BSD 4_1_snap development

[unix-history] / sys / stand / mt.c

/*      mt.c    4.1     81/12/01        */

/*
* TM78/TU78 tape driver
*/

#include "../h/mtreg.h"
#include "../h/param.h"
#include "../h/inode.h"
#include "../h/pte.h"
#include "../h/mbareg.h"
#include "saio.h"
#include "savax.h"

short   mttypes[] =
       { MBDT_TU78, 0 };

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

mtopen(io)
       register struct iob *io;
{
       register int skip;
       register struct mtdevice *mtaddr = (struct mtdevice *)mbadrv(io->i_unit);
       int i;

       for (i = 0; mttypes[i]; i++)
               if (mttypes[i] == (mtaddr->mtdt&MBDT_TYPE))
                       goto found;
       _stop("not a tape\n");
found:
       mbainit(UNITTOMBA(io->i_unit));
       mtaddr->mtid = MTID_CLR;
       DELAY(250);
       while ((mtaddr->mtid & MTID_RDY) == 0)
               ;
       mtstrategy(io, MT_REW);
       skip = io->i_boff;
       while (skip--) {
               io->i_cc = -1;
               mtstrategy(io, MT_SFORWF);
       }
}

mtclose(io)
       register struct iob *io;
{

       mtstrategy(io, MT_REW);
}

mtstrategy(io, func)
       register struct iob *io;
       int func;
{
       register int errcnt, s, ic;
       register struct mtdevice *mtaddr =
           (struct mtdevice *)mbadrv(io->i_unit);

       errcnt = 0;
retry:
       if (func == READ || func == WRITE) {
               mtaddr->mtca = 1<<2;    /* 1 record */
               mtaddr->mtbc = io->i_cc;
               mtaddr->mter = 0;
               mbastart(io, func);
               do
                       s = mtaddr->mter & MTER_INTCODE;
               while (s == 0);
               ic = s;
               DELAY(2000);
       } else {
               mtaddr->mtas = -1;
               mtaddr->mtncs[0] = (-io->i_cc << 8)|func|MT_GO;
       rwait:
               do
                       s = mtaddr->mtas&0xffff;
               while (s == 0);
               mtaddr->mtas = mtaddr->mtas;    /* clear attention */
               ic = mtaddr->mtner & MTER_INTCODE;
       }
       switch (ic) {
       case MTER_TM:
       case MTER_EOT:
       case MTER_LEOT:
               return (0);

       case MTER_DONE:
               break;

       case MTER_RWDING:
               goto rwait;
       default:
               printf("mt hard error: er=%b\n",
                   MASKREG(mtaddr->mter));
               mtaddr->mtid = MTID_CLR;
               DELAY(250);
               while ((mtaddr->mtid & MTID_RDY) == 0)
                       ;
               return (-1);

       case MTER_RETRY:
               printf("mt error: er=%b\n",
                   MASKREG(mtaddr->mter));
               if (errcnt == 10) {
                       printf("mt: unrecovered error\n");
                       return (-1);
               }
               errcnt++;
               goto retry;
       }
       if (errcnt)
               printf("mt: recovered by retry\n");
       return (io->i_cc);      /* NO PARTIAL RECORD READS!!! */
}