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>

3 files changed, 42 insertions, 3 deletions

diff --git a/drivers/net/mlx4/en_main.c b/drivers/net/mlx4/en_main.c
index 97934f1ec53a..b2df3eeb1598 100644
--- a/drivers/net/mlx4/en_main.c
+++ b/drivers/net/mlx4/en_main.c
@@ -124,6 +124,13 @@ static int mlx4_en_get_profile(struct mlx4_en_dev *mdev)
         return 0;
 }
 
+static void *mlx4_en_get_netdev(struct mlx4_dev *dev, void *ctx, u8 port)
+{
+        struct mlx4_en_dev *endev = ctx;
+
+        return endev->pndev[port];
+}
+
 static void mlx4_en_event(struct mlx4_dev *dev, void *endev_ptr,
                           enum mlx4_dev_event event, int port)
 {
@@ -282,9 +289,11 @@ err_free_res:
 }
 
 static struct mlx4_interface mlx4_en_interface = {
-        .add    = mlx4_en_add,
-        .remove = mlx4_en_remove,
-        .event  = mlx4_en_event,
+        .add            = mlx4_en_add,
+        .remove         = mlx4_en_remove,
+        .event          = mlx4_en_event,
+        .get_dev        = mlx4_en_get_netdev,
+        .protocol       = MLX4_PROTOCOL_EN,
 };
 
 static int __init mlx4_en_init(void)
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);
diff --git a/include/linux/mlx4/driver.h b/include/linux/mlx4/driver.h
index 53c5fdb6eac4..f407cd4bfb34 100644
--- a/include/linux/mlx4/driver.h
+++ b/include/linux/mlx4/driver.h
@@ -44,15 +44,24 @@ enum mlx4_dev_event {
         MLX4_DEV_EVENT_PORT_REINIT,
 };
 
+enum mlx4_protocol {
+        MLX4_PROTOCOL_IB,
+        MLX4_PROTOCOL_EN,
+};
+
 struct mlx4_interface {
         void *                  (*add)   (struct mlx4_dev *dev);
         void                    (*remove)(struct mlx4_dev *dev, void *context);
         void                    (*event) (struct mlx4_dev *dev, void *context,
                                           enum mlx4_dev_event event, int port);
+        void *                  (*get_dev)(struct mlx4_dev *dev, void *context, u8 port);
         struct list_head        list;
+        enum mlx4_protocol      protocol;
 };
 
 int mlx4_register_interface(struct mlx4_interface *intf);
 void mlx4_unregister_interface(struct mlx4_interface *intf);
 
+void *mlx4_get_protocol_dev(struct mlx4_dev *dev, enum mlx4_protocol proto, int port);
+
 #endif /* MLX4_DRIVER_H */