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greybus: timesync: Do 64 bit divisions in a 32 friendly way

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We need to use 'do_div()' when doing 64 bit division or modulo division
since the kernel will not pull in the gcc builtins __aeabi_ldivmod and
__aeabi_uldivmod on 32 bit builds.

Reported-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Bryan O'Donoghue 2016-06-10 16:10:12 +01:00 committed by Greg Kroah-Hartman
parent 6db9cc68d7
commit 4c2f8a48e9
1 changed files with 15 additions and 7 deletions
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22
drivers/staging/greybus/timesync.c
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@ -502,8 +502,7 @@ static int gb_timesync_to_timespec(struct gb_timesync_svc *timesync_svc,
u64 frame_time, struct timespec *ts)
{
unsigned long flags;
u64 delta_fs, counts;
u32 sec, nsec;
u64 delta_fs, counts, sec, nsec;
bool add;
int ret = 0;
@ -532,8 +531,15 @@ static int gb_timesync_to_timespec(struct gb_timesync_svc *timesync_svc,
/* Determine the time difference in femtoseconds */
delta_fs = counts * gb_timesync_fs_per_clock;
sec = delta_fs / FSEC_PER_SEC;
nsec = (delta_fs % FSEC_PER_SEC) / 1000000UL;
/* Convert to seconds */
sec = delta_fs;
do_div(sec, NSEC_PER_SEC);
do_div(sec, 1000000UL);
/* Get the nanosecond remainder */
nsec = do_div(delta_fs, sec);
do_div(nsec, 1000000UL);
if (add) {
/* Add the calculated offset - overflow nanoseconds upwards */
@ -548,7 +554,7 @@ static int gb_timesync_to_timespec(struct gb_timesync_svc *timesync_svc,
if (nsec > timesync_svc->ktime_data.ts.tv_nsec) {
sec++;
nsec = nsec + timesync_svc->ktime_data.ts.tv_nsec;
nsec %= NSEC_PER_SEC;
nsec = do_div(nsec, NSEC_PER_SEC);
} else {
nsec = timesync_svc->ktime_data.ts.tv_nsec - nsec;
}
@ -1318,8 +1324,10 @@ int __init gb_timesync_init(void)
gb_timesync_clock_rate = gb_timesync_platform_get_clock_rate();
/* Calculate nanoseconds and femtoseconds per clock */
gb_timesync_fs_per_clock = FSEC_PER_SEC / gb_timesync_clock_rate;
gb_timesync_ns_per_clock = NSEC_PER_SEC / gb_timesync_clock_rate;
gb_timesync_fs_per_clock = FSEC_PER_SEC;
do_div(gb_timesync_fs_per_clock, gb_timesync_clock_rate);
gb_timesync_ns_per_clock = NSEC_PER_SEC;
do_div(gb_timesync_ns_per_clock, gb_timesync_clock_rate);
/* Calculate the maximum number of clocks we will convert to ktime */
gb_timesync_max_ktime_diff =