4.3BSD - /usr/src/sys/stand/mt.c

   1: /*
   2:  * Copyright (c) 1982, 1986 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  *
   6:  *	@(#)mt.c	7.1 (Berkeley) 6/5/86
   7:  */
   8: 
   9: /*
  10:  * TM78/TU78 tape driver
  11:  * Made to work reliably by by Jeffrey R. Schwab (Purdue)
  12:  */
  13: #include "../machine/pte.h"
  14: 
  15: #include "../h/param.h"
  16: #include "../h/inode.h"
  17: #include "../h/fs.h"
  18: 
  19: #include "../vaxmba/mtreg.h"
  20: #include "../vaxmba/mbareg.h"
  21: 
  22: #include "saio.h"
  23: #include "savax.h"
  24: 
  25: short   mttypes[] =
  26:     { MBDT_TU78, 0 };
  27: 
  28: #define MASKREG(reg)    ((reg)&0xffff)
  29: 
  30: mtopen(io)
  31:     register struct iob *io;
  32: {
  33:     register int skip;
  34:     register struct mtdevice *mtaddr =
  35:         (struct mtdevice *)mbadrv(io->i_unit);
  36:     int i;
  37: 
  38:     for (i = 0; mttypes[i]; i++)
  39:         if (mttypes[i] == (mtaddr->mtdt&MBDT_TYPE))
  40:             goto found;
  41:     _stop("not a tape\n");
  42: found:
  43:     mbainit(UNITTOMBA(io->i_unit));
  44:     mtaddr->mtid = MTID_CLR;
  45:     DELAY(250);
  46:     while ((mtaddr->mtid & MTID_RDY) == 0)
  47:         ;
  48: 
  49:     /* clear any attention bits present on open */
  50:     i = mtaddr->mtner;
  51:     mtaddr->mtas = mtaddr->mtas;
  52: 
  53:     mtstrategy(io, MT_REW);
  54:     skip = io->i_boff;
  55:     while (skip--) {
  56:         io->i_cc = -1;
  57:         mtstrategy(io, MT_SFORWF);
  58:     }
  59: }
  60: 
  61: mtclose(io)
  62:     register struct iob *io;
  63: {
  64: 
  65:     mtstrategy(io, MT_REW);
  66: }
  67: 
  68: mtstrategy(io, func)
  69:     register struct iob *io;
  70:     int func;
  71: {
  72:     register int errcnt, s, ic;
  73:     register struct mtdevice *mtaddr =
  74:         (struct mtdevice *)mbadrv(io->i_unit);
  75:     struct mba_regs *mba = mbamba(io->i_unit);
  76: 
  77:     errcnt = 0;
  78: retry:
  79:     /* code to trap for attention up prior to start of command */
  80:     if ((mtaddr->mtas & 0xffff) != 0) {
  81:         printf("mt unexpected attention er=%x - continuing\n",
  82:             MASKREG(mtaddr->mtner));
  83:         mtaddr->mtas = mtaddr->mtas;
  84:     }
  85: 
  86:     if (func == READ || func == WRITE) {
  87:         mtaddr->mtca = 1<<2;    /* 1 record */
  88:         mtaddr->mtbc = io->i_cc;
  89:         mbastart(io, func);
  90:         /* wait for mba to go idle and read result status */
  91:         while((mba->mba_sr & MBSR_DTBUSY) != 0)
  92:             ;
  93:         ic = mtaddr->mter & MTER_INTCODE;
  94:     } else {
  95:         mtaddr->mtncs[0] = (-io->i_cc << 8)|func|MT_GO;
  96:     rwait:
  97:         do
  98:             s = mtaddr->mtas&0xffff;
  99:         while (s == 0);
 100:         ic = mtaddr->mtner & MTER_INTCODE;
 101:         mtaddr->mtas = mtaddr->mtas;    /* clear attention */
 102:     }
 103:     switch (ic) {
 104:     case MTER_TM:
 105:     case MTER_EOT:
 106:     case MTER_LEOT:
 107:         return (0);
 108: 
 109:     case MTER_DONE:
 110:         /* make sure a record was read */
 111:         if ((mtaddr->mtca & (1 << 2)) != 0) {
 112:             printf("mt record count not decremented - retrying\n");
 113:             goto retry;
 114:         }
 115:         break;
 116: 
 117:     case MTER_RWDING:
 118:         goto rwait;
 119:     default:
 120:         printf("mt hard error: er=%x\n",
 121:             MASKREG(mtaddr->mter));
 122:         mtaddr->mtid = MTID_CLR;
 123:         DELAY(250);
 124:         while ((mtaddr->mtid & MTID_RDY) == 0)
 125:             ;
 126:         return (-1);
 127: 
 128:     case MTER_RETRY:
 129:         printf("mt error: er=%x\n", MASKREG(mtaddr->mter));
 130:         if (errcnt == 10) {
 131:             printf("mt: unrecovered error\n");
 132:             return (-1);
 133:         }
 134:         errcnt++;
 135:         goto retry;
 136:     }
 137:     if (errcnt)
 138:         printf("mt: recovered by retry\n");
 139:     return (io->i_cc);  /* NO PARTIAL RECORD READS!!! */
 140: }

Defined functions

Defined variables

Defined macros