xref: /kernel/linux/linux-6.6/drivers/net/ethernet/microchip/sparx5/sparx5_sdlb.c

// SPDX-License-Identifier: GPL-2.0+
/* Microchip Sparx5 Switch driver
 *
 * Copyright (c) 2023 Microchip Technology Inc. and its subsidiaries.
 */

#include "sparx5_main_regs.h"
#include "sparx5_main.h"

struct sparx5_sdlb_group sdlb_groups[SPX5_SDLB_GROUP_CNT] = {
	{ SPX5_SDLB_GROUP_RATE_MAX,    8192 / 1, 64 }, /*  25 G */
	{ 15000000000ULL,              8192 / 1, 64 }, /*  15 G */
	{ 10000000000ULL,              8192 / 1, 64 }, /*  10 G */
	{  5000000000ULL,              8192 / 1, 64 }, /*   5 G */
	{  2500000000ULL,              8192 / 1, 64 }, /* 2.5 G */
	{  1000000000ULL,              8192 / 2, 64 }, /*   1 G */
	{   500000000ULL,              8192 / 2, 64 }, /* 500 M */
	{   100000000ULL,              8192 / 4, 64 }, /* 100 M */
	{    50000000ULL,              8192 / 4, 64 }, /*  50 M */
	{     5000000ULL,              8192 / 8, 64 }  /*   5 M */
};

int sparx5_sdlb_clk_hz_get(struct sparx5 *sparx5)
{
	u32 clk_per_100ps;
	u64 clk_hz;

	clk_per_100ps = HSCH_SYS_CLK_PER_100PS_GET(spx5_rd(sparx5,
							   HSCH_SYS_CLK_PER));
	if (!clk_per_100ps)
		clk_per_100ps = SPX5_CLK_PER_100PS_DEFAULT;

	clk_hz = (10 * 1000 * 1000) / clk_per_100ps;
	return clk_hz *= 1000;
}

static int sparx5_sdlb_pup_interval_get(struct sparx5 *sparx5, u32 max_token,
					u64 max_rate)
{
	u64 clk_hz;

	clk_hz = sparx5_sdlb_clk_hz_get(sparx5);

	return div64_u64((8 * clk_hz * max_token), max_rate);
}

int sparx5_sdlb_pup_token_get(struct sparx5 *sparx5, u32 pup_interval, u64 rate)
{
	u64 clk_hz;

	if (!rate)
		return SPX5_SDLB_PUP_TOKEN_DISABLE;

	clk_hz = sparx5_sdlb_clk_hz_get(sparx5);

	return DIV64_U64_ROUND_UP((rate * pup_interval), (clk_hz * 8));
}

static void sparx5_sdlb_group_disable(struct sparx5 *sparx5, u32 group)
{
	spx5_rmw(ANA_AC_SDLB_PUP_CTRL_PUP_ENA_SET(0),
		 ANA_AC_SDLB_PUP_CTRL_PUP_ENA, sparx5,
		 ANA_AC_SDLB_PUP_CTRL(group));
}

static void sparx5_sdlb_group_enable(struct sparx5 *sparx5, u32 group)
{
	spx5_rmw(ANA_AC_SDLB_PUP_CTRL_PUP_ENA_SET(1),
		 ANA_AC_SDLB_PUP_CTRL_PUP_ENA, sparx5,
		 ANA_AC_SDLB_PUP_CTRL(group));
}

static u32 sparx5_sdlb_group_get_first(struct sparx5 *sparx5, u32 group)
{
	u32 val;

	val = spx5_rd(sparx5, ANA_AC_SDLB_XLB_START(group));

	return ANA_AC_SDLB_XLB_START_LBSET_START_GET(val);
}

static u32 sparx5_sdlb_group_get_next(struct sparx5 *sparx5, u32 group,
				      u32 lb)
{
	u32 val;

	val = spx5_rd(sparx5, ANA_AC_SDLB_XLB_NEXT(lb));

	return ANA_AC_SDLB_XLB_NEXT_LBSET_NEXT_GET(val);
}

static bool sparx5_sdlb_group_is_first(struct sparx5 *sparx5, u32 group,
				       u32 lb)
{
	return lb == sparx5_sdlb_group_get_first(sparx5, group);
}

static bool sparx5_sdlb_group_is_last(struct sparx5 *sparx5, u32 group,
				      u32 lb)
{
	return lb == sparx5_sdlb_group_get_next(sparx5, group, lb);
}

static bool sparx5_sdlb_group_is_empty(struct sparx5 *sparx5, u32 group)
{
	u32 val;

	val = spx5_rd(sparx5, ANA_AC_SDLB_PUP_CTRL(group));

	return ANA_AC_SDLB_PUP_CTRL_PUP_ENA_GET(val) == 0;
}

static u32 sparx5_sdlb_group_get_last(struct sparx5 *sparx5, u32 group)
{
	u32 itr, next;

	itr = sparx5_sdlb_group_get_first(sparx5, group);

	for (;;) {
		next = sparx5_sdlb_group_get_next(sparx5, group, itr);
		if (itr == next)
			return itr;

		itr = next;
	}
}

static bool sparx5_sdlb_group_is_singular(struct sparx5 *sparx5, u32 group)
{
	if (sparx5_sdlb_group_is_empty(sparx5, group))
		return false;

	return sparx5_sdlb_group_get_first(sparx5, group) ==
	       sparx5_sdlb_group_get_last(sparx5, group);
}

static int sparx5_sdlb_group_get_adjacent(struct sparx5 *sparx5, u32 group,
					  u32 idx, u32 *prev, u32 *next,
					  u32 *first)
{
	u32 itr;

	*first = sparx5_sdlb_group_get_first(sparx5, group);
	*prev = *first;
	*next = *first;
	itr = *first;

	for (;;) {
		*next = sparx5_sdlb_group_get_next(sparx5, group, itr);

		if (itr == idx)
			return 0; /* Found it */

		if (itr == *next)
			return -EINVAL; /* Was not found */

		*prev = itr;
		itr = *next;
	}
}

static int sparx5_sdlb_group_get_count(struct sparx5 *sparx5, u32 group)
{
	u32 itr, next;
	int count = 0;

	itr = sparx5_sdlb_group_get_first(sparx5, group);

	for (;;) {
		next = sparx5_sdlb_group_get_next(sparx5, group, itr);
		if (itr == next)
			return count;

		itr = next;
		count++;
	}
}

int sparx5_sdlb_group_get_by_rate(struct sparx5 *sparx5, u32 rate, u32 burst)
{
	const struct sparx5_sdlb_group *group;
	u64 rate_bps;
	int i, count;

	rate_bps = rate * 1000;

	for (i = SPX5_SDLB_GROUP_CNT - 1; i >= 0; i--) {
		group = &sdlb_groups[i];

		count = sparx5_sdlb_group_get_count(sparx5, i);

		/* Check that this group is not full.
		 * According to LB group configuration rules: the number of XLBs
		 * in a group must not exceed PUP_INTERVAL/4 - 1.
		 */
		if (count > ((group->pup_interval / 4) - 1))
			continue;

		if (rate_bps < group->max_rate)
			return i;
	}

	return -ENOSPC;
}

int sparx5_sdlb_group_get_by_index(struct sparx5 *sparx5, u32 idx, u32 *group)
{
	u32 itr, next;
	int i;

	for (i = 0; i < SPX5_SDLB_GROUP_CNT; i++) {
		if (sparx5_sdlb_group_is_empty(sparx5, i))
			continue;

		itr = sparx5_sdlb_group_get_first(sparx5, i);

		for (;;) {
			next = sparx5_sdlb_group_get_next(sparx5, i, itr);

			if (itr == idx) {
				*group = i;
				return 0; /* Found it */
			}
			if (itr == next)
				break; /* Was not found */

			itr = next;
		}
	}

	return -EINVAL;
}

static int sparx5_sdlb_group_link(struct sparx5 *sparx5, u32 group, u32 idx,
				  u32 first, u32 next, bool empty)
{
	/* Stop leaking */
	sparx5_sdlb_group_disable(sparx5, group);

	if (empty)
		return 0;

	/* Link insertion lb to next lb */
	spx5_wr(ANA_AC_SDLB_XLB_NEXT_LBSET_NEXT_SET(next) |
			ANA_AC_SDLB_XLB_NEXT_LBGRP_SET(group),
		sparx5, ANA_AC_SDLB_XLB_NEXT(idx));

	/* Set the first lb */
	spx5_wr(ANA_AC_SDLB_XLB_START_LBSET_START_SET(first), sparx5,
		ANA_AC_SDLB_XLB_START(group));

	/* Start leaking */
	sparx5_sdlb_group_enable(sparx5, group);

	return 0;
};

int sparx5_sdlb_group_add(struct sparx5 *sparx5, u32 group, u32 idx)
{
	u32 first, next;

	/* We always add to head of the list */
	first = idx;

	if (sparx5_sdlb_group_is_empty(sparx5, group))
		next = idx;
	else
		next = sparx5_sdlb_group_get_first(sparx5, group);

	return sparx5_sdlb_group_link(sparx5, group, idx, first, next, false);
}

int sparx5_sdlb_group_del(struct sparx5 *sparx5, u32 group, u32 idx)
{
	u32 first, next, prev;
	bool empty = false;

	if (sparx5_sdlb_group_get_adjacent(sparx5, group, idx, &prev, &next,
					   &first) < 0) {
		pr_err("%s:%d Could not find idx: %d in group: %d", __func__,
		       __LINE__, idx, group);
		return -EINVAL;
	}

	if (sparx5_sdlb_group_is_singular(sparx5, group)) {
		empty = true;
	} else if (sparx5_sdlb_group_is_last(sparx5, group, idx)) {
		/* idx is removed, prev is now last */
		idx = prev;
		next = prev;
	} else if (sparx5_sdlb_group_is_first(sparx5, group, idx)) {
		/* idx is removed and points to itself, first is next */
		first = next;
		next = idx;
	} else {
		/* Next is not touched */
		idx = prev;
	}

	return sparx5_sdlb_group_link(sparx5, group, idx, first, next, empty);
}

void sparx5_sdlb_group_init(struct sparx5 *sparx5, u64 max_rate, u32 min_burst,
			    u32 frame_size, u32 idx)
{
	u32 thres_shift, mask = 0x01, power = 0;
	struct sparx5_sdlb_group *group;
	u64 max_token;

	group = &sdlb_groups[idx];

	/* Number of positions to right-shift LB's threshold value. */
	while ((min_burst & mask) == 0) {
		power++;
		mask <<= 1;
	}
	thres_shift = SPX5_SDLB_2CYCLES_TYPE2_THRES_OFFSET - power;

	max_token = (min_burst > SPX5_SDLB_PUP_TOKEN_MAX) ?
			    SPX5_SDLB_PUP_TOKEN_MAX :
			    min_burst;
	group->pup_interval =
		sparx5_sdlb_pup_interval_get(sparx5, max_token, max_rate);

	group->frame_size = frame_size;

	spx5_wr(ANA_AC_SDLB_PUP_INTERVAL_PUP_INTERVAL_SET(group->pup_interval),
		sparx5, ANA_AC_SDLB_PUP_INTERVAL(idx));

	spx5_wr(ANA_AC_SDLB_FRM_RATE_TOKENS_FRM_RATE_TOKENS_SET(frame_size),
		sparx5, ANA_AC_SDLB_FRM_RATE_TOKENS(idx));

	spx5_wr(ANA_AC_SDLB_LBGRP_MISC_THRES_SHIFT_SET(thres_shift), sparx5,
		ANA_AC_SDLB_LBGRP_MISC(idx));
}