genetlink: remove linux/genetlink.h

genetlink.h is a shell of what used to be a combined uAPI
and kernel header over a decade ago. It has fewer than
10 lines of code. Merge it into net/genetlink.h.
In some ways it'd be better to keep the combined header
under linux/ but it would make looking through git history
harder.

Acked-by: Sven Eckelmann <sven@narfation.org>
Link: https://lore.kernel.org/r/20240329175710.291749-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/wireguard/main.c

@@ -14,7 +14,7 @@
 
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/genetlink.h>
+#include <net/genetlink.h>
 #include <net/rtnetlink.h>
 
 static int __init wg_mod_init(void)

include/linux/genetlink.h

@@ -1,14 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __LINUX_GENERIC_NETLINK_H
-#define __LINUX_GENERIC_NETLINK_H
-
-#include <uapi/linux/genetlink.h>
-
-/* All generic netlink requests are serialized by a global lock.  */
-extern void genl_lock(void);
-extern void genl_unlock(void);
-
-#define MODULE_ALIAS_GENL_FAMILY(family)\
- MODULE_ALIAS_NET_PF_PROTO_NAME(PF_NETLINK, NETLINK_GENERIC, "-family-" family)
-
-#endif	/* __LINUX_GENERIC_NETLINK_H */

include/linux/genl_magic_struct.h

@@ -15,8 +15,8 @@
 #endif
 
 #include <linux/args.h>
-#include <linux/genetlink.h>
 #include <linux/types.h>
+#include <net/genetlink.h>
 
 extern int CONCATENATE(GENL_MAGIC_FAMILY, _genl_register)(void);
 extern void CONCATENATE(GENL_MAGIC_FAMILY, _genl_unregister)(void);

include/net/genetlink.h

@@ -2,12 +2,20 @@
 #ifndef __NET_GENERIC_NETLINK_H
 #define __NET_GENERIC_NETLINK_H
 
-#include <linux/genetlink.h>
+#include <linux/net.h>
 #include <net/netlink.h>
 #include <net/net_namespace.h>
+#include <uapi/linux/genetlink.h>
 
 #define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
 
+/* Non-parallel generic netlink requests are serialized by a global lock. */
+void genl_lock(void);
+void genl_unlock(void);
+
+#define MODULE_ALIAS_GENL_FAMILY(family) \
+ MODULE_ALIAS_NET_PF_PROTO_NAME(PF_NETLINK, NETLINK_GENERIC, "-family-" family)
+
 /* Binding to multicast group requires %CAP_NET_ADMIN */
 #define GENL_MCAST_CAP_NET_ADMIN	BIT(0)
 /* Binding to multicast group requires %CAP_SYS_ADMIN */

net/batman-adv/main.c

@@ -14,7 +14,6 @@
 #include <linux/crc32c.h>
 #include <linux/device.h>
 #include <linux/errno.h>
-#include <linux/genetlink.h>
 #include <linux/gfp.h>
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>
@@ -38,6 +37,7 @@
 #include <linux/string.h>
 #include <linux/workqueue.h>
 #include <net/dsfield.h>
+#include <net/genetlink.h>
 #include <net/rtnetlink.h>
 #include <uapi/linux/batadv_packet.h>
 #include <uapi/linux/batman_adv.h>

net/batman-adv/netlink.c

@@ -15,7 +15,6 @@
 #include <linux/cache.h>
 #include <linux/err.h>
 #include <linux/errno.h>
-#include <linux/genetlink.h>
 #include <linux/gfp.h>
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>

net/openvswitch/datapath.c

@@ -15,7 +15,6 @@
 #include <linux/delay.h>
 #include <linux/time.h>
 #include <linux/etherdevice.h>
-#include <linux/genetlink.h>
 #include <linux/kernel.h>
 #include <linux/kthread.h>
 #include <linux/mutex.h>