UNIX 7th Ed. - /usr/sys/dev/rl.c

   1: /*
   2:  *  RL disk driver
   3:  */
   4: 
   5: #define DK_N    2
   6: #include "../h/param.h"
   7: #include "../h/buf.h"
   8: #include "../h/dir.h"
   9: #include "../h/user.h"
  10: #include "../h/systm.h"
  11: 
  12: #define NRLBLK 10240
  13: #define RLCYLSZ 10240
  14: #define RLSECSZ 256
  15: 
  16: #define RESET 013
  17: #define STAT 03
  18: #define GETSTAT 04
  19: #define WCOM 012
  20: #define RCOM 014
  21: #define SEEK 06
  22: #define SEEKHI 5
  23: #define SEEKLO 1
  24: #define RDHDR 010
  25: #define IENABLE 0100
  26: #define CRDY 0200
  27: #define OPI 02000
  28: #define CRCERR 04000
  29: #define TIMOUT 010000
  30: #define NXM 020000
  31: #define DE  040000
  32: 
  33: struct device
  34: {
  35:     int rlcs, rlba, rlda, rlmp;
  36: };
  37: 
  38: #define RLADDR  ((struct device *)0174400)
  39: #define RL_CNT 1
  40: struct  buf rrlbuf;
  41: struct  buf rltab;
  42: 
  43: struct
  44: {
  45:     int cn[4];      /* location of heads for each drive */
  46:     int dn;     /* drive number */
  47:     int com;        /* read or write command word */
  48:     int chn;        /* cylinder and head number */
  49:     unsigned int    bleft;  /* bytes left to be transferred */
  50:     unsigned int    bpart;  /* number of bytes transferred */
  51:     int sn;     /* sector number */
  52:     union {
  53:         int w[2];
  54:         long    l;
  55:     } addr;         /* address of memory for transfer */
  56: 
  57: }   rl = {-1,-1,-1,-1};
  58: 
  59: rlstrategy(bp)
  60: register struct buf *bp;
  61: {
  62:     if(bp->b_blkno >= NRLBLK) {
  63:         if(bp->b_blkno == NRLBLK && bp->b_flags&B_READ)
  64:             bp->b_resid = bp->b_bcount;
  65:         else {
  66:             bp->b_flags |= B_ERROR;
  67:             bp->b_error = ENXIO;
  68:         }
  69:         iodone(bp);
  70:         return;
  71:     }
  72:     bp->av_forw = NULL;
  73:     spl5();
  74:     if(rltab.b_actf == NULL)
  75:         rltab.b_actf = bp;
  76:     else
  77:         rltab.b_actl->av_forw = bp;
  78:     rltab.b_actl = bp;
  79:     if(rltab.b_active == NULL)
  80:         rlstart();
  81:     spl0();
  82: }
  83: 
  84: rlstart()
  85: {
  86: 
  87:     register struct buf *bp;
  88: 
  89:     if ((bp = rltab.b_actf) == NULL)
  90:         return;
  91:     rltab.b_active++;
  92:     rl.dn = minor(bp->b_dev);
  93:     rl.chn = bp->b_blkno/20;
  94:     rl.sn = (bp->b_blkno%20) << 1;
  95:     rl.bleft = bp->b_bcount;
  96:     rl.addr.w[0] = bp->b_xmem & 3;
  97:     rl.addr.w[1] = (int)bp->b_un.b_addr;
  98:     rl.com = (rl.dn << 8) | IENABLE;
  99:     if (bp->b_flags & B_READ)
 100:         rl.com |= RCOM;
 101:     else
 102:         rl.com |= WCOM;
 103:     rlio();
 104: }
 105: 
 106: rlintr()
 107: {
 108:     register struct buf *bp;
 109:     register struct device *rp;
 110:     register int status;
 111: 
 112:     rp = RLADDR;
 113:     if (rltab.b_active == NULL) {
 114: /*
 115: 		logstray(rp);
 116: */
 117:         return;
 118:     }
 119:     bp = rltab.b_actf;
 120:     dk_busy &= ~(1<<DK_N);
 121:     if (rp->rlcs < 0) {     /* error bit */
 122:         if (rp->rlcs & 036000) {
 123:             if(rltab.b_errcnt > 2)
 124:                 deverror(bp, rp->rlcs, rp->rlda);
 125:         }
 126:         if (rp->rlcs & 040000) {
 127:             rp->rlda = STAT;
 128:             rp->rlcs = (rl.dn << 8) | GETSTAT;
 129:             while ((rp->rlcs & CRDY) == 0)
 130:                 ;
 131:             status = rp->rlmp;
 132:             if(rltab.b_errcnt > 2)
 133:                 deverror(bp, status, rp->rlda);
 134:             rp->rlda = RESET;
 135:             rp->rlcs = (rl.dn << 8) | GETSTAT;
 136:             while ((rp->rlcs & CRDY) == 0)
 137:                 ;
 138:             if(status & 01000) {
 139:                 rlstart();
 140:                 return;
 141:             }
 142:         }
 143:         if (++rltab.b_errcnt <= 10) {
 144:             rl.cn[rl.dn] = -1;
 145:             rlstart();
 146:             return;
 147:         }
 148:         else {
 149:             bp->b_flags |= B_ERROR;
 150:             rl.bpart = rl.bleft;
 151:         }
 152:     }
 153: 
 154:     if ((rl.bleft -= rl.bpart) > 0) {
 155:         rl.addr.l += rl.bpart;
 156:         rl.sn=0;
 157:         rl.chn++;
 158:         rlio();
 159:         return;
 160:     }
 161:     rltab.b_active = NULL;
 162:     rltab.b_errcnt = 0;
 163:     rltab.b_actf = bp->av_forw;
 164:     bp->b_resid = 0;
 165:     iodone(bp);
 166:     rlstart();
 167: }
 168: 
 169: rlio()
 170: {
 171: 
 172:     register struct device *rp;
 173:     register dif;
 174:     register int head;
 175: 
 176:     rp = RLADDR;
 177:     dk_busy |= 1<<DK_N;
 178:     dk_numb[DK_N] += 1;
 179:     head = rl.bpart>>6;
 180:     dk_wds[DK_N] += head;
 181:     if (rl.cn[rl.dn] < 0) {
 182:         rp->rlcs = (rl.dn << 8) | RDHDR;
 183:         while ((rp->rlcs&CRDY) == 0)
 184:             ;
 185:         rl.cn[rl.dn] = (rp->rlmp&077700) >> 6;
 186:     }
 187:     dif =(rl.cn[rl.dn] >> 1) - (rl.chn >>1);
 188:     head = (rl.chn & 1) << 4;
 189:     if (dif < 0)
 190:         rp->rlda = (-dif <<7) | SEEKHI | head;
 191:     else
 192:         rp->rlda = (dif << 7) | SEEKLO | head;
 193:     rp->rlcs = (rl.dn << 8) | SEEK;
 194:     rl.cn[rl.dn] = rl.chn;
 195:     if (rl.bleft < (rl.bpart = RLCYLSZ - (rl.sn * RLSECSZ)))
 196:         rl.bpart = rl.bleft;
 197:     while ((rp->rlcs&CRDY) == 0)
 198:         ;
 199:     rp->rlda = (rl.chn << 6) | rl.sn;
 200:     rp->rlba = rl.addr.w[1];
 201:     rp->rlmp = -(rl.bpart >> 1);
 202:     rp->rlcs = rl.com | rl.addr.w[0] << 4;
 203: }
 204: 
 205: rlread(dev)
 206: {
 207: 
 208:     physio(rlstrategy, &rrlbuf, dev, B_READ);
 209: }
 210: 
 211: rlwrite(dev)
 212: {
 213: 
 214:     physio(rlstrategy, &rrlbuf, dev, B_WRITE);
 215: }

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