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>

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 0441bbd..6fcd648 100644 (file)
--- 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)