s390/vdso: replace stck with stcke

If gettimeofday / clock_gettime are called multiple times in a row
the STCK instruction will stall until a difference in the result is
visible. This unnecessarily slows down the vdso calls, use stcke
instead of stck to get rid of the stall.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/vdso32/clock_gettime.S

@@ -30,8 +30,8 @@ __kernel_clock_gettime:
 1:	l	%r4,__VDSO_UPD_COUNT+4(%r5)	/* load update counter */
 	tml	%r4,0x0001			/* pending update ? loop */
 	jnz	1b
-	stck	24(%r15)			/* Store TOD clock */
-	lm	%r0,%r1,24(%r15)
+	stcke	24(%r15)			/* Store TOD clock */
+	lm	%r0,%r1,25(%r15)
 	s	%r0,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
 	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
 	brc	3,2f
@@ -72,8 +72,8 @@ __kernel_clock_gettime:
 11:	l	%r4,__VDSO_UPD_COUNT+4(%r5)	/* load update counter */
 	tml	%r4,0x0001			/* pending update ? loop */
 	jnz	11b
-	stck	24(%r15)			/* Store TOD clock */
-	lm	%r0,%r1,24(%r15)
+	stcke	24(%r15)			/* Store TOD clock */
+	lm	%r0,%r1,25(%r15)
 	s	%r0,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
 	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
 	brc	3,12f

arch/s390/kernel/vdso32/gettimeofday.S

@@ -29,8 +29,8 @@ __kernel_gettimeofday:
 	l	%r4,__VDSO_UPD_COUNT+4(%r5)	/* load update counter */
 	tml	%r4,0x0001			/* pending update ? loop */
 	jnz	1b
-	stck	24(%r15)			/* Store TOD clock */
-	lm	%r0,%r1,24(%r15)
+	stcke	24(%r15)			/* Store TOD clock */
+	lm	%r0,%r1,25(%r15)
 	s	%r0,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
 	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
 	brc	3,3f

arch/s390/kernel/vdso64/clock_gettime.S

@@ -33,10 +33,10 @@ __kernel_clock_gettime:
 0:	lg	%r4,__VDSO_UPD_COUNT(%r5)	/* load update counter */
 	tmll	%r4,0x0001			/* pending update ? loop */
 	jnz	0b
-	stck	48(%r15)			/* Store TOD clock */
+	stcke	48(%r15)			/* Store TOD clock */
 	lgf	%r2,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
 	lg	%r0,__VDSO_WTOM_SEC(%r5)
-	lg	%r1,48(%r15)
+	lg	%r1,49(%r15)
 	sg	%r1,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
 	msgf	%r1,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
 	alg	%r1,__VDSO_WTOM_NSEC(%r5)
@@ -58,9 +58,9 @@ __kernel_clock_gettime:
 5:	lg	%r4,__VDSO_UPD_COUNT(%r5)	/* load update counter */
 	tmll	%r4,0x0001			/* pending update ? loop */
 	jnz	5b
-	stck	48(%r15)			/* Store TOD clock */
+	stcke	48(%r15)			/* Store TOD clock */
 	lgf	%r2,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
-	lg	%r1,48(%r15)
+	lg	%r1,49(%r15)
 	sg	%r1,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
 	msgf	%r1,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
 	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + tk->xtime_nsec */

arch/s390/kernel/vdso64/gettimeofday.S

@@ -28,8 +28,8 @@ __kernel_gettimeofday:
 	lg	%r4,__VDSO_UPD_COUNT(%r5)	/* load update counter */
 	tmll	%r4,0x0001			/* pending update ? loop */
 	jnz	0b
-	stck	48(%r15)			/* Store TOD clock */
-	lg	%r1,48(%r15)
+	stcke	48(%r15)			/* Store TOD clock */
+	lg	%r1,49(%r15)
 	sg	%r1,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
 	msgf	%r1,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
 	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + tk->xtime_nsec */