Commit 47d75f78 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net: dsa: report and change port dscp priority using dcbnl 



Similar to the port-based default priority, IEEE 802.1Q-2018 allows the
Application Priority Table to define QoS classes (0 to 7) per IP DSCP
value (0 to 63).

In the absence of an app table entry for a packet with DSCP value X,
QoS classification for that packet falls back to other methods (VLAN PCP
or port-based default). The presence of an app table for DSCP value X
with priority Y makes the hardware classify the packet to QoS class Y.

As opposed to the default-prio where DSA exposes only a "set" in
dsa_switch_ops (because the port-based default is the fallback, it
always exists, either implicitly or explicitly), for DSCP priorities we
expose an "add" and a "del". The addition of a DSCP entry means trusting
that DSCP priority, the deletion means ignoring it.

Drivers that already trust (at least some) DSCP values can describe
their configuration in dsa_switch_ops :: port_get_dscp_prio(), which is
called for each DSCP value from 0 to 63.

Again, there can be more than one dcbnl app table entry for the same
DSCP value, DSA chooses the one with the largest configured priority.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d538eca8

include/net/dsa.h

+5 −0
Original line number Diff line number Diff line
@@ -898,6 +898,11 @@ struct dsa_switch_ops { 
	int	(*port_get_default_prio)(struct dsa_switch *ds, int port);

	int	(*port_set_default_prio)(struct dsa_switch *ds, int port,

					 u8 prio);

	int	(*port_get_dscp_prio)(struct dsa_switch *ds, int port, u8 dscp);

	int	(*port_add_dscp_prio)(struct dsa_switch *ds, int port, u8 dscp,

				      u8 prio);

	int	(*port_del_dscp_prio)(struct dsa_switch *ds, int port, u8 dscp,

				      u8 prio);



	/*

	 * Suspend and resume

net/dsa/slave.c

+86 −0
Original line number Diff line number Diff line
@@ -1880,6 +1880,40 @@ dsa_slave_dcbnl_set_default_prio(struct net_device *dev, struct dcb_app *app) 
	return 0;

}



static int __maybe_unused

dsa_slave_dcbnl_add_dscp_prio(struct net_device *dev, struct dcb_app *app)

{

	struct dsa_port *dp = dsa_slave_to_port(dev);

	struct dsa_switch *ds = dp->ds;

	unsigned long mask, new_prio;

	int err, port = dp->index;

	u8 dscp = app->protocol;



	if (!ds->ops->port_add_dscp_prio)

		return -EOPNOTSUPP;



	if (dscp >= 64) {

		netdev_err(dev, "DSCP APP entry with protocol value %u is invalid\n",

			   dscp);

		return -EINVAL;

	}



	err = dcb_ieee_setapp(dev, app);

	if (err)

		return err;



	mask = dcb_ieee_getapp_mask(dev, app);

	new_prio = __fls(mask);



	err = ds->ops->port_add_dscp_prio(ds, port, dscp, new_prio);

	if (err) {

		dcb_ieee_delapp(dev, app);

		return err;

	}



	return 0;

}



static int __maybe_unused dsa_slave_dcbnl_ieee_setapp(struct net_device *dev,

						      struct dcb_app *app)

{
@@ -1892,6 +1926,8 @@ static int __maybe_unused dsa_slave_dcbnl_ieee_setapp(struct net_device *dev, 
			return -EOPNOTSUPP;

		}

		break;

	case IEEE_8021QAZ_APP_SEL_DSCP:

		return dsa_slave_dcbnl_add_dscp_prio(dev, app);

	default:

		return -EOPNOTSUPP;

	}
@@ -1924,6 +1960,30 @@ dsa_slave_dcbnl_del_default_prio(struct net_device *dev, struct dcb_app *app) 
	return 0;

}



static int __maybe_unused

dsa_slave_dcbnl_del_dscp_prio(struct net_device *dev, struct dcb_app *app)

{

	struct dsa_port *dp = dsa_slave_to_port(dev);

	struct dsa_switch *ds = dp->ds;

	int err, port = dp->index;

	u8 dscp = app->protocol;



	if (!ds->ops->port_del_dscp_prio)

		return -EOPNOTSUPP;



	err = dcb_ieee_delapp(dev, app);

	if (err)

		return err;



	err = ds->ops->port_del_dscp_prio(ds, port, dscp, app->priority);

	if (err) {

		dcb_ieee_setapp(dev, app);

		return err;

	}



	return 0;

}



static int __maybe_unused dsa_slave_dcbnl_ieee_delapp(struct net_device *dev,

						      struct dcb_app *app)

{
@@ -1936,6 +1996,8 @@ static int __maybe_unused dsa_slave_dcbnl_ieee_delapp(struct net_device *dev, 
			return -EOPNOTSUPP;

		}

		break;

	case IEEE_8021QAZ_APP_SEL_DSCP:

		return dsa_slave_dcbnl_del_dscp_prio(dev, app);

	default:

		return -EOPNOTSUPP;

	}
@@ -1967,6 +2029,30 @@ static int dsa_slave_dcbnl_init(struct net_device *dev) 
			return err;

	}



	if (ds->ops->port_get_dscp_prio) {

		int protocol;



		for (protocol = 0; protocol < 64; protocol++) {

			struct dcb_app app = {

				.selector = IEEE_8021QAZ_APP_SEL_DSCP,

				.protocol = protocol,

			};

			int prio;



			prio = ds->ops->port_get_dscp_prio(ds, port, protocol);

			if (prio == -EOPNOTSUPP)

				continue;

			if (prio < 0)

				return prio;



			app.priority = prio;



			err = dcb_ieee_setapp(dev, &app);

			if (err)

				return err;

		}

	}



	return 0;

}