[PATCH -next] net: mvpp2: Use div64_ul instead of do_div

From: Yang Li
Date: Wed Nov 17 2021 - 22:05:27 EST


do_div() does a 64-by-32 division. Here the divisor is an
unsigned long which on some platforms is 64 bit wide. So use
div64_ul instead of do_div to avoid a possible truncation.

Eliminate the following coccicheck warning:
./drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:2742:1-7: WARNING:
do_div() does a 64-by-32 division, please consider using div64_ul
instead.

Reported-by: Abaci Robot <abaci@xxxxxxxxxxxxxxxxx>
Signed-off-by: Yang Li <yang.lee@xxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index df6c793..41244a5 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -2739,7 +2739,7 @@ static u32 mvpp2_cycles_to_usec(u32 cycles, unsigned long clk_hz)
{
u64 tmp = (u64)cycles * USEC_PER_SEC;

- do_div(tmp, clk_hz);
+ tmp = div64_ul(tmp, clk_hz);

return tmp > U32_MAX ? U32_MAX : tmp;
}
--
1.8.3.1