can: introduce CAN midlayer private and allocate it automatically

This patch introduces the CAN midlayer private structure ("struct
can_ml_priv") which should be used to hold protocol specific per device
data structures. For now it's only member is "struct can_dev_rcv_lists".

The CAN midlayer private is allocated via alloc_netdev()'s private and
assigned to "struct net_device::ml_priv" during device creation. This is
done transparently for CAN drivers using alloc_candev(). The slcan, vcan
and vxcan drivers which are not using alloc_candev() have been adopted
manually. The memory layout of the netdev_priv allocated via
alloc_candev() will looke like this:

  +-------------------------+
  | driver's priv           |
  +-------------------------+
  | struct can_ml_priv      |
  +-------------------------+
  | array of struct sk_buff |
  +-------------------------+

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index aa97dbc797b6..5b2e95425e69 100644
--- a/drivers/net/can/slcan.c
+++ b/drivers/net/can/slcan.c
@@ -55,6 +55,7 @@
 #include <linux/workqueue.h>
 #include <linux/can.h>
 #include <linux/can/skb.h>
+#include <linux/can/can-ml.h>
 
 MODULE_ALIAS_LDISC(N_SLCAN);
 MODULE_DESCRIPTION("serial line CAN interface");
@@ -514,6 +515,7 @@ static struct slcan *slc_alloc(void)
 	char name[IFNAMSIZ];
 	struct net_device *dev = NULL;
 	struct slcan       *sl;
+	int size;
 
 	for (i = 0; i < maxdev; i++) {
 		dev = slcan_devs[i];
@@ -527,7 +529,8 @@ static struct slcan *slc_alloc(void)
 		return NULL;
 
 	sprintf(name, "slcan%d", i);
-	dev = alloc_netdev(sizeof(*sl), name, NET_NAME_UNKNOWN, slc_setup);
+	size = ALIGN(sizeof(*sl), NETDEV_ALIGN) + sizeof(struct can_ml_priv);
+	dev = alloc_netdev(size, name, NET_NAME_UNKNOWN, slc_setup);
 	if (!dev)
 		return NULL;