can: dev: enable multi-queue for SocketCAN devices
The existing SocketCAN implementation provides alloc_candev() to
allocate a CAN device using a single Tx and Rx queue. This can lead to
priority inversion in case the single Tx queue is already full with low
priority messages and a high priority message needs to be sent while the
bus is fully loaded with medium priority messages.
This problem can be solved by using the existing multi-queue support of
the network subsytem. The commit makes it possible to use multi-queue in
the CAN subsystem in the same way it is used in the Ethernet subsystem
by adding an alloc_candev_mqs() call and accompanying macros. With this
support a CAN device can use multi-queue qdisc (e.g. mqprio) to avoid
the aforementioned priority inversion.
The exisiting functionality of alloc_candev() is the same as before.
CAN devices need to have prioritized multiple hardware queues or are
able to abort waiting for arbitration to make sensible use of
multi-queues.
Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com>
Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 5bb6e88..4916357 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -701,7 +701,8 @@ EXPORT_SYMBOL_GPL(alloc_can_err_skb);
/*
* Allocate and setup space for the CAN network device
*/
-struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
+struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
+ unsigned int txqs, unsigned int rxqs)
{
struct net_device *dev;
struct can_priv *priv;
@@ -713,7 +714,8 @@ struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
else
size = sizeof_priv;
- dev = alloc_netdev(size, "can%d", NET_NAME_UNKNOWN, can_setup);
+ dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
+ txqs, rxqs);
if (!dev)
return NULL;
@@ -732,7 +734,7 @@ struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max)
return dev;
}
-EXPORT_SYMBOL_GPL(alloc_candev);
+EXPORT_SYMBOL_GPL(alloc_candev_mqs);
/*
* Free space of the CAN network device