openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

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: John Stultz <johnstul@us.ibm.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
john stultz 2009-09-21 17:04:04 -07:00 committed by Linus Torvalds
parent d5a6d17395
commit 95ad759c6b
2 changed files with 9 additions and 71 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/m32r/Kconfig
View File

@ -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"

74
arch/m32r/kernel/time.c
View File

@ -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