diff options
Diffstat (limited to 'arch/powerpc/kernel/time.c')
| -rw-r--r-- | arch/powerpc/kernel/time.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 48571ac56fb7..bee1443da763 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -109,7 +109,7 @@ static void decrementer_set_mode(enum clock_event_mode mode, static struct clock_event_device decrementer_clockevent = { .name = "decrementer", .rating = 200, - .shift = 16, + .shift = 0, /* To be filled in */ .mult = 0, /* To be filled in */ .irq = 0, .set_next_event = decrementer_set_next_event, @@ -843,6 +843,22 @@ static void decrementer_set_mode(enum clock_event_mode mode, decrementer_set_next_event(DECREMENTER_MAX, dev); } +static void __init setup_clockevent_multiplier(unsigned long hz) +{ + u64 mult, shift = 32; + + while (1) { + mult = div_sc(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; @@ -860,8 +876,7 @@ static void __init init_decrementer_clockevent(void) { int cpu = smp_processor_id(); - decrementer_clockevent.mult = div_sc(ppc_tb_freq, NSEC_PER_SEC, - decrementer_clockevent.shift); + setup_clockevent_multiplier(ppc_tb_freq); decrementer_clockevent.max_delta_ns = clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent); decrementer_clockevent.min_delta_ns = |
