[S390] Add PSW restart shutdown trigger

With this patch a new S390 shutdown trigger "restart" is added. If under
z/VM "systerm restart" is entered or under the HMC the "PSW restart" button
is pressed, the PSW located at 0 (31 bit) or 0x1a0 (64 bit) bit is loaded.
Now we execute do_restart() that processes the restart action that is
defined under /sys/firmware/shutdown_actions/on_restart. Currently the
following actions are possible: reipl (default), stop, vmcmd, dump, and
dump_reipl.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index f26280d..e85c911 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -18,6 +18,7 @@
 void pgm_check_handler(void);
 void mcck_int_handler(void);
 void io_int_handler(void);
+void psw_restart_int_handler(void);
 
 #ifdef CONFIG_32BIT
 
@@ -150,7 +151,10 @@
 	 */
 	__u32	ipib;				/* 0x0e00 */
 	__u32	ipib_checksum;			/* 0x0e04 */
-	__u8	pad_0x0e08[0x0f00-0x0e08];	/* 0x0e08 */
+
+	/* 64 bit save area */
+	__u64	save_area_64;			/* 0x0e08 */
+	__u8	pad_0x0e10[0x0f00-0x0e10];	/* 0x0e10 */
 
 	/* Extended facility list */
 	__u64	stfle_fac_list[32];		/* 0x0f00 */
@@ -286,7 +290,10 @@
 	 */
 	__u64	ipib;				/* 0x0e00 */
 	__u32	ipib_checksum;			/* 0x0e08 */
-	__u8	pad_0x0e0c[0x0f00-0x0e0c];	/* 0x0e0c */
+
+	/* 64 bit save area */
+	__u64	save_area_64;			/* 0x0e0c */
+	__u8	pad_0x0e14[0x0f00-0x0e14];	/* 0x0e14 */
 
 	/* Extended facility list */
 	__u64	stfle_fac_list[32];		/* 0x0f00 */
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index d382629..6582f69 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -113,6 +113,7 @@
 
 extern void cmma_init(void);
 extern int memcpy_real(void *, void *, size_t);
+extern void copy_to_absolute_zero(void *dest, void *src, size_t count);
 
 #define finish_arch_switch(prev) do {					     \
 	set_fs(current->thread.mm_segment);				     \