[net 2/7] net/mlx5: IPSec, Fix 64-bit division on 32-bit builds

[Saeed Mahameed]

From: Ilan Tayari <il...@mellanox.com>

Fix warnings when building 386 kernel:
>> ERROR: "__udivdi3" [drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.ko] 
>> undefined!

Fixes: 2ac9cfe78223 ("net/mlx5e: IPSec, Add Innova IPSec offload TX data path")
Reported-by: kbuild test robot <fengguang...@intel.com>
Signed-off-by: Ilan Tayari <il...@mellanox.com>
Signed-off-by: Saeed Mahameed <sae...@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c 
b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
index 4a78aefdf157..7d06c673851a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c
@@ -363,6 +363,7 @@ void mlx5e_ipsec_build_inverse_table(void)
 {
        u16 mss_inv;
        u32 mss;
+       u64 n;
 
        /* Calculate 1/x inverse table for use in GSO data path.
         * Using this table, we provide the IPSec accelerator with the value of
@@ -372,7 +373,8 @@ void mlx5e_ipsec_build_inverse_table(void)
         */
        mlx5e_ipsec_inverse_table[1] = htons(0xFFFF);
        for (mss = 2; mss < MAX_LSO_MSS; mss++) {
-               mss_inv = ((1ULL << 32) / mss) >> 16;
+               n = 1ULL << 32;
+               mss_inv = do_div(n, mss) >> 16;
                mlx5e_ipsec_inverse_table[mss] = htons(mss_inv);
        }
 }
-- 
2.11.0