[S390] kdump backend code

This patch provides the architecture specific part of the s390 kdump
support.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 6b99fc3..a9fbd43 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -569,6 +569,16 @@
 	  current kernel, and to start another kernel.  It is like a reboot
 	  but is independent of hardware/microcode support.
 
+config CRASH_DUMP
+	bool "kernel crash dumps"
+	depends on 64BIT
+	help
+	  Generate crash dump after being started by kexec.
+	  Crash dump kernels are loaded in the main kernel with kexec-tools
+	  into a specially reserved region and then later executed after
+	  a crash by kdump/kexec.
+	  For more details see Documentation/kdump/kdump.txt
+
 config ZFCPDUMP
 	def_bool n
 	prompt "zfcpdump support"