scsiiom.c

Linux内核源代码 为压缩文件 是<<Linux内核>>一书中的源代码

	    else
		pSRB->SGToBeXferLen = 0;
	}
	else	/* phase changed */
	{
	    residual = 0;
	    bval = DC390_read8 (Current_Fifo);
	    while( bval & 0x1f )
	    {
		DEBUG1(printk (KERN_DEBUG "Check for residuals,");)
		if( (bval & 0x1f) == 1 )
		{
		    for(i=0; i < 0x100; i++)
		    {
			bval = DC390_read8 (Current_Fifo);
			if( !(bval & 0x1f) )
			    goto din_1;
			else if( i == 0x0ff )
			{
			    residual = 1;   /* ;1 residual byte */
			    goto din_1;
			}
		    }
		}
		else
		    bval = DC390_read8 (Current_Fifo);
	    }
din_1:
	    DC390_write8 (DMA_Cmd, READ_DIRECTION+DMA_BLAST_CMD);
	    for (i = 0xa000; i; i--)
	    {
		bval = DC390_read8 (DMA_Status);
		if (bval & BLAST_COMPLETE)
		    break;
	    }
	    /* It seems a DMA Blast abort isn't that bad ... */
	    if (!i) printk (KERN_ERR "DC390: DMA Blast aborted unfinished!\n");
	    //DC390_write8 (DMA_Cmd, READ_DIRECTION+DMA_IDLE_CMD); /* | DMA_INT */
	    dc390_laststatus &= ~0xff000000; dc390_laststatus |= bval << 24;

	    DEBUG1(printk (KERN_DEBUG "Blast: Read %i times DMA_Status %02x", 0xa000-i, bval);)
	    ResidCnt = (UINT) DC390_read8 (CtcReg_High);
	    ResidCnt <<= 8;
	    ResidCnt |= (UINT) DC390_read8 (CtcReg_Mid);
	    ResidCnt <<= 8;
	    ResidCnt |= (UINT) DC390_read8 (CtcReg_Low);

	    xferCnt = pSRB->SGToBeXferLen - ResidCnt;
	    pSRB->SGBusAddr += xferCnt;
	    pSRB->TotalXferredLen += xferCnt;
	    pSRB->SGToBeXferLen = ResidCnt;

	    if( residual )
	    {
		bval = DC390_read8 (ScsiFifo);	    /* get one residual byte */
		ptr = (PUCHAR) bus_to_virt( pSRB->SGBusAddr );
		*ptr = bval;
		pSRB->SGBusAddr++; xferCnt++;
		pSRB->TotalXferredLen++;
		pSRB->SGToBeXferLen--;
	    }
	    DEBUG1(printk (KERN_DEBUG "Xfered: %li, Total: %li, Remaining: %li\n", xferCnt,\
			   pSRB->TotalXferredLen, pSRB->SGToBeXferLen);)

	}
    }
    if ((*psstatus & 7) != SCSI_DATA_IN)
    {
	    DC390_write8 (ScsiCmd, CLEAR_FIFO_CMD);
	    DC390_write8 (DMA_Cmd, READ_DIRECTION+DMA_IDLE_CMD); /* | DMA_INT */
    }	    
}

static void
dc390_Command_0( PACB pACB, PSRB pSRB, PUCHAR psstatus)
{
}

static void
dc390_Status_0( PACB pACB, PSRB pSRB, PUCHAR psstatus)
{

    pSRB->TargetStatus = DC390_read8 (ScsiFifo);
    //udelay (1);
    pSRB->EndMessage = DC390_read8 (ScsiFifo);	/* get message */

    *psstatus = SCSI_NOP0;
    pSRB->SRBState = SRB_COMPLETED;
    DC390_write8 (ScsiCmd, MSG_ACCEPTED_CMD);
}

static void
dc390_MsgOut_0( PACB pACB, PSRB pSRB, PUCHAR psstatus)
{
    if( pSRB->SRBState & (SRB_UNEXPECT_RESEL+SRB_ABORT_SENT) )
	*psstatus = SCSI_NOP0;
    //DC390_write8 (DMA_Cmd, DMA_IDLE_CMD);
}


static void __inline__
dc390_reprog (PACB pACB, PDCB pDCB)
{
  DC390_write8 (Sync_Period, pDCB->SyncPeriod);
  DC390_write8 (Sync_Offset, pDCB->SyncOffset);
  DC390_write8 (CtrlReg3, pDCB->CtrlR3);
  DC390_write8 (CtrlReg4, pDCB->CtrlR4);
  dc390_SetXferRate (pACB, pDCB);
};


#ifdef DC390_DEBUG0
static void
dc390_printMsg (UCHAR *MsgBuf, UCHAR len)
{
  int i;
  printk (" %02x", MsgBuf[0]);
  for (i = 1; i < len; i++)
    printk (" %02x", MsgBuf[i]);
  printk ("\n");
};
#endif

#define DC390_ENABLE_MSGOUT DC390_write8 (ScsiCmd, SET_ATN_CMD)

/* reject_msg */
static void __inline__
dc390_MsgIn_reject (PACB pACB, PSRB pSRB)
{
  pSRB->MsgOutBuf[0] = MESSAGE_REJECT;
  pSRB->MsgCnt = 1; DC390_ENABLE_MSGOUT;
  DEBUG0 (printk (KERN_INFO "DC390: Reject message\n");)
}

/* abort command */
static void __inline__
dc390_EnableMsgOut_Abort ( PACB pACB, PSRB pSRB )
{
    pSRB->MsgOutBuf[0] = ABORT; 
    pSRB->MsgCnt = 1; DC390_ENABLE_MSGOUT;
    pSRB->pSRBDCB->DCBFlag &= ~ABORT_DEV_;
}

static PSRB
dc390_MsgIn_QTag (PACB pACB, PDCB pDCB, UCHAR tag)
{
  PSRB lastSRB = pDCB->pGoingLast;
  PSRB pSRB = pDCB->pGoingSRB;

  if (pSRB)
    {
      for( ;pSRB ; )
	{
	  if (pSRB->TagNumber == tag) break;
	  if (pSRB == lastSRB) goto mingx0;
	  pSRB = pSRB->pNextSRB;
	}

      if( pDCB->DCBFlag & ABORT_DEV_ )
	{
	  pSRB->SRBState = SRB_ABORT_SENT;
	  dc390_EnableMsgOut_Abort( pACB, pSRB );
	}

      if( !(pSRB->SRBState & SRB_DISCONNECT) )
	goto  mingx0;

      pDCB->pActiveSRB = pSRB;
      pSRB->SRBState = SRB_DATA_XFER;
    }
  else
    {
    mingx0:
      pSRB = pACB->pTmpSRB;
      pSRB->SRBState = SRB_UNEXPECT_RESEL;
      pDCB->pActiveSRB = pSRB;
      pSRB->MsgOutBuf[0] = ABORT_TAG;
      pSRB->MsgCnt = 1; DC390_ENABLE_MSGOUT;
    }
  return pSRB;
}


/* set async transfer mode */
static void 
dc390_MsgIn_set_async (PACB pACB, PSRB pSRB)
{
  PDCB pDCB = pSRB->pSRBDCB;
  if (!(pSRB->SRBState & DO_SYNC_NEGO)) 
    printk (KERN_INFO "DC390: Target %i initiates Non-Sync?\n", pDCB->TargetID);
  pSRB->SRBState &= ~DO_SYNC_NEGO;
  pDCB->SyncMode &= ~(SYNC_ENABLE+SYNC_NEGO_DONE);
  pDCB->SyncPeriod = 0;
  pDCB->SyncOffset = 0;
  //pDCB->NegoPeriod = 50; /* 200ns <=> 5 MHz */
  pDCB->CtrlR3 = FAST_CLK;	/* fast clock / normal scsi */
  pDCB->CtrlR4 &= 0x3f;
  pDCB->CtrlR4 |= pACB->glitch_cfg;	/* glitch eater */
  dc390_reprog (pACB, pDCB);
}

/* set sync transfer mode */
static void
dc390_MsgIn_set_sync (PACB pACB, PSRB pSRB)
{
  UCHAR bval;
  USHORT wval, wval1;
  PDCB pDCB = pSRB->pSRBDCB;
  UCHAR oldsyncperiod = pDCB->SyncPeriod;
  UCHAR oldsyncoffset = pDCB->SyncOffset;
  
  if (!(pSRB->SRBState & DO_SYNC_NEGO))
    {
      printk (KERN_INFO "DC390: Target %i initiates Sync: %ins %i ... answer ...\n", 
	      pDCB->TargetID, pSRB->MsgInBuf[3]<<2, pSRB->MsgInBuf[4]);

      /* reject */
      //dc390_MsgIn_reject (pACB, pSRB);
      //return dc390_MsgIn_set_async (pACB, pSRB);

      /* Reply with corrected SDTR Message */
      if (pSRB->MsgInBuf[4] > 15)
	{ 
	  printk (KERN_INFO "DC390: Lower Sync Offset to 15\n");
	  pSRB->MsgInBuf[4] = 15;
	}
      if (pSRB->MsgInBuf[3] < pDCB->NegoPeriod)
	{
	  printk (KERN_INFO "DC390: Set sync nego period to %ins\n", pDCB->NegoPeriod << 2);
	  pSRB->MsgInBuf[3] = pDCB->NegoPeriod;
	};
      memcpy (pSRB->MsgOutBuf, pSRB->MsgInBuf, 5);
      pSRB->MsgCnt = 5;
      DC390_ENABLE_MSGOUT;
    };

  pSRB->SRBState &= ~DO_SYNC_NEGO;
  pDCB->SyncMode |= SYNC_ENABLE+SYNC_NEGO_DONE;
  pDCB->SyncOffset &= 0x0f0;
  pDCB->SyncOffset |= pSRB->MsgInBuf[4];
  pDCB->NegoPeriod = pSRB->MsgInBuf[3];

  wval = (USHORT) pSRB->MsgInBuf[3];
  wval = wval << 2; wval -= 3; wval1 = wval / 25;	/* compute speed */
  if( (wval1 * 25) != wval) wval1++;
  bval = FAST_CLK+FAST_SCSI;	/* fast clock / fast scsi */

  pDCB->CtrlR4 &= 0x3f;		/* Glitch eater: 12ns less than normal */
  if (pACB->glitch_cfg != NS_TO_GLITCH(0))
    pDCB->CtrlR4 |= NS_TO_GLITCH(((GLITCH_TO_NS(pACB->glitch_cfg)) - 1));
  else
    pDCB->CtrlR4 |= NS_TO_GLITCH(0);
  if (wval1 < 4) pDCB->CtrlR4 |= NS_TO_GLITCH(0); /* Ultra */

  if (wval1 >= 8)
    {
      wval1--;	/* Timing computation differs by 1 from FAST_SCSI */
      bval = FAST_CLK;		/* fast clock / normal scsi */
      pDCB->CtrlR4 |= pACB->glitch_cfg; 	/* glitch eater */
    }

  pDCB->CtrlR3 = bval;
  pDCB->SyncPeriod = (UCHAR)wval1;
  
  if ((oldsyncperiod != wval1 || oldsyncoffset != pDCB->SyncOffset) && pDCB->TargetLUN == 0)
    {
      if (! (bval & FAST_SCSI)) wval1++;
      printk (KERN_INFO "DC390: Target %i: Sync transfer %i.%1i MHz, Offset %i\n", pDCB->TargetID, 
	      40/wval1, ((40%wval1)*10+wval1/2)/wval1, pDCB->SyncOffset & 0x0f);
    }
  
  dc390_reprog (pACB, pDCB);
};


/* handle RESTORE_PTR */
static void 
dc390_restore_ptr (PACB pACB, PSRB pSRB)
{
  PSGL psgl;
  pSRB->TotalXferredLen = 0;
  pSRB->SGIndex = 0;
  if( pSRB->pcmd->use_sg )
    {
      pSRB->SGcount = (UCHAR) pSRB->pcmd->use_sg;
      pSRB->pSegmentList = (PSGL) pSRB->pcmd->request_buffer;
      psgl = pSRB->pSegmentList;
      while (pSRB->TotalXferredLen + (ULONG) psgl->length < pSRB->Saved_Ptr)
	{
	  pSRB->TotalXferredLen += (ULONG) psgl->length;
	  pSRB->SGIndex++;
	  if( pSRB->SGIndex < pSRB->SGcount )
	    {
	      pSRB->pSegmentList++;
	      psgl = pSRB->pSegmentList;
	      
	      pSRB->SGBusAddr = virt_to_bus( psgl->address );
	      pSRB->SGToBeXferLen = (ULONG) psgl->length;
	    }
	  else
	    pSRB->SGToBeXferLen = 0;
	}
      pSRB->SGToBeXferLen -= (pSRB->Saved_Ptr - pSRB->TotalXferredLen);
      pSRB->SGBusAddr += (pSRB->Saved_Ptr - pSRB->TotalXferredLen);
      printk (KERN_INFO "DC390: Pointer restored. Segment %i, Total %li, Bus %08lx\n", pSRB->SGIndex, pSRB->Saved_Ptr, pSRB->SGBusAddr);
    }
    else if( pSRB->pcmd->request_buffer )
    {
	pSRB->SGcount = 1;
	pSRB->pSegmentList = (PSGL) &pSRB->Segmentx;
	pSRB->Segmentx.address = (PUCHAR) pSRB->pcmd->request_buffer + pSRB->Saved_Ptr;
	pSRB->Segmentx.length = pSRB->pcmd->request_bufflen - pSRB->Saved_Ptr;
	printk (KERN_INFO "DC390: Pointer restored. Total %li, Bus %p\n",
		pSRB->Saved_Ptr, pSRB->Segmentx.address);
    }
     else
       {
	 pSRB->SGcount = 0;
	 printk (KERN_INFO "DC390: RESTORE_PTR message for Transfer without Scatter-Gather ??\n");
       };

  pSRB->TotalXferredLen = pSRB->Saved_Ptr;
};


/* According to the docs, the AM53C974 reads the message and 
 * generates a Succesful Operation IRQ before asserting ACK for
 * the last byte (how does it know whether it's the last ?) */
/* The old code handled it in another way, indicating, that on
 * every message byte an IRQ is generated and every byte has to
 * be manually ACKed. Hmmm ?  (KG, 98/11/28) */
/* The old implementation was correct. Sigh! */

/* Check if the message is complete */
static UCHAR __inline__
dc390_MsgIn_complete (UCHAR *msgbuf, UINT len)
{ 
  if (*msgbuf == EXTENDED_MESSAGE)
  {
	if (len < 2) return 0;
	if (len < msgbuf[1] + 2) return 0;
  }
  else if (*msgbuf >= 0x20 && *msgbuf <= 0x2f) // two byte messages
	if (len < 2) return 0;
  return 1;
}



/* read and eval received messages */
void
dc390_MsgIn_0( PACB pACB, PSRB pSRB, PUCHAR psstatus)
{
    PDCB   pDCB = pACB->pActiveDCB;

    /* Read the msg */

    pSRB->MsgInBuf[pACB->MsgLen++] = DC390_read8 (ScsiFifo);
    //pSRB->SRBState = 0;

    /* Msg complete ? */
    if (dc390_MsgIn_complete (pSRB->MsgInBuf, pACB->MsgLen))
      {
	DEBUG0 (printk (KERN_INFO "DC390: MsgIn:"); dc390_printMsg (pSRB->MsgInBuf, pACB->MsgLen);)
	/* Now eval the msg */
	switch (pSRB->MsgInBuf[0]) 
	  {
	  case DISCONNECT: 
	    pSRB->SRBState = SRB_DISCONNECT; break;
	    
	  case SIMPLE_QUEUE_TAG:
	  case HEAD_OF_QUEUE_TAG:
	  case ORDERED_QUEUE_TAG:
	    pSRB = dc390_MsgIn_QTag (pACB, pDCB, pSRB->MsgInBuf[1]);
	    break;
	    
	  case MESSAGE_REJECT: 
	    DC390_write8 (ScsiCmd, RESET_ATN_CMD);
	    pDCB->NegoPeriod = 50; /* 200ns <=> 5 MHz */
	    if( pSRB->SRBState & DO_SYNC_NEGO)
	      dc390_MsgIn_set_async (pACB, pSRB);
	    break;
	    
	  case EXTENDED_MESSAGE:
	    /* reject every extended msg but SDTR */
	    if (pSRB->MsgInBuf[1] != 3 || pSRB->MsgInBuf[2] != EXTENDED_SDTR)
	      dc390_MsgIn_reject (pACB, pSRB);
	    else
	      {
		if (pSRB->MsgInBuf[3] == 0 || pSRB->MsgInBuf[4] == 0)
		  dc390_MsgIn_set_async (pACB, pSRB);
		else
		  dc390_MsgIn_set_sync (pACB, pSRB);
	      };
	    
	    // nothing has to be done
	  case COMMAND_COMPLETE: break;
	    
	    // SAVE POINTER may be ignored as we have the PSRB associated with the
	    // scsi command. Thanks, Gerard, for pointing it out.
	  case SAVE_POINTERS: 
	    pSRB->Saved_Ptr = pSRB->TotalXferredLen;
	    break;
	    // The device might want to restart transfer with a RESTORE
	  case RESTORE_POINTERS:
	    DEBUG0(printk ("DC390: RESTORE POINTER message received ... try to handle\n");)
	    dc390_restore_ptr (pACB, pSRB);
	    break;

	    // reject unknown messages
	  default: dc390_MsgIn_reject (pACB, pSRB);
	  }
	
	/* Clear counter and MsgIn state */
	pSRB->SRBState &= ~SRB_MSGIN;
	pACB->MsgLen = 0;
      };

    *psstatus = SCSI_NOP0;
    DC390_write8 (ScsiCmd, MSG_ACCEPTED_CMD);
    //DC390_write8 (DMA_Cmd, DMA_IDLE_CMD);
}


void
dc390_DataIO_Comm( PACB pACB, PSRB pSRB, UCHAR ioDir)
{
    PSGL   psgl;
    ULONG  lval;
    PDCB   pDCB = pACB->pActiveDCB;

    if (pSRB == pACB->pTmpSRB)
    {
	if (pDCB) printk (KERN_ERR "DC390: pSRB == pTmpSRB! (TagQ Error?) (%02i-%i)\n",
			  pDCB->TargetID, pDCB->TargetLUN);
	else printk (KERN_ERR "DC390: pSRB == pTmpSRB! (TagQ Error?) (DCB 0!)\n");
	dc390_EnableMsgOut_Abort (pACB, pSRB);
	if (pDCB) pDCB->DCBFlag |= ABORT_DEV;
	return;
    }

    if( pSRB->SGIndex < pSRB->SGcount )
    {
	DC390_write8 (DMA_Cmd, DMA_IDLE_CMD | ioDir /* | DMA_INT */);
	if( !pSRB->SGToBeXferLen )
	{
	    psgl = pSRB->pSegmentList;
	    pSRB->SGBusAddr = virt_to_bus( psgl->address );