Commit 385bf43c authored by Vasily Gorbik's avatar Vasily Gorbik
Browse files

s390/entry: rely on long-displacement facility 



Since commit 4efd417f ("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: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent f62f8b71

arch/s390/kernel/entry.S

+3 −5
Original line number Diff line number Diff line
@@ -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