atari_NCR5380.c

    while (1) {
	tmp = NCR5380_read(STATUS_REG);
	/* We only have a valid SCSI phase when REQ is asserted */
	if (tmp & SR_REQ) {
	    phase = (tmp & PHASE_MASK); 
	    if (phase != old_phase) {
		old_phase = phase;
		NCR_PRINT_PHASE(NDEBUG_INFORMATION);
	    }
	    
	    if (sink && (phase != PHASE_MSGOUT)) {
		NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | 
		    ICR_ASSERT_ACK);
		while (NCR5380_read(STATUS_REG) & SR_REQ);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
		    ICR_ASSERT_ATN);
		sink = 0;
		continue;
	    }

	    switch (phase) {
	    case PHASE_DATAOUT:
#if (NDEBUG & NDEBUG_NO_DATAOUT)
		printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
		       "aborted\n", HOSTNO);
		sink = 1;
		do_abort(instance);
		cmd->result = DID_ERROR  << 16;
		cmd->done(cmd);
		return;
#endif
	    case PHASE_DATAIN:
		/* 
		 * If there is no room left in the current buffer in the
		 * scatter-gather list, move onto the next one.
		 */

		if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
		    ++cmd->SCp.buffer;
		    --cmd->SCp.buffers_residual;
		    cmd->SCp.this_residual = cmd->SCp.buffer->length;
		    cmd->SCp.ptr = page_address(cmd->SCp.buffer->page)+
				   cmd->SCp.buffer->offset;
		    /* ++roman: Try to merge some scatter-buffers if
		     * they are at contiguous physical addresses.
		     */
		    merge_contiguous_buffers( cmd );
		    INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
			       HOSTNO, cmd->SCp.this_residual,
			       cmd->SCp.buffers_residual);
		}

		/*
		 * The preferred transfer method is going to be 
		 * PSEUDO-DMA for systems that are strictly PIO,
		 * since we can let the hardware do the handshaking.
		 *
		 * For this to work, we need to know the transfersize
		 * ahead of time, since the pseudo-DMA code will sit
		 * in an unconditional loop.
		 */

/* ++roman: I suggest, this should be
 *   #if def(REAL_DMA)
 * instead of leaving REAL_DMA out.
 */

#if defined(REAL_DMA)
		if (!cmd->device->borken &&
		    (transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
		    len = transfersize;
		    cmd->SCp.phase = phase;
		    if (NCR5380_transfer_dma(instance, &phase,
			&len, (unsigned char **) &cmd->SCp.ptr)) {
			/*
			 * If the watchdog timer fires, all future
			 * accesses to this device will use the
			 * polled-IO. */ 
			printk(KERN_NOTICE "scsi%d: switching target %d "
			       "lun %d to slow handshake\n", HOSTNO,
			       cmd->device->id, cmd->device->lun);
			cmd->device->borken = 1;
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
			    ICR_ASSERT_ATN);
			sink = 1;
			do_abort(instance);
			cmd->result = DID_ERROR  << 16;
			cmd->done(cmd);
			/* XXX - need to source or sink data here, as appropriate */
		    } else {
#ifdef REAL_DMA
			/* ++roman: When using real DMA,
			 * information_transfer() should return after
			 * starting DMA since it has nothing more to
			 * do.
			 */
			return;
#else			
			cmd->SCp.this_residual -= transfersize - len;
#endif
		    }
		} else
#endif /* defined(REAL_DMA) */
		  NCR5380_transfer_pio(instance, &phase, 
		    (int *) &cmd->SCp.this_residual, (unsigned char **)
		    &cmd->SCp.ptr);
		break;
	    case PHASE_MSGIN:
		len = 1;
		data = &tmp;
		NCR5380_write(SELECT_ENABLE_REG, 0); 	/* disable reselects */
		NCR5380_transfer_pio(instance, &phase, &len, &data);
		cmd->SCp.Message = tmp;

		switch (tmp) {
		/*
		 * Linking lets us reduce the time required to get the 
		 * next command out to the device, hopefully this will
		 * mean we don't waste another revolution due to the delays
		 * required by ARBITRATION and another SELECTION.
		 *
		 * In the current implementation proposal, low level drivers
		 * merely have to start the next command, pointed to by 
		 * next_link, done() is called as with unlinked commands.
		 */
#ifdef LINKED
		case LINKED_CMD_COMPLETE:
		case LINKED_FLG_CMD_COMPLETE:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    
		    LNK_PRINTK("scsi%d: target %d lun %d linked command "
			       "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);

		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    /*
		     * Sanity check : A linked command should only terminate
		     * with one of these messages if there are more linked
		     * commands available.
		     */

		    if (!cmd->next_link) {
			 printk(KERN_NOTICE "scsi%d: target %d lun %d "
				"linked command complete, no next_link\n",
				HOSTNO, cmd->device->id, cmd->device->lun);
			    sink = 1;
			    do_abort (instance);
			    return;
		    }

		    initialize_SCp(cmd->next_link);
		    /* The next command is still part of this process; copy it
		     * and don't free it! */
		    cmd->next_link->tag = cmd->tag;
		    cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); 
		    LNK_PRINTK("scsi%d: target %d lun %d linked request "
			       "done, calling scsi_done().\n",
			       HOSTNO, cmd->device->id, cmd->device->lun);
#ifdef NCR5380_STATS
		    collect_stats(hostdata, cmd);
#endif
		    cmd->scsi_done(cmd);
		    cmd = hostdata->connected;
		    break;
#endif /* def LINKED */
		case ABORT:
		case COMMAND_COMPLETE: 
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    /* ++guenther: possible race with Falcon locking */
		    falcon_dont_release++;
		    hostdata->connected = NULL;
		    QU_PRINTK("scsi%d: command for target %d, lun %d "
			      "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
#ifdef SUPPORT_TAGS
		    cmd_free_tag( cmd );
		    if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
			/* Turn a QUEUE FULL status into BUSY, I think the
			 * mid level cannot handle QUEUE FULL :-( (The
			 * command is retried after BUSY). Also update our
			 * queue size to the number of currently issued
			 * commands now.
			 */
			/* ++Andreas: the mid level code knows about
			   QUEUE_FULL now. */
			TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
			TAG_PRINTK("scsi%d: target %d lun %d returned "
				   "QUEUE_FULL after %d commands\n",
				   HOSTNO, cmd->device->id, cmd->device->lun,
				   ta->nr_allocated);
			if (ta->queue_size > ta->nr_allocated)
			    ta->nr_allocated = ta->queue_size;
		    }
#else
		    hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);

		    /* 
		     * I'm not sure what the correct thing to do here is : 
		     * 
		     * If the command that just executed is NOT a request 
		     * sense, the obvious thing to do is to set the result
		     * code to the values of the stored parameters.
		     * 
		     * If it was a REQUEST SENSE command, we need some way to
		     * differentiate between the failure code of the original
		     * and the failure code of the REQUEST sense - the obvious
		     * case is success, where we fall through and leave the
		     * result code unchanged.
		     * 
		     * The non-obvious place is where the REQUEST SENSE failed
		     */

		    if (cmd->cmnd[0] != REQUEST_SENSE) 
			cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8); 
		    else if (status_byte(cmd->SCp.Status) != GOOD)
			cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
		    
#ifdef AUTOSENSE
		    if ((cmd->cmnd[0] != REQUEST_SENSE) && 
			(status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
			ASEN_PRINTK("scsi%d: performing request sense\n",
				    HOSTNO);
			cmd->cmnd[0] = REQUEST_SENSE;
			cmd->cmnd[1] &= 0xe0;
			cmd->cmnd[2] = 0;
			cmd->cmnd[3] = 0;
			cmd->cmnd[4] = sizeof(cmd->sense_buffer);
			cmd->cmnd[5] = 0;
			cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);

			cmd->use_sg = 0;
			/* this is initialized from initialize_SCp 
			cmd->SCp.buffer = NULL;
			cmd->SCp.buffers_residual = 0;
			*/
			cmd->request_buffer = (char *) cmd->sense_buffer;
			cmd->request_bufflen = sizeof(cmd->sense_buffer);

			local_irq_save(flags);
			LIST(cmd,hostdata->issue_queue);
			NEXT(cmd) = hostdata->issue_queue;
		        hostdata->issue_queue = (Scsi_Cmnd *) cmd;
		        local_irq_restore(flags);
			QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
				  "issue queue\n", H_NO(cmd));
		   } else
#endif /* def AUTOSENSE */
		   {
#ifdef NCR5380_STATS
		       collect_stats(hostdata, cmd);
#endif
		       cmd->scsi_done(cmd);
		    }

		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    /* 
		     * Restore phase bits to 0 so an interrupted selection, 
		     * arbitration can resume.
		     */
		    NCR5380_write(TARGET_COMMAND_REG, 0);
		    
		    while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
			barrier();

		    falcon_dont_release--;
		    /* ++roman: For Falcon SCSI, release the lock on the
		     * ST-DMA here if no other commands are waiting on the
		     * disconnected queue.
		     */
		    falcon_release_lock_if_possible( hostdata );
		    return;
		case MESSAGE_REJECT:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    switch (hostdata->last_message) {
		    case HEAD_OF_QUEUE_TAG:
		    case ORDERED_QUEUE_TAG:
		    case SIMPLE_QUEUE_TAG:
			/* The target obviously doesn't support tagged
			 * queuing, even though it announced this ability in
			 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
			 * clear 'tagged_supported' and lock the LUN, since
			 * the command is treated as untagged further on.
			 */
			cmd->device->tagged_supported = 0;
			hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
			cmd->tag = TAG_NONE;
			TAG_PRINTK("scsi%d: target %d lun %d rejected "
				   "QUEUE_TAG message; tagged queuing "
				   "disabled\n",
				   HOSTNO, cmd->device->id, cmd->device->lun);
			break;
		    }
		    break;
		case DISCONNECT:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    local_irq_save(flags);
		    cmd->device->disconnect = 1;
		    LIST(cmd,hostdata->disconnected_queue);
		    NEXT(cmd) = hostdata->disconnected_queue;
		    hostdata->connected = NULL;
		    hostdata->disconnected_queue = cmd;
		    local_irq_restore(flags);
		    QU_PRINTK("scsi%d: command for target %d lun %d was "
			      "moved from connected to the "
			      "disconnected_queue\n", HOSTNO, 
			      cmd->device->id, cmd->device->lun);
		    /* 
		     * Restore phase bits to 0 so an interrupted selection, 
		     * arbitration can resume.
		     */
		    NCR5380_write(TARGET_COMMAND_REG, 0);

		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    /* Wait for bus free to avoid nasty timeouts */
		    while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
		    	barrier();
		    return;
		/* 
		 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
		 * operation, in violation of the SCSI spec so we can safely 
		 * ignore SAVE/RESTORE pointers calls.
		 *
		 * Unfortunately, some disks violate the SCSI spec and 
		 * don't issue the required SAVE_POINTERS message before
		 * disconnecting, and we have to break spec to remain 
		 * compatible.
		 */
		case SAVE_POINTERS:
		case RESTORE_POINTERS:
		    /* Accept message by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		    /* Enable reselect interrupts */
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    break;
		case EXTENDED_MESSAGE:
/* 
 * Extended messages are sent in the following format :
 * Byte 	
 * 0		EXTENDED_MESSAGE == 1
 * 1		length (includes one byte for code, doesn't 
 *		include first two bytes)
 * 2 		code
 * 3..length+1	arguments
 *
 * Start the extended message buffer with the EXTENDED_MESSAGE
 * byte, since print_msg() wants the whole thing.  
 */
		    extended_msg[0] = EXTENDED_MESSAGE;
		    /* Accept first byte by clearing ACK */
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

		    EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);

		    len = 2;
		    data = extended_msg + 1;
		    phase = PHASE_MSGIN;
		    NCR5380_transfer_pio(instance, &phase, &len, &data);
		    EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
			       (int)extended_msg[1], (int)extended_msg[2]);

		    if (!len && extended_msg[1] <= 
			(sizeof (extended_msg) - 1)) {
			/* Accept third byte by clearing ACK */
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
			len = extended_msg[1] - 1;
			data = extended_msg + 3;
			phase = PHASE_MSGIN;

			NCR5380_transfer_pio(instance, &phase, &len, &data);
			EXT_PRINTK("scsi%d: message received, residual %d\n",
				   HOSTNO, len);

			switch (extended_msg[2]) {
			case EXTENDED_SDTR:
			case EXTENDED_WDTR:
			case EXTENDED_MODIFY_DATA_POINTER:
			case EXTENDED_EXTENDED_IDENTIFY:
			    tmp = 0;
			}
		    } else if (len) {
			printk(KERN_NOTICE "scsi%d: error receiving "
			       "extended message\n", HOSTNO);
			tmp = 0;
		    } else {
			printk(KERN_NOTICE "scsi%d: extended message "
			       "code %02x length %d is too long\n",
			       HOSTNO, extended_msg[2], extended_msg[1]);
			tmp = 0;
		    }
		/* Fall through to reject message */

		/* 
  		 * If we get something weird that we aren't expecting, 
 		 * reject it.
		 */
		default:
		    if (!tmp) {
			printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
			print_msg (extended_msg);
			printk("\n");
		    } else if (tmp != EXTENDED_MESSAGE)
			printk(KERN_DEBUG "scsi%d: rejecting unknown "
			       "message %02x from target %d, lun %d\n",
			       HOSTNO, tmp, cmd->device->id, cmd->device->lun);
		    else
			printk(KERN_DEBUG "scsi%d: rejecting unknown "
			       "extended message "
			       "code %02x, length %d from target %d, lun %d\n",
			       HOSTNO, extended_msg[1], extended_msg[0],
			       cmd->device->id, cmd->device->lun);
   

		    msgout = MESSAGE_REJECT;
		    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | 
			ICR_ASSERT_ATN);
		    break;
		} /* switch (tmp) */
		break;
	    case PHASE_MSGOUT:
		len = 1;
		data = &msgout;
		hostdata->last_message = msgout;
		NCR5380_transfer_pio(instance, &phase, &len, &data);
		if (msgout == ABORT) {
#ifdef SUPPORT_TAGS
		    cmd_free_tag( cmd );
#else
		    hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
		    hostdata->connected = NULL;
		    cmd->result = DID_ERROR << 16;
#ifdef NCR5380_STATS
		    collect_stats(hostdata, cmd);
#endif
		    cmd->scsi_done(cmd);
		    NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		    falcon_release_lock_if_possible( hostdata );
		    return;
		}
		msgout = NOP;
		break;
	    case PHASE_CMDOUT:
		len = cmd->cmd_len;
		data = cmd->cmnd;
		/* 
		 * XXX for performance reasons, on machines with a 
		 * PSEUDO-DMA architecture we should probably 
		 * use the dma transfer function.  
		 */
		NCR5380_transfer_pio(instance, &phase, &len, 
		    &data);
		break;
	    case PHASE_STATIN:
		len = 1;
		data = &tmp;
		NCR5380_transfer_pio(instance, &phase, &len, &data);
		cmd->SCp.Status = tmp;
		break;
	    default:
		printk("scsi%d: unknown phase\n", HOSTNO);
		NCR_PRINT(NDEBUG_ANY);
	    } /* switch(phase) */
	} /* if (tmp * SR_REQ) */ 
    } /* while (1) */
}

/*
 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
 *
 * Purpose : does reselection, initializing the instance->connected 
 *	field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q 
 *	nexus has been reestablished,
 *	
 * Inputs : instance - this instance of the NCR5380.
 *
 */


static void NCR5380_reselect (struct Scsi_Host *instance)
{
    SETUP_HOSTDATA(instance);
    unsigned char target_mask;
    unsigned char lun, phase;
    int len;
#ifdef SUPPORT_TAGS
    unsigned char tag;
#endif
    unsigned char msg[3];
    unsigned char *data;
    Scsi_Cmnd *tmp = NULL, *prev;
/*    unsigned long flags; */

    /*
     * Disable arbitration, etc. since the host adapter obviously
     * lost, and tell an interrupted NCR5380_select() to restart.
     */

    NCR5380_write(MODE_REG, MR_BASE);
    hostdata->restart_select = 1;

    target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);

    RSL_PRINTK("scsi%d: reselect\n", HOSTNO);

    /* 
     * At this point, we have detected that our SCSI ID is on the bus,
     * SEL is true and BSY was false for at least one bus settle delay
     * (400 ns).
     *
     * We must assert BSY ourselves, until the target drops the SEL
     * signal.
     */

    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
    
    while (NCR5380_read(STATUS_REG) & SR_SEL);
    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

    /*
     * Wait for target to go into MSGIN.
     */

    while (!(NCR5380_read(STATUS_REG) & SR_REQ));

    len = 1;
    data = msg;
    phase = PHASE_MSGIN;
    NCR5380_transfer_pio(instance, &phase, &len, &data);

    if (!(msg[0] & 0x80)) {
	printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
	print_msg(msg);
	do_abort(instance);
	return;
    }
    lun = (msg[0] & 0x07);

#ifdef SUPPORT_TAGS
    /* If the phase is still MSGIN, the target wants to send some more
     * messages. In case it supports tagged queuing, this is probably a
     * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
     */
    tag = TAG_NONE;
    if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
	/* Accept previous IDENTIFY message by clearing ACK */
	NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE );
	len = 2;
	data = msg+1;
	if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
	    msg[1] == SIMPLE_QUEUE_TAG)
	    tag = msg[2];
	TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
		   "reselection\n", HOSTNO, target_mask, lun, tag);
    }
#endif
    
    /* 
     * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we 
     * just reestablished, and remove it from the disconnected queue.
     */

    for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL; 
	 tmp; prev = tmp, tmp = NEXT(tmp) ) {
	if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
#ifdef SUPPORT_TAGS
	    && (tag == tmp->tag) 
#endif
	    ) {
	    /* ++guenther: prevent race with falcon_release_lock */
	    falcon_dont_release++;
	    if (prev) {
		REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
		NEXT(prev) = NEXT(tmp);
	    } else {
		REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
		hostdata->disconnected_queue = NEXT(tmp);
	    }
	    NEXT(tmp) = NULL;
	    break;
	}
    }
    
    if (!tmp) {
	printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
#ifdef SUPPORT_TAGS
		"tag %d "
#endif
		"not in disconnected_queue.\n",
		HOSTNO, target_mask, lun
#ifdef SUPPORT_TAGS
		, tag
#endif
		);
	/* 
	 * Since we have an established nexus that we can't do anything
	 * with, we must abort it.  
	 */
	do_abort(instance);
	return;
    }

    /* Accept message by clearing ACK */
    NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

    hostdata->connected = tmp;
    RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
	       HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
    falcon_dont_release--;
}


/*
 * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
 *
 * Purpose : abort a command
 *
 * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the 
 * 	host byte of the result field to, if zero DID_ABORTED is 
 *	used.
 *
 * Returns : 0 - success, -1 on failure.
 *
 * XXX - there is no way to abort the command that is currently 
 * 	 connected, you have to wait for it to complete.  If this is 
 *	 a problem, we could implement longjmp() / setjmp(), setjmp()
 * 	 called where the loop started in NCR5380_main().
 */

static
int NCR5380_abort (Scsi_Cmnd *cmd)
{
    struct Scsi_Host *instance = cmd->device->host;
    SETUP_HOSTDATA(instance);
    Scsi_Cmnd *tmp, **prev;
    unsigned long flags;

    printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
    print_Scsi_Cmnd (cmd);

    NCR5380_print_status (instance);

    local_irq_save(flags);
    
    if (!IS_A_TT() && !falcon_got_lock)
	printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
	       HOSTNO);

    ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
		NCR5380_read(BUS_AND_STATUS_REG),
		NCR5380_read(STATUS_REG));

#if 1
/* 
 * Case 1 : If the command is the currently executing command, 
 * we'll set the aborted flag and return control so that 
 * information transfer routine can exit cleanly.
 */

    if (hostdata->connected == cmd) {

	ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
/*
 * We should perform BSY checking, and make sure we haven't slipped
 * into BUS FREE.
 */

/*	NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
/* 
 * Since we can't change phases until we've completed the current 
 * handshake, we have to source or sink a byte of data if the current
 * phase is not MSGOUT.
 */

/* 
 * Return control to the executing NCR drive so we can clear the
 * aborted flag and get back into our main loop.
 */ 

	if (do_abort(instance) == 0) {
	  hostdata->aborted = 1;
	  hostdata->connected = NULL;
	  cmd->result = DID_ABORT << 16;
#ifdef SUPPORT_TAGS
	  cmd_free_tag( cmd );
#else
	  hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
	  local_irq_restore(flags);
	  cmd->scsi_done(cmd);
	  falcon_release_lock_if_possible( hostdata );
	  return SCSI_ABORT_SUCCESS;
	} else {
/*	  local_irq_restore(flags); */
	  printk("scsi%d: abort of connected command failed!\n", HOSTNO);
	  return SCSI_ABORT_ERROR;
	} 
   }
#endif

/* 
 * Case 2 : If the command hasn't been issued yet, we simply remove it 
 * 	    from the issue queue.
 */
    for (prev = (Scsi_Cmnd **) &(hostdata->issue_queue), 
	tmp = (Scsi_Cmnd *) hostdata->issue_queue;
	tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp) )
	if (cmd == tmp) {
	    REMOVE(5, *prev, tmp, NEXT(tmp));
	    (*prev) = NEXT(tmp);
	    NEXT(tmp) = NULL;
	    tmp->result = DID_ABORT << 16;
	    local_irq_restore(flags);
	    ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
			HOSTNO);
	    /* Tagged queuing note: no tag to free here, hasn't been assigned
	     * yet... */
	    tmp->scsi_done(tmp);
	    falcon_release_lock_if_possible( hostdata );
	    return SCSI_ABORT_SUCCESS;
	}

/* 
 * Case 3 : If any commands are connected, we're going to fail the abort
 *	    and let the high level SCSI driver retry at a later time or 
 *	    issue a reset.
 *
 *	    Timeouts, and therefore aborted commands, will be highly unlikely
 *          and handling them cleanly in this situation would make the common
 *	    case of noresets less efficient, and would pollute our code.  So,
 *	    we fail.
 */

    if (hostdata->connected) {
	local_irq_restore(flags);
	ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
        return SCSI_ABORT_SNOOZE;
    }

/*
 * Case 4: If the command is currently disconnected from the bus, and 
 * 	there are no connected commands, we reconnect the I_T_L or 
 *	I_T_L_Q nexus associated with it, go into message out, and send 
 *      an abort message.
 *
 * This case is especially ugly. In order to reestablish the nexus, we
 * need to call NCR5380_select().  The easiest way to implement this 
 * function was to abort if the bus was busy, and let the interrupt
 * handler triggered on the SEL for reselect take care of lost arbitrations
 * where necessary, meaning interrupts need to be enabled.
 *
 * When interrupts are enabled, the queues may change - so we 
 * can't remove it from the disconnected queue before selecting it
 * because that could cause a failure in hashing the nexus if that 
 * device reselected.
 * 
 * Since the queues may change, we can't use the pointers from when we
 * first locate it.
 *
 * So, we must first locate the command, and if NCR5380_select()
 * succeeds, then issue the abort, relocate the command and remove
 * it from the disconnected queue.
 */

    for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
	 tmp = NEXT(tmp)) 
        if (cmd == tmp) {
            local_irq_restore(flags);
	    ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
  
            if (NCR5380_select (instance, cmd, (int) cmd->tag)) 
		return SCSI_ABORT_BUSY;

	    ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);

	    do_abort (instance);

	    local_irq_save(flags);
	    for (prev = (Scsi_Cmnd **) &(hostdata->disconnected_queue), 
		tmp = (Scsi_Cmnd *) hostdata->disconnected_queue;
		tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp) )
		    if (cmd == tmp) {
		    REMOVE(5, *prev, tmp, NEXT(tmp));
		    *prev = NEXT(tmp);
		    NEXT(tmp) = NULL;
		    tmp->result = DID_ABORT << 16;
		    /* We must unlock the tag/LUN immediately here, since the
		     * target goes to BUS FREE and doesn't send us another
		     * message (COMMAND_COMPLETE or the like)
		     */
#ifdef SUPPORT_TAGS
		    cmd_free_tag( tmp );
#else
		    hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
		    local_irq_restore(flags);
		    tmp->scsi_done(tmp);
		    falcon_release_lock_if_possible( hostdata );
		    return SCSI_ABORT_SUCCESS;
		}
	}

/*
 * Case 5 : If we reached this point, the command was not found in any of 
 *	    the queues.
 *
 * We probably reached this point because of an unlikely race condition
 * between the command completing successfully and the abortion code,
 * so we won't panic, but we will notify the user in case something really
 * broke.
 */

    local_irq_restore(flags);
    printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully\n"
           KERN_INFO "        before abortion\n", HOSTNO); 

/* Maybe it is sufficient just to release the ST-DMA lock... (if
 * possible at all) At least, we should check if the lock could be
 * released after the abort, in case it is kept due to some bug.
 */
    falcon_release_lock_if_possible( hostdata );

    return SCSI_ABORT_NOT_RUNNING;
}


/* 
 * Function : int NCR5380_reset (Scsi_Cmnd *cmd)
 * 
 * Purpose : reset the SCSI bus.
 *
 * Returns : SCSI_RESET_WAKEUP
 *
 */ 

static int NCR5380_bus_reset( Scsi_Cmnd *cmd)
{
    SETUP_HOSTDATA(cmd->device->host);
    int           i;
    unsigned long flags;
#if 1
    Scsi_Cmnd *connected, *disconnected_queue;
#endif

    if (!IS_A_TT() && !falcon_got_lock)
	printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
	       H_NO(cmd) );

    NCR5380_print_status (cmd->device->host);

    /* get in phase */
    NCR5380_write( TARGET_COMMAND_REG,
		   PHASE_SR_TO_TCR( NCR5380_read(STATUS_REG) ));
    /* assert RST */
    NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST );
    udelay (40);
    /* reset NCR registers */
    NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE );
    NCR5380_write( MODE_REG, MR_BASE );
    NCR5380_write( TARGET_COMMAND_REG, 0 );
    NCR5380_write( SELECT_ENABLE_REG, 0 );
    /* ++roman: reset interrupt condition! otherwise no interrupts don't get
     * through anymore ... */
    (void)NCR5380_read( RESET_PARITY_INTERRUPT_REG );

#if 1 /* XXX Should now be done by midlevel code, but it's broken XXX */
      /* XXX see below                                            XXX */

    /* MSch: old-style reset: actually abort all command processing here */

    /* After the reset, there are no more connected or disconnected commands
     * and no busy units; to avoid problems with re-inserting the commands
     * into the issue_queue (via scsi_done()), the aborted commands are
     * remembered in local variables first.
     */
    local_irq_save(flags);
    connected = (Scsi_Cmnd *)hostdata->connected;
    hostdata->connected = NULL;
    disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
    hostdata->disconnected_queue = NULL;
#ifdef SUPPORT_TAGS
    free_all_tags();
#endif
    for( i = 0; i < 8; ++i )
	hostdata->busy[i] = 0;
#ifdef REAL_DMA
    hostdata->dma_len = 0;
#endif
    local_irq_restore(flags);

    /* In order to tell the mid-level code which commands were aborted, 
     * set the command status to DID_RESET and call scsi_done() !!!
     * This ultimately aborts processing of these commands in the mid-level.
     */

    if ((cmd = connected)) {
	ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
	cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
	cmd->scsi_done( cmd );
    }

    for (i = 0; (cmd = disconnected_queue); ++i) {
	disconnected_queue = NEXT(cmd);
	NEXT(cmd) = NULL;
	cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
	cmd->scsi_done( cmd );
    }
    if (i > 0)
	ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);

/* The Falcon lock should be released after a reset...
 */
/* ++guenther: moved to atari_scsi_reset(), to prevent a race between
 * unlocking and enabling dma interrupt.
 */
/*    falcon_release_lock_if_possible( hostdata );*/

    /* since all commands have been explicitly terminated, we need to tell
     * the midlevel code that the reset was SUCCESSFUL, and there is no 
     * need to 'wake up' the commands by a request_sense
     */
    return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
#else /* 1 */

    /* MSch: new-style reset handling: let the mid-level do what it can */

    /* ++guenther: MID-LEVEL IS STILL BROKEN.
     * Mid-level is supposed to requeue all commands that were active on the
     * various low-level queues. In fact it does this, but that's not enough
     * because all these commands are subject to timeout. And if a timeout
     * happens for any removed command, *_abort() is called but all queues
     * are now empty. Abort then gives up the falcon lock, which is fatal,
     * since the mid-level will queue more commands and must have the lock
     * (it's all happening inside timer interrupt handler!!).
     * Even worse, abort will return NOT_RUNNING for all those commands not
     * on any queue, so they won't be retried ...
     *
     * Conclusion: either scsi.c disables timeout for all resetted commands
     * immediately, or we lose!  As of linux-2.0.20 it doesn't.
     */

    /* After the reset, there are no more connected or disconnected commands
     * and no busy units; so clear the low-level status here to avoid 
     * conflicts when the mid-level code tries to wake up the affected 
     * commands!
     */

    if (hostdata->issue_queue)
	ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
    if (hostdata->connected) 
	ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
    if (hostdata->disconnected_queue)
	ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));

    local_irq_save(flags);
    hostdata->issue_queue = NULL;
    hostdata->connected = NULL;
    hostdata->disconnected_queue = NULL;
#ifdef SUPPORT_TAGS
    free_all_tags();
#endif
    for( i = 0; i < 8; ++i )
	hostdata->busy[i] = 0;
#ifdef REAL_DMA
    hostdata->dma_len = 0;
#endif
    local_irq_restore(flags);

    /* we did no complete reset of all commands, so a wakeup is required */
    return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
#endif /* 1 */
}

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