3.18-stable review patch. If anyone has any objections, please let me know.
------------------ From: Amir Vadai <[email protected]> [ Upstream commit 492f5add4be84652bbe13da8a250d60c6856a5c5 ] iowrite32() will byteswap it's argument on big endian archs. iowrite32be() will byteswap on little endian archs. Since we don't want to do this unnecessary byteswap on the fast path, doorbell is stored in the NIC's native endianness. Using the right iowrite() according to the arch endianness. CC: Wei Yang <[email protected]> CC: David Laight <[email protected]> Fixes: 6a4e812 ("net/mlx4_en: Avoid calling bswap in tx fast path") Signed-off-by: Amir Vadai <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -954,7 +954,17 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff tx_desc->ctrl.owner_opcode = op_own; if (send_doorbell) { wmb(); - iowrite32(ring->doorbell_qpn, + /* Since there is no iowrite*_native() that writes the + * value as is, without byteswapping - using the one + * the doesn't do byteswapping in the relevant arch + * endianness. + */ +#if defined(__LITTLE_ENDIAN) + iowrite32( +#else + iowrite32be( +#endif + ring->doorbell_qpn, ring->bf.uar->map + MLX4_SEND_DOORBELL); } else { ring->xmit_more++; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
