net_mac.c

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/************************************************************************
 *
 *      net_mac.c
 *
 *      The 'NET_MAC' module implements the MAC-layer services to provide
 *      service access points, which are linked with the 'type'-field
 *      of the MAC-header.
 *
 * ######################################################################
 *
 * mips_start_of_legal_notice
 * 
 * Copyright (c) 2004 MIPS Technologies, Inc. All rights reserved.
 *
 *
 * Unpublished rights (if any) reserved under the copyright laws of the
 * United States of America and other countries.
 *
 * This code is proprietary to MIPS Technologies, Inc. ("MIPS
 * Technologies"). Any copying, reproducing, modifying or use of this code
 * (in whole or in part) that is not expressly permitted in writing by MIPS
 * Technologies or an authorized third party is strictly prohibited. At a
 * minimum, this code is protected under unfair competition and copyright
 * laws. Violations thereof may result in criminal penalties and fines.
 *
 * MIPS Technologies reserves the right to change this code to improve
 * function, design or otherwise. MIPS Technologies does not assume any
 * liability arising out of the application or use of this code, or of any
 * error or omission in such code. Any warranties, whether express,
 * statutory, implied or otherwise, including but not limited to the implied
 * warranties of merchantability or fitness for a particular purpose, are
 * excluded. Except as expressly provided in any written license agreement
 * from MIPS Technologies or an authorized third party, the furnishing of
 * this code does not give recipient any license to any intellectual
 * property rights, including any patent rights, that cover this code.
 *
 * This code shall not be exported, reexported, transferred, or released,
 * directly or indirectly, in violation of the law of any country or
 * international law, regulation, treaty, Executive Order, statute,
 * amendments or supplements thereto. Should a conflict arise regarding the
 * export, reexport, transfer, or release of this code, the laws of the
 * United States of America shall be the governing law.
 *
 * This code constitutes one or more of the following: commercial computer
 * software, commercial computer software documentation or other commercial
 * items. If the user of this code, or any related documentation of any
 * kind, including related technical data or manuals, is an agency,
 * department, or other entity of the United States government
 * ("Government"), the use, duplication, reproduction, release,
 * modification, disclosure, or transfer of this code, or any related
 * documentation of any kind, is restricted in accordance with Federal
 * Acquisition Regulation 12.212 for civilian agencies and Defense Federal
 * Acquisition Regulation Supplement 227.7202 for military agencies. The use
 * of this code by the Government is further restricted in accordance with
 * the terms of the license agreement(s) and/or applicable contract terms
 * and conditions covering this code from MIPS Technologies or an authorized
 * third party.
 *
 *
 *
 * 
 * mips_end_of_legal_notice
 * 
 *
 ************************************************************************/


/************************************************************************
 *      Include files
 ************************************************************************/

#include <string.h>
#include <stdio.h>
#include <sysdefs.h>
#include <syserror.h>
#include <sysdev.h>
#include <syscon_api.h>

/* net stuff */
#include <net_api.h>
#include "net.h"
#include "net_mac.h"

/* generic device driver interface */
#include <io_api.h>

/* drivers */
#include <lan_api.h>

/************************************************************************
 *      Definitions
 ************************************************************************/

#define MAC_BUFFER_SIZE      0x600 
#define MAC_CACHE_LINE_SIZE  0x20


/************************************************************************
 *      Public variables
 ************************************************************************/

/* MAC undefined address */
t_mac_addr mac_undefined_adr = { 0, 0, 0, 0, 0, 0 } ;

/* MAC broadcast address */
t_mac_addr mac_broadcast_adr = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff } ;

/* Our stations MAC-address */
t_mac_addr mac_station_adr ;


/************************************************************************
 *      Static variables
 ************************************************************************/

/* Global state of MAC */
static UINT32 NET_MAC_state = MAC_STATE_CLOSED ;

/* SAP table */
static t_mac_sap_context sap_context[MAC_SAP_COUNT] ;

/* Major device number of EN0 */
static UINT32 en0_major_device = 0 ;

/* Ref. for loopback buffer */
static void *lbbuf ;

/************************************************************************
 *      Static function prototypes
 ************************************************************************/


/************************************************************************
 *
 *                          NET_MAC_receive
 *  Description :
 *  -------------
 *  In "RX-frame receive int. mode", this function is called from 
 *  the LAN-driver ISR, whenever it receives an Ethernet frame. 
 *
 *  In "RX-frame receive polled mode", this function will still
 *  be called from the LAN-driver, but in this case, the call
 *  gets started when NET_MAC_poll() calls the LAN-driver 'read'
 *  entry.
 *
 *  It must check for any SAP's registered to handle the addressed
 *  SAP and if one found, the registered receive handler is called.
 *
 *
 *
 *  Parameters :
 *  ------------
 *  'length':  length of received ethernet frame
 *  'data':    pointer for received ethernet frame (in driver's space)
 *
 *
 *  Return values :
 *  ---------------
 *  'OK' 
 *
 ************************************************************************/
static
UINT32 NET_MAC_receive( UINT32 length,
                        UINT8  *data    ) ;


/************************************************************************
 *
 *                          NET_MAC_alloc_sap
 *  Description :
 *  -------------
 *  Allocate a MAC SAP, register user context and return a sp-handle.
 * 
 *
 *  Parameters :
 *  ------------
 *
 *  'mac_sap_id',          IN,    value of MAC-'type' to bind for
 *  'mac_usr_receive',     IN,    user-receive function to be registered
 *  'mac_sp_hd',           OUT,   handle of MAC to be used by user by call
 *                                of 'send'
 *
 *
 *  Return values :
 *  ---------------
 * 'ERROR_NET_MAC_NO_FREE_SAP', No SAP entry could be allocated
 * 'OK' = 0x00: 
 *
 *
 ************************************************************************/
static
UINT32 NET_MAC_alloc_sap(  
                      UINT16            mac_sap_id,      /* 'type'-field of mac-header
                                                            always in 'cpu' format          */
                      t_mac_usr_receive mac_usr_receive, /* user defined receive handler    */ 
                      UINT32            *mac_sp_hd ) ;   /* service provider defined handle */

/************************************************************************
 *      Implementation : Public functions
 ************************************************************************/

/************************************************************************
 *
 *                          NET_MAC_init
 *  Description :
 *  -------------
 *  Initialize the MAC module.
 *
 *
 *
 *
 *  Parameters :
 *  ------------
 *  -
 *
 *
 *  Return values :
 *  ---------------
 *  'OK'(=0), successfull initialization
 *
 ************************************************************************/
UINT32 NET_MAC_init(  void )
{
    t_sys_malloc  mem ;
    UINT32        rcode ;
    int           i ;

    /* initialize MAC SAP table */
    for ( i = 0; i <MAC_SAP_COUNT ; i++)
    {
        sap_context[i].mac_sap_state   = MAC_SAP_STATE_CLOSED ;
        sap_context[i].mac_sap         = MAC_SAP_UNDEFINED ;
        sap_context[i].mac_usr_receive = NULL ;
    }

    /* get a local copy of this stations MAC address */
    IF_ERROR( (rcode),
              (SYSCON_read( SYSCON_COM_EN0_MAC_ADDR_ID,
                            &(mac_station_adr),
                            sizeof(mac_station_adr)) ) )

    /* get a EN0 major device number */
    IF_ERROR( (rcode),
              (SYSCON_read( SYSCON_COM_EN0_MAJOR_DEVICE_ID,
                            &(en0_major_device),
                            sizeof(en0_major_device)) ) )

    /* allocate data for loopback buffer */
    mem.size     = MAC_BUFFER_SIZE ;
    mem.boundary = MAC_CACHE_LINE_SIZE ;
    mem.memory   = &(lbbuf) ;
    rcode = SYSCON_read( SYSCON_BOARD_MALLOC_ID,
                             &mem,
                             sizeof(t_sys_malloc) ) ;
    if (rcode != OK)
    {
            return( rcode ) ;
    }
    lbbuf = (void*) KSEG0( (UINT32)lbbuf ) ;

    /* MAC-module has now been initialized */
    NET_MAC_state = MAC_STATE_INITED ;

    return(OK) ;
}


/************************************************************************
 *
 *                          NET_MAC_open
 *  Description :
 *  -------------
 *  Allocate a MAC-SAP and register user context.
 *
 *
 *  Parameters :
 *  ------------
 *  'mac_sap_id',          IN,    value of MAC-'type' to bind for 
 *  'mac_usr_receive',     IN,    user-receive function to be registered 
 *  'mac_sp_hd',           OUT,   handle of MAC to be used by user by call
 *                                of 'send'
 *
 *  Return values :
 *  ---------------
 *  'ERROR_NET_MAC_FATAL_STATE'      A fatal state has been detected in MAC.
 *  'ERROR_NET_MAC_NOT_INITIALIZED'  MAC-'init' has not been called.
 *  'OK'(=0), 
 *
 *
 ************************************************************************/
UINT32 NET_MAC_open(  UINT16            mac_sap_id,      /* 'type'-field of mac-header
                                                            always in 'cpu' format          */
                      t_mac_usr_receive mac_usr_receive, /* user defined receive handler    */ 
                      UINT32            *mac_sp_hd )     /* service provider defined handle */
{
    t_LAN_OPEN_desc desc ;
    UINT32          rcode = OK ;

    switch (NET_MAC_state)
    {
        case MAC_STATE_CLOSED:
                rcode = ERROR_NET_MAC_NOT_INITIALIZED ;
            break;

        case MAC_STATE_INITED:
                /* try allocating a SAP */
                rcode = NET_MAC_alloc_sap( mac_sap_id,
                                           mac_usr_receive,
                                           mac_sp_hd ) ;
                if ( rcode == OK ) 
                {
                    /* By first 'open', we need to open driver */
                    desc.receive = NET_MAC_receive ;
                    rcode = IO_open( en0_major_device, 0, &desc )  ;
                    if ( rcode == OK )
                    {
                        NET_MAC_state = MAC_STATE_OPEN ;
                    }
                }
            break;

        case MAC_STATE_OPEN:
                /* try allocating a SAP */
                rcode = NET_MAC_alloc_sap( mac_sap_id,
                                           mac_usr_receive,
                                           mac_sp_hd ) ;
            break;

        default:
                /* we should never arrive here */
                rcode = ERROR_NET_MAC_FATAL_STATE ;