[unix-history] / usr / src / sys / vax / stand / ht.c

/*
* Copyright (c) 1982 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
*      @(#)ht.c        6.2 (Berkeley) %G%
*/

/*
* TM03/TU?? tape driver
*/
#include "../machine/pte.h"

#include "../h/param.h"
#include "../h/inode.h"
#include "../h/fs.h"

#include "../vaxmba/htreg.h"
#include "../vaxmba/mbareg.h"

#include "saio.h"
#include "savax.h"

short   httypes[] =
       { MBDT_TM03, MBDT_TE16, MBDT_TU45, MBDT_TU77, 0 };

#define MASKREG(reg)    ((reg)&0xffff)

htopen(io)
       register struct iob *io;
{
       register int skip;
       register struct htdevice *htaddr =
          (struct htdevice *)mbadrv(io->i_unit);
       int i;

       for (i = 0; httypes[i]; i++)
               if (httypes[i] == (htaddr->htdt&MBDT_TYPE))
                       goto found;
       _stop("not a tape\n");
found:
       mbainit(UNITTOMBA(io->i_unit));
       htaddr->htcs1 = HT_DCLR|HT_GO;
       htstrategy(io, HT_REW);
       skip = io->i_boff;
       while (skip--) {
               io->i_cc = -1;
               while (htstrategy(io, HT_SFORW))
                       ;
               DELAY(65536);
               htstrategy(io, HT_SENSE);
       }
}

htclose(io)
       register struct iob *io;
{

       htstrategy(io, HT_REW);
}

htstrategy(io, func)
       register struct iob *io;
       int func;
{
       register int den, errcnt, ds;
       int er;
       short fc;
       register struct htdevice *htaddr =
           (struct htdevice *)mbadrv(io->i_unit);

       errcnt = 0;
retry:
       den = HTTC_1600BPI|HTTC_PDP11;
       htquiet(htaddr);
       htaddr->htcs1 = HT_DCLR|HT_GO;
       htaddr->httc = den;
       htaddr->htfc = -io->i_cc;
       if (func == HT_SREV) {
               htaddr->htfc = -1;
               htaddr->htcs1 = HT_SREV|HT_GO;
               return (0);
       }
       if (func == READ || func == WRITE)
               mbastart(io, func);
       else
               htaddr->htcs1 = func|HT_GO;
       htquiet(htaddr);
       ds = htaddr->htds;
       er = htaddr->hter;
       if (ds & HTDS_TM) {
               htaddr->htcs1 = HT_DCLR|HT_GO;
               return (0);
       }
       if (ds & HTDS_ERR) {
               htaddr->htcs1 = HT_DCLR|HT_GO;
               if ((er & HTER_CORCRC) == 0) {
                       printf("ht error: ds=%b, er=%b\n",
                           MASKREG(ds), HTDS_BITS,
                           MASKREG(er), HTER_BITS);
                       if (errcnt == 10) {
                               printf("ht: unrecovered error\n");
                               return (-1);
                       }
                       errcnt++;
                       htstrategy(io, HT_SREV);
                       goto retry;
               }
       }
       if (errcnt)
               printf("ht: recovered by retry\n");
       fc = htaddr->htfc;
       return (io->i_cc+fc);
}

htquiet(htaddr)
       register struct htdevice *htaddr;
{
       register int s;

       do
               s = htaddr->htds;
       while ((s & HTDS_DRY) == 0);
}