s390/time,vdso: convert to the new update_vsyscall interface

commit 79c74ecb upstream.

Switch to the improved update_vsyscall interface that provides
sub-nanosecond precision for gettimeofday and clock_gettime.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

arch/s390/Kconfig

@@ -100,7 +100,7 @@ config S390
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_CPU_DEVICES if !SMP
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_TIME_VSYSCALL_OLD
+	select GENERIC_TIME_VSYSCALL
 	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 	select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
 	select HAVE_ARCH_SECCOMP_FILTER

arch/s390/include/asm/vdso.h

@@ -26,8 +26,9 @@ struct vdso_data {
 	__u64 wtom_clock_nsec;		/*				0x28 */
 	__u32 tz_minuteswest;		/* Minutes west of Greenwich	0x30 */
 	__u32 tz_dsttime;		/* Type of dst correction	0x34 */
-	__u32 ectg_available;
-	__u32 ntp_mult;			/* NTP adjusted multiplier	0x3C */
+	__u32 ectg_available;		/* ECTG instruction present	0x38 */
+	__u32 tk_mult;			/* Mult. used for xtime_nsec	0x3c */
+	__u32 tk_shift;			/* Shift used for xtime_nsec	0x40 */
 };
 
 struct vdso_per_cpu_data {

arch/s390/kernel/asm-offsets.c

@@ -65,7 +65,8 @@ int main(void)
 	DEFINE(__VDSO_WTOM_NSEC, offsetof(struct vdso_data, wtom_clock_nsec));
 	DEFINE(__VDSO_TIMEZONE, offsetof(struct vdso_data, tz_minuteswest));
 	DEFINE(__VDSO_ECTG_OK, offsetof(struct vdso_data, ectg_available));
-	DEFINE(__VDSO_NTP_MULT, offsetof(struct vdso_data, ntp_mult));
+	DEFINE(__VDSO_TK_MULT, offsetof(struct vdso_data, tk_mult));
+	DEFINE(__VDSO_TK_SHIFT, offsetof(struct vdso_data, tk_shift));
 	DEFINE(__VDSO_ECTG_BASE, offsetof(struct vdso_per_cpu_data, ectg_timer_base));
 	DEFINE(__VDSO_ECTG_USER, offsetof(struct vdso_per_cpu_data, ectg_user_time));
 	/* constants used by the vdso */

arch/s390/kernel/time.c

@@ -221,21 +221,30 @@ struct clocksource * __init clocksource_default_clock(void)
 	return &clocksource_tod;
 }
 
-void update_vsyscall_old(struct timespec *wall_time, struct timespec *wtm,
-			struct clocksource *clock, u32 mult)
+void update_vsyscall(struct timekeeper *tk)
 {
-	if (clock != &clocksource_tod)
+	u64 nsecps;
+
+	if (tk->clock != &clocksource_tod)
 		return;
 
 	/* Make userspace gettimeofday spin until we're done. */
 	++vdso_data->tb_update_count;
 	smp_wmb();
-	vdso_data->xtime_tod_stamp = clock->cycle_last;
-	vdso_data->xtime_clock_sec = wall_time->tv_sec;
-	vdso_data->xtime_clock_nsec = wall_time->tv_nsec;
-	vdso_data->wtom_clock_sec = wtm->tv_sec;
-	vdso_data->wtom_clock_nsec = wtm->tv_nsec;
-	vdso_data->ntp_mult = mult;
+	vdso_data->xtime_tod_stamp = tk->clock->cycle_last;
+	vdso_data->xtime_clock_sec = tk->xtime_sec;
+	vdso_data->xtime_clock_nsec = tk->xtime_nsec;
+	vdso_data->wtom_clock_sec =
+		tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
+	vdso_data->wtom_clock_nsec = tk->xtime_nsec +
+		+ (tk->wall_to_monotonic.tv_nsec << tk->shift);
+	nsecps = (u64) NSEC_PER_SEC << tk->shift;
+	while (vdso_data->wtom_clock_nsec >= nsecps) {
+		vdso_data->wtom_clock_nsec -= nsecps;
+		vdso_data->wtom_clock_sec++;
+	}
+	vdso_data->tk_mult = tk->mult;
+	vdso_data->tk_shift = tk->shift;
 	smp_wmb();
 	++vdso_data->tb_update_count;
 }

arch/s390/kernel/vdso32/clock_gettime.S

@@ -38,25 +38,26 @@ __kernel_clock_gettime:
 	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
 	brc	3,2f
 	ahi	%r0,-1
-2:	ms	%r0,__VDSO_NTP_MULT(%r5)	/* cyc2ns(clock,cycle_delta) */
+2:	ms	%r0,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
 	lr	%r2,%r0
-	l	%r0,__VDSO_NTP_MULT(%r5)
+	l	%r0,__VDSO_TK_MULT(%r5)
 	ltr	%r1,%r1
 	mr	%r0,%r0
 	jnm	3f
-	a	%r0,__VDSO_NTP_MULT(%r5)
+	a	%r0,__VDSO_TK_MULT(%r5)
 3:	alr	%r0,%r2
-	srdl	%r0,12
-	al	%r0,__VDSO_XTIME_NSEC(%r5)	/*  + xtime */
+	al	%r0,__VDSO_XTIME_NSEC(%r5)	/*  + tk->xtime_nsec */
 	al	%r1,__VDSO_XTIME_NSEC+4(%r5)
 	brc	12,4f
 	ahi	%r0,1
-4:	l	%r2,__VDSO_XTIME_SEC+4(%r5)
-	al	%r0,__VDSO_WTOM_NSEC(%r5)	/*  + wall_to_monotonic */
+4:	al	%r0,__VDSO_WTOM_NSEC(%r5)	/*  + wall_to_monotonic.nsec */
 	al	%r1,__VDSO_WTOM_NSEC+4(%r5)
 	brc	12,5f
 	ahi	%r0,1
-5:	al	%r2,__VDSO_WTOM_SEC+4(%r5)
+5:	l	%r2,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
+	srdl	%r0,0(%r2)			/*  >> tk->shift */
+	l	%r2,__VDSO_XTIME_SEC+4(%r5)
+	al	%r2,__VDSO_WTOM_SEC+4(%r5)
 	cl	%r4,__VDSO_UPD_COUNT+4(%r5)	/* check update counter */
 	jne	1b
 	basr	%r5,0
@@ -86,20 +87,21 @@ __kernel_clock_gettime:
 	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
 	brc	3,12f
 	ahi	%r0,-1
-12:	ms	%r0,__VDSO_NTP_MULT(%r5)	/* cyc2ns(clock,cycle_delta) */
+12:	ms	%r0,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
 	lr	%r2,%r0
-	l	%r0,__VDSO_NTP_MULT(%r5)
+	l	%r0,__VDSO_TK_MULT(%r5)
 	ltr	%r1,%r1
 	mr	%r0,%r0
 	jnm	13f
-	a	%r0,__VDSO_NTP_MULT(%r5)
+	a	%r0,__VDSO_TK_MULT(%r5)
 13:	alr	%r0,%r2
-	srdl	%r0,12
-	al	%r0,__VDSO_XTIME_NSEC(%r5)	/*  + xtime */
+	al	%r0,__VDSO_XTIME_NSEC(%r5)	/*  + tk->xtime_nsec */
 	al	%r1,__VDSO_XTIME_NSEC+4(%r5)
 	brc	12,14f
 	ahi	%r0,1
-14:	l	%r2,__VDSO_XTIME_SEC+4(%r5)
+14:	l	%r2,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
+	srdl	%r0,0(%r2)			/*  >> tk->shift */
+	l	%r2,__VDSO_XTIME_SEC+4(%r5)
 	cl	%r4,__VDSO_UPD_COUNT+4(%r5)	/* check update counter */
 	jne	11b
 	basr	%r5,0

arch/s390/kernel/vdso32/gettimeofday.S

@@ -35,15 +35,14 @@ __kernel_gettimeofday:
 	sl	%r1,__VDSO_XTIME_STAMP+4(%r5)
 	brc	3,3f
 	ahi	%r0,-1
-3:	ms	%r0,__VDSO_NTP_MULT(%r5)	/* cyc2ns(clock,cycle_delta) */
+3:	ms	%r0,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
 	st	%r0,24(%r15)
-	l	%r0,__VDSO_NTP_MULT(%r5)
+	l	%r0,__VDSO_TK_MULT(%r5)
 	ltr	%r1,%r1
 	mr	%r0,%r0
 	jnm	4f
-	a	%r0,__VDSO_NTP_MULT(%r5)
+	a	%r0,__VDSO_TK_MULT(%r5)
 4:	al	%r0,24(%r15)
-	srdl	%r0,12
 	al	%r0,__VDSO_XTIME_NSEC(%r5)	/*  + xtime */
 	al	%r1,__VDSO_XTIME_NSEC+4(%r5)
 	brc	12,5f
@@ -51,6 +50,8 @@ __kernel_gettimeofday:
 5:	mvc	24(4,%r15),__VDSO_XTIME_SEC+4(%r5)
 	cl	%r4,__VDSO_UPD_COUNT+4(%r5)	/* check update counter */
 	jne	1b
+	l	%r4,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
+	srdl	%r0,0(%r4)			/*  >> tk->shift */
 	l	%r4,24(%r15)			/* get tv_sec from stack */
 	basr	%r5,0
 6:	ltr	%r0,%r0

arch/s390/kernel/vdso64/clock_gettime.S

@@ -34,14 +34,15 @@ __kernel_clock_gettime:
 	tmll	%r4,0x0001			/* pending update ? loop */
 	jnz	0b
 	stck	48(%r15)			/* Store TOD clock */
+	lgf	%r2,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
+	lg	%r0,__VDSO_XTIME_SEC(%r5)	/* tk->xtime_sec */
+	alg	%r0,__VDSO_WTOM_SEC(%r5)	/*  + wall_to_monotonic.sec */
 	lg	%r1,48(%r15)
 	sg	%r1,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
-	msgf	%r1,__VDSO_NTP_MULT(%r5)	/*  * NTP adjustment */
-	srlg	%r1,%r1,12			/* cyc2ns(clock,cycle_delta) */
-	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + xtime */
-	lg	%r0,__VDSO_XTIME_SEC(%r5)
-	alg	%r1,__VDSO_WTOM_NSEC(%r5)	/*  + wall_to_monotonic */
-	alg	%r0,__VDSO_WTOM_SEC(%r5)
+	msgf	%r1,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
+	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + tk->xtime_nsec */
+	alg	%r1,__VDSO_WTOM_NSEC(%r5)	/*  + wall_to_monotonic.nsec */
+	srlg	%r1,%r1,0(%r2)			/*  >> tk->shift */
 	clg	%r4,__VDSO_UPD_COUNT(%r5)	/* check update counter */
 	jne	0b
 	larl	%r5,13f
@@ -62,12 +63,13 @@ __kernel_clock_gettime:
 	tmll	%r4,0x0001			/* pending update ? loop */
 	jnz	5b
 	stck	48(%r15)			/* Store TOD clock */
+	lgf	%r2,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
 	lg	%r1,48(%r15)
 	sg	%r1,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
-	msgf	%r1,__VDSO_NTP_MULT(%r5)	/*  * NTP adjustment */
-	srlg	%r1,%r1,12			/* cyc2ns(clock,cycle_delta) */
-	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + xtime */
-	lg	%r0,__VDSO_XTIME_SEC(%r5)
+	msgf	%r1,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
+	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + tk->xtime_nsec */
+	srlg	%r1,%r1,0(%r2)			/*  >> tk->shift */
+	lg	%r0,__VDSO_XTIME_SEC(%r5)	/* tk->xtime_sec */
 	clg	%r4,__VDSO_UPD_COUNT(%r5)	/* check update counter */
 	jne	5b
 	larl	%r5,13f

arch/s390/kernel/vdso64/gettimeofday.S

@@ -31,12 +31,13 @@ __kernel_gettimeofday:
 	stck	48(%r15)			/* Store TOD clock */
 	lg	%r1,48(%r15)
 	sg	%r1,__VDSO_XTIME_STAMP(%r5)	/* TOD - cycle_last */
-	msgf	%r1,__VDSO_NTP_MULT(%r5)	/*  * NTP adjustment */
-	srlg	%r1,%r1,12			/* cyc2ns(clock,cycle_delta) */
-	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + xtime.tv_nsec */
-	lg	%r0,__VDSO_XTIME_SEC(%r5)	/* xtime.tv_sec */
+	msgf	%r1,__VDSO_TK_MULT(%r5)		/*  * tk->mult */
+	alg	%r1,__VDSO_XTIME_NSEC(%r5)	/*  + tk->xtime_nsec */
+	lg	%r0,__VDSO_XTIME_SEC(%r5)	/* tk->xtime_sec */
 	clg	%r4,__VDSO_UPD_COUNT(%r5)	/* check update counter */
 	jne	0b
+	lgf	%r5,__VDSO_TK_SHIFT(%r5)	/* Timekeeper shift */
+	srlg	%r1,%r1,0(%r5)			/*  >> tk->shift */
 	larl	%r5,5f
 2:	clg	%r1,0(%r5)
 	jl	3f