nsp32.c

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	/*
	 * set TRANSFER CONTROL REG
	 */
	transfer = 0;
	transfer |= (TRANSFER_GO | ALL_COUNTER_CLR);
	if (data->trans_method & NSP32_TRANSFER_BUSMASTER) {
		if (scsi_bufflen(SCpnt) > 0) {
			transfer |= BM_START;
		}
	} else if (data->trans_method & NSP32_TRANSFER_MMIO) {
		transfer |= CB_MMIO_MODE;
	} else if (data->trans_method & NSP32_TRANSFER_PIO) {
		transfer |= CB_IO_MODE;
	}
	nsp32_write2(base, TRANSFER_CONTROL, transfer);

	/*
	 * restart AutoSCSI
	 *
	 * TODO: COMMANDCONTROL_AUTO_COMMAND_PHASE is needed ?
	 */
	command |= (CLEAR_CDB_FIFO_POINTER |
		    AUTO_COMMAND_PHASE     |
		    AUTOSCSI_RESTART       );
	nsp32_write2(base, COMMAND_CONTROL, command);

	nsp32_dbg(NSP32_DEBUG_RESTART, "exit");
}


/*
 * cannot run automatically message in occur
 */
static void nsp32_msgin_occur(struct scsi_cmnd     *SCpnt,
			      unsigned long  irq_status,
			      unsigned short execph)
{
	nsp32_hw_data *data = (nsp32_hw_data *)SCpnt->device->host->hostdata;
	unsigned int   base = SCpnt->device->host->io_port;
	unsigned char  msg;
	unsigned char  msgtype;
	unsigned char  newlun;
	unsigned short command  = 0;
	int            msgclear = TRUE;
	long           new_sgtp;
	int            ret;

	/*
	 * read first message
	 *    Use SCSIDATA_W_ACK instead of SCSIDATAIN, because the procedure
	 *    of Message-In have to be processed before sending back SCSI ACK.
	 */
	msg = nsp32_read1(base, SCSI_DATA_IN);
	data->msginbuf[(unsigned char)data->msgin_len] = msg;
	msgtype = data->msginbuf[0];
	nsp32_dbg(NSP32_DEBUG_MSGINOCCUR,
		  "enter: msglen: 0x%x msgin: 0x%x msgtype: 0x%x",
		  data->msgin_len, msg, msgtype);

	/*
	 * TODO: We need checking whether bus phase is message in?
	 */

	/*
	 * assert SCSI ACK
	 */
	nsp32_sack_assert(data);

	/*
	 * processing IDENTIFY
	 */
	if (msgtype & 0x80) {
		if (!(irq_status & IRQSTATUS_RESELECT_OCCUER)) {
			/* Invalid (non reselect) phase */
			goto reject;
		}

		newlun = msgtype & 0x1f; /* TODO: SPI-3 compliant? */
		ret = nsp32_reselection(SCpnt, newlun);
		if (ret == TRUE) {
			goto restart;
		} else {
			goto reject;
		}
	}
	
	/*
	 * processing messages except for IDENTIFY
	 *
	 * TODO: Messages are all SCSI-2 terminology. SCSI-3 compliance is TODO.
	 */
	switch (msgtype) {
	/*
	 * 1-byte message
	 */
	case COMMAND_COMPLETE:
	case DISCONNECT:
		/*
		 * These messages should not be occurred.
		 * They should be processed on AutoSCSI sequencer.
		 */
		nsp32_msg(KERN_WARNING, 
			   "unexpected message of AutoSCSI MsgIn: 0x%x", msg);
		break;
		
	case RESTORE_POINTERS:
		/*
		 * AutoMsgIn03 is disabled, and HBA gets this message.
		 */

		if ((execph & DATA_IN_PHASE) || (execph & DATA_OUT_PHASE)) {
			unsigned int s_sacklen;

			s_sacklen = nsp32_read4(base, SAVED_SACK_CNT);
			if ((execph & MSGIN_02_VALID) && (s_sacklen > 0)) {
				nsp32_adjust_busfree(SCpnt, s_sacklen);
			} else {
				/* No need to rewrite SGT */
			}
		}
		data->cur_lunt->msgin03 = FALSE;

		/* Update with the new value */

		/* reset SACK/SavedACK counter (or ALL clear?) */
		nsp32_write4(base, CLR_COUNTER, CLRCOUNTER_ALLMASK);

		/*
		 * set new sg pointer
		 */
		new_sgtp = data->cur_lunt->sglun_paddr + 
			(data->cur_lunt->cur_entry * sizeof(nsp32_sgtable));
		nsp32_write4(base, SGT_ADR, new_sgtp);

		break;

	case SAVE_POINTERS:
		/*
		 * These messages should not be occurred.
		 * They should be processed on AutoSCSI sequencer.
		 */
		nsp32_msg (KERN_WARNING, 
			   "unexpected message of AutoSCSI MsgIn: SAVE_POINTERS");
		
		break;
		
	case MESSAGE_REJECT:
		/* If previous message_out is sending SDTR, and get 
		   message_reject from target, SDTR negotiation is failed */
		if (data->cur_target->sync_flag &
				(SDTR_INITIATOR | SDTR_TARGET)) {
			/*
			 * Current target is negotiating SDTR, but it's
			 * failed.  Fall back to async transfer mode, and set
			 * SDTR_DONE.
			 */
			nsp32_set_async(data, data->cur_target);
			data->cur_target->sync_flag &= ~SDTR_INITIATOR;
			data->cur_target->sync_flag |= SDTR_DONE;

		}
		break;

	case LINKED_CMD_COMPLETE:
	case LINKED_FLG_CMD_COMPLETE:
		/* queue tag is not supported currently */
		nsp32_msg (KERN_WARNING, 
			   "unsupported message: 0x%x", msgtype);
		break;

	case INITIATE_RECOVERY:
		/* staring ECA (Extended Contingent Allegiance) state. */
		/* This message is declined in SPI2 or later. */

		goto reject;

	/*
	 * 2-byte message
	 */
	case SIMPLE_QUEUE_TAG:
	case 0x23:
		/*
		 * 0x23: Ignore_Wide_Residue is not declared in scsi.h.
		 * No support is needed.
		 */
		if (data->msgin_len >= 1) {
			goto reject;
		}

		/* current position is 1-byte of 2 byte */
		msgclear = FALSE;

		break;

	/*
	 * extended message
	 */
	case EXTENDED_MESSAGE:
		if (data->msgin_len < 1) {
			/*
			 * Current position does not reach 2-byte
			 * (2-byte is extended message length).
			 */
			msgclear = FALSE;
			break;
		}

		if ((data->msginbuf[1] + 1) > data->msgin_len) {
			/*
			 * Current extended message has msginbuf[1] + 2
			 * (msgin_len starts counting from 0, so buf[1] + 1).
			 * If current message position is not finished,
			 * continue receiving message.
			 */
			msgclear = FALSE;
			break;
		}

		/*
		 * Reach here means regular length of each type of 
		 * extended messages.
		 */
		switch (data->msginbuf[2]) {
		case EXTENDED_MODIFY_DATA_POINTER:
			/* TODO */
			goto reject; /* not implemented yet */
			break;

		case EXTENDED_SDTR:
			/*
			 * Exchange this message between initiator and target.
			 */
			if (data->msgin_len != EXTENDED_SDTR_LEN + 1) {
				/*
				 * received inappropriate message.
				 */
				goto reject;
				break;
			}

			nsp32_analyze_sdtr(SCpnt);

			break;

		case EXTENDED_EXTENDED_IDENTIFY:
			/* SCSI-I only, not supported. */
			goto reject; /* not implemented yet */

			break;

		case EXTENDED_WDTR:
			goto reject; /* not implemented yet */

			break;
			
		default:
			goto reject;
		}
		break;
		
	default:
		goto reject;
	}

 restart:
	if (msgclear == TRUE) {
		data->msgin_len = 0;

		/*
		 * If restarting AutoSCSI, but there are some message to out
		 * (msgout_len > 0), set AutoATN, and set SCSIMSGOUT as 0
		 * (MV_VALID = 0). When commandcontrol is written with
		 * AutoSCSI restart, at the same time MsgOutOccur should be
		 * happened (however, such situation is really possible...?).
		 */
		if (data->msgout_len > 0) {	
			nsp32_write4(base, SCSI_MSG_OUT, 0);
			command |= AUTO_ATN;
		}

		/*
		 * restart AutoSCSI
		 * If it's failed, COMMANDCONTROL_AUTO_COMMAND_PHASE is needed.
		 */
		command |= (AUTO_MSGIN_00_OR_04 | AUTO_MSGIN_02);

		/*
		 * If current msgin03 is TRUE, then flag on.
		 */
		if (data->cur_lunt->msgin03 == TRUE) {
			command |= AUTO_MSGIN_03;
		}
		data->cur_lunt->msgin03 = FALSE;
	} else {
		data->msgin_len++;
	}

	/*
	 * restart AutoSCSI
	 */
	nsp32_restart_autoscsi(SCpnt, command);

	/*
	 * wait SCSI REQ negate for REQ-ACK handshake
	 */
	nsp32_wait_req(data, NEGATE);

	/*
	 * negate SCSI ACK
	 */
	nsp32_sack_negate(data);

	nsp32_dbg(NSP32_DEBUG_MSGINOCCUR, "exit");

	return;

 reject:
	nsp32_msg(KERN_WARNING, 
		  "invalid or unsupported MessageIn, rejected. "
		  "current msg: 0x%x (len: 0x%x), processing msg: 0x%x",
		  msg, data->msgin_len, msgtype);
	nsp32_build_reject(SCpnt);
	data->msgin_len = 0;

	goto restart;
}

/*
 * 
 */
static void nsp32_analyze_sdtr(struct scsi_cmnd *SCpnt)
{
	nsp32_hw_data   *data = (nsp32_hw_data *)SCpnt->device->host->hostdata;
	nsp32_target     *target     = data->cur_target;
	nsp32_sync_table *synct;
	unsigned char     get_period = data->msginbuf[3];
	unsigned char     get_offset = data->msginbuf[4];
	int               entry;
	int               syncnum;

	nsp32_dbg(NSP32_DEBUG_MSGINOCCUR, "enter");

	synct   = data->synct;
	syncnum = data->syncnum;

	/*
	 * If this inititor sent the SDTR message, then target responds SDTR,
	 * initiator SYNCREG, ACKWIDTH from SDTR parameter.
	 * Messages are not appropriate, then send back reject message.
	 * If initiator did not send the SDTR, but target sends SDTR, 
	 * initiator calculator the appropriate parameter and send back SDTR.
	 */	
	if (target->sync_flag & SDTR_INITIATOR) {
		/*
		 * Initiator sent SDTR, the target responds and
		 * send back negotiation SDTR.
		 */
		nsp32_dbg(NSP32_DEBUG_MSGINOCCUR, "target responds SDTR");
	
		target->sync_flag &= ~SDTR_INITIATOR;
		target->sync_flag |= SDTR_DONE;

		/*
		 * offset:
		 */
		if (get_offset > SYNC_OFFSET) {
			/*
			 * Negotiation is failed, the target send back
			 * unexpected offset value.
			 */
			goto reject;
		}
		
		if (get_offset == ASYNC_OFFSET) {
			/*
			 * Negotiation is succeeded, the target want
			 * to fall back into asynchronous transfer mode.
			 */
			goto async;
		}

		/*
		 * period:
		 *    Check whether sync period is too short. If too short,
		 *    fall back to async mode. If it's ok, then investigate
		 *    the received sync period. If sync period is acceptable
		 *    between sync table start_period and end_period, then
		 *    set this I_T nexus as sent offset and period.
		 *    If it's not acceptable, send back reject and fall back
		 *    to async mode.
		 */
		if (get_period < data->synct[0].period_num) {
			/*
			 * Negotiation is failed, the target send back
			 * unexpected period value.
			 */
			goto reject;
		}

		entry = nsp32_search_period_entry(data, target, get_period);

		if (entry < 0) {
			/*
			 * Target want to use long period which is not 
			 * acceptable NinjaSCSI-32Bi/UDE.
			 */
			goto reject;
		}

		/*
		 * Set new sync table and offset in this I_T nexus.
		 */
		nsp32_set_sync_entry(data, target, entry, get_offset);
	} else {
		/* Target send SDTR to initiator. */
		nsp32_dbg(NSP32_DEBUG_MSGINOCCUR, "target send SDTR");
	
		target->sync_flag |= SDTR_INITIATOR;

		/* offset: */
		if (get_offset > SYNC_OFFSET) {
			/* send back as SYNC_OFFSET */
			get_offset = SYNC_OFFSET;
		}

		/* period: */
		if (get_period < data->synct[0].period_num) {
			get_period = data->synct[0].period_num;
		}

		entry = nsp32_search_period_entry(data, target, get_period);

		if (get_offset == ASYNC_OFFSET || entry < 0) {
			nsp32_set_async(data, target);
			nsp32_build_sdtr(SCpnt, 0, ASYNC_OFFSET);
		} else {
			nsp32_set_sync_entry(data, target, entry, get_offset);
			nsp32_build_sdtr(SCpnt, get_period, get_offset);
		}
	}

	target->period = get_period;
	nsp32_dbg(NSP32_DEBUG_MSGINOCCUR, "exit");
	return;

 reject:
	/*
	 * If the current message is unacceptable, send back to the target
	 * with reject message.
	 */
	nsp32_build_reject(SCpnt);

 async:
	nsp32_set_async(data, target);	/* set as ASYNC transfer mode */

	target->period = 0;
	nsp32_dbg(NSP32_DEBUG_MSGINOCCUR, "exit: set async");
	return;
}


/*
 * Search config entry number matched in sync_table from given
 * target and speed period value. If failed to search, return negative value.
 */
static int nsp32_search_period_entry(nsp32_hw_data *data,
				     nsp32_target  *target,
				     unsigned char  period)
{
	int i;

	if (target->limit_entry >= data->syncnum) {
		nsp32_msg(KERN_ERR, "limit_entry exceeds syncnum!");
		target->limit_entry = 0;
	}

	for (i = target->limit_entry; i < data->syncnum; i++) {
		if (period >