[PATCH 3/5] net: devres: define a separate devres structure for devm_alloc_etherdev()

[Bartosz Golaszewski]

From: Bartosz Golaszewski <bgolaszew...@baylibre.com>

Not using a proxy structure to store struct net_device doesn't save
anything in terms of compiled code size or memory usage but significantly
decreases the readability of the code with all the pointer casting.

Define struct net_device_devres and use it in devm_alloc_etherdev_mqs().

Signed-off-by: Bartosz Golaszewski <bgolaszew...@baylibre.com>
---
 net/devres.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/net/devres.c b/net/devres.c
index c1465d9f9019..b97b0c5a8216 100644
--- a/net/devres.c
+++ b/net/devres.c
@@ -7,30 +7,34 @@
 #include <linux/etherdevice.h>
 #include <linux/netdevice.h>
 
-static void devm_free_netdev(struct device *dev, void *res)
+struct net_device_devres {
+       struct net_device *ndev;
+};
+
+static void devm_free_netdev(struct device *dev, void *this)
 {
-       free_netdev(*(struct net_device **)res);
+       struct net_device_devres *res = this;
+
+       free_netdev(res->ndev);
 }
 
 struct net_device *devm_alloc_etherdev_mqs(struct device *dev, int sizeof_priv,
                                           unsigned int txqs, unsigned int rxqs)
 {
-       struct net_device **dr;
-       struct net_device *netdev;
+       struct net_device_devres *dr;
 
        dr = devres_alloc(devm_free_netdev, sizeof(*dr), GFP_KERNEL);
        if (!dr)
                return NULL;
 
-       netdev = alloc_etherdev_mqs(sizeof_priv, txqs, rxqs);
-       if (!netdev) {
+       dr->ndev = alloc_etherdev_mqs(sizeof_priv, txqs, rxqs);
+       if (!dr->ndev) {
                devres_free(dr);
                return NULL;
        }
 
-       *dr = netdev;
        devres_add(dev, dr);
 
-       return netdev;
+       return dr->ndev;
 }
 EXPORT_SYMBOL(devm_alloc_etherdev_mqs);
-- 
2.25.0