tmscsim.c

Linux内核源代码 为压缩文件 是<<Linux内核>>一书中的源代码

/* Append to Query List */
static void dc390_Query_append( PSCSICMD cmd, PACB pACB )
{
    DEBUG0(printk ("DC390: Append cmd %li to Query\n", cmd->pid);)
    if( !pACB->QueryCnt )
	pACB->pQueryHead = cmd;
    else
	pACB->pQueryTail->next = cmd;

    pACB->pQueryTail = cmd;
    pACB->QueryCnt++;
    pACB->CmdOutOfSRB++;
    cmd->next = NULL;
}


/* Return next cmd from Query list */
static PSCSICMD dc390_Query_get ( PACB pACB )
{
    PSCSICMD  pcmd;

    pcmd = pACB->pQueryHead;
    if (!pcmd) return pcmd;
    DEBUG0(printk ("DC390: Get cmd %li from Query\n", pcmd->pid);)
    pACB->pQueryHead = pcmd->next;
    pcmd->next = NULL;
    if (!pACB->pQueryHead) pACB->pQueryTail = NULL;
    pACB->QueryCnt--;
    return( pcmd );
}


/* Return next free SRB */
static __inline__ PSRB dc390_Free_get ( PACB pACB )
{
    PSRB   pSRB;

    pSRB = pACB->pFreeSRB;
    DEBUG0(printk ("DC390: Get Free SRB %p\n", pSRB);)
    if( pSRB )
    {
	pACB->pFreeSRB = pSRB->pNextSRB;
	pSRB->pNextSRB = NULL;
    }

    return( pSRB );
}

/* Insert SRB oin top of free list */
static __inline__ void dc390_Free_insert (PACB pACB, PSRB pSRB)
{
    DEBUG0(printk ("DC390: Free SRB %p\n", pSRB);)
    pSRB->pNextSRB = pACB->pFreeSRB;
    pACB->pFreeSRB = pSRB;
}


/* Inserts a SRB to the top of the Waiting list */
static __inline__ void dc390_Waiting_insert ( PDCB pDCB, PSRB pSRB )
{
    DEBUG0(printk ("DC390: Insert pSRB %p cmd %li to Waiting\n", pSRB, pSRB->pcmd->pid);)
    pSRB->pNextSRB = pDCB->pWaitingSRB;
    if (!pDCB->pWaitingSRB)
	pDCB->pWaitLast = pSRB;
    pDCB->pWaitingSRB = pSRB;
    pDCB->WaitSRBCnt++;
}


/* Queue SRB to waiting list */
static __inline__ void dc390_Waiting_append ( PDCB pDCB, PSRB pSRB)
{
    DEBUG0(printk ("DC390: Append pSRB %p cmd %li to Waiting\n", pSRB, pSRB->pcmd->pid);)
    if( pDCB->pWaitingSRB )
	pDCB->pWaitLast->pNextSRB = pSRB;
    else
	pDCB->pWaitingSRB = pSRB;

    pDCB->pWaitLast = pSRB;
    pSRB->pNextSRB = NULL;
    pDCB->WaitSRBCnt++;
    pDCB->pDCBACB->CmdInQ++;
}

static __inline__ void dc390_Going_append (PDCB pDCB, PSRB pSRB)
{
    pDCB->GoingSRBCnt++;
    DEBUG0(printk("DC390: Append SRB %p to Going\n", pSRB);)
    /* Append to the list of Going commands */
    if( pDCB->pGoingSRB )
	pDCB->pGoingLast->pNextSRB = pSRB;
    else
	pDCB->pGoingSRB = pSRB;

    pDCB->pGoingLast = pSRB;
    /* No next one in sent list */
    pSRB->pNextSRB = NULL;
};

static __inline__ void dc390_Going_remove (PDCB pDCB, PSRB pSRB)
{
   DEBUG0(printk("DC390: Remove SRB %p from Going\n", pSRB);)
   if (pSRB == pDCB->pGoingSRB)
	pDCB->pGoingSRB = pSRB->pNextSRB;
   else
     {
	PSRB psrb = pDCB->pGoingSRB;
	while (psrb && psrb->pNextSRB != pSRB)
	  psrb = psrb->pNextSRB;
	if (!psrb) 
	  { printk (KERN_ERR "DC390: Remove non-ex. SRB %p from Going!\n", pSRB); return; }
	psrb->pNextSRB = pSRB->pNextSRB;
	if (pSRB == pDCB->pGoingLast)
	  pDCB->pGoingLast = psrb;
     }
   pDCB->GoingSRBCnt--;
};

/* Moves SRB from Going list to the top of Waiting list */
static void dc390_Going_to_Waiting ( PDCB pDCB, PSRB pSRB )
{
    DEBUG0(printk(KERN_INFO "DC390: Going_to_Waiting (SRB %p) pid = %li\n", pSRB, pSRB->pcmd->pid);)
    /* Remove SRB from Going */
    dc390_Going_remove (pDCB, pSRB);
    /* Insert on top of Waiting */
    dc390_Waiting_insert (pDCB, pSRB);
    /* Tag Mask must be freed elsewhere ! (KG, 99/06/18) */
}

/* Moves first SRB from Waiting list to Going list */
static __inline__ void dc390_Waiting_to_Going ( PDCB pDCB, PSRB pSRB )
{	
	/* Remove from waiting list */
	DEBUG0(printk("DC390: Remove SRB %p from head of Waiting\n", pSRB);)
	pDCB->pWaitingSRB = pSRB->pNextSRB;
	if( !pDCB->pWaitingSRB ) pDCB->pWaitLast = NULL;
	pDCB->WaitSRBCnt--;
	dc390_Going_append (pDCB, pSRB);
}

/* 2.0 timer compatibility */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,1,30)
 static inline int timer_pending(struct timer_list * timer)
 {
	return timer->prev != NULL;
 }
 #define time_after(a,b)         ((long)(b) - (long)(a) < 0)
 #define time_before(a,b)        time_after(b,a)
#endif

void DC390_waiting_timed_out (unsigned long ptr);
/* Sets the timer to wake us up */
static void dc390_waiting_timer (PACB pACB, unsigned long to)
{
	if (timer_pending (&pACB->Waiting_Timer)) return;
	init_timer (&pACB->Waiting_Timer);
	pACB->Waiting_Timer.function = DC390_waiting_timed_out;
	pACB->Waiting_Timer.data = (unsigned long)pACB;
	if (time_before (jiffies + to, pACB->pScsiHost->last_reset))
		pACB->Waiting_Timer.expires = pACB->pScsiHost->last_reset + 1;
	else
		pACB->Waiting_Timer.expires = jiffies + to + 1;
	add_timer (&pACB->Waiting_Timer);
}


/* Send the next command from the waiting list to the bus */
static void dc390_Waiting_process ( PACB pACB )
{
    PDCB   ptr, ptr1;
    PSRB   pSRB;

    if( (pACB->pActiveDCB) || (pACB->ACBFlag & (RESET_DETECT+RESET_DONE+RESET_DEV) ) )
	return;
    if (timer_pending (&pACB->Waiting_Timer)) del_timer (&pACB->Waiting_Timer);
    ptr = pACB->pDCBRunRobin;
    if( !ptr )
      {
	ptr = pACB->pLinkDCB;
	pACB->pDCBRunRobin = ptr;
      }
    ptr1 = ptr;
    if (!ptr1) return;
    do 
      {
	pACB->pDCBRunRobin = ptr1->pNextDCB;
	if( !( pSRB = ptr1->pWaitingSRB ) ||
	    ( ptr1->MaxCommand <= ptr1->GoingSRBCnt ))
	  ptr1 = ptr1->pNextDCB;
	else
	  {
	    /* Try to send to the bus */
	    if( !dc390_StartSCSI(pACB, ptr1, pSRB) )
	      dc390_Waiting_to_Going (ptr1, pSRB);
	    else
	      dc390_waiting_timer (pACB, HZ/5);
	    break;
	  }
      } while (ptr1 != ptr);
    return;
}

/* Wake up waiting queue */
void DC390_waiting_timed_out (unsigned long ptr)
{
	PACB pACB = (PACB)ptr;
	DC390_IFLAGS
	DC390_AFLAGS
	DEBUG0(printk ("DC390: Debug: Waiting queue woken up by timer!\n");)
	DC390_LOCK_IO;
	DC390_LOCK_ACB;
	dc390_Waiting_process (pACB);
	DC390_UNLOCK_ACB;
	DC390_UNLOCK_IO;
}

/***********************************************************************
 * Function: static void dc390_SendSRB (PACB pACB, PSRB pSRB)
 *
 * Purpose: Send SCSI Request Block (pSRB) to adapter (pACB)
 *
 ***********************************************************************/

static void dc390_SendSRB( PACB pACB, PSRB pSRB )
{
    PDCB   pDCB;

    pDCB = pSRB->pSRBDCB;
    if( (pDCB->MaxCommand <= pDCB->GoingSRBCnt) || (pACB->pActiveDCB) ||
	(pACB->ACBFlag & (RESET_DETECT+RESET_DONE+RESET_DEV)) )
    {
	dc390_Waiting_append (pDCB, pSRB);
	dc390_Waiting_process (pACB);
	return;
    }

#if 0
    if( pDCB->pWaitingSRB )
    {
	dc390_Waiting_append (pDCB, pSRB);
/*	pSRB = GetWaitingSRB(pDCB); */	/* non-existent */
	pSRB = pDCB->pWaitingSRB;
	/* Remove from waiting list */
	pDCB->pWaitingSRB = pSRB->pNextSRB;
	pSRB->pNextSRB = NULL;
	if (!pDCB->pWaitingSRB) pDCB->pWaitLast = NULL;
    }
#endif
	
    if (!dc390_StartSCSI(pACB, pDCB, pSRB))
	dc390_Going_append (pDCB, pSRB);
    else {
	dc390_Waiting_insert (pDCB, pSRB);
	dc390_waiting_timer (pACB, HZ/5);
    };
}

/***********************************************************************
 * Function: static void dc390_BuildSRB (Scsi_Cmd *pcmd, PDCB pDCB, 
 * 					 PSRB pSRB)
 *
 * Purpose: Prepare SRB for being sent to Device DCB w/ command *pcmd
 *
 ***********************************************************************/

static void dc390_BuildSRB (Scsi_Cmnd* pcmd, PDCB pDCB, PSRB pSRB)
{
    pSRB->pSRBDCB = pDCB;
    pSRB->pcmd = pcmd;
    //pSRB->ScsiCmdLen = pcmd->cmd_len;
    //memcpy (pSRB->CmdBlock, pcmd->cmnd, pcmd->cmd_len);
    
    if( pcmd->use_sg )
    {
	pSRB->SGcount = (UCHAR) pcmd->use_sg;
	pSRB->pSegmentList = (PSGL) pcmd->request_buffer;
    }
    else if( pcmd->request_buffer )
    {
	pSRB->SGcount = 1;
	pSRB->pSegmentList = (PSGL) &pSRB->Segmentx;
	pSRB->Segmentx.address = (PUCHAR) pcmd->request_buffer;
	pSRB->Segmentx.length = pcmd->request_bufflen;
    }
    else
	pSRB->SGcount = 0;

    pSRB->SGIndex = 0;
    pSRB->AdaptStatus = 0;
    pSRB->TargetStatus = 0;
    pSRB->MsgCnt = 0;
    if( pDCB->DevType != TYPE_TAPE )
	pSRB->RetryCnt = 1;
    else
	pSRB->RetryCnt = 0;
    pSRB->SRBStatus = 0;
    pSRB->SRBFlag = 0;
    pSRB->SRBState = 0;
    pSRB->TotalXferredLen = 0;
    pSRB->SGBusAddr = 0;
    pSRB->SGToBeXferLen = 0;
    pSRB->ScsiPhase = 0;
    pSRB->EndMessage = 0;
    pSRB->TagNumber = 255;
};

/* Put cmnd from Query to Waiting list and send next Waiting cmnd */
static void dc390_Query_to_Waiting (PACB pACB)
{
    Scsi_Cmnd *pcmd;
    PSRB   pSRB;
    PDCB   pDCB;

    if( pACB->ACBFlag & (RESET_DETECT+RESET_DONE+RESET_DEV) )
	return;

    while (pACB->QueryCnt)
    {
	pSRB = dc390_Free_get ( pACB );
	if (!pSRB) return;
	pcmd = dc390_Query_get ( pACB );
	if (!pcmd) { dc390_Free_insert (pACB, pSRB); return; }; /* should not happen */
	pDCB = dc390_findDCB (pACB, pcmd->target, pcmd->lun);
	if (!pDCB) 
	{ 
		dc390_Free_insert (pACB, pSRB);
		printk (KERN_ERR "DC390: Command in queue to non-existing device!\n");
		pcmd->result = MK_RES(DRIVER_ERROR,DID_ERROR,0,0);
		DC390_UNLOCK_ACB_NI;
		pcmd->done (pcmd);
		DC390_LOCK_ACB_NI;
	};
	dc390_BuildSRB (pcmd, pDCB, pSRB);
	dc390_Waiting_append ( pDCB, pSRB );
    }
}

/***********************************************************************
 * Function : static int DC390_queue_command (Scsi_Cmnd *cmd,
 *					       void (*done)(Scsi_Cmnd *))
 *
 * Purpose : enqueues a SCSI command
 *
 * Inputs : cmd - SCSI command, done - callback function called on 
 *	    completion, with a pointer to the command descriptor.
 *
 * Returns : (depending on kernel version)
 * 2.0.x: always return 0
 * 2.1.x: old model: (use_new_eh_code == 0): like 2.0.x
 *	  TO BE DONE:
 *	  new model: return 0 if successful
 *	  	     return 1 if command cannot be queued (queue full)
 *		     command will be inserted in midlevel queue then ...
 *
 ***********************************************************************/

int DC390_queue_command (Scsi_Cmnd *cmd, void (* done)(Scsi_Cmnd *))
{
    PDCB   pDCB;
    PSRB   pSRB;
    DC390_AFLAGS
    PACB   pACB = (PACB) cmd->host->hostdata;


    DEBUG0(/*  if(pACB->scan_devices) */	\
	printk(KERN_INFO "DC390: Queue Cmd=%02x,Tgt=%d,LUN=%d (pid=%li)\n",\
		cmd->cmnd[0],cmd->target,cmd->lun,cmd->pid);)

    DC390_LOCK_ACB;
    
    /* Assume BAD_TARGET; will be cleared later */
    cmd->result = DID_BAD_TARGET << 16;
   
    /* TODO: Change the policy: Alway accept TEST_UNIT_READY or INQUIRY 
     * commands and alloc a DCB for the device if not yet there. DCB will
     * be removed in dc390_SRBdone if SEL_TIMEOUT */

    if( (pACB->scan_devices == END_SCAN) && (cmd->cmnd[0] != INQUIRY) )
	pACB->scan_devices = 0;

    else if( (pACB->scan_devices) && (cmd->cmnd[0] == READ_6) )
	pACB->scan_devices = 0;

    if ( ( cmd->target >= pACB->pScsiHost->max_id ) || 
	 (cmd->lun >= pACB->pScsiHost->max_lun) )
    {
/*	printk ("DC390: Ignore target %d lun %d\n",
		cmd->target, cmd->lun); */
	DC390_UNLOCK_ACB;
	//return (1);
	done (cmd);
	return (0);
    }

    if( (pACB->scan_devices || cmd->cmnd[0] == TEST_UNIT_READY || cmd->cmnd[0] == INQUIRY) && 
       !(pACB->DCBmap[cmd->target] & (1 << cmd->lun)) )
    {
        pACB->scan_devices = 1;

	dc390_initDCB( pACB, &pDCB, cmd->target, cmd->lun );
	if (!pDCB)
	  {
	    printk (KERN_ERR "DC390: kmalloc for DCB failed, target %02x lun %02x\n", 
		    cmd->target, cmd->lun);
	    DC390_UNLOCK_ACB;
	    printk ("DC390: No DCB in queue_command!\n");
#ifdef USE_NEW_EH
	    return (1);
#else
	    done (cmd);
	    return (0);
#endif
	  };
            
    }
    else if( !(pACB->scan_devices) && !(pACB->DCBmap[cmd->target] & (1 << cmd->lun)) )
    {
	printk(KERN_INFO "DC390: Ignore target %02x lun %02x\n",
		cmd->target, cmd->lun); 
	DC390_UNLOCK_ACB;
	//return (1);
	done (cmd);
	return (0);
    }
    else
    {
	pDCB = dc390_findDCB (pACB, cmd->target, cmd->lun);
	if (!pDCB)
	 {  /* should never happen */