s390/boot: initialize control registers in decompressor

Partially revert commit 4555b9f34296 ("s390/boot: move
dma sections from decompressor to decompressed kernel").
This is a prerequisite to allow initialization of virtual
memory in decompressor and avoid overwriting of ASCEs in
the decompressed kernel otherwise.

Since the control registers 2, 5 and 15 are reinitialized
in the decompressed kernel again, this change does not
prevent relocating of amode31 section in any way.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/boot/head.S

@@ -317,6 +317,7 @@ SYM_CODE_START_LOCAL(startup_normal)
 	xc	0x300(256),0x300
 	xc	0xe00(256),0xe00
 	xc	0xf00(256),0xf00
+	lctlg	%c0,%c15,.Lctl-.LPG0(%r13)	# load control registers
 	stcke	__LC_BOOT_CLOCK
 	mvc	__LC_LAST_UPDATE_CLOCK(8),__LC_BOOT_CLOCK+1
 	spt	6f-.LPG0(%r13)
@@ -335,6 +336,22 @@ SYM_CODE_END(startup_normal)
 	.quad	0x0000000180000000,startup_pgm_check_handler
 .Lio_new_psw:
 	.quad	0x0002000180000000,0x1f0	# disabled wait
+.Lctl:	.quad	0x04040000		# cr0: AFP registers & secondary space
+	.quad	0			# cr1: primary space segment table
+	.quad	0			# cr2: dispatchable unit control table
+	.quad	0			# cr3: instruction authorization
+	.quad	0xffff			# cr4: instruction authorization
+	.quad	0			# cr5: primary-aste origin
+	.quad	0			# cr6:	I/O interrupts
+	.quad	0			# cr7:	secondary space segment table
+	.quad	0x0000000000008000	# cr8:	access registers translation
+	.quad	0			# cr9:	tracing off
+	.quad	0			# cr10: tracing off
+	.quad	0			# cr11: tracing off
+	.quad	0			# cr12: tracing off
+	.quad	0			# cr13: home space segment table
+	.quad	0xc0000000		# cr14: machine check handling off
+	.quad	0			# cr15: linkage stack operations
 
 #include "head_kdump.S"
 

arch/s390/kernel/head64.S

@@ -20,8 +20,6 @@ __HEAD
 ENTRY(startup_continue)
 	larl	%r1,tod_clock_base
 	mvc	0(16,%r1),__LC_BOOT_CLOCK
-	larl	%r13,.LPG1		# get base
-	lctlg	%c0,%c15,.Lctl-.LPG1(%r13)	# load control registers
 #
 # Setup stack
 #
@@ -42,19 +40,3 @@ ENTRY(startup_continue)
 	.align	16
 .LPG1:
 .Ldw:	.quad	0x0002000180000000,0x0000000000000000
-.Lctl:	.quad	0x04040000		# cr0: AFP registers & secondary space
-	.quad	0			# cr1: primary space segment table
-	.quad	0			# cr2: dispatchable unit control table
-	.quad	0			# cr3: instruction authorization
-	.quad	0xffff			# cr4: instruction authorization
-	.quad	0			# cr5: primary-aste origin
-	.quad	0			# cr6: I/O interrupts
-	.quad	0			# cr7: secondary space segment table
-	.quad	0x0000000000008000	# cr8: access registers translation
-	.quad	0			# cr9: tracing off
-	.quad	0			# cr10: tracing off
-	.quad	0			# cr11: tracing off
-	.quad	0			# cr12: tracing off
-	.quad	0			# cr13: home space segment table
-	.quad	0xc0000000		# cr14: machine check handling off
-	.quad	0			# cr15: linkage stack operations