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powerpc: Simplify update_vsyscall 

Currently powerpc's update_vsyscall calls an inline update_gtod.
However, both are straightforward, and there are no other users,
so this patch merges update_gtod into update_vsyscall.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1279068988-21864-5-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
John Stultz 2010-07-13 17:56:21 -07:00 committed by Thomas Gleixner
parent 592913ecb8
commit b0797b60d0
1 changed files with 25 additions and 30 deletions
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55
arch/powerpc/kernel/time.c
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@ -423,30 +423,6 @@ void udelay(unsigned long usecs)
} }
EXPORT_SYMBOL(udelay); EXPORT_SYMBOL(udelay);
static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
u64 new_tb_to_xs)
{
/*
* tb_update_count is used to allow the userspace gettimeofday code
* to assure itself that it sees a consistent view of the tb_to_xs and
* stamp_xsec variables. It reads the tb_update_count, then reads
* tb_to_xs and stamp_xsec and then reads tb_update_count again. If
* the two values of tb_update_count match and are even then the
* tb_to_xs and stamp_xsec values are consistent. If not, then it
* loops back and reads them again until this criteria is met.
* We expect the caller to have done the first increment of
* vdso_data->tb_update_count already.
*/
vdso_data->tb_orig_stamp = new_tb_stamp;
vdso_data->stamp_xsec = new_stamp_xsec;
vdso_data->tb_to_xs = new_tb_to_xs;
vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec;
vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec;
vdso_data->stamp_xtime = xtime;
smp_wmb();
++(vdso_data->tb_update_count);
}
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
unsigned long profile_pc(struct pt_regs *regs) unsigned long profile_pc(struct pt_regs *regs)
{ {
@ -876,7 +852,7 @@ static cycle_t timebase_read(struct clocksource *cs)
void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, void update_vsyscall(struct timespec *wall_time, struct clocksource *clock,
u32 mult) u32 mult)
{ {
u64 t2x, stamp_xsec; u64 new_tb_to_xs, new_stamp_xsec;
if (clock != &clocksource_timebase) if (clock != &clocksource_timebase)
return; return;
@ -887,11 +863,30 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock,
/* XXX this assumes clock->shift == 22 */ /* XXX this assumes clock->shift == 22 */
/* 4611686018 ~= 2^(20+64-22) / 1e9 */ /* 4611686018 ~= 2^(20+64-22) / 1e9 */
t2x = (u64) mult * 4611686018ULL; new_tb_to_xs = (u64) mult * 4611686018ULL;
stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC;
do_div(stamp_xsec, 1000000000); do_div(new_stamp_xsec, 1000000000);
stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC;
update_gtod(clock->cycle_last, stamp_xsec, t2x);
/*
* tb_update_count is used to allow the userspace gettimeofday code
* to assure itself that it sees a consistent view of the tb_to_xs and
* stamp_xsec variables. It reads the tb_update_count, then reads
* tb_to_xs and stamp_xsec and then reads tb_update_count again. If
* the two values of tb_update_count match and are even then the
* tb_to_xs and stamp_xsec values are consistent. If not, then it
* loops back and reads them again until this criteria is met.
* We expect the caller to have done the first increment of
* vdso_data->tb_update_count already.
*/
vdso_data->tb_orig_stamp = clock->cycle_last;
vdso_data->stamp_xsec = new_stamp_xsec;
vdso_data->tb_to_xs = new_tb_to_xs;
vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec;
vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec;
vdso_data->stamp_xtime = xtime;
smp_wmb();
++(vdso_data->tb_update_count);
} }
void update_vsyscall_tz(void) void update_vsyscall_tz(void)