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>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index 2202310c10cd..bbc480cd2932 100644
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -101,6 +101,21 @@ struct dpll_pin_properties {
 	struct dpll_pin_frequency *freq_supported;
 };
 
+#if IS_ENABLED(CONFIG_DPLL)
+size_t dpll_msg_pin_handle_size(struct dpll_pin *pin);
+int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin);
+#else
+static inline size_t dpll_msg_pin_handle_size(struct dpll_pin *pin)
+{
+	return 0;
+}
+
+static inline int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin)
+{
+	return 0;
+}
+#endif
+
 struct dpll_device *
 dpll_device_get(u64 clock_id, u32 dev_driver_id, struct module *module);