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: 640f41ed33b5 ("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>

1 files changed, 24 insertions, 14 deletions

diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index 4ca9ad16cd95..b57355e0c214 100644
--- a/drivers/dpll/dpll_netlink.c
+++ b/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"
@@ -48,18 +49,6 @@ dpll_msg_add_dev_parent_handle(struct sk_buff *msg, u32 id)
 }
 
 /**
- * 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
  * @pin: pin pointer
@@ -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,