mscp_tape.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
    { TAPE_DATAGRAM,	tmscp_invevent },		/*		      */
};

/* Write tape mark command states.
 */
STATE tmscp_wtm_states[] = {

    /* Wriet tape mark initial state.
     */
    { ST_WTM_INITIAL,	tmscp_invevent },		/* EV_NULL	      */
    { ST_WTM_INITIAL,	mscp_alloc_rspid },		/* EV_INITIAL	      */
    { ST_WTM_INITIAL,	mscp_alloc_msg },		/* EV_RSPID	      */
    { ST_WTM_INITIAL,	tmscp_writetmcm },		/* EV_MSGBUF	      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/* EV_MAPPING	      */
    { ST_WTM_INITIAL,	tmscp_writetmem },		/* EV_ENDMSG	      */
    { ST_WTM_INITIAL,	tmscp_invevent},			/* EV_TIMEOUT	      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
    { ST_WTM_INITIAL,	tmscp_invevent },		/*		      */
};


/* Reposition tape command states.
 * Repositions files (tape marks), tape objects, nowhere.
 */
STATE tmscp_rpo_states[] = {

    /* Reposition tape initial state.
     */
    { ST_RPO_INITIAL,	tmscp_invevent },		/* EV_NULL	      */
    { ST_RPO_INITIAL,	mscp_alloc_rspid },		/* EV_INITIAL	      */
    { ST_RPO_INITIAL,	mscp_alloc_msg },		/* EV_RSPID	      */
    { ST_RPO_INITIAL,	tmscp_reposcm },		/* EV_MSGBUF	      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/* EV_MAPPING	      */
    { ST_RPO_INITIAL,	tmscp_reposem },		/* EV_ENDMSG	      */
    { ST_RPO_INITIAL,	tmscp_invevent},			/* EV_TIMEOUT	      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
};


/* Reposition tape records command states.
 * Reposition tape records only.
 */
STATE tmscp_rec_states[] = {

    /* Reposition tape initial state.
     */
    { ST_RPO_INITIAL,	tmscp_invevent },		/* EV_NULL	      */
    { ST_RPO_INITIAL,	mscp_alloc_rspid },		/* EV_INITIAL	      */
    { ST_RPO_INITIAL,	mscp_alloc_msg },		/* EV_RSPID	      */
    { ST_RPO_INITIAL,	tmscp_repreccm },		/* EV_MSGBUF	      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/* EV_MAPPING	      */
    { ST_RPO_INITIAL,	tmscp_reposem },		/* EV_ENDMSG	      */
    { ST_RPO_INITIAL,	tmscp_invevent},			/* EV_TIMEOUT	      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
    { ST_RPO_INITIAL,	tmscp_invevent },		/*		      */
};

/* Get unit status command states.
 */
STATE tmscp_gtu_states[] = {

    /* Reposition tape initial state.
     */
    { ST_GTU_INITIAL,	tmscp_invevent },		/* EV_NULL	      */
    { ST_GTU_INITIAL,	mscp_alloc_rspid },		/* EV_INITIAL	      */
    { ST_GTU_INITIAL,	mscp_alloc_msg },		/* EV_RSPID	      */
    { ST_GTU_INITIAL,	tmscp_gtuntcm },		/* EV_MSGBUF	      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/* EV_MAPPING	      */
    { ST_GTU_INITIAL,	tmscp_gtuntem },		/* EV_ENDMSG	      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/* EV_TIMEOUT	      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_GTU_INITIAL,	tmscp_invevent },		/*		      */
};


/* Set unit characteristics command states.
 */
STATE tmscp_stu_states[] = {

    /* Set characteristics initial state.
     */
    { ST_STU_INITIAL,	tmscp_invevent },		/* EV_NULL	      */
    { ST_STU_INITIAL,	mscp_alloc_rspid },		/* EV_INITIAL	      */
    { ST_STU_INITIAL,	mscp_alloc_msg },		/* EV_RSPID	      */
    { ST_STU_INITIAL,	tmscp_setunitcm },		/* EV_MSGBUF	      */
    { ST_STU_INITIAL,	tmscp_invevent },		/* EV_MAPPING	      */
    { ST_STU_INITIAL,	tmscp_setunitem },		/* EV_ENDMSG	      */
    { ST_STU_INITIAL,	tmscp_invevent },		/* EV_TIMEOUT	      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_STU_INITIAL,	tmscp_invevent },		/*		      */
};


/* Erase tape states.
 */
STATE tmscp_era_states[] = {

    /* Erase tape initial state.
     */
    { ST_ERA_INITIAL,	tmscp_invevent },		/* EV_NULL	      */
    { ST_ERA_INITIAL,	mscp_alloc_rspid },		/* EV_INITIAL	      */
    { ST_ERA_INITIAL,	mscp_alloc_msg },		/* EV_RSPID	      */
    { ST_ERA_INITIAL,	tmscp_erasecm },		/* EV_MSGBUF	      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/* EV_MAPPING	      */
    { ST_ERA_INITIAL,	tmscp_eraseem },		/* EV_ENDMSG	      */
    { ST_ERA_INITIAL,	tmscp_invevent},			/* EV_TIMEOUT	      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
    { ST_ERA_INITIAL,	tmscp_invevent },		/*		      */
};

/* Data transfer states.
 */
STATE tmscp_xfr_states[] = {

    /* Unit online initial state.
     */
    { ST_XF_INITIAL,	tmscp_invevent },		/* EV_NULL	      */
    { ST_XF_INITIAL,	mscp_alloc_rspid },		/* EV_INITIAL	      */
    { ST_XF_INITIAL,	mscp_alloc_msg },		/* EV_RSPID	      */
    { ST_XF_INITIAL,	mscp_map_buffer },		/* EV_MSGBUF	      */
    { ST_XF_INITIAL,	tmscp_transfercm },		/* EV_MAPPING	      */
    { ST_XF_INITIAL,	tmscp_transferem },		/* EV_ENDMSG	      */
    { ST_XF_INITIAL,	tmscp_invevent },		/* EV_TIMEOUT	      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
    { ST_XF_INITIAL,	tmscp_invevent },		/*		      */
};

/* Flush controller's write-back cache command state.
 */
STATE tmscp_flu_states[] = {

    /* flush command initial state.
     */
    { ST_FLU_INITIAL,	tmscp_invevent },		/* EV_NULL	      */
    { ST_FLU_INITIAL,	mscp_alloc_rspid },		/* EV_INITIAL	      */
    { ST_FLU_INITIAL,	mscp_alloc_msg },		/* EV_RSPID	      */
    { ST_FLU_INITIAL,	tmscp_flushcm },		/* EV_MSGBUF	      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/* EV_MAPPING	      */
    { ST_FLU_INITIAL,	tmscp_flushem },		/* EV_ENDMSG	      */
    { ST_FLU_INITIAL,	tmscp_invevent},		/* EV_TIMEOUT	      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
    { ST_FLU_INITIAL,	tmscp_invevent },		/*		      */
};
/*
 *
 *   Name:	tmscpopen	- Open Tape Unit
 *
 *   Abstract:	
 *
 *   Inputs:
 *
 *   Outputs:
 *
 *
 *   Return	NONE
 *   Values:
 */

int 
tmscpopen(dev, flag)
    dev_t	dev;
    int		flag;

{

	UNITB	*up;
	REQB	*rp;
	int	retries;

	Dprint6("tmscpopen\n");

	/* If there is no known unit corresponding to the device
	 * number, return an error.
	 */
	if(( up = Dev_to_Tunitb( dev )) == NULL ) {
		Dprint8("open: return ENXIO unknown unit\n");
		return( ENXIO );
	}

	up->tms_category_flags &= ~DEV_RWDING;

	/* If the unit is in use fail as the drive is in use already.
	 */
	if(up->Tflags.tms_inuse){
		Dprint8("open: return ENXIO unit in use\n");
		return(ENXIO);
	}
	/*
	 * Mark the unit in use so opens will fail for the next user
	 * that wants the tape drive.  
	 */
	up->Tflags.tms_inuse = 1;

	/* Set drive type.
	 */
	up->sel = SEL( dev );

	/* Do a get unit status insure that the states have not changed.
	 * Clear online so that it's status will be set by the get unit status.
	 */
	up->flags.online = 0;
	up->Tflags.tms_wait = 1;
	rp = (REQB *) mscp_alloc_reqb( up, NULL, tmscp_gtu_states,(u_long) 0, (u_long) 0 );

	retries = RETRY_COUNT;
	while( up->Tflags.tms_wait  && ( --retries >= 0 ) ) {
		timeout( wakeup, ( caddr_t )rp, hz );
		( void )sleep(( caddr_t )rp, PSWP+1 );
		untimeout(wakeup,(caddr_t)rp);   /* to be sure*/
	}
	Time_Check(up->Tflags.tms_wait, retries, "gtu in open");
	up->Tflags.tms_wait = 0;
	/* If the unit is already online.  This would be the case for a 
	 * no-rewind device which is already out on the tape.
	 * Issue a reposition to clear outstanding serious exceptions which 
	 * would be set by encountering a tape mark when a previous open to
	 * the no-rewind device has read to the tape mark.  This allows for
	 * a transition into the next file.  If the device isn't online the
	 * serious exception would be explicitly cleared by the online states.
	 * return success.
	 *
	 * The tmscp_rpo_states clears flags and sets up up->tms_position
	 * to a known value.
	 */
	if( up->flags.online ) {
		Dprint8("OPEN unit already on line\n");
		up->Tflags.tms_wait = 1;
		rp = (REQB *) mscp_alloc_reqb( up, NULL, tmscp_rpo_states, (u_long) MSCP_MD_OBJCT, (u_long) 0 );
		retries = RETRY_COUNT;
		while( up->Tflags.tms_wait  && ( --retries >= 0 ) ) {
			timeout( wakeup, ( caddr_t )rp, hz );
			( void )sleep(( caddr_t )rp, PSWP+1 );
			untimeout(wakeup, ( caddr_t )rp, hz );
		}
		Time_Check(up->Tflags.tms_wait, retries, "rpo in open");
		up->Tflags.tms_wait = 0;

		/* There have been cases on the TU81 where an availcm failed
		 * to bring the unit into an available state.  As a result the
		 * state is online which would prevent setting of the tape
		 * density which was otherwise done by the onlineinit.
		 * To work around this problem, check to see if we are at BOT.
		 * If so then set the tape density to the value determined by
		 * the previous get unit status.
		 */
		if (up->tms_position == 0) {
			Dprint8("OPEN, online at BOT, set attributes\n");
			up->Tflags.tms_wait = 1;
			rp = (REQB *) mscp_alloc_reqb( up, NULL, tmscp_stu_states, (u_long) 0, (u_long) 0 );
			retries = RETRY_COUNT;
			while( up->Tflags.tms_wait  && ( --retries >= 0 ) ) {
				timeout( wakeup, ( caddr_t )rp, hz );
				( void )sleep(( caddr_t )rp, PSWP+1 );
				untimeout(wakeup, ( caddr_t )rp, hz );
			}
			Time_Check(up->Tflags.tms_wait, retries, "stu in open");
			up->Tflags.tms_wait = 0;
		}
		/*
		 * This is a check to see if the hardware went out from under
		 * us.  What could happen is that the initial get unit status
		 * stated that the unit is online (not available).  Since that
		 * time the controller has changed its mind and became 
		 * available.  If this happens then don't return.  This will
		 * cause an online sequence to be performed to try to recover.
		 * This failure has been observed on the TU81+ and the TBK70.
		 */
	        if ( up->tms_status != MSCP_ST_AVLBL) { 
			return( 0 );
		}
		Dprint8("tmscpopen: unit went available.\n");
	}

	/* Zero saved cmd_ref used by ABORT process.
	 */
	up->cmd_ref = 0;

	/* Insure the tape flags are zero
	 * clear_Sflags is used as quick way to zero out all the bitfields.
	 * this introduces a small window (for SMP) where another open could 
	 * come in between these two instructions.
	 */
	up->clear_Sflags = 0;
	up->Tflags.tms_inuse = 1;
	up->tms_flags = 0;

	/* Start an online sequence
	 */
	rp = (REQB *) mscp_alloc_reqb( up,( struct buf * ) NULL, tmscp_onl_states, (u_long) 0, (u_long) 0 );

	retries = RETRY_COUNT;
	while( !up->flags.online && up->flags.online_ip && --retries >= 0 ) {
		timeout( wakeup, ( caddr_t )rp, hz );
		( void )sleep(( caddr_t )rp, PSWP+1 );
		untimeout(wakeup,(caddr_t)rp);   /* to be sure*/
	}
	/*
	 * If the end message wasn't received before the time expired then
	 * log this as a driver problem.
	 */
	if (!up->flags.online && up->flags.online_ip && (retries < 0)) {