[PATCH 02/22] NTB: Add peer indexed ports NTB API

[Serge Semin]

Add new port-index NTB API. Additionally lets get rid of Primary and
Secondary topologies, since port-number can be effectively used instead.

Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>

---
 include/linux/ntb.h | 101 ++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 79 insertions(+), 22 deletions(-)

diff --git a/include/linux/ntb.h b/include/linux/ntb.h
index 5d1f260..0941a43 100644
--- a/include/linux/ntb.h
+++ b/include/linux/ntb.h
@@ -64,37 +64,21 @@ struct pci_dev;
 /**
  * enum ntb_topo - NTB connection topology
  * @NTB_TOPO_NONE:	Topology is unknown or invalid.
- * @NTB_TOPO_PRI:	On primary side of local ntb.
- * @NTB_TOPO_SEC:	On secondary side of remote ntb.
- * @NTB_TOPO_B2B_USD:	On primary side of local ntb upstream of remote ntb.
- * @NTB_TOPO_B2B_DSD:	On primary side of local ntb downstream of remote ntb.
+ * @NTB_TOPO_P2P:	Simple port-to-port NTB topology
+ * @NTB_TOPO_B2B:	Bridge-to-bridge NTB topology
  */
 enum ntb_topo {
 	NTB_TOPO_NONE = -1,
-	NTB_TOPO_PRI,
-	NTB_TOPO_SEC,
-	NTB_TOPO_B2B_USD,
-	NTB_TOPO_B2B_DSD,
+	NTB_TOPO_P2P,
+	NTB_TOPO_B2B
 };
 
-static inline int ntb_topo_is_b2b(enum ntb_topo topo)
-{
-	switch ((int)topo) {
-	case NTB_TOPO_B2B_USD:
-	case NTB_TOPO_B2B_DSD:
-		return 1;
-	}
-	return 0;
-}
-
 static inline char *ntb_topo_string(enum ntb_topo topo)
 {
 	switch (topo) {
 	case NTB_TOPO_NONE:	return "NTB_TOPO_NONE";
-	case NTB_TOPO_PRI:	return "NTB_TOPO_PRI";
-	case NTB_TOPO_SEC:	return "NTB_TOPO_SEC";
-	case NTB_TOPO_B2B_USD:	return "NTB_TOPO_B2B_USD";
-	case NTB_TOPO_B2B_DSD:	return "NTB_TOPO_B2B_DSD";
+	case NTB_TOPO_P2P:	return "NTB_TOPO_P2P";
+	case NTB_TOPO_B2B:	return "NTB_TOPO_B2B";
 	}
 	return "NTB_TOPO_INVALID";
 }
@@ -179,6 +163,10 @@ static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)
 
 /**
  * struct ntb_ctx_ops - ntb device operations
+ * @port_number:	See ntb_port_number().
+ * @peer_port_count:	See ntb_peer_port_count().
+ * @peer_port_number:	See ntb_peer_port_number().
+ * @peer_port_idx:	See ntb_peer_port_idx().
  * @link_is_up:		See ntb_link_is_up().
  * @link_enable:	See ntb_link_enable().
  * @link_disable:	See ntb_link_disable().
@@ -212,6 +200,11 @@ 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 (*port_number)(struct ntb_dev *ntb);
+	int (*peer_port_count)(struct ntb_dev *ntb);
+	int (*peer_port_number)(struct ntb_dev *ntb, int pidx);
+	int (*peer_port_idx)(struct ntb_dev *ntb, int port);
+
 	int (*link_is_up)(struct ntb_dev *ntb,
 			  enum ntb_speed *speed, enum ntb_width *width);
 	int (*link_enable)(struct ntb_dev *ntb,
@@ -265,6 +258,10 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
 {
 	/* commented callbacks are not required: */
 	return
+		ops->port_number			&&
+		ops->peer_port_count			&&
+		ops->peer_port_number			&&
+		ops->peer_port_idx			&&
 		ops->link_is_up				&&
 		ops->link_enable			&&
 		ops->link_disable			&&
@@ -319,6 +316,7 @@ struct ntb_client {
  * @dev:		Linux device object.
  * @pdev:		Pci device entry of the ntb.
  * @topo:		Detected topology of the ntb.
+ * @port:		Local port of the ntb.
  * @ops:		See &ntb_dev_ops.
  * @ctx:		See &ntb_ctx_ops.
  * @ctx_ops:		See &ntb_ctx_ops.
@@ -327,6 +325,7 @@ struct ntb_dev {
 	struct device			dev;
 	struct pci_dev			*pdev;
 	enum ntb_topo			topo;
+	int				port;
 	const struct ntb_dev_ops	*ops;
 	void				*ctx;
 	const struct ntb_ctx_ops	*ctx_ops;
@@ -442,6 +441,64 @@ void ntb_link_event(struct ntb_dev *ntb);
 void ntb_db_event(struct ntb_dev *ntb, int vector);
 
 /**
+ * ntb_port_number() - get the local port number
+ * @ntb:	NTB device context.
+ *
+ * Hardware must support at least simple two-ports topology
+ *
+ * Return: the local port number
+ */
+static inline int ntb_port_number(struct ntb_dev *ntb)
+{
+	return ntb->ops->port_number(ntb);
+}
+
+/**
+ * ntb_peer_port_count() - get the number of peer device ports
+ * @ntb:	NTB device context.
+ *
+ * Hardware may support an access to memory of several remote domains
+ * over multi-port NTB devices. This method returns the number of peers,
+ * local device can have shared memory with.
+ *
+ * Return: the number of peer ports
+ */
+static inline int ntb_peer_port_count(struct ntb_dev *ntb)
+{
+	return ntb->ops->peer_port_count(ntb);
+}
+
+/**
+ * ntb_peer_port_number() - get the peer port by given index
+ * @ntb:	NTB device context.
+ * @pidx:	Peer port index.
+ *
+ * Peer ports are continuously enumerated by NTB API logic, so this methods
+ * lets to retrieve port real number by its index.
+ *
+ * Return: the peer device port or negative value indicating an error
+ */
+static inline int ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
+{
+	return ntb->ops->peer_port_number(ntb, pidx);
+}
+
+/**
+ * ntb_peer_port_idx() - get the peer device port index by given port number
+ * @ntb:	NTB device context.
+ * @port:	Peer port number.
+ *
+ * Inverse operation of ntb_peer_port_number(), so one can get port index
+ * by its port number.
+ *
+ * Return: the peer port index or negative value indicating an error
+ */
+static inline int ntb_peer_port_idx(struct ntb_dev *ntb, int port)
+{
+	return ntb->ops->peer_port_idx(ntb, port);
+}
+
+/**
  * ntb_link_is_up() - get the current ntb link state
  * @ntb:	NTB device context.
  * @speed:	OUT - The link speed expressed as PCIe generation number.
-- 
2.6.6