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
10struct net_device_devres {
11	struct net_device *ndev;
12};
13
14static 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
21struct 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}
40EXPORT_SYMBOL(devm_alloc_etherdev_mqs);
41
42static 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
49static 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 */
67int 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}
95EXPORT_SYMBOL(devm_register_netdev);
96