Commit d8afc6fd authored by Anton Blanchard's avatar Anton Blanchard Committed by Benjamin Herrenschmidt
Browse files

powerpc/time: Use clockevents_calc_mult_shift 



We can use clockevents_calc_mult_shift instead of doing all
the work ourselves.

Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 37fb9a02

arch/powerpc/kernel/time.c

+2 −28
Original line number Diff line number Diff line
@@ -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 =