net: hsr: Create and export hsr_get_port_ndev()

Create an API to get the net_device to the slave port of HSR device. The
API will take hsr net_device and enum hsr_port_type for which we want the
net_device as arguments.

This API can be used by client drivers who support HSR and want to get
the net_devcie of slave ports from the hsr device. Export this API for
the same.

This API needs the enum hsr_port_type to be accessible by the drivers using
hsr. Move the enum hsr_port_type from net/hsr/hsr_main.h to
include/linux/if_hsr.h for the same.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

include/linux/if_hsr.h

@@ -13,6 +13,15 @@ enum hsr_version {
 	PRP_V1,
 };
 
+enum hsr_port_type {
+	HSR_PT_NONE = 0,	/* Must be 0, used by framereg */
+	HSR_PT_SLAVE_A,
+	HSR_PT_SLAVE_B,
+	HSR_PT_INTERLINK,
+	HSR_PT_MASTER,
+	HSR_PT_PORTS,	/* This must be the last item in the enum */
+};
+
 /* HSR Tag.
  * As defined in IEC-62439-3:2010, the HSR tag is really { ethertype = 0x88FB,
  * path, LSDU_size, sequence Nr }. But we let eth_header() create { h_dest,
@@ -32,6 +41,8 @@ struct hsr_tag {
 #if IS_ENABLED(CONFIG_HSR)
 extern bool is_hsr_master(struct net_device *dev);
 extern int hsr_get_version(struct net_device *dev, enum hsr_version *ver);
+struct net_device *hsr_get_port_ndev(struct net_device *ndev,
+				     enum hsr_port_type pt);
 #else
 static inline bool is_hsr_master(struct net_device *dev)
 {
@@ -42,6 +53,12 @@ static inline int hsr_get_version(struct net_device *dev,
 {
 	return -EINVAL;
 }
+
+static inline struct net_device *hsr_get_port_ndev(struct net_device *ndev,
+						   enum hsr_port_type pt)
+{
+	return ERR_PTR(-EINVAL);
+}
 #endif /* CONFIG_HSR */
 
 #endif /*_LINUX_IF_HSR_H_*/

net/hsr/hsr_device.c

@@ -663,6 +663,19 @@ bool is_hsr_master(struct net_device *dev)
 }
 EXPORT_SYMBOL(is_hsr_master);
 
+struct net_device *hsr_get_port_ndev(struct net_device *ndev,
+				     enum hsr_port_type pt)
+{
+	struct hsr_priv *hsr = netdev_priv(ndev);
+	struct hsr_port *port;
+
+	hsr_for_each_port(hsr, port)
+		if (port->type == pt)
+			return port->dev;
+	return NULL;
+}
+EXPORT_SYMBOL(hsr_get_port_ndev);
+
 /* Default multicast address for HSR Supervision frames */
 static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 	0x01, 0x15, 0x4e, 0x00, 0x01, 0x00

net/hsr/hsr_main.h

@@ -121,15 +121,6 @@ struct hsrv1_ethhdr_sp {
 	struct hsr_sup_tag	hsr_sup;
 } __packed;
 
-enum hsr_port_type {
-	HSR_PT_NONE = 0,	/* Must be 0, used by framereg */
-	HSR_PT_SLAVE_A,
-	HSR_PT_SLAVE_B,
-	HSR_PT_INTERLINK,
-	HSR_PT_MASTER,
-	HSR_PT_PORTS,	/* This must be the last item in the enum */
-};
-
 /* PRP Redunancy Control Trailor (RCT).
  * As defined in IEC-62439-4:2012, the PRP RCT is really { sequence Nr,
  * Lan indentifier (LanId), LSDU_size and PRP_suffix = 0x88FB }.