Commit 67c24049 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

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: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 886e1387

drivers/net/dsa/ocelot/felix.c

+13 −0
Original line number Diff line number Diff line
@@ -522,6 +522,7 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports) 
	for (port = 0; port < num_phys_ports; port++) {

		struct ocelot_port *ocelot_port;

		struct regmap *target;

		u8 *template;



		ocelot_port = devm_kzalloc(ocelot->dev,

					   sizeof(struct ocelot_port),
@@ -547,10 +548,22 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports) 
			return PTR_ERR(target);

		}



		template = devm_kzalloc(ocelot->dev, OCELOT_TAG_LEN,

					GFP_KERNEL);

		if (!template) {

			dev_err(ocelot->dev,

				"Failed to allocate memory for DSA tag\n");

			kfree(port_phy_modes);

			return -ENOMEM;

		}



		ocelot_port->phy_mode = port_phy_modes[port];

		ocelot_port->ocelot = ocelot;

		ocelot_port->target = target;

		ocelot_port->xmit_template = template;

		ocelot->ports[port] = ocelot_port;



		felix->info->xmit_template_populate(ocelot, port);

	}



	kfree(port_phy_modes);

drivers/net/dsa/ocelot/felix.h

+1 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ struct felix_info { 
				 enum tc_setup_type type, void *type_data);

	void	(*port_sched_speed_set)(struct ocelot *ocelot, int port,

					u32 speed);

	void	(*xmit_template_populate)(struct ocelot *ocelot, int port);

};



extern struct felix_info		felix_info_vsc9959;

drivers/net/dsa/ocelot/felix_vsc9959.c

+20 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <soc/mscc/ocelot_ptp.h>

#include <soc/mscc/ocelot_sys.h>

#include <soc/mscc/ocelot.h>

#include <linux/packing.h>

#include <net/pkt_sched.h>

#include <linux/iopoll.h>

#include <linux/pci.h>
@@ -1432,6 +1433,24 @@ static int vsc9959_port_setup_tc(struct dsa_switch *ds, int port, 
	}

}



static void vsc9959_xmit_template_populate(struct ocelot *ocelot, int port)

{

	struct ocelot_port *ocelot_port = ocelot->ports[port];

	u8 *template = ocelot_port->xmit_template;

	u64 bypass, dest, src;



	/* Set the source port as the CPU port module and not the

	 * NPI port

	 */

	src = ocelot->num_phys_ports;

	dest = BIT(port);

	bypass = true;



	packing(template, &bypass, 127, 127, OCELOT_TAG_LEN, PACK, 0);

	packing(template, &dest,    68,  56, OCELOT_TAG_LEN, PACK, 0);

	packing(template, &src,     46,  43, OCELOT_TAG_LEN, PACK, 0);

}



struct felix_info felix_info_vsc9959 = {

	.target_io_res		= vsc9959_target_io_res,

	.port_io_res		= vsc9959_port_io_res,
@@ -1458,4 +1477,5 @@ struct felix_info felix_info_vsc9959 = { 
	.prevalidate_phy_mode	= vsc9959_prevalidate_phy_mode,

	.port_setup_tc          = vsc9959_port_setup_tc,

	.port_sched_speed_set   = vsc9959_sched_speed_set,

	.xmit_template_populate	= vsc9959_xmit_template_populate,

};

include/soc/mscc/ocelot.h

+2 −0
Original line number Diff line number Diff line
@@ -564,6 +564,8 @@ struct ocelot_port { 
	u8				ts_id;



	phy_interface_t			phy_mode;



	u8				*xmit_template;

};



struct ocelot {

net/dsa/tag_ocelot.c

+8 −13
Original line number Diff line number Diff line
@@ -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)) {