sh.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

	tp->t_state |= TS_WOPEN;

	if ((tp->t_state&TS_ISOPEN) == 0) {
	    shmodem[unit] = MODEM_DSR_START; /* prevents spurious startups */
	}
	tty_def_open(tp, dev, flag, (shsoftCAR[sh]&(1<<(unit&LINEMASK))));
	shparam(unit);

	/*
	 * Wait for carrier, then process line discipline specific open.
	 */

	/*
	 * Set up receive hold off timer. Manual says we have
	 * to point to line 0 before we set the timer.
	 */
	addr->csr.low = SH_RIE|(0 & LINEMASK);	/* set to line 0 */
	sh_softcsr = SH_RIE|(0 & LINEMASK);
	addr->run.rxtimer = 10;			/* 10 MS hold off time */

	s=spl5();
	if (tp->t_cflag & CLOCAL) {
		/* this is a local connection - ignore carrier */
		tp->t_state |= TS_CARR_ON;
		shmodem[unit] |= MODEM_CTS|MODEM_CD|MODEM_DSR;
		addr->csr.low = SH_RIE|(unit & LINEMASK); /* set to line #*/
		sh_softcsr = SH_RIE|(unit & LINEMASK); /* set to line #*/
							  /* enable interrupts*/
		addr->lnctrl &= ~(SH_MODEM);
		addr->lnctrl |= (SH_DTR|SH_RTS|SH_REN);
		/*
	 	 * Set state bit to tell tty.c not to assign this line as the 
	 	 * controlling terminal for the process which opens this line.
	 	 */
		if ((flag & O_NOCTTY) && (u.u_procp->p_progenv == A_POSIX))
			tp->t_state |= TS_ONOCTTY;
		splx(s);
		return ((*linesw[tp->t_line].l_open)(dev, tp));
	}
/* NOTREACHED (softCAR and CLOCAL always set, i.e., no modem control) */
	addr->csr.low = SH_RIE|(unit & LINEMASK);
	sh_softcsr = SH_RIE|(unit & LINEMASK);
	addr->lnctrl |= (SH_DTR|SH_RTS|SH_MODEM|SH_REN);

	if ((flag & (O_NDELAY|O_NONBLOCK)) == 0) {
		if (shdsr) {
			if ((addr->fun.fs.stat)&SH_DSR) {
				shmodem[unit] |= (MODEM_DSR_START|MODEM_DSR);
				tp->t_dev = dev; /* need it for timeouts */
				timeout(sh_dsr_check, tp, hz*30);
				timeout(sh_dsr_check, tp, hz/2);
			}
		}
		/*
		 * Ignore DSR and immediately look for CD & CTS.
		 */
		else {
			shmodem[unit] |= (MODEM_DSR_START|MODEM_DSR);
			sh_dsr_check(tp);
		}
	}
#ifdef SHDEBUG
	if (shdebug)
		mprintf("shopen:  line=%d, state=%x, pid=%d\n", unit,
			tp->t_state, u.u_procp->p_pid);
#endif
	if (flag & (O_NDELAY|O_NONBLOCK))
		tp->t_state |= TS_ONDELAY;
	else
		while ((tp->t_state&TS_CARR_ON)==0) {
			inuse = tp->t_state&TS_INUSE;
			sleep((caddr_t)&tp->t_rawq, TTIPRI);
 			/*
 			 * See if wakeup is due to a false call.
 			 */
 			if (shmodem[unit]&MODEM_BADCALL){
				splx(s);
 				return(EWOULDBLOCK);
			}
			/* if we opened "block if in use"  and
			 *  the terminal was not inuse at that time
			 *  but is became "in use" while we were
			 *  waiting for carrier then return
			 */
			if ((flag & O_BLKINUSE) && (inuse==0) &&
				(tp->t_state&TS_INUSE)) {
					splx(s);
					return(EALREADY);
			}
		}
	/*
	 * Set state bit to tell tty.c not to assign this line as the 
	 * controlling terminal for the process which opens this line.
	 */
	if ((flag & O_NOCTTY) && (u.u_procp->p_progenv == A_POSIX))
		tp->t_state |= TS_ONOCTTY;
	splx(s);
	return ((*linesw[tp->t_line].l_open)(dev, tp));
}

/*
 * Close a SH line.
 */
/*ARGSUSED*/
shclose(dev, flag)
	dev_t dev;
	int flag;
{
	register struct tty *tp;
	register int unit, s;
	register struct shdevice *addr;
	register sh;
	extern int wakeup();
	int turnoff = 0;

	unit = minor(dev);
	sh = unit >> 3;
	tp = &sh_tty[unit];
	addr = (struct shdevice *)tp->t_addr;
	tp->t_state |= TS_CLOSING;
	if (tp->t_line)
		(*linesw[tp->t_line].l_close)(tp);
	if ((tp->t_cflag&HUPCL) || (tp->t_state&TS_ISOPEN)==0) {
		s = spl5();
		turnoff++;
		addr->csr.low = SH_RIE|(unit & LINEMASK);
		sh_softcsr = SH_RIE|(unit & LINEMASK);
		addr->lnctrl &= ~(SH_DTR|SH_RTS);  /* turn off DTR */
		tp->t_state &= ~TS_CARR_ON; /* prevents recv intr. timeouts */
		if ((tp->t_cflag & CLOCAL) == 0) {
#ifdef SHDEBUG
	if (shdebug)
		mprintf("shclose: DTR drop line=%d, state=%x, pid=%d\n", unit,
			tp->t_state, u.u_procp->p_pid);
#endif

			/* wait an additional 5 seconds for DSR to drop */
			if (shdsr && (addr->fun.fs.stat&SH_DSR)) {
				timeout(wakeup, (caddr_t) &tp->t_dev, 5*hz);
				sleep((caddr_t)&tp->t_dev, PZERO-10);
			}
			timeout(wakeup, (caddr_t) &tp->t_dev, hz/5);
			sleep((caddr_t)&tp->t_dev, PZERO-10);
		}
		splx(s);
	}
#ifdef SHDEBUG
	if (shdebug)
		mprintf("shclose: line=%d, state=%x, pid=%d\n", unit,
			tp->t_state, u.u_procp->p_pid);
#endif
	shsoftCAR[sh] &= ~(1<<(unit&LINEMASK));
	shsoftCAR[sh] |= (1<<(unit&LINEMASK)) & shdefaultCAR[sh];
	ttyclose(tp);  /* remember this will clear out t_state */

	if (turnoff) {
		/* we have to do this after the ttyclose so that output
		 * can still drain
		 */
		s = spl5();
		addr->csr.low = SH_RIE|(unit & LINEMASK);
		addr->lnctrl = NULL; /* turn off interrupts also */
		splx(s);
	}
	shmodem[unit] = 0;
	tty_def_close(tp);
	wakeup((caddr_t)&tp->t_rawq); /* wake up anyone in shopen */
}

shread(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	register struct tty *tp = &sh_tty[minor(dev)];

	return ((*linesw[tp->t_line].l_read)(tp, uio));
}

shwrite(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	register struct tty *tp = &sh_tty[minor(dev)];

	return ((*linesw[tp->t_line].l_write)(tp, uio));
}

/*
 * SH receiver interrupt.
 */
shrint(sh)
	int sh; /* module number */
{
	register struct tty *tp;
	register c, unit;
	register struct shdevice *addr;
	struct tty *tp0;
	register struct uba_device *ui;
	register flg;
	int overrun = 0;
	u_char *modem0, *modem;
	int modem_cont;

	ui = shinfo[sh];
	if (ui == 0 || ui->ui_alive == 0)
		return;
	addr = (struct shdevice *)shmem;
	tp0 = &sh_tty[sh<<3];  /* first tty structure that corresponds
				* to this sh module
				*/
	modem0 = &shmodem[sh<<3];
	/*
	 * Loop fetching characters from receive fifo for this
	 * sh until there are no more in the receive fifo.
	 */
	while ((c = addr->run.rbuf) < 0) {
		/* if c < 0 then data valid is set */
		unit = (c>>8)&LINEMASK;
		tp = tp0 + unit; /* tty struct for this line */
		flg = tp->t_iflag;
		modem = modem0 + unit;
		modem_cont = 0;
#ifdef SHDEBUG
		if (shdebug > 6)
			mprintf("shrint0: c=%x, tp=%x\n", c, tp);
#endif
		/* check for modem transitions */
		if ((c & SH_STAT)==SH_STAT) {
			if (c & SH_DIAG) /* ignore diagnostic info */
				continue;
#ifdef SHDEBUG
			if (shdebug > 6)
				mprintf("shrint: c=%x, tp=%x\n", c, tp);
#endif
			if (tp->t_cflag & CLOCAL)
				continue;

			/* set to line #*/
			addr->csr.low = SH_RIE|(unit & LINEMASK);
			sh_softcsr = SH_RIE|(unit & LINEMASK);

			/* examine modem status */
			
			/*
			 * Drop DTR immediately if DSR has gone away.
			 * If really an active close then do not
			 *    send signals.
			 */

			if ((addr->fun.fs.stat&SH_DSR)==0) {
				if (tp->t_state&TS_CLOSING) {
					untimeout(wakeup, (caddr_t) &tp->t_dev);
					wakeup((caddr_t) &tp->t_dev);
					continue;
				}
				if (tp->t_state&TS_CARR_ON) {
					/*
					 * Only drop line if DSR is followed.
					 */
					if (shdsr)
						sh_tty_drop(tp);
					continue;
				}
			}
			/*
			 * Check for transient CD drops.
			 * Only drop DTR if CD is down for more than 2 secs.
			 */
			if (tp->t_state&TS_CARR_ON)
			    if ((addr->fun.fs.stat&SH_CD)==0){
				if ( *modem & MODEM_CD) {
				    /* only start timer once */
				    if (shdebug)
					mprintf("shrint, cd_drop, tp=%x\n", tp);
				    *modem &= ~MODEM_CD;
				    shtimestamp[minor(tp->t_dev)] = time;
				    timeout(sh_cd_drop, tp, hz*shcdtime);
				    modem_cont = 1;;
				}
			    } else
				/*
				 * CD has come up again.
				 * Stop timeout from occurring if set.
				 * If interval is more than 2 secs then
				 *  drop DTR.
				 */
				if ((*modem&MODEM_CD)==0) {
					untimeout(sh_cd_drop, tp);
					if (sh_cd_down(tp))
						/* drop connection */
						sh_tty_drop(tp);
					*modem |= MODEM_CD;
					modem_cont = 1;;
				}


			/* CTS flow control check */

			if (tp->t_state&TS_CARR_ON)
				if ((addr->fun.fs.stat&SH_CTS)==0) {
					tp->t_state |= TS_TTSTOP;
					*modem &= ~MODEM_CTS;
					if (shdebug)
					   mprintf("shrint: CTS stop, tp=%x\n", tp);
					shstop(tp, 0);
					continue;
				} else if ((*modem&MODEM_CTS)==0) {
					    tp->t_state &= ~TS_TTSTOP;
					    *modem |= MODEM_CTS;
					    if (shdebug)
					       mprintf("shrint: CTS start, tp=%x\n", tp);
					    shstart(tp);
					    continue;
					}

			/*
			 * Avoid calling sh_start_tty for a CD transition if
			 * the connection has already been established.
			 */
			if (modem_cont)
				continue;
			/*
			 * If 500 ms timer has not expired then dont
			 * check anything yet.
			 * Check to see if DSR|CTS|CD are asserted.
			 * If so we have a live connection.
			 * If DSR is set for the first time we allow
			 * 30 seconds for a live connection.
			 */
			if (shdsr) {
				if ((addr->fun.fs.stat&SH_XMIT)==SH_XMIT
				    && (*modem&MODEM_DSR_START)==0)
					sh_start_tty(tp);
				else
				    if ((addr->fun.fs.stat&SH_DSR) &&
					(*modem&MODEM_DSR)==0) {
					*modem |= (MODEM_DSR_START|MODEM_DSR);
					/*
					 * we should not look for CTS|CD for
					 * about 500 ms.
					 */
					timeout(sh_dsr_check, tp, hz*30);
					timeout(sh_dsr_check, tp, hz/2);
				    }
			}
			/*
			 * Ignore DSR but look for CD and CTS.
			 */
			else {
				if ((addr->fun.fs.stat&SH_NODSR)==SH_NODSR)
					sh_start_tty(tp);
			}



			continue;
		}


#ifndef PORTSELECTOR
		if ((tp->t_state&TS_ISOPEN)==0) {
#else
		if ((tp->t_state&(TS_ISOPEN|TS_WOPEN))==0) {
#endif
			wakeup((caddr_t)tp);
			continue;
		}

/*		This code handles the following termio input flags.  Also
 *		listed is what the default should be for propper Ultrix
 *		backward compatibility.
 *
 *		IGNBRK		FALSE
 *		BRKINT		TRUE
 *		IGNPAR		TRUE
 *		PARMRK		FALSE
 *		INPCK		TRUE
 *		ISTRIP		TRUE 		
 */

					/* tp->t_flags should be register */
		/* SH_FERR is interpreted as a break */
		if (c & SH_FERR) {
			/*
			 * If configured for trusted path, initiate
			 * trusted path handling.
			 */
			if (do_tpath) {
				tp->t_tpath |= TP_DOSAK;
				(*linesw[tp->t_line].l_rint)(c, tp);
				break;
			}
			if (flg & IGNBRK)
				continue;
			if (flg & BRKINT) {
#ifdef SHDEBUG
				if (shdebug)
					mprintf("shrint: BREAK RECEIVED\n");
#endif SHDEBUG
				if ((tp->t_lflag_ext & PRAW) && 
					(tp->t_line != TERMIODISC))
					c = 0;
				else {
				    ttyflush(tp, FREAD|FWRITE);
#ifdef SHDEBUG
				    if (shdebug)
					mprintf("sending signal to tp->t_pgrp = %d\n", tp->t_pgrp);
#endif SHDEBUG
				    gsignal(tp->t_pgrp, SIGINT);
				    continue;
				}
			}
			/*
			 * TERMIO: If neither IGNBRK or BRKINT is set, a
			 * break condition is read as a single '\0',
			 * or if PARMRK is set as '\377','\0,'\0'.
			 */
			else {
				if (flg & PARMRK){
					(*linesw[tp->t_line].l_rint)(0377,tp);
					(*linesw[tp->t_line].l_rint)(0,tp);
				}
				c = 0;
			}
		
		}
		/* Parity Error */
		else if (c & SH_PERR){
			/*