From c2313594216b3fde9559e502bb36d14e9d601a56 Mon Sep 17 00:00:00 2001
From: Vasily Gorbik <gor@linux.ibm.com>
Date: Thu, 14 Nov 2019 14:08:28 +0100
Subject: [PATCH] s390/early: move access registers setup in C code

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
 arch/s390/kernel/early.c  |  9 +++++++++
 arch/s390/kernel/head64.S | 10 ++--------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 0ed6ae6a8bde..db32a55daaec 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -30,6 +30,7 @@
 #include <asm/sclp.h>
 #include <asm/facility.h>
 #include <asm/boot_data.h>
+#include <asm/switch_to.h>
 #include "entry.h"
 
 static void __init reset_tod_clock(void)
@@ -271,6 +272,13 @@ static inline void setup_control_registers(void)
 	__ctl_load(reg, 0, 0);
 }
 
+static inline void setup_access_registers(void)
+{
+	unsigned int acrs[NUM_ACRS] = { 0 };
+
+	restore_access_regs(acrs);
+}
+
 static int __init disable_vector_extension(char *str)
 {
 	S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
@@ -329,5 +337,6 @@ void __init startup_init(void)
 	setup_topology();
 	sclp_early_detect();
 	setup_control_registers();
+	setup_access_registers();
 	lockdep_on();
 }
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index 9d649abddffd..b9e585f528a6 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -35,13 +35,8 @@ ENTRY(startup_continue)
 #ifdef CONFIG_KASAN
 	brasl	%r14,kasan_early_init
 #endif
-#
-# Early machine initialization and detection functions.
-#
-	brasl	%r14,startup_init
-
-	lam	0,15,.Laregs-.LPG1(%r13)	# load acrs needed by uaccess
-	brasl	%r14,start_kernel		# go to C code
+	brasl	%r14,startup_init		# s390 specific early init
+	brasl	%r14,start_kernel		# common init code
 #
 # We returned from start_kernel ?!? PANIK
 #
@@ -51,4 +46,3 @@ ENTRY(startup_continue)
 	.align	16
 .LPG1:
 .Ldw:	.quad	0x0002000180000000,0x0000000000000000
-.Laregs:.long	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0