seagate.c

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#endif

/*
 *    The target will drop SEL, and raise BSY, at which time we must drop
 *      BSY.
 */

      ULOOP( 100*1000 ) {
	if (!(STATUS & STAT_SEL)) break;
	if (TIMEOUT) {
	  WRITE_CONTROL (BASE_CMD | CMD_INTR);
	  DPRINTK (PHASE_RESELECT,
		   "scsi%d : RESELECT timed out while waiting for SEL.\n", hostno);
	  return (DID_BAD_INTR << 16);
	}
      }

      WRITE_CONTROL (BASE_CMD);

/*
 *    At this point, we have connected with the target and can get
 *      on with our lives.
 */
      break;
    case CAN_RECONNECT:

#ifdef LINKED
/*
 * This is a bletcherous hack, just as bad as the Unix #! interpreter stuff.
 * If it turns out we are using the wrong I_T_L nexus, the easiest way to deal
 * with it is to go into our INFORMATION TRANSFER PHASE code, send a ABORT
 * message on MESSAGE OUT phase, and then loop back to here.
 */

    connect_loop:

#endif

      DPRINTK (PHASE_BUS_FREE, "scsi%d : phase = BUS FREE \n", hostno);

/*
 *    BUS FREE PHASE
 *
 *      On entry, we make sure that the BUS is in a BUS FREE
 *      phase, by insuring that both BSY and SEL are low for
 *      at least one bus settle delay.  Several reads help
 *      eliminate wire glitch.
 */

#ifndef ARBITRATE
#error FIXME: this is broken: we may not use jiffies here - we are under cli(). It will hardlock.
      clock = jiffies + ST0X_BUS_FREE_DELAY;

      while (((STATUS | STATUS | STATUS) &
              (STAT_BSY | STAT_SEL)) &&
             (!st0x_aborted) && time_before(jiffies, clock));

      if (time_after(jiffies, clock))
        return retcode (DID_BUS_BUSY);
      else if (st0x_aborted)
        return retcode (st0x_aborted);
#endif

      DPRINTK (PHASE_SELECTION, "scsi%d : phase = SELECTION\n", hostno);

      clock = jiffies + ST0X_SELECTION_DELAY;

/*
 * Arbitration/selection procedure :
 * 1.  Disable drivers
 * 2.  Write HOST adapter address bit
 * 3.  Set start arbitration.
 * 4.  We get either ARBITRATION COMPLETE or SELECT at this
 *     point.
 * 5.  OR our ID and targets on bus.
 * 6.  Enable SCSI drivers and asserted SEL and ATTN
 */

#ifdef ARBITRATE
      save_flags (flags);
      cli ();
      WRITE_CONTROL (0);
      WRITE_DATA ((controller_type == SEAGATE) ? 0x80 : 0x40);
      WRITE_CONTROL (CMD_START_ARB);
      restore_flags (flags);

      ULOOP( ST0X_SELECTION_DELAY * 10000 ) {
	status_read = STATUS;
	if (status_read & STAT_ARB_CMPL) break;
	if (st0x_aborted)	/* FIXME: What? We are going to do something even after abort? */
	   break;
	if (TIMEOUT || (status_read & STAT_SEL)) {
	  printk( "scsi%d : arbitration lost or timeout.\n", hostno );
	  WRITE_CONTROL (BASE_CMD);
	  return retcode (DID_NO_CONNECT);
	}
      }

      DPRINTK (PHASE_SELECTION, "scsi%d : arbitration complete\n", hostno);
#endif

/*
 *    When the SCSI device decides that we're gawking at it, it will
 *    respond by asserting BUSY on the bus.
 *
 *    Note : the Seagate ST-01/02 product manual says that we should
 *    twiddle the DATA register before the control register.    However,
 *    this does not work reliably so we do it the other way around.
 *
 *    Probably could be a problem with arbitration too, we really should
 *    try this with a SCSI protocol or logic analyzer to see what is
 *    going on.
 */
       tmp_data = (unsigned char) ((1 << target) | (controller_type == SEAGATE ? 0x80 : 0x40));
       tmp_control = BASE_CMD | CMD_DRVR_ENABLE | CMD_SEL | (reselect ? CMD_ATTN : 0);

       save_flags(flags);
       cli();
#ifdef OLDCNTDATASCEME
#ifdef SWAPCNTDATA
       WRITE_CONTROL (tmp_control);
       WRITE_DATA (tmp_data);
#else
       WRITE_DATA (tmp_data);
       WRITE_CONTROL (tmp_control);
#endif
#else
       tmp_control ^= CMD_BSY;		/* This is guesswork. What used to be in driver	   */
       WRITE_CONTROL (tmp_control);	/* could never work: it sent data into control	   */
       WRITE_DATA (tmp_data);		/* register and control info into data. Hopefully  */
       tmp_control ^= CMD_BSY;		/* fixed, but order of first two may be wrong.     */
       WRITE_CONTROL (tmp_control);	                              /* -- [e-mail]   */
#endif       


       restore_flags (flags);

       ULOOP( 250*1000 ) {
	 if (st0x_aborted) {
/*
 *    If we have been aborted, and we have a command in progress, IE the
 *      target still has BSY asserted, then we will reset the bus, and
 *      notify the midlevel driver to expect sense.
 */

	   WRITE_CONTROL (BASE_CMD);
	   if (STATUS & STAT_BSY) {
	     printk ("scsi%d : BST asserted after we've been aborted.\n", hostno);
	     seagate_st0x_reset (NULL, 0);
	     return retcode (DID_RESET);
	   }
	   return retcode (st0x_aborted);
	 }
	 if (STATUS & STAT_BSY) break;
	 if (TIMEOUT) {
	   DPRINTK (PHASE_SELECTION, "scsi%d : NO CONNECT with target %d, stat = %x \n",
		    hostno, target, STATUS);
	   return retcode (DID_NO_CONNECT);
	 }
       }

/* Establish current pointers.  Take into account scatter / gather */

      if ((nobuffs = SCint->use_sg))
      {
#if (DEBUG & DEBUG_SG)
        {
          int i;

          printk ("scsi%d : scatter gather requested, using %d buffers.\n",
                  hostno, nobuffs);
          for (i = 0; i < nobuffs; ++i)
            printk ("scsi%d : buffer %d address = %08x length = %d\n",
                    hostno, i, buffer[i].address, buffer[i].length);
        }
#endif

        buffer = (struct scatterlist *) SCint->buffer;
        len = buffer->length;
        data = (unsigned char *) buffer->address;
      }
      else
      {
        DPRINTK (DEBUG_SG, "scsi%d : scatter gather not requested.\n", hostno);
        buffer = NULL;
        len = SCint->request_bufflen;
        data = (unsigned char *) SCint->request_buffer;
      }

      DPRINTK (PHASE_DATAIN | PHASE_DATAOUT, "scsi%d : len = %d\n", hostno, len);

      break;
#ifdef LINKED
    case LINKED_RIGHT:
      break;
    case LINKED_WRONG:
      break;
#endif
  }                                     /* end of switch(reselect) */

/*
 *    There are several conditions under which we wish to send a message :
 *      1.  When we are allowing disconnect / reconnect, and need to establish
 *          the I_T_L nexus via an IDENTIFY with the DiscPriv bit set.
 *
 *      2.  When we are doing linked commands, are have the wrong I_T_L nexus
 *          established and want to send an ABORT message.
 */

/* GCC does not like an ifdef inside a macro, so do it the hard way. */
#ifdef LINKED
  WRITE_CONTROL (BASE_CMD | CMD_DRVR_ENABLE |
                 (((reselect == CAN_RECONNECT)
                   || (reselect == LINKED_WRONG)
                  )? CMD_ATTN : 0));
#else
  WRITE_CONTROL (BASE_CMD | CMD_DRVR_ENABLE |
                 (((reselect == CAN_RECONNECT)
                  )? CMD_ATTN : 0));
#endif

/*
 *    INFORMATION TRANSFER PHASE
 *
 *      The nasty looking read / write inline assembler loops we use for
 *      DATAIN and DATAOUT phases are approximately 4-5 times as fast as
 *      the 'C' versions - since we're moving 1024 bytes of data, this
 *      really adds up.
 *
 *      SJT: The nasty-looking assembler is gone, so it's slower.
 *
 */

  DPRINTK (PHASE_ETC, "scsi%d : phase = INFORMATION TRANSFER\n", hostno);

  incommand = 1;
  transfersize = SCint->transfersize;
  underflow = SCint->underflow;

/*
 *    Now, we poll the device for status information,
 *      and handle any requests it makes.  Note that since we are unsure of
 *      how much data will be flowing across the system, etc and cannot
 *      make reasonable timeouts, that we will instead have the midlevel
 *      driver handle any timeouts that occur in this phase.
 */

  while (((status_read = STATUS) & STAT_BSY) && !st0x_aborted && !done)
  {
#ifdef PARITY
    if (status_read & STAT_PARITY)
    {
      printk ("scsi%d : got parity error\n", hostno);
      st0x_aborted = DID_PARITY;
    }
#endif

    if (status_read & STAT_REQ)
    {
#if ((DEBUG & PHASE_ETC) == PHASE_ETC)
      if ((newphase = (status_read & REQ_MASK)) != phase)
      {
        phase = newphase;
        switch (phase)
        {
          case REQ_DATAOUT:
            printk ("scsi%d : phase = DATA OUT\n", hostno);
            break;
          case REQ_DATAIN:
            printk ("scsi%d : phase = DATA IN\n", hostno);
            break;
          case REQ_CMDOUT:
            printk ("scsi%d : phase = COMMAND OUT\n", hostno);
            break;
          case REQ_STATIN:
            printk ("scsi%d : phase = STATUS IN\n", hostno);
            break;
          case REQ_MSGOUT:
            printk ("scsi%d : phase = MESSAGE OUT\n", hostno);
            break;
          case REQ_MSGIN:
            printk ("scsi%d : phase = MESSAGE IN\n", hostno);
            break;
          default:
            printk ("scsi%d : phase = UNKNOWN\n", hostno);
            st0x_aborted = DID_ERROR;
        }
      }
#endif
      switch (status_read & REQ_MASK)
      {
        case REQ_DATAOUT:
/*
 * If we are in fast mode, then we simply splat the data out
 * in word-sized chunks as fast as we can.
 */

          if (!len)
          {
#if 0
            printk ("scsi%d: underflow to target %d lun %d \n", hostno, target, lun);
            st0x_aborted = DID_ERROR;
            fast = 0;
#endif
            break;
          }

          if (fast && transfersize && !(len % transfersize)
              && (len >= transfersize)
#ifdef FAST32
              && !(transfersize % 4)
#endif
            )
          {
            DPRINTK (DEBUG_FAST,
		     "scsi%d : FAST transfer, underflow = %d, transfersize = %d\n"
                    "         len = %d, data = %08x\n",
                  hostno, SCint->underflow, SCint->transfersize, len, data);

/* SJT: Start. Fast Write */
#ifdef SEAGATE_USE_ASM
            __asm__(
                "cld\n\t"
#ifdef FAST32
                "shr $2, %%ecx\n\t"
                "1:\t"
                "lodsl\n\t"
                "movl %%eax, (%%edi)\n\t"
#else
                "1:\t"
                "lodsb\n\t"
                "movb %%al, (%%edi)\n\t"
#endif
                "loop 1b;"
/* output */    :
/* input */     : "D" (phys_to_virt(st0x_dr)), "S" (data), "c" (SCint->transfersize) 
/* clobbered */ : "eax", "ecx", "esi" );
#else /* SEAGATE_USE_ASM */
            {
#ifdef FAST32
              unsigned int *iop = phys_to_virt (st0x_dr);
              const unsigned int *dp = (unsigned int *) data;
              int xferlen = transfersize >> 2;
#else
              unsigned char *iop = phys_to_virt (st0x_dr);
              const unsigned char *dp = data;
              int xferlen = transfersize;
#endif
              for (; xferlen; --xferlen)
                *iop = *dp++;
            }
#endif /* SEAGATE_USE_ASM */
/* SJT: End */
            len -= transfersize;
            data += transfersize;
            DPRINTK (DEBUG_FAST,
		     "scsi%d : FAST transfer complete len = %d data = %08x\n",
                    hostno, len, data);
          }
          else
          {
/*
 *    We loop as long as we are in a data out phase, there is data to send,
 *      and BSY is still active.
 */

/* SJT: Start. Slow Write. */
#ifdef SEAGATE_USE_ASM

int __dummy_1,__dummy_2;

/*
 *      We loop as long as we are in a data out phase, there is data to send, 
 *      and BSY is still active.
 */
/* Local variables : len = ecx , data = esi, 
                     st0x_cr_sr = ebx, st0x_dr =  edi
*/
            __asm__ (
            /* Test for any data here at all. */
                    "orl %%ecx, %%ecx\n\t"
                    "jz 2f\n\t"
                    "cld\n\t"
/*                    "movl " SYMBOL_NAME_STR(st0x_cr_sr) ", %%ebx\n\t"  */
/*                    "movl " SYMBOL_NAME_STR(st0x_dr) ", %%edi\n\t"  */
                "1:\t"
                    "movb (%%ebx), %%al\n\t"
            /* Test for BSY */
                    "test $1, %%al\n\t"
                    "jz 2f\n\t"
            /* Test for data out phase - STATUS & REQ_MASK should be 
               REQ_DATAOUT, which is 0. */
                    "test $0xe, %%al\n\t"
                    "jnz 2f\n\t"
            /* Test for REQ */      
                    "test $0x10, %%al\n\t"
                    "jz 1b\n\t"
                    "lodsb\n\t"
                    "movb %%al, (%%edi)\n\t"
                    "loop 1b\n\t"
                "2:\n"
/* output */    : "=S" (data), "=c" (len)  ,"=b" (__dummy_1) ,"=D" (__dummy_2)
/* input */     : "0" (data), "1" (len), "2" (phys_to_virt(st0x_cr_sr)), "3" (phys_to_virt(st0x_dr)) 
/* clobbered */ : "eax"); 
#else /* SEAGATE_USE_ASM */
            while (len)
            {
              unsigned char stat;

              stat = STATUS;
              if (!(stat & STAT_BSY) || ((stat & REQ_MASK) != REQ_DATAOUT))
                break;
              if (stat & STAT_REQ)
              {
                WRITE_DATA (*data++);
                --len;
              }
            }
#endif /* SEAGATE_USE_ASM */
/* SJT: End. */
          }

          if (!len && nobuffs)
          {
            --nobuffs;
            ++buffer;
            len = buffer->length;
            data = (unsigned char *) buffer->address;
            DPRINTK (DEBUG_SG,
		    "scsi%d : next scatter-gather buffer len = %d address = %08x\n",