excep.c

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        return OK;
    }
    else
        return ERROR_EXCEP_ILLEGAL_HANDLER;
}


/************************************************************************
 *
 *                          EXCEP_register_cpu_isr
 *  Description :
 *  -------------
 *
 *  Registers an interrupt handler for the specified CPU interrupt.
 *  The highest service priority is attached to HW-INT5, which is
 *  connected to the CPU-built-in CP0-timer. SW_INT0 gets the lowest
 *  service priority. During registration, the interrupt mask field
 *  in the CPU CP0-status register is updated to enable interrupts
 *  from the specified interrupt source.
 *
 *  A special ID is defined :
 *      EXCEP_DEFAULT_HANDLER used for a default handler.
 *	
 *  The default handler is called if no other handler is registered
 *  for a CPU interrupt.
 *
 *  Deregistration of the default handler may be done by calling
 *  this function with 'handler' set to NULL.
 *  Also, a new default handler may be registered even if a 
 *  previously registered handler has not been deregistered.
 *  Handlers for specific CPU interrupts must be deregistered using 
 *  EXCEP_deregister_cpu_isr.
 *
 *  Parameters :
 *  ------------
 *
 *  'cpu_int',      IN,    CPU interrupt (C0_STATUS_IM_HW[0..5] |
 *					  C0_STATUS_IM_SW[0..1])
 *			   or EXCEP_DEFAULT_HANDLER for a default handler.
 *  'handler',      IN,    Function pointer for user defined handler
 *  'data',         IN,    Data pointer, may be NULL
 *  'ref',	    OUT,   Handle used for deregistration of handler.
 *
 *  Return values :
 *  ---------------
 *
 *  'OK'(=0)
 *  'ERROR_EXCEP_ILLEGAL_INTERRUPT': CPU interrupt source is unknown
 *  'ERROR_EXCEP_ILLEGAL_HANDLER':   Handler reference is NULL
 *  'ERROR_EXCEP_NO_SPACE':          Too many handlers have been registered
 *
 ************************************************************************/
INT32 
EXCEP_register_cpu_isr(
    UINT32      cpu_int,	     /* CPU interrupt, 0..7		*/
    t_EXCEP_isr handler,	     /* ISR to be registered		*/
    void        *data,   	     /* Data reference to be registered */
    t_EXCEP_ref *ref )	             /* OUT : Handle for deregistration */
{
    UINT32        old_ie;
    t_INT_handler *h = NULL;
    UINT32        rc = OK;
    UINT32        i;
    bool	  enable = FALSE;

    /* Disable interrupts */
    old_ie = sys_disable_int();

    if( cpu_int == EXCEP_DEFAULT_HANDLER )
    {
        h = &table.default_int;
    }
    else if( cpu_int >= MAX_INTERRUPTS )
    {
        /* Interrupt specified is unknown */
        rc = ERROR_EXCEP_ILLEGAL_INTERRUPT;
    }
    else
    {
        /* Specific interrupt */

        if( handler == NULL )
        {
            rc = ERROR_EXCEP_ILLEGAL_HANDLER;
        }
        else if( table.interrupt[cpu_int].list_size == INT_HANDLERS_PER_LINE )
        {
            /* Too many handlers have been registered */
            rc = ERROR_EXCEP_NO_SPACE;
        }
        else
        {
            /* Find unused entry in array */
            for( i = 0, h = &table.interrupt[cpu_int].int_handler[0];
	         (i < INT_HANDLERS_PER_LINE) && (h->handler != NULL);
	         i++, h++) 
            {
	        ;
	    }
	    
            table.interrupt[cpu_int].list_size++;
	    enable = TRUE;
        }
    }

    if( rc == OK )
    {
        h->handler = handler;	
	h->data    = data;

        if( ref )
            *ref = (t_EXCEP_ref)h;

        /* Enable interrupt mask */
	if( enable )
	{
            sys_enable_int_mask( cpu_int );
	}
    }

    /* Restore interrupt enable status */
    if(old_ie)
        sys_enable_int();

    return rc;
}


/************************************************************************
 *
 *                          EXCEP_deregister_cpu_isr
 *  Description :
 *  -------------
 *
 *  Deregisters interrupt handler. 
 *  It is OK to call this function even if we are in interrupt context.
 *  
 *  Parameters :
 *  ------------
 *
 *  'ref',	 IN,   Handle obtained when calling EXCEP_register_cpu_isr
 *
 *  Return values :
 *  ---------------
 *
 *  'OK'(=0)
 *  'ERROR_EXCEP_ILLEGAL_HANDLER':  ref is unknown
 *
 ************************************************************************/
INT32 
EXCEP_deregister_cpu_isr(
    t_EXCEP_ref ref )	             /* In : Handle for deregistration */
{
    UINT32		      old_ie;
    t_INT_handler             *h = (t_INT_handler *)ref;
    t_EXCEP_int_handler_list  *list;
    INT32		      rc = ERROR_EXCEP_ILLEGAL_HANDLER;
    UINT32		      i, t;

    /* Disable interrupts */
    old_ie = sys_disable_int();

    /* Find and deregister handler pointed to by ref (h) */

    if( h == &table.default_int )
    {
        h->handler = NULL;
	rc	   = OK;
    }
    else
    {
        for( i=0; (i<MAX_INTERRUPTS) && (rc != OK); i++ )
        {
            list = &table.interrupt[ i ];
	
	    for( t=0; (t<INT_HANDLERS_PER_LINE) && (rc != OK); t++ )
	    {
	        if( &list->int_handler[t] == h )
	        {
	            (list->list_size)--;
	  	    h->handler = NULL;

		    if( list->list_size == 0 )
		    {
		        /* Disable interrupt mask */
			sys_disable_int_mask( i );
		    }

		    rc = OK;
	        }
	    }
        }
    }

    /* Restore interrupt enable status */
    if(old_ie)
        sys_enable_int();

    return rc;
}


/************************************************************************
 *
 *                          EXCEP_register_ic_isr
 *  Description :
 *  -------------
 *
 *  Registers an interrupt handler for the specified source in the
 *  interrupt controller. 
 *
 *  A special ID is defined :
 *      EXCEP_DEFAULT_HANDLER used for a default handler.
 *	
 *  The default handler is called if no other handler is registered
 *  for an interrupt.
 *
 *  Deregistration of the default handler may be done by calling
 *  this function with 'handler' set to NULL.
 *  Also, a new default handler may be registered even if a 
 *  previously registered handler has not been deregistered.
 *  Handlers for specific interrupts must be deregistered using 
 *  EXCEP_deregister_ic_isr.

 *  Parameters :
 *  ------------
 *
 *  'ic_int_line', IN,    Interrupt source line in Int. Controller
 *			  or EXCEP_DEFAULT_HANDLER for a default handler.
 *  'handler',     IN,    Function pointer for user defined handler
 *  'data',        IN,    Data pointer; may be NULL
 *  'ref',	   OUT,   Handle used for deregistration of handler.
 *
 *  Return values :
 *  ---------------
 *
 *  'OK'(=0)
 *  'ERROR_EXCEP_ILLEGAL_INTERRUPT': Int. source line is unknown
 *  'ERROR_EXCEP_ILLEGAL_HANDLER':   Handler reference is NULL
 *  'ERROR_EXCEP_NO_SPACE':          Too many handlers have been registered
 *
 ************************************************************************/
INT32 
EXCEP_register_ic_isr(
    UINT32      ic_int_line,	    /* Exception identification		*/
    t_EXCEP_isr handler,	    /* ISR to be registered		*/
    void        *data,		    /* Data reference to be registered  */
    t_EXCEP_ref *ref )		    /* OUT : Handle for deregistration  */
{
    UINT32        old_ie;
    t_INT_handler *h = NULL;
    bool	  enable = FALSE;
    UINT32        rc     = OK;
    int		  i;

    /* Disable interrupts */
    old_ie = sys_disable_int();

    if( ic_int_line == EXCEP_DEFAULT_HANDLER )
    {
        h = &table.default_ctrl;
    }
    else if( ic_int_line >= excep_ic_count )
    {
        /* Interrupt specified is unknown */
	rc = ERROR_EXCEP_ILLEGAL_INTERRUPT;
    }
    else
    {
        /* Specific interrupt */

        if( handler == NULL )
        {
	    rc = ERROR_EXCEP_ILLEGAL_HANDLER;
        }
        else if( table.controller[ic_int_line].list_size == CTRL_HANDLERS_PER_LINE )
        {
            /* Too many handlers have been registered */
            rc = ERROR_EXCEP_NO_SPACE;
        }
        else
        {
            /* Find unused entry in array */
            for( i = 0, h = &table.controller[ic_int_line].ctrl_handler[0];
	         (i < CTRL_HANDLERS_PER_LINE) && (h->handler != NULL);
	         i++, h++) 
            {
	        ;
	    }
	    
            table.controller[ic_int_line].list_size++;
	    enable = TRUE;
        }
    }

    if( rc == OK )
    {
        h->handler = handler;
	h->data    = data;

        if( ref )
            *ref = (t_EXCEP_ref)h;

        /* add this source to enable mask of interrupt controller */
	if( enable )
            arch_excep_enable_int(ic_int_line);
    }
    
    /* Restore interrupt enable status */
    if(old_ie)
        sys_enable_int();

    return rc;
}


/************************************************************************
 *
 *                          EXCEP_deregister_ic_isr
 *  Description :
 *  -------------
 *
 *  Deregisters interrupt handler for source in interrupt controller
 *  It is OK to call this function even if we are in interrupt context.
 *
 *  Parameters :
 *  ------------
 *
 *  'ref',	 IN,   Handle obtained when calling EXCEP_register_ic_isr
 *
 *  Return values :
 *  ---------------
 *
 *  'OK'(=0)
 *  'ERROR_EXCEP_ILLEGAL_HANDLER':  ref is unknown
 *
 ************************************************************************/
INT32 
EXCEP_deregister_ic_isr(
    t_EXCEP_ref ref )	             /* In : Handle for deregistration */
{
    UINT32		      old_ie;
    t_INT_handler             *h = (t_INT_handler *)ref;
    t_EXCEP_ctrl_handler_list *list;
    INT32		      rc = ERROR_EXCEP_ILLEGAL_HANDLER;
    UINT32		      i, t;

    /* Disable interrupts */
    old_ie = sys_disable_int();

    /* Find and deregister handler pointed to by ref (h) */

    if( h == &table.default_ctrl )
    {
        h->handler = NULL;
	rc	   = OK;
    }
    else
    {
        for( i=0; (i<MAX_IC) && (rc != OK); i++ )
        {
            list = &table.controller[ i ];
	
	    for( t=0; (t<CTRL_HANDLERS_PER_LINE) && (rc != OK); t++ )
	    {
	        if( &list->ctrl_handler[t] == h )
	        {
	            (list->list_size)--;
	  	    h->handler = NULL;

		    if( list->list_size == 0 )
		    {
		        /* Disable interrupt mask */
                        arch_excep_disable_int( i );
		    }

		    rc = OK;
	        }
	    }
        }
    }

    /* Restore interrupt enable status */
    if(old_ie)
        sys_enable_int();

    return rc;
}


/************************************************************************
 *
 *                          EXCEP_store_handlers
 *  Description :
 *  -------------
 *
 *  The current setup of registered exception handlers is copied to
 *  a table so that it may later be restored using EXCEP_set_handlers().
 *
 ************************************************************************/
void 
EXCEP_store_handlers(
    UINT32 set ) /* table where setup is copied */
{
    UINT32 old_ie;

    /* Disable interrupts */
    old_ie = sys_disable_int();

    switch( set )
    {
      case EXCEP_HANDLERS_SHELL :
        memcpy( &table_shell, &table, sizeof(t_table) );
	break;
      case EXCEP_HANDLERS_GDB :
        memcpy( &table_gdb,   &table, sizeof(t_table) );
	break;
      default : /* Should not happen */
    }

    /* Restore interrupt enable status */
    if(old_ie)
        sys_enable_int();
}


/************************************************************************
 *
 *                          EXCEP_set_handlers
 *  Description :
 *  -------------
 *
 *  The setup of registered exception handlers is restored to the
 *  state stored previously using EXCEP_store_handlers().
 *
 ************************************************************************/
void 
EXCEP_set_handlers(
    UINT32 set ) /* table where setup is copied */
{
    UINT32 old_ie;

    /* Disable interrupts */
    old_ie = sys_disable_int();

    switch( set )
    {
      case EXCEP_HANDLERS_SHELL :
        memcpy( &table, &table_shell, sizeof(t_table) );
	break;
      case EXCEP_HANDLERS_GDB :
        memcpy( &table, &table_gdb,   sizeof(t_table) );
	break;
      default : /* Should not happen */
    }

    /* Restore interrupt enable status */
    if(old_ie)
        sys_enable_int();
}


/************************************************************************
 *
 *                          EXCEP_print_context
 *  Description :
 *  -------------
 *
 *  Print context
 *
 *  Note : Printout is done by printf() through the IO module, so if
 *         this routine is entered before serial drivers are installed,
 *         no printout will take place - and no harm is done.
 *
 *  Return values :
 *  ---------------
 *
 *  None
 *
 ************************************************************************/
void
EXCEP_print_context( 
    t_gdb_regs *context,	/* Context to print			*/
    char       *msg,		/* Special msg to be printed (or NULL)	*/
    bool       user,		/* In user context			*/
    bool       display )	/* TRUE -> Print EPC in ASCII display	*/
{
    char   *s;
    UINT64 *regs;
    UINT64 reg64;
    UINT32 i,j;
    UINT32 werr;
    UINT32 shadowset;

    if (!context)
	context = EXCEP_get_context_ptr();

    if( msg )
        printf( "\n* %s *\n", msg );
    else	
    {
        printf( "\n* Exception " );
        printf( user ? "(user) : " : ": " );
    }

    if( EXCEP_nmi )
    {
	s = "NMI";
	if( SYSCON_read( SYSCON_BOARD_NMI_WERR_ID, 
		          (void *)&werr,
		          sizeof(UINT32) ) == OK )
	{
	    if (werr != 0)
	    {
	        s = "NMI - write access error";
	    }
	}	
    }
    else if( EXCEP_cacheerr )
    {
	s = "CacheErr";
    }
    else
    {
        if( display )
            DISP( (UINT32)context->cp0_epc );