net: Add init_dummy_netdev() and fix EMAC driver using it

[net-next-2.6.git] / net / core / dev.c

diff --git a/net/core/dev.c b/net/core/dev.c
index 60377b6c0a804798a41ce8d128421a41226c25f1..8d675975d85b97cd6352e56999d6f3a1c13d4b0b 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4430,6 +4430,45 @@ err_uninit:
        goto out;
 }
 
+/**
+ *     init_dummy_netdev       - init a dummy network device for NAPI
+ *     @dev: device to init
+ *
+ *     This takes a network device structure and initialize the minimum
+ *     amount of fields so it can be used to schedule NAPI polls without
+ *     registering a full blown interface. This is to be used by drivers
+ *     that need to tie several hardware interfaces to a single NAPI
+ *     poll scheduler due to HW limitations.
+ */
+int init_dummy_netdev(struct net_device *dev)
+{
+       /* Clear everything. Note we don't initialize spinlocks
+        * are they aren't supposed to be taken by any of the
+        * NAPI code and this dummy netdev is supposed to be
+        * only ever used for NAPI polls
+        */
+       memset(dev, 0, sizeof(struct net_device));
+
+       /* make sure we BUG if trying to hit standard
+        * register/unregister code path
+        */
+       dev->reg_state = NETREG_DUMMY;
+
+       /* initialize the ref count */
+       atomic_set(&dev->refcnt, 1);
+
+       /* NAPI wants this */
+       INIT_LIST_HEAD(&dev->napi_list);
+
+       /* a dummy interface is started by default */
+       set_bit(__LINK_STATE_PRESENT, &dev->state);
+       set_bit(__LINK_STATE_START, &dev->state);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(init_dummy_netdev);
+
+
 /**
  *     register_netdev - register a network device
  *     @dev: device to register