/*
 * Copyright (C) 2017 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/bitfield.h>
#include <net/pkt_cls.h>
#include <net/switchdev.h>
#include <net/tc_act/tc_gact.h>
#include <net/tc_act/tc_mirred.h>
#include <net/tc_act/tc_vlan.h>

#include "cmsg.h"
#include "main.h"
#include "../nfp_net_repr.h"

static void nfp_fl_pop_vlan(struct nfp_fl_pop_vlan *pop_vlan)
{
	size_t act_size = sizeof(struct nfp_fl_pop_vlan);
	u16 tmp_pop_vlan_op;

	tmp_pop_vlan_op =
		FIELD_PREP(NFP_FL_ACT_LEN_LW, act_size >> NFP_FL_LW_SIZ) |
		FIELD_PREP(NFP_FL_ACT_JMP_ID, NFP_FL_ACTION_OPCODE_POP_VLAN);

	pop_vlan->a_op = cpu_to_be16(tmp_pop_vlan_op);
	pop_vlan->reserved = 0;
}

static void
nfp_fl_push_vlan(struct nfp_fl_push_vlan *push_vlan,
		 const struct tc_action *action)
{
	size_t act_size = sizeof(struct nfp_fl_push_vlan);
	struct tcf_vlan *vlan = to_vlan(action);
	u16 tmp_push_vlan_tci;
	u16 tmp_push_vlan_op;

	tmp_push_vlan_op =
		FIELD_PREP(NFP_FL_ACT_LEN_LW, act_size >> NFP_FL_LW_SIZ) |
		FIELD_PREP(NFP_FL_ACT_JMP_ID, NFP_FL_ACTION_OPCODE_PUSH_VLAN);

	push_vlan->a_op = cpu_to_be16(tmp_push_vlan_op);
	/* Set action push vlan parameters. */
	push_vlan->reserved = 0;
	push_vlan->vlan_tpid = tcf_vlan_push_proto(action);

	tmp_push_vlan_tci =
		FIELD_PREP(NFP_FL_PUSH_VLAN_PRIO, vlan->tcfv_push_prio) |
		FIELD_PREP(NFP_FL_PUSH_VLAN_VID, vlan->tcfv_push_vid) |
		NFP_FL_PUSH_VLAN_CFI;
	push_vlan->vlan_tci = cpu_to_be16(tmp_push_vlan_tci);
}

static int
nfp_fl_output(struct nfp_fl_output *output, const struct tc_action *action,
	      struct nfp_fl_payload *nfp_flow, bool last,
	      struct net_device *in_dev)
{
	size_t act_size = sizeof(struct nfp_fl_output);
	struct net_device *out_dev;
	u16 tmp_output_op;
	int ifindex;

	/* Set action opcode to output action. */
	tmp_output_op =
		FIELD_PREP(NFP_FL_ACT_LEN_LW, act_size >> NFP_FL_LW_SIZ) |
		FIELD_PREP(NFP_FL_ACT_JMP_ID, NFP_FL_ACTION_OPCODE_OUTPUT);

	output->a_op = cpu_to_be16(tmp_output_op);

	/* Set action output parameters. */
	output->flags = cpu_to_be16(last ? NFP_FL_OUT_FLAGS_LAST : 0);

	ifindex = tcf_mirred_ifindex(action);
	out_dev = __dev_get_by_index(dev_net(in_dev), ifindex);
	if (!out_dev)
		return -EOPNOTSUPP;

	/* Only offload egress ports are on the same device as the ingress
	 * port.
	 */
	if (!switchdev_port_same_parent_id(in_dev, out_dev))
		return -EOPNOTSUPP;

	output->port = cpu_to_be32(nfp_repr_get_port_id(out_dev));
	if (!output->port)
		return -EOPNOTSUPP;

	nfp_flow->meta.shortcut = output->port;

	return 0;
}

static int
nfp_flower_loop_action(const struct tc_action *a,
		       struct nfp_fl_payload *nfp_fl, int *a_len,
		       struct net_device *netdev)
{
	struct nfp_fl_push_vlan *psh_v;
	struct nfp_fl_pop_vlan *pop_v;
	struct nfp_fl_output *output;
	int err;

	if (is_tcf_gact_shot(a)) {
		nfp_fl->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_DROP);
	} else if (is_tcf_mirred_egress_redirect(a)) {
		if (*a_len + sizeof(struct nfp_fl_output) > NFP_FL_MAX_A_SIZ)
			return -EOPNOTSUPP;

		output = (struct nfp_fl_output *)&nfp_fl->action_data[*a_len];
		err = nfp_fl_output(output, a, nfp_fl, true, netdev);
		if (err)
			return err;

		*a_len += sizeof(struct nfp_fl_output);
	} else if (is_tcf_mirred_egress_mirror(a)) {
		if (*a_len + sizeof(struct nfp_fl_output) > NFP_FL_MAX_A_SIZ)
			return -EOPNOTSUPP;

		output = (struct nfp_fl_output *)&nfp_fl->action_data[*a_len];
		err = nfp_fl_output(output, a, nfp_fl, false, netdev);
		if (err)
			return err;

		*a_len += sizeof(struct nfp_fl_output);
	} else if (is_tcf_vlan(a) && tcf_vlan_action(a) == TCA_VLAN_ACT_POP) {
		if (*a_len + sizeof(struct nfp_fl_pop_vlan) > NFP_FL_MAX_A_SIZ)
			return -EOPNOTSUPP;

		pop_v = (struct nfp_fl_pop_vlan *)&nfp_fl->action_data[*a_len];
		nfp_fl->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_POPV);

		nfp_fl_pop_vlan(pop_v);
		*a_len += sizeof(struct nfp_fl_pop_vlan);
	} else if (is_tcf_vlan(a) && tcf_vlan_action(a) == TCA_VLAN_ACT_PUSH) {
		if (*a_len + sizeof(struct nfp_fl_push_vlan) > NFP_FL_MAX_A_SIZ)
			return -EOPNOTSUPP;

		psh_v = (struct nfp_fl_push_vlan *)&nfp_fl->action_data[*a_len];
		nfp_fl->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_NULL);

		nfp_fl_push_vlan(psh_v, a);
		*a_len += sizeof(struct nfp_fl_push_vlan);
	} else {
		/* Currently we do not handle any other actions. */
		return -EOPNOTSUPP;
	}

	return 0;
}

int nfp_flower_compile_action(struct tc_cls_flower_offload *flow,
			      struct net_device *netdev,
			      struct nfp_fl_payload *nfp_flow)
{
	int act_len, act_cnt, err;
	const struct tc_action *a;
	LIST_HEAD(actions);

	memset(nfp_flow->action_data, 0, NFP_FL_MAX_A_SIZ);
	nfp_flow->meta.act_len = 0;
	act_len = 0;
	act_cnt = 0;

	tcf_exts_to_list(flow->exts, &actions);
	list_for_each_entry(a, &actions, list) {
		err = nfp_flower_loop_action(a, nfp_flow, &act_len, netdev);
		if (err)
			return err;
		act_cnt++;
	}

	/* We optimise when the action list is small, this can unfortunately
	 * not happen once we have more than one action in the action list.
	 */
	if (act_cnt > 1)
		nfp_flow->meta.shortcut = cpu_to_be32(NFP_FL_SC_ACT_NULL);

	nfp_flow->meta.act_len = act_len;

	return 0;
}