net: dsa: felix: Configure Time-Aware Scheduler via taprio offload

Ocelot VSC9959 switch supports time-based egress shaping in hardware
according to IEEE 802.1Qbv. This patch add support for TAS configuration
on egress port of VSC9959 switch.

Felix driver is an instance of Ocelot family, with a DSA front-end. The
patch uses tc taprio hardware offload to setup TAS set function on felix
driver.
Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/ocelot/felix.c

@@ -237,6 +237,10 @@ static void felix_phylink_mac_config(struct dsa_switch *ds, int port,
 
 	if (felix->info->pcs_init)
 		felix->info->pcs_init(ocelot, port, link_an_mode, state);
+
+	if (felix->info->port_sched_speed_set)
+		felix->info->port_sched_speed_set(ocelot, port,
+						  state->speed);
 }
 
 static void felix_phylink_mac_an_restart(struct dsa_switch *ds, int port)
@@ -730,6 +734,19 @@ static void felix_port_policer_del(struct dsa_switch *ds, int port)
 	ocelot_port_policer_del(ocelot, port);
 }
 
+static int felix_port_setup_tc(struct dsa_switch *ds, int port,
+			       enum tc_setup_type type,
+			       void *type_data)
+{
+	struct ocelot *ocelot = ds->priv;
+	struct felix *felix = ocelot_to_felix(ocelot);
+
+	if (felix->info->port_setup_tc)
+		return felix->info->port_setup_tc(ds, port, type, type_data);
+	else
+		return -EOPNOTSUPP;
+}
+
 static const struct dsa_switch_ops felix_switch_ops = {
 	.get_tag_protocol	= felix_get_tag_protocol,
 	.setup			= felix_setup,
@@ -768,6 +785,7 @@ static const struct dsa_switch_ops felix_switch_ops = {
 	.cls_flower_add		= felix_cls_flower_add,
 	.cls_flower_del		= felix_cls_flower_del,
 	.cls_flower_stats	= felix_cls_flower_stats,
+	.port_setup_tc          = felix_port_setup_tc,
 };
 
 static struct felix_info *felix_instance_tbl[] = {
@@ -856,6 +874,7 @@ static int felix_pci_probe(struct pci_dev *pdev,
 
 	ds->dev = &pdev->dev;
 	ds->num_ports = felix->info->num_ports;
+	ds->num_tx_queues = felix->info->num_tx_queues;
 	ds->ops = &felix_switch_ops;
 	ds->priv = ocelot;
 	felix->ds = ds;

drivers/net/dsa/ocelot/felix.h

@@ -20,6 +20,7 @@ struct felix_info {
 	const struct ocelot_stat_layout	*stats_layout;
 	unsigned int			num_stats;
 	int				num_ports;
+	int                             num_tx_queues;
 	struct vcap_field		*vcap_is2_keys;
 	struct vcap_field		*vcap_is2_actions;
 	const struct vcap_props		*vcap;
@@ -35,6 +36,10 @@ struct felix_info {
 				  struct phylink_link_state *state);
 	int	(*prevalidate_phy_mode)(struct ocelot *ocelot, int port,
 					phy_interface_t phy_mode);
+	int	(*port_setup_tc)(struct dsa_switch *ds, int port,
+				 enum tc_setup_type type, void *type_data);
+	void	(*port_sched_speed_set)(struct ocelot *ocelot, int port,
+					u32 speed);
 };
 
 extern struct felix_info		felix_info_vsc9959;

drivers/net/dsa/ocelot/felix_vsc9959.c

@@ -3,9 +3,12 @@
  * Copyright 2018-2019 NXP Semiconductors
  */
 #include <linux/fsl/enetc_mdio.h>
+#include <soc/mscc/ocelot_qsys.h>
 #include <soc/mscc/ocelot_vcap.h>
+#include <soc/mscc/ocelot_ptp.h>
 #include <soc/mscc/ocelot_sys.h>
 #include <soc/mscc/ocelot.h>
+#include <net/pkt_sched.h>
 #include <linux/iopoll.h>
 #include <linux/pci.h>
 #include "felix.h"
@@ -27,6 +30,8 @@
 #define USXGMII_LPA_DUPLEX(lpa)		(((lpa) & GENMASK(12, 12)) >> 12)
 #define USXGMII_LPA_SPEED(lpa)		(((lpa) & GENMASK(11, 9)) >> 9)
 
+#define VSC9959_TAS_GCL_ENTRY_MAX	63
+
 enum usxgmii_speed {
 	USXGMII_SPEED_10	= 0,
 	USXGMII_SPEED_100	= 1,
@@ -1209,6 +1214,138 @@ static void vsc9959_mdio_bus_free(struct ocelot *ocelot)
 	mdiobus_unregister(felix->imdio);
 }
 
+static void vsc9959_sched_speed_set(struct ocelot *ocelot, int port,
+				    u32 speed)
+{
+	ocelot_rmw_rix(ocelot,
+		       QSYS_TAG_CONFIG_LINK_SPEED(speed),
+		       QSYS_TAG_CONFIG_LINK_SPEED_M,
+		       QSYS_TAG_CONFIG, port);
+}
+
+static void vsc9959_new_base_time(struct ocelot *ocelot, ktime_t base_time,
+				  u64 cycle_time,
+				  struct timespec64 *new_base_ts)
+{
+	struct timespec64 ts;
+	ktime_t new_base_time;
+	ktime_t current_time;
+
+	ocelot_ptp_gettime64(&ocelot->ptp_info, &ts);
+	current_time = timespec64_to_ktime(ts);
+	new_base_time = base_time;
+
+	if (base_time < current_time) {
+		u64 nr_of_cycles = current_time - base_time;
+
+		do_div(nr_of_cycles, cycle_time);
+		new_base_time += cycle_time * (nr_of_cycles + 1);
+	}
+
+	*new_base_ts = ktime_to_timespec64(new_base_time);
+}
+
+static u32 vsc9959_tas_read_cfg_status(struct ocelot *ocelot)
+{
+	return ocelot_read(ocelot, QSYS_TAS_PARAM_CFG_CTRL);
+}
+
+static void vsc9959_tas_gcl_set(struct ocelot *ocelot, const u32 gcl_ix,
+				struct tc_taprio_sched_entry *entry)
+{
+	ocelot_write(ocelot,
+		     QSYS_GCL_CFG_REG_1_GCL_ENTRY_NUM(gcl_ix) |
+		     QSYS_GCL_CFG_REG_1_GATE_STATE(entry->gate_mask),
+		     QSYS_GCL_CFG_REG_1);
+	ocelot_write(ocelot, entry->interval, QSYS_GCL_CFG_REG_2);
+}
+
+static int vsc9959_qos_port_tas_set(struct ocelot *ocelot, int port,
+				    struct tc_taprio_qopt_offload *taprio)
+{
+	struct timespec64 base_ts;
+	int ret, i;
+	u32 val;
+
+	if (!taprio->enable) {
+		ocelot_rmw_rix(ocelot,
+			       QSYS_TAG_CONFIG_INIT_GATE_STATE(0xFF),
+			       QSYS_TAG_CONFIG_ENABLE |
+			       QSYS_TAG_CONFIG_INIT_GATE_STATE_M,
+			       QSYS_TAG_CONFIG, port);
+
+		return 0;
+	}
+
+	if (taprio->cycle_time > NSEC_PER_SEC ||
+	    taprio->cycle_time_extension >= NSEC_PER_SEC)
+		return -EINVAL;
+
+	if (taprio->num_entries > VSC9959_TAS_GCL_ENTRY_MAX)
+		return -ERANGE;
+
+	ocelot_rmw(ocelot, QSYS_TAS_PARAM_CFG_CTRL_PORT_NUM(port) |
+		   QSYS_TAS_PARAM_CFG_CTRL_ALWAYS_GUARD_BAND_SCH_Q,
+		   QSYS_TAS_PARAM_CFG_CTRL_PORT_NUM_M |
+		   QSYS_TAS_PARAM_CFG_CTRL_ALWAYS_GUARD_BAND_SCH_Q,
+		   QSYS_TAS_PARAM_CFG_CTRL);
+
+	/* Hardware errata -  Admin config could not be overwritten if
+	 * config is pending, need reset the TAS module
+	 */
+	val = ocelot_read(ocelot, QSYS_PARAM_STATUS_REG_8);
+	if (val & QSYS_PARAM_STATUS_REG_8_CONFIG_PENDING)
+		return  -EBUSY;
+
+	ocelot_rmw_rix(ocelot,
+		       QSYS_TAG_CONFIG_ENABLE |
+		       QSYS_TAG_CONFIG_INIT_GATE_STATE(0xFF) |
+		       QSYS_TAG_CONFIG_SCH_TRAFFIC_QUEUES(0xFF),
+		       QSYS_TAG_CONFIG_ENABLE |
+		       QSYS_TAG_CONFIG_INIT_GATE_STATE_M |
+		       QSYS_TAG_CONFIG_SCH_TRAFFIC_QUEUES_M,
+		       QSYS_TAG_CONFIG, port);
+
+	vsc9959_new_base_time(ocelot, taprio->base_time,
+			      taprio->cycle_time, &base_ts);
+	ocelot_write(ocelot, base_ts.tv_nsec, QSYS_PARAM_CFG_REG_1);
+	ocelot_write(ocelot, lower_32_bits(base_ts.tv_sec), QSYS_PARAM_CFG_REG_2);
+	val = upper_32_bits(base_ts.tv_sec);
+	ocelot_write(ocelot,
+		     QSYS_PARAM_CFG_REG_3_BASE_TIME_SEC_MSB(val) |
+		     QSYS_PARAM_CFG_REG_3_LIST_LENGTH(taprio->num_entries),
+		     QSYS_PARAM_CFG_REG_3);
+	ocelot_write(ocelot, taprio->cycle_time, QSYS_PARAM_CFG_REG_4);
+	ocelot_write(ocelot, taprio->cycle_time_extension, QSYS_PARAM_CFG_REG_5);
+
+	for (i = 0; i < taprio->num_entries; i++)
+		vsc9959_tas_gcl_set(ocelot, i, &taprio->entries[i]);
+
+	ocelot_rmw(ocelot, QSYS_TAS_PARAM_CFG_CTRL_CONFIG_CHANGE,
+		   QSYS_TAS_PARAM_CFG_CTRL_CONFIG_CHANGE,
+		   QSYS_TAS_PARAM_CFG_CTRL);
+
+	ret = readx_poll_timeout(vsc9959_tas_read_cfg_status, ocelot, val,
+				 !(val & QSYS_TAS_PARAM_CFG_CTRL_CONFIG_CHANGE),
+				 10, 100000);
+
+	return ret;
+}
+
+static int vsc9959_port_setup_tc(struct dsa_switch *ds, int port,
+				 enum tc_setup_type type,
+				 void *type_data)
+{
+	struct ocelot *ocelot = ds->priv;
+
+	switch (type) {
+	case TC_SETUP_QDISC_TAPRIO:
+		return vsc9959_qos_port_tas_set(ocelot, port, type_data);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 struct felix_info felix_info_vsc9959 = {
 	.target_io_res		= vsc9959_target_io_res,
 	.port_io_res		= vsc9959_port_io_res,
@@ -1224,6 +1361,7 @@ struct felix_info felix_info_vsc9959 = {
 	.shared_queue_sz	= 128 * 1024,
 	.num_mact_rows		= 2048,
 	.num_ports		= 6,
+	.num_tx_queues		= FELIX_NUM_TC,
 	.switch_pci_bar		= 4,
 	.imdio_pci_bar		= 0,
 	.mdio_bus_alloc		= vsc9959_mdio_bus_alloc,
@@ -1232,4 +1370,6 @@ struct felix_info felix_info_vsc9959 = {
 	.pcs_an_restart		= vsc9959_pcs_an_restart,
 	.pcs_link_state		= vsc9959_pcs_link_state,
 	.prevalidate_phy_mode	= vsc9959_prevalidate_phy_mode,
+	.port_setup_tc          = vsc9959_port_setup_tc,
+	.port_sched_speed_set   = vsc9959_sched_speed_set,
 };