From b0797b60d0067fe437baa97a743c7d9de98fd769 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 13 Jul 2010 17:56:21 -0700 Subject: [PATCH] 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 Cc: Anton Blanchard Cc: Paul Mackerras LKML-Reference: <1279068988-21864-5-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner --- arch/powerpc/kernel/time.c | 55 +++++++++++++++++++++------------------------- 1 file changed, 25 insertions(+), 30 deletions(-) diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 0441bbd..6fcd648 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -423,30 +423,6 @@ void udelay(unsigned long usecs) } 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 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, u32 mult) { - u64 t2x, stamp_xsec; + u64 new_tb_to_xs, new_stamp_xsec; if (clock != &clocksource_timebase) return; @@ -887,11 +863,30 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, /* XXX this assumes clock->shift == 22 */ /* 4611686018 ~= 2^(20+64-22) / 1e9 */ - t2x = (u64) mult * 4611686018ULL; - stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; - do_div(stamp_xsec, 1000000000); - stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; - update_gtod(clock->cycle_last, stamp_xsec, t2x); + new_tb_to_xs = (u64) mult * 4611686018ULL; + new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC; + do_div(new_stamp_xsec, 1000000000); + new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC; + + /* + * 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) -- 2.7.4