[PATCH net-next 4/4] cxgb4: add loop back test to ethtool

[Vishal Kulkarni <vishal@chelsio.com>]

In this test, loopback pkt is created and sent on default queue.

Signed-off-by: Vishal Kulkarni <vishal@chelsio.com>
---
 drivers/net/ethernet/chelsio/cxgb4/cxgb4.h    |   8 ++
 .../ethernet/chelsio/cxgb4/cxgb4_ethtool.c    |  22 ++++
 drivers/net/ethernet/chelsio/cxgb4/sge.c      | 107 +++++++++++++++++-
 3 files changed, 136 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
index c59e9ccc2f18..adbc0d088070 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
@@ -532,6 +532,12 @@ static inline struct mbox_cmd *mbox_cmd_log_entry(struct mbox_cmd_log *log,
 		FW_HDR_FW_VER_BUILD_G(chip##FW_VERSION_BUILD))
 #define FW_INTFVER(chip, intf) (FW_HDR_INTFVER_##intf)
 
+struct cxgb4_ethtool_lb_test {
+	struct completion completion;
+	int result;
+	int loopback;
+};
+
 struct fw_info {
 	u8 chip;
 	char *fs_name;
@@ -685,6 +691,7 @@ struct port_info {
 	u16 nmirrorqsets;
 	u32 vi_mirror_count;
 	struct mutex vi_mirror_mutex; /* Sync access to Mirror VI info */
+	struct cxgb4_ethtool_lb_test ethtool_lb;
 };
 
 struct dentry;
@@ -1595,6 +1602,7 @@ void t4_free_sge_resources(struct adapter *adap);
 void t4_free_ofld_rxqs(struct adapter *adap, int n, struct sge_ofld_rxq *q);
 irq_handler_t t4_intr_handler(struct adapter *adap);
 netdev_tx_t t4_start_xmit(struct sk_buff *skb, struct net_device *dev);
+int cxgb4_selftest_lb_pkt(struct net_device *netdev);
 int t4_ethrx_handler(struct sge_rspq *q, const __be64 *rsp,
 		     const struct pkt_gl *gl);
 int t4_mgmt_tx(struct adapter *adap, struct sk_buff *skb);
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c
index 5d3eb44dee46..9773a4ab435b 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c
@@ -29,6 +29,7 @@ enum cxgb4_ethtool_tests {
 	CXGB4_ETHTOOL_ADAPTER_TEST,
 	CXGB4_ETHTOOL_LINK_TEST,
 	CXGB4_ETHTOOL_LINK_SPEED_TEST,
+	CXGB4_ETHTOOL_LB_TEST,
 	CXGB4_ETHTOOL_MAX_TEST,
 };
 
@@ -36,6 +37,7 @@ static const char cxgb4_selftest_strings[CXGB4_ETHTOOL_MAX_TEST][ETH_GSTRING_LEN
 	"Adapter health status",
 	"Link test",
 	"Link speed test",
+	"Loop back test",
 };
 
 static const char * const flash_region_strings[] = {
@@ -2124,6 +2126,23 @@ static void cxgb4_link_speed_test(struct net_device *netdev, u64 *data)
 	*data = 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)
 {
@@ -2144,6 +2163,9 @@ static void cxgb4_self_test(struct net_device *netdev,
 	cxgb4_link_test(netdev, &data[CXGB4_ETHTOOL_LINK_TEST]);
 	cxgb4_link_speed_test(netdev, &data[CXGB4_ETHTOOL_LINK_SPEED_TEST]);
 
+	if (eth_test->flags == ETH_TEST_FL_OFFLINE)
+		cxgb4_lb_test(netdev, &data[CXGB4_ETHTOOL_LB_TEST]);
+
 	for (i = CXGB4_ETHTOOL_ADAPTER_TEST; i < CXGB4_ETHTOOL_MAX_TEST; i++) {
 		if (data[i]) {
 			eth_test->flags |= ETH_TEST_FL_FAILED;
diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index f9c6f13d7c99..3f0fdffdb2b5 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -2537,6 +2537,80 @@ static void ctrlq_check_stop(struct sge_ctrl_txq *q, struct fw_wr_hdr *wr)
 	}
 }
 
+#define CXGB4_SELFTEST_LB_STR "CHELSIO_SELFTEST"
+
+int cxgb4_selftest_lb_pkt(struct net_device *netdev)
+{
+	struct port_info *pi = netdev_priv(netdev);
+	struct adapter *adap = pi->adapter;
+	struct cxgb4_ethtool_lb_test *lb;
+	int ret, i = 0, pkt_len, credits;
+	struct fw_eth_tx_pkt_wr *wr;
+	struct cpl_tx_pkt_core *cpl;
+	u32 ctrl0, ndesc, flits;
+	struct sge_eth_txq *q;
+	u8 *sgl;
+
+	pkt_len = ETH_HLEN + sizeof(CXGB4_SELFTEST_LB_STR);
+
+	flits = DIV_ROUND_UP(pkt_len + sizeof(struct cpl_tx_pkt) +
+			     sizeof(*wr), sizeof(__be64));
+	ndesc = flits_to_desc(flits);
+
+	lb = &pi->ethtool_lb;
+	lb->loopback = 1;
+
+	q = &adap->sge.ethtxq[pi->first_qset];
+
+	reclaim_completed_tx(adap, &q->q, -1, true);
+	credits = txq_avail(&q->q) - ndesc;
+	if (unlikely(credits < 0))
+		return -ENOMEM;
+
+	wr = (void *)&q->q.desc[q->q.pidx];
+	memset(wr, 0, sizeof(struct tx_desc));
+
+	wr->op_immdlen = htonl(FW_WR_OP_V(FW_ETH_TX_PKT_WR) |
+			       FW_WR_IMMDLEN_V(pkt_len +
+			       sizeof(*cpl)));
+	wr->equiq_to_len16 = htonl(FW_WR_LEN16_V(DIV_ROUND_UP(flits, 2)));
+	wr->r3 = cpu_to_be64(0);
+
+	cpl = (void *)(wr + 1);
+	sgl = (u8 *)(cpl + 1);
+
+	ctrl0 = TXPKT_OPCODE_V(CPL_TX_PKT_XT) | TXPKT_PF_V(adap->pf) |
+		TXPKT_INTF_V(pi->tx_chan + 4);
+
+	cpl->ctrl0 = htonl(ctrl0);
+	cpl->pack = htons(0);
+	cpl->len = htons(pkt_len);
+	cpl->ctrl1 = cpu_to_be64(TXPKT_L4CSUM_DIS_F | TXPKT_IPCSUM_DIS_F);
+
+	eth_broadcast_addr(sgl);
+	i += ETH_ALEN;
+	ether_addr_copy(&sgl[i], netdev->dev_addr);
+	i += ETH_ALEN;
+
+	snprintf(&sgl[i], sizeof(CXGB4_SELFTEST_LB_STR), "%s",
+		 CXGB4_SELFTEST_LB_STR);
+
+	init_completion(&lb->completion);
+	txq_advance(&q->q, ndesc);
+	cxgb4_ring_tx_db(adap, &q->q, ndesc);
+
+	/* wait for the pkt to return */
+	ret = wait_for_completion_timeout(&lb->completion, 10 * HZ);
+	if (!ret)
+		ret = -ETIMEDOUT;
+	else
+		ret = lb->result;
+
+	lb->loopback = 0;
+
+	return ret;
+}
+
 /**
  *	ctrl_xmit - send a packet through an SGE control Tx queue
  *	@q: the control queue
@@ -3413,6 +3487,31 @@ static void t4_tx_completion_handler(struct sge_rspq *rspq,
 	t4_sge_eth_txq_egress_update(adapter, txq, -1);
 }
 
+static int cxgb4_validate_lb_pkt(struct port_info *pi, const struct pkt_gl *si)
+{
+	struct adapter *adap = pi->adapter;
+	struct cxgb4_ethtool_lb_test *lb;
+	struct sge *s = &adap->sge;
+	struct net_device *netdev;
+	u8 *data;
+	int i;
+
+	netdev = adap->port[pi->port_id];
+	lb = &pi->ethtool_lb;
+	data = si->va + s->pktshift;
+
+	i = ETH_ALEN;
+	if (!ether_addr_equal(data + i, netdev->dev_addr))
+		return -1;
+
+	i += ETH_ALEN;
+	if (strcmp(&data[i], CXGB4_SELFTEST_LB_STR))
+		lb->result = -EIO;
+
+	complete(&lb->completion);
+	return 0;
+}
+
 /**
  *	t4_ethrx_handler - process an ingress ethernet packet
  *	@q: the response queue that received the packet
@@ -3436,6 +3535,7 @@ int t4_ethrx_handler(struct sge_rspq *q, const __be64 *rsp,
 	struct port_info *pi;
 	int ret = 0;
 
+	pi = netdev_priv(q->netdev);
 	/* If we're looking at TX Queue CIDX Update, handle that separately
 	 * and return.
 	 */
@@ -3463,6 +3563,12 @@ int t4_ethrx_handler(struct sge_rspq *q, const __be64 *rsp,
 	if (err_vec)
 		rxq->stats.bad_rx_pkts++;
 
+	if (unlikely(pi->ethtool_lb.loopback && pkt->iff >= NCHAN)) {
+		ret = cxgb4_validate_lb_pkt(pi, si);
+		if (!ret)
+			return 0;
+	}
+
 	if (((pkt->l2info & htonl(RXF_TCP_F)) ||
 	     tnl_hdr_len) &&
 	    (q->netdev->features & NETIF_F_GRO) && csum_ok && !pkt->ip_frag) {
@@ -3476,7 +3582,6 @@ int t4_ethrx_handler(struct sge_rspq *q, const __be64 *rsp,
 		rxq->stats.rx_drops++;
 		return 0;
 	}
-	pi = netdev_priv(q->netdev);
 
 	/* Handle PTP Event Rx packet */
 	if (unlikely(pi->ptp_enable)) {
-- 
2.21.1