Commit 94ecbf1e authored by Sven Schnelle's avatar Sven Schnelle Committed by Alexander Gordeev
Browse files

s390/time: Remove in-kernel time steering 



Remove the in-kernel time steering in favour of the new
ptp s390 driver, which allows the kernel clock to be steered
more precise.

Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent 925f0707

arch/s390/include/asm/vdso/gettimeofday.h

+1 −7
Original line number Diff line number Diff line
@@ -16,13 +16,7 @@ 


static inline u64 __arch_get_hw_counter(s32 clock_mode, const struct vdso_time_data *vd)

{

	u64 adj, now;



	now = get_tod_clock();

	adj = vd->arch_data.tod_steering_end - now;

	if (unlikely((s64) adj > 0))

		now += (vd->arch_data.tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15);

	return now;

	return get_tod_clock() - vd->arch_data.tod_delta;

}



static __always_inline

arch/s390/include/asm/vdso/time_data.h

+1 −2
Original line number Diff line number Diff line
@@ -5,8 +5,7 @@ 
#include <linux/types.h>



struct arch_vdso_time_data {

	__s64 tod_steering_delta;

	__u64 tod_steering_end;

	__s64 tod_delta;

};



#endif /* __S390_ASM_VDSO_TIME_DATA_H */

arch/s390/kernel/time.c

+3 −36
Original line number Diff line number Diff line
@@ -69,8 +69,6 @@ unsigned char ptff_function_mask[16]; 


static unsigned long lpar_offset;

static unsigned long initial_leap_seconds;

static unsigned long tod_steering_end;

static long tod_steering_delta;



/*

 * Get time offsets with PTFF
@@ -80,9 +78,7 @@ void __init time_early_init(void) 
	struct ptff_qto qto;

	struct ptff_qui qui;



	/* Initialize TOD steering parameters */

	tod_steering_end = tod_clock_base.tod;

	vdso_k_time_data->arch_data.tod_steering_end = tod_steering_end;

	vdso_k_time_data->arch_data.tod_delta = tod_clock_base.tod;



	if (!test_facility(28))

		return;
@@ -226,21 +222,7 @@ void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time, 


static u64 read_tod_clock(struct clocksource *cs)

{

	unsigned long now, adj;



	preempt_disable(); /* protect from changes to steering parameters */

	now = get_tod_clock();

	adj = tod_steering_end - now;

	if (unlikely((s64) adj > 0))

		/*

		 * manually steer by 1 cycle every 2^16 cycles. This

		 * corresponds to shifting the tod delta by 15. 1s is

		 * therefore steered in ~9h. The adjust will decrease

		 * over time, until it finally reaches 0.

		 */

		now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15);

	preempt_enable();

	return now;

	return get_tod_clock_monotonic();

}



static struct clocksource clocksource_tod = {
@@ -369,26 +351,11 @@ static inline int check_sync_clock(void) 
 */

static void clock_sync_global(long delta)

{

	unsigned long now, adj;

	struct ptff_qto qto;



	/* Fixup the monotonic sched clock. */

	tod_clock_base.eitod += delta;

	/* Adjust TOD steering parameters. */

	now = get_tod_clock();

	adj = tod_steering_end - now;

	if (unlikely((s64) adj >= 0))

		/* Calculate how much of the old adjustment is left. */

		tod_steering_delta = (tod_steering_delta < 0) ?

			-(adj >> 15) : (adj >> 15);

	tod_steering_delta += delta;

	if ((abs(tod_steering_delta) >> 48) != 0)

		panic("TOD clock sync offset %li is too large to drift\n",

		      tod_steering_delta);

	tod_steering_end = now + (abs(tod_steering_delta) << 15);

	vdso_k_time_data->arch_data.tod_steering_end = tod_steering_end;

	vdso_k_time_data->arch_data.tod_steering_delta = tod_steering_delta;



	vdso_k_time_data->arch_data.tod_delta = tod_clock_base.tod;

	/* Update LPAR offset. */

	if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)

		lpar_offset = qto.tod_epoch_difference;