NCR5380.c

						dprintk(NDEBUG_AUTOSENSE, "scsi%d : performing request sense\n", instance->host_no);

						LIST(cmd, hostdata->issue_queue);
						cmd->host_scribble = (unsigned char *)
						    hostdata->issue_queue;
						hostdata->issue_queue = (struct scsi_cmnd *) cmd;
						dprintk(NDEBUG_QUEUES, "scsi%d : REQUEST SENSE added to head of issue queue\n", instance->host_no);
					} else {
						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();
					return;
				case MESSAGE_REJECT:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					switch (hostdata->last_message) {
					case HEAD_OF_QUEUE_TAG:
					case ORDERED_QUEUE_TAG:
					case SIMPLE_QUEUE_TAG:
						cmd->device->simple_tags = 0;
						hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
						break;
					default:
						break;
					}
				case DISCONNECT:{
						/* Accept message by clearing ACK */
						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
						LIST(cmd, hostdata->disconnected_queue);
						cmd->host_scribble = (unsigned char *)
						    hostdata->disconnected_queue;
						hostdata->connected = NULL;
						hostdata->disconnected_queue = cmd;
						dprintk(NDEBUG_QUEUES, "scsi%d : command for target %d lun %llu was moved from connected to" "  the disconnected_queue\n", instance->host_no, 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 - FIXME timeout !*/
						/* NCR538_poll_politely(instance, STATUS_REG, SR_BSY, 0, 30 * HZ); */
						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);
					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 spi_print_msg() wants the whole thing.  
 */
					extended_msg[0] = EXTENDED_MESSAGE;
					/* Accept first byte by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					dprintk(NDEBUG_EXTENDED, "scsi%d : receiving extended message\n", instance->host_no);

					len = 2;
					data = extended_msg + 1;
					phase = PHASE_MSGIN;
					NCR5380_transfer_pio(instance, &phase, &len, &data);

					dprintk(NDEBUG_EXTENDED, "scsi%d : length=%d, code=0x%02x\n", instance->host_no, (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);
						dprintk(NDEBUG_EXTENDED, "scsi%d : message received, residual %d\n", instance->host_no, 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("scsi%d: error receiving extended message\n", instance->host_no);
						tmp = 0;
					} else {
						printk("scsi%d: extended message code %02x length %d is too long\n", instance->host_no, 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("scsi%d: rejecting message ", instance->host_no);
						spi_print_msg(extended_msg);
						printk("\n");
					} else if (tmp != EXTENDED_MESSAGE)
						scmd_printk(KERN_INFO, cmd,
							"rejecting unknown message %02x\n",tmp);
					else
						scmd_printk(KERN_INFO, cmd,
							"rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);

					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) {
					hostdata->busy[cmd->device->id] &= ~(1 << (cmd->device->lun & 0xFF));
					hostdata->connected = NULL;
					cmd->result = DID_ERROR << 16;
					cmd->scsi_done(cmd);
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
					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", instance->host_no);
				NCR5380_dprint(NDEBUG_ANY, instance);
			}	/* switch(phase) */
		} else {
			spin_unlock_irq(instance->host_lock);
			NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
			spin_lock_irq(instance->host_lock);
		}
	}			/* 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.
 *
 * Locks: io_request_lock held by caller if IRQ driven
 */

static void NCR5380_reselect(struct Scsi_Host *instance) {
	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *)
	 instance->hostdata;
	unsigned char target_mask;
	unsigned char lun, phase;
	int len;
	unsigned char msg[3];
	unsigned char *data;
	struct scsi_cmnd *tmp = NULL, *prev;
	int abort = 0;

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

	NCR5380_write(MODE_REG, MR_BASE);

	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
	dprintk(NDEBUG_SELECTION, "scsi%d : reselect\n", instance->host_no);

	/* 
	 * 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);

	/* FIXME: timeout too long, must fail to workqueue */	
	if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
		abort = 1;
		
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

	/*
	 * Wait for target to go into MSGIN.
	 * FIXME: timeout needed and fail to work queeu
	 */

	if(NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 2*HZ))
		abort = 1;

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

	if (!(msg[0] & 0x80)) {
		printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
		spi_print_msg(msg);
		abort = 1;
	} else {
		/* Accept message by clearing ACK */
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		lun = (msg[0] & 0x07);

		/* 
		 * We need to add code for SCSI-II to track which devices have
		 * I_T_L_Q nexuses established, and which have simple I_T_L
		 * nexuses so we can chose to do additional data transfer.
		 */

		/* 
		 * 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 = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (struct scsi_cmnd *) tmp->host_scribble)
			if ((target_mask == (1 << tmp->device->id)) && (lun == (u8)tmp->device->lun)
			    ) {
				if (prev) {
					REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
					prev->host_scribble = tmp->host_scribble;
				} else {
					REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
					hostdata->disconnected_queue = (struct scsi_cmnd *) tmp->host_scribble;
				}
				tmp->host_scribble = NULL;
				break;
			}
		if (!tmp) {
			printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
			/* 
			 * Since we have an established nexus that we can't do anything with,
			 * we must abort it.  
			 */
			abort = 1;
		}
	}

	if (abort) {
		do_abort(instance);
	} else {
		hostdata->connected = tmp;
		dprintk(NDEBUG_RESELECTION, "scsi%d : nexus established, target = %d, lun = %llu, tag = %d\n", instance->host_no, tmp->device->id, tmp->device->lun, tmp->tag);
	}
}

/*
 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
 *
 * Purpose : called by interrupt handler when DMA finishes or a phase
 *      mismatch occurs (which would finish the DMA transfer).  
 *
 * Inputs : instance - this instance of the NCR5380.
 *
 * Returns : pointer to the scsi_cmnd structure for which the I_T_L
 *      nexus has been reestablished, on failure NULL is returned.
 */

#ifdef REAL_DMA
static void NCR5380_dma_complete(NCR5380_instance * instance) {
	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
	int transferred;

	/*
	 * XXX this might not be right.
	 *
	 * Wait for final byte to transfer, ie wait for ACK to go false.
	 *
	 * We should use the Last Byte Sent bit, unfortunately this is 
	 * not available on the 5380/5381 (only the various CMOS chips)
	 *
	 * FIXME: timeout, and need to handle long timeout/irq case
	 */

	NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);

	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

	/*
	 * The only places we should see a phase mismatch and have to send
	 * data from the same set of pointers will be the data transfer
	 * phases.  So, residual, requested length are only important here.
	 */

	if (!(hostdata->connected->SCp.phase & SR_CD)) {
		transferred = instance->dmalen - NCR5380_dma_residual();
		hostdata->connected->SCp.this_residual -= transferred;
		hostdata->connected->SCp.ptr += transferred;
	}
}
#endif				/* def REAL_DMA */

/*
 * Function : int NCR5380_abort (struct 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 : SUCCESS - success, FAILED 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().
 *
 * Locks: host lock taken by caller
 */

static int NCR5380_abort(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *instance = cmd->device->host;
	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
	struct scsi_cmnd *tmp, **prev;

	scmd_printk(KERN_WARNING, cmd, "aborting command\n");

	spin_lock_irq(instance->host_lock);
	NCR5380_print_status(instance);

	dprintk(NDEBUG_ABORT, "scsi%d : abort called\n", instance->host_no);
	dprintk(NDEBUG_ABORT, "        basr 0x%X, sr 0x%X\n", NCR5380_read(BUS_AND_STATUS_REG), NCR5380_read(STATUS_REG));

#if 0
/*
 * 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) {
		dprintk(NDEBUG_ABORT, "scsi%d : aborting connected command\n", instance->host_no);
/*
 * 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.
 */

		return SUCCESS;
	}
#endif

/* 
 * Case 2 : If the command hasn't been issued yet, we simply remove it 
 *          from the issue queue.
 */
 
	dprintk(NDEBUG_ABORT, "scsi%d : abort going into loop.\n", instance->host_no);
	for (prev = (struct scsi_cmnd **) &(hostdata->issue_queue), tmp = (struct scsi_cmnd *) hostdata->issue_queue; tmp; prev = (struct scsi_cmnd **) &(tmp->host_scribble), tmp = (struct scsi_cmnd *) tmp->host_scribble)
		if (cmd == tmp) {
			REMOVE(5, *prev, tmp, tmp->host_scribble);
			(*prev) = (struct scsi_cmnd *) tmp->host_scribble;
			tmp->host_scribble = NULL;
			spin_unlock_irq(instance->host_lock);
			tmp->result = DID_ABORT << 16;
			dprintk(NDEBUG_ABORT, "scsi%d : abort removed command from issue queue.\n", instance->host_no);
			tmp->scsi_done(tmp);
			return SUCCESS;
		}
#if (NDEBUG  & NDEBUG_ABORT)
	/* KLL */
		else if (prev == tmp)
			printk(KERN_ERR "scsi%d : LOOP\n", instance->host_no);
#endif

/* 
 * 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) {
		spin_unlock_irq(instance->host_lock);
		dprintk(NDEBUG_ABORT, "scsi%d : abort failed, command connected.\n", instance->host_no);
		return FAILED;
	}
/*
 * 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 = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp; tmp = (struct scsi_cmnd *) tmp->host_scribble)
		if (cmd == tmp) {
			dprintk(NDEBUG_ABORT, "scsi%d : aborting disconnected command.\n", instance->host_no);

			if (NCR5380_select(instance, cmd)) {
				spin_unlock_irq(instance->host_lock);
				return FAILED;
			}
			dprintk(NDEBUG_ABORT, "scsi%d : nexus reestablished.\n", instance->host_no);

			do_abort(instance);

			for (prev = (struct scsi_cmnd **) &(hostdata->disconnected_queue), tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp; prev = (struct scsi_cmnd **) &(tmp->host_scribble), tmp = (struct scsi_cmnd *) tmp->host_scribble)
				if (cmd == tmp) {
					REMOVE(5, *prev, tmp, tmp->host_scribble);
					*prev = (struct scsi_cmnd *) tmp->host_scribble;
					tmp->host_scribble = NULL;
					spin_unlock_irq(instance->host_lock);
					tmp->result = DID_ABORT << 16;
					tmp->scsi_done(tmp);
					return 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.
 */
	spin_unlock_irq(instance->host_lock);
	printk(KERN_WARNING "scsi%d : warning : SCSI command probably completed successfully\n"
			"         before abortion\n", instance->host_no);
	return FAILED;
}


/**
 * NCR5380_bus_reset - reset the SCSI bus
 * @cmd: SCSI command undergoing EH
 *
 * Returns SUCCESS
 */

static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *instance = cmd->device->host;

	spin_lock_irq(instance->host_lock);

#if (NDEBUG & NDEBUG_ANY)
	scmd_printk(KERN_INFO, cmd, "performing bus reset\n");
	NCR5380_print_status(instance);
#endif

	do_reset(instance);

	spin_unlock_irq(instance->host_lock);

	return SUCCESS;
}