Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / s390 / char / ctrlchar.c

diff --git a/kernel/drivers/s390/char/ctrlchar.c b/kernel/drivers/s390/char/ctrlchar.c
new file mode 100644 (file)
index 0000000..8de2deb
--- /dev/null
+++ b/kernel/drivers/s390/char/ctrlchar.c
@@ -0,0 +1,72 @@
+/*
+ *  Unified handling of special chars.
+ *
+ *    Copyright IBM Corp. 2001
+ *    Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
+ *
+ */
+
+#include <linux/stddef.h>
+#include <asm/errno.h>
+#include <linux/sysrq.h>
+#include <linux/ctype.h>
+
+#include "ctrlchar.h"
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static int ctrlchar_sysrq_key;
+
+static void
+ctrlchar_handle_sysrq(struct work_struct *work)
+{
+       handle_sysrq(ctrlchar_sysrq_key);
+}
+
+static DECLARE_WORK(ctrlchar_work, 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 CTRLCHAR_NONE, if nothing matched,
+ *         CTRLCHAR_SYSRQ, if sysrq was encountered
+ *         otherwise char to be inserted logically or'ed
+ *         with CTRLCHAR_CTRL
+ */
+unsigned int
+ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty)
+{
+       if ((len < 2) || (len > 3))
+               return CTRLCHAR_NONE;
+
+       /* hat is 0xb1 in codepage 037 (US etc.) and thus */
+       /* converted to 0x5e in ascii ('^') */
+       if ((buf[0] != '^') && (buf[0] != '\252'))
+               return CTRLCHAR_NONE;
+
+#ifdef CONFIG_MAGIC_SYSRQ
+       /* racy */
+       if (len == 3 && buf[1] == '-') {
+               ctrlchar_sysrq_key = buf[2];
+               schedule_work(&ctrlchar_work);
+               return CTRLCHAR_SYSRQ;
+       }
+#endif
+
+       if (len != 2)
+               return CTRLCHAR_NONE;
+
+       switch (tolower(buf[1])) {
+       case 'c':
+               return INTR_CHAR(tty) | CTRLCHAR_CTRL;
+       case 'd':
+               return EOF_CHAR(tty)  | CTRLCHAR_CTRL;
+       case 'z':
+               return SUSP_CHAR(tty) | CTRLCHAR_CTRL;
+       }
+       return CTRLCHAR_NONE;
+}