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From: Breno Leitao <leitao@debian.org>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	horms@kernel.org,
	dsahern@kernel.org,
	wireguard@lists.zx2c4.com (open list:WIREGUARD SECURE NETWORK TUNNEL)
Subject: [PATCH net-next v2 1/2] wireguard: Leverage core stats allocator
Date: Fri,  8 Mar 2024 03:27:44 -0800
Message-ID: <20240308112746.2290505-1-leitao@debian.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

With commit 34d21de99cea9 ("net: Move {l,t,d}stats allocation to core and
convert veth & vrf"), stats allocation could be done on net core
instead of in this driver.

With this new approach, the driver doesn't have to bother with error
handling (allocation failure checking, making sure free happens in the
right spot, etc). This is core responsibility now.

Remove the allocation in the wireguard driver and leverage the network
core allocation instead.

Signed-off-by: Breno Leitao <leitao@debian.org>
--
Changelog:

v2:
	* Setting dev->pcpu_stat_type was missing in v1 patch.
---
 drivers/net/wireguard/device.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c
index deb9636b0ecf..6aa071469e1c 100644
--- a/drivers/net/wireguard/device.c
+++ b/drivers/net/wireguard/device.c
@@ -262,7 +262,6 @@ static void wg_destruct(struct net_device *dev)
 	rcu_barrier(); /* Wait for all the peers to be actually freed. */
 	wg_ratelimiter_uninit();
 	memzero_explicit(&wg->static_identity, sizeof(wg->static_identity));
-	free_percpu(dev->tstats);
 	kvfree(wg->index_hashtable);
 	kvfree(wg->peer_hashtable);
 	mutex_unlock(&wg->device_update_lock);
@@ -297,6 +296,7 @@ static void wg_setup(struct net_device *dev)
 	dev->hw_enc_features |= WG_NETDEV_FEATURES;
 	dev->mtu = ETH_DATA_LEN - overhead;
 	dev->max_mtu = round_down(INT_MAX, MESSAGE_PADDING_MULTIPLE) - overhead;
+	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 
 	SET_NETDEV_DEVTYPE(dev, &device_type);
 
@@ -331,14 +331,10 @@ static int wg_newlink(struct net *src_net, struct net_device *dev,
 	if (!wg->index_hashtable)
 		goto err_free_peer_hashtable;
 
-	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
-	if (!dev->tstats)
-		goto err_free_index_hashtable;
-
 	wg->handshake_receive_wq = alloc_workqueue("wg-kex-%s",
 			WQ_CPU_INTENSIVE | WQ_FREEZABLE, 0, dev->name);
 	if (!wg->handshake_receive_wq)
-		goto err_free_tstats;
+		goto err_free_index_hashtable;
 
 	wg->handshake_send_wq = alloc_workqueue("wg-kex-%s",
 			WQ_UNBOUND | WQ_FREEZABLE, 0, dev->name);
@@ -397,8 +393,6 @@ static int wg_newlink(struct net *src_net, struct net_device *dev,
 	destroy_workqueue(wg->handshake_send_wq);
 err_destroy_handshake_receive:
 	destroy_workqueue(wg->handshake_receive_wq);
-err_free_tstats:
-	free_percpu(dev->tstats);
 err_free_index_hashtable:
 	kvfree(wg->index_hashtable);
 err_free_peer_hashtable:
-- 
2.43.0