[PATCH v2 net-next 0/1] net: dsa: hellcreek: Add TAPRIO offloading

@@ -3,7 +3,7 @@
  * DSA driver for:
  * Hirschmann Hellcreek TSN switch.
  *
- * Copyright (C) 2019,2020 Linutronix GmbH
+ * Copyright (C) 2019-2021 Linutronix GmbH
  * Author Kurt Kanzenbach <kurt@linutronix.de>
  */
 

@@ -153,6 +153,13 @@ static void hellcreek_select_vlan(struct hellcreek *hellcreek, int vid,
 	hellcreek_write(hellcreek, val, HR_VIDCFG);
 }
 
+static void hellcreek_select_tgd(struct hellcreek *hellcreek, int port)
+{
+	u16 val = port << TR_TGDSEL_TDGSEL_SHIFT;
+
+	hellcreek_write(hellcreek, val, TR_TGDSEL);
+}
+
 static int hellcreek_wait_until_ready(struct hellcreek *hellcreek)
 {
 	u16 val;

@@ -1125,6 +1132,291 @@ hellcreek_port_prechangeupper(struct dsa_switch *ds, int port,
 	return ret;
 }
 
+static void hellcreek_setup_gcl(struct hellcreek *hellcreek, int port,
+				const struct tc_taprio_qopt_offload *schedule)
+{
+	const struct tc_taprio_sched_entry *cur, *initial, *next;
+	size_t i;
+
+	cur = initial = &schedule->entries[0];
+	next = cur + 1;
+
+	for (i = 1; i <= schedule->num_entries; ++i) {
+		u16 data;
+		u8 gates;
+
+		cur++;
+		next++;
+
+		if (i == schedule->num_entries)
+			gates = initial->gate_mask ^
+				cur->gate_mask;
+		else
+			gates = next->gate_mask ^
+				cur->gate_mask;
+
+		data = gates;
+
+		if (i == schedule->num_entries)
+			data |= TR_GCLDAT_GCLWRLAST;
+
+		/* Gates states */
+		hellcreek_write(hellcreek, data, TR_GCLDAT);
+
+		/* Time interval */
+		hellcreek_write(hellcreek,
+				cur->interval & 0x0000ffff,
+				TR_GCLTIL);
+		hellcreek_write(hellcreek,
+				(cur->interval & 0xffff0000) >> 16,
+				TR_GCLTIH);
+
+		/* Commit entry */
+		data = ((i - 1) << TR_GCLCMD_GCLWRADR_SHIFT) |
+			(initial->gate_mask <<
+			 TR_GCLCMD_INIT_GATE_STATES_SHIFT);
+		hellcreek_write(hellcreek, data, TR_GCLCMD);
+	}
+}
+
+static void hellcreek_set_cycle_time(struct hellcreek *hellcreek,
+				     const struct tc_taprio_qopt_offload *schedule)
+{
+	u32 cycle_time = schedule->cycle_time;
+
+	hellcreek_write(hellcreek, cycle_time & 0x0000ffff, TR_CTWRL);
+	hellcreek_write(hellcreek, (cycle_time & 0xffff0000) >> 16, TR_CTWRH);
+}
+
+static void hellcreek_switch_schedule(struct hellcreek *hellcreek,
+				      ktime_t start_time)
+{
+	struct timespec64 ts = ktime_to_timespec64(start_time);
+
+	/* Start schedule at this point of time */
+	hellcreek_write(hellcreek, ts.tv_nsec & 0x0000ffff, TR_ESTWRL);
+	hellcreek_write(hellcreek, (ts.tv_nsec & 0xffff0000) >> 16, TR_ESTWRH);
+
+	/* Arm timer, set seconds and switch schedule */
+	hellcreek_write(hellcreek, TR_ESTCMD_ESTARM | TR_ESTCMD_ESTSWCFG |
+			((ts.tv_sec & TR_ESTCMD_ESTSEC_MASK) <<
+			 TR_ESTCMD_ESTSEC_SHIFT), TR_ESTCMD);
+}
+
+static bool hellcreek_schedule_startable(struct hellcreek *hellcreek, int port)
+{
+	struct hellcreek_port *hellcreek_port = &hellcreek->ports[port];
+	s64 base_time_ns, current_ns;
+
+	/* The switch allows a schedule to be started only eight seconds within
+	 * the future. Therefore, check the current PTP time if the schedule is
+	 * startable or not.
+	 */
+
+	/* Use the "cached" time. That should be alright, as it's updated quite
+	 * frequently in the PTP code.
+	 */
+	mutex_lock(&hellcreek->ptp_lock);
+	current_ns = hellcreek->seconds * NSEC_PER_SEC + hellcreek->last_ts;
+	mutex_unlock(&hellcreek->ptp_lock);
+
+	/* Calculate difference to admin base time */
+	base_time_ns = ktime_to_ns(hellcreek_port->current_schedule->base_time);
+
+	if (base_time_ns - current_ns < (s64)8 * NSEC_PER_SEC)
+		return true;
+
+	return false;
+}
+
+static void hellcreek_start_schedule(struct hellcreek *hellcreek, int port)
+{
+	struct hellcreek_port *hellcreek_port = &hellcreek->ports[port];
+	ktime_t base_time, current_time;
+	s64 current_ns;
+	u32 cycle_time;
+
+	/* First select port */
+	hellcreek_select_tgd(hellcreek, port);
+
+	/* Forward base time into the future if needed */
+	mutex_lock(&hellcreek->ptp_lock);
+	current_ns = hellcreek->seconds * NSEC_PER_SEC + hellcreek->last_ts;
+	mutex_unlock(&hellcreek->ptp_lock);
+
+	current_time = ns_to_ktime(current_ns);
+	base_time    = hellcreek_port->current_schedule->base_time;
+	cycle_time   = hellcreek_port->current_schedule->cycle_time;
+
+	if (ktime_compare(current_time, base_time) > 0) {
+		s64 n;
+
+		n = div64_s64(ktime_sub_ns(current_time, base_time), cycle_time);
+		base_time = ktime_add_ns(base_time, (n + 1) * cycle_time);
+	}
+
+	/* Set admin base time and switch schedule */
+	hellcreek_switch_schedule(hellcreek, base_time);
+
+	taprio_offload_free(hellcreek_port->current_schedule);
+	hellcreek_port->current_schedule = NULL;
+
+	dev_dbg(hellcreek->dev, "Armed EST timer for port %d\n",
+		hellcreek_port->port);
+}
+
+static void hellcreek_check_schedule(struct work_struct *work)
+{
+	struct delayed_work *dw = to_delayed_work(work);
+	struct hellcreek_port *hellcreek_port;
+	struct hellcreek *hellcreek;
+	bool startable;
+
+	hellcreek_port = dw_to_hellcreek_port(dw);
+	hellcreek = hellcreek_port->hellcreek;
+
+	mutex_lock(&hellcreek->reg_lock);
+
+	/* Check starting time */
+	startable = hellcreek_schedule_startable(hellcreek,
+						 hellcreek_port->port);
+	if (startable) {
+		hellcreek_start_schedule(hellcreek, hellcreek_port->port);
+		mutex_unlock(&hellcreek->reg_lock);
+		return;
+	}
+
+	mutex_unlock(&hellcreek->reg_lock);
+
+	/* Reschedule */
+	schedule_delayed_work(&hellcreek_port->schedule_work,
+			      HELLCREEK_SCHEDULE_PERIOD);
+}
+
+static int hellcreek_port_set_schedule(struct dsa_switch *ds, int port,
+				       struct tc_taprio_qopt_offload *taprio)
+{
+	struct hellcreek *hellcreek = ds->priv;
+	struct hellcreek_port *hellcreek_port;
+	bool startable;
+	u16 ctrl;
+
+	hellcreek_port = &hellcreek->ports[port];
+
+	dev_dbg(hellcreek->dev, "Configure traffic schedule on port %d\n",
+		port);
+
+	/* First cancel delayed work */
+	cancel_delayed_work_sync(&hellcreek_port->schedule_work);
+
+	mutex_lock(&hellcreek->reg_lock);
+
+	if (hellcreek_port->current_schedule) {
+		taprio_offload_free(hellcreek_port->current_schedule);
+		hellcreek_port->current_schedule = NULL;
+	}
+	hellcreek_port->current_schedule = taprio_offload_get(taprio);
+
+	/* Then select port */
+	hellcreek_select_tgd(hellcreek, port);
+
+	/* Enable gating and keep defaults */
+	ctrl = (0xff << TR_TGDCTRL_ADMINGATESTATES_SHIFT) | TR_TGDCTRL_GATE_EN;
+	hellcreek_write(hellcreek, ctrl, TR_TGDCTRL);
+
+	/* Cancel pending schedule */
+	hellcreek_write(hellcreek, 0x00, TR_ESTCMD);
+
+	/* Setup a new schedule */
+	hellcreek_setup_gcl(hellcreek, port, hellcreek_port->current_schedule);
+
+	/* Configure cycle time */
+	hellcreek_set_cycle_time(hellcreek, hellcreek_port->current_schedule);
+
+	/* Check starting time */
+	startable = hellcreek_schedule_startable(hellcreek, port);
+	if (startable) {
+		hellcreek_start_schedule(hellcreek, port);
+		mutex_unlock(&hellcreek->reg_lock);
+		return 0;
+	}
+
+	mutex_unlock(&hellcreek->reg_lock);
+
+	/* Schedule periodic schedule check */
+	schedule_delayed_work(&hellcreek_port->schedule_work,
+			      HELLCREEK_SCHEDULE_PERIOD);
+
+	return 0;
+}
+
+static int hellcreek_port_del_schedule(struct dsa_switch *ds, int port)
+{
+	struct hellcreek *hellcreek = ds->priv;
+	struct hellcreek_port *hellcreek_port;
+
+	hellcreek_port = &hellcreek->ports[port];
+
+	dev_dbg(hellcreek->dev, "Remove traffic schedule on port %d\n", port);
+
+	/* First cancel delayed work */
+	cancel_delayed_work_sync(&hellcreek_port->schedule_work);
+
+	mutex_lock(&hellcreek->reg_lock);
+
+	if (hellcreek_port->current_schedule) {
+		taprio_offload_free(hellcreek_port->current_schedule);
+		hellcreek_port->current_schedule = NULL;
+	}
+
+	/* Then select port */
+	hellcreek_select_tgd(hellcreek, port);
+
+	/* Disable gating and return to regular switching flow */
+	hellcreek_write(hellcreek, 0xff << TR_TGDCTRL_ADMINGATESTATES_SHIFT,
+			TR_TGDCTRL);
+
+	mutex_unlock(&hellcreek->reg_lock);
+
+	return 0;
+}
+
+static bool hellcreek_validate_schedule(struct hellcreek *hellcreek,
+					struct tc_taprio_qopt_offload *schedule)
+{
+	/* Does this hellcreek version support Qbv in hardware? */
+	if (!hellcreek->pdata->qbv_support)
+		return false;
+
+	/* cycle time can only be 32bit */
+	if (schedule->cycle_time > (u32)-1)
+		return false;
+
+	/* cycle time extension is not supported */
+	if (schedule->cycle_time_extension)
+		return false;
+
+	return true;
+}
+
+static int hellcreek_port_setup_tc(struct dsa_switch *ds, int port,
+				   enum tc_setup_type type, void *type_data)
+{
+	struct tc_taprio_qopt_offload *taprio = type_data;
+	struct hellcreek *hellcreek = ds->priv;
+
+	if (type != TC_SETUP_QDISC_TAPRIO)
+		return -EOPNOTSUPP;
+
+	if (!hellcreek_validate_schedule(hellcreek, taprio))
+		return -EOPNOTSUPP;
+
+	if (taprio->enable)
+		return hellcreek_port_set_schedule(ds, port, taprio);
+
+	return hellcreek_port_del_schedule(ds, port);
+}
+
 static const struct dsa_switch_ops hellcreek_ds_ops = {
 	.get_ethtool_stats   = hellcreek_get_ethtool_stats,
 	.get_sset_count	     = hellcreek_get_sset_count,

@@ -1143,6 +1435,7 @@ static const struct dsa_switch_ops hellcreek_ds_ops = {
 	.port_hwtstamp_get   = hellcreek_port_hwtstamp_get,
 	.port_prechangeupper = hellcreek_port_prechangeupper,
 	.port_rxtstamp	     = hellcreek_port_rxtstamp,
+	.port_setup_tc	     = hellcreek_port_setup_tc,
 	.port_stp_state_set  = hellcreek_port_stp_state_set,
 	.port_txtstamp	     = hellcreek_port_txtstamp,
 	.port_vlan_add	     = hellcreek_vlan_add,

@@ -1197,6 +1490,9 @@ static int hellcreek_probe(struct platform_device *pdev)
 
 		port->hellcreek	= hellcreek;
 		port->port	= i;
+
+		INIT_DELAYED_WORK(&port->schedule_work,
+				  hellcreek_check_schedule);
 	}
 
 	mutex_init(&hellcreek->reg_lock);

@@ -3,7 +3,7 @@
  * DSA driver for:
  * Hirschmann Hellcreek TSN switch.
  *
- * Copyright (C) 2019,2020 Linutronix GmbH
+ * Copyright (C) 2019-2021 Linutronix GmbH
  * Author Kurt Kanzenbach <kurt@linutronix.de>
  */
 

@@ -21,6 +21,7 @@
 #include <linux/ptp_clock_kernel.h>
 #include <linux/timecounter.h>
 #include <net/dsa.h>
+#include <net/pkt_sched.h>
 
 /* Ports:
  *  - 0: CPU

@@ -246,6 +247,10 @@ struct hellcreek_port {
 
 	/* Per-port timestamping resources */
 	struct hellcreek_port_hwtstamp port_hwtstamp;
+
+	/* Per-port Qbv schedule information */
+	struct tc_taprio_qopt_offload *current_schedule;
+	struct delayed_work schedule_work;
 };
 
 struct hellcreek_fdb_entry {

@@ -283,4 +288,8 @@ struct hellcreek {
 	size_t fdb_entries;
 };
 
+#define HELLCREEK_SCHEDULE_PERIOD	(2 * HZ)
+#define dw_to_hellcreek_port(dw)				\
+	container_of(dw, struct hellcreek_port, schedule_work)
+
 #endif /* _HELLCREEK_H_ */