/*
* Adaptec U320 device driver firmware for Linux and FreeBSD.
*
- * Copyright (c) 1994-2001 Justin T. Gibbs.
+ * Copyright (c) 1994-2001, 2004 Justin T. Gibbs.
* Copyright (c) 2000-2002 Adaptec Inc.
* All rights reserved.
*
* $FreeBSD$
*/
-VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#119 $"
+VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#120 $"
PATCH_ARG_LIST = "struct ahd_softc *ahd"
PREFIX = "ahd_"
* one last time.
*/
test SSTAT0, SELDO jnz select_out;
-END_CRITICAL;
call start_selection;
idle_loop_checkbus:
-BEGIN_CRITICAL;
test SSTAT0, SELDO jnz select_out;
END_CRITICAL;
test SSTAT0, SELDI jnz select_in;
test CCSCBCTL, ARRDONE jz return;
fetch_new_scb_done:
and CCSCBCTL, ~(CCARREN|CCSCBEN);
- bmov REG0, SCBPTR, 2;
clr A;
add CMDS_PENDING, 1;
adc CMDS_PENDING[1], A;
clr SCB_FIFO_USE_COUNT;
/* Update the next SCB address to download. */
bmov NEXT_QUEUED_SCB_ADDR, SCB_NEXT_SCB_BUSADDR, 4;
+ /*
+ * NULL out the SCB links since these fields
+ * occupy the same location as SCB_NEXT_SCB_BUSADDR.
+ */
mvi SCB_NEXT[1], SCB_LIST_NULL;
mvi SCB_NEXT2[1], SCB_LIST_NULL;
/* Increment our position in the QINFIFO. */
mov NONE, SNSCB_QOFF;
+
/*
- * SCBs that want to send messages are always
- * queued independently. This ensures that they
- * are at the head of the SCB list to select out
- * to a target and we will see the MK_MESSAGE flag.
+ * Save SCBID of this SCB in REG0 since
+ * SCBPTR will be clobbered during target
+ * list updates. We also record the SCB's
+ * flags so that we can refer to them even
+ * after SCBPTR has been changed.
+ */
+ bmov REG0, SCBPTR, 2;
+ mov A, SCB_CONTROL;
+
+ /*
+ * Find the tail SCB of the execution queue
+ * for this target.
*/
- test SCB_CONTROL, MK_MESSAGE jnz first_new_target_scb;
shr SINDEX, 3, SCB_SCSIID;
and SINDEX, ~0x1;
mvi SINDEX[1], (WAITING_SCB_TAILS >> 8);
bmov DINDEX, SINDEX, 2;
bmov SCBPTR, SINDIR, 2;
+
+ /*
+ * Update the tail to point to the new SCB.
+ */
bmov DINDIR, REG0, 2;
+
+ /*
+ * If the queue was empty, queue this SCB as
+ * the first for this target.
+ */
cmp SCBPTR[1], SCB_LIST_NULL je first_new_target_scb;
+
+ /*
+ * SCBs that want to send messages must always be
+ * at the head of their per-target queue so that
+ * ATN can be asserted even if the current
+ * negotiation agreement is packetized. If the
+ * target queue is empty, the SCB can be queued
+ * immediately. If the queue is not empty, we must
+ * wait for it to empty before entering this SCB
+ * into the waiting for selection queue. Otherwise
+ * our batching and round-robin selection scheme
+ * could allow commands to be queued out of order.
+ * To simplify the implementation, we stop pulling
+ * new commands from the host until the MK_MESSAGE
+ * SCB can be queued to the waiting for selection
+ * list.
+ */
+ test A, MK_MESSAGE jz batch_scb;
+
+ /*
+ * If the last SCB is also a MK_MESSAGE SCB, then
+ * order is preserved even if we batch.
+ */
+ test SCB_CONTROL, MK_MESSAGE jz batch_scb;
+
+ /*
+ * Defer this SCB and stop fetching new SCBs until
+ * it can be queued. Since the SCB_SCSIID of the
+ * tail SCB must be the same as that of the newly
+ * queued SCB, there is no need to restore the SCBID
+ * here.
+ */
+ or SEQ_FLAGS2, PENDING_MK_MESSAGE;
+ bmov MK_MESSAGE_SCB, REG0, 2;
+ mov MK_MESSAGE_SCSIID, SCB_SCSIID ret;
+
+batch_scb:
+ /*
+ * Otherwise just update the previous tail SCB to
+ * point to the new tail.
+ */
bmov SCB_NEXT, REG0, 2 ret;
+
first_new_target_scb:
+ /*
+ * Append SCB to the tail of the waiting for
+ * selection list.
+ */
cmp WAITING_TID_HEAD[1], SCB_LIST_NULL je first_new_scb;
bmov SCBPTR, WAITING_TID_TAIL, 2;
bmov SCB_NEXT2, REG0, 2;
bmov WAITING_TID_TAIL, REG0, 2 ret;
first_new_scb:
+ /*
+ * Whole list is empty, so the head of
+ * the list must be initialized too.
+ */
bmov WAITING_TID_HEAD, REG0, 2;
bmov WAITING_TID_TAIL, REG0, 2 ret;
END_CRITICAL;
scbdma_idle:
/*
- * Give precedence to downloading new SCBs to execute
- * unless select-outs are currently frozen.
+ * Don't bother downloading new SCBs to execute
+ * if select-outs are currently frozen or we have
+ * a MK_MESSAGE SCB waiting to enter the queue.
*/
- test SEQ_FLAGS2, SELECTOUT_QFROZEN jnz . + 2;
+ test SEQ_FLAGS2, SELECTOUT_QFROZEN|PENDING_MK_MESSAGE
+ jnz scbdma_no_new_scbs;
BEGIN_CRITICAL;
test QOFF_CTLSTA, NEW_SCB_AVAIL jnz fetch_new_scb;
+scbdma_no_new_scbs:
cmp COMPLETE_DMA_SCB_HEAD[1], SCB_LIST_NULL jne dma_complete_scb;
cmp COMPLETE_SCB_HEAD[1], SCB_LIST_NULL je return;
/* FALLTHROUGH */
}
/*
- * Requeue any SCBs not sent, to the tail of the waiting Q.
+ * The whole list made it. Clear our tail pointer to indicate
+ * that the per-target selection queue is now empty.
*/
- cmp SCB_NEXT[1], SCB_LIST_NULL je select_out_list_done;
+ cmp SCB_NEXT[1], SCB_LIST_NULL je select_out_clear_tail;
/*
+ * Requeue any SCBs not sent, to the tail of the waiting Q.
* We know that neither the per-TID list nor the list of
- * TIDs is empty. Use this knowledge to our advantage.
+ * TIDs is empty. Use this knowledge to our advantage and
+ * queue the remainder to the tail of the global execution
+ * queue.
*/
bmov REG0, SCB_NEXT, 2;
+select_out_queue_remainder:
bmov SCBPTR, WAITING_TID_TAIL, 2;
bmov SCB_NEXT2, REG0, 2;
bmov WAITING_TID_TAIL, REG0, 2;
jmp select_out_inc_tid_q;
-select_out_list_done:
+select_out_clear_tail:
+ /*
+ * Queue any pending MK_MESSAGE SCB for this target now
+ * that the queue is empty.
+ */
+ test SEQ_FLAGS2, PENDING_MK_MESSAGE jz select_out_no_mk_message_scb;
+ mov A, MK_MESSAGE_SCSIID;
+ cmp SCB_SCSIID, A jne select_out_no_mk_message_scb;
+ and SEQ_FLAGS2, ~PENDING_MK_MESSAGE;
+ bmov REG0, MK_MESSAGE_SCB, 2;
+ jmp select_out_queue_remainder;
+
+select_out_no_mk_message_scb:
/*
- * The whole list made it. Just clear our TID's tail pointer
- * unless we were queued independently due to our need to
- * send a message.
+ * Clear this target's execution tail and increment the queue.
*/
- test SCB_CONTROL, MK_MESSAGE jnz select_out_inc_tid_q;
shr DINDEX, 3, SCB_SCSIID;
or DINDEX, 1; /* Want only the second byte */
mvi DINDEX[1], ((WAITING_SCB_TAILS) >> 8);
mvi WAITING_TID_TAIL[1], SCB_LIST_NULL;
bmov SCBPTR, CURRSCB, 2;
mvi CLRSINT0, CLRSELDO;
- test LQOSTAT2, LQOPHACHGOUTPKT jnz unexpected_nonpkt_phase;
- test LQOSTAT1, LQOPHACHGINPKT jnz unexpected_nonpkt_phase;
+ test LQOSTAT2, LQOPHACHGOUTPKT jnz unexpected_nonpkt_mode_cleared;
+ test LQOSTAT1, LQOPHACHGINPKT jnz unexpected_nonpkt_mode_cleared;
/*
* If this is a packetized connection, return to our
mvi DFFSXFRCTL, CLRCHN;
unexpected_nonpkt_mode_cleared:
mvi CLRSINT2, CLRNONPACKREQ;
+ if ((ahd->bugs & AHD_BUSFREEREV_BUG) != 0) {
+ /*
+ * Test to ensure that the bus has not
+ * already gone free prior to clearing
+ * any stale busfree status. This avoids
+ * a window whereby a busfree just after
+ * a selection could be missed.
+ */
+ test SCSISIGI, BSYI jz . + 2;
+ mvi CLRSINT1,CLRBUSFREE;
+ or SIMODE1, ENBUSFREE;
+ }
test SCSIPHASE, ~(MSG_IN_PHASE|MSG_OUT_PHASE) jnz illegal_phase;
SET_SEQINTCODE(ENTERING_NONPACK)
jmp ITloop;
projects / powerpc.git / blobdiff