No longer clear all interrupt status when the sequencer is reset. The only

time that we really want to do this is when a bus reset causes the sequencer
to be reset and the kernel driver now handles this case.

Remove some reordering in the select2 routine that wasn't necessary.
It was an experimental fix for a race condition I fixed elsewhere, and
confused the code flow.

Don't bother looping on a parity error in the mesgout loop since we can't
see parity errors on out phases.

Clean up the mesgin_identify code.  In the old days, we "snooped" for tag
messages and used this as an indicator of whether or not the target was
using tagged transactions.  This forced the sequencer to ack the identify
before determining if a valid SCB matched the target meaning that an abort
message to handle this case might not be seen before the target entered a
data phase.  Since we can determin the "tagged-ness" of a target by looking
it up in the array of busy targets (recently introduced), we can determine
this up front simplifying the search code as well as ensuring we can follow
the SCSI specs method for rejecting a reselection.

When an SCB is placed on the free list, set its SCB_TAG to SCB_LIST_NULL.
This makes it much easier for the kernel driver to find active SCBs on the
card during error recovery.

1 files changed, 29 insertions, 40 deletions

diff --git a/sys/dev/aic7xxx/aic7xxx.seq b/sys/dev/aic7xxx/aic7xxx.seq
index d27dea0..391e13e 100644
--- a/sys/dev/aic7xxx/aic7xxx.seq
+++ b/sys/dev/aic7xxx/aic7xxx.seq
@@ -39,7 +39,7 @@
  *
  *-M************************************************************************/
 
-VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.61 1997/02/22 09:28:51 peter Exp $"
+VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.62 1997/02/25 03:02:56 gibbs Exp$"
 
 #if defined(__NetBSD__)
 #include "../../../../dev/ic/aic7xxxreg.h"
@@ -81,8 +81,6 @@ A = ACCUM
  */
 reset:
 	clr	SCSISIGO		/* De-assert BSY */
-	mvi	CLRSINT0, 0xFF		/* Clear all interrupts */
-	mvi	CLRSINT1, 0xFF		/* Clear all interrupts */
 	mvi	SCSISEQ,0x12		/* Always allow reselection 
 					 * ENRSELI|ENAUTOATNP
 					 */
@@ -283,18 +281,18 @@ select:
 	mov	WAITING_SCBH,SCB_NEXT
 select2:
 	/* Turn off the selection hardware */
-	mvi	CLRSINT1,CLRBUSFREE
 	mvi	SCSISEQ, 0x12			/* ENRSELI|ENAUTOATNP
 						 * ATN on parity errors
 						 * for "in" phases
 						 */
+	mvi	CLRSINT0,0x60			/* CLRSELDI|CLRSELDO */
+	mvi	CLRSINT1,CLRBUSFREE
 	or	SIMODE1, ENBUSFREE		/*
 						 * We aren't expecting a
 						 * bus free, so interrupt
 						 * the kernel driver if it
 						 * happens.
 						 */
-	mvi	CLRSINT0,0x60			/* CLRSELDI|CLRSELDO */
 /*
  * Initialize Ultra mode setting and clear the SCSI channel.
  */
@@ -547,13 +545,7 @@ p_mesgout_start:
  * a MESSAGE REJECT.
  */
 p_mesgout_loop:
-	/*
-	 * If there is a parity error, wait for the kernel to
-	 * see the interrupt and "update" our message response
-	 * before continuing.
-	 */
 	test	SSTAT1, REQINIT	jz p_mesgout_loop
-	test	SSTAT1, SCSIPERR jnz p_mesgout_loop
 	and	LASTPHASE, PHASE_MASK, SCSISIGI
 	cmp	LASTPHASE, P_MESGOUT jne p_mesgout_done
 /*
@@ -568,8 +560,8 @@ p_mesgout_dropatn:
 	cmp	DINDEX,1	jne p_mesgout_outb	/* last byte? */
 	mvi	CLRSINT1,CLRATNO			/* drop ATN */
 p_mesgout_outb:
-	dec	DINDEX
 	mov	SCSIDATL,SINDIR
+	dec	DINDEX
 	jmp	p_mesgout_loop
 
 p_mesgout_done:
@@ -769,23 +761,23 @@ mesgin_identify:
 	test	A,0x78	jnz rej_mesgin	/*!DiscPriv|!LUNTAR|!Reserved*/
 	and	A,0x07			/* lun in lower three bits */
 	or      SAVED_TCL,A		/* SAVED_TCL should be complete now */
-	call	inb_last		/* ACK */
-
+	mov	SAVED_TCL call index_untagged_scb
+	mov	ARG_1, SINDIR
+	cmp	ARG_1,SCB_LIST_NULL	jne use_findSCB
 /*
  * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message.
- * If we get one, we use the tag returned to switch to find the proper
+ * If we get one, we use the tag returned to find the proper
  * SCB.  With SCB paging, this requires using findSCB 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.
  */
-	mvi	ARG_1,SCB_LIST_NULL	/* Default to no-tag */
+	call    inb_last                /* ACK Identify MSG */
 snoop_tag_loop:
 	test	SSTAT1,REQINIT		jz snoop_tag_loop
 	and	LASTPHASE, PHASE_MASK, SCSISIGI
-	cmp	LASTPHASE, P_MESGIN, jne use_findSCB
-	mvi	A			call inb_first
-	cmp	A,MSG_SIMPLE_Q_TAG	jne use_findSCB
+	cmp	LASTPHASE, P_MESGIN	jne not_found
+	cmp	SCSIBUSL,MSG_SIMPLE_Q_TAG jne not_found
 get_tag:
 	or	FLAGS, TAGGED_SCB
 	mvi	ARG_1	call inb_next	/* tag value */
@@ -796,7 +788,7 @@ get_tag:
  */
 	mov	A,COMP_SCBCOUNT	
 	add	SINDEX,A,ARG_1
-	jc	send_abort_msg
+	jc	not_found
 
 /*
  * Ensure that the SCB the tag points to is for an SCB transaction
@@ -809,24 +801,28 @@ use_findSCB:
 setup_SCB:
 	and	SCB_CONTROL,0xfb	  /* clear disconnect bit in SCB */
 	or	FLAGS,IDENTIFY_SEEN	  /* make note of IDENTIFY */
-	test	SCB_CONTROL,TAG_ENB	jnz  mesgin_done /* Ack Tag */
-	jmp	ITloop
+	jmp	mesgin_done
 index_by_tag:
 	mov	SCBPTR,ARG_1
 	mov	A, SAVED_TCL
-	cmp	SCB_TCL,A		jne send_abort_msg
-	test	SCB_CONTROL,TAG_ENB	jz  send_abort_msg
-	test	SCB_CONTROL,DISCONNECTED jz send_abort_msg
+	cmp	SCB_TCL,A		jne not_found
+	test	SCB_CONTROL,TAG_ENB	jz  not_found
+	test	SCB_CONTROL,DISCONNECTED jz not_found
 	jmp	setup_SCB
 
 not_found:
 	mvi	INTSTAT, NO_MATCH
 send_abort_msg:
-	test	FLAGS, TAGGED_SCB jnz abort_tag_msg
+	test	FLAGS, TAGGED_SCB jnz send_abort_tag_msg
 	mvi	MSG_ABORT	call mk_mesg
-	jmp	ITloop
-abort_tag_msg:
+	jmp	send_abort_done
+send_abort_tag_msg:
 	mvi	MSG_ABORT_TAG	call mk_mesg	/* ABORT TAG message */
+send_abort_done:
+	/* If we don't have the tag ID yet, we're "looking ahead" at state
+	 * that hasn't been processed, so don't ack.
+	 */
+	cmp	ARG_1, SCB_LIST_NULL	je ITloop
 	jmp	mesgin_done
 
 /*
@@ -979,11 +975,10 @@ assert:
  */
 findSCB:
 	mov	SCBPTR,SINDEX			/* switch to next SCB */
-	test	SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/
-	cmp	ARG_1, SCB_LIST_NULL	jne findBySCBID
-	mov	A, SAVED_TCL
-	cmp	SCB_TCL,A	je foundSCB /* target ID/channel/lun match? */
-findSCB1:
+	mov	A, ARG_1			/* Tag passed in ARG_1 */
+	cmp	SCB_TAG,A	jne findSCB_loop
+	test	SCB_CONTROL,DISCONNECTED jnz foundSCB /*should be disconnected*/
+findSCB_loop:
 	inc	SINDEX
 	mov	A,SCBCOUNT
 	cmp	SINDEX,A	jne findSCB
@@ -994,18 +989,11 @@ findSCB1:
  */
 	test	FLAGS, PAGESCBS	jz find_error
 	mov	ALLZEROS	call	get_free_or_disc_scb
-	cmp	ARG_1, SCB_LIST_NULL jne find_dma_scb
-	mov	SAVED_TCL	call	index_untagged_scb
-	mov	ARG_1, SINDIR	/* SCBID of SCB to fetch */
-find_dma_scb:
 	mvi	DMAPARAMS, 0xd	/* HDMAEN|DIRECTION|FIFORESET */
 	mov	ARG_1	call dma_scb
 	test	SCB_CONTROL, ABORT_SCB jz return
 find_error:
 	mvi	SINDEX, SCB_LIST_NULL ret
-findBySCBID:
-	mov	A, ARG_1			/* Tag passed in ARG_1 */
-	cmp	SCB_TAG,A	jne findSCB1	/* Found it? */
 foundSCB:
 	test	SCB_CONTROL, ABORT_SCB jnz find_error
 	test	FLAGS,PAGESCBS	jz return
@@ -1145,6 +1133,7 @@ dequeue_free_scb:
 
 add_scb_to_free_list:
 	mov	SCB_NEXT, FREE_SCBH
+	mvi	SCB_TAG, SCB_LIST_NULL
 	mov	FREE_SCBH, SCBPTR ret
 
 add_scb_to_disc_list: