval;
+	__sysrq_lock_table();
+	retval = __sysrq_swap_key_ops_nolock(key, insert_op_p, remove_op_p);
+	__sysrq_unlock_table();
+	return retval;
+}
+	
+static inline int register_sysrq_key(int key, struct sysrq_key_op *op_p)
+{
+	return __sysrq_swap_key_ops(key, op_p, NULL);
+}
+
+static inline int unregister_sysrq_key(int key, struct sysrq_key_op *op_p)
+{
+	return __sysrq_swap_key_ops(key, NULL, op_p);
+}
+
+#else
+#define register_sysrq_key(a,b)		do {} while(0)
+#define unregister_sysrq_key(a,b)	do {} while(0)
+#endif
 
 /* Deferred actions */