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Commit 95ad759c authored by John Stultz's avatar John Stultz Committed by Linus Torvalds
Browse files

m32r: convert to use arch_gettimeoffset() 



Convert m32r to use GENERIC_TIME via the arch_getoffset() infrastructure,
reducing the amount of arch specific code we need to maintain.

I also noted that m32r doesn't seem to be taking the xtime write lock
before calling do_timer()!  That looks like a pretty bad bug to me.  If
folks agree, let me know and I can move the lock grab to the correct spot.

Signed-off-by: default avatarJohn Stultz <johnstul@us.ibm.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d5a6d173

arch/m32r/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -41,6 +41,12 @@ config HZ 
	int

	default 100



config GENERIC_TIME

	def_bool y



config ARCH_USES_GETTIMEOFFSET

	def_bool y



source "init/Kconfig"



source "kernel/Kconfig.freezer"

arch/m32r/kernel/time.c

+3 −71
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ extern void smp_local_timer_interrupt(void); 


static unsigned long latch;



static unsigned long do_gettimeoffset(void)

u32 arch_gettimeoffset(void)

{

	unsigned long  elapsed_time = 0;  /* [us] */
@@ -93,78 +93,9 @@ static unsigned long do_gettimeoffset(void) 
#error no chip configuration

#endif



	return elapsed_time;

	return elapsed_time * 1000;

}



/*

 * This version of gettimeofday has near microsecond resolution.

 */

void do_gettimeofday(struct timeval *tv)

{

	unsigned long seq;

	unsigned long usec, sec;

	unsigned long max_ntp_tick = tick_usec - tickadj;



	do {

		seq = read_seqbegin(&xtime_lock);



		usec = do_gettimeoffset();



		/*

		 * If time_adjust is negative then NTP is slowing the clock

		 * so make sure not to go into next possible interval.

		 * Better to lose some accuracy than have time go backwards..

		 */

		if (unlikely(time_adjust < 0))

			usec = min(usec, max_ntp_tick);



		sec = xtime.tv_sec;

		usec += (xtime.tv_nsec / 1000);

	} while (read_seqretry(&xtime_lock, seq));



	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 "xtime" correctly. However, the

	 * value in this location is the value at the most recent update of

	 * wall time.  Discover what correction gettimeofday() would have

	 * made, and then undo it!

	 */

	nsec -= do_gettimeoffset() * NSEC_PER_USEC;



	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);



/*

 * In order to set the CMOS clock precisely, set_rtc_mmss has to be

 * called 500 ms after the second nowtime has started, because when
@@ -192,6 +123,7 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id) 
#ifndef CONFIG_SMP

	profile_tick(CPU_PROFILING);

#endif

	/* XXX FIXME. Uh, the xtime_lock should be held here, no? */

	do_timer(1);



#ifndef CONFIG_SMP