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

/*
* Copyright (c) 1982, 1986, 1988 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
*      @(#)ut.c        7.5 (Berkeley) %G%
*/

/*
* SI Model 9700 -- emulates TU45 on the UNIBUS
*/

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

#include "../vax/pte.h"

#include "../vaxuba/ubareg.h"
#include "../vaxuba/utreg.h"

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

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

#define MAXCTLR         1               /* all addresses must be specified */
u_short utstd[MAXCTLR] = { 0172440 };   /* non-standard */

utopen(io)
       register struct iob *io;
{
       register int skip;

       if ((u_int)io->i_adapt >= nuba)
               return (EADAPT);
       if ((u_int)io->i_ctlr >= MAXCTLR)
               return (ECTLR);
       if (badaddr((char *)ubamem(io->i_unit, utstd[io->i_ctlr]), sizeof(short)))
               return (ENXIO);
       utstrategy(io, UT_REW);
       for (skip = io->i_part; skip--;)
               utstrategy(io, UT_SFORWF);
       return (0);
}

utclose(io)
       register struct iob *io;
{
       utstrategy(io, UT_REW);
}

#define UTWAIT(addr) { \
       do \
               word = addr->utcs1; \
       while((word&UT_RDY) == 0); \
}

utstrategy(io, func)
       register struct iob *io;
{
       register struct utdevice *addr;
       register u_short word;
       register int errcnt;
       int info, resid;
       u_short dens;

       addr = (struct utdevice *)ubamem(io->i_unit, utstd[io->i_ctlr]);
       dens = io->i_unit | PDP11FMT | UT_PE;
       errcnt = 0;
retry:
       utquiet(addr);
       addr->uttc = dens;
       info = ubasetup(io, 1);
       addr->utwc = -((io->i_cc+1) >> 1);
       addr->utfc = -io->i_cc;
       if (func == READ) {
               addr->utba = info;
               addr->utcs1 = UT_RCOM | ((info>>8) & 0x30) | UT_GO;
       } else if (func == WRITE) {
               addr->utba = info;
               addr->utcs1 = UT_WCOM | ((info>>8) & 0x30) | UT_GO;
       } else if (func == UT_SREV) {
               addr->utcs1 = UT_SREV | UT_GO;
               return (0);
       } else
               addr->utcs1 = func | UT_GO;
       UTWAIT(addr);
       ubafree(io, info);
       word = addr->utds;
       if (word&(UTDS_EOT|UTDS_TM)) {
               addr->utcs1 = UT_CLEAR | UT_GO;
               goto done;
       }
       if ((word&UTDS_ERR) || (addr->utcs1&UT_TRE)) {
               printf("ut error: cs1=%b er=%b cs2=%b ds=%b",
                 addr->utcs1, UT_BITS, addr->uter, UTER_BITS,
                 addr->utcs2, UTCS2_BITS, word, UTDS_BITS);
               if (errcnt++ == 10) {
                       printf("ut: unrecovered error\n");
                       return (-1);
               }
               if (addr->utcs1&UT_TRE)
                       addr->utcs2 |= UTCS2_CLR;
               addr->utcs1 = UT_CLEAR | UT_GO;
               utstrategy(io, UT_SREV);
               utquiet(addr);
               if (func == WRITE) {
                       addr->utcs1 = UT_ERASE | UT_GO;
                       UTWAIT(addr);
               }
               goto retry;
       }
       if (errcnt)
               printf("ut: recovered by retry\n");
done:
       if (func == READ) {
               resid = 0;
               if (io->i_cc > MASKREG(addr->utfc))
                       resid = io->i_cc - MASKREG(addr->utfc);
       } else
               resid = MASKREG(-addr->utfc);
       return (io->i_cc - resid);
}

static
utquiet(addr)
       register struct utdevice *addr;
{
       register u_short word;

       UTWAIT(addr);
       do
               word = addr->utds;
       while ((word&UTDS_DRY) == 0 && (word&UTDS_PIP));
}