scsi_disk.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)scsi_disk.c	4.4  (ULTRIX)        2/21/91";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1984,86,87,88,89 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.			*
 *									*
 *   This software is  derived	from  software	received  from	the	*
 *   University    of	California,   Berkeley,   and	from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is	subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   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.	*
 *									*
 ************************************************************************/

/************************************************************************
 *
 * scsi_disk.c	23-Jun-89
 *
 * VAX SCSI device driver (disk routines)
 *
 * Modification history:
 *
 * 19-Feb-91	Robin Miller
 *   o	Correct race condition in the rzcommand() function by adding the
 *	appropriate spl synchronization.  Previously, if multiple processes
 *	attempted simultaneous access to a drive, processes could be left
 *	in an uninterruptable sleep state.
 *   o	Correct sleep priority when waiting for prior I/O to complete.
 *   o	Catch signals if sleeping at an interruptable priority so buffer
 *	resources can be released and proper error code (EINTR) returned.
 *   o	Remove #ifdef FORMAT conditionalization since we always want this.
 *
 * 11-Sep-90	Robin Miller
 *	Added check in DEVIOCGET ioctl() command for Extra Density (ED)
 *	2.88MB RX26 floppy diskette.  Also set Double Density (DD) flag
 *	appropriately for RX23/RX26 3.5" or RX33 5.25" diskettes.
 *
 * 20-Aug-90	Robin Miller
 *	Set iostat milliseconds per word transfer rate (dk_mspw) for
 *	RX26 in rzopen(), depending on which diskette type (ED/HD/DD)
 *	is loaded in the drive.
 *
 * 09-Aug-90	Robin Miller
 *	Modified check for write protect status for DEVIOCGET ioctl()
 *	so write lock is returned for all CD-ROM's, not just RRD40.
 *
 * 13-Nov-89    Janet Schank
 *      Changed the refrence of nNSCSI to nNSCSIBUS.
 *
 * 29-Oct-89	Fred Canter
 *	Changed the DEVGETGEOM ioctl mode sense code to validate the
 *	page code, i.e., make sure the disk gave us the page we asked for.
 *	One of the non-DEC disks returns page 56 instead of a check
 *	condition when we ask for page 5 (unsupported page for hard disks).
 *
 * 08-Oct-89	Fred Canter
 *	Remove error log #ifdef OLDWAY.
 *
 * 07-Oct-89	Fred Canter
 *	Added DEVGETGEOM ioctl to return disk geometry information.
 *
 * 01-Oct-89	Fred Canter
 *	Fixed a bug in the RX23 SoftPC hooks. Media type ID returned
 *	by DEVIOGET ioctl was incorrect because first read capacity
 *	after unit attention failed (media change).
 *
 *	Bug fix. Disks (except RRD40) were not reporting correct
 *	write locked status via the devioget ioctl.
 *
 * 23-Jul-89	Fred Canter
 *	Convert DBBR printfs to error log calls.
 *	RX33 support.
 *
 * 22-Jul-89	John A. Gallant
 *	Added SCSI_NODBBR flag for disks without BBR.
 *	Added error messages to DBBR code.
 *
 * 16-Jul-89	Fred Canter
 *	Do a mode select to get disk geometry.
 *
 * 23-Jun-89	John A. Gallant
 *	Added the disk command completion routine.  Added the DBBR code.
 *
 * 20-Jun-89	Fred Canter
 *	Convert to scsi_devtab.
 *
 * 11-Jun-89	Fred Canter
 *	Added media changed and density information to devget structure.
 *	So softpc application can make better use of the floppy drive.
 *
 * 08-Jun-89	Fred Canter
 *	Removed RX23 RDCAP hack and handle case where RDCAP can fail if
 *	an unformatted floppy is in the RX23, in rzopen().
 *
 * 06-Jun-89	Fred Canter
 *	Set iostat dk_mspw transfer rate for RX23 in rzopen(), depending
 *	on which type floppy (HD/DD) in loaded in the drive.
 *
 * 24-May-89	Fred Canter
 *	Changes to match the new, more general rzdisk utility.
 *	Changed the mode select data structures so an address and
 *	length are passed with the ioctl. This allows pages to be
 *	added to rzdisk without requiring a kernel rebuild.
 *
 * 06-Apr-89	Fred Canter
 *	Added b_comand to replace b_command for local command buffers.
 *	Use b_gid instead of b_resid to store command.
 *
 * 12-Feb-89	Fred Canter
 *	Added function header comments to each routine.
 *
 * 17-Dec-88	Fred Canter
 *	Added pseudo commands to resolve the conflict between
 *	SZ_UNLOAD and SZ_SSUNIT both being opcode 0x1b.
 *
 * 08-Dec-88	Alan Frechette
 *	Return an error if either of the KMALLOC calls in rzspecial fails.
 *
 * 04-Dec-88	Fred Canter
 *	Changes to rzspecial(). Allow all commands except: format,
 *	reassign block, and read defect data on the CDROM.
 *	Return EROFS instead of ENXIO if command not allowed on CDROM.
 *	Wait 20 seconds in rzopen for CDROM to come on-line (was 10).
 *
 * 03-Nov-88	Alan Frechette
 *	Added in support for disk maintainence. Added the commands
 *	FORMAT UNIT, REASSIGN BLOCK, READ DEFECT DATA, MODE SENSE,
 *	MODE SELECT, INQUIRY and VERIFY DATA. These are all new 
 *	ioctl calls.
 *
 * 16-Oct-88	Fred Canter
 *	Clean up comments.
 *
 * 28-Sep-88	Fred Canter
 *	Clean up copmments. Report DEV_WRTLCK flag with DEVIOCGET ioctl
 *	so RRD40 will return write locked and fsck will be NO WRITE.
 *	Buf fix - rzopen() had a call to tzcommand().
 *
 * 13-Sep-88	Fred Canter
 *	Increased RRD40 retry time to 10 seconds in rzopen to allow
 *	for RRD40 spin up delay, which could take up to 5 seconds.
 *
 * 17-Aug-88	Fred Canter
 *	Created this file by moving the SCSI disk specific files
 *	from the old combined driver (scsi.c) to scsi_disk.c.
 *
 ***********************************************************************/

#include "../data/scsi_data.c"
#include "scsi_debug.h"

/*
 * Disk open routine (need func header)
 */

extern int geterror(), wakeup();
extern int hz;


extern int sz_unit_rcvdiag[];	/* If zero, need unit's selftest status */
extern int sz_retries[];	/* retry counter */

/*
 * Unit on line flag. Set to one if the
 * device is on-line. Set to zero on any unit
 * attention condition.
 */
extern int sz_unit_online[];

/*
 *
 * Name:		rzopen		-Disk open routine
 *
 * Abstract:		This routine is called each time an RZ disk device
 *			is opened. This routine: makes sure the device
 *			exists, checks for device on-line via test unit
 *			ready, does a mode select (lbn size 512), finds
 *			disks size via read capacity, and reads in disk's
 *			partition table.
 *
 * Inputs:
 *
 * dev			ULTRIX major/minor device number.
 * flag			How to open flag (read, write, NDELAY).
 *
 * Outputs:
 *			Possible error messages (eg, device off-line).
 *			sz_unit_online flag set.
 *
 * Return Values:
 *
 * ENXIO		No such device or address (non extistent device).
 * EIO			I/O error (device off-line, could not get size, etc).
 * 0			Open succeeded.
 *
 * Side Effects:
 *			rzcommand() called.
 *			sleep() called.
 *
 */

rzopen(dev, flag)
dev_t dev;
int flag;
{
	register struct uba_device *ui;
	register struct sz_softc *sc;
	int unit = minor(dev) >> 3;
	int cntlr;
	int targid;
	int retry, retrylimit;
	int retval;
	int dev_ready, ssunit_cnt;
	int i;
	struct size *stp;
	struct sz_rdcap_dt *rdp;
	int rzstrategy();

	/*
	 * Order of following checks in important.
	 */
	if (unit >= nNSZ)
	    return(ENXIO);
	ui = szdinfo[unit];
	if ((ui == 0) || (ui->ui_alive == 0))
	    return(ENXIO);
	cntlr = ui->ui_ctlr;
	if (cntlr >= nNSCSIBUS)
	    return(ENXIO);
	targid = ui->ui_slave;
	sc = &sz_softc[cntlr];
	if (sc->sc_alive[targid] == 0)
	    return(ENXIO);
	if (((sc->sc_devtyp[targid] & SZ_DISK) == 0) &&
	    ((sc->sc_devtyp[targid] & SZ_CDROM) == 0))
	    return(ENXIO);
	/*
	 * This is a strange use of the FNDELAY flag.  It
	 * is here to allow the installation finder program
	 * to open the device when the tape cartridge is not
	 * inserted.  The installation finder program needs
	 * to do an ioctl, so open must succeed whether or
	 * not a cartridge is present.
	 */
	/*
	 * Clear sc_flags, device will lockup after any
	 * hard error (DEV_HARDERR set) if we don't.
	 * TODO: other drivers look at dis_eot_??[]!
	 */
	sc->sc_flags[targid] = 0;
	sc->sc_szflags[targid] &= ~SZ_NODEVICE;
	/*
	 * Get selftest result, if we haven't already.
	 * The rz_rcvdiag() routine will return
	 * SZ_NODEVICE if anything is wrong.
	 */
	/*
	 * TODO:
	 *	The RRD40 is the only disk that supports the
	 *	receive diagnostics command. We need to write
	 *	a rz_rcvdiag() routine if we decide to use it.
	 */
/*	if (sz_unit_rcvdiag[unit] == 0)	*/
/*	    sc->sc_szflags[targid] |= rz_rcvdiag(dev);	*/

	/*
	 * Try to bring the drive on line.
	 *
	 * The disks take about 10 seconds to spin up.
	 * They should already be spinning by the time we get here,
	 * but we must make sure the drive is spinning to cover
	 * the remote possibility that it went off line.
	 * We try for 20 seconds to bring the drive on-line.
	 *
	 * The RRD40 comes online almost instantly (about 1 second).
	 * However, it can take 17.9 seconds for error recovery.
	 * So, we try for 20 seconds to bring the drive on-line.
	 * This also allows the user some think time to realize the
	 * CDROM is off-line and load the CD.
	 */
	dev_ready = 0;
	ssunit_cnt = 0;
	retrylimit = 20;
	for (retry = 0; retry < retrylimit; retry++) {
	    if (sc->sc_szflags[targid] & SZ_NODEVICE) {
		if (flag & FNDELAY)
		    break;
		else
		    return(ENXIO);
	    }
	    rzcommand(dev, SZ_TUR, 1, 0);
	    if (sc->sc_c_status[targid] == SZ_GOOD) {
		dev_ready = 1;
		break;
	    }
	    else if (sc->sc_c_status[targid] == SZ_BAD) {
		continue;
	    }
	    else if (sc->sc_c_status[targid] == SZ_CHKCND) {
		retval = SZ_RETRY;
		switch(sc->sc_c_snskey[targid]) {
		case SZ_NOSENSE:
		case SZ_RECOVERR:
		    retval = SZ_SUCCESS;
		    dev_ready = 1;
		    break;

		case SZ_NOTREADY:
		    /*
		     * Send start unit command twice. The first one
		     * could fail due to unit attention.
		     * We don't confuse the issue with error checking!
		     */
		    if (ssunit_cnt < 2) {
			rzcommand(dev, SZ_P_SSUNIT, 1, 0);
			ssunit_cnt++;
		    }
		    timeout(wakeup, (caddr_t)&sc->sc_alive[targid], hz);
		    sleep((caddr_t)&sc->sc_alive[targid], PZERO + 1);
		    if (!(sc->sc_flags[targid] & DEV_EOM)) {
			sc->sc_flags[targid] = 0;
		    }
		    break;

		case SZ_UNITATTEN:
		    sz_unit_online[unit] = 0;
		    /* just retry */
		    break;

		default:
		    /* TODO: may want to retry? */
		    if (!(sc->sc_flags[targid] & DEV_EOM)) {
			sc->sc_flags[targid] = 0;
		    }
		    if(flag & FNDELAY) {
			sc->sc_szflags[targid] |= SZ_NODEVICE;
			retval = SZ_SUCCESS;
		    }
		    else {
			return(ENXIO);
		    }
		    break;
		}	/* end of switch */
		if (retval == SZ_SUCCESS)
		    break;		/* from for loop */
		else
		    continue;		/* with for loop */
	    }
	    else {
		/* TODO: debug */
		printf("rzopen: impossible sc_c_status (val=%d)\n",
		    sc->sc_c_status[targid]);
		continue;	/* retry */
	    }
	}	/* end for loop */
	if (retry >= retrylimit) {
	    if (!(flag & FNDELAY)) {
	    	DEV_UGH(sc->sc_device[targid], unit, "offline");
	    	return(EIO);
	    }
	}
	/*
	 * If SZ_NODEVICE is not set (i.e., the device exists)
	 * and the device is off-line, do a mode select.
	 * This sets the Logical Block Size to 512 bytes.
	 * NOTE: RZ disk drives have 512 bytes as the
	 *	 default LBN size, but we set and check it anyway.
	 * NOTE: production RRD40 drives default to 512 byte lbn size.
	 *	 The RRD40's physical sector size is 2KB.
	 */
	if (!(sc->sc_szflags[targid] & SZ_NODEVICE) &&
	    (sz_unit_online[unit] == 0)) {
	    /*
	     * Use MODSEL to specify 512 byte LBNs.
	     * TODO: later on we may want to change other parameters.
	     */
	    for (retry = 0; retry < 5; retry++) {
		rzcommand(dev, SZ_MODSEL, 1, 0);
		if (sc->sc_c_status[targid] == SZ_GOOD)
		    break;
	    }
	    if ((retry >= 5) && ((flag & FNDELAY) == 0)) {
		printf("rzopen: %s unit %d: mode select failed\n",
		    sc->sc_device[targid], unit);
		return(EIO);
	    }

	    /*
	     * Use RDCAP to determine the size of the disk.
	     * Also verify LBN size is really 512 bytes.
	     * NOTE: CD size depends on how much data was mastered
	     *	     on the CD. Must get size after each media change.
	     * NOTE: RDCAP will fail if the floppy is unformatted.
	     */
	    for (retry = 0; retry < 5; retry++) {
		rzcommand(dev, SZ_RDCAP, 1, 0);
		if (sc->sc_c_status[targid] == SZ_GOOD)
		    break;
	    }
	    if (retry >= 5) {
		sc->sc_disksize[targid] = 0;
		if ((flag & FNDELAY) == 0) {
		    printf("rzopen: %s unit %d: read capacity failed\n",
			sc->sc_device[targid], unit);
		    return(EIO);
		}
	    }
	    else {
		rdp = (struct sz_rdcap_dt *)&sc->sz_dat[targid];
		i = (rdp->lbaddr3 << 24) & 0xff000000;
		i |= (rdp->lbaddr2 << 16) & 0x00ff0000;
		i |= (rdp->lbaddr1 << 8) & 0x0000ff00;
		i |= rdp->lbaddr0 & 0x000000ff;
		/*
		 * RDCAP returns the address of the last LBN.
		 * We must add one to get the number of LBNs.
		 */
		sc->sc_disksize[targid] = (daddr_t)(i + 1);
		/*
		 * Verify LBN size is 512 bytes.
		 */
		i = (rdp->blklen3 << 24) & 0xff000000;
		i |= (rdp->blklen2 << 16) & 0x00ff0000;
		i |= (rdp->blklen1 << 8) & 0x0000ff00;
		i |= rdp->blklen0 & 0x000000ff;
		if (i != 512) {
		    if (!(flag & FNDELAY)) {
			printf("rzopen: %s unit %d: %s (size = %d)\n",
			    sc->sc_device[targid], unit,
			    "could not set LBN size to 512 bytes", i);
			return(EIO);
		    }
		}
	    }
	    /*
	     * Set the milliseconds per word transfer rate for the
	     * RX23/26/33 SCSI floppy depending on the media size.
	     * RX23: If size = 2880 (1.44MB) then the floppy is 18 sector
	     * otherwise assume the floppy is 9 sector.
	     * RX26: If size = 5760 (2.88MB) then the floppy is 36 sector
	     *       If size = 2880 (1.44MB) then the floppy is 18 sector
	     *       otherwise assume the floppy is 9 sector.
	     * RX33: If size = 2400 (1.2MB) then the floppy is 15 sector
	     * otherwise assume the floppy is 10 sector.
	     */
	    if (sc->sc_devtyp[targid] == RX23) {
		if (sc->sc_disksize[targid] == 2880)
		    dk_mspw[ui->ui_dk] = 0.0000434;
		else
		    dk_mspw[ui->ui_dk] = 0.0000868;
	    }
	    if (sc->sc_devtyp[targid] == RX26) {
		if (sc->sc_disksize[targid] == 5760)		/* ED */
		    dk_mspw[ui->ui_dk] = 0.0000217;
		else if (sc->sc_disksize[targid] == 2880)	/* HD */
		    dk_mspw[ui->ui_dk] = 0.0000434;
		else						/* DD */
		    dk_mspw[ui->ui_dk] = 0.0000868;
	    }
	    if (sc->sc_devtyp[targid] == RX33) {
		if (sc->sc_disksize[targid] == 2400)
		    dk_mspw[ui->ui_dk] = 0.0000434;
		else
		    dk_mspw[ui->ui_dk] = 0.0000781;
	    }
	}
	/* NOTE: set for debug, but not used */
	sc->sc_openf[targid] = 1;
	/*
	 *	See if we need to read in the partition table from the disk.
	 *	The conditions we will have to read from the disk is if the
 	 *	partition table valid bit has not been set for the volume
	 *	is invalid.
	 */

	/*
	 *	Assume that the default values before trying to
	 *	see if the partition tables are on the disk. The
	 *	reason that we do this is that the strategy routine
	 *	is used to read in the superblock but uses the 
	 *	partition info.  So we must first assume the
	 *	default values.
	 */

	/* TODO: this looks wrong. If rsblk fails next time
	 * we will think the partition table is good, but
	 * it will be the default pt not the one read from the disk.
	 */
	if ((sz_part[unit].pt_valid == 0) || (sz_unit_online[unit] == 0)) {
		stp = sc->sc_dstp[targid];
		for( i = 0; i < 8; i++ ) {
			sz_part[unit].pt_part[i].pi_nblocks = stp[i].nblocks;
			sz_part[unit].pt_part[i].pi_blkoff = stp[i].blkoffs;
		}

		sz_part[unit].pt_valid = PT_VALID;	

	/*
	 *	Default partition are now set. Call rsblk to set
	 *	the driver's partition tables, if any exists, from
	 *	the "a" partition superblock
	 */