/*
   <:copyright-BRCM:2015:DUAL/GPL:standard
   
      Copyright (c) 2015 Broadcom 
      All Rights Reserved
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2, as published by
   the Free Software Foundation (the "GPL").
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   
   A copy of the GPL is available at http://www.broadcom.com/licenses/GPLv2.php, or by
   writing to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.
   
   :>
 */

/*
 *  Created on: Apr/2017
 *      Author: ido.brezel@broadcom.com
 */

#include "mux_index.h"

static int mux_set_index(char *sw_name, enetx_port_t ***map, int *count, int index, enetx_port_t *port)
{
    int old_count = *count;

    if (!port)
    {
        if (index >= old_count)
            return -1;
    }
    else if (index >= old_count)
    {
        enetx_port_t **ports = krealloc(*map, sizeof(void *)*(index + 1), GFP_KERNEL);
        if (!ports)
        {
            enet_err("cannot de/mux %s: %s:%d not enough memory\n", port->obj_name, sw_name, index);
            return -ENOMEM;
        }

        memset(&(ports[old_count]), 0, sizeof(void *)*(index - old_count));
        *count = index + 1;
        *map = ports;
    }
    else if ((*map)[index])
    {
        enet_err("cannot de/mux %s: %s:%d already taken by %s\n", port->obj_name, sw_name, index, ((*map)[index])->obj_name);
        return -EBUSY;
    }

    rcu_assign_pointer((*map)[index], port);
    
    return 0;
}

/* demux port on switch */
int mux_set_rx_index(enetx_port_t *sw, int index, enetx_port_t *port)
{
    int rc;

    if (!(rc = mux_set_index(sw->obj_name, &sw->s.demux_map, &sw->s.demux_count, index, port)))
    {
        if (!port)
        {
            enet_dbg("demux clear: %s:%d\n", sw->obj_name, index);
            return 0;
        }

        enet_dbg("demux %s: %s:%d\n", port->obj_name, sw->obj_name, index);
    }

    return rc;
}

/* mux port on switch */
/* Usually for non-root_sw, should call mux_set_tx_index with port->p.port_id for muxing */
int mux_set_tx_index(enetx_port_t *from, enetx_port_t *sw, int index, enetx_port_t *to)
{
    int rc;

    if (!(rc = mux_set_index(sw->obj_name, &sw->s.mux_map, &sw->s.mux_count, index, to)))
    {
        if (!to)
        {
            enet_dbg("mux clear %s -> NULL: %s:%d\n", from->obj_name, sw->obj_name, index);
            return 0;
        }

        /* Cache mux OP in port object */
        from->p.mux_port_tx = sw->s.ops->mux_port_tx;
        enet_dbg("mux %s -> %s: %s:%d\n", from->obj_name, to->obj_name, sw->obj_name, index);
    }

    return rc;
}

/* This function must be called under rcu_read_lock() */
int mux_get_rx_index(enetx_port_t *sw, enetx_rx_info_t *rx_info, FkBuff_t *fkb, enetx_port_t **out_port)
{
    if (unlikely(rx_info->src_port >= sw->s.demux_count))
    {
        *out_port = NULL;
        return -1;
    }

    *out_port = rcu_dereference(sw->s.demux_map[rx_info->src_port]);
    enet_dbg_rx("demux rx_port %d tx_port %d sw: %s port: %px\n", rx_info->src_port, *out_port ? (*out_port)->p.port_id : -1, sw->obj_name, sw->s.demux_map[rx_info->src_port]);
    
#ifdef NEXT_LEVEL_DEMUX_REQUIRED
    if (unlikely(!*out_port))
        return -1;

    {
        enetx_rx_info_t rx_info2 = { .src_port = (*out_port)->p.port_id };

        sw = (*out_port)->p.child_sw;
        if (sw && sw->s.ops->mux_port_rx)
            return sw->s.ops->mux_port_rx(sw, &rx_info2, fkb, out_port);
    }
#endif

    return 0;
}

/* This function must be called under rcu_read_lock() */
int mux_get_tx_index(enetx_port_t *tx_port, pNBuff_t pNBuff, enetx_port_t **out_port)
{
    enetx_port_t *sw = tx_port->p.parent_sw;
    *out_port = rcu_dereference(sw->s.mux_map[tx_port->p.port_id]);

    enet_dbg_tx("muxed %s on %s:%d to %s\n", tx_port->obj_name, sw->obj_name, tx_port->p.port_id, (*out_port) ? (*out_port)->obj_name : "error");
    
    if (unlikely(!(*out_port)))
        return -1;

    return 0;
}

void mux_index_sw_free(enetx_port_t *sw)
{
    kfree(sw->s.demux_map);
    sw->s.demux_map = NULL;
    kfree(sw->s.mux_map);
    sw->s.mux_map = NULL;
}