net/devres.c

   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
  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
  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
  42 static void devm_netdev_release(struct device *dev, void *this)
  43 {
  44         struct net_device_devres *res = this;
  45
  46         unregister_netdev(res->ndev);
  47 }
  48
  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  */
  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_netdev_release, 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);