powerpc/time: Use clockevents_calc_mult_shift
We can use clockevents_calc_mult_shift instead of doing all
the work ourselves.
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 5db163c..fae3094 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -112,8 +112,6 @@
static struct clock_event_device decrementer_clockevent = {
.name = "decrementer",
.rating = 200,
- .shift = 0, /* To be filled in */
- .mult = 0, /* To be filled in */
.irq = 0,
.set_next_event = decrementer_set_next_event,
.set_mode = decrementer_set_mode,
@@ -913,31 +911,6 @@
decrementer_set_next_event(DECREMENTER_MAX, dev);
}
-static inline uint64_t div_sc64(unsigned long ticks, unsigned long nsec,
- int shift)
-{
- uint64_t tmp = ((uint64_t)ticks) << shift;
-
- do_div(tmp, nsec);
- return tmp;
-}
-
-static void __init setup_clockevent_multiplier(unsigned long hz)
-{
- u64 mult, shift = 32;
-
- while (1) {
- mult = div_sc64(hz, NSEC_PER_SEC, shift);
- if (mult && (mult >> 32UL) == 0UL)
- break;
-
- shift--;
- }
-
- decrementer_clockevent.shift = shift;
- decrementer_clockevent.mult = mult;
-}
-
static void register_decrementer_clockevent(int cpu)
{
struct clock_event_device *dec = &per_cpu(decrementers, cpu).event;
@@ -955,7 +928,8 @@
{
int cpu = smp_processor_id();
- setup_clockevent_multiplier(ppc_tb_freq);
+ clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4);
+
decrementer_clockevent.max_delta_ns =
clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
decrementer_clockevent.min_delta_ns =