[NET]: Dynamically allocate the loopback device, part 2.

Doing this makes loopback.c a better example of how to do a
simple network device, and it removes the special case
single static allocation of a struct net_device, hopefully
making maintenance easier.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-By: Kirill Korotaev <dev@sw.ru>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>

1 files changed, 44 insertions, 28 deletions

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 588092e13186..4b6f7b2abea5 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -202,44 +202,60 @@ static const struct ethtool_ops loopback_ethtool_ops = {
  * The loopback device is special. There is only one instance and
  * it is statically allocated. Don't do this for other devices.
  */
-struct net_device __loopback_dev = {
-        .name                   = "lo",
-        .get_stats              = &get_stats,
-        .mtu                    = (16 * 1024) + 20 + 20 + 12,
-        .hard_start_xmit        = loopback_xmit,
-        .hard_header            = eth_header,
-        .hard_header_cache      = eth_header_cache,
-        .header_cache_update    = eth_header_cache_update,
-        .hard_header_len        = ETH_HLEN,     /* 14   */
-        .addr_len               = ETH_ALEN,     /* 6    */
-        .tx_queue_len           = 0,
-        .type                   = ARPHRD_LOOPBACK,      /* 0x0001*/
-        .rebuild_header         = eth_rebuild_header,
-        .flags                  = IFF_LOOPBACK,
-        .features               = NETIF_F_SG | NETIF_F_FRAGLIST
+static void loopback_setup(struct net_device *dev)
+{
+        dev->get_stats          = &get_stats;
+        dev->mtu                = (16 * 1024) + 20 + 20 + 12;
+        dev->hard_start_xmit    = loopback_xmit;
+        dev->hard_header        = eth_header;
+        dev->hard_header_cache  = eth_header_cache;
+        dev->header_cache_update = eth_header_cache_update;
+        dev->hard_header_len    = ETH_HLEN;     /* 14   */
+        dev->addr_len           = ETH_ALEN;     /* 6    */
+        dev->tx_queue_len       = 0;
+        dev->type               = ARPHRD_LOOPBACK;      /* 0x0001*/
+        dev->rebuild_header     = eth_rebuild_header;
+        dev->flags              = IFF_LOOPBACK;
+        dev->features           = NETIF_F_SG | NETIF_F_FRAGLIST
 #ifdef LOOPBACK_TSO
-                                  | NETIF_F_TSO
+                | NETIF_F_TSO
 #endif
-                                  | NETIF_F_NO_CSUM | NETIF_F_HIGHDMA
-                                  | NETIF_F_LLTX
-                                  | NETIF_F_NETNS_LOCAL,
-        .ethtool_ops            = &loopback_ethtool_ops,
-        .nd_net                 = &init_net,
-};
-
-struct net_device *loopback_dev = &__loopback_dev;
+                | NETIF_F_NO_CSUM
+                | NETIF_F_HIGHDMA
+                | NETIF_F_LLTX
+                | NETIF_F_NETNS_LOCAL,
+        dev->ethtool_ops        = &loopback_ethtool_ops;
+}
 
 /* Setup and register the loopback device. */
 static int __init loopback_init(void)
 {
-        int err = register_netdev(loopback_dev);
+        struct net_device *dev;
+        int err;
+
+        err = -ENOMEM;
+        dev = alloc_netdev(0, "lo", loopback_setup);
+        if (!dev)
+                goto out;
 
+        err = register_netdev(dev);
         if (err)
-                panic("loopback: Failed to register netdevice: %d\n", err);
+                goto out_free_netdev;
 
+        err = 0;
+        loopback_dev = dev;
+
+out:
+        if (err)
+                panic("loopback: Failed to register netdevice: %d\n", err);
         return err;
-};
 
-module_init(loopback_init);
+out_free_netdev:
+        free_netdev(dev);
+        goto out;
+}
+
+fs_initcall(loopback_init);
 
+struct net_device *loopback_dev;
 EXPORT_SYMBOL(loopback_dev);