mlx4_en: Added self diagnostics test implementation

The selftest includes 5 features:
1. Interrupt test: Executing commands and receiving command completion
   on all our interrupt vectors.
2. Link test: Verifying we are connected to valid link partner.
3. Speed test: Check that we negotiated link speed correctly.
4. Registers test: Activate HW health check command.
5. Loopback test: Send a packet on loopback interface and catch it on RX side.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/net/mlx4/en_rx.c b/drivers/net/mlx4/en_rx.c
index 7a5123c4a366..f421a3d42723 100644
--- a/drivers/net/mlx4/en_rx.c
+++ b/drivers/net/mlx4/en_rx.c
@@ -541,6 +541,21 @@ static struct sk_buff *mlx4_en_rx_skb(struct mlx4_en_priv *priv,
         return skb;
 }
 
+static void validate_loopback(struct mlx4_en_priv *priv, struct sk_buff *skb)
+{
+        int i;
+        int offset = ETH_HLEN;
+
+        for (i = 0; i < MLX4_LOOPBACK_TEST_PAYLOAD; i++, offset++) {
+                if (*(skb->data + offset) != (unsigned char) (i & 0xff))
+                        goto out_loopback;
+        }
+        /* Loopback found */
+        priv->loopback_ok = 1;
+
+out_loopback:
+        dev_kfree_skb_any(skb);
+}
 
 int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int budget)
 {
@@ -655,6 +670,11 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
                         goto next;
                 }
 
+                if (unlikely(priv->validate_loopback)) {
+                        validate_loopback(priv, skb);
+                        goto next;
+                }
+
                 skb->ip_summed = ip_summed;
                 skb->protocol = eth_type_trans(skb, dev);
                 skb_record_rx_queue(skb, cq->ring);