scs_maint.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef	lint
static        char    *sccsid = "@(#)scs_maint.c	4.1  (ULTRIX)        7/2/90";
#endif	lint

/************************************************************************
 *                                                                      *
 *                      Copyright (c) 1988 - 1989 by                    *
 *              Digital Equipment Corporation, Maynard, MA              *
 *                      All rights reserved.                            *
 *                                                                      *
 *   This software is furnished under a license and may be used and     *
 *   copied  only  in accordance with the terms of such license and     *
 *   with the  inclusion  of  the  above  copyright  notice.   This     *
 *   software  or  any  other copies thereof may not be provided or     *
 *   otherwise made available to any other person.  No title to and     *
 *   ownership of the software is hereby transferred.                   *
 *                                                                      *
 *   The information in this software is subject to change  without     *
 *   notice  and should not be construed as a commitment by Digital     *
 *   Equipment Corporation.                                             *
 *                                                                      *
 *   Digital assumes no responsibility for the use  or  reliability     *
 *   of its software on equipment which is not supplied by Digital.     *
 *                                                                      *
 ************************************************************************
 *
 *
 *   Facility:	Systems Communication Architecture
 *		Systems Communication Services
 *
 *   Abstract:	This module contains Systems Communication Services( SCS )
 *		maintenance service functions.
 *
 *   Creator:	Todd M. Katz	Creation Date:	May 27, 1985
 *
 *   Function/Routines:
 *   
 *   scs_crash_path		Crash Path
 *   scs_reset			Reset Remote Port and System
 *   scs_restart		Restart Remote Port and System
 *   scs_shutdown		Inform Known Systems of Local Shutdown
 *
 *   Modification History:
 *
 *   06-Apr-1989	Pete Keilty
 *	Added include file smp_lock.h
 *
 *   13-Feb-1989	Todd M. Katz		TMK0004
 *	1. Modify TMK0003 to use the shorthand notation Lproc_name when
 *	   refering to the corresponding MSB field.
 *	2. Include header file ../vaxmsi/msisysap.h.
 *
 *   20-Aug-1988	Todd M. Katz		TMK0003
 *	1. SCA event codes have been completed revised.  All former SCS path
 *	   crash codes are now defined as either error events or severe error
 *	   events.  The path crash attribute is only applied by the individual
 *	   port driver routines responsible for crashing paths and only when
 *	   the crashed path is currently open.
 *	2. Modify scs_path_crash() to pass the name of the local SYSAP
 *	   responsible for crashing the path to the appropriate port specific
 *	   routine.  The local SYSAP is required to pass its name within a new
 *	   MSB field( lproc_name ).  This name is passed to the appropriate
 *	   port specific routine in place of the SCS header of a
 *	   datagram/message buffer, the normal occupant of that arguement
 *	   position.
 *
 *   24-Jun-1988	Todd M. Katz		TMK0002
 *	Due to a typo scs_crash_path() was not returning the status
 *	RET_INVPSTATE when directed to crash existing paths in inappropriate
 *	states.  It does now.
 *
 *   02-Jun-1988	Ricky S. Palmer
 *	Removed inclusion of header file ../vaxmsi/msisysap.h
 *
 *   08-Jan-1988	Todd M. Katz		TMK0001
 *	Formated module, revised comments, increased robustness, restructured
 *	code paths, and added SMP support.
 */

/* Libraries and Include Files.
 */
#include		"../h/types.h"
#include		"../h/param.h"
#include		"../h/ksched.h"
#include		"../h/time.h"
#include		"../h/errlog.h"
#include		"../h/smp_lock.h"
#include		"../io/scs/sca.h"
#include		"../io/scs/scaparam.h"
#include		"../io/ci/cippdsysap.h"
#include		"../io/ci/cisysap.h"
#include		"../io/msi/msisysap.h"
#include		"../io/bi/bvpsysap.h"
#include		"../io/gvp/gvpsysap.h"
#include		"../io/uba/uqsysap.h"
#include		"../io/sysap/sysap.h"
#include		"../io/ci/cippdscs.h"
#include		"../io/ci/ciscs.h"
#include		"../io/msi/msiscs.h"
#include		"../io/bi/bvpscs.h"
#include		"../io/gvp/gvpscs.h"
#include		"../io/uba/uqscs.h"
#include		"../io/scs/scs.h"

/* External Variables and Routines.
 */
extern	struct lock_t	lk_scadb;
extern	pccbq		scs_lport_db;

/*   Name:	scs_crash_path	- Crash Path
 *
 *   Abstract:	This function initiates port specific termination of a specific
 *		path to a known system.  The path is disabled, cleaned up, and
 *		all SYSAPs with connections established across the explicitly
 *		failed path are notified of its failure.  Notification occurs
 *		through asynchronous invocation of their connections' control
 *		event routines.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   msb			- Maintenance Services Block pointer
 *	lport_name		-  Local port device name
 *	ov1.lproc_name		-  Local SYSAP name( blank filled )
 *	rport_addr		-  Remote port station address
 *   lk_scadb			- SCA database lock structure
 *   scs_lport_db		- System-wide local port database queue head
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *
 *   Return Values:
 *
 *   RET_SUCCESS		- Initiated path termination
 *   RET_INVPSTATE		- Path in invalid state
 *   RET_NOPATH			- Path not exist
 *
 *   SMP:	The SCA database is locked to postpone potential modifications
 *		to the system-wide local port database while it is being
 *		traversed.  It also allows PB retrieval while preventing
 *		premature PB deletion as required by PD routines which crash
 *		paths.
 */
u_long
scs_crash_path( msb )
    register MSB	*msb;
{
    register PB		*pb;
    register pccbq	*qp;
    register PCCB	*pccb;
    register u_long	status = RET_NOPATH;

    /* The steps involved in crashing a path are as follows:
     *
     * 1. Lock the SCA database.
     * 2. Search the system-wide local port database for the specified port.
     * 3. Retrieve the PB for the specified path.
     * 4. Invoke a PD specific routine to initiate crashing of the path.
     * 5. Unlock the SCA database.
     * 6. Return an appropriate status.
     */
    Lock_scadb()
    for( qp = scs_lport_db.flink; qp != &scs_lport_db; qp = qp->flink ) {
	pccb = Pos_to_pccb( qp, flink );
	if( pccb->lpinfo.name == msb->lport_name ) {
	    if(( pb = ( *pccb->Get_pb )( pccb,
					 ( SCSH * )&msb->rport_addr,
					 NO_BUF ))) {
		if( pb->pinfo.state == PS_OPEN ||
		     pb->pinfo.state == PS_PATH_FAILURE ) {
		    ( void )( *pb->Crash_path )( pccb,
						 pb,
						 E_SYSAP,
						 RETURN_BUF,
						 ( SCSH * )msb->Lproc_name );
		    status = RET_SUCCESS;
		} else {
		    status = RET_INVPSTATE;
		}
	    }
	    break;
	}
    }
    Unlock_scadb()
    return( status );
}

/*   Name:	scs_reset	- Reset Remote Port and System
 *
 *   Abstract:	This function initiates the resetting of a remote port and
 *		system in a port specific fashion.  The remote system does not
 *		have to be known.  Such resettings are best efforts.  Remote
 *		ports and systems are not guaranteed to have been reset.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   msb			- Maintenance Services Block pointer
 *	ov1.force		-  Force resetting of remote port and system
 *	lport_name		-  Local port device name
 *	rport_addr		-  Remote port station address
 *   lk_scadb			- SCA database lock structure
 *   scs_lport_db		- System-wide local port database queue head
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *
 *   Return Values:
 *
 *   RET_SUCCESS		- Initiated remote port and system resetting
 *   RET_ALLOCFAIL		- Failed to allocate a local port buffer
 *   RET_INVLPSTATE		- Local port in invalid state
 *   RET_NOLPORT		- Local port not exist
 *   RET_NOPATH			- Invalid remote port station address
 *
 *   SMP:	The SCA database is locked to postpone potential modifications
 *		to the system-wide local port database while it is being
 *		traversed.
 */
u_long
scs_reset( msb )
    register MSB	*msb;
{
    register pccbq	*qp;
    register PCCB	*pccb;
    register u_long	status = RET_NOLPORT;

    /* The resetting of a remote port and system proceeds as follows:
     *
     * 1. Lock the SCA database.
     * 2. Search the system-wide local port database for the target port.
     * 4. Invoke a PD specific function to initiate resetting of the remote
     *	  port and system.
     * 5. Unlock the SCA database.
     * 6. Return an appropriate status.
     */
    Lock_scadb()
    for( qp = scs_lport_db.flink; qp != &scs_lport_db; qp = qp->flink ) {
	pccb = Pos_to_pccb( qp, flink );
	if( pccb->lpinfo.name == msb->lport_name ) {
	    status = ( *pccb->Remote_reset )( pccb,
					      &msb->rport_addr,
					      msb->Force );
	    break;
	}
    }
    Unlock_scadb()
    return( status );
}

/*   Name:	scs_restart	- Restart Remote Port and System
 *
 *   Abstract:	This function initiates the restarting of a remote port and
 *		system in a port specific fashion.  A reset must have been
 *		previously issued from the the local to the remote port.
 *
 *		The remote system does not have	to be known.  Such restartings
 *		are best efforts.  Remote ports and systems are not guaranteed
 *		to have been restart.
 *
 *		The remote system may optionally be started at a SYSAP supplied
 *		address.  Otherwise, the remote system is started at its
 *		default start address.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   msb			- Maintenance Services Block pointer
 *	lport_name		-  Local port device name
 *	ov1.startaddr		-  Remote system starting address( OPTIONAL )
 *	rport_addr		-  Remote port station address
 *   lk_scadb			- SCA database lock structure
 *   scs_lport_db		- System-wide local port database queue head
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *
 *   Return Values:
 *
 *   RET_SUCCESS		- Initiated remote port and system restarting
 *   RET_ALLOCFAIL		- Failed to allocate a local port buffer
 *   RET_INVLPSTATE		- Local port in invalid state
 *   RET_NOLPORT		- Local port not exist
 *   RET_NOPATH			- Invalid remote port station address
 *
 *   SMP:	The SCA database is locked to postpone potential modifications
 *		to the system-wide local port database while it is being
 *		traversed.
 */
u_long
scs_restart( msb )
    register MSB	*msb;
{
    register pccbq	*qp;
    register PCCB	*pccb;
    register u_long	status = RET_NOLPORT;

    /* The restarting of a remote port and system proceeds as follows:
     *
     * 1. Lock the SCA database.
     * 2. Search the system-wide local port database for the target port.
     * 4. Invoke a PD specific function to initiate restarting of the remote
     *	  port and system.
     * 5. Unlock the SCA database.
     * 6. Return an appropriate status.
     */
    Lock_scadb()
    for( qp = scs_lport_db.flink; qp != &scs_lport_db; qp = qp->flink ) {
	pccb = Pos_to_pccb( qp, flink );
	if( pccb->lpinfo.name == msb->lport_name ) {
	    status = ( *pccb->Remote_start )( pccb,
					      &msb->rport_addr,
					      msb->Startaddr );
	    break;
	}
    }
    Unlock_scadb()
    return( status );
}

/*   Name:	scs_shutdown	- Inform Known Systems of Local Shutdown
 *
 *   Abstract:	This function initiates notification of all known systems of
 *		local system shutdown.  Such notifications are best efforts.
 *		Systems are not guaranteed to have been notified.
 *
 *   Inputs:
 *
 *   IPL_POWER			- Interrupt processor level
 *   scs_lport_db		- System-wide local port database queue head
 *
 *   Outputs:
 *
 *   IPL_POWER			- Interrupt processor level
 *
 *   SMP:	No locks are required.  This routine is only called from
 *		panic() and it is invoked at maximum IPL.  Only the processor
 *		executing this code is operational and this routine can not be
 *		interrupted on this processor.  This guarantees uncompromised
 *		access to the system-wide local port database without locking
 *		the SCA database.
 */
void
scs_shutdown()
{
    register pccbq	*qp;
    register PCCB	*pccb;
    register void	( *down )();

    /* Traverse the system-wide local port database and invoke each local
     * port's PD specific routine to notify those remote systems with paths
     * originating at the port of local system shutdown.
     */
    for( qp = scs_lport_db.flink; qp != &scs_lport_db; qp = qp->flink ) {
	pccb = Pos_to_pccb( qp, flink );
	if(( down = pccb->Shutdown )) {
	    ( void )( *down )( pccb );
	}
    }
}