Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit dc64bef5 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[S390] Use CONFIG_GENERIC_TIME and define TOD clock source. 



Fix too slow clock by using CONFIG_GENERIC_TIME and adding a
clock source for the s390 time-of-day clock. As added benefit
we get rid of the s390 specific definition of do_gettimeofday
and do_settimeofday.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 2033b0c3

arch/s390/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -30,6 +30,9 @@ config GENERIC_CALIBRATE_DELAY 
	bool

	default y



config GENERIC_TIME

	def_bool y



config GENERIC_BUST_SPINLOCK

	bool

arch/s390/defconfig

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ CONFIG_STACKTRACE_SUPPORT=y 
CONFIG_RWSEM_XCHGADD_ALGORITHM=y

CONFIG_GENERIC_HWEIGHT=y

CONFIG_GENERIC_CALIBRATE_DELAY=y

CONFIG_GENERIC_TIME=y

CONFIG_S390=y

CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"

arch/s390/kernel/time.c

+20 −68
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/profile.h>

#include <linux/timex.h>

#include <linux/notifier.h>

#include <linux/clocksource.h>



#include <asm/uaccess.h>

#include <asm/delay.h>
@@ -82,74 +83,6 @@ void tod_to_timeval(__u64 todval, struct timespec *xtime) 
	xtime->tv_nsec = ((todval * 1000) >> 12);

}



static inline unsigned long do_gettimeoffset(void) 

{

	__u64 now;



	now = (get_clock() - jiffies_timer_cc) >> 12;

	now -= (__u64) jiffies * USECS_PER_JIFFY;

	return (unsigned long) now;

}



/*

 * This version of gettimeofday has microsecond resolution.

 */

void do_gettimeofday(struct timeval *tv)

{

	unsigned long flags;

	unsigned long seq;

	unsigned long usec, sec;



	do {

		seq = read_seqbegin_irqsave(&xtime_lock, flags);



		sec = xtime.tv_sec;

		usec = xtime.tv_nsec / 1000 + do_gettimeoffset();

	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));



	while (usec >= 1000000) {

		usec -= 1000000;

		sec++;

	}



	tv->tv_sec = sec;

	tv->tv_usec = usec;

}



EXPORT_SYMBOL(do_gettimeofday);



int do_settimeofday(struct timespec *tv)

{

	time_t wtm_sec, sec = tv->tv_sec;

	long wtm_nsec, nsec = tv->tv_nsec;



	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)

		return -EINVAL;



	write_seqlock_irq(&xtime_lock);

	/* This is revolting. We need to set the xtime.tv_nsec

	 * correctly. However, the value in this location is

	 * is value at the last tick.

	 * Discover what correction gettimeofday

	 * would have done, and then undo it!

	 */

	nsec -= do_gettimeoffset() * 1000;



	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);

	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);



	set_normalized_timespec(&xtime, sec, nsec);

	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);



	ntp_clear();

	write_sequnlock_irq(&xtime_lock);

	clock_was_set();

	return 0;

}



EXPORT_SYMBOL(do_settimeofday);





#ifdef CONFIG_PROFILING

#define s390_do_profile()	profile_tick(CPU_PROFILING)

#else
@@ -340,6 +273,22 @@ void init_cpu_timer(void) 


extern void vtime_init(void);



static cycle_t read_tod_clock(void)

{

	return get_clock();

}



static struct clocksource clocksource_tod = {

	.name		= "tod",

	.rating		= 100,

	.read		= read_tod_clock,

	.mask		= -1ULL,

	.mult		= 1000,

	.shift		= 12,

	.is_continuous	= 1,

};





/*

 * Initialize the TOD clock and the CPU timer of

 * the boot cpu.
@@ -384,6 +333,9 @@ void __init time_init(void) 
					      &ext_int_info_cc) != 0)

                panic("Couldn't request external interrupt 0x1004");



	if (clocksource_register(&clocksource_tod) != 0)

		panic("Could not register TOD clock source");



        init_cpu_timer();



#ifdef CONFIG_NO_IDLE_HZ