// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/* Copyright (c) 2020 Marvell International Ltd. All rights reserved */

#include <linux/kernel.h>
#include <linux/list.h>

#include "prestera.h"
#include "prestera_acl.h"
#include "prestera_flow.h"
#include "prestera_flower.h"
#include "prestera_matchall.h"
#include "prestera_span.h"

static LIST_HEAD(prestera_block_cb_list);

static int prestera_flow_block_mall_cb(struct prestera_flow_block *block,
                                       struct tc_cls_matchall_offload *f)
{
        switch (f->command) {
        case TC_CLSMATCHALL_REPLACE:
                return prestera_mall_replace(block, f);
        case TC_CLSMATCHALL_DESTROY:
                prestera_mall_destroy(block);
                return 0;
        default:
                return -EOPNOTSUPP;
        }
}

static int prestera_flow_block_flower_cb(struct prestera_flow_block *block,
                                         struct flow_cls_offload *f)
{
        switch (f->command) {
        case FLOW_CLS_REPLACE:
                return prestera_flower_replace(block, f);
        case FLOW_CLS_DESTROY:
                prestera_flower_destroy(block, f);
                return 0;
        case FLOW_CLS_STATS:
                return prestera_flower_stats(block, f);
        case FLOW_CLS_TMPLT_CREATE:
                return prestera_flower_tmplt_create(block, f);
        case FLOW_CLS_TMPLT_DESTROY:
                prestera_flower_tmplt_destroy(block, f);
                return 0;
        default:
                return -EOPNOTSUPP;
        }
}

static int prestera_flow_block_cb(enum tc_setup_type type,
                                  void *type_data, void *cb_priv)
{
        struct prestera_flow_block *block = cb_priv;

        switch (type) {
        case TC_SETUP_CLSFLOWER:
                return prestera_flow_block_flower_cb(block, type_data);
        case TC_SETUP_CLSMATCHALL:
                return prestera_flow_block_mall_cb(block, type_data);
        default:
                return -EOPNOTSUPP;
        }
}

static void prestera_flow_block_destroy(void *cb_priv)
{
        struct prestera_flow_block *block = cb_priv;

        prestera_flower_template_cleanup(block);

        WARN_ON(!list_empty(&block->template_list));
        WARN_ON(!list_empty(&block->binding_list));

        kfree(block);
}

static struct prestera_flow_block *
prestera_flow_block_create(struct prestera_switch *sw,
                           struct net *net,
                           bool ingress)
{
        struct prestera_flow_block *block;

        block = kzalloc_obj(*block);
        if (!block)
                return NULL;

        INIT_LIST_HEAD(&block->binding_list);
        INIT_LIST_HEAD(&block->template_list);
        block->net = net;
        block->sw = sw;
        block->mall.prio_min = UINT_MAX;
        block->mall.prio_max = 0;
        block->mall.bound = false;
        block->ingress = ingress;

        return block;
}

static void prestera_flow_block_release(void *cb_priv)
{
        struct prestera_flow_block *block = cb_priv;

        prestera_flow_block_destroy(block);
}

static bool
prestera_flow_block_is_bound(const struct prestera_flow_block *block)
{
        return block->ruleset_zero;
}

static struct prestera_flow_block_binding *
prestera_flow_block_lookup(struct prestera_flow_block *block,
                           struct prestera_port *port)
{
        struct prestera_flow_block_binding *binding;

        list_for_each_entry(binding, &block->binding_list, list)
                if (binding->port == port)
                        return binding;

        return NULL;
}

static int prestera_flow_block_bind(struct prestera_flow_block *block,
                                    struct prestera_port *port)
{
        struct prestera_flow_block_binding *binding;
        int err;

        binding = kzalloc_obj(*binding);
        if (!binding)
                return -ENOMEM;

        binding->span_id = PRESTERA_SPAN_INVALID_ID;
        binding->port = port;

        if (prestera_flow_block_is_bound(block)) {
                err = prestera_acl_ruleset_bind(block->ruleset_zero, port);
                if (err)
                        goto err_ruleset_bind;
        }

        list_add(&binding->list, &block->binding_list);
        return 0;

err_ruleset_bind:
        kfree(binding);
        return err;
}

static int prestera_flow_block_unbind(struct prestera_flow_block *block,
                                      struct prestera_port *port)
{
        struct prestera_flow_block_binding *binding;

        binding = prestera_flow_block_lookup(block, port);
        if (!binding)
                return -ENOENT;

        list_del(&binding->list);

        if (prestera_flow_block_is_bound(block))
                prestera_acl_ruleset_unbind(block->ruleset_zero, port);

        kfree(binding);
        return 0;
}

static struct prestera_flow_block *
prestera_flow_block_get(struct prestera_switch *sw,
                        struct flow_block_offload *f,
                        bool *register_block,
                        bool ingress)
{
        struct prestera_flow_block *block;
        struct flow_block_cb *block_cb;

        block_cb = flow_block_cb_lookup(f->block,
                                        prestera_flow_block_cb, sw);
        if (!block_cb) {
                block = prestera_flow_block_create(sw, f->net, ingress);
                if (!block)
                        return ERR_PTR(-ENOMEM);

                block_cb = flow_block_cb_alloc(prestera_flow_block_cb,
                                               sw, block,
                                               prestera_flow_block_release);
                if (IS_ERR(block_cb)) {
                        prestera_flow_block_destroy(block);
                        return ERR_CAST(block_cb);
                }

                block->block_cb = block_cb;
                *register_block = true;
        } else {
                block = flow_block_cb_priv(block_cb);
                *register_block = false;
        }

        flow_block_cb_incref(block_cb);

        return block;
}

static void prestera_flow_block_put(struct prestera_flow_block *block)
{
        struct flow_block_cb *block_cb = block->block_cb;

        if (flow_block_cb_decref(block_cb))
                return;

        flow_block_cb_free(block_cb);
        prestera_flow_block_destroy(block);
}

static int prestera_setup_flow_block_bind(struct prestera_port *port,
                                          struct flow_block_offload *f, bool ingress)
{
        struct prestera_switch *sw = port->sw;
        struct prestera_flow_block *block;
        struct flow_block_cb *block_cb;
        bool register_block;
        int err;

        block = prestera_flow_block_get(sw, f, &register_block, ingress);
        if (IS_ERR(block))
                return PTR_ERR(block);

        block_cb = block->block_cb;

        err = prestera_flow_block_bind(block, port);
        if (err)
                goto err_block_bind;

        if (register_block) {
                flow_block_cb_add(block_cb, f);
                list_add_tail(&block_cb->driver_list, &prestera_block_cb_list);
        }

        if (ingress)
                port->ingress_flow_block = block;
        else
                port->egress_flow_block = block;

        return 0;

err_block_bind:
        prestera_flow_block_put(block);

        return err;
}

static void prestera_setup_flow_block_unbind(struct prestera_port *port,
                                             struct flow_block_offload *f, bool ingress)
{
        struct prestera_switch *sw = port->sw;
        struct prestera_flow_block *block;
        struct flow_block_cb *block_cb;
        int err;

        block_cb = flow_block_cb_lookup(f->block, prestera_flow_block_cb, sw);
        if (!block_cb)
                return;

        block = flow_block_cb_priv(block_cb);

        prestera_mall_destroy(block);

        err = prestera_flow_block_unbind(block, port);
        if (err)
                goto error;

        if (!flow_block_cb_decref(block_cb)) {
                flow_block_cb_remove(block_cb, f);
                list_del(&block_cb->driver_list);
        }
error:
        if (ingress)
                port->ingress_flow_block = NULL;
        else
                port->egress_flow_block = NULL;
}

static int prestera_setup_flow_block_clsact(struct prestera_port *port,
                                            struct flow_block_offload *f,
                                            bool ingress)
{
        f->driver_block_list = &prestera_block_cb_list;

        switch (f->command) {
        case FLOW_BLOCK_BIND:
                return prestera_setup_flow_block_bind(port, f, ingress);
        case FLOW_BLOCK_UNBIND:
                prestera_setup_flow_block_unbind(port, f, ingress);
                return 0;
        default:
                return -EOPNOTSUPP;
        }
}

int prestera_flow_block_setup(struct prestera_port *port,
                              struct flow_block_offload *f)
{
        switch (f->binder_type) {
        case FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS:
                return prestera_setup_flow_block_clsact(port, f, true);
        case FLOW_BLOCK_BINDER_TYPE_CLSACT_EGRESS:
                return prestera_setup_flow_block_clsact(port, f, false);
        default:
                return -EOPNOTSUPP;
        }
}