xref: /kernel/linux/linux-6.6/drivers/net/ethernet/microchip/lan966x/lan966x_taprio.c

// SPDX-License-Identifier: GPL-2.0+

#include "lan966x_main.h"

#define LAN966X_TAPRIO_TIMEOUT_MS		1000
#define LAN966X_TAPRIO_ENTRIES_PER_PORT		2

/* Minimum supported cycle time in nanoseconds */
#define LAN966X_TAPRIO_MIN_CYCLE_TIME_NS	NSEC_PER_USEC

/* Maximum supported cycle time in nanoseconds */
#define LAN966X_TAPRIO_MAX_CYCLE_TIME_NS	(NSEC_PER_SEC - 1)

/* Total number of TAS GCL entries */
#define LAN966X_TAPRIO_NUM_GCL			256

/* TAPRIO link speeds for calculation of guard band */
enum lan966x_taprio_link_speed {
	LAN966X_TAPRIO_SPEED_NO_GB,
	LAN966X_TAPRIO_SPEED_10,
	LAN966X_TAPRIO_SPEED_100,
	LAN966X_TAPRIO_SPEED_1000,
	LAN966X_TAPRIO_SPEED_2500,
};

/* TAPRIO list states */
enum lan966x_taprio_state {
	LAN966X_TAPRIO_STATE_ADMIN,
	LAN966X_TAPRIO_STATE_ADVANCING,
	LAN966X_TAPRIO_STATE_PENDING,
	LAN966X_TAPRIO_STATE_OPERATING,
	LAN966X_TAPRIO_STATE_TERMINATING,
	LAN966X_TAPRIO_STATE_MAX,
};

/* TAPRIO GCL command */
enum lan966x_taprio_gcl_cmd {
	LAN966X_TAPRIO_GCL_CMD_SET_GATE_STATES = 0,
};

static u32 lan966x_taprio_list_index(struct lan966x_port *port, u8 entry)
{
	return port->chip_port * LAN966X_TAPRIO_ENTRIES_PER_PORT + entry;
}

static u32 lan966x_taprio_list_state_get(struct lan966x_port *port)
{
	struct lan966x *lan966x = port->lan966x;
	u32 val;

	val = lan_rd(lan966x, QSYS_TAS_LST);
	return QSYS_TAS_LST_LIST_STATE_GET(val);
}

static u32 lan966x_taprio_list_index_state_get(struct lan966x_port *port,
					       u32 list)
{
	struct lan966x *lan966x = port->lan966x;

	lan_rmw(QSYS_TAS_CFG_CTRL_LIST_NUM_SET(list),
		QSYS_TAS_CFG_CTRL_LIST_NUM,
		lan966x, QSYS_TAS_CFG_CTRL);

	return lan966x_taprio_list_state_get(port);
}

static void lan966x_taprio_list_state_set(struct lan966x_port *port,
					  u32 state)
{
	struct lan966x *lan966x = port->lan966x;

	lan_rmw(QSYS_TAS_LST_LIST_STATE_SET(state),
		QSYS_TAS_LST_LIST_STATE,
		lan966x, QSYS_TAS_LST);
}

static int lan966x_taprio_list_shutdown(struct lan966x_port *port,
					u32 list)
{
	struct lan966x *lan966x = port->lan966x;
	bool pending, operating;
	unsigned long end;
	u32 state;

	end = jiffies +  msecs_to_jiffies(LAN966X_TAPRIO_TIMEOUT_MS);
	/* It is required to try multiple times to set the state of list,
	 * because the HW can overwrite this.
	 */
	do {
		state = lan966x_taprio_list_state_get(port);

		pending = false;
		operating = false;

		if (state == LAN966X_TAPRIO_STATE_ADVANCING ||
		    state == LAN966X_TAPRIO_STATE_PENDING) {
			lan966x_taprio_list_state_set(port,
						      LAN966X_TAPRIO_STATE_ADMIN);
			pending = true;
		}

		if (state == LAN966X_TAPRIO_STATE_OPERATING) {
			lan966x_taprio_list_state_set(port,
						      LAN966X_TAPRIO_STATE_TERMINATING);
			operating = true;
		}

		/* If the entry was in pending and now gets in admin, then there
		 * is nothing else to do, so just bail out
		 */
		state = lan966x_taprio_list_state_get(port);
		if (pending &&
		    state == LAN966X_TAPRIO_STATE_ADMIN)
			return 0;

		/* If the list was in operating and now is in terminating or
		 * admin, then is OK to exit but it needs to wait until the list
		 * will get in admin. It is not required to set the state
		 * again.
		 */
		if (operating &&
		    (state == LAN966X_TAPRIO_STATE_TERMINATING ||
		     state == LAN966X_TAPRIO_STATE_ADMIN))
			break;

	} while (!time_after(jiffies, end));

	end = jiffies + msecs_to_jiffies(LAN966X_TAPRIO_TIMEOUT_MS);
	do {
		state = lan966x_taprio_list_state_get(port);
		if (state == LAN966X_TAPRIO_STATE_ADMIN)
			break;

	} while (!time_after(jiffies, end));

	/* If the list was in operating mode, it could be stopped while some
	 * queues where closed, so make sure to restore "all-queues-open"
	 */
	if (operating) {
		lan_wr(QSYS_TAS_GS_CTRL_HSCH_POS_SET(port->chip_port),
		       lan966x, QSYS_TAS_GS_CTRL);

		lan_wr(QSYS_TAS_GATE_STATE_TAS_GATE_STATE_SET(0xff),
		       lan966x, QSYS_TAS_GATE_STATE);
	}

	return 0;
}

static int lan966x_taprio_shutdown(struct lan966x_port *port)
{
	u32 i, list, state;
	int err;

	for (i = 0; i < LAN966X_TAPRIO_ENTRIES_PER_PORT; ++i) {
		list = lan966x_taprio_list_index(port, i);
		state = lan966x_taprio_list_index_state_get(port, list);
		if (state == LAN966X_TAPRIO_STATE_ADMIN)
			continue;

		err = lan966x_taprio_list_shutdown(port, list);
		if (err)
			return err;
	}

	return 0;
}

/* Find a suitable list for a new schedule. First priority is a list in state
 * pending. Second priority is a list in state admin.
 */
static int lan966x_taprio_find_list(struct lan966x_port *port,
				    struct tc_taprio_qopt_offload *qopt,
				    int *new_list, int *obs_list)
{
	int state[LAN966X_TAPRIO_ENTRIES_PER_PORT];
	int list[LAN966X_TAPRIO_ENTRIES_PER_PORT];
	int err, oper = -1;
	u32 i;

	*new_list = -1;
	*obs_list = -1;

	/* If there is already an entry in operating mode, return this list in
	 * obs_list, such that when the new list will get activated the
	 * operating list will be stopped. In this way is possible to have
	 * smooth transitions between the lists
	 */
	for (i = 0; i < LAN966X_TAPRIO_ENTRIES_PER_PORT; ++i) {
		list[i] = lan966x_taprio_list_index(port, i);
		state[i] = lan966x_taprio_list_index_state_get(port, list[i]);
		if (state[i] == LAN966X_TAPRIO_STATE_OPERATING)
			oper = list[i];
	}

	for (i = 0; i < LAN966X_TAPRIO_ENTRIES_PER_PORT; ++i) {
		if (state[i] == LAN966X_TAPRIO_STATE_PENDING) {
			err = lan966x_taprio_shutdown(port);
			if (err)
				return err;

			*new_list = list[i];
			*obs_list = (oper == -1) ? *new_list : oper;
			return 0;
		}
	}

	for (i = 0; i < LAN966X_TAPRIO_ENTRIES_PER_PORT; ++i) {
		if (state[i] == LAN966X_TAPRIO_STATE_ADMIN) {
			*new_list = list[i];
			*obs_list = (oper == -1) ? *new_list : oper;
			return 0;
		}
	}

	return -ENOSPC;
}

static int lan966x_taprio_check(struct tc_taprio_qopt_offload *qopt)
{
	u64 total_time = 0;
	u32 i;

	/* This is not supported by th HW */
	if (qopt->cycle_time_extension)
		return -EOPNOTSUPP;

	/* There is a limited number of gcl entries that can be used, they are
	 * shared by all ports
	 */
	if (qopt->num_entries > LAN966X_TAPRIO_NUM_GCL)
		return -EINVAL;

	/* Don't allow cycle times bigger than 1 sec or smaller than 1 usec */
	if (qopt->cycle_time < LAN966X_TAPRIO_MIN_CYCLE_TIME_NS ||
	    qopt->cycle_time > LAN966X_TAPRIO_MAX_CYCLE_TIME_NS)
		return -EINVAL;

	for (i = 0; i < qopt->num_entries; ++i) {
		struct tc_taprio_sched_entry *entry = &qopt->entries[i];

		/* Don't allow intervals bigger than 1 sec or smaller than 1
		 * usec
		 */
		if (entry->interval < LAN966X_TAPRIO_MIN_CYCLE_TIME_NS ||
		    entry->interval > LAN966X_TAPRIO_MAX_CYCLE_TIME_NS)
			return -EINVAL;

		if (qopt->entries[i].command != TC_TAPRIO_CMD_SET_GATES)
			return -EINVAL;

		total_time += qopt->entries[i].interval;
	}

	/* Don't allow the total time of intervals be bigger than 1 sec */
	if (total_time > LAN966X_TAPRIO_MAX_CYCLE_TIME_NS)
		return -EINVAL;

	/* The HW expects that the cycle time to be at least as big as sum of
	 * each interval of gcl
	 */
	if (qopt->cycle_time < total_time)
		return -EINVAL;

	return 0;
}

static int lan966x_taprio_gcl_free_get(struct lan966x_port *port,
				       unsigned long *free_list)
{
	struct lan966x *lan966x = port->lan966x;
	u32 num_free, state, list;
	u32 base, next, max_list;

	/* By default everything is free */
	bitmap_fill(free_list, LAN966X_TAPRIO_NUM_GCL);
	num_free = LAN966X_TAPRIO_NUM_GCL;

	/* Iterate over all gcl entries and find out which are free. And mark
	 * those that are not free.
	 */
	max_list = lan966x->num_phys_ports * LAN966X_TAPRIO_ENTRIES_PER_PORT;
	for (list = 0; list < max_list; ++list) {
		state = lan966x_taprio_list_index_state_get(port, list);
		if (state == LAN966X_TAPRIO_STATE_ADMIN)
			continue;

		base = lan_rd(lan966x, QSYS_TAS_LIST_CFG);
		base = QSYS_TAS_LIST_CFG_LIST_BASE_ADDR_GET(base);
		next = base;

		do {
			clear_bit(next, free_list);
			num_free--;

			lan_rmw(QSYS_TAS_CFG_CTRL_GCL_ENTRY_NUM_SET(next),
				QSYS_TAS_CFG_CTRL_GCL_ENTRY_NUM,
				lan966x, QSYS_TAS_CFG_CTRL);

			next = lan_rd(lan966x, QSYS_TAS_GCL_CT_CFG2);
			next = QSYS_TAS_GCL_CT_CFG2_NEXT_GCL_GET(next);
		} while (base != next);
	}

	return num_free;
}

static void lan966x_taprio_gcl_setup_entry(struct lan966x_port *port,
					   struct tc_taprio_sched_entry *entry,
					   u32 next_entry)
{
	struct lan966x *lan966x = port->lan966x;

	/* Setup a single gcl entry */
	lan_wr(QSYS_TAS_GCL_CT_CFG_GATE_STATE_SET(entry->gate_mask) |
	       QSYS_TAS_GCL_CT_CFG_HSCH_POS_SET(port->chip_port) |
	       QSYS_TAS_GCL_CT_CFG_OP_TYPE_SET(LAN966X_TAPRIO_GCL_CMD_SET_GATE_STATES),
	       lan966x, QSYS_TAS_GCL_CT_CFG);

	lan_wr(QSYS_TAS_GCL_CT_CFG2_PORT_PROFILE_SET(port->chip_port) |
	       QSYS_TAS_GCL_CT_CFG2_NEXT_GCL_SET(next_entry),
	       lan966x, QSYS_TAS_GCL_CT_CFG2);

	lan_wr(entry->interval, lan966x, QSYS_TAS_GCL_TM_CFG);
}

static int lan966x_taprio_gcl_setup(struct lan966x_port *port,
				    struct tc_taprio_qopt_offload *qopt,
				    int list)
{
	DECLARE_BITMAP(free_list, LAN966X_TAPRIO_NUM_GCL);
	struct lan966x *lan966x = port->lan966x;
	u32 i, base, next;

	if (lan966x_taprio_gcl_free_get(port, free_list) < qopt->num_entries)
		return -ENOSPC;

	/* Select list */
	lan_rmw(QSYS_TAS_CFG_CTRL_LIST_NUM_SET(list),
		QSYS_TAS_CFG_CTRL_LIST_NUM,
		lan966x, QSYS_TAS_CFG_CTRL);

	/* Setup the address of the first gcl entry */
	base = find_first_bit(free_list, LAN966X_TAPRIO_NUM_GCL);
	lan_rmw(QSYS_TAS_LIST_CFG_LIST_BASE_ADDR_SET(base),
		QSYS_TAS_LIST_CFG_LIST_BASE_ADDR,
		lan966x, QSYS_TAS_LIST_CFG);

	/* Iterate over entries and add them to the gcl list */
	next = base;
	for (i = 0; i < qopt->num_entries; ++i) {
		lan_rmw(QSYS_TAS_CFG_CTRL_GCL_ENTRY_NUM_SET(next),
			QSYS_TAS_CFG_CTRL_GCL_ENTRY_NUM,
			lan966x, QSYS_TAS_CFG_CTRL);

		/* If the entry is last, point back to the start of the list */
		if (i == qopt->num_entries - 1)
			next = base;
		else
			next = find_next_bit(free_list, LAN966X_TAPRIO_NUM_GCL,
					     next + 1);

		lan966x_taprio_gcl_setup_entry(port, &qopt->entries[i], next);
	}

	return 0;
}

/* Calculate new base_time based on cycle_time. The HW recommends to have the
 * new base time at least 2 * cycle type + current time
 */
static void lan966x_taprio_new_base_time(struct lan966x *lan966x,
					 const u32 cycle_time,
					 const ktime_t org_base_time,
					 ktime_t *new_base_time)
{
	ktime_t current_time, threshold_time;
	struct timespec64 ts;

	/* Get the current time and calculate the threshold_time */
	lan966x_ptp_gettime64(&lan966x->phc[LAN966X_PHC_PORT].info, &ts);
	current_time = timespec64_to_ktime(ts);
	threshold_time = current_time + (2 * cycle_time);

	/* If the org_base_time is in enough in future just use it */
	if (org_base_time >= threshold_time) {
		*new_base_time = org_base_time;
		return;
	}

	/* If the org_base_time is smaller than current_time, calculate the new
	 * base time as following.
	 */
	if (org_base_time <= current_time) {
		u64 tmp = current_time - org_base_time;
		u32 rem = 0;

		if (tmp > cycle_time)
			div_u64_rem(tmp, cycle_time, &rem);
		rem = cycle_time - rem;
		*new_base_time = threshold_time + rem;
		return;
	}

	/* The only left place for org_base_time is between current_time and
	 * threshold_time. In this case the new_base_time is calculated like
	 * org_base_time + 2 * cycletime
	 */
	*new_base_time = org_base_time + 2 * cycle_time;
}

int lan966x_taprio_speed_set(struct lan966x_port *port, int speed)
{
	struct lan966x *lan966x = port->lan966x;
	u8 taprio_speed;

	switch (speed) {
	case SPEED_10:
		taprio_speed = LAN966X_TAPRIO_SPEED_10;
		break;
	case SPEED_100:
		taprio_speed = LAN966X_TAPRIO_SPEED_100;
		break;
	case SPEED_1000:
		taprio_speed = LAN966X_TAPRIO_SPEED_1000;
		break;
	case SPEED_2500:
		taprio_speed = LAN966X_TAPRIO_SPEED_2500;
		break;
	default:
		return -EINVAL;
	}

	lan_rmw(QSYS_TAS_PROFILE_CFG_LINK_SPEED_SET(taprio_speed),
		QSYS_TAS_PROFILE_CFG_LINK_SPEED,
		lan966x, QSYS_TAS_PROFILE_CFG(port->chip_port));

	return 0;
}

int lan966x_taprio_add(struct lan966x_port *port,
		       struct tc_taprio_qopt_offload *qopt)
{
	struct lan966x *lan966x = port->lan966x;
	int err, new_list, obs_list;
	struct timespec64 ts;
	ktime_t base_time;

	err = lan966x_taprio_check(qopt);
	if (err)
		return err;

	err = lan966x_taprio_find_list(port, qopt, &new_list, &obs_list);
	if (err)
		return err;

	err = lan966x_taprio_gcl_setup(port, qopt, new_list);
	if (err)
		return err;

	lan966x_taprio_new_base_time(lan966x, qopt->cycle_time,
				     qopt->base_time, &base_time);

	ts = ktime_to_timespec64(base_time);
	lan_wr(QSYS_TAS_BT_NSEC_NSEC_SET(ts.tv_nsec),
	       lan966x, QSYS_TAS_BT_NSEC);

	lan_wr(lower_32_bits(ts.tv_sec),
	       lan966x, QSYS_TAS_BT_SEC_LSB);

	lan_wr(QSYS_TAS_BT_SEC_MSB_SEC_MSB_SET(upper_32_bits(ts.tv_sec)),
	       lan966x, QSYS_TAS_BT_SEC_MSB);

	lan_wr(qopt->cycle_time, lan966x, QSYS_TAS_CT_CFG);

	lan_rmw(QSYS_TAS_STARTUP_CFG_OBSOLETE_IDX_SET(obs_list),
		QSYS_TAS_STARTUP_CFG_OBSOLETE_IDX,
		lan966x, QSYS_TAS_STARTUP_CFG);

	/* Start list processing */
	lan_rmw(QSYS_TAS_LST_LIST_STATE_SET(LAN966X_TAPRIO_STATE_ADVANCING),
		QSYS_TAS_LST_LIST_STATE,
		lan966x, QSYS_TAS_LST);

	return err;
}

int lan966x_taprio_del(struct lan966x_port *port)
{
	return lan966x_taprio_shutdown(port);
}

void lan966x_taprio_init(struct lan966x *lan966x)
{
	int num_taprio_lists;
	int p;

	lan_wr(QSYS_TAS_STM_CFG_REVISIT_DLY_SET((256 * 1000) /
						lan966x_ptp_get_period_ps()),
	       lan966x, QSYS_TAS_STM_CFG);

	num_taprio_lists = lan966x->num_phys_ports *
			   LAN966X_TAPRIO_ENTRIES_PER_PORT;

	/* For now we always use guard band on all queues */
	lan_rmw(QSYS_TAS_CFG_CTRL_LIST_NUM_MAX_SET(num_taprio_lists) |
		QSYS_TAS_CFG_CTRL_ALWAYS_GB_SCH_Q_SET(1),
		QSYS_TAS_CFG_CTRL_LIST_NUM_MAX |
		QSYS_TAS_CFG_CTRL_ALWAYS_GB_SCH_Q,
		lan966x, QSYS_TAS_CFG_CTRL);

	for (p = 0; p < lan966x->num_phys_ports; p++)
		lan_rmw(QSYS_TAS_PROFILE_CFG_PORT_NUM_SET(p),
			QSYS_TAS_PROFILE_CFG_PORT_NUM,
			lan966x, QSYS_TAS_PROFILE_CFG(p));
}

void lan966x_taprio_deinit(struct lan966x *lan966x)
{
	int p;

	for (p = 0; p < lan966x->num_phys_ports; ++p) {
		if (!lan966x->ports[p])
			continue;

		lan966x_taprio_del(lan966x->ports[p]);
	}
}