From 67c2404922c2c3f9cc0898aafaa4e3bea2bde084 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Mon, 13 Jul 2020 19:57:04 +0300 Subject: net: dsa: felix: create a template for the DSA tags on xmit With this patch we try to kill 2 birds with 1 stone. First of all, some switches that use tag_ocelot.c don't have the exact same bitfield layout for the DSA tags. The destination ports field is different for Seville VSC9953 for example. So the choices are to either duplicate tag_ocelot.c into a new tag_seville.c (sub-optimal) or somehow take into account a supposed ocelot->dest_ports_offset when packing this field into the DSA injection header (again not ideal). Secondly, tag_ocelot.c already needs to memset a 128-bit area to zero and call some packing() functions of dubious performance in the fastpath. And most of the values it needs to pack are pretty much constant (BYPASS=1, SRC_PORT=CPU, DEST=port index). So it would be good if we could improve that. The proposed solution is to allocate a memory area per port at probe time, initialize that with the statically defined bits as per chip hardware revision, and just perform a simpler memcpy in the fastpath. Other alternatives have been analyzed, such as: - Create a separate tag_seville.c: too much code duplication for just 1 bit field difference. - Create a separate DSA_TAG_PROTO_SEVILLE under tag_ocelot.c, just like tag_brcm.c, which would have a separate .xmit function. Again, too much code duplication for just 1 bit field difference. - Allocate the template from the init function of the tag_ocelot.c module, instead of from the driver: couldn't figure out a method of accessing the correct port template corresponding to the correct tagger in the .xmit function. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- net/dsa/tag_ocelot.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) (limited to 'net/dsa') diff --git a/net/dsa/tag_ocelot.c b/net/dsa/tag_ocelot.c index b0c98ee4e13b..42f327c06dca 100644 --- a/net/dsa/tag_ocelot.c +++ b/net/dsa/tag_ocelot.c @@ -137,11 +137,10 @@ static struct sk_buff *ocelot_xmit(struct sk_buff *skb, struct net_device *netdev) { struct dsa_port *dp = dsa_slave_to_port(netdev); - u64 bypass, dest, src, qos_class, rew_op; struct dsa_switch *ds = dp->ds; - int port = dp->index; struct ocelot *ocelot = ds->priv; - struct ocelot_port *ocelot_port = ocelot->ports[port]; + struct ocelot_port *ocelot_port; + u64 qos_class, rew_op; u8 *injection; if (unlikely(skb_cow_head(skb, OCELOT_TAG_LEN) < 0)) { @@ -149,19 +148,15 @@ static struct sk_buff *ocelot_xmit(struct sk_buff *skb, return NULL; } - injection = skb_push(skb, OCELOT_TAG_LEN); + ocelot_port = ocelot->ports[dp->index]; - memset(injection, 0, OCELOT_TAG_LEN); + injection = skb_push(skb, OCELOT_TAG_LEN); - /* Set the source port as the CPU port module and not the NPI port */ - src = ocelot->num_phys_ports; - dest = BIT(port); - bypass = true; + memcpy(injection, ocelot_port->xmit_template, OCELOT_TAG_LEN); + /* Fix up the fields which are not statically determined + * in the template + */ qos_class = skb->priority; - - packing(injection, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0); - packing(injection, &dest, 68, 56, OCELOT_TAG_LEN, PACK, 0); - packing(injection, &src, 46, 43, OCELOT_TAG_LEN, PACK, 0); packing(injection, &qos_class, 19, 17, OCELOT_TAG_LEN, PACK, 0); if (ocelot->ptp && (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) { -- cgit v1.2.3-59-g8ed1b