Commit e259b3fa authored by Sven Schnelle's avatar Sven Schnelle Committed by Heiko Carstens
Browse files

s390/idle: add missing mt_cycles calculation 



During removal of the critical section cleanup the calculation
of mt_cycles during idle was removed. This causes invalid
accounting on systems with SMT enabled.

Fixes: 0b0ed657 ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 7a84ffc0

arch/s390/kernel/entry.S

+25 −9
Original line number Diff line number Diff line
@@ -118,7 +118,7 @@ _LPP_OFFSET = __LC_LPP 


	.macro	SWITCH_ASYNC savearea,timer

	tmhh	%r8,0x0001		# interrupting from user ?

	jnz	2f

	jnz	4f

#if IS_ENABLED(CONFIG_KVM)

	lgr	%r14,%r9

	larl	%r13,.Lsie_gmap
@@ -131,9 +131,25 @@ _LPP_OFFSET = __LC_LPP 
#endif

0:	larl	%r13,.Lpsw_idle_exit

	cgr	%r13,%r9

	jne	1f

	jne	3f



	mvc	__CLOCK_IDLE_EXIT(8,%r2), __LC_INT_CLOCK

	larl	%r1,smp_cpu_mtid

	llgf	%r1,0(%r1)

	ltgr	%r1,%r1

	jz	2f			# no SMT, skip mt_cycles calculation

	.insn	rsy,0xeb0000000017,%r1,5,__SF_EMPTY+80(%r15)

	larl	%r3,mt_cycles

	ag	%r3,__LC_PERCPU_OFFSET

	la	%r4,__SF_EMPTY+16(%r15)

1:	lg	%r0,0(%r3)

	slg	%r0,0(%r4)

	alg	%r0,64(%r4)

	stg	%r0,0(%r3)

	la	%r3,8(%r3)

	la	%r4,8(%r4)

	brct	%r1,1b



2:	mvc	__CLOCK_IDLE_EXIT(8,%r2), __LC_INT_CLOCK

	mvc	__TIMER_IDLE_EXIT(8,%r2), __LC_ASYNC_ENTER_TIMER

	# account system time going idle

	ni	__LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
@@ -152,17 +168,17 @@ _LPP_OFFSET = __LC_LPP 
	mvc	__LC_LAST_UPDATE_TIMER(8),__TIMER_IDLE_EXIT(%r2)



	nihh	%r8,0xfcfd		# clear wait state and irq bits

1:	lg	%r14,__LC_ASYNC_STACK	# are we already on the target stack?

3:	lg	%r14,__LC_ASYNC_STACK	# are we already on the target stack?

	slgr	%r14,%r15

	srag	%r14,%r14,STACK_SHIFT

	jnz	3f

	jnz	5f

	CHECK_STACK \savearea

	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)

	j	4f

2:	UPDATE_VTIME %r14,%r15,\timer

	j	6f

4:	UPDATE_VTIME %r14,%r15,\timer

	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP

3:	lg	%r15,__LC_ASYNC_STACK	# load async stack

4:	la	%r11,STACK_FRAME_OVERHEAD(%r15)

5:	lg	%r15,__LC_ASYNC_STACK	# load async stack

6:	la	%r11,STACK_FRAME_OVERHEAD(%r15)

	.endm



	.macro UPDATE_VTIME w1,w2,enter_timer