aic7xxx.seq

linux-2.6.15.6

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

	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_EXTENDED		je mesgin_extended;
	cmp	A,MSG_MESSAGE_REJECT	je mesgin_reject;
	cmp	A,MSG_NOOP		je mesgin_done;
	cmp	A,MSG_IGN_WIDE_RESIDUE	je mesgin_wide_residue;

rej_mesgin:
/*
 * We have no idea what this message in is, so we issue a message reject
 * and hope for the best.  In any case, rejection should be a rare
 * occurrence - signal the driver when it happens.
 */
	mvi	INTSTAT,SEND_REJECT;		/* let driver know */

	mvi	MSG_MESSAGE_REJECT	call mk_mesg;

mesgin_done:
	mov	NONE,SCSIDATL;		/*dummy read from latch to ACK*/
	jmp	ITloop;


mesgin_complete:
/*
 * We got a "command complete" message, so put the SCB_TAG into the QOUTFIFO,
 * and trigger a completion interrupt.  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.  In the case of a non zero status byte, we 
 * additionally interrupt the kernel driver synchronously, allowing it to
 * decide if sense should be retrieved.  If the kernel driver wishes to request
 * sense, it will fill the kernel SCB with a request sense command and set
 * RETURN_1 to SEND_SENSE.  If RETURN_1 is set to SEND_SENSE we redownload
 * the SCB, and process it as the next command by adding it to the waiting list.
 * If the kernel driver does not wish to request sense, it need only clear
 * RETURN_1, and the command is allowed to complete normally.  We don't bother
 * to post to the QOUTFIFO in the error cases since it would require extra
 * work in the kernel driver to ensure that the entry was removed before the
 * command complete code tried processing it.
 */

/*
 * First check for residuals
 */
	test	SCB_RESID_SGCNT,0xff	jnz upload_scb;
	test	SCB_TARGET_STATUS,0xff	jz complete;	/* Good Status? */
upload_scb:
	mvi	DMAPARAMS, FIFORESET;
	mov	SCB_TAG		call dma_scb;
check_status:
	test	SCB_TARGET_STATUS,0xff	jz complete;	/* Just a residual? */
	mvi	INTSTAT,BAD_STATUS;			/* let driver know */
	nop;
	cmp	RETURN_1, SEND_SENSE	jne complete;
	/* This SCB becomes the next to execute as it will retrieve sense */
	mvi	DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
	mov	SCB_TAG		call dma_scb;
add_to_waiting_list:
	mov	SCB_NEXT,WAITING_SCBH;
	mov	WAITING_SCBH, SCBPTR;
	/*
	 * Prepare our selection hardware before the busfree so we have a
	 * high probability of winning arbitration.
	 */
	call	start_selection;
	jmp	await_busfree;

complete:
	/* If we are untagged, clear our address up in host ram */
	test	SCB_CONTROL, TAG_ENB jnz complete_post;
	mov	A, SAVED_TCL;
	mvi	UNTAGGEDSCB_OFFSET call post_byte_setup;
	mvi	SCB_LIST_NULL call post_byte;

complete_post:
	/* Post the SCB and issue an interrupt */
	if ((p->features & AHC_QUEUE_REGS) != 0) {
		mov	A, SDSCB_QOFF;
	} else {
		mov	A, QOUTPOS;
	}
	mvi	QOUTFIFO_OFFSET call post_byte_setup;
	mov	SCB_TAG call post_byte;
	if ((p->features & AHC_QUEUE_REGS) == 0) {
		inc 	QOUTPOS;
	}
	mvi	INTSTAT,CMDCMPLT;

add_to_free_list:
	call	add_scb_to_free_list;
	jmp	await_busfree;

/*
 * Is it an extended message?  Copy the message to our message buffer and
 * notify the host.  The host will tell us whether to reject this message,
 * respond to it with the message that the host placed in our message buffer,
 * or simply to do nothing.
 */
mesgin_extended:
	mvi	INTSTAT,EXTENDED_MSG;		/* let driver know */
	jmp	ITloop;

/*
 * Is it a disconnect message?  Set a flag in the SCB to remind us
 * and await the bus going free.
 */
mesgin_disconnect:
	or	SCB_CONTROL,DISCONNECTED;
	call	add_scb_to_disc_list;
	jmp	await_busfree;

/*
 * Save data pointers message:
 * Copying RAM values back to SCB, for Save Data Pointers message, but
 * only if we've actually been into a data phase to change them.  This
 * protects against bogus data in scratch ram and the residual counts
 * since they are only initialized when we go into data_in or data_out.
 */
mesgin_sdptrs:
	test	SEQ_FLAGS, DPHASE	jz mesgin_done;
	/*
	 * The SCB SGPTR becomes the next one we'll download,
	 * and the SCB DATAPTR becomes the current SHADDR.
	 * Use the residual number since STCNT is corrupted by
	 * any message transfer.
	 */
	if ((p->features & AHC_CMD_CHAN) != 0) {
		bmov    SCB_SGCOUNT, SG_COUNT, 5;
		bmov    SCB_DATAPTR, SHADDR, 4;
		bmov    SCB_DATACNT, SCB_RESID_DCNT, 3;
	} else {
		mvi	DINDEX, SCB_SGCOUNT;
		mvi	SG_COUNT	call bcopy_5;
		mvi	DINDEX, SCB_DATAPTR;
		mvi	SHADDR		call bcopy_4;
		mvi	SCB_RESID_DCNT	call	bcopy_3;
	}
	jmp	mesgin_done;

/*
 * Restore pointers message?  Data pointers are recopied from the
 * SCB anytime we enter a data phase for the first time, so all
 * we need to do is clear the DPHASE flag and let the data phase
 * code do the rest.
 */
mesgin_rdptrs:
	and	SEQ_FLAGS, ~DPHASE;		/*
						 * We'll reload them
						 * the next time through
						 * the dataphase.
						 */
	jmp	mesgin_done;

/*
 * Identify message?  For a reconnecting target, this tells us the lun
 * that the reconnection is for - find the correct SCB and switch to it,
 * clearing the "disconnected" bit so we don't "find" it by accident later.
 */
mesgin_identify:
	
	if ((p->features & AHC_WIDE) != 0) {
		and	A,0x0f;		/* lun in lower four bits */
	} else {
		and	A,0x07;		/* lun in lower three bits */
	}
	or      SAVED_TCL,A;		/* SAVED_TCL should be complete now */

	mvi     ARG_2, SCB_LIST_NULL;   /* SCBID of prev SCB in disc List */
	call	get_untagged_SCBID;
	cmp	ARG_1, SCB_LIST_NULL	je snoop_tag;
	if ((p->flags & AHC_PAGESCBS) != 0) {
		test	SEQ_FLAGS, SCBPTR_VALID	jz use_retrieveSCB;
	}
	/*
	 * If the SCB was found in the disconnected list (as is
	 * always the case in non-paging scenarios), SCBPTR is already
	 * set to the correct SCB.  So, simply setup the SCB and get
	 * on with things.
	 */
	mov	SCBPTR	call rem_scb_from_disc_list;
	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.  With SCB paging, this requires using search for both tagged
 * and non-tagged transactions since the SCB may exist in any slot.
 * If we're not using SCB paging, we can use the tag as the direct
 * index to the SCB.
 */
snoop_tag:
	mov	NONE,SCSIDATL;		/* ACK Identify MSG */
snoop_tag_loop:
	call	phase_lock;
	cmp	LASTPHASE, P_MESGIN	jne not_found;
	cmp	SCSIBUSL,MSG_SIMPLE_Q_TAG jne not_found;
get_tag:
	mvi	ARG_1	call inb_next;	/* tag value */

use_retrieveSCB:
	call	retrieveSCB;
setup_SCB:
	mov	A, SAVED_TCL;
	cmp	SCB_TCL, A	jne not_found_cleanup_scb;
	test	SCB_CONTROL,DISCONNECTED jz not_found_cleanup_scb;
	and	SCB_CONTROL,~DISCONNECTED;
	or	SEQ_FLAGS,IDENTIFY_SEEN;	  /* make note of IDENTIFY */
	/* See if the host wants to send a message upon reconnection */
	test	SCB_CONTROL, MK_MESSAGE jz mesgin_done;
	and	SCB_CONTROL, ~MK_MESSAGE;
	mvi	HOST_MSG	call mk_mesg;
	jmp	mesgin_done;

not_found_cleanup_scb:
	test	SCB_CONTROL, DISCONNECTED jz . + 3;
	call	add_scb_to_disc_list;
	jmp	not_found;
	call	add_scb_to_free_list;
not_found:
	mvi	INTSTAT, NO_MATCH;
	mvi	MSG_BUS_DEV_RESET	call mk_mesg;
	jmp	mesgin_done;

/*
 * Message reject?  Let the kernel driver handle this.  If we have an 
 * outstanding WDTR or SDTR negotiation, assume that it's a response from 
 * the target selecting 8bit or asynchronous transfer, otherwise just ignore 
 * it since we have no clue what it pertains to.
 */
mesgin_reject:
	mvi	INTSTAT, REJECT_MSG;
	jmp	mesgin_done;

/*
 * Wide Residue.  We handle the simple cases, but pass of the one hard case
 * to the kernel (when the residue byte happened to cause us to advance our
 * sg element array, so we know have to back that advance out).
 */
mesgin_wide_residue:
	mvi	ARG_1	call inb_next; /* ACK the wide_residue and get */
				       /* the size byte */
/*
 * In order for this to be reliable, we have to do all sorts of horrible
 * magic in terms of resetting the datafifo and reloading the shadow layer
 * with the correct new values (so that a subsequent save data pointers
 * message will do the right thing).  We let the kernel do that work.
 */
 	mvi	INTSTAT, WIDE_RESIDUE;
	jmp	mesgin_done;
	
/*
 * [ ADD MORE MESSAGE HANDLING HERE ]
 */

/*
 * Locking the driver out, build a one-byte message passed in SINDEX
 * if there is no active message already.  SINDEX is returned intact.
 */
mk_mesg:
	or	SCSISIGO,ATNO,LASTPHASE;/* turn on ATNO */
	mov	MSG_OUT,SINDEX ret;

/*
 * Functions to read data in Automatic PIO mode.
 *
 * According to Adaptec's documentation, an ACK is not sent on input from
 * the target until SCSIDATL is read from.  So we wait until SCSIDATL is
 * latched (the usual way), then read the data byte directly off the bus
 * using SCSIBUSL.  When we have pulled the ATN line, or we just want to
 * acknowledge the byte, then we do a dummy read from SCISDATL.  The SCSI
 * spec guarantees that the target will hold the data byte on the bus until
 * we send our ACK.
 *
 * The assumption here is that these are called in a particular sequence,
 * and that REQ is already set when inb_first is called.  inb_{first,next}
 * use the same calling convention as inb.
 */

inb_next:
	mov	NONE,SCSIDATL;		/*dummy read from latch to ACK*/
inb_next_wait:
	/*
	 * If there is a parity error, wait for the kernel to
	 * see the interrupt and prepare our message response
	 * before continuing.
	 */
	test	SSTAT1, REQINIT	jz inb_next_wait;
	test	SSTAT1, SCSIPERR jnz .;
	and	LASTPHASE, PHASE_MASK, SCSISIGI;
	cmp	LASTPHASE, P_MESGIN jne mesgin_phasemis;
inb_first:
	mov	DINDEX,SINDEX;
	mov	DINDIR,SCSIBUSL	ret;		/*read byte directly from bus*/
inb_last:
	mov	NONE,SCSIDATL ret;		/*dummy read from latch to ACK*/

	
mesgin_phasemis:
/*
 * We expected to receive another byte, but the target changed phase
 */
	mvi	INTSTAT, MSGIN_PHASEMIS;
	jmp	ITloop;

/*
 * DMA data transfer.  HADDR and HCNT must be loaded first, and
 * SINDEX should contain the value to load DFCNTRL with - 0x3d for
 * host->scsi, or 0x39 for scsi->host.  The SCSI channel is cleared
 * during initialization.
 */
if ((p->features & AHC_ULTRA2) == 0) {
dma:
	mov	DFCNTRL,SINDEX;
dma_loop:
	test	SSTAT0,DMADONE	jnz dma_dmadone;
	test	SSTAT1,PHASEMIS	jz dma_loop;	/* ie. underrun */
dma_phasemis:
	test	SSTAT0,SDONE	jnz dma_checkfifo;
	mov	SINDEX,ALLZEROS;		/* Notify caller of phasemiss */

/*
 * We will be "done" DMAing when the transfer count goes to zero, or
 * the target changes the phase (in light of this, it makes sense that
 * the DMA circuitry doesn't ACK when PHASEMIS is active).  If we are
 * doing a SCSI->Host transfer, the data FIFO should be flushed auto-
 * magically on STCNT=0 or a phase change, so just wait for FIFO empty
 * status.
 */
dma_checkfifo:
	test	DFCNTRL,DIRECTION	jnz dma_fifoempty;
dma_fifoflush:
	test	DFSTATUS,FIFOEMP	jz dma_fifoflush;

dma_fifoempty:
	/* Don't clobber an inprogress host data transfer */
	test	DFSTATUS, MREQPEND	jnz dma_fifoempty;
/*
 * Now shut the DMA enables off and make sure that the DMA enables are 
 * actually off first lest we get an ILLSADDR.
 */
dma_dmadone:
	cmp	LASTPHASE, P_COMMAND	je dma_await_nreq;
	test	SCSIRATE, 0x0f	jnz dma_shutdown;
dma_await_nreq:
	test	SCSISIGI, REQI	jz dma_shutdown;
	test	SSTAT1, (PHASEMIS|REQINIT)	jz dma_await_nreq;
dma_shutdown:
	and	DFCNTRL, ~(SCSIEN|SDMAEN|HDMAEN);
dma_halt:
	/*
	 * Some revisions of the aic7880 have a problem where, if the
	 * data fifo is full, but the PCI input latch is not empty, 
	 * HDMAEN cannot be cleared.  The fix used here is to attempt
	 * to drain the data fifo until there is space for the input
	 * latch to drain and HDMAEN de-asserts.
	 */
	if ((p->bugs & AHC_BUG_PCI_2_1_RETRY) != 0) {
		mov	NONE, DFDAT;
	}
	test	DFCNTRL, (SCSIEN|SDMAEN|HDMAEN) jnz dma_halt;
}
return:
	ret;

/*
 * Assert that if we've been reselected, then we've seen an IDENTIFY
 * message.
 */
assert:
	test	SEQ_FLAGS,IDENTIFY_SEEN	jnz return;	/* seen IDENTIFY? */

	mvi	INTSTAT,NO_IDENT 	ret;	/* no - tell the kernel */

/*
 * Locate a disconnected SCB either by SAVED_TCL (ARG_1 is SCB_LIST_NULL)
 * or by the SCBID ARG_1.  The search begins at the SCB index passed in
 * via SINDEX which is an SCB that must be on the disconnected list.  If