[PATCH net-next] net: dsa: tag_ocelot: use traffic class to map priority on injected header

For Ocelot switches, the CPU injected frames have an injection header
where it can specify the QoS class of the packet and the DSA tag, now it
uses the SKB priority to set that. If a traffic class to priority
mapping is configured on the netdevice (with mqprio for example ...), it
won't be considered for CPU injected headers. This patch make the QoS
class aligned to the priority to traffic class mapping if it exists.

Signed-off-by: Xiaoliang Yang <redacted>
Signed-off-by: Marouen Ghodhbane <redacted>
---
 net/dsa/tag_ocelot.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/dsa/tag_ocelot.c b/net/dsa/tag_ocelot.c
index 4ba460c5a880..0d81f172b7a6 100644
--- a/net/dsa/tag_ocelot.c
+++ b/net/dsa/tag_ocelot.c

@@ -47,9 +47,13 @@ static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
 	void *injection;
 	__be32 *prefix;
 	u32 rew_op = 0;
+	u64 qos_class;
 
 	ocelot_xmit_get_vlan_info(skb, dp, &vlan_tci, &tag_type);
 
+	qos_class = netdev_get_num_tc(netdev) ?
+		    netdev_get_prio_tc_map(netdev, skb->priority) : skb->priority;
+
 	injection = skb_push(skb, OCELOT_TAG_LEN);
 	prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);
 

@@ -57,7 +61,7 @@ static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
 	memset(injection, 0, OCELOT_TAG_LEN);
 	ocelot_ifh_set_bypass(injection, 1);
 	ocelot_ifh_set_src(injection, ds->num_ports);
-	ocelot_ifh_set_qos_class(injection, skb->priority);
+	ocelot_ifh_set_qos_class(injection, qos_class);
 	ocelot_ifh_set_vlan_tci(injection, vlan_tci);
 	ocelot_ifh_set_tag_type(injection, tag_type);
 

-- 
2.17.1

On Tue, 21 Dec 2021 19:02:09 +0800 Xiaoliang Yang wrote:

For Ocelot switches, the CPU injected frames have an injection header
where it can specify the QoS class of the packet and the DSA tag, now it
uses the SKB priority to set that. If a traffic class to priority
mapping is configured on the netdevice (with mqprio for example ...), it
won't be considered for CPU injected headers. This patch make the QoS
class aligned to the priority to traffic class mapping if it exists.

Signed-off-by: Xiaoliang Yang <redacted>
Signed-off-by: Marouen Ghodhbane <redacted>

Is this a fix? Looks like one.

On Wed, 23 Dec 2021 06:24 Jakub Kicinski wrote:

quoted

For Ocelot switches, the CPU injected frames have an injection header
where it can specify the QoS class of the packet and the DSA tag, now
it uses the SKB priority to set that. If a traffic class to priority
mapping is configured on the netdevice (with mqprio for example ...),
it won't be considered for CPU injected headers. This patch make the
QoS class aligned to the priority to traffic class mapping if it exists.

Signed-off-by: Xiaoliang Yang <redacted>
Signed-off-by: Marouen Ghodhbane <redacted>

Is this a fix? Looks like one.

Yes, It can be seen as a fix, I will add fix tag and resend to net, thanks.