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Annotation of 43BSDTahoe/sys/vaxstand/mt.c, revision 1.1.1.1

1.1       root        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        7.3 (Berkeley) 2/22/88
                      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 "param.h"
                     16: #include "inode.h"
                     17: #include "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 struct mtdevice *mtaddr;
                     34:        register int i, skip;
                     35: 
                     36:        if (mbainit(io->i_adapt) == 0)
                     37:                return (EADAPT);
                     38:        mtaddr = (struct mtdevice *)mbadrv(io->i_adapt, io->i_ctlr);
                     39:        for (i = 0;; i++) {
                     40:                if (!mttypes[i]) {
                     41:                        printf("mt: not a tape\n");
                     42:                        return (ENXIO);
                     43:                }
                     44:                if (mttypes[i] == (mtaddr->mtdt&MBDT_TYPE))
                     45:                        break;
                     46:        }
                     47:        mtaddr->mtid = MTID_CLR;
                     48:        DELAY(250);
                     49:        while ((mtaddr->mtid & MTID_RDY) == 0);
                     50: 
                     51:        /* clear any attention bits present on open */
                     52:        i = mtaddr->mtner;
                     53:        mtaddr->mtas = mtaddr->mtas;
                     54: 
                     55:        mtstrategy(io, MT_REW);
                     56:        for (skip = io->i_part; skip--;) {
                     57:                io->i_cc = -1;
                     58:                mtstrategy(io, MT_SFORWF);
                     59:        }
                     60:        return (0);
                     61: }
                     62: 
                     63: mtclose(io)
                     64:        register struct iob *io;
                     65: {
                     66:        mtstrategy(io, MT_REW);
                     67: }
                     68: 
                     69: mtstrategy(io, func)
                     70:        register struct iob *io;
                     71:        int func;
                     72: {
                     73:        register int errcnt, s, ic;
                     74:        register struct mtdevice *mtaddr;
                     75:        struct mba_regs *mba;
                     76: 
                     77:        errcnt = 0;
                     78:        mtaddr = (struct mtdevice *)mbadrv(io->i_adapt, io->i_ctlr);
                     79:        mba = mbamba(io->i_adapt);
                     80: retry:
                     81:        /* code to trap for attention up prior to start of command */
                     82:        if ((mtaddr->mtas & 0xffff) != 0) {
                     83:                printf("mt unexpected attention er=%x - continuing\n",
                     84:                        MASKREG(mtaddr->mtner));
                     85:                mtaddr->mtas = mtaddr->mtas;
                     86:        }
                     87: 
                     88:        if (func == READ || func == WRITE) {
                     89:                mtaddr->mtca = 1<<2;    /* 1 record */
                     90:                mtaddr->mtbc = io->i_cc;
                     91:                mbastart(io, io->i_ctlr, func);
                     92:                /* wait for mba to go idle and read result status */
                     93:                while((mba->mba_sr & MBSR_DTBUSY) != 0)
                     94:                        ;
                     95:                ic = mtaddr->mter & MTER_INTCODE;
                     96:        } else {
                     97:                mtaddr->mtncs[0] = (-io->i_cc << 8)|func|MT_GO;
                     98:        rwait:
                     99:                do
                    100:                        s = mtaddr->mtas&0xffff;
                    101:                while (s == 0);
                    102:                ic = mtaddr->mtner & MTER_INTCODE;
                    103:                mtaddr->mtas = mtaddr->mtas;    /* clear attention */
                    104:        }
                    105:        switch (ic) {
                    106:        case MTER_TM:
                    107:        case MTER_EOT:
                    108:        case MTER_LEOT:
                    109:                return (0);
                    110: 
                    111:        case MTER_DONE:
                    112:                /* make sure a record was read */
                    113:                if ((mtaddr->mtca & (1 << 2)) != 0) {
                    114:                        printf("mt record count not decremented - retrying\n");
                    115:                        goto retry;
                    116:                }
                    117:                break;
                    118: 
                    119:        case MTER_RWDING:
                    120:                goto rwait;
                    121:        default:
                    122:                printf("mt hard error: er=%x\n",
                    123:                    MASKREG(mtaddr->mter));
                    124:                mtaddr->mtid = MTID_CLR;
                    125:                DELAY(250);
                    126:                while ((mtaddr->mtid & MTID_RDY) == 0)
                    127:                        ;
                    128:                return (-1);
                    129: 
                    130:        case MTER_RETRY:
                    131:                printf("mt error: er=%x\n", MASKREG(mtaddr->mter));
                    132:                if (errcnt++ == 10) {
                    133:                        printf("mt: unrecovered error\n");
                    134:                        return (-1);
                    135:                }
                    136:                goto retry;
                    137:        }
                    138:        if (errcnt)
                    139:                printf("mt: recovered by retry\n");
                    140:        return (io->i_cc);      /* NO PARTIAL RECORD READS!!! */
                    141: }

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