[RFC,3/4] wwan: add interface creation support

Message ID	20210601100320.7d39e9c33a18.I0474861dad426152ac7e7afddfd7fe3ce70870e4@changeid
State	New
Headers	show Return-Path: <netdev-owner@kernel.org> From: Johannes Berg <johannes@sipsolutions.net> To: linux-wireless@vger.kernel.org, netdev@vger.kernel.org Cc: m.chetan.kumar@intel.com, loic.poulain@linaro.org, Johannes Berg <johannes.berg@intel.com> Subject: [RFC 3/4] wwan: add interface creation support Date: Tue, 1 Jun 2021 10:05:37 +0200 Message-Id: <20210601100320.7d39e9c33a18.I0474861dad426152ac7e7afddfd7fe3ce70870e4@changeid> In-Reply-To: <20210601080538.71036-1-johannes@sipsolutions.net> References: <20210601080538.71036-1-johannes@sipsolutions.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	wwan framework netdev creation \| expand [RFC,0/4] wwan framework netdev creation [RFC,1/4] iosm: fix stats and RCU bugs in RX [RFC,2/4] rtnetlink: add alloc() method to rtnl_link_ops [RFC,3/4] wwan: add interface creation support [RFC,4/4] iosm: convert to generic wwan ops

diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c index cff04e532c1e..b1ad78f386bc 100644 --- a/drivers/net/wwan/wwan_core.c +++ b/drivers/net/wwan/wwan_core.c @@ -13,6 +13,8 @@ #include <linux/slab.h> #include <linux/types.h> #include <linux/wwan.h> +#include <net/rtnetlink.h> +#include <uapi/linux/wwan.h> #define WWAN_MAX_MINORS 256 /* 256 minors allowed with register_chrdev() */ @@ -524,24 +526,231 @@ static const struct file_operations wwan_port_fops = { .llseek = noop_llseek, }; +struct wwan_dev_reg { + struct list_head list; + struct device *dev; + const struct wwan_ops *ops; + void *ctxt; +}; + +static DEFINE_MUTEX(wwan_mtx); +static LIST_HEAD(wwan_devs); + +int wwan_register_ops(struct device *parent, const struct wwan_ops *ops, + void *ctxt) +{ + struct wwan_dev_reg *reg; + int ret; + + if (WARN_ON(!parent || !ops)) + return -EINVAL; + + mutex_lock(&wwan_mtx); + list_for_each_entry(reg, &wwan_devs, list) { + if (WARN_ON(reg->dev == parent)) { + ret = -EBUSY; + goto out; + } + } + + reg = kzalloc(sizeof(*reg), GFP_KERNEL); + if (!reg) { + ret = -ENOMEM; + goto out; + } + + reg->dev = parent; + reg->ops = ops; + reg->ctxt = ctxt; + list_add_tail(&reg->list, &wwan_devs); + + ret = 0; + +out: + mutex_unlock(&wwan_mtx); + return ret; +} +EXPORT_SYMBOL_GPL(wwan_register_ops); + +void wwan_unregister_ops(struct device *parent) +{ + struct wwan_dev_reg *tmp; + + mutex_lock(&wwan_mtx); + list_for_each_entry(tmp, &wwan_devs, list) { + if (tmp->dev == parent) { + list_del(&tmp->list); + break; + } + } + mutex_unlock(&wwan_mtx); +} +EXPORT_SYMBOL_GPL(wwan_unregister_ops); + +static struct wwan_dev_reg *wwan_find_by_name(const char *name) +{ + struct wwan_dev_reg *tmp; + + lockdep_assert_held(&wwan_mtx); + + list_for_each_entry(tmp, &wwan_devs, list) { + if (strcmp(name, dev_name(tmp->dev)) == 0) + return tmp; + } + + return NULL; +} + +static struct wwan_dev_reg *wwan_find_by_dev(struct device *dev) +{ + struct wwan_dev_reg *tmp; + + lockdep_assert_held(&wwan_mtx); + + list_for_each_entry(tmp, &wwan_devs, list) { + if (tmp->dev == dev) + return tmp; + } + + return NULL; +} + +static int wwan_rtnl_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + if (!data) + return -EINVAL; + + if (!data[IFLA_WWAN_LINK_ID] || !data[IFLA_WWAN_DEV_NAME]) + return -EINVAL; + + return 0; +} + +static struct device_type wwan_type = { .name = "wwan" }; + +static struct net_device *wwan_rtnl_alloc(struct nlattr *tb[], + struct nlattr *data[], + const char *ifname, + unsigned char name_assign_type, + unsigned int num_tx_queues, + unsigned int num_rx_queues) +{ + const char *devname = nla_data(data[IFLA_WWAN_DEV_NAME]); + struct wwan_dev_reg *reg; + struct net_device *dev; + + mutex_lock(&wwan_mtx); + reg = wwan_find_by_name(devname); + if (!reg) { + mutex_unlock(&wwan_mtx); + return ERR_PTR(-EINVAL); + } + + dev = alloc_netdev_mqs(reg->ops->priv_size, ifname, name_assign_type, + reg->ops->setup, num_tx_queues, num_rx_queues); + + mutex_unlock(&wwan_mtx); + + if (dev) { + SET_NETDEV_DEV(dev, reg->dev); + SET_NETDEV_DEVTYPE(dev, &wwan_type); + } + + return dev; +} + +static int wwan_rtnl_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct wwan_dev_reg *reg; + u32 link_id = nla_get_u32(data[IFLA_WWAN_LINK_ID]); + int ret; + + mutex_lock(&wwan_mtx); + reg = wwan_find_by_dev(dev->dev.parent); + if (!reg) { + mutex_unlock(&wwan_mtx); + return -EINVAL; + } + + if (reg->ops->newlink) + ret = reg->ops->newlink(reg->ctxt, dev, link_id, extack); + else + ret = register_netdevice(dev); + + mutex_unlock(&wwan_mtx); + + return ret; +} + +static void wwan_rtnl_dellink(struct net_device *dev, struct list_head *head) +{ + struct wwan_dev_reg *reg; + + mutex_lock(&wwan_mtx); + reg = wwan_find_by_dev(dev->dev.parent); + if (!reg) { + mutex_unlock(&wwan_mtx); + return; + } + + if (reg->ops->dellink) + reg->ops->dellink(reg->ctxt, dev, head); + else + unregister_netdevice(dev); + + mutex_unlock(&wwan_mtx); +} + +static const struct nla_policy wwan_rtnl_policy[IFLA_WWAN_MAX + 1] = { + [IFLA_WWAN_DEV_NAME] = { .type = NLA_NUL_STRING }, + [IFLA_WWAN_LINK_ID] = { .type = NLA_U32 }, +}; + +static struct rtnl_link_ops wwan_rtnl_link_ops __read_mostly = { + .kind = "wwan", + .maxtype = __IFLA_WWAN_MAX, + .alloc = wwan_rtnl_alloc, + .validate = wwan_rtnl_validate, + .newlink = wwan_rtnl_newlink, + .dellink = wwan_rtnl_dellink, + .policy = wwan_rtnl_policy, +}; + static int __init wwan_init(void) { + int err; + + err = rtnl_link_register(&wwan_rtnl_link_ops); + if (err) + return err; + wwan_class = class_create(THIS_MODULE, "wwan"); - if (IS_ERR(wwan_class)) - return PTR_ERR(wwan_class); + if (IS_ERR(wwan_class)) { + err = PTR_ERR(wwan_class); + goto unregister; + } /* chrdev used for wwan ports */ wwan_major = register_chrdev(0, "wwan_port", &wwan_port_fops); if (wwan_major < 0) { - class_destroy(wwan_class); - return wwan_major; + err = wwan_major; + goto destroy; } - return 0; + err = 0; +destroy: + class_destroy(wwan_class); +unregister: + rtnl_link_unregister(&wwan_rtnl_link_ops); + return err; } static void __exit wwan_exit(void) { + rtnl_link_unregister(&wwan_rtnl_link_ops); unregister_chrdev(wwan_major, "wwan_port"); class_destroy(wwan_class); } diff --git a/include/linux/wwan.h b/include/linux/wwan.h index aa05a253dcf9..d07301962ff7 100644 --- a/include/linux/wwan.h +++ b/include/linux/wwan.h @@ -7,6 +7,7 @@ #include <linux/device.h> #include <linux/kernel.h> #include <linux/skbuff.h> +#include <linux/netlink.h> /** * enum wwan_port_type - WWAN port types @@ -108,4 +109,39 @@ void wwan_port_txon(struct wwan_port *port); */ void *wwan_port_get_drvdata(struct wwan_port *port); +/** + * struct wwan_ops - WWAN device ops + * @priv_size: size of private netdev data area + * @setup: set up a new netdev + * @newlink: register the new netdev + * @dellink: remove the given netdev + */ +struct wwan_ops { + unsigned int priv_size; + void (*setup)(struct net_device *dev); + int (*newlink)(void *ctxt, struct net_device *dev, + u32 if_id, struct netlink_ext_ack *extack); + void (*dellink)(void *ctxt, struct net_device *dev, + struct list_head *head); +}; + +/** + * wwan_register_ops - register WWAN device ops + * @parent: Device to use as parent and shared by all WWAN ports and + * created netdevs + * @ops: operations to register + * @ctxt: context to pass to operations + * + * Returns: 0 on success, a negative error code on failure + */ +int wwan_register_ops(struct device *parent, const struct wwan_ops *ops, + void *ctxt); + +/** + * wwan_unregister_ops - remove WWAN device ops + * @parent: Device to use as parent and shared by all WWAN ports and + * created netdevs + */ +void wwan_unregister_ops(struct device *parent); + #endif /* __WWAN_H */ diff --git a/include/uapi/linux/wwan.h b/include/uapi/linux/wwan.h new file mode 100644 index 000000000000..a134c823cfbd --- /dev/null +++ b/include/uapi/linux/wwan.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ +/* + * Copyright (C) 2021 Intel Corporation. + */ +#ifndef _UAPI_WWAN_H_ +#define _UAPI_WWAN_H_ + +enum { + IFLA_WWAN_UNSPEC, + IFLA_WWAN_DEV_NAME, /* nul-string */ + IFLA_WWAN_LINK_ID, /* u32 */ + + __IFLA_WWAN_MAX +}; +#define IFLA_WWAN_MAX (__IFLA_WWAN_MAX - 1) + +#endif /* _UAPI_WWAN_H_ */

[RFC,3/4] wwan: add interface creation support

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