netdev: expose DPLL pin handle for netdevice

In case netdevice represents a SyncE port, the user needs to understand
the connection between netdevice and associated DPLL pin. There might me
multiple netdevices pointing to the same pin, in case of VF/SF
implementation.

Add a IFLA Netlink attribute to nest the DPLL pin handle, similar to
how it is implemented for devlink port. Add a struct dpll_pin pointer
to netdev and protect access to it by RTNL. Expose netdev_dpll_pin_set()
and netdev_dpll_pin_clear() helpers to the drivers so they can set/clear
the DPLL pin relationship to netdev.

Note that during the lifetime of struct dpll_pin the pin handle does not
change. Therefore it is save to access it lockless. It is drivers
responsibility to call netdev_dpll_pin_clear() before dpll_pin_put().

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 58 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index ccff2b6ef958..cc03a5758d2d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9023,6 +9023,28 @@ bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
 }
 EXPORT_SYMBOL(netdev_port_same_parent_id);
 
+static void netdev_dpll_pin_assign(struct net_device *dev, struct dpll_pin *dpll_pin)
+{
+#if IS_ENABLED(CONFIG_DPLL)
+	rtnl_lock();
+	dev->dpll_pin = dpll_pin;
+	rtnl_unlock();
+#endif
+}
+
+void netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)
+{
+	WARN_ON(!dpll_pin);
+	netdev_dpll_pin_assign(dev, dpll_pin);
+}
+EXPORT_SYMBOL(netdev_dpll_pin_set);
+
+void netdev_dpll_pin_clear(struct net_device *dev)
+{
+	netdev_dpll_pin_assign(dev, NULL);
+}
+EXPORT_SYMBOL(netdev_dpll_pin_clear);
+
 /**
  *	dev_change_proto_down - set carrier according to proto_down.
  *
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4a2ec33bfb51..7452a6d190c5 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -57,6 +57,7 @@
 #if IS_ENABLED(CONFIG_IPV6)
 #include <net/addrconf.h>
 #endif
+#include <linux/dpll.h>
 
 #include "dev.h"
 
@@ -1055,6 +1056,15 @@ static size_t rtnl_devlink_port_size(const struct net_device *dev)
 	return size;
 }
 
+static size_t rtnl_dpll_pin_size(const struct net_device *dev)
+{
+	size_t size = nla_total_size(0); /* nest IFLA_DPLL_PIN */
+
+	size += dpll_msg_pin_handle_size(netdev_dpll_pin(dev));
+
+	return size;
+}
+
 static noinline size_t if_nlmsg_size(const struct net_device *dev,
 				     u32 ext_filter_mask)
 {
@@ -1111,6 +1121,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + rtnl_prop_list_size(dev)
 	       + nla_total_size(MAX_ADDR_LEN) /* IFLA_PERM_ADDRESS */
 	       + rtnl_devlink_port_size(dev)
+	       + rtnl_dpll_pin_size(dev)
 	       + 0;
 }
 
@@ -1774,6 +1785,28 @@ nest_cancel:
 	return ret;
 }
 
+static int rtnl_fill_dpll_pin(struct sk_buff *skb,
+			      const struct net_device *dev)
+{
+	struct nlattr *dpll_pin_nest;
+	int ret;
+
+	dpll_pin_nest = nla_nest_start(skb, IFLA_DPLL_PIN);
+	if (!dpll_pin_nest)
+		return -EMSGSIZE;
+
+	ret = dpll_msg_add_pin_handle(skb, netdev_dpll_pin(dev));
+	if (ret < 0)
+		goto nest_cancel;
+
+	nla_nest_end(skb, dpll_pin_nest);
+	return 0;
+
+nest_cancel:
+	nla_nest_cancel(skb, dpll_pin_nest);
+	return ret;
+}
+
 static int rtnl_fill_ifinfo(struct sk_buff *skb,
 			    struct net_device *dev, struct net *src_net,
 			    int type, u32 pid, u32 seq, u32 change,
@@ -1916,6 +1949,9 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 	if (rtnl_fill_devlink_port(skb, dev))
 		goto nla_put_failure;
 
+	if (rtnl_fill_dpll_pin(skb, dev))
+		goto nla_put_failure;
+
 	nlmsg_end(skb, nlh);
 	return 0;