Commit 79c74ecb authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

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



Switch to the improved update_vsyscall interface that provides
sub-nanosecond precision for gettimeofday and clock_gettime.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 71a86ef0

arch/s390/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -101,7 +101,7 @@ config S390 
	select GENERIC_CPU_DEVICES if !SMP

	select GENERIC_FIND_FIRST_BIT

	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

+3 −2
Original line number Diff line number Diff line
@@ -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

+2 −1
Original line number Diff line number Diff line
@@ -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

+18 −9
Original line number Diff line number Diff line
@@ -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

+16 −14
Original line number Diff line number Diff line
@@ -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