cxgb4: add loopback ethtool self-test

In this test, loopback pkt is created and sent on default queue.
The packet goes until the Multi Port Switch (MPS) just before
the MAC and based on the specified channel number, it either
goes outside the wire on one of the physical ports or looped
back to Rx path by MPS. In this case, we're specifying loopback
channel, instead of physical ports, so the packet gets looped
back to Rx path, instead of getting transmitted on the wire.

v3:
- Modify commit message to include test details.
v2:
- Add only loopback self-test.

Signed-off-by: Vishal Kulkarni <vishal@chelsio.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c
index b66a2e6cbbeb..12ef9ddd1e54 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c
@@ -25,6 +25,15 @@ static void set_msglevel(struct net_device *dev, u32 val)
 	netdev2adap(dev)->msg_enable = val;
 }
 
+enum cxgb4_ethtool_tests {
+	CXGB4_ETHTOOL_LB_TEST,
+	CXGB4_ETHTOOL_MAX_TEST,
+};
+
+static const char cxgb4_selftest_strings[CXGB4_ETHTOOL_MAX_TEST][ETH_GSTRING_LEN] = {
+	"Loop back test",
+};
+
 static const char * const flash_region_strings[] = {
 	"All",
 	"Firmware",
@@ -166,6 +175,8 @@ static int get_sset_count(struct net_device *dev, int sset)
 		       ARRAY_SIZE(loopback_stats_strings);
 	case ETH_SS_PRIV_FLAGS:
 		return ARRAY_SIZE(cxgb4_priv_flags_strings);
+	case ETH_SS_TEST:
+		return ARRAY_SIZE(cxgb4_selftest_strings);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -228,6 +239,9 @@ static void get_strings(struct net_device *dev, u32 stringset, u8 *data)
 	} else if (stringset == ETH_SS_PRIV_FLAGS) {
 		memcpy(data, cxgb4_priv_flags_strings,
 		       sizeof(cxgb4_priv_flags_strings));
+	} else if (stringset == ETH_SS_TEST) {
+		memcpy(data, cxgb4_selftest_strings,
+		       sizeof(cxgb4_selftest_strings));
 	}
 }
 
@@ -2056,6 +2070,43 @@ static int cxgb4_set_priv_flags(struct net_device *netdev, u32 flags)
 	return 0;
 }
 
+static void cxgb4_lb_test(struct net_device *netdev, u64 *lb_status)
+{
+	int dev_state = netif_running(netdev);
+
+	if (dev_state) {
+		netif_tx_stop_all_queues(netdev);
+		netif_carrier_off(netdev);
+	}
+
+	*lb_status = cxgb4_selftest_lb_pkt(netdev);
+
+	if (dev_state) {
+		netif_tx_start_all_queues(netdev);
+		netif_carrier_on(netdev);
+	}
+}
+
+static void cxgb4_self_test(struct net_device *netdev,
+			    struct ethtool_test *eth_test, u64 *data)
+{
+	struct port_info *pi = netdev_priv(netdev);
+	struct adapter *adap = pi->adapter;
+
+	memset(data, 0, sizeof(u64) * CXGB4_ETHTOOL_MAX_TEST);
+
+	if (!(adap->flags & CXGB4_FW_OK)) {
+		eth_test->flags |= ETH_TEST_FL_FAILED;
+		return;
+	}
+
+	if (eth_test->flags == ETH_TEST_FL_OFFLINE)
+		cxgb4_lb_test(netdev, &data[CXGB4_ETHTOOL_LB_TEST]);
+
+	if (data[CXGB4_ETHTOOL_LB_TEST])
+		eth_test->flags |= ETH_TEST_FL_FAILED;
+}
+
 static const struct ethtool_ops cxgb_ethtool_ops = {
 	.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
 				     ETHTOOL_COALESCE_RX_MAX_FRAMES |
@@ -2090,6 +2141,7 @@ static const struct ethtool_ops cxgb_ethtool_ops = {
 	.get_rxfh_indir_size = get_rss_table_size,
 	.get_rxfh	   = get_rss_table,
 	.set_rxfh	   = set_rss_table,
+	.self_test	   = cxgb4_self_test,
 	.flash_device      = set_flash,
 	.get_ts_info       = get_ts_info,
 	.set_dump          = set_dump,