Commit b0d31159 authored by Sven Schnelle's avatar Sven Schnelle Committed by Vasily Gorbik
Browse files

s390: open code SWITCH_KERNEL macro 



This is a preparation patch for two later bugfixes. In the past both
int_handler and machine check handler used SWITCH_KERNEL to switch to
the kernel stack. However, SWITCH_KERNEL doesn't work properly in machine
check context. So instead of adding more complexity to this macro, just
remove it.

Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Cc: <stable@kernel.org> # v5.8+
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 1c767347

arch/s390/kernel/entry.S

+46 −28
Original line number Diff line number Diff line
@@ -81,32 +81,6 @@ _LPP_OFFSET = __LC_LPP 
#endif

	.endm



	.macro	SWITCH_KERNEL savearea

	tmhh	%r8,0x0001		# interrupting from user ?

	jnz	1f

#if IS_ENABLED(CONFIG_KVM)

	lgr	%r14,%r9

	larl	%r13,.Lsie_gmap

	slgr	%r14,%r13

	lghi	%r13,.Lsie_done - .Lsie_gmap

	clgr	%r14,%r13

	jhe	0f

	lghi	%r11,\savearea		# inside critical section, do cleanup

	brasl	%r14,.Lcleanup_sie

#endif

0:	CHECK_STACK \savearea

	lgr	%r11,%r15

	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)

	stg	%r11,__SF_BACKCHAIN(%r15)

	j	2f

1:	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP

	lctlg	%c1,%c1,__LC_KERNEL_ASCE

	lg	%r15,__LC_KERNEL_STACK

	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)

2:	la	%r11,STACK_FRAME_OVERHEAD(%r15)

	.endm



	# Use STORE CLOCK by default, switch to STORE CLOCK FAST if available.

	.macro STCK savearea

	ALTERNATIVE ".insn	s,0xb2050000,\savearea", \

		    ".insn	s,0xb27c0000,\savearea", 25
@@ -413,7 +387,28 @@ ENTRY(\name) 
	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC

	lg	%r12,__LC_CURRENT

	lmg	%r8,%r9,\lc_old_psw

	SWITCH_KERNEL __LC_SAVE_AREA_ASYNC

	tmhh	%r8,0x0001			# interrupting from user ?

	jnz	1f

#if IS_ENABLED(CONFIG_KVM)

	lgr	%r14,%r9

	larl	%r13,.Lsie_gmap

	slgr	%r14,%r13

	lghi	%r13,.Lsie_done - .Lsie_gmap

	clgr	%r14,%r13

	jhe	0f

	lghi	%r11,__LC_SAVE_AREA_ASYNC	# inside critical section, do cleanup

	brasl	%r14,.Lcleanup_sie

#endif

0:	CHECK_STACK __LC_SAVE_AREA_ASYNC

	lgr	%r11,%r15

	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)

	stg	%r11,__SF_BACKCHAIN(%r15)

	j	2f

1:	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP

	lctlg	%c1,%c1,__LC_KERNEL_ASCE

	lg	%r15,__LC_KERNEL_STACK

	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)

2:	la	%r11,STACK_FRAME_OVERHEAD(%r15)

	stmg	%r0,%r7,__PT_R0(%r11)

	# clear user controlled registers to prevent speculative use

	xgr	%r0,%r0
@@ -542,7 +537,30 @@ ENTRY(mcck_int_handler) 
	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID

	jno	.Lmcck_panic

4:	ssm	__LC_PGM_NEW_PSW	# turn dat on, keep irqs off

	SWITCH_KERNEL __LC_GPREGS_SAVE_AREA+64

	tmhh	%r8,0x0001			# interrupting from user ?

	jnz	.Lmcck_user

#if IS_ENABLED(CONFIG_KVM)

	lgr	%r14,%r9

	larl	%r13,.Lsie_gmap

	slgr	%r14,%r13

	lghi	%r13,.Lsie_done - .Lsie_gmap

	clgr	%r14,%r13

	jhe	.Lmcck_stack

	lghi	%r11,__LC_GPREGS_SAVE_AREA+64	# inside critical section, do cleanup

	brasl	%r14,.Lcleanup_sie

.Lmcck_stack:

#endif

	CHECK_STACK __LC_GPREGS_SAVE_AREA+64

	lgr	%r11,%r15

	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)

	stg	%r11,__SF_BACKCHAIN(%r15)

	j	5f

.Lmcck_user:

	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP

	lctlg	%c1,%c1,__LC_KERNEL_ASCE

	lg	%r15,__LC_KERNEL_STACK

	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)

5:	la	%r11,STACK_FRAME_OVERHEAD(%r15)

.Lmcck_skip:

	lghi	%r14,__LC_GPREGS_SAVE_AREA+64

	stmg	%r0,%r7,__PT_R0(%r11)