summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/time.c')
-rw-r--r--arch/powerpc/kernel/time.c21
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 =
OpenPOWER on IntegriCloud