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From: Breno Leitao <leitao@debian.org>
To: kuba@kernel.org,
	davem@davemloft.net,
	pabeni@redhat.com,
	edumazet@google.com,
	=?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>,
	Oliver Neukum <oneukum@suse.com>
Cc: linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org,
	linux-usb@vger.kernel.org (open list:USB NETWORKING DRIVERS)
Subject: [PATCH net-next 1/2] net: usb: qmi_wwan: Leverage core stats allocator
Date: Tue,  9 Apr 2024 06:33:05 -0700
Message-ID: <20240409133307.2058099-1-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 qmi_wwan driver and leverage the network
core allocation instead.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
PS: This was compiled-tested only due to lack of hardware.
---
 drivers/net/usb/qmi_wwan.c | 8 +-------
 drivers/net/usb/usbnet.c   | 1 +
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index e2e181378f41..5528a9c2b9d6 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -133,6 +133,7 @@ static void qmimux_setup(struct net_device *dev)
 	dev->flags           = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 	dev->netdev_ops      = &qmimux_netdev_ops;
 	dev->mtu             = 1500;
+	dev->pcpu_stat_type  = NETDEV_PCPU_STAT_TSTATS;
 	dev->needs_free_netdev = true;
 }
 
@@ -257,12 +258,6 @@ static int qmimux_register_device(struct net_device *real_dev, u8 mux_id)
 	priv->mux_id = mux_id;
 	priv->real_dev = real_dev;
 
-	new_dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
-	if (!new_dev->tstats) {
-		err = -ENOBUFS;
-		goto out_free_newdev;
-	}
-
 	new_dev->sysfs_groups[0] = &qmi_wwan_sysfs_qmimux_attr_group;
 
 	err = register_netdevice(new_dev);
@@ -295,7 +290,6 @@ static void qmimux_unregister_device(struct net_device *dev,
 	struct qmimux_priv *priv = netdev_priv(dev);
 	struct net_device *real_dev = priv->real_dev;
 
-	free_percpu(dev->tstats);
 	netdev_upper_dev_unlink(real_dev, dev);
 	unregister_netdevice_queue(dev, head);
 
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index e84efa661589..f3f7f686fe9c 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1733,6 +1733,7 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
 	dev->hard_mtu = net->mtu + net->hard_header_len;
 	net->min_mtu = 0;
 	net->max_mtu = ETH_MAX_MTU;
+	net->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 
 	net->netdev_ops = &usbnet_netdev_ops;
 	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
-- 
2.43.0