From: Nathan Chancellor <natechancellor@gmail.com>
Date: Wed, 30 Oct 2019 09:01:52 -0700
Subject: mlxsw: Fix 64-bit division in mlxsw_sp_sb_prs_init
Patch-mainline: v5.5-rc1
Git-commit: d170eb69d40e9e5fccb8d57edbbacb97427dcf1c
References: bsc#1154488

When building for 32-bit ARM, there is a link time error because of a
64-bit division:

ld.lld: error: undefined symbol: __aeabi_uldivmod
>>> referenced by spectrum_buffers.c
>>>               net/ethernet/mellanox/mlxsw/spectrum_buffers.o:(mlxsw_sp_buffers_init) in archive drivers/built-in.a
>>> did you mean: __aeabi_uidivmod
>>> defined in: arch/arm/lib/lib.a(lib1funcs.o

Avoid this by using div_u64, which is designed to avoid this problem.

Fixes: bc9f6e94bcb5 ("mlxsw: spectrum_buffers: Calculate the size of the main pool")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c
@@ -470,7 +470,7 @@ static int mlxsw_sp_sb_prs_init(struct m
 				size_t prs_len)
 {
 	/* Round down, unlike mlxsw_sp_bytes_cells(). */
-	u32 sb_cells = mlxsw_sp->sb->sb_size / mlxsw_sp->sb->cell_size;
+	u32 sb_cells = div_u64(mlxsw_sp->sb->sb_size, mlxsw_sp->sb->cell_size);
 	u32 rest_cells[2] = {sb_cells, sb_cells};
 	int i;
 	int err;