mlx4_core: Allow protocol drivers to find corresponding interfaces

Add a mechanism for mlx4 protocol drivers to get a pointer to other
drivers's device objects.  For this, an exported function,
mlx4_get_protocol_dev() is added, which allows a driver to get some
other driver's device based on the protocol that the driver
implements.  Two protocols are added: MLX4_PROTOCOL_IB and
MLX4_PROTOCOL_EN.

This will be used in mlx4 IBoE support so that mlx4_ib can find the
corresponding mlx4_en netdev.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>

[ Clean up and rename a few things.  - Roland ]

Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/net/mlx4/intf.c b/drivers/net/mlx4/intf.c
index 555067802751..73c94fcdfddf 100644
--- a/drivers/net/mlx4/intf.c
+++ b/drivers/net/mlx4/intf.c
@@ -161,3 +161,24 @@ void mlx4_unregister_device(struct mlx4_dev *dev)
 
         mutex_unlock(&intf_mutex);
 }
+
+void *mlx4_get_protocol_dev(struct mlx4_dev *dev, enum mlx4_protocol proto, int port)
+{
+        struct mlx4_priv *priv = mlx4_priv(dev);
+        struct mlx4_device_context *dev_ctx;
+        unsigned long flags;
+        void *result = NULL;
+
+        spin_lock_irqsave(&priv->ctx_lock, flags);
+
+        list_for_each_entry(dev_ctx, &priv->ctx_list, list)
+                if (dev_ctx->intf->protocol == proto && dev_ctx->intf->get_dev) {
+                        result = dev_ctx->intf->get_dev(dev, dev_ctx->context, port);
+                        break;
+                }
+
+        spin_unlock_irqrestore(&priv->ctx_lock, flags);
+
+        return result;
+}
+EXPORT_SYMBOL_GPL(mlx4_get_protocol_dev);