[PATCH] s390: diag 0x308 reipl

Add code to support the re-IPL method using diagnose 0x308.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/s390/kernel/reipl_diag.c b/arch/s390/kernel/reipl_diag.c
new file mode 100644
index 0000000..83cb42b
--- /dev/null
+++ b/arch/s390/kernel/reipl_diag.c
@@ -0,0 +1,39 @@
+/*
+ * This file contains the implementation of the
+ * Linux re-IPL support
+ *
+ * (C) Copyright IBM Corp. 2005
+ *
+ * Author(s): Volker Sameske (sameske@de.ibm.com)
+ *
+ */
+
+#include <linux/kernel.h>
+
+static unsigned int reipl_diag_rc1;
+static unsigned int reipl_diag_rc2;
+
+/*
+ * re-IPL the system using the last used IPL parameters
+ */
+void reipl_diag(void)
+{
+        asm volatile (
+		"   la   %%r4,0\n"
+		"   la   %%r5,0\n"
+                "   diag %%r4,%2,0x308\n"
+                "0:\n"
+		"   st   %%r4,%0\n"
+		"   st   %%r5,%1\n"
+                ".section __ex_table,\"a\"\n"
+#ifdef __s390x__
+                "   .align 8\n"
+                "   .quad 0b, 0b\n"
+#else
+                "   .align 4\n"
+                "   .long 0b, 0b\n"
+#endif
+                ".previous\n"
+                : "=m" (reipl_diag_rc1), "=m" (reipl_diag_rc2)
+		: "d" (3) : "cc", "4", "5" );
+}