aic79xx.seq

linux2.6.16版本

		or	SIMODE1, ENBUSFREE;
	}
	mov	SAVED_SCSIID, SCB_SCSIID;
	mov	SAVED_LUN, SCB_LUN;
	mvi	SEQ_FLAGS, NO_CDB_SENT;
END_CRITICAL;
	or	SXFRCTL0, SPIOEN;

	/*
	 * As soon as we get a successful selection, the target
	 * should go into the message out phase since we have ATN
	 * asserted.
	 */
	mvi	MSG_OUT, MSG_IDENTIFYFLAG;

	/*
	 * Main loop for information transfer phases.  Wait for the
	 * target to assert REQ before checking MSG, C/D and I/O for
	 * the bus phase.
	 */
mesgin_phasemis:
ITloop:
	call	phase_lock;

	mov	A, LASTPHASE;

	test	A, ~P_DATAIN_DT	jz p_data;
	cmp	A,P_COMMAND	je p_command;
	cmp	A,P_MESGOUT	je p_mesgout;
	cmp	A,P_STATUS	je p_status;
	cmp	A,P_MESGIN	je p_mesgin;

	SET_SEQINTCODE(BAD_PHASE)
	jmp	ITloop;			/* Try reading the bus again. */

/*
 * Command phase.  Set up the DMA registers and let 'er rip.
 */
p_command:
	test	SEQ_FLAGS, NOT_IDENTIFIED jz p_command_okay;
	SET_SEQINTCODE(PROTO_VIOLATION)
p_command_okay:
	test	MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1))
		jnz p_command_allocate_fifo;
	/*
	 * Command retry.  Free our current FIFO and
	 * re-allocate a FIFO so transfer state is
	 * reset.
	 */
SET_SRC_MODE	M_DFF1;
SET_DST_MODE	M_DFF1;
	mvi	DFFSXFRCTL, RSTCHN|CLRSHCNT;
	SET_MODE(M_SCSI, M_SCSI)
p_command_allocate_fifo:
	bmov	ALLOCFIFO_SCBPTR, SCBPTR, 2;
	call	allocate_fifo;
SET_SRC_MODE	M_DFF1;
SET_DST_MODE	M_DFF1;
	add	NONE, -17, SCB_CDB_LEN;
	jnc	p_command_embedded;
p_command_from_host:
	bmov	HADDR[0], SCB_HOST_CDB_PTR, 9;
	mvi	SG_CACHE_PRE, LAST_SEG;
	mvi	DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN);
	jmp	p_command_xfer;
p_command_embedded:
	bmov	SHCNT[0], SCB_CDB_LEN,  1;
	bmov	DFDAT, SCB_CDB_STORE, 16; 
	mvi	DFCNTRL, SCSIEN;
p_command_xfer:
	and	SEQ_FLAGS, ~NO_CDB_SENT;
	if ((ahd->features & AHD_FAST_CDB_DELIVERY) != 0) {
		/*
		 * To speed up CDB delivery in Rev B, all CDB acks
		 * are "released" to the output sync as soon as the
		 * command phase starts.  There is only one problem
		 * with this approach.  If the target changes phase
		 * before all data are sent, we have left over acks
		 * that can go out on the bus in a data phase.  Due
		 * to other chip contraints, this only happens if
		 * the target goes to data-in, but if the acks go
		 * out before we can test SDONE, we'll think that
		 * the transfer has completed successfully.  Work
		 * around this by taking advantage of the 400ns or
		 * 800ns dead time between command phase and the REQ
		 * of the new phase.  If the transfer has completed
		 * successfully, SCSIEN should fall *long* before we
		 * see a phase change.  We thus treat any phasemiss
		 * that occurs before SCSIEN falls as an incomplete
		 * transfer.
		 */
		test	SSTAT1, PHASEMIS jnz p_command_xfer_failed;
		test	DFCNTRL, SCSIEN jnz . - 1;
	} else {
		test	DFCNTRL, SCSIEN jnz .;
	}
	/*
	 * DMA Channel automatically disabled.
	 * Don't allow a data phase if the command
	 * was not fully transferred.
	 */
	test	SSTAT2, SDONE jnz ITloop;
p_command_xfer_failed:
	or	SEQ_FLAGS, NO_CDB_SENT;
	jmp	ITloop;


/*
 * Status phase.  Wait for the data byte to appear, then read it
 * and store it into the SCB.
 */
SET_SRC_MODE	M_SCSI;
SET_DST_MODE	M_SCSI;
p_status:
	test	SEQ_FLAGS,NOT_IDENTIFIED jnz mesgin_proto_violation;
p_status_okay:
	mov	SCB_SCSI_STATUS, SCSIDAT;
	or	SCB_CONTROL, STATUS_RCVD;
	jmp	ITloop;

/*
 * Message out phase.  If MSG_OUT is MSG_IDENTIFYFLAG, build a full
 * indentify message sequence and send it to the target.  The host may
 * override this behavior by setting the MK_MESSAGE bit in the SCB
 * control byte.  This will cause us to interrupt the host and allow
 * it to handle the message phase completely on its own.  If the bit
 * associated with this target is set, we will also interrupt the host,
 * thereby allowing it to send a message on the next selection regardless
 * of the transaction being sent.
 * 
 * If MSG_OUT is == HOST_MSG, also interrupt the host and take a message.
 * This is done to allow the host to send messages outside of an identify
 * sequence while protecting the seqencer from testing the MK_MESSAGE bit
 * on an SCB that might not be for the current nexus. (For example, a
 * BDR message in responce to a bad reselection would leave us pointed to
 * an SCB that doesn't have anything to do with the current target).
 *
 * Otherwise, treat MSG_OUT as a 1 byte message to send (abort, abort tag,
 * bus device reset).
 *
 * When there are no messages to send, MSG_OUT should be set to MSG_NOOP,
 * in case the target decides to put us in this phase for some strange
 * reason.
 */
p_mesgout_retry:
	/* Turn on ATN for the retry */
	mvi	SCSISIGO, ATNO;
p_mesgout:
	mov	SINDEX, MSG_OUT;
	cmp	SINDEX, MSG_IDENTIFYFLAG jne p_mesgout_from_host;
	test	SCB_CONTROL,MK_MESSAGE	jnz host_message_loop;
p_mesgout_identify:
	or	SINDEX, MSG_IDENTIFYFLAG|DISCENB, SCB_LUN;
	test	SCB_CONTROL, DISCENB jnz . + 2;
	and	SINDEX, ~DISCENB;
/*
 * Send a tag message if TAG_ENB is set in the SCB control block.
 * Use SCB_NONPACKET_TAG as the tag value.
 */
p_mesgout_tag:
	test	SCB_CONTROL,TAG_ENB jz  p_mesgout_onebyte;
	mov	SCSIDAT, SINDEX;	/* Send the identify message */
	call	phase_lock;
	cmp	LASTPHASE, P_MESGOUT	jne p_mesgout_done;
	and	SCSIDAT,TAG_ENB|SCB_TAG_TYPE,SCB_CONTROL;
	call	phase_lock;
	cmp	LASTPHASE, P_MESGOUT	jne p_mesgout_done;
	mov	SCBPTR jmp p_mesgout_onebyte;
/*
 * Interrupt the driver, and allow it to handle this message
 * phase and any required retries.
 */
p_mesgout_from_host:
	cmp	SINDEX, HOST_MSG	jne p_mesgout_onebyte;
	jmp	host_message_loop;

p_mesgout_onebyte:
	mvi	CLRSINT1, CLRATNO;
	mov	SCSIDAT, SINDEX;

/*
 * If the next bus phase after ATN drops is message out, it means
 * that the target is requesting that the last message(s) be resent.
 */
	call	phase_lock;
	cmp	LASTPHASE, P_MESGOUT	je p_mesgout_retry;

p_mesgout_done:
	mvi	CLRSINT1,CLRATNO;	/* Be sure to turn ATNO off */
	mov	LAST_MSG, MSG_OUT;
	mvi	MSG_OUT, MSG_NOOP;	/* No message left */
	jmp	ITloop;

/*
 * Message in phase.  Bytes are read using Automatic PIO mode.
 */
p_mesgin:
	/* read the 1st message byte */
	mvi	ACCUM		call inb_first;

	test	A,MSG_IDENTIFYFLAG	jnz mesgin_identify;
	cmp	A,MSG_DISCONNECT	je mesgin_disconnect;
	cmp	A,MSG_SAVEDATAPOINTER	je mesgin_sdptrs;
	cmp	ALLZEROS,A		je mesgin_complete;
	cmp	A,MSG_RESTOREPOINTERS	je mesgin_rdptrs;
	cmp	A,MSG_IGN_WIDE_RESIDUE	je mesgin_ign_wide_residue;
	cmp	A,MSG_NOOP		je mesgin_done;

/*
 * Pushed message loop to allow the kernel to
 * run it's own message state engine.  To avoid an
 * extra nop instruction after signaling the kernel,
 * we perform the phase_lock before checking to see
 * if we should exit the loop and skip the phase_lock
 * in the ITloop.  Performing back to back phase_locks
 * shouldn't hurt, but why do it twice...
 */
host_message_loop:
	call	phase_lock;	/* Benign the first time through. */
	SET_SEQINTCODE(HOST_MSG_LOOP)
	cmp	RETURN_1, EXIT_MSG_LOOP	je ITloop;
	cmp	RETURN_1, CONT_MSG_LOOP_WRITE	jne . + 3;
	mov	SCSIDAT, RETURN_2;
	jmp	host_message_loop;
	/* Must be CONT_MSG_LOOP_READ */
	mov	NONE, SCSIDAT;	/* ACK Byte */
	jmp	host_message_loop;

mesgin_ign_wide_residue:
	mov	SAVED_MODE, MODE_PTR;
	SET_MODE(M_SCSI, M_SCSI)
	shr	NEGOADDR, 4, SAVED_SCSIID;
	mov	A, NEGCONOPTS;
	RESTORE_MODE(SAVED_MODE)
	test	A, WIDEXFER jz mesgin_reject;
	/* Pull the residue byte */
	mvi	REG0	call inb_next;
	cmp	REG0, 0x01 jne mesgin_reject;
	test	SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz . + 2;
	test	SCB_TASK_ATTRIBUTE, SCB_XFERLEN_ODD jnz mesgin_done;
	SET_SEQINTCODE(IGN_WIDE_RES)
	jmp	mesgin_done;

mesgin_proto_violation:
	SET_SEQINTCODE(PROTO_VIOLATION)
	jmp	mesgin_done;
mesgin_reject:
	mvi	MSG_MESSAGE_REJECT	call mk_mesg;
mesgin_done:
	mov	NONE,SCSIDAT;		/*dummy read from latch to ACK*/
	jmp	ITloop;

#define INDEX_DISC_LIST(scsiid, lun)					\
	and	A, 0xC0, scsiid;					\
	or	SCBPTR, A, lun;						\
	clr	SCBPTR[1];						\
	and	SINDEX, 0x30, scsiid;					\
	shr	SINDEX, 3;	/* Multiply by 2 */			\
	add	SINDEX, (SCB_DISCONNECTED_LISTS & 0xFF);		\
	mvi	SINDEX[1], ((SCB_DISCONNECTED_LISTS >> 8) & 0xFF)

mesgin_identify:
	/*
	 * Determine whether a target is using tagged or non-tagged
	 * transactions by first looking at the transaction stored in
	 * the per-device, disconnected array.  If there is no untagged
	 * transaction for this target, this must be a tagged transaction.
	 */
	and	SAVED_LUN, MSG_IDENTIFY_LUNMASK, A;
	INDEX_DISC_LIST(SAVED_SCSIID, SAVED_LUN);
	bmov	DINDEX, SINDEX, 2;
	bmov	REG0, SINDIR, 2;
	cmp	REG0[1], SCB_LIST_NULL je snoop_tag;
	/* Untagged.  Clear the busy table entry and setup the SCB. */
	bmov	DINDIR, ALLONES, 2;
	bmov	SCBPTR, REG0, 2;
	jmp	setup_SCB;

/*
 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message.
 * If we get one, we use the tag returned to find the proper
 * SCB.  After receiving the tag, look for the SCB at SCB locations tag and
 * tag + 256.
 */
snoop_tag:
	if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) {
		or	SEQ_FLAGS, 0x80;
	}
	mov	NONE, SCSIDAT;		/* ACK Identify MSG */
	call	phase_lock;
	if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) {
		or	SEQ_FLAGS, 0x1;
	}
	cmp	LASTPHASE, P_MESGIN	jne not_found_ITloop;
	if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) {
		or	SEQ_FLAGS, 0x2;
	}
	cmp	SCSIBUS, MSG_SIMPLE_Q_TAG jne not_found;
get_tag:
	clr	SCBPTR[1];
	mvi	SCBPTR	call inb_next;	/* tag value */
verify_scb:
	test	SCB_CONTROL,DISCONNECTED jz verify_other_scb;
	mov	A, SAVED_SCSIID;
	cmp	SCB_SCSIID, A jne verify_other_scb;
	mov	A, SAVED_LUN;
	cmp	SCB_LUN, A je setup_SCB_disconnected;
verify_other_scb:
	xor	SCBPTR[1], 1;
	test	SCBPTR[1], 0xFF jnz verify_scb;
	jmp	not_found;

/*
 * Ensure that the SCB the tag points to is for
 * an SCB transaction to the reconnecting target.
 */
setup_SCB:
	if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) {
		or	SEQ_FLAGS, 0x10;
	}
	test	SCB_CONTROL,DISCONNECTED jz not_found;
setup_SCB_disconnected:
	and	SCB_CONTROL,~DISCONNECTED;
	clr	SEQ_FLAGS;	/* make note of IDENTIFY */
	test	SCB_SGPTR, SG_LIST_NULL jnz . + 3;
	bmov	ALLOCFIFO_SCBPTR, SCBPTR, 2;
	call	allocate_fifo;
	/* See if the host wants to send a message upon reconnection */
	test	SCB_CONTROL, MK_MESSAGE jz mesgin_done;
	mvi	HOST_MSG	call mk_mesg;
	jmp	mesgin_done;

not_found:
	SET_SEQINTCODE(NO_MATCH)
	jmp	mesgin_done;

not_found_ITloop:
	SET_SEQINTCODE(NO_MATCH)
	jmp	ITloop;

/*
 * We received a "command complete" message.  Put the SCB on the complete
 * queue and trigger a completion interrupt via the idle loop.  Before doing
 * so, check to see if there is a residual or the status byte is something
 * other than STATUS_GOOD (0).  In either of these conditions, we upload the
 * SCB back to the host so it can process this information.
 */
mesgin_complete:

	/*
	 * If ATN is raised, we still want to give the target a message.
	 * Perhaps there was a parity error on this last message byte.
	 * Either way, the target should take us to message out phase
	 * and then attempt to complete the command again.  We should use a
	 * critical section here to guard against a timeout triggering
	 * for this command and setting ATN while we are still processing
	 * the completion.
	test	SCSISIGI, ATNI jnz mesgin_done;
	 */

	/*
	 * If we are identified and have successfully sent the CDB,
	 * any status will do.  Optimize this fast path.
	 */
	test	SCB_CONTROL, STATUS_RCVD jz mesgin_proto_violation;
	test	SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT jz complete_accepted;

	/*
	 * If the target never sent an identify message but instead went
	 * to mesgin to give an invalid message, let the host abort us.
	 */
	test	SEQ_FLAGS, NOT_IDENTIFIED jnz mesgin_proto_violation;

	/*
	 * If we recevied good status but never successfully sent the
	 * cdb, abort the command.
	 */
	test	SCB_SCSI_STATUS,0xff	jnz complete_accepted;
	test	SEQ_FLAGS, NO_CDB_SENT jnz mesgin_proto_violation;
complete_accepted:

	/*
	 * See if we attempted to deliver a message but the target ingnored us.
	 */
	test	SCB_CONTROL, MK_MESSAGE jz complete_nomsg;
	SET_SEQINTCODE(MKMSG_FAILED)
complete_nomsg:
	call	queue_scb_completion;
	jmp	await_busfree;

BEGIN_CRITICAL;
freeze_queue:
	/* Cancel any pending select-out. */
	test	SSTAT0, SELDO|SELINGO jnz . + 2;
	and	SCSISEQ0, ~ENSELO;
	mov	ACCUM_SAVE, A;
	clr	A;
	add	QFREEZE_COUNT, 1;
	adc	QFREEZE_COUNT[1], A;
	or	SEQ_FLAGS2, SELECTOUT_QFROZEN;
	mov	A, ACCUM_SAVE ret;
END_CRITICAL;

/*
 * Complete the current FIFO's SCB if data for this same
 * SCB is not transferring in the other FIFO.
 */
SET_SRC_MODE	M_DFF1;
SET_DST_MODE	M_DFF1;
pkt_complete_scb_if_fifos_idle:
	bmov	ARG_1, SCBPTR, 2;
	mvi	DFFSXFRCTL, CLRCHN;
	SET_MODE(M_SCSI, M_SCSI)
	bmov	SCBPTR, ARG_1, 2;