From 385bf43c48ffe44af881039779a6be09ac8a77c8 Mon Sep 17 00:00:00 2001
From: Vasily Gorbik <gor@linux.ibm.com>
Date: Tue, 28 Mar 2023 11:09:09 +0200
Subject: [PATCH] s390/entry: rely on long-displacement facility
Since commit 4efd417f298b ("s390: raise minimum supported machine
generation to z10"), the long-displacement facility is assumed and
required for the kernel. Clean up a couple of places in the entry code,
where long-displacement could be used directly instead of using a base
register.
However, there are still a few other places where a base register has
to be used to extend short-displacement for the second lowcore page
access. Notably, boot/head.S still has to be built for z900, and in
mcck_int_handler, spt and lbear, which don't have long-displacements,
but need to access save areas at the second lowcore page.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
arch/s390/kernel/entry.S | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 58b85aedca22d..c41ec5a03d07a 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -489,14 +489,13 @@ ENTRY(mcck_int_handler)
la %r1,4095 # validate r1
spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # validate cpu timer
LBEAR __LC_LAST_BREAK_SAVE_AREA-4095(%r1) # validate bear
- lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# validate gprs
+ lmg %r0,%r15,__LC_GPREGS_SAVE_AREA # validate gprs
lmg %r8,%r9,__LC_MCK_OLD_PSW
TSTMSK __LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
jo .Lmcck_panic # yes -> rest of mcck code invalid
TSTMSK __LC_MCCK_CODE,MCCK_CODE_CR_VALID
jno .Lmcck_panic # control registers invalid -> panic
- la %r14,4095
- lctlg %c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r14) # validate ctl regs
+ lctlg %c0,%c15,__LC_CREGS_SAVE_AREA # validate ctl regs
ptlb
lghi %r14,__LC_CPU_TIMER_SAVE_AREA
mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
@@ -594,8 +593,7 @@ ENTRY(restart_int_handler)
stg %r15,__LC_SAVE_AREA_RESTART
TSTMSK __LC_RESTART_FLAGS,RESTART_FLAG_CTLREGS,4
jz 0f
- la %r15,4095
- lctlg %c0,%c15,__LC_CREGS_SAVE_AREA-4095(%r15)
+ lctlg %c0,%c15,__LC_CREGS_SAVE_AREA
0: larl %r15,.Lstosm_tmp
stosm 0(%r15),0x04 # turn dat on, keep irqs off
lg %r15,__LC_RESTART_STACK
--
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