can: make use of preallocated can_ml_priv for per device struct can_dev_rcv_lists
This patch removes the old method of allocating the per device protocol
specific memory via a netdevice_notifier. This had the drawback, that
the allocation can fail, leading to a lot of null pointer checks in the
code. This also makes the live cycle management of this memory quite
complicated.
This patch switches from the allocating the struct can_dev_rcv_lists in
a NETDEV_REGISTER call to using the dev->ml_priv, which is allocated by
the driver since the previous patch.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 723299d..6ed85e2 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -302,10 +302,12 @@ EXPORT_SYMBOL(can_send);
static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net,
struct net_device *dev)
{
- if (!dev)
+ if (dev) {
+ struct can_ml_priv *ml_priv = dev->ml_priv;
+ return &ml_priv->dev_rcv_lists;
+ } else {
return net->can.rx_alldev_list;
- else
- return (struct can_dev_rcv_lists *)dev->ml_priv;
+ }
}
/**
@@ -561,12 +563,6 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
if (rcv_lists_stats->rcv_entries > 0)
rcv_lists_stats->rcv_entries--;
- /* remove device structure requested by NETDEV_UNREGISTER */
- if (dev_rcv_lists->remove_on_zero_entries && !dev_rcv_lists->entries) {
- kfree(dev_rcv_lists);
- dev->ml_priv = NULL;
- }
-
out:
spin_unlock(&net->can.rcvlists_lock);
@@ -788,41 +784,14 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- struct can_dev_rcv_lists *dev_rcv_lists;
if (dev->type != ARPHRD_CAN)
return NOTIFY_DONE;
switch (msg) {
case NETDEV_REGISTER:
-
- /* create new dev_rcv_lists for this device */
- dev_rcv_lists = kzalloc(sizeof(*dev_rcv_lists), GFP_KERNEL);
- if (!dev_rcv_lists)
- return NOTIFY_DONE;
- BUG_ON(dev->ml_priv);
- dev->ml_priv = dev_rcv_lists;
-
- break;
-
- case NETDEV_UNREGISTER:
- spin_lock(&dev_net(dev)->can.rcvlists_lock);
-
- dev_rcv_lists = dev->ml_priv;
- if (dev_rcv_lists) {
- if (dev_rcv_lists->entries)
- dev_rcv_lists->remove_on_zero_entries = 1;
- else {
- kfree(dev_rcv_lists);
- dev->ml_priv = NULL;
- }
- } else {
- pr_err("can: notifier: receive list not found for dev %s\n",
- dev->name);
- }
-
- spin_unlock(&dev_net(dev)->can.rcvlists_lock);
-
+ WARN(!dev->ml_priv,
+ "No CAN mid layer private allocated, please fix your driver and use alloc_candev()!\n");
break;
}