[PATCH] mlxsw: spectrum_ptp: fix 32-bit build

[Arnd Bergmann]

On 32-bit architectures, we cannot easily device 64-bit numbers:

ERROR: "__aeabi_uldivmod" 
[drivers/net/ethernet/mellanox/mlxsw/mlxsw_spectrum.ko] undefined!

Use do_div() to annotate the fact that we know this is an
expensive operation.

Fixes: 992aa864dca0 ("mlxsw: spectrum_ptp: Add implementation for physical 
hardware clock operations")
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c 
b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
index 2a9bbc90225e..618e329e1490 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
@@ -87,7 +87,7 @@ mlxsw_sp1_ptp_phc_settime(struct mlxsw_sp_ptp_clock *clock, 
u64 nsec)
        u32 next_sec;
        int err;
 
-       next_sec = nsec / NSEC_PER_SEC + 1;
+       next_sec = div_u64(nsec, NSEC_PER_SEC) + 1;
        next_sec_in_nsec = next_sec * NSEC_PER_SEC;
 
        spin_lock(&clock->lock);
-- 
2.20.0