[S390] s390: hibernation support for s390

This patch introduces the hibernation backend support to the
s390 architecture. Now it is possible to suspend a mainframe Linux
guest using the following command:

echo disk > /sys/power/state

Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/suspend.h

@@ -0,0 +1,10 @@
+#ifndef __ASM_S390_SUSPEND_H
+#define __ASM_S390_SUSPEND_H
+
+static inline int arch_prepare_suspend(void)
+{
+	return 0;
+}
+
+#endif
+

arch/s390/include/asm/system.h

@@ -1,11 +1,7 @@
 /*
- *  include/asm-s390/system.h
+ * Copyright IBM Corp. 1999, 2009
  *
- *  S390 version
- *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
- *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
- *
- *  Derived from "include/asm-i386/system.h"
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
 #ifndef __ASM_SYSTEM_H
@@ -469,6 +465,20 @@ extern psw_t sysc_restore_trace_psw;
 extern psw_t io_restore_trace_psw;
 #endif
 
+static inline int tprot(unsigned long addr)
+{
+	int rc = -EFAULT;
+
+	asm volatile(
+		"	tprot	0(%1),0\n"
+		"0:	ipm	%0\n"
+		"	srl	%0,28\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "+d" (rc) : "a" (addr) : "cc");
+	return rc;
+}
+
 #endif /* __KERNEL__ */
 
 #endif