drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads_termtbl.c

// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
// Copyright (c) 2019 Mellanox Technologies.

#include <linux/mlx5/fs.h>
#include "eswitch.h"

struct mlx5_termtbl_handle {
	struct hlist_node termtbl_hlist;

	struct mlx5_flow_table *termtbl;
	struct mlx5_flow_act flow_act;
	struct mlx5_flow_destination dest;

	struct mlx5_flow_handle *rule;
	int ref_count;
};

static u32
mlx5_eswitch_termtbl_hash(struct mlx5_flow_act *flow_act,
			  struct mlx5_flow_destination *dest)
{
	u32 hash;

	hash = jhash_1word(flow_act->action, 0);
	hash = jhash((const void *)&flow_act->vlan,
		     sizeof(flow_act->vlan), hash);
	hash = jhash((const void *)&dest->vport.num,
		     sizeof(dest->vport.num), hash);
	hash = jhash((const void *)&dest->vport.vhca_id,
		     sizeof(dest->vport.num), hash);
	return hash;
}

static int
mlx5_eswitch_termtbl_cmp(struct mlx5_flow_act *flow_act1,
			 struct mlx5_flow_destination *dest1,
			 struct mlx5_flow_act *flow_act2,
			 struct mlx5_flow_destination *dest2)
{
	return flow_act1->action != flow_act2->action ||
	       dest1->vport.num != dest2->vport.num ||
	       dest1->vport.vhca_id != dest2->vport.vhca_id ||
	       memcmp(&flow_act1->vlan, &flow_act2->vlan,
		      sizeof(flow_act1->vlan));
}

static int
mlx5_eswitch_termtbl_create(struct mlx5_core_dev *dev,
			    struct mlx5_termtbl_handle *tt,
			    struct mlx5_flow_act *flow_act)
{
	static const struct mlx5_flow_spec spec = {};
	struct mlx5_flow_table_attr ft_attr = {};
	struct mlx5_flow_namespace *root_ns;
	int err;

	root_ns = mlx5_get_flow_namespace(dev, MLX5_FLOW_NAMESPACE_FDB);
	if (!root_ns) {
		esw_warn(dev, "Failed to get FDB flow namespace\n");
		return -EOPNOTSUPP;
	}

	/* As this is the terminating action then the termination table is the
	 * same prio as the slow path
	 */
	ft_attr.flags = MLX5_FLOW_TABLE_TERMINATION;
	ft_attr.prio = FDB_SLOW_PATH;
	ft_attr.max_fte = 1;
	ft_attr.autogroup.max_num_groups = 1;
	tt->termtbl = mlx5_create_auto_grouped_flow_table(root_ns, &ft_attr);
	if (IS_ERR(tt->termtbl)) {
		esw_warn(dev, "Failed to create termination table\n");
		return -EOPNOTSUPP;
	}

	tt->rule = mlx5_add_flow_rules(tt->termtbl, &spec, flow_act,
				       &tt->dest, 1);

	if (IS_ERR(tt->rule)) {
		esw_warn(dev, "Failed to create termination table rule\n");
		goto add_flow_err;
	}
	return 0;

add_flow_err:
	err = mlx5_destroy_flow_table(tt->termtbl);
	if (err)
		esw_warn(dev, "Failed to destroy termination table\n");

	return -EOPNOTSUPP;
}

static struct mlx5_termtbl_handle *
mlx5_eswitch_termtbl_get_create(struct mlx5_eswitch *esw,
				struct mlx5_flow_act *flow_act,
				struct mlx5_flow_destination *dest)
{
	struct mlx5_termtbl_handle *tt;
	bool found = false;
	u32 hash_key;
	int err;

	mutex_lock(&esw->offloads.termtbl_mutex);

	hash_key = mlx5_eswitch_termtbl_hash(flow_act, dest);
	hash_for_each_possible(esw->offloads.termtbl_tbl, tt,
			       termtbl_hlist, hash_key) {
		if (!mlx5_eswitch_termtbl_cmp(&tt->flow_act, &tt->dest,
					      flow_act, dest)) {
			found = true;
			break;
		}
	}
	if (found)
		goto tt_add_ref;

	tt = kzalloc(sizeof(*tt), GFP_KERNEL);
	if (!tt) {
		err = -ENOMEM;
		goto tt_create_err;
	}

	tt->dest.type = MLX5_FLOW_DESTINATION_TYPE_VPORT;
	tt->dest.vport.num = dest->vport.num;
	tt->dest.vport.vhca_id = dest->vport.vhca_id;
	memcpy(&tt->flow_act, flow_act, sizeof(*flow_act));

	err = mlx5_eswitch_termtbl_create(esw->dev, tt, flow_act);
	if (err) {
		esw_warn(esw->dev, "Failed to create termination table\n");
		goto tt_create_err;
	}
	hash_add(esw->offloads.termtbl_tbl, &tt->termtbl_hlist, hash_key);
tt_add_ref:
	tt->ref_count++;
	mutex_unlock(&esw->offloads.termtbl_mutex);
	return tt;
tt_create_err:
	kfree(tt);
	mutex_unlock(&esw->offloads.termtbl_mutex);
	return ERR_PTR(err);
}

void
mlx5_eswitch_termtbl_put(struct mlx5_eswitch *esw,
			 struct mlx5_termtbl_handle *tt)
{
	mutex_lock(&esw->offloads.termtbl_mutex);
	if (--tt->ref_count == 0)
		hash_del(&tt->termtbl_hlist);
	mutex_unlock(&esw->offloads.termtbl_mutex);

	if (!tt->ref_count) {
		mlx5_del_flow_rules(tt->rule);
		mlx5_destroy_flow_table(tt->termtbl);
		kfree(tt);
	}
}

static void
mlx5_eswitch_termtbl_actions_move(struct mlx5_flow_act *src,
				  struct mlx5_flow_act *dst)
{
	if (!(src->action & MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH))
		return;

	src->action &= ~MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH;
	dst->action |= MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH;
	memcpy(&dst->vlan[0], &src->vlan[0], sizeof(src->vlan[0]));
	memset(&src->vlan[0], 0, sizeof(src->vlan[0]));

	if (!(src->action & MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH_2))
		return;

	src->action &= ~MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH_2;
	dst->action |= MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH_2;
	memcpy(&dst->vlan[1], &src->vlan[1], sizeof(src->vlan[1]));
	memset(&src->vlan[1], 0, sizeof(src->vlan[1]));
}

static bool mlx5_eswitch_offload_is_uplink_port(const struct mlx5_eswitch *esw,
						const struct mlx5_flow_spec *spec)
{
	u32 port_mask, port_value;

	if (MLX5_CAP_ESW_FLOWTABLE(esw->dev, flow_source))
		return spec->flow_context.flow_source ==
					MLX5_FLOW_CONTEXT_FLOW_SOURCE_UPLINK;

	port_mask = MLX5_GET(fte_match_param, spec->match_criteria,
			     misc_parameters.source_port);
	port_value = MLX5_GET(fte_match_param, spec->match_value,
			      misc_parameters.source_port);
	return (port_mask & port_value & 0xffff) == MLX5_VPORT_UPLINK;
}

bool
mlx5_eswitch_termtbl_required(struct mlx5_eswitch *esw,
			      struct mlx5_flow_act *flow_act,
			      struct mlx5_flow_spec *spec)
{
	if (!MLX5_CAP_ESW_FLOWTABLE_FDB(esw->dev, termination_table))
		return false;

	/* push vlan on RX */
	return (flow_act->action & MLX5_FLOW_CONTEXT_ACTION_VLAN_PUSH) &&
		mlx5_eswitch_offload_is_uplink_port(esw, spec);
}

struct mlx5_flow_handle *
mlx5_eswitch_add_termtbl_rule(struct mlx5_eswitch *esw,
			      struct mlx5_flow_table *fdb,
			      struct mlx5_flow_spec *spec,
			      struct mlx5_esw_flow_attr *attr,
			      struct mlx5_flow_act *flow_act,
			      struct mlx5_flow_destination *dest,
			      int num_dest)
{
	struct mlx5_flow_act term_tbl_act = {};
	struct mlx5_flow_handle *rule = NULL;
	bool term_table_created = false;
	int num_vport_dests = 0;
	int i, curr_dest;

	mlx5_eswitch_termtbl_actions_move(flow_act, &term_tbl_act);
	term_tbl_act.action |= MLX5_FLOW_CONTEXT_ACTION_FWD_DEST;

	for (i = 0; i < num_dest; i++) {
		struct mlx5_termtbl_handle *tt;

		/* only vport destinations can be terminated */
		if (dest[i].type != MLX5_FLOW_DESTINATION_TYPE_VPORT)
			continue;

		/* get the terminating table for the action list */
		tt = mlx5_eswitch_termtbl_get_create(esw, &term_tbl_act,
						     &dest[i]);
		if (IS_ERR(tt)) {
			esw_warn(esw->dev, "Failed to create termination table\n");
			goto revert_changes;
		}
		attr->dests[num_vport_dests].termtbl = tt;
		num_vport_dests++;

		/* link the destination with the termination table */
		dest[i].type = MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE;
		dest[i].ft = tt->termtbl;
		term_table_created = true;
	}

	/* at least one destination should reference a termination table */
	if (!term_table_created)
		goto revert_changes;

	/* create the FTE */
	rule = mlx5_add_flow_rules(fdb, spec, flow_act, dest, num_dest);
	if (IS_ERR(rule))
		goto revert_changes;

	goto out;

revert_changes:
	/* revert the changes that were made to the original flow_act
	 * and fall-back to the original rule actions
	 */
	mlx5_eswitch_termtbl_actions_move(&term_tbl_act, flow_act);

	for (curr_dest = 0; curr_dest < num_vport_dests; curr_dest++) {
		struct mlx5_termtbl_handle *tt = attr->dests[curr_dest].termtbl;

		/* search for the destination associated with the
		 * current term table
		 */
		for (i = 0; i < num_dest; i++) {
			if (dest[i].ft != tt->termtbl)
				continue;

			memset(&dest[i], 0, sizeof(dest[i]));
			dest[i].type = MLX5_FLOW_DESTINATION_TYPE_VPORT;
			dest[i].vport.num = tt->dest.vport.num;
			dest[i].vport.vhca_id = tt->dest.vport.vhca_id;
			mlx5_eswitch_termtbl_put(esw, tt);
			break;
		}
	}
	rule = mlx5_add_flow_rules(fdb, spec, flow_act, dest, num_dest);
out:
	return rule;
}