NTB: Make link-state API being declared first

Since link operations are usually performed before memory window access
operations, it's logically better to declare link-related API before any
of MW/Doorbell/Scratchpad methods.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

include/linux/ntb.h

@@ -179,13 +179,13 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)
 
 /**
  * struct ntb_ctx_ops - ntb device operations
+ * @link_is_up:		See ntb_link_is_up().
+ * @link_enable:	See ntb_link_enable().
+ * @link_disable:	See ntb_link_disable().
  * @mw_count:		See ntb_mw_count().
  * @mw_get_range:	See ntb_mw_get_range().
  * @mw_set_trans:	See ntb_mw_set_trans().
  * @mw_clear_trans:	See ntb_mw_clear_trans().
- * @link_is_up:		See ntb_link_is_up().
- * @link_enable:	See ntb_link_enable().
- * @link_disable:	See ntb_link_disable().
  * @db_is_unsafe:	See ntb_db_is_unsafe().
  * @db_valid_mask:	See ntb_db_valid_mask().
  * @db_vector_count:	See ntb_db_vector_count().
@@ -212,6 +212,12 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)
  * @peer_spad_write:	See ntb_peer_spad_write().
  */
 struct ntb_dev_ops {
+	int (*link_is_up)(struct ntb_dev *ntb,
+			  enum ntb_speed *speed, enum ntb_width *width);
+	int (*link_enable)(struct ntb_dev *ntb,
+			   enum ntb_speed max_speed, enum ntb_width max_width);
+	int (*link_disable)(struct ntb_dev *ntb);
+
 	int (*mw_count)(struct ntb_dev *ntb);
 	int (*mw_get_range)(struct ntb_dev *ntb, int idx,
 			    phys_addr_t *base, resource_size_t *size,
@@ -220,12 +226,6 @@ struct ntb_dev_ops {
 			    dma_addr_t addr, resource_size_t size);
 	int (*mw_clear_trans)(struct ntb_dev *ntb, int idx);
 
-	int (*link_is_up)(struct ntb_dev *ntb,
-			  enum ntb_speed *speed, enum ntb_width *width);
-	int (*link_enable)(struct ntb_dev *ntb,
-			   enum ntb_speed max_speed, enum ntb_width max_width);
-	int (*link_disable)(struct ntb_dev *ntb);
-
 	int (*db_is_unsafe)(struct ntb_dev *ntb);
 	u64 (*db_valid_mask)(struct ntb_dev *ntb);
 	int (*db_vector_count)(struct ntb_dev *ntb);
@@ -265,13 +265,14 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
 {
 	/* commented callbacks are not required: */
 	return
+		ops->link_is_up				&&
+		ops->link_enable			&&
+		ops->link_disable			&&
 		ops->mw_count				&&
 		ops->mw_get_range			&&
 		ops->mw_set_trans			&&
 		/* ops->mw_clear_trans			&& */
-		ops->link_is_up				&&
-		ops->link_enable			&&
-		ops->link_disable			&&
+
 		/* ops->db_is_unsafe			&& */
 		ops->db_valid_mask			&&
 
@@ -440,6 +441,62 @@ void ntb_link_event(struct ntb_dev *ntb);
  */
 void ntb_db_event(struct ntb_dev *ntb, int vector);
 
+/**
+ * ntb_link_is_up() - get the current ntb link state
+ * @ntb:	NTB device context.
+ * @speed:	OUT - The link speed expressed as PCIe generation number.
+ * @width:	OUT - The link width expressed as the number of PCIe lanes.
+ *
+ * Get the current state of the ntb link.  It is recommended to query the link
+ * state once after every link event.  It is safe to query the link state in
+ * the context of the link event callback.
+ *
+ * Return: One if the link is up, zero if the link is down, otherwise a
+ *		negative value indicating the error number.
+ */
+static inline int ntb_link_is_up(struct ntb_dev *ntb,
+				 enum ntb_speed *speed, enum ntb_width *width)
+{
+	return ntb->ops->link_is_up(ntb, speed, width);
+}
+
+/**
+ * ntb_link_enable() - enable the link on the secondary side of the ntb
+ * @ntb:	NTB device context.
+ * @max_speed:	The maximum link speed expressed as PCIe generation number.
+ * @max_width:	The maximum link width expressed as the number of PCIe lanes.
+ *
+ * Enable the link on the secondary side of the ntb.  This can only be done
+ * from the primary side of the ntb in primary or b2b topology.  The ntb device
+ * should train the link to its maximum speed and width, or the requested speed
+ * and width, whichever is smaller, if supported.
+ *
+ * Return: Zero on success, otherwise an error number.
+ */
+static inline int ntb_link_enable(struct ntb_dev *ntb,
+				  enum ntb_speed max_speed,
+				  enum ntb_width max_width)
+{
+	return ntb->ops->link_enable(ntb, max_speed, max_width);
+}
+
+/**
+ * ntb_link_disable() - disable the link on the secondary side of the ntb
+ * @ntb:	NTB device context.
+ *
+ * Disable the link on the secondary side of the ntb.  This can only be
+ * done from the primary side of the ntb in primary or b2b topology.  The ntb
+ * device should disable the link.  Returning from this call must indicate that
+ * a barrier has passed, though with no more writes may pass in either
+ * direction across the link, except if this call returns an error number.
+ *
+ * Return: Zero on success, otherwise an error number.
+ */
+static inline int ntb_link_disable(struct ntb_dev *ntb)
+{
+	return ntb->ops->link_disable(ntb);
+}
+
 /**
  * ntb_mw_count() - get the number of memory windows
  * @ntb:	NTB device context.
@@ -516,62 +573,6 @@ static inline int ntb_mw_clear_trans(struct ntb_dev *ntb, int idx)
 	return ntb->ops->mw_clear_trans(ntb, idx);
 }
 
-/**
- * ntb_link_is_up() - get the current ntb link state
- * @ntb:	NTB device context.
- * @speed:	OUT - The link speed expressed as PCIe generation number.
- * @width:	OUT - The link width expressed as the number of PCIe lanes.
- *
- * Get the current state of the ntb link.  It is recommended to query the link
- * state once after every link event.  It is safe to query the link state in
- * the context of the link event callback.
- *
- * Return: One if the link is up, zero if the link is down, otherwise a
- *		negative value indicating the error number.
- */
-static inline int ntb_link_is_up(struct ntb_dev *ntb,
-				 enum ntb_speed *speed, enum ntb_width *width)
-{
-	return ntb->ops->link_is_up(ntb, speed, width);
-}
-
-/**
- * ntb_link_enable() - enable the link on the secondary side of the ntb
- * @ntb:	NTB device context.
- * @max_speed:	The maximum link speed expressed as PCIe generation number.
- * @max_width:	The maximum link width expressed as the number of PCIe lanes.
- *
- * Enable the link on the secondary side of the ntb.  This can only be done
- * from the primary side of the ntb in primary or b2b topology.  The ntb device
- * should train the link to its maximum speed and width, or the requested speed
- * and width, whichever is smaller, if supported.
- *
- * Return: Zero on success, otherwise an error number.
- */
-static inline int ntb_link_enable(struct ntb_dev *ntb,
-				  enum ntb_speed max_speed,
-				  enum ntb_width max_width)
-{
-	return ntb->ops->link_enable(ntb, max_speed, max_width);
-}
-
-/**
- * ntb_link_disable() - disable the link on the secondary side of the ntb
- * @ntb:	NTB device context.
- *
- * Disable the link on the secondary side of the ntb.  This can only be
- * done from the primary side of the ntb in primary or b2b topology.  The ntb
- * device should disable the link.  Returning from this call must indicate that
- * a barrier has passed, though with no more writes may pass in either
- * direction across the link, except if this call returns an error number.
- *
- * Return: Zero on success, otherwise an error number.
- */
-static inline int ntb_link_disable(struct ntb_dev *ntb)
-{
-	return ntb->ops->link_disable(ntb);
-}
-
 /**
  * ntb_db_is_unsafe() - check if it is safe to use hardware doorbell
  * @ntb:	NTB device context.