bpf: Move offload initialization into late_initcall

So we don't have to initialize it manually from several paths.

Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-4-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

kernel/bpf/offload.c

@@ -56,7 +56,6 @@ static const struct rhashtable_params offdevs_params = {
 };
 
 static struct rhashtable offdevs;
-static bool offdevs_inited;
 
 static int bpf_dev_offload_check(struct net_device *netdev)
 {
@@ -72,8 +71,6 @@ bpf_offload_find_netdev(struct net_device *netdev)
 {
 	lockdep_assert_held(&bpf_devs_lock);
 
-	if (!offdevs_inited)
-		return NULL;
 	return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
 }
 
@@ -673,18 +670,6 @@ struct bpf_offload_dev *
 bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv)
 {
 	struct bpf_offload_dev *offdev;
-	int err;
-
-	down_write(&bpf_devs_lock);
-	if (!offdevs_inited) {
-		err = rhashtable_init(&offdevs, &offdevs_params);
-		if (err) {
-			up_write(&bpf_devs_lock);
-			return ERR_PTR(err);
-		}
-		offdevs_inited = true;
-	}
-	up_write(&bpf_devs_lock);
 
 	offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
 	if (!offdev)
@@ -710,3 +695,10 @@ void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev)
 	return offdev->priv;
 }
 EXPORT_SYMBOL_GPL(bpf_offload_dev_priv);
+
+static int __init bpf_offload_init(void)
+{
+	return rhashtable_init(&offdevs, &offdevs_params);
+}
+
+late_initcall(bpf_offload_init);