powerpc/time: Use clocksource_register_hz
Use clocksource_register_hz which calculates the shift/mult
factors for us. Also remove the shift = 22 assumption in
vsyscall_update - thanks to Paul Mackerras and John Stultz for
catching that.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index fae3094..d204b72 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -86,8 +86,6 @@
.rating = 400,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.mask = CLOCKSOURCE_MASK(64),
- .shift = 22,
- .mult = 0, /* To be filled in */
.read = rtc_read,
};
@@ -97,8 +95,6 @@
.rating = 400,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.mask = CLOCKSOURCE_MASK(64),
- .shift = 22,
- .mult = 0, /* To be filled in */
.read = timebase_read,
};
@@ -822,9 +818,8 @@
++vdso_data->tb_update_count;
smp_mb();
- /* XXX this assumes clock->shift == 22 */
- /* 4611686018 ~= 2^(20+64-22) / 1e9 */
- new_tb_to_xs = (u64) mult * 4611686018ULL;
+ /* 19342813113834067 ~= 2^(20+64) / 1e9 */
+ new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift);
new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC;
do_div(new_stamp_xsec, 1000000000);
new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC;
@@ -875,9 +870,7 @@
else
clock = &clocksource_timebase;
- clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift);
-
- if (clocksource_register(clock)) {
+ if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
printk(KERN_ERR "clocksource: %s is already registered\n",
clock->name);
return;