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powerpc/time: Use clockevents_calc_mult_shift

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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>
This commit is contained in:
Anton Blanchard 2011-11-23 20:07:18 +00:00 committed by Benjamin Herrenschmidt
parent 37fb9a0231
commit d8afc6fd95
1 changed files with 2 additions and 28 deletions
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30
arch/powerpc/kernel/time.c
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@ -112,8 +112,6 @@ static void decrementer_set_mode(enum clock_event_mode mode,
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 @@ static void decrementer_set_mode(enum clock_event_mode mode,
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 @@ static void __init init_decrementer_clockevent(void)
{
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 =