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[S390] Use CONFIG_GENERIC_TIME and define TOD clock source.

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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: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2006-10-06 16:38:48 +02:00
parent 2033b0c330
commit dc64bef543
3 changed files with 24 additions and 68 deletions
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3
arch/s390/Kconfig
View File

@ -30,6 +30,9 @@ config GENERIC_CALIBRATE_DELAY
bool
default y
config GENERIC_TIME
def_bool y
config GENERIC_BUST_SPINLOCK
bool

1
arch/s390/defconfig
View File

@ -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"

88
arch/s390/kernel/time.c
View File

@ -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