mlxsw: spectrum: Do not rely on machine endianness

The second commit cited below performed a cast of 'u32 buffsize' to
'(u16 *)' when calling mlxsw_sp_port_headroom_8x_adjust():

mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, (u16 *) &buffsize);

Colin noted that this will behave differently on big endian
architectures compared to little endian architectures.

Fix this by following Colin's suggestion and have the function accept
and return 'u32' instead of passing the current size by reference.

Fixes: da382875c616 ("mlxsw: spectrum: Extend to support Spectrum-3 ASIC")
Fixes: 60833d54d56c ("mlxsw: spectrum: Adjust headroom buffers for 8x ports")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Suggested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 55af877763ed4c1f9b868fb20f8563e7db9c2d33..029ea344ad656bcba62822d5efd462e1426ed4d2 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -978,10 +978,10 @@ int __mlxsw_sp_port_headroom_set(struct mlxsw_sp_port *mlxsw_sp_port, int mtu,
 
                lossy = !(pfc || pause_en);
                thres_cells = mlxsw_sp_pg_buf_threshold_get(mlxsw_sp, mtu);
-               mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, &thres_cells);
+               thres_cells = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, thres_cells);
                delay_cells = mlxsw_sp_pg_buf_delay_get(mlxsw_sp, mtu, delay,
                                                        pfc, pause_en);
-               mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, &delay_cells);
+               delay_cells = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, delay_cells);
                total_cells = thres_cells + delay_cells;
 
                taken_headroom_cells += total_cells;

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
index 6e87457dd635bef9a0ee38a88f4801ff3c3f3ac6..3abe3e7d89bc83877ccfe2cd151f194d04e4d3e0 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
@@ -374,17 +374,15 @@ mlxsw_sp_port_vlan_find_by_vid(const struct mlxsw_sp_port *mlxsw_sp_port,
        return NULL;
 }
 
-static inline void
+static inline u32
 mlxsw_sp_port_headroom_8x_adjust(const struct mlxsw_sp_port *mlxsw_sp_port,
-                                u16 *p_size)
+                                u32 size_cells)
 {
        /* Ports with eight lanes use two headroom buffers between which the
         * configured headroom size is split. Therefore, multiply the calculated
         * headroom size by two.
         */
-       if (mlxsw_sp_port->mapping.width != 8)
-               return;
-       *p_size *= 2;
+       return mlxsw_sp_port->mapping.width == 8 ? 2 * size_cells : size_cells;
 }
 
 enum mlxsw_sp_flood_type {

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c
index f25a8b084b4bb3e1b0c871b3349b5fbf0f99ad09..6f84557a5a6f05f9fb401155635f18768e111fa5 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_buffers.c
@@ -312,7 +312,7 @@ static int mlxsw_sp_port_pb_init(struct mlxsw_sp_port *mlxsw_sp_port)
 
                if (i == MLXSW_SP_PB_UNUSED)
                        continue;
-               mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, &size);
+               size = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, size);
                mlxsw_reg_pbmc_lossy_buffer_pack(pbmc_pl, i, size);
        }
        mlxsw_reg_pbmc_lossy_buffer_pack(pbmc_pl,

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
index f843545d3478d6c9cc49041e2cf13feb1ec55a31..92351a79addc32383a2de21cdfe7d3436ac96922 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
@@ -782,7 +782,7 @@ mlxsw_sp_span_port_buffer_update(struct mlxsw_sp_port *mlxsw_sp_port, u16 mtu)
                speed = 0;
 
        buffsize = mlxsw_sp_span_buffsize_get(mlxsw_sp, speed, mtu);
-       mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, (u16 *) &buffsize);
+       buffsize = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, buffsize);
        mlxsw_reg_sbib_pack(sbib_pl, mlxsw_sp_port->local_port, buffsize);
        return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
 }