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authorZhu Yi <yi.zhu5@cn.bosch.com>2018-06-13 17:37:17 +0300
committerMarc Kleine-Budde <mkl@pengutronix.de>2018-07-27 11:40:16 +0300
commit038709071328ff68a936c6b8c33a24a805eea3c5 (patch)
tree2ce62a90ee995c7355f6a6e045d90507fac089d5 /include/linux/can
parent8551e71d1063edfaab03585e5f78077ec1c85da3 (diff)
downloadlinux-038709071328ff68a936c6b8c33a24a805eea3c5.tar.xz
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>
Diffstat (limited to 'include/linux/can')
-rw-r--r--include/linux/can/dev.h7
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 055aaf5ed9af..a83e1f632eb7 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -143,7 +143,12 @@ u8 can_dlc2len(u8 can_dlc);
/* map the sanitized data length to an appropriate data length code */
u8 can_len2dlc(u8 len);
-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);
+#define alloc_candev(sizeof_priv, echo_skb_max) \
+ alloc_candev_mqs(sizeof_priv, echo_skb_max, 1, 1)
+#define alloc_candev_mq(sizeof_priv, echo_skb_max, count) \
+ alloc_candev_mqs(sizeof_priv, echo_skb_max, count, count)
void free_candev(struct net_device *dev);
/* a candev safe wrapper around netdev_priv */