1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3   * This file contains all networking devres helpers.
4   */
5  
6  #include <linux/device.h>
7  #include <linux/etherdevice.h>
8  #include <linux/netdevice.h>
9  
10  struct net_device_devres {
11  	struct net_device *ndev;
12  };
13  
devm_free_netdev(struct device * dev,void * this)14  static void devm_free_netdev(struct device *dev, void *this)
15  {
16  	struct net_device_devres *res = this;
17  
18  	free_netdev(res->ndev);
19  }
20  
devm_alloc_etherdev_mqs(struct device * dev,int sizeof_priv,unsigned int txqs,unsigned int rxqs)21  struct net_device *devm_alloc_etherdev_mqs(struct device *dev, int sizeof_priv,
22  					   unsigned int txqs, unsigned int rxqs)
23  {
24  	struct net_device_devres *dr;
25  
26  	dr = devres_alloc(devm_free_netdev, sizeof(*dr), GFP_KERNEL);
27  	if (!dr)
28  		return NULL;
29  
30  	dr->ndev = alloc_etherdev_mqs(sizeof_priv, txqs, rxqs);
31  	if (!dr->ndev) {
32  		devres_free(dr);
33  		return NULL;
34  	}
35  
36  	devres_add(dev, dr);
37  
38  	return dr->ndev;
39  }
40  EXPORT_SYMBOL(devm_alloc_etherdev_mqs);
41  
devm_unregister_netdev(struct device * dev,void * this)42  static void devm_unregister_netdev(struct device *dev, void *this)
43  {
44  	struct net_device_devres *res = this;
45  
46  	unregister_netdev(res->ndev);
47  }
48  
netdev_devres_match(struct device * dev,void * this,void * match_data)49  static int netdev_devres_match(struct device *dev, void *this, void *match_data)
50  {
51  	struct net_device_devres *res = this;
52  	struct net_device *ndev = match_data;
53  
54  	return ndev == res->ndev;
55  }
56  
57  /**
58   *	devm_register_netdev - resource managed variant of register_netdev()
59   *	@dev: managing device for this netdev - usually the parent device
60   *	@ndev: device to register
61   *
62   *	This is a devres variant of register_netdev() for which the unregister
63   *	function will be called automatically when the managing device is
64   *	detached. Note: the net_device used must also be resource managed by
65   *	the same struct device.
66   */
devm_register_netdev(struct device * dev,struct net_device * ndev)67  int devm_register_netdev(struct device *dev, struct net_device *ndev)
68  {
69  	struct net_device_devres *dr;
70  	int ret;
71  
72  	/* struct net_device must itself be managed. For now a managed netdev
73  	 * can only be allocated by devm_alloc_etherdev_mqs() so the check is
74  	 * straightforward.
75  	 */
76  	if (WARN_ON(!devres_find(dev, devm_free_netdev,
77  				 netdev_devres_match, ndev)))
78  		return -EINVAL;
79  
80  	dr = devres_alloc(devm_unregister_netdev, sizeof(*dr), GFP_KERNEL);
81  	if (!dr)
82  		return -ENOMEM;
83  
84  	ret = register_netdev(ndev);
85  	if (ret) {
86  		devres_free(dr);
87  		return ret;
88  	}
89  
90  	dr->ndev = ndev;
91  	devres_add(ndev->dev.parent, dr);
92  
93  	return 0;
94  }
95  EXPORT_SYMBOL(devm_register_netdev);
96