From f9027f88f7d1dc2b0ed1afbf28f22992d72d7efe Mon Sep 17 00:00:00 2001 From: Zhaoping Shu Date: Thu, 3 Nov 2022 19:08:49 +0800 Subject: net: wwan: iosm: Remove unnecessary if_mutex lock These WWAN network interface operations (create/delete/open/close) are already protected by RTNL lock, i.e., wwan_ops.newlink(), wwan_ops.dellink(), net_device_ops.ndo_open() and net_device.ndo_stop() are called with RTNL lock held. Therefore, this patch removes the unnecessary if_mutex. Signed-off-by: Zhaoping Shu Signed-off-by: David S. Miller --- drivers/net/wwan/iosm/iosm_ipc_wwan.c | 42 +++++------------------------------ 1 file changed, 6 insertions(+), 36 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/wwan/iosm/iosm_ipc_wwan.c b/drivers/net/wwan/iosm/iosm_ipc_wwan.c index 0108d8d01ff2..4c9022a93e01 100644 --- a/drivers/net/wwan/iosm/iosm_ipc_wwan.c +++ b/drivers/net/wwan/iosm/iosm_ipc_wwan.c @@ -40,13 +40,11 @@ struct iosm_netdev_priv { * @ipc_imem: Pointer to imem data-struct * @sub_netlist: List of active netdevs * @dev: Pointer device structure - * @if_mutex: Mutex used for add and remove interface id */ struct iosm_wwan { struct iosm_imem *ipc_imem; struct iosm_netdev_priv __rcu *sub_netlist[IP_MUX_SESSION_END + 1]; struct device *dev; - struct mutex if_mutex; /* Mutex used for add and remove interface id */ }; /* Bring-up the wwan net link */ @@ -55,14 +53,11 @@ static int ipc_wwan_link_open(struct net_device *netdev) struct iosm_netdev_priv *priv = wwan_netdev_drvpriv(netdev); struct iosm_wwan *ipc_wwan = priv->ipc_wwan; int if_id = priv->if_id; - int ret; if (if_id < IP_MUX_SESSION_START || if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist)) return -EINVAL; - mutex_lock(&ipc_wwan->if_mutex); - /* get channel id */ priv->ch_id = ipc_imem_sys_wwan_open(ipc_wwan->ipc_imem, if_id); @@ -70,8 +65,7 @@ static int ipc_wwan_link_open(struct net_device *netdev) dev_err(ipc_wwan->dev, "cannot connect wwan0 & id %d to the IPC mem layer", if_id); - ret = -ENODEV; - goto out; + return -ENODEV; } /* enable tx path, DL data may follow */ @@ -80,10 +74,7 @@ static int ipc_wwan_link_open(struct net_device *netdev) dev_dbg(ipc_wwan->dev, "Channel id %d allocated to if_id %d", priv->ch_id, priv->if_id); - ret = 0; -out: - mutex_unlock(&ipc_wwan->if_mutex); - return ret; + return 0; } /* Bring-down the wwan net link */ @@ -93,11 +84,9 @@ static int ipc_wwan_link_stop(struct net_device *netdev) netif_stop_queue(netdev); - mutex_lock(&priv->ipc_wwan->if_mutex); ipc_imem_sys_wwan_close(priv->ipc_wwan->ipc_imem, priv->if_id, priv->ch_id); priv->ch_id = -1; - mutex_unlock(&priv->ipc_wwan->if_mutex); return 0; } @@ -190,26 +179,17 @@ static int ipc_wwan_newlink(void *ctxt, struct net_device *dev, priv->netdev = dev; priv->ipc_wwan = ipc_wwan; - mutex_lock(&ipc_wwan->if_mutex); - if (rcu_access_pointer(ipc_wwan->sub_netlist[if_id])) { - err = -EBUSY; - goto out_unlock; - } + if (rcu_access_pointer(ipc_wwan->sub_netlist[if_id])) + return -EBUSY; err = register_netdevice(dev); if (err) - goto out_unlock; + return err; rcu_assign_pointer(ipc_wwan->sub_netlist[if_id], priv); - mutex_unlock(&ipc_wwan->if_mutex); - netif_device_attach(dev); return 0; - -out_unlock: - mutex_unlock(&ipc_wwan->if_mutex); - return err; } static void ipc_wwan_dellink(void *ctxt, struct net_device *dev, @@ -223,17 +203,12 @@ static void ipc_wwan_dellink(void *ctxt, struct net_device *dev, if_id >= ARRAY_SIZE(ipc_wwan->sub_netlist))) return; - mutex_lock(&ipc_wwan->if_mutex); - if (WARN_ON(rcu_access_pointer(ipc_wwan->sub_netlist[if_id]) != priv)) - goto unlock; + return; RCU_INIT_POINTER(ipc_wwan->sub_netlist[if_id], NULL); /* unregistering includes synchronize_net() */ unregister_netdevice_queue(dev, head); - -unlock: - mutex_unlock(&ipc_wwan->if_mutex); } static const struct wwan_ops iosm_wwan_ops = { @@ -324,12 +299,9 @@ struct iosm_wwan *ipc_wwan_init(struct iosm_imem *ipc_imem, struct device *dev) ipc_wwan->dev = dev; ipc_wwan->ipc_imem = ipc_imem; - mutex_init(&ipc_wwan->if_mutex); - /* WWAN core will create a netdev for the default IP MUX channel */ if (wwan_register_ops(ipc_wwan->dev, &iosm_wwan_ops, ipc_wwan, IP_MUX_SESSION_DEFAULT)) { - mutex_destroy(&ipc_wwan->if_mutex); kfree(ipc_wwan); return NULL; } @@ -342,7 +314,5 @@ void ipc_wwan_deinit(struct iosm_wwan *ipc_wwan) /* This call will remove all child netdev(s) */ wwan_unregister_ops(ipc_wwan->dev); - mutex_destroy(&ipc_wwan->if_mutex); - kfree(ipc_wwan); } -- cgit v1.2.3-59-g8ed1b