diff options
Diffstat (limited to 'arch/tile/kernel/time.c')
| -rw-r--r-- | arch/tile/kernel/time.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/tile/kernel/time.c b/arch/tile/kernel/time.c index 5d10642db63..462dcd0c170 100644 --- a/arch/tile/kernel/time.c +++ b/arch/tile/kernel/time.c @@ -236,7 +236,15 @@ cycles_t ns2cycles(unsigned long nsecs) * clock frequency. */ struct clock_event_device *dev = &__raw_get_cpu_var(tile_timer); - return ((u64)nsecs * dev->mult) >> dev->shift; + + /* + * as in clocksource.h and x86's timer.h, we split the calculation + * into 2 parts to avoid unecessary overflow of the intermediate + * value. This will not lead to any loss of precision. + */ + u64 quot = (u64)nsecs >> dev->shift; + u64 rem = (u64)nsecs & ((1ULL << dev->shift) - 1); + return quot * dev->mult + ((rem * dev->mult) >> dev->shift); } void update_vsyscall_tz(void) |