s390/vmcore: use vmcore for zfcpdump

Modify the s390 copy_oldmem_page() and remap_oldmem_pfn_range() function
for zfcpdump to read from the HSA memory if memory below HSA_SIZE bytes is
requested.  Otherwise real memory is used.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index fb2723e..3ec2728 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -526,6 +526,7 @@
 	bool "kernel crash dumps"
 	depends on 64BIT && SMP
 	select KEXEC
+	select ZFCPDUMP
 	help
 	  Generate crash dump after being started by kexec.
 	  Crash dump kernels are loaded in the main kernel with kexec-tools
@@ -536,7 +537,7 @@
 config ZFCPDUMP
 	def_bool n
 	prompt "zfcpdump support"
-	select SMP
+	depends on SMP
 	help
 	  Select this option if you want to build an zfcpdump enabled kernel.
 	  Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.