Commit c570f861 authored by Oleksij Rempel's avatar Oleksij Rempel Committed by David S. Miller
Browse files

net: dsa: microchip: add ETS Qdisc support for KSZ9477 series 

Add ETS Qdisc support for KSZ9477 of switches. Current implementation is
limited to strict priority mode.

Tested on KSZ8563R with following configuration:
tc qdisc replace dev lan2 root handle 1: ets strict 4 \
  priomap 3 3 2 2 1 1 0 0
ip link add link lan2 name v1 type vlan id 1 \
  egress-qos-map 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7

and patched iperf3 version:
https://github.com/esnet/iperf/pull/1476


iperf3 -c 172.17.0.1 -b100M  -l1472 -t100 -u -R --sock-prio 2

Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Acked-by: default avatarArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 69444581

drivers/net/dsa/microchip/ksz_common.c

+218 −0
Original line number Diff line number Diff line
@@ -1085,6 +1085,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 3,

		.num_tx_queues = 4,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &ksz9477_dev_ops,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
@@ -1224,6 +1225,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 4,

		.num_tx_queues = 4,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &ksz9477_dev_ops,

		.phy_errata_9477 = true,

		.mib_names = ksz9477_mib_names,
@@ -1348,6 +1350,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 3,

		.num_tx_queues = 4,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &ksz9477_dev_ops,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
@@ -1375,6 +1378,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 3,

		.num_tx_queues = 4,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &ksz9477_dev_ops,

		.phy_errata_9477 = true,

		.mib_names = ksz9477_mib_names,
@@ -1407,6 +1411,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 6,

		.num_tx_queues = 8,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &lan937x_dev_ops,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
@@ -1433,6 +1438,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 6,

		.num_tx_queues = 8,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &lan937x_dev_ops,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
@@ -1459,6 +1465,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 6,

		.num_tx_queues = 8,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &lan937x_dev_ops,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
@@ -1489,6 +1496,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 6,

		.num_tx_queues = 8,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &lan937x_dev_ops,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
@@ -1519,6 +1527,7 @@ const struct ksz_chip_data ksz_switch_chips[] = { 
		.port_nirqs = 6,

		.num_tx_queues = 8,

		.tc_cbs_supported = true,

		.tc_ets_supported = true,

		.ops = &lan937x_dev_ops,

		.mib_names = ksz9477_mib_names,

		.mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
@@ -3144,12 +3153,221 @@ static int ksz_setup_tc_cbs(struct dsa_switch *ds, int port, 
				 MTI_SHAPING_SRP);

}



static int ksz_disable_egress_rate_limit(struct ksz_device *dev, int port)

{

	int queue, ret;



	/* Configuration will not take effect until the last Port Queue X

	 * Egress Limit Control Register is written.

	 */

	for (queue = 0; queue < dev->info->num_tx_queues; queue++) {

		ret = ksz_pwrite8(dev, port, KSZ9477_REG_PORT_OUT_RATE_0 + queue,

				  KSZ9477_OUT_RATE_NO_LIMIT);

		if (ret)

			return ret;

	}



	return 0;

}



static int ksz_ets_band_to_queue(struct tc_ets_qopt_offload_replace_params *p,

				 int band)

{

	/* Compared to queues, bands prioritize packets differently. In strict

	 * priority mode, the lowest priority is assigned to Queue 0 while the

	 * highest priority is given to Band 0.

	 */

	return p->bands - 1 - band;

}



static int ksz_queue_set_strict(struct ksz_device *dev, int port, int queue)

{

	int ret;



	ret = ksz_pwrite32(dev, port, REG_PORT_MTI_QUEUE_INDEX__4, queue);

	if (ret)

		return ret;



	return ksz_setup_tc_mode(dev, port, MTI_SCHEDULE_STRICT_PRIO,

				 MTI_SHAPING_OFF);

}



static int ksz_queue_set_wrr(struct ksz_device *dev, int port, int queue,

			     int weight)

{

	int ret;



	ret = ksz_pwrite32(dev, port, REG_PORT_MTI_QUEUE_INDEX__4, queue);

	if (ret)

		return ret;



	ret = ksz_setup_tc_mode(dev, port, MTI_SCHEDULE_WRR,

				MTI_SHAPING_OFF);

	if (ret)

		return ret;



	return ksz_pwrite8(dev, port, KSZ9477_PORT_MTI_QUEUE_CTRL_1, weight);

}



static int ksz_tc_ets_add(struct ksz_device *dev, int port,

			  struct tc_ets_qopt_offload_replace_params *p)

{

	int ret, band, tc_prio;

	u32 queue_map = 0;



	/* In order to ensure proper prioritization, it is necessary to set the

	 * rate limit for the related queue to zero. Otherwise strict priority

	 * or WRR mode will not work. This is a hardware limitation.

	 */

	ret = ksz_disable_egress_rate_limit(dev, port);

	if (ret)

		return ret;



	/* Configure queue scheduling mode for all bands. Currently only strict

	 * prio mode is supported.

	 */

	for (band = 0; band < p->bands; band++) {

		int queue = ksz_ets_band_to_queue(p, band);



		ret = ksz_queue_set_strict(dev, port, queue);

		if (ret)

			return ret;

	}



	/* Configure the mapping between traffic classes and queues. Note:

	 * priomap variable support 16 traffic classes, but the chip can handle

	 * only 8 classes.

	 */

	for (tc_prio = 0; tc_prio < ARRAY_SIZE(p->priomap); tc_prio++) {

		int queue;



		if (tc_prio > KSZ9477_MAX_TC_PRIO)

			break;



		queue = ksz_ets_band_to_queue(p, p->priomap[tc_prio]);

		queue_map |= queue << (tc_prio * KSZ9477_PORT_TC_MAP_S);

	}



	return ksz_pwrite32(dev, port, KSZ9477_PORT_MRI_TC_MAP__4, queue_map);

}



static int ksz_tc_ets_del(struct ksz_device *dev, int port)

{

	int ret, queue, tc_prio, s;

	u32 queue_map = 0;



	/* To restore the default chip configuration, set all queues to use the

	 * WRR scheduler with a weight of 1.

	 */

	for (queue = 0; queue < dev->info->num_tx_queues; queue++) {

		ret = ksz_queue_set_wrr(dev, port, queue,

					KSZ9477_DEFAULT_WRR_WEIGHT);

		if (ret)

			return ret;

	}



	switch (dev->info->num_tx_queues) {

	case 2:

		s = 2;

		break;

	case 4:

		s = 1;

		break;

	case 8:

		s = 0;

		break;

	default:

		return -EINVAL;

	}



	/* Revert the queue mapping for TC-priority to its default setting on

	 * the chip.

	 */

	for (tc_prio = 0; tc_prio <= KSZ9477_MAX_TC_PRIO; tc_prio++) {

		int queue;



		queue = tc_prio >> s;

		queue_map |= queue << (tc_prio * KSZ9477_PORT_TC_MAP_S);

	}



	return ksz_pwrite32(dev, port, KSZ9477_PORT_MRI_TC_MAP__4, queue_map);

}



static int ksz_tc_ets_validate(struct ksz_device *dev, int port,

			       struct tc_ets_qopt_offload_replace_params *p)

{

	int band;



	/* Since it is not feasible to share one port among multiple qdisc,

	 * the user must configure all available queues appropriately.

	 */

	if (p->bands != dev->info->num_tx_queues) {

		dev_err(dev->dev, "Not supported amount of bands. It should be %d\n",

			dev->info->num_tx_queues);

		return -EOPNOTSUPP;

	}



	for (band = 0; band < p->bands; ++band) {

		/* The KSZ switches utilize a weighted round robin configuration

		 * where a certain number of packets can be transmitted from a

		 * queue before the next queue is serviced. For more information

		 * on this, refer to section 5.2.8.4 of the KSZ8565R

		 * documentation on the Port Transmit Queue Control 1 Register.

		 * However, the current ETS Qdisc implementation (as of February

		 * 2023) assigns a weight to each queue based on the number of

		 * bytes or extrapolated bandwidth in percentages. Since this

		 * differs from the KSZ switches' method and we don't want to

		 * fake support by converting bytes to packets, it is better to

		 * return an error instead.

		 */

		if (p->quanta[band]) {

			dev_err(dev->dev, "Quanta/weights configuration is not supported.\n");

			return -EOPNOTSUPP;

		}

	}



	return 0;

}



static int ksz_tc_setup_qdisc_ets(struct dsa_switch *ds, int port,

				  struct tc_ets_qopt_offload *qopt)

{

	struct ksz_device *dev = ds->priv;

	int ret;



	if (!dev->info->tc_ets_supported)

		return -EOPNOTSUPP;



	if (qopt->parent != TC_H_ROOT) {

		dev_err(dev->dev, "Parent should be \"root\"\n");

		return -EOPNOTSUPP;

	}



	switch (qopt->command) {

	case TC_ETS_REPLACE:

		ret = ksz_tc_ets_validate(dev, port, &qopt->replace_params);

		if (ret)

			return ret;



		return ksz_tc_ets_add(dev, port, &qopt->replace_params);

	case TC_ETS_DESTROY:

		return ksz_tc_ets_del(dev, port);

	case TC_ETS_STATS:

	case TC_ETS_GRAFT:

		return -EOPNOTSUPP;

	}



	return -EOPNOTSUPP;

}



static int ksz_setup_tc(struct dsa_switch *ds, int port,

			enum tc_setup_type type, void *type_data)

{

	switch (type) {

	case TC_SETUP_QDISC_CBS:

		return ksz_setup_tc_cbs(ds, port, type_data);

	case TC_SETUP_QDISC_ETS:

		return ksz_tc_setup_qdisc_ets(ds, port, type_data);

	default:

		return -EOPNOTSUPP;

	}

drivers/net/dsa/microchip/ksz_common.h

+12 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ struct ksz_chip_data { 
	u8 port_nirqs;

	u8 num_tx_queues;

	bool tc_cbs_supported;

	bool tc_ets_supported;

	const struct ksz_dev_ops *ops;

	bool phy_errata_9477;

	bool ksz87xx_eee_link_erratum;
@@ -649,6 +650,14 @@ static inline int is_lan937x(struct ksz_device *dev) 
#define KSZ8_LEGAL_PACKET_SIZE		1518

#define KSZ9477_MAX_FRAME_SIZE		9000



#define KSZ9477_REG_PORT_OUT_RATE_0	0x0420

#define KSZ9477_OUT_RATE_NO_LIMIT	0



#define KSZ9477_PORT_MRI_TC_MAP__4	0x0808



#define KSZ9477_PORT_TC_MAP_S		4

#define KSZ9477_MAX_TC_PRIO		7



/* CBS related registers */

#define REG_PORT_MTI_QUEUE_INDEX__4	0x0900
@@ -662,6 +671,9 @@ static inline int is_lan937x(struct ksz_device *dev) 
#define MTI_SHAPING_SRP			1

#define MTI_SHAPING_TIME_AWARE		2



#define KSZ9477_PORT_MTI_QUEUE_CTRL_1	0x0915

#define KSZ9477_DEFAULT_WRR_WEIGHT	1



#define REG_PORT_MTI_HI_WATER_MARK	0x0916

#define REG_PORT_MTI_LO_WATER_MARK	0x0918