scs_subr.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef	lint
static char *sccsid = "@(#)scs_subr.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 )
 *		miscellaneous routines and functions.  Some of these functions
 *		are invokable only by port drivers while others are for use
 *		only by SCS.  Still others may be invoked by anyone( SYSAPs,
 *		SCS, PDs ).
 *
 *   Creator:	Todd M. Katz	Creation Date:	July 7, 1985
 *
 *   Function/Routines:
 *
 *   scs_alloc_buf		Allocate all Message and Datagram Buffers
 *   scs_choose_path		Choose Path for New Connection
 *   scs_dealloc_buf		Deallocate all Message and Datagram Buffers
 *   scs_dispose_msg		Dispose of Application Message Buffer
 *   scs_init_cmsb		Initialize CMSB for Notifying SYSAP of Event
 *   scs_initialize		Initialize SCS
 *   scs_unix_to_vms		Convert UNIX Time to VMS Time
 *
 *   Modification History:
 *
 *   14-Sep-1989	Pete Keilty
 *	1. Add bcopy for strings instead of cast u_long assign.
 *	   Mips cpu's needed this for alignment.
 *	2. Removed ifdef mips and ifdef vax which where no longer needed.
 *
 *   30-May-89		Darrell A. Dunnuck
 *	Added include of ../../machine/common/cpuconf.h -- cpu types
 *	were moved there.  Removed the include of ../machine/cpu.h.
 *
 *   06-Apr-1989	Pete Keilty
 *	Added include file smp_lock.h
 *
 *   03-Mar-1989	Todd M. Katz		TMK0003
 *	1. Modify scs_init_cmsb() to always return the connection
 *	   identification number regardless of event status.
 *	2. Include header file ../vaxmsi/msisysap.h.
 *	3. Use the ../machine link to refer to machine specific header files.
 *
 *   05-Jul-1988	Todd M. Katz		TMK0002
 *	1. Include limits.h from ../h instead of from /usr/include.
 *	2. Macros Copy_name() and Copy_data() have been renamed to Move_name()
 *	   and Move_data() respectively.
 *
 *   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/time.h"
#include		"../h/param.h"
#include		"../h/ksched.h"
#include		"../h/dyntypes.h"
#include		"../h/limits.h"
#include		"../h/utsname.h"
#ifdef vax
#include		"../machine/mtpr.h"
#endif vax
#include		 "../../machine/common/cpuconf.h"
#include		"../h/kmalloc.h"
#include		"../h/errlog.h"
#include		"../h/smp_lock.h"
#include		"../io/scs/sca.h"
#include		"../io/scs/scaparam.h"
#include		"../io/scs/scamachmac.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 timezone	tz;
extern	int		cpu;
extern	SCSIB		lscs;
extern	struct utsname	utsname;
extern	struct timeval  boottime;
extern	struct lock_t	lk_scadb;
extern	CBVTDB		*scs_cbvtdb;
extern	scaaddr		scs_system_id;
extern	void		( *scs_disable )(), scs_shutdown(), scs_unix_to_vms();
extern	u_char		*cpu_types[], scs_node_name[];
extern	u_long		scs_cushion, scs_dg_size, scs_max_conns, scs_msg_size;

/*   Name:	scs_alloc_buf	- Allocate all Message and Datagram Buffers
 *
 *   Abstract:	This function allocates all requested message and datagram
 *		buffers and adds them to the appropriate port's free message
 *		and datagram pools.
 *
 *		Partial allocation of either datagram or message buffers may
 *		occur.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cb				- Connection Block pointer
 *   ndgs			- Number of datagrams to allocate and add
 *   nmsgs			- Number of messages to allocate and add
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cb				- Connection Block pointer
 *	cinfo.dg_credit		-  Number of datagram credits
 *	cinfo.pend_rec_credit	-  Number of credits pending extension
 *
 *   Return Values:
 *
 *   RET_SUCCESS		- Successful buffer allocation
 *   RET_ALLOCFAIL		- Unsuccessful buffer allocation
 *
 *   SMP:	The CB is locked( EXTERNALLY ) to synchronize access and
 *		prevent premature deletion whenever it formerly resided within
 *		the system-wide configuration database.  It is locked through
 *		its CBVTE.
 *
 *		The PB itself must NOT be EXTERNALLY locked as required by the
 *		PD routines which add datagram and message buffers to the
 *		appropriate local port datagram and message free pools.
 */
u_long
scs_alloc_buf( cb, nmsgs, ndgs )
    register CB		*cb;
    u_long		nmsgs;
    u_long		ndgs;
{
    register SCSH	*scsbp;

    /* Allocate the specified number of message and datagram buffers and add
     * them to the appropriate port's free message and datagram pools
     * respectively.  Return immediately on allocation errors without removing
     * allocated buffers from the appropriate pools and deallocating them.
     */
    for( ; nmsgs; --nmsgs, ++cb->cinfo.pend_rec_credit ) {
	if(( scsbp = ( *cb->Alloc_msg )( cb->pccb ))) {
	    ( void )( *cb->Add_msg )( cb->pccb, scsbp );
	} else {
	    return( RET_ALLOCFAIL );
	}
    }
    for( ; ndgs; --ndgs, ++cb->cinfo.dg_credit ) {
	if(( scsbp = ( *cb->Alloc_dg )( cb->pccb ))) {
	    ( void )( *cb->Add_dg )( cb->pccb, scsbp );
	} else {
	    return( RET_ALLOCFAIL );
	}
    }
    return( RET_SUCCESS );
}

/*   Name:	scs_choose_path	- Choose Path for New Connection
 *
 *   Abstract:	This function chooses the path over which an attempt is made to
 *		establish a new logical SCS connection.  The current algorithm
 *		is to choose an open path to the target system with the least
 *		number of logical SCS connections.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   sb				- System Block pointer
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *
 *   Return Values:
 *
 *   Address of Path Block representing the chosen path
 *   Otherwise NULL if path could not be chosen
 *
 *   SMP:	The SCA database is locked( EXTERNALLY ) allowing for traversal
 *		of the system-wide configuration database.
 */
PB *
scs_choose_path( sb )
    register SB		*sb;
{
    register pbq	*pb;
    register PB		*save = NULL;

    for( pb = sb->pbs.flink; pb != &sb->pbs; pb = pb->flink ) {
	if( Pb->pinfo.state == PS_OPEN ) {
	    if( save == NULL || save->pinfo.nconns > Pb->pinfo.nconns ) {
		save = Pb;
	    }
	}
    }
    return( save );
}

/*   Name:	scs_dealloc_buf	- Deallocate all Message and Datagram Buffers
 *
 *   Abstract:	This function deallocates all of a CB's datagram and message
 *		buffers which it removes from the appropriate port's free
 *		datagram and message pools.  It also removes and deallocates
 *		one message buffer for each block data transfer currently in
 *		progress.
 *
 *		Partial removal of either datagram or message buffers may
 *		occur.
 *
 *		NOTE: The appropriate port drivers are always responsible for
 *		      the clean up of all port specific resources associated
 *		      with failed local ports including free datagram and
 *		      message buffers.  SCS must never attempt to dispose of
 *		      such resources during clean up of the paths and
 *		      connections associated with such failed ports.
 *		
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cb				- Connection Block pointer
 *
 *   Outputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cb				- Connection Block pointer
 *	cinfo.dg_credit		-  0
 *	cinfo.ntransfers	-  0
 *	cinfo.pend_rec_credit	-  0
 *	cinfo.rec_credit	-  0
 *
 *   Return Values:
 *
 *   RET_SUCCESS		- Successful deallocation of all buffers
 *   RET_FAILURE		- Error encountered deallocating buffers
 *
 *   SMP:	The CB is locked( EXTERNALLY ) to synchronize access and
 *		prevent premature deletion.  It is locked through its CBVTE.
 *
 *		The PB itself must NOT be EXTERNALLY locked as required by the
 *		PD routines which remove datagram and message buffers from the
 *		appropriate local port datagram and message free pools.
 */
u_long
scs_dealloc_buf( cb )
    register CB		*cb;
{
    register u_long	nbs;
    register SCSH	*scsbp,
			*( *remove )() = cb->Remove_msg;
    register void	( *dealloc )() = cb->Dealloc_msg;
    register u_long	status = RET_SUCCESS;

    for( nbs = ( cb->cinfo.rec_credit	   +
		 cb->cinfo.pend_rec_credit +
		 cb->cinfo.ntransfers ),
	 cb->cinfo.rec_credit = 0,
	 cb->cinfo.pend_rec_credit = 0,
	 cb->cinfo.ntransfers = 0;
	 nbs;
	 --nbs ) {
	if(( scsbp = ( *remove )( cb->pccb ))) {
	    ( void )( *dealloc )( cb->pccb, scsbp );
	} else {
	    status = RET_FAILURE;
	    break;
	}
    }
    for( remove = cb->Remove_dg,
	 dealloc = cb->Dealloc_dg,
	 nbs = cb->cinfo.dg_credit,
	 cb->cinfo.dg_credit = 0;
	 nbs;
	 --nbs ) {
	if(( scsbp = ( *remove )( cb->pccb ))) {
	    ( void )( *dealloc )( cb->pccb, scsbp );
	} else {
	    status = RET_FAILURE;
	    break;
	}
    }
    return( status );
}

/*   Name:	scs_dispose_msg	- Dispose of Application Message Buffer
 *
 *   Abstract:	This function disposes of an application message buffer on a
 *		specific logical SCS connection according to the connection's
 *		current credit situation.  The buffer is either deallocated or
 *		converted into a receive message buffer for the connection.
 *
 *		Conversion of the application message buffer into a receive
 *		message buffer may trigger explicit extension of send credits
 *		across the logical SCS connection.
 *
 *   Inputs:
 *
 *   IPL_SCS			- Interrupt processor level
 *   cb				- Connection Block pointer
 *	cinfo.cstate		-  CS_OPEN