2.11BSD#431 - /usr/src/sys/pdpstand/rx.c

   1: /*
   2:  * RX02 Standalone disk driver.
   3:  * 96/3/8, Steve Schultz (sms@moe.2bsd.com)
   4:  * 95/12/02, Tim Shoppa (shoppa@altair.krl.caltech.edu)
   5:  *
   6:  *	Layout of logical devices:
   7:  *
   8:  *	name	min dev		unit	density
   9:  *	----	-------		----	-------
  10:  *	rx0a	   0		  0	single
  11:  *	rx1a	   1		  1	single
  12:  *	rx0b	   2		  0	double
  13:  *	rx1b	   3		  1	double
  14:  *
  15:  *	the following defines use some fundamental
  16:  *	constants of the RX02.
  17:  */
  18: 
  19: #define NSPB    (4-2*(pn))      /* sectors per block */
  20: #define NRXBLKS (1001-501*(pn)) /* blocks on device */
  21: #define NBPS    (128+128*(pn))  /* bytes per sector */
  22: #define DENSITY ((pn))  /* Density: 0 = single, 1 = double */
  23: #define UNIT    ((dn))  /* Unit Number: 0 = left, 1 = right */
  24: #define RXGD    (RX_GO  | (DENSITY << 8))
  25: 
  26: #define rxwait()    while (((rxaddr->rxcs) & RX_XREQ) == 0)
  27: #define rxdone()    while (((rxaddr->rxcs) & RX_DONE) == 0)
  28: 
  29: #include "../h/param.h"
  30: #include "../pdpuba/rxreg.h"
  31: #include "saio.h"
  32: 
  33: #define NRX 2
  34: 
  35:     struct  rxdevice *RXcsr[NRX+1]=
  36:         {
  37:         (struct rxdevice *)0177170,
  38:         (struct rxdevice *)0,
  39:         (struct rxdevice *)-1
  40:         };
  41: 
  42: rxstrategy(io, func)
  43:     register struct iob *io;
  44: {
  45:     register struct rxdevice *rxaddr;
  46:     daddr_t bn;
  47:     unsigned int sectno,sector,track,dn,pn,bae,lo16,lotemp,cc;
  48:     unsigned int bc,bs,retry;
  49: 
  50:     rxaddr = RXcsr[io->i_ctlr];
  51:     bn = io->i_bn;
  52:     dn = io->i_unit;
  53:     pn = io->i_part;
  54:     cc = io->i_cc;
  55:     iomapadr(io->i_ma, &bae, &lo16);
  56:     bc=0;
  57: 
  58:     for (sectno=0; bc<cc; sectno++) {
  59:         rxfactr((int)bn*NSPB+sectno,&sector,&track);
  60:         if (func == READ) {
  61:                 retry=0;
  62: rxretry:            rxaddr->rxcs=RX_RSECT|RXGD|(UNIT<<4);
  63:                 rxwait();
  64:                 rxaddr->rxsa=sector;
  65:                 rxwait();
  66:                 rxaddr->rxta=track;
  67:                 rxdone();
  68:                 if (rxaddr->rxcs & RX_ERR) {
  69:                 if ((retry++) < 10) goto rxretry;
  70:                     goto rxerr;
  71:                 }
  72:         }
  73:         bs = ((cc-bc<NBPS) ? (cc-bc) : (NBPS));
  74:         rxaddr->rxcs=((func==READ)?RX_EMPTY:RX_FILL)|RXGD|(bae<<12);
  75:         rxwait();
  76:         rxaddr->rxwc=bs/2;
  77:         rxwait();
  78:         rxaddr->rxba=lo16;
  79:         rxdone();
  80:         if (rxaddr->rxcs & RX_ERR) goto rxerr;
  81:         if (func==WRITE) {
  82:             rxaddr->rxcs=RX_WSECT|RXGD|(UNIT<<4);
  83:             rxwait();
  84:             rxaddr->rxsa=sector;
  85:             rxwait();
  86:             rxaddr->rxta=track;
  87:             rxdone();
  88:             if (rxaddr->rxcs & RX_ERR) goto rxerr;
  89:         }
  90:     lotemp=lo16;
  91:     lo16=lo16+NBPS;
  92:     if (lo16 < lotemp)
  93:         bae=bae+1;
  94:     bc=bc+bs;
  95:     }
  96:     return(io->i_cc);
  97: 
  98: rxerr:  printf("%s rxcs %o rxes %o\n",devname(io), rxaddr->rxcs,rxaddr->rxes);
  99:     return(-1);
 100: }
 101: 
 102: 
 103: rxopen(io)
 104:     struct iob *io;
 105: {
 106:     return(genopen(NRX, io));
 107: }
 108: 
 109: /*
 110:  *	rxfactr -- calculates the physical sector and physical
 111:  *	track on the disk for a given logical sector.
 112:  *	call:
 113:  *		rxfactr(logical_sector,&p_sector,&p_track);
 114:  *	the logical sector number (0 - 2001) is converted
 115:  *	to a physical sector number (1 - 26) and a physical
 116:  *	track number (0 - 76).
 117:  *	the logical sectors specify physical sectors that
 118:  *	are interleaved with a factor of 2. thus the sectors
 119:  *	are read in the following order for increasing
 120:  *	logical sector numbers (1,3, ... 23,25,2,4, ... 24,26)
 121:  *	There is also a 6 sector slew between tracks.
 122:  *	Logical sectors start at track 1, sector 1; go to
 123:  *	track 76 and then to track 0.  Thus, for example, unix block number
 124:  *	498 starts at track 0, sector 25 and runs thru track 0, sector 2
 125:  *	(or 6 depending on density).
 126:  */
 127: static
 128: rxfactr(sectr, psectr, ptrck)
 129:     register int sectr;
 130:     int *psectr, *ptrck;
 131: {
 132:     register int p1, p2;
 133: 
 134:     p1 = sectr / 26;
 135:     p2 = sectr % 26;
 136:     /* 2 to 1 interleave */
 137:     p2 = (2 * p2 + (p2 >= 13 ?  1 : 0)) % 26;
 138:     /* 6 sector per track slew */
 139:     *psectr = 1 + (p2 + 6 * p1) % 26;
 140:     if (++p1 >= 77)
 141:         p1 = 0;
 142:     *ptrck = p1;
 143: }

Defined functions

Defined variables

Defined macros