sfc: Use separate hardware TX queues to select checksum generation

Checksum generation is an attribute of our hardware TX queues, not TX
descriptors.  We previously used a single queue and turned checksum
generation on or off as requested through ethtool.  However, this can
result in regenerating checksums in raw packets that should not be
modified.  We now create 2 hardware TX queues with checksum generation
on or off.  They are presented to the net core as one queue since it
does not know how to select between them.

The self-test verifies that a bad checksum is unaltered on the queue
with checksum generation off.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 2 insertions, 43 deletions

diff --git a/drivers/net/sfc/ethtool.c b/drivers/net/sfc/ethtool.c
index 8a15be6548d2..ccd82f12456c 100644
--- a/drivers/net/sfc/ethtool.c
+++ b/drivers/net/sfc/ethtool.c
@@ -32,8 +32,6 @@ const char *efx_loopback_mode_names[] = {
         [LOOPBACK_NETWORK]      = "NETWORK",
 };
 
-static int efx_ethtool_set_tx_csum(struct net_device *net_dev, u32 enable);
-
 struct ethtool_string {
         char name[ETH_GSTRING_LEN];
 };
@@ -442,45 +440,6 @@ static void efx_ethtool_get_stats(struct net_device *net_dev,
         }
 }
 
-static int efx_ethtool_set_tso(struct net_device *net_dev, u32 enable)
-{
-        int rc;
-
-        /* Our TSO requires TX checksumming, so force TX checksumming
-         * on when TSO is enabled.
-         */
-        if (enable) {
-                rc = efx_ethtool_set_tx_csum(net_dev, 1);
-                if (rc)
-                        return rc;
-        }
-
-        return ethtool_op_set_tso(net_dev, enable);
-}
-
-static int efx_ethtool_set_tx_csum(struct net_device *net_dev, u32 enable)
-{
-        struct efx_nic *efx = netdev_priv(net_dev);
-        int rc;
-
-        rc = ethtool_op_set_tx_csum(net_dev, enable);
-        if (rc)
-                return rc;
-
-        efx_flush_queues(efx);
-
-        /* Our TSO requires TX checksumming, so disable TSO when
-         * checksumming is disabled
-         */
-        if (!enable) {
-                rc = efx_ethtool_set_tso(net_dev, 0);
-                if (rc)
-                        return rc;
-        }
-
-        return 0;
-}
-
 static int efx_ethtool_set_rx_csum(struct net_device *net_dev, u32 enable)
 {
         struct efx_nic *efx = netdev_priv(net_dev);
@@ -701,11 +660,11 @@ struct ethtool_ops efx_ethtool_ops = {
         .get_rx_csum            = efx_ethtool_get_rx_csum,
         .set_rx_csum            = efx_ethtool_set_rx_csum,
         .get_tx_csum            = ethtool_op_get_tx_csum,
-        .set_tx_csum            = efx_ethtool_set_tx_csum,
+        .set_tx_csum            = ethtool_op_set_tx_csum,
         .get_sg                 = ethtool_op_get_sg,
         .set_sg                 = ethtool_op_set_sg,
         .get_tso                = ethtool_op_get_tso,
-        .set_tso                = efx_ethtool_set_tso,
+        .set_tso                = ethtool_op_set_tso,
         .get_flags              = ethtool_op_get_flags,
         .set_flags              = ethtool_op_set_flags,
         .self_test_count        = efx_ethtool_self_test_count,