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 call 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