wt.c

早期freebsd实现

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)wt.c	8.1 (Berkeley) 6/11/93
 */

/*
 *
 * Copyright (c) 1989 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Authors: Robert Baron
 * 
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  [e-mail]
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#include "wt.h"
#if NWT > 0
/* 
 * HISTORY
 * $Log:	wt.c,v $
 * Revision 2.2.1.3  90/01/08  13:29:38  rvb
 * 	Add Intel copyright.
 * 	[90/01/08            rvb]
 * 
 * Revision 2.2.1.2  89/12/21  18:00:09  rvb
 * 	Change WTPRI to make the streamer tape read/write
 * 	interruptible. 		[lin]
 * 
 * Revision 2.2.1.1  89/11/10  09:49:49  rvb
 * 	ORC likes their streamer port at 0x288.
 * 	[89/11/08            rvb]
 * 
 * Revision 2.2  89/09/25  12:33:02  rvb
 * 	Driver was provided by Intel 9/18/89.
 * 	[89/09/23            rvb]
 * 
 */

/*
 *
 *  Copyright 1988, 1989 by Intel Corporation
 *
 *	Support Bell Tech QIC-02 and WANGTEK QIC-36 or QIC-02
 */

#include <sys/param.h>
#include <sys/buf.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/user.h>

#include <i386/isa/wtreg.h>

#ifdef	ORC
unsigned wtport = 0x288;	/* base I/O port of controller	*/
#else	ORC
unsigned wtport = 0x300;	/* base I/O port of controller	*/
#endif	ORC
				/* standard = 0x300		*/
				/* alternate = 0x338		*/

unsigned wtchan = 1;		/* DMA channel number		*/
				/* stardard = 1			*/
				/* hardware permits 1, 2 or 3.	*/
		                /* (Avoid DMA 2: used by disks) */

int	first_wtopen_ever = 1;


#define	ERROR 		1	/* return from tape routines */
#define	SUCCESS		0	/* return from tape routines */

int	wci = 0;
int	exflag = 0;
int	bytes = 0;

static	unsigned char eqdma = 0x8;
static	unsigned char pagereg = 0x83;
static	unsigned char dmareg = 2;
static	unsigned char dma_write = 0x49;
static	unsigned char dma_read = 0x45;
static	unsigned char dma_done = 2;
static	unsigned char mode = 0;
static	unsigned char mbits;	/* map bits into each other */
static	long bufptr;
static	unsigned numbytes;
/*
_wci		dw	0	; interrupt chain finished normally
_exflag		dw	0	; exception variable
_bytes		dw	0	; current bytes

eqdma		db	8h	; enable dma command: ch1,ch2=8h, ch3=10h
pagereg		db	83h	; ch1=83h, ch2=81h, ch3=82h
dmareg		db	2	; ch1=2, ch2=4, ch3=6
dma_write	db	49h	; write dma command: 48h+_wtchan
dma_read	db	45h	; read dma command: 44h+_wtchan
dma_done	db	2	; dma done flag: 1<<_wtchan
mode		db	0	; dma operation mode
lbufptr		dw	0	; buffer pointer to data buffers, low word
hbufptr		dw	0	; buffer pointer to data buffers, high word
numbytes	dw	0	; number of bytes to read or write (new)
*/

#define PAGESIZ		4096
#define HZ		60

/* tape controller ports */
#define STATPORT	wtport
#define CTLPORT		STATPORT
#define CMDPORT		(wtport+1)
#define DATAPORT	CMDPORT

/* defines for reading out status from wangtek tape controller */
#define READY   	0x01    /* ready bit define        */
#define EXCEP		0x02	/* exception bit define    */
#define STAT		(READY|EXCEP)
#define	RESETMASK	0x7
#define	RESETVAL	(RESETMASK & ~EXCEP)

/* tape controller control bits (CTLPORT) */
#define	ONLINE	0x01
#define	RESET	0x02
#define	REQUEST	0x04		/* request command */
#define	CMDOFF	0xC0

/* QIC-02 commands (CMDPORT) */
#define	RDDATA	0x80		/* read data */
#define	READFM	0xA0		/* read file mark */
#define	WRTDATA	0x40		/* write data */
#define	WRITEFM	0x60		/* write file mark */
#define	RDSTAT	0xC0		/* read status command */
#define	REWIND	0x21		/* rewind command (position+bot) */

/* 8237 DMA controller regs */
#define	STATUSREG	0x8
#define MASKREG		0xA
#define MODEREG		0xB
#define CLEARFF		0xC

/* streamer tape block size */
#define BLKSIZE	512

/* Tape characteristics */
#define	NBPS		512	/* 512-byte blocks */
#define	ERROR 		1	/* return from tape routines */
#define	SUCCESS		0	/* return from tape routines */

/* Minor devs */
#define	TP_REWCLOSE(d)	((minor(d)&04) == 0) /* Rewind tape on close if read/write */
#define	TP_DENS(dev)	((minor(dev) >> 3) & 03) /* set density */
#define TPHOG(d)	0	/* use Hogproc during tape I/O	*/

/* defines for wtflags */
#define	TPINUSE	0x0001		/* tape is already open */
#define	TPREAD	0x0002		/* tape is only open for reading */
#define	TPWRITE	0x0004		/* tape is only open for writing */
#define	TPSTART 0x0008		/* tape must be rewound and reset */
#define	TPDEAD	0x0010		/* tape drive does not work or driver error */
#define	TPSESS	0x0020		/* no more reads or writes allowed in session */
				/* for example, when tape has to be changed */
#define	TPSTOP	0x0040		/* Stop command outstanding */
#define	TPREW	0x0080		/* Rewind command outstanding, see wtdsl2() */
#define	TPVOL	0x0100		/* Read file mark, or hit end of tape */
#define	TPWO	0x0200		/* write command outstanding */
#define	TPRO	0x0400		/* read command outstanding */
#define TPWANY	0x0800		/* write command requested */
#define TPRANY	0x1000		/* read command requested */
#define	TPWP	0x2000		/* write protect error seen */

unsigned int	wtflags = TPSTART;	/* state of tape drive */

struct	buf	rwtbuf;		/* header for raw i/o */
struct  proc	*myproc;	/* process which opened tape driver */

char wtimeron;			/* wtimer() active flag */
char wtio;			/* dma (i/o) active flag */
char isrlock;			/* isr() flag */

struct proc * Hogproc;	/* no Hogproc on Microport */
#define	ftoseg(x)	((unsigned) (x >> 16))

struct	wtstatus {
	ushort	wt_err;		/* code for error encountered */
	ushort	wt_ercnt;	/* number of error blocks */
	ushort	wt_urcnt;	/* number of underruns */
}	wterror;

/* defines for wtstatus.wt_err */
#define	TP_POR		0x100	/* Power on/reset occurred */
#define	TP_RES1		0x200	/* Reserved for end of media */
#define	TP_RES2		0x400	/* Reserved for bus parity */
#define	TP_BOM		0x800	/* Beginning of media */
#define	TP_MBD		0x1000	/* Marginal block detected */
#define	TP_NDT		0x2000	/* No data detected */
#define	TP_ILL		0x4000	/* Illegal command */
#define	TP_ST1		0x8000	/* Status byte 1 bits */
#define	TP_FIL		0x01	/* File mark detected */
#define	TP_BNL		0x02	/* Bad block not located */
#define	TP_UDA		0x04	/* Unrecoverable data error */
#define	TP_EOM		0x08	/* End of media */
#define	TP_WRP		0x10	/* Write protected cartridge */
#define	TP_USL		0x20	/* Unselected drive */
#define	TP_CNI		0x40	/* Cartridge not in place */
#define	TP_ST0		0x80	/* Status byte 0 bits */

/* Grounds for reporting I/O error to user */
#define	TP_ERR0		(TP_BNL|TP_UDA|TP_WRP|TP_CNI|TP_FIL|TP_EOM|TP_USL)
#define	TP_ERR1		(TP_MBD|TP_NDT|TP_ILL)
/* TP_ILL should never happen! */
/*
#define	TP_ERR0		0x7f
#define	TP_ERR1		0x7700
*/

/* defines for reading out status from wangtek tape controller */
#define READY   	0x01    /* ready bit define        */
#define EXCEP		0x02	/* exception bit define    */

/* sleep priority */
#define WTPRI	(PZERO+10)

char	pagebuf[NBPS];		/* buffer of size NBPS */
unsigned long	pageaddr;	/* physical addr of pagebuf */
				/* pageaddr is used with DMA controller */
time_t Hogtime;			/* lbolt when Hog timer started */
extern time_t	lbolt;

#define	debug	printf

/*
 * Strategy routine.
 *
 * Arguments:
 *  Pointer to buffer structure
 * Function:
 *  Start transfer.
 *
 * It would be nice to have this multiple-threaded.
 * There is a version of dump from Berkeley that works with multiple processes
 * trading off with disk & tape I/O.
 */

int
wtstrategy(bp)
register struct buf *bp;
{
	unsigned ucnt1, ucnt2, finished;
	unsigned long adr1, adr2;
	int	bad;

	adr1 = kvtop(bp->b_un.b_addr);
#ifdef DEBUG
	debug("bpaddr %x\n", adr1);
#endif
	ucnt1 = bp->b_bcount;
	ucnt2 = 0;
	adr2 = 0;
#ifdef DEBUG
	debug("WTstart: adr1 %lx cnt %x\n", adr1, ucnt1);
#endif
	if (ftoseg(adr1) != ftoseg(adr1 + (unsigned) ucnt1 - 1))
	{
		adr2 = (adr1 & 0xffff0000L) + 0x10000L;
		ucnt2 = (adr1 + ucnt1) - adr2;
		ucnt1 -= ucnt2;
	}
	/* at file marks and end of tape, we just return '0 bytes available' */
	if (wtflags & TPVOL) {
		bp->b_resid = bp->b_bcount;
		goto xit;
	}
	if ((Hogproc == (struct proc *) 0) && TPHOG(bp->b_dev))
	{
#ifdef DEBUG
		printf("setting Hogproc\n");
#endif
		Hogtime = 0;
		Hogproc = myproc;
	}
	if (bp->b_flags & B_READ) {
		bad = 0;

		/* For now, we assume that all data will be copied out */
		/* If read command outstanding, just skip down */
		if (!(wtflags & TPRO)) {
			if (ERROR == wtsense(TP_WRP))	/* clear status */
				goto errxit;
#ifdef DEBUG
			debug("WTread: Start read\n");
#endif
			if (!(wtflags & TPREAD) || (wtflags & TPWANY) ||
			    (rstart() == ERROR))  {
#ifdef DEBUG
				debug("Tpstart: read init error\n"); /* */
#endif
				goto errxit;
			}
			wtflags |= TPRO|TPRANY;
		}

		finished = 0;
		/* Take a deep breath */
		if (ucnt1) {
			if ((rtape(adr1, ucnt1) == ERROR) &&
					(wtsense(TP_WRP) == ERROR))
				goto endio;
			/* wait for it */
			bad = pollrdy();
			finished = bytes;
			if (bad)
				goto endio;
		}
		/* if a second I/O region, start it */
		if (ucnt2) {
			if ((rtape(adr2, ucnt2) == ERROR) &&
					(wtsense(TP_WRP) == ERROR))
				ucnt2 = 0;	/* don't poll for me */
			}

		/* if second i/o pending wait for it */
		if (ucnt2) {
			pollrdy();
			/* whether pollrdy is ok or not */
			finished += bytes;
		}
	} else {
		if (wtflags & TPWP)	/* write protected */
			goto errxit;

		/* If write command outstanding, just skip down */
		if (!(wtflags & TPWO)) {
			if (ERROR == wtsense(0))	/* clear status */
			{
#ifdef DEBUG
				debug("TPstart: sense 0\n");
#endif
				goto errxit;
			}
			if (!(wtflags & TPWRITE) || (wtflags & TPRANY) ||
			    (wstart() == ERROR))  {
#ifdef DEBUG
				debug("Tpstart: write init error\n"); /* */
#endif
				wtsense(0);

errxit:				bp->b_flags |= B_ERROR;
				bp->b_resid = bp->b_bcount;
				goto xit;
			}
			wtflags |= TPWO|TPWANY;
		} 

		/* and hold your nose */
		if (ucnt1 && ((wtape(adr1, ucnt1) == ERROR)
				&& (wtsense(0) == ERROR)))
			finished = bytes;

		else if (ucnt2 &&
			(((ucnt1 && pollrdy()) ||
				(wtape(adr2, ucnt2) == ERROR)) &&
				(wtsense(0) == ERROR)))
			finished = ucnt1 + NBPS + bytes;
		/* All writes and/or copyins were fine! */
		else
			finished = bp->b_bcount;
		bad = pollrdy();
	}

	endio:
	if(bad == EIO) bad = 0;
	wterror.wt_err = 0;
	if (exflag && wtsense((bp->b_flags & B_READ) ? TP_WRP : 0)) {
		if ((wterror.wt_err & TP_ST0) 
			&& (wterror.wt_err & (TP_FIL|TP_EOM))) {
#ifdef DEBUG
			debug("WTsta: Hit end of tape\n"); /* */
#endif
			wtflags |= TPVOL;
			if (wterror.wt_err & TP_FIL) {
				if (wtflags & TPRO)
					/* interrupter is bogus */
					rstart();  /* restart read command */
				else
					wtflags &= ~TPWO;
				finished += NBPS; 
			}
		/* Reading file marks or writing end of tape return 0 bytes */
		} else	{
			bp->b_flags |= B_ERROR;
			wtflags &= ~(TPWO|TPRO);
		}
	}

	if(bad) {
		bp->b_flags |= B_ERROR;
		bp->b_error = bad;
	}
	bp->b_resid = bp->b_bcount - finished;
xit:
	biodone(bp);
	if (wtimeron)
		Hogtime = lbolt;
	else if (Hogproc == myproc)
		Hogproc = (struct proc *) 0;
}

/*
 * simulate an interrupt periodically while I/O is going
 * this is necessary in case interrupts get eaten due to
 * multiple devices on a single IRQ line
 */
wtimer()
{
	/* If I/O going and not in isr(), simulate interrupt
	 * If no I/O for at least 1 second, stop being a Hog
	 * If I/O done and not a Hog, turn off wtimer()
	 */
	if (wtio && !isrlock)
		isr();

	if ((Hogproc == myproc) && Hogtime && (lbolt-Hogtime > HZ))
		Hogproc = (struct proc *) 0;

	if (wtio || (Hogproc == myproc))
		timeout(wtimer, (caddr_t) 0, HZ);
	else
		wtimeron = 0;
}


wtrawio(bp)
struct buf	*bp;
{
	wtstrategy(bp);
	biowait(bp);
	return(0);
}

wt_minphys(bp)
struct buf	*bp;
{
	if (bp->b_bcount > PAGESIZ)
		bp->b_bcount = PAGESIZ;
}

/*
 * raw read routine
 */
wtread(dev, uio)
struct uio	*uio;
{
	if (wtflags & TPSESS) {
		return(EIO);
	}
	physio(wtrawio, &rwtbuf, dev, B_READ, wt_minphys, uio);
	return(0);
}

/*
 * raw write routine
 */
wtwrite(dev, uio)
struct uio	*uio;
{
	if (wtflags & TPSESS) {
		return(EIO);
	}
	physio(wtrawio, &rwtbuf, dev, B_WRITE, wt_minphys, uio);
	return(0);
}



/*
 * ioctl routine
 *  for user level QIC commands only
 */
wtioctl(dev, cmd, arg, mode)
int dev, cmd;
unsigned long arg;
int mode;
{
	if (cmd == WTQICMD)
	{
		if ((qicmd((int)arg) == ERROR) || (rdyexc(HZ) == ERROR))
		{
			wtsense(0);
			return(EIO);
		}
		return(0);
	}
	return(EINVAL);
}

/*
 * open routine
 * called on every device open
 */
wtopen(dev, flag)
int	dev, flag;
{
	if (first_wtopen_ever) {
		wtinit();
		first_wtopen_ever = 0;
	}
#ifdef DEBUG
	printf("wtopen ...\n");
#endif
	if (!pageaddr) {
		return(ENXIO);
	}
	if (wtflags & (TPINUSE)) {
		return(ENXIO);
	}
	if (wtflags & (TPDEAD)) {
		return(EIO);
	}
	/* If a rewind from the last session is going on, wait */
	while(wtflags & TPREW) {
#ifdef DEBUG
		debug("Waiting for rew to finish\n");
#endif
		delay(1000000);	/* delay one second */
	}
	/* Only do reset and select when tape light is off, and tape is rewound.
	 * This allows multiple volumes. */
	if (wtflags & TPSTART) { 
		if (t_reset() != SUCCESS) {
			return(ENXIO);
		}
#ifdef DEBUG
		debug("reset done. calling wtsense\n");
#endif
		if (wtsense(TP_WRP) == ERROR) {
			return (EIO);
		}
#ifdef DEBUG
		debug("wtsense done\n");
#endif
		wtflags &= ~TPSTART;	
	}

	wtflags = TPINUSE;
	if (flag & FREAD)
		wtflags |= TPREAD;
	if (flag & FWRITE)
		wtflags |= TPWRITE;
	rwtbuf.b_flags = 0;
	myproc = curproc;		/* for comparison */
	switch(TP_DENS(dev)) {