dpll: move all dpll<>netdev helpers to dpll code

Older versions of GCC really want to know the full definition
of the type involved in rcu_assign_pointer().

struct dpll_pin is defined in a local header, net/core can't
reach it. Move all the netdev <> dpll code into dpll, where
the type is known. Otherwise we'd need multiple function calls
to jump between the compilation units.

This is the same problem the commit under fixes was trying to address,
but with rcu_assign_pointer() not rcu_dereference().

Some of the exports are not needed, networking core can't
be a module, we only need exports for the helpers used by
drivers.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/all/35a869c8-52e8-177-1d4d-e57578b99b6@linux-m68k.org/
Fixes: 640f41ed33 ("dpll: fix build failure due to rcu_dereference_check() on unknown type")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240305013532.694866-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/driver-api/dpll.rst

@@ -545,7 +545,7 @@ In such scenario, dpll device input signal shall be also configurable
 to drive dpll with signal recovered from the PHY netdevice.
 This is done by exposing a pin to the netdevice - attaching pin to the
 netdevice itself with
-``netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)``.
+``dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)``.
 Exposed pin id handle ``DPLL_A_PIN_ID`` is then identifiable by the user
 as it is attached to rtnetlink respond to get ``RTM_NEWLINK`` command in
 nested attribute ``IFLA_DPLL_PIN``.

drivers/dpll/dpll_core.c

@@ -42,11 +42,6 @@ struct dpll_pin_registration {
 	void *priv;
 };
 
-struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
-{
-	return rcu_dereference_rtnl(dev->dpll_pin);
-}
-
 struct dpll_device *dpll_device_get_by_id(int id)
 {
 	if (xa_get_mark(&dpll_device_xa, id, DPLL_REGISTERED))
@@ -513,6 +508,26 @@ err_pin_prop:
 	return ERR_PTR(ret);
 }
 
+static void dpll_netdev_pin_assign(struct net_device *dev, struct dpll_pin *dpll_pin)
+{
+	rtnl_lock();
+	rcu_assign_pointer(dev->dpll_pin, dpll_pin);
+	rtnl_unlock();
+}
+
+void dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin)
+{
+	WARN_ON(!dpll_pin);
+	dpll_netdev_pin_assign(dev, dpll_pin);
+}
+EXPORT_SYMBOL(dpll_netdev_pin_set);
+
+void dpll_netdev_pin_clear(struct net_device *dev)
+{
+	dpll_netdev_pin_assign(dev, NULL);
+}
+EXPORT_SYMBOL(dpll_netdev_pin_clear);
+
 /**
  * dpll_pin_get - find existing or create new dpll pin
  * @clock_id: clock_id of creator

drivers/dpll/dpll_netlink.c

@@ -8,6 +8,7 @@
  */
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/netdevice.h>
 #include <net/genetlink.h>
 #include "dpll_core.h"
 #include "dpll_netlink.h"
@@ -47,18 +48,6 @@ dpll_msg_add_dev_parent_handle(struct sk_buff *msg, u32 id)
 	return 0;
 }
 
-/**
- * dpll_msg_pin_handle_size - get size of pin handle attribute for given pin
- * @pin: pin pointer
- *
- * Return: byte size of pin handle attribute for given pin.
- */
-size_t dpll_msg_pin_handle_size(struct dpll_pin *pin)
-{
-	return pin ? nla_total_size(4) : 0; /* DPLL_A_PIN_ID */
-}
-EXPORT_SYMBOL_GPL(dpll_msg_pin_handle_size);
-
 /**
  * dpll_msg_add_pin_handle - attach pin handle attribute to a given message
  * @msg: pointer to sk_buff message to attach a pin handle
@@ -68,7 +57,7 @@ EXPORT_SYMBOL_GPL(dpll_msg_pin_handle_size);
  * * 0 - success
  * * -EMSGSIZE - no space in message to attach pin handle
  */
-int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin)
+static int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin)
 {
 	if (!pin)
 		return 0;
@@ -76,7 +65,28 @@ int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin)
 		return -EMSGSIZE;
 	return 0;
 }
-EXPORT_SYMBOL_GPL(dpll_msg_add_pin_handle);
+
+static struct dpll_pin *dpll_netdev_pin(const struct net_device *dev)
+{
+	return rcu_dereference_rtnl(dev->dpll_pin);
+}
+
+/**
+ * dpll_netdev_pin_handle_size - get size of pin handle attribute of a netdev
+ * @dev: netdev from which to get the pin
+ *
+ * Return: byte size of pin handle attribute, or 0 if @dev has no pin.
+ */
+size_t dpll_netdev_pin_handle_size(const struct net_device *dev)
+{
+	return dpll_netdev_pin(dev) ? nla_total_size(4) : 0; /* DPLL_A_PIN_ID */
+}
+
+int dpll_netdev_add_pin_handle(struct sk_buff *msg,
+			       const struct net_device *dev)
+{
+	return dpll_msg_add_pin_handle(msg, dpll_netdev_pin(dev));
+}
 
 static int
 dpll_msg_add_mode(struct sk_buff *msg, struct dpll_device *dpll,

drivers/net/ethernet/intel/ice/ice_dpll.c

@@ -1597,7 +1597,7 @@ static void ice_dpll_deinit_rclk_pin(struct ice_pf *pf)
 	}
 	if (WARN_ON_ONCE(!vsi || !vsi->netdev))
 		return;
-	netdev_dpll_pin_clear(vsi->netdev);
+	dpll_netdev_pin_clear(vsi->netdev);
 	dpll_pin_put(rclk->pin);
 }
 
@@ -1641,7 +1641,7 @@ ice_dpll_init_rclk_pins(struct ice_pf *pf, struct ice_dpll_pin *pin,
 	}
 	if (WARN_ON((!vsi || !vsi->netdev)))
 		return -EINVAL;
-	netdev_dpll_pin_set(vsi->netdev, pf->dplls.rclk.pin);
+	dpll_netdev_pin_set(vsi->netdev, pf->dplls.rclk.pin);
 
 	return 0;
 

drivers/net/ethernet/mellanox/mlx5/core/dpll.c

@@ -261,7 +261,7 @@ static void mlx5_dpll_netdev_dpll_pin_set(struct mlx5_dpll *mdpll,
 {
 	if (mdpll->tracking_netdev)
 		return;
-	netdev_dpll_pin_set(netdev, mdpll->dpll_pin);
+	dpll_netdev_pin_set(netdev, mdpll->dpll_pin);
 	mdpll->tracking_netdev = netdev;
 }
 
@@ -269,7 +269,7 @@ static void mlx5_dpll_netdev_dpll_pin_clear(struct mlx5_dpll *mdpll)
 {
 	if (!mdpll->tracking_netdev)
 		return;
-	netdev_dpll_pin_clear(mdpll->tracking_netdev);
+	dpll_netdev_pin_clear(mdpll->tracking_netdev);
 	mdpll->tracking_netdev = NULL;
 }
 

include/linux/dpll.h

@@ -122,15 +122,24 @@ struct dpll_pin_properties {
 };
 
 #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);
+void dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin);
+void dpll_netdev_pin_clear(struct net_device *dev);
+
+size_t dpll_netdev_pin_handle_size(const struct net_device *dev);
+int dpll_netdev_add_pin_handle(struct sk_buff *msg,
+			       const struct net_device *dev);
 #else
-static inline size_t dpll_msg_pin_handle_size(struct dpll_pin *pin)
+static inline void
+dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin) { }
+static inline void dpll_netdev_pin_clear(struct net_device *dev) { }
+
+static inline size_t dpll_netdev_pin_handle_size(const struct net_device *dev)
 {
 	return 0;
 }
 
-static inline int dpll_msg_add_pin_handle(struct sk_buff *msg, struct dpll_pin *pin)
+static inline int
+dpll_netdev_add_pin_handle(struct sk_buff *msg, const struct net_device *dev)
 {
 	return 0;
 }
@@ -169,13 +178,4 @@ int dpll_device_change_ntf(struct dpll_device *dpll);
 
 int dpll_pin_change_ntf(struct dpll_pin *pin);
 
-#if !IS_ENABLED(CONFIG_DPLL)
-static inline struct dpll_pin *netdev_dpll_pin(const struct net_device *dev)
-{
-	return NULL;
-}
-#else
-struct dpll_pin *netdev_dpll_pin(const struct net_device *dev);
-#endif
-
 #endif

include/linux/netdevice.h

@@ -79,8 +79,6 @@ struct xdp_buff;
 struct xdp_frame;
 struct xdp_metadata_ops;
 struct xdp_md;
-/* DPLL specific */
-struct dpll_pin;
 
 typedef u32 xdp_features_t;
 
@@ -4042,8 +4040,6 @@ int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name);
 int dev_get_port_parent_id(struct net_device *dev,
 			   struct netdev_phys_item_id *ppid, bool recurse);
 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b);
-void netdev_dpll_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin);
-void netdev_dpll_pin_clear(struct net_device *dev);
 
 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again);
 struct sk_buff *dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,

net/core/dev.c

@@ -9074,28 +9074,6 @@ 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();
-	rcu_assign_pointer(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.
  *

net/core/rtnetlink.c

@@ -1057,7 +1057,7 @@ 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));
+	size += dpll_netdev_pin_handle_size(dev);
 
 	return size;
 }
@@ -1792,7 +1792,7 @@ static int rtnl_fill_dpll_pin(struct sk_buff *skb,
 	if (!dpll_pin_nest)
 		return -EMSGSIZE;
 
-	ret = dpll_msg_add_pin_handle(skb, netdev_dpll_pin(dev));
+	ret = dpll_netdev_add_pin_handle(skb, dev);
 	if (ret < 0)
 		goto nest_cancel;