| 1 | /* |
| 2 | * Copyright (c) 1982 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 6.2 (Berkeley) %G% |
| 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 | } |