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1/*2 * Adaptec 274x/284x/294x device driver firmware for Linux and FreeBSD.3 *4 * Copyright (c) 1994-2001 Justin T. Gibbs.5 * Copyright (c) 2000-2001 Adaptec Inc.6 * All rights reserved.7 *8 * Redistribution and use in source and binary forms, with or without9 * modification, are permitted provided that the following conditions10 * are met:11 * 1. Redistributions of source code must retain the above copyright12 *    notice, this list of conditions, and the following disclaimer,13 *    without modification.14 * 2. Redistributions in binary form must reproduce at minimum a disclaimer15 *    substantially similar to the "NO WARRANTY" disclaimer below16 *    ("Disclaimer") and any redistribution must be conditioned upon17 *    including a substantially similar Disclaimer requirement for further18 *    binary redistribution.19 * 3. Neither the names of the above-listed copyright holders nor the names20 *    of any contributors may be used to endorse or promote products derived21 *    from this software without specific prior written permission.22 *23 * Alternatively, this software may be distributed under the terms of the24 * GNU General Public License ("GPL") version 2 as published by the Free25 * Software Foundation.26 *27 * NO WARRANTY28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT32 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,36 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING37 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE38 * POSSIBILITY OF SUCH DAMAGES.39 *40 * $FreeBSD$41 */42 43VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic7xxx.seq#58 $"44PATCH_ARG_LIST = "struct ahc_softc *ahc"45PREFIX = "ahc_"46 47#include "aic7xxx.reg"48#include "scsi_message.h"49 50/*51 * A few words on the waiting SCB list:52 * After starting the selection hardware, we check for reconnecting targets53 * as well as for our selection to complete just in case the reselection wins54 * bus arbitration.  The problem with this is that we must keep track of the55 * SCB that we've already pulled from the QINFIFO and started the selection56 * on just in case the reselection wins so that we can retry the selection at57 * a later time.  This problem cannot be resolved by holding a single entry58 * in scratch ram since a reconnecting target can request sense and this will59 * create yet another SCB waiting for selection.  The solution used here is to 60 * use byte 27 of the SCB as a pseudo-next pointer and to thread a list61 * of SCBs that are awaiting selection.  Since 0-0xfe are valid SCB indexes, 62 * SCB_LIST_NULL is 0xff which is out of range.  An entry is also added to63 * this list every time a request sense occurs or after completing a non-tagged64 * command for which a second SCB has been queued.  The sequencer will65 * automatically consume the entries.66 */67 68bus_free_sel:69	/*70	 * Turn off the selection hardware.  We need to reset the71	 * selection request in order to perform a new selection.72	 */73	and	SCSISEQ, TEMODE|ENSELI|ENRSELI|ENAUTOATNP;74	and	SIMODE1, ~ENBUSFREE;75poll_for_work:76	call	clear_target_state;77	and	SXFRCTL0, ~SPIOEN;78	if ((ahc->features & AHC_ULTRA2) != 0) {79		clr	SCSIBUSL;80	}81	test	SCSISEQ, ENSELO	jnz poll_for_selection;82	if ((ahc->features & AHC_TWIN) != 0) {83		xor	SBLKCTL,SELBUSB;	/* Toggle to the other bus */84		test	SCSISEQ, ENSELO		jnz poll_for_selection;85	}86	cmp	WAITING_SCBH,SCB_LIST_NULL jne start_waiting;87poll_for_work_loop:88	if ((ahc->features & AHC_TWIN) != 0) {89		xor	SBLKCTL,SELBUSB;	/* Toggle to the other bus */90	}91	test	SSTAT0, SELDO|SELDI	jnz selection;92test_queue:93	/* Has the driver posted any work for us? */94BEGIN_CRITICAL;95	if ((ahc->features & AHC_QUEUE_REGS) != 0) {96		test	QOFF_CTLSTA, SCB_AVAIL jz poll_for_work_loop;97	} else {98		mov	A, QINPOS;99		cmp	KERNEL_QINPOS, A je poll_for_work_loop;100	}101	mov	ARG_1, NEXT_QUEUED_SCB;102 103	/*104	 * We have at least one queued SCB now and we don't have any 105	 * SCBs in the list of SCBs awaiting selection.  Allocate a106	 * card SCB for the host's SCB and get to work on it.107	 */108	if ((ahc->flags & AHC_PAGESCBS) != 0) {109		mov	ALLZEROS	call	get_free_or_disc_scb;110	} else {111		/* In the non-paging case, the SCBID == hardware SCB index */112		mov	SCBPTR, ARG_1;113	}114	or	SEQ_FLAGS2, SCB_DMA;115END_CRITICAL;116dma_queued_scb:117	/*118	 * DMA the SCB from host ram into the current SCB location.119	 */120	mvi	DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;121	mov	ARG_1	call dma_scb;122	/*123	 * Check one last time to see if this SCB was canceled124	 * before we completed the DMA operation.  If it was,125	 * the QINFIFO next pointer will not match our saved126	 * value.127	 */128	mov	A, ARG_1;129BEGIN_CRITICAL;130	cmp	NEXT_QUEUED_SCB, A jne abort_qinscb;131	if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {132		cmp	SCB_TAG, A je . + 2;133		mvi	SCB_MISMATCH call set_seqint;134	}135	mov	NEXT_QUEUED_SCB, SCB_NEXT;136	mov	SCB_NEXT,WAITING_SCBH;137	mov	WAITING_SCBH, SCBPTR;138	if ((ahc->features & AHC_QUEUE_REGS) != 0) {139		mov	NONE, SNSCB_QOFF;140	} else {141		inc	QINPOS;142	}143	and	SEQ_FLAGS2, ~SCB_DMA;144END_CRITICAL;145start_waiting:146	/*147	 * Start the first entry on the waiting SCB list.148	 */149	mov	SCBPTR, WAITING_SCBH;150	call	start_selection;151 152poll_for_selection:153	/*154	 * Twin channel devices cannot handle things like SELTO155	 * interrupts on the "background" channel.  So, while156	 * selecting, keep polling the current channel until157	 * either a selection or reselection occurs.158	 */159	test	SSTAT0, SELDO|SELDI	jz poll_for_selection;160 161selection:162	/*163	 * We aren't expecting a bus free, so interrupt164	 * the kernel driver if it happens.165	 */166	mvi	CLRSINT1,CLRBUSFREE;167	if ((ahc->features & AHC_DT) == 0) {168		or	SIMODE1, ENBUSFREE;169	}170 171	/*172	 * Guard against a bus free after (re)selection173	 * but prior to enabling the busfree interrupt.  SELDI174	 * and SELDO will be cleared in that case.175	 */176	test	SSTAT0, SELDI|SELDO	jz bus_free_sel;177	test	SSTAT0,SELDO	jnz select_out;178select_in:179	if ((ahc->flags & AHC_TARGETROLE) != 0) {180		if ((ahc->flags & AHC_INITIATORROLE) != 0) {181			test	SSTAT0, TARGET	jz initiator_reselect;182		}183		mvi	CLRSINT0, CLRSELDI;184 185		/*186		 * We've just been selected.  Assert BSY and187		 * setup the phase for receiving messages188		 * from the target.189		 */190		mvi	SCSISIGO, P_MESGOUT|BSYO;191 192		/*193		 * Setup the DMA for sending the identify and194		 * command information.195		 */196		mvi	SEQ_FLAGS, CMDPHASE_PENDING;197 198		mov     A, TQINPOS;199		if ((ahc->features & AHC_CMD_CHAN) != 0) {200			mvi	DINDEX, CCHADDR;201			mvi	SHARED_DATA_ADDR call set_32byte_addr;202			mvi	CCSCBCTL, CCSCBRESET;203		} else {204			mvi	DINDEX, HADDR;205			mvi	SHARED_DATA_ADDR call set_32byte_addr;206			mvi	DFCNTRL, FIFORESET;207		}208 209		/* Initiator that selected us */210		and	SAVED_SCSIID, SELID_MASK, SELID;211		/* The Target ID we were selected at */212		if ((ahc->features & AHC_MULTI_TID) != 0) {213			and	A, OID, TARGIDIN;214		} else if ((ahc->features & AHC_ULTRA2) != 0) {215			and	A, OID, SCSIID_ULTRA2;216		} else {217			and	A, OID, SCSIID;218		}219		or	SAVED_SCSIID, A;220		if ((ahc->features & AHC_TWIN) != 0) {221			test 	SBLKCTL, SELBUSB jz . + 2;222			or	SAVED_SCSIID, TWIN_CHNLB;223		}224		if ((ahc->features & AHC_CMD_CHAN) != 0) {225			mov	CCSCBRAM, SAVED_SCSIID;226		} else {227			mov	DFDAT, SAVED_SCSIID;228		}229 230		/*231		 * If ATN isn't asserted, the target isn't interested232		 * in talking to us.  Go directly to bus free.233		 * XXX SCSI-1 may require us to assume lun 0 if234		 * ATN is false.235		 */236		test	SCSISIGI, ATNI	jz	target_busfree;237 238		/*239		 * Watch ATN closely now as we pull in messages from the240		 * initiator.  We follow the guidlines from section 6.5241		 * of the SCSI-2 spec for what messages are allowed when.242		 */243		call	target_inb;244 245		/*246		 * Our first message must be one of IDENTIFY, ABORT, or247		 * BUS_DEVICE_RESET.248		 */249		test	DINDEX, MSG_IDENTIFYFLAG jz host_target_message_loop;250		/* Store for host */251		if ((ahc->features & AHC_CMD_CHAN) != 0) {252			mov	CCSCBRAM, DINDEX;253		} else {254			mov	DFDAT, DINDEX;255		}256		and	SAVED_LUN, MSG_IDENTIFY_LUNMASK, DINDEX;257 258		/* Remember for disconnection decision */259		test	DINDEX, MSG_IDENTIFY_DISCFLAG jnz . + 2;260		/* XXX Honor per target settings too */261		or	SEQ_FLAGS, NO_DISCONNECT;262 263		test	SCSISIGI, ATNI	jz	ident_messages_done;264		call	target_inb;265		/*266		 * If this is a tagged request, the tagged message must267		 * immediately follow the identify.  We test for a valid268		 * tag message by seeing if it is >= MSG_SIMPLE_Q_TAG and269		 * < MSG_IGN_WIDE_RESIDUE.270		 */271		add	A, -MSG_SIMPLE_Q_TAG, DINDEX;272		jnc	ident_messages_done_msg_pending;273		add	A, -MSG_IGN_WIDE_RESIDUE, DINDEX;274		jc	ident_messages_done_msg_pending;275 276		/* Store for host */277		if ((ahc->features & AHC_CMD_CHAN) != 0) {278			mov	CCSCBRAM, DINDEX;279		} else {280			mov	DFDAT, DINDEX;281		}282		283		/*284		 * If the initiator doesn't feel like providing a tag number,285		 * we've got a failed selection and must transition to bus286		 * free.287		 */288		test	SCSISIGI, ATNI	jz	target_busfree;289 290		/*291		 * Store the tag for the host.292		 */293		call	target_inb;294		if ((ahc->features & AHC_CMD_CHAN) != 0) {295			mov	CCSCBRAM, DINDEX;296		} else {297			mov	DFDAT, DINDEX;298		}299		mov	INITIATOR_TAG, DINDEX;300		or	SEQ_FLAGS, TARGET_CMD_IS_TAGGED;301 302ident_messages_done:303		/* Terminate the ident list */304		if ((ahc->features & AHC_CMD_CHAN) != 0) {305			mvi	CCSCBRAM, SCB_LIST_NULL;306		} else {307			mvi	DFDAT, SCB_LIST_NULL;308		}309		or	SEQ_FLAGS, TARG_CMD_PENDING;310		test	SEQ_FLAGS2, TARGET_MSG_PENDING311			jnz target_mesgout_pending;312		test	SCSISIGI, ATNI jnz target_mesgout_continue;313		jmp	target_ITloop;314 315 316ident_messages_done_msg_pending:317		or	SEQ_FLAGS2, TARGET_MSG_PENDING;318		jmp	ident_messages_done;319 320		/*321		 * Pushed message loop to allow the kernel to322		 * run it's own target mode message state engine.323		 */324host_target_message_loop:325		mvi	HOST_MSG_LOOP call set_seqint;326		cmp	RETURN_1, EXIT_MSG_LOOP	je target_ITloop;327		test	SSTAT0, SPIORDY jz .;328		jmp	host_target_message_loop;329	}330 331if ((ahc->flags & AHC_INITIATORROLE) != 0) {332/*333 * Reselection has been initiated by a target. Make a note that we've been334 * reselected, but haven't seen an IDENTIFY message from the target yet.335 */336initiator_reselect:337	/* XXX test for and handle ONE BIT condition */338	or	SXFRCTL0, SPIOEN|CLRSTCNT|CLRCHN;339	and	SAVED_SCSIID, SELID_MASK, SELID;340	if ((ahc->features & AHC_ULTRA2) != 0) {341		and	A, OID, SCSIID_ULTRA2;342	} else {343		and	A, OID, SCSIID;344	}345	or	SAVED_SCSIID, A;346	if ((ahc->features & AHC_TWIN) != 0) {347		test	SBLKCTL, SELBUSB	jz . + 2;348		or	SAVED_SCSIID, TWIN_CHNLB;349	}350	mvi	CLRSINT0, CLRSELDI;351	jmp	ITloop;352}353 354abort_qinscb:355	call	add_scb_to_free_list;356	jmp	poll_for_work_loop;357 358start_selection:359	/*360	 * If bus reset interrupts have been disabled (from a previous361	 * reset), re-enable them now.  Resets are only of interest362	 * when we have outstanding transactions, so we can safely363	 * defer re-enabling the interrupt until, as an initiator,364	 * we start sending out transactions again.365	 */366	test	SIMODE1, ENSCSIRST	jnz . + 3;367	mvi	CLRSINT1, CLRSCSIRSTI;368	or	SIMODE1, ENSCSIRST;369	if ((ahc->features & AHC_TWIN) != 0) {370		and	SINDEX,~SELBUSB,SBLKCTL;/* Clear channel select bit */371		test	SCB_SCSIID, TWIN_CHNLB jz . + 2;372		or	SINDEX, SELBUSB;373		mov	SBLKCTL,SINDEX;		/* select channel */374	}375initialize_scsiid:376	if ((ahc->features & AHC_ULTRA2) != 0) {377		mov	SCSIID_ULTRA2, SCB_SCSIID;378	} else if ((ahc->features & AHC_TWIN) != 0) {379		and	SCSIID, TWIN_TID|OID, SCB_SCSIID;380	} else {381		mov	SCSIID, SCB_SCSIID;382	}383	if ((ahc->flags & AHC_TARGETROLE) != 0) {384		mov	SINDEX, SCSISEQ_TEMPLATE;385		test	SCB_CONTROL, TARGET_SCB jz . + 2;386		or	SINDEX, TEMODE;387		mov	SCSISEQ, SINDEX ret;388	} else {389		mov	SCSISEQ, SCSISEQ_TEMPLATE ret;390	}391 392/*393 * Initialize transfer settings with SCB provided settings.394 */395set_transfer_settings:396	if ((ahc->features & AHC_ULTRA) != 0) {397		test	SCB_CONTROL, ULTRAENB jz . + 2;398		or	SXFRCTL0, FAST20;399	} 400	/*401	 * Initialize SCSIRATE with the appropriate value for this target.402	 */403	if ((ahc->features & AHC_ULTRA2) != 0) {404		bmov	SCSIRATE, SCB_SCSIRATE, 2 ret;405	} else {406		mov	SCSIRATE, SCB_SCSIRATE ret;407	}408 409if ((ahc->flags & AHC_TARGETROLE) != 0) {410/*411 * We carefully toggle SPIOEN to allow us to return the 412 * message byte we receive so it can be checked prior to413 * driving REQ on the bus for the next byte.414 */415target_inb:416	/*417	 * Drive REQ on the bus by enabling SCSI PIO.418	 */419	or	SXFRCTL0, SPIOEN;420	/* Wait for the byte */421	test	SSTAT0, SPIORDY jz .;422	/* Prevent our read from triggering another REQ */423	and	SXFRCTL0, ~SPIOEN;424	/* Save latched contents */425	mov	DINDEX, SCSIDATL ret;426}427 428/*429 * After the selection, remove this SCB from the "waiting SCB"430 * list.  This is achieved by simply moving our "next" pointer into431 * WAITING_SCBH.  Our next pointer will be set to null the next time this432 * SCB is used, so don't bother with it now.433 */434select_out:435	/* Turn off the selection hardware */436	and	SCSISEQ, TEMODE|ENSELI|ENRSELI|ENAUTOATNP, SCSISEQ;437	mov	SCBPTR, WAITING_SCBH;438	mov	WAITING_SCBH,SCB_NEXT;439	mov	SAVED_SCSIID, SCB_SCSIID;440	and	SAVED_LUN, LID, SCB_LUN;441	call	set_transfer_settings;442	if ((ahc->flags & AHC_TARGETROLE) != 0) {443		test	SSTAT0, TARGET	jz initiator_select;444 445		or	SXFRCTL0, CLRSTCNT|CLRCHN;446 447		/*448		 * Put tag in connonical location since not449		 * all connections have an SCB.450		 */451		mov	INITIATOR_TAG, SCB_TARGET_ITAG;452 453		/*454		 * We've just re-selected an initiator.455		 * Assert BSY and setup the phase for456		 * sending our identify messages.457		 */458		mvi	P_MESGIN|BSYO call change_phase;459		mvi	CLRSINT0, CLRSELDO;460 461		/*462		 * Start out with a simple identify message.463		 */464		or	SAVED_LUN, MSG_IDENTIFYFLAG call target_outb;465 466		/*467		 * If we are the result of a tagged command, send468		 * a simple Q tag and the tag id.469		 */470		test	SCB_CONTROL, TAG_ENB	jz . + 3;471		mvi	MSG_SIMPLE_Q_TAG call target_outb;472		mov	SCB_TARGET_ITAG call target_outb;473target_synccmd:474		/*475		 * Now determine what phases the host wants us476		 * to go through.477		 */478		mov	SEQ_FLAGS, SCB_TARGET_PHASES;479		480		test	SCB_CONTROL, MK_MESSAGE	jz target_ITloop;481		mvi	P_MESGIN|BSYO call change_phase;482		jmp	host_target_message_loop;483target_ITloop:484		/*485		 * Start honoring ATN signals now that486		 * we properly identified ourselves.487		 */488		test	SCSISIGI, ATNI			jnz target_mesgout;489		test	SEQ_FLAGS, CMDPHASE_PENDING	jnz target_cmdphase;490		test	SEQ_FLAGS, DPHASE_PENDING	jnz target_dphase;491		test	SEQ_FLAGS, SPHASE_PENDING	jnz target_sphase;492 493		/*494		 * No more work to do.  Either disconnect or not depending495		 * on the state of NO_DISCONNECT.496		 */497		test	SEQ_FLAGS, NO_DISCONNECT jz target_disconnect; 498		mvi	TARG_IMMEDIATE_SCB, SCB_LIST_NULL;499		call	complete_target_cmd;500		if ((ahc->flags & AHC_PAGESCBS) != 0) {501			mov	ALLZEROS	call	get_free_or_disc_scb;502		}503		cmp	TARG_IMMEDIATE_SCB, SCB_LIST_NULL je .;504		mvi	DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;505		mov	TARG_IMMEDIATE_SCB call dma_scb;506		call	set_transfer_settings;507		or	SXFRCTL0, CLRSTCNT|CLRCHN;508		jmp	target_synccmd;509 510target_mesgout:511		mvi	SCSISIGO, P_MESGOUT|BSYO;512target_mesgout_continue:513		call	target_inb;514target_mesgout_pending:515		and	SEQ_FLAGS2, ~TARGET_MSG_PENDING;516		/* Local Processing goes here... */517		jmp	host_target_message_loop;518		519target_disconnect:520		mvi	P_MESGIN|BSYO call change_phase;521		test	SEQ_FLAGS, DPHASE	jz . + 2;522		mvi	MSG_SAVEDATAPOINTER call target_outb;523		mvi	MSG_DISCONNECT call target_outb;524 525target_busfree_wait:526		/* Wait for preceding I/O session to complete. */527		test	SCSISIGI, ACKI jnz .;528target_busfree:529		and	SIMODE1, ~ENBUSFREE;530		if ((ahc->features & AHC_ULTRA2) != 0) {531			clr	SCSIBUSL;532		}533		clr	SCSISIGO;534		mvi	LASTPHASE, P_BUSFREE;535		call	complete_target_cmd;536		jmp	poll_for_work;537 538target_cmdphase:539		/*540		 * The target has dropped ATN (doesn't want to abort or BDR)541		 * and we believe this selection to be valid.  If the ring542		 * buffer for new commands is full, return busy or queue full.543		 */544		if ((ahc->features & AHC_HS_MAILBOX) != 0) {545			and	A, HOST_TQINPOS, HS_MAILBOX;546		} else {547			mov	A, KERNEL_TQINPOS;548		}549		cmp	TQINPOS, A jne tqinfifo_has_space;550		mvi	P_STATUS|BSYO call change_phase;551		test	SEQ_FLAGS, TARGET_CMD_IS_TAGGED jz . + 3;552		mvi	STATUS_QUEUE_FULL call target_outb;553		jmp	target_busfree_wait;554		mvi	STATUS_BUSY call target_outb;555		jmp	target_busfree_wait;556tqinfifo_has_space:	557		mvi	P_COMMAND|BSYO call change_phase;558		call	target_inb;559		mov	A, DINDEX;560		/* Store for host */561		if ((ahc->features & AHC_CMD_CHAN) != 0) {562			mov	CCSCBRAM, A;563		} else {564			mov	DFDAT, A;565		}566 567		/*568		 * Determine the number of bytes to read569		 * based on the command group code via table lookup.570		 * We reuse the first 8 bytes of the TARG_SCSIRATE571		 * BIOS array for this table. Count is one less than572		 * the total for the command since we've already fetched573		 * the first byte.574		 */575		shr	A, CMD_GROUP_CODE_SHIFT;576		add	SINDEX, CMDSIZE_TABLE, A;577		mov	A, SINDIR;578 579		test	A, 0xFF jz command_phase_done;580		or	SXFRCTL0, SPIOEN;581command_loop:582		test	SSTAT0, SPIORDY jz .;583		cmp	A, 1 jne . + 2;584		and	SXFRCTL0, ~SPIOEN;	/* Last Byte */585		if ((ahc->features & AHC_CMD_CHAN) != 0) {586			mov	CCSCBRAM, SCSIDATL;587		} else {588			mov	DFDAT, SCSIDATL;589		}590		dec	A;591		test	A, 0xFF jnz command_loop;592 593command_phase_done:594		and	SEQ_FLAGS, ~CMDPHASE_PENDING;595		jmp	target_ITloop;596 597target_dphase:598		/*599		 * Data phases on the bus are from the600		 * perspective of the initiator.  The dma601		 * code looks at LASTPHASE to determine the602		 * data direction of the DMA.  Toggle it for603		 * target transfers.604		 */605		xor	LASTPHASE, IOI, SCB_TARGET_DATA_DIR;606		or	SCB_TARGET_DATA_DIR, BSYO call change_phase;607		jmp	p_data;608 609target_sphase:610		mvi	P_STATUS|BSYO call change_phase;611		mvi	LASTPHASE, P_STATUS;612		mov	SCB_SCSI_STATUS call target_outb;613		/* XXX Watch for ATN or parity errors??? */614		mvi	SCSISIGO, P_MESGIN|BSYO;615		/* MSG_CMDCMPLT is 0, but we can't do an immediate of 0 */616		mov	ALLZEROS call target_outb;617		jmp	target_busfree_wait;618	619complete_target_cmd:620		test	SEQ_FLAGS, TARG_CMD_PENDING	jnz . + 2;621		mov	SCB_TAG jmp complete_post;622		if ((ahc->features & AHC_CMD_CHAN) != 0) {623			/* Set the valid byte */624			mvi	CCSCBADDR, 24;625			mov	CCSCBRAM, ALLONES;626			mvi	CCHCNT, 28;627			or	CCSCBCTL, CCSCBEN|CCSCBRESET;628			test	CCSCBCTL, CCSCBDONE jz .;629			clr	CCSCBCTL;630		} else {631			/* Set the valid byte */632			or	DFCNTRL, FIFORESET;633			mvi	DFWADDR, 3; /* Third 64bit word or byte 24 */634			mov	DFDAT, ALLONES;635			mvi	28	call set_hcnt;636			or	DFCNTRL, HDMAEN|FIFOFLUSH;637			call	dma_finish;638		}639		inc	TQINPOS;640		mvi	INTSTAT,CMDCMPLT ret;641	}642 643if ((ahc->flags & AHC_INITIATORROLE) != 0) {644initiator_select:645	or	SXFRCTL0, SPIOEN|CLRSTCNT|CLRCHN;646	/*647	 * As soon as we get a successful selection, the target648	 * should go into the message out phase since we have ATN649	 * asserted.650	 */651	mvi	MSG_OUT, MSG_IDENTIFYFLAG;652	mvi	SEQ_FLAGS, NO_CDB_SENT;653	mvi	CLRSINT0, CLRSELDO;654 655	/*656	 * Main loop for information transfer phases.  Wait for the657	 * target to assert REQ before checking MSG, C/D and I/O for658	 * the bus phase.659	 */660mesgin_phasemis:661ITloop:662	call	phase_lock;663 664	mov	A, LASTPHASE;665 666	test	A, ~P_DATAIN	jz p_data;667	cmp	A,P_COMMAND	je p_command;668	cmp	A,P_MESGOUT	je p_mesgout;669	cmp	A,P_STATUS	je p_status;670	cmp	A,P_MESGIN	je p_mesgin;671 672	mvi	BAD_PHASE call set_seqint;673	jmp	ITloop;			/* Try reading the bus again. */674 675await_busfree:676	and	SIMODE1, ~ENBUSFREE;677	mov	NONE, SCSIDATL;		/* Ack the last byte */678	if ((ahc->features & AHC_ULTRA2) != 0) {679		clr	SCSIBUSL;	/* Prevent bit leakage durint SELTO */680	}681	and	SXFRCTL0, ~SPIOEN;682	mvi	SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT;683	test	SSTAT1,REQINIT|BUSFREE	jz .;684	test	SSTAT1, BUSFREE jnz poll_for_work;685	mvi	MISSED_BUSFREE call set_seqint;686}687	688clear_target_state:689	/*690	 * We assume that the kernel driver may reset us691	 * at any time, even in the middle of a DMA, so692	 * clear DFCNTRL too.693	 */694	clr	DFCNTRL;695	or	SXFRCTL0, CLRSTCNT|CLRCHN;696 697	/*698	 * We don't know the target we will connect to,699	 * so default to narrow transfers to avoid700	 * parity problems.701	 */702	if ((ahc->features & AHC_ULTRA2) != 0) {703		bmov	SCSIRATE, ALLZEROS, 2;704	} else {705		clr	SCSIRATE;706		if ((ahc->features & AHC_ULTRA) != 0) {707			and	SXFRCTL0, ~(FAST20);708		}709	}710	mvi	LASTPHASE, P_BUSFREE;711	/* clear target specific flags */712	mvi	SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT ret;713 714sg_advance:715	clr	A;			/* add sizeof(struct scatter) */716	add	SCB_RESIDUAL_SGPTR[0],SG_SIZEOF;717	adc	SCB_RESIDUAL_SGPTR[1],A;718	adc	SCB_RESIDUAL_SGPTR[2],A;719	adc	SCB_RESIDUAL_SGPTR[3],A ret;720 721if ((ahc->features & AHC_CMD_CHAN) != 0) {722disable_ccsgen:723	test	CCSGCTL, CCSGEN jz return;724	test	CCSGCTL, CCSGDONE jz .;725disable_ccsgen_fetch_done:726	clr	CCSGCTL;727	test	CCSGCTL, CCSGEN jnz .;728	ret;729idle_loop:730	/*731	 * Do we need any more segments for this transfer?732	 */733	test	SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jnz return;734 735	/* Did we just finish fetching segs? */736	cmp	CCSGCTL, CCSGEN|CCSGDONE je idle_sgfetch_complete;737 738	/* Are we actively fetching segments? */739	test	CCSGCTL, CCSGEN jnz return;740 741	/*742	 * Do we have any prefetch left???743	 */744	cmp	CCSGADDR, SG_PREFETCH_CNT jne idle_sg_avail;745 746	/*747	 * Need to fetch segments, but we can only do that748	 * if the command channel is completely idle.  Make749	 * sure we don't have an SCB prefetch going on.750	 */751	test	CCSCBCTL, CCSCBEN jnz return;752 753	/*754	 * We fetch a "cacheline aligned" and sized amount of data755	 * so we don't end up referencing a non-existent page.756	 * Cacheline aligned is in quotes because the kernel will757	 * set the prefetch amount to a reasonable level if the758	 * cacheline size is unknown.759	 */760	mvi	CCHCNT, SG_PREFETCH_CNT;761	and	CCHADDR[0], SG_PREFETCH_ALIGN_MASK, SCB_RESIDUAL_SGPTR;762	bmov	CCHADDR[1], SCB_RESIDUAL_SGPTR[1], 3;763	mvi	CCSGCTL, CCSGEN|CCSGRESET ret;764idle_sgfetch_complete:765	call	disable_ccsgen_fetch_done;766	and	CCSGADDR, SG_PREFETCH_ADDR_MASK, SCB_RESIDUAL_SGPTR;767idle_sg_avail:768	if ((ahc->features & AHC_ULTRA2) != 0) {769		/* Does the hardware have space for another SG entry? */770		test	DFSTATUS, PRELOAD_AVAIL jz return;771		bmov 	HADDR, CCSGRAM, 7;772		bmov	SCB_RESIDUAL_DATACNT[3], CCSGRAM, 1;773		if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {774			mov	SCB_RESIDUAL_DATACNT[3] call set_hhaddr;775		}776		call	sg_advance;777		mov	SINDEX, SCB_RESIDUAL_SGPTR[0];778		test	SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz . + 2;779		or	SINDEX, LAST_SEG;780		mov	SG_CACHE_PRE, SINDEX;781		/* Load the segment */782		or	DFCNTRL, PRELOADEN;783	}784	ret;785}786 787if ((ahc->bugs & AHC_PCI_MWI_BUG) != 0 && ahc->pci_cachesize != 0) {788/*789 * Calculate the trailing portion of this S/G segment that cannot790 * be transferred using memory write and invalidate PCI transactions.  791 * XXX Can we optimize this for PCI writes only???792 */793calc_mwi_residual:794	/*795	 * If the ending address is on a cacheline boundary,796	 * there is no need for an extra segment.797	 */798	mov	A, HCNT[0];799	add	A, A, HADDR[0];800	and	A, CACHESIZE_MASK;801	test	A, 0xFF jz return;802 803	/*804	 * If the transfer is less than a cachline,805	 * there is no need for an extra segment.806	 */807	test	HCNT[1], 0xFF	jnz calc_mwi_residual_final;808	test	HCNT[2], 0xFF	jnz calc_mwi_residual_final;809	add	NONE, INVERTED_CACHESIZE_MASK, HCNT[0];810	jnc	return;811 812calc_mwi_residual_final:813	mov	MWI_RESIDUAL, A;814	not	A;815	inc	A;816	add	HCNT[0], A;817	adc	HCNT[1], -1;818	adc	HCNT[2], -1 ret;819}820 821p_data:822	test	SEQ_FLAGS,NOT_IDENTIFIED|NO_CDB_SENT jz p_data_allowed;823	mvi	PROTO_VIOLATION call set_seqint;824p_data_allowed:825	if ((ahc->features & AHC_ULTRA2) != 0) {826		mvi	DMAPARAMS, PRELOADEN|SCSIEN|HDMAEN;827	} else {828		mvi	DMAPARAMS, WIDEODD|SCSIEN|SDMAEN|HDMAEN|FIFORESET;829	}830	test	LASTPHASE, IOI jnz . + 2;831	or	DMAPARAMS, DIRECTION;832	if ((ahc->features & AHC_CMD_CHAN) != 0) {833		/* We don't have any valid S/G elements */834		mvi	CCSGADDR, SG_PREFETCH_CNT;835	}836	test	SEQ_FLAGS, DPHASE	jz data_phase_initialize;837 838	/*839	 * If we re-enter the data phase after going through another840	 * phase, our transfer location has almost certainly been841	 * corrupted by the interveining, non-data, transfers.  Ask842	 * the host driver to fix us up based on the transfer residual.843	 */844	mvi	PDATA_REINIT	call set_seqint;845	jmp	data_phase_loop;846 847data_phase_initialize:848	/* We have seen a data phase for the first time */849	or	SEQ_FLAGS, DPHASE;850 851	/*852	 * Initialize the DMA address and counter from the SCB.853	 * Also set SCB_RESIDUAL_SGPTR, including the LAST_SEG854	 * flag in the highest byte of the data count.  We cannot855	 * modify the saved values in the SCB until we see a save856	 * data pointers message.857	 */858	if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {859		/* The lowest address byte must be loaded last. */860		mov	SCB_DATACNT[3] call set_hhaddr;861	}862	if ((ahc->features & AHC_CMD_CHAN) != 0) {863		bmov	HADDR, SCB_DATAPTR, 7;864		bmov	SCB_RESIDUAL_DATACNT[3], SCB_DATACNT[3], 5;865	} else {866		mvi	DINDEX, HADDR;867		mvi	SCB_DATAPTR	call bcopy_7;868		mvi	DINDEX, SCB_RESIDUAL_DATACNT + 3;869		mvi	SCB_DATACNT + 3 call bcopy_5;870	}871	if ((ahc->bugs & AHC_PCI_MWI_BUG) != 0 && ahc->pci_cachesize != 0) {872		call	calc_mwi_residual;873	}874	and	SCB_RESIDUAL_SGPTR[0], ~SG_FULL_RESID;875 876	if ((ahc->features & AHC_ULTRA2) == 0) {877		if ((ahc->features & AHC_CMD_CHAN) != 0) {878			bmov	STCNT, HCNT, 3;879		} else {880			call	set_stcnt_from_hcnt;881		}882	}883 884data_phase_loop:885	/* Guard against overruns */886	test	SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz data_phase_inbounds;887 888	/*889	 * Turn on `Bit Bucket' mode, wait until the target takes890	 * us to another phase, and then notify the host.891	 */892	and	DMAPARAMS, DIRECTION;893	mov	DFCNTRL, DMAPARAMS;894	or	SXFRCTL1,BITBUCKET;895	if ((ahc->features & AHC_DT) == 0) {896		test	SSTAT1,PHASEMIS	jz .;897	} else {898		test	SCSIPHASE, DATA_PHASE_MASK jnz .;899	}900	and	SXFRCTL1, ~BITBUCKET;901	mvi	DATA_OVERRUN call set_seqint;902	jmp	ITloop;903 904data_phase_inbounds:905	if ((ahc->features & AHC_ULTRA2) != 0) {906		mov	SINDEX, SCB_RESIDUAL_SGPTR[0];907		test	SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz . + 2;908		or	SINDEX, LAST_SEG;909		mov	SG_CACHE_PRE, SINDEX;910		mov	DFCNTRL, DMAPARAMS;911ultra2_dma_loop:912		call	idle_loop;913		/*914		 * The transfer is complete if either the last segment915		 * completes or the target changes phase.916		 */917		test	SG_CACHE_SHADOW, LAST_SEG_DONE jnz ultra2_dmafinish;918		if ((ahc->features & AHC_DT) == 0) {919			if ((ahc->flags & AHC_TARGETROLE) != 0) {920				 /*921				  * As a target, we control the phases,922				  * so ignore PHASEMIS.923				  */924				test	SSTAT0, TARGET jnz ultra2_dma_loop;925			}926			if ((ahc->flags & AHC_INITIATORROLE) != 0) {927				test	SSTAT1,PHASEMIS	jz ultra2_dma_loop;928			}929		} else {930			test	DFCNTRL, SCSIEN jnz ultra2_dma_loop;931		}932 933ultra2_dmafinish:934		/*935		 * The transfer has terminated either due to a phase936		 * change, and/or the completion of the last segment.937		 * We have two goals here.  Do as much other work938		 * as possible while the data fifo drains on a read939		 * and respond as quickly as possible to the standard940		 * messages (save data pointers/disconnect and command941		 * complete) that usually follow a data phase.942		 */943		if ((ahc->bugs & AHC_AUTOFLUSH_BUG) != 0) {944			/*945			 * On chips with broken auto-flush, start946			 * the flushing process now.  We'll poke947			 * the chip from time to time to keep the948			 * flush process going as we complete the949			 * data phase.950			 */951			or	DFCNTRL, FIFOFLUSH;952		}953		/*954		 * We assume that, even though data may still be955		 * transferring to the host, that the SCSI side of956		 * the DMA engine is now in a static state.  This957		 * allows us to update our notion of where we are958		 * in this transfer.959		 *960		 * If, by chance, we stopped before being able961		 * to fetch additional segments for this transfer,962		 * yet the last S/G was completely exhausted,963		 * call our idle loop until it is able to load964		 * another segment.  This will allow us to immediately965		 * pickup on the next segment on the next data phase.966		 *967		 * If we happened to stop on the last segment, then968		 * our residual information is still correct from969		 * the idle loop and there is no need to perform970		 * any fixups.971		 */972ultra2_ensure_sg:973		test	SG_CACHE_SHADOW, LAST_SEG jz ultra2_shvalid;974		/* Record if we've consumed all S/G entries */975		test	SSTAT2, SHVALID	jnz residuals_correct;976		or	SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL;977		jmp	residuals_correct;978 979ultra2_shvalid:980		test	SSTAT2, SHVALID	jnz sgptr_fixup;981		call	idle_loop;982		jmp	ultra2_ensure_sg;983 984sgptr_fixup:985		/*986		 * Fixup the residual next S/G pointer.  The S/G preload987		 * feature of the chip allows us to load two elements988		 * in addition to the currently active element.  We989		 * store the bottom byte of the next S/G pointer in990		 * the SG_CACEPTR register so we can restore the991		 * correct value when the DMA completes.  If the next992		 * sg ptr value has advanced to the point where higher993		 * bytes in the address have been affected, fix them994		 * too.995		 */996		test	SG_CACHE_SHADOW, 0x80 jz sgptr_fixup_done;997		test	SCB_RESIDUAL_SGPTR[0], 0x80 jnz sgptr_fixup_done;998		add	SCB_RESIDUAL_SGPTR[1], -1;999		adc	SCB_RESIDUAL_SGPTR[2], -1; 1000		adc	SCB_RESIDUAL_SGPTR[3], -1;1001sgptr_fixup_done:1002		and	SCB_RESIDUAL_SGPTR[0], SG_ADDR_MASK, SG_CACHE_SHADOW;1003		/* We are not the last seg */1004		and	SCB_RESIDUAL_DATACNT[3], ~SG_LAST_SEG;1005residuals_correct:1006		/*1007		 * Go ahead and shut down the DMA engine now.1008		 * In the future, we'll want to handle end of1009		 * transfer messages prior to doing this, but this1010		 * requires similar restructuring for pre-ULTRA21011		 * controllers.1012		 */1013		test	DMAPARAMS, DIRECTION jnz ultra2_fifoempty;1014ultra2_fifoflush:1015		if ((ahc->features & AHC_DT) == 0) {1016			if ((ahc->bugs & AHC_AUTOFLUSH_BUG) != 0) {1017				/*1018				 * On Rev A of the aic7890, the autoflush1019				 * feature doesn't function correctly.1020				 * Perform an explicit manual flush.  During1021				 * a manual flush, the FIFOEMP bit becomes1022				 * true every time the PCI FIFO empties1023				 * regardless of the state of the SCSI FIFO.1024				 * It can take up to 4 clock cycles for the1025				 * SCSI FIFO to get data into the PCI FIFO1026				 * and for FIFOEMP to de-assert.  Here we1027				 * guard against this condition by making1028				 * sure the FIFOEMP bit stays on for 5 full1029				 * clock cycles.1030				 */1031				or	DFCNTRL, FIFOFLUSH;1032				test	DFSTATUS, FIFOEMP jz ultra2_fifoflush;1033				test	DFSTATUS, FIFOEMP jz ultra2_fifoflush;1034				test	DFSTATUS, FIFOEMP jz ultra2_fifoflush;1035				test	DFSTATUS, FIFOEMP jz ultra2_fifoflush;1036			}1037			test	DFSTATUS, FIFOEMP jz ultra2_fifoflush;1038		} else {1039			/*1040			 * We enable the auto-ack feature on DT capable1041			 * controllers.  This means that the controller may1042			 * have already transferred some overrun bytes into1043			 * the data FIFO and acked them on the bus.  The only1044			 * way to detect this situation is to wait for1045			 * LAST_SEG_DONE to come true on a completed transfer1046			 * and then test to see if the data FIFO is non-empty.1047			 */1048			test	SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL1049				jz ultra2_wait_fifoemp;1050			test	SG_CACHE_SHADOW, LAST_SEG_DONE jz .;1051			/*1052			 * FIFOEMP can lag LAST_SEG_DONE.  Wait a few1053			 * clocks before calling this an overrun.1054			 */1055			test	DFSTATUS, FIFOEMP jnz ultra2_fifoempty;1056			test	DFSTATUS, FIFOEMP jnz ultra2_fifoempty;1057			test	DFSTATUS, FIFOEMP jnz ultra2_fifoempty;1058			/* Overrun */1059			jmp	data_phase_loop;1060ultra2_wait_fifoemp:1061			test	DFSTATUS, FIFOEMP jz .;1062		}1063ultra2_fifoempty:1064		/* Don't clobber an inprogress host data transfer */1065		test	DFSTATUS, MREQPEND	jnz ultra2_fifoempty;1066ultra2_dmahalt:1067		and     DFCNTRL, ~(SCSIEN|HDMAEN);1068		test	DFCNTRL, SCSIEN|HDMAEN jnz .;1069		if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {1070			/*1071			 * Keep HHADDR cleared for future, 32bit addressed1072			 * only, DMA operations.1073			 *1074			 * Due to bayonette style S/G handling, our residual1075			 * data must be "fixed up" once the transfer is halted.1076			 * Here we fixup the HSHADDR stored in the high byte1077			 * of the residual data cnt.  By postponing the fixup,1078			 * we can batch the clearing of HADDR with the fixup.1079			 * If we halted on the last segment, the residual is1080			 * already correct.   If we are not on the last1081			 * segment, copy the high address directly from HSHADDR.1082			 * We don't need to worry about maintaining the1083			 * SG_LAST_SEG flag as it will always be false in the1084			 * case where an update is required.1085			 */1086			or	DSCOMMAND1, HADDLDSEL0;1087			test	SG_CACHE_SHADOW, LAST_SEG jnz . + 2;1088			mov	SCB_RESIDUAL_DATACNT[3], SHADDR;1089			clr	HADDR;1090			and	DSCOMMAND1, ~HADDLDSEL0;1091		}1092	} else {1093		/* If we are the last SG block, tell the hardware. */1094		if ((ahc->bugs & AHC_PCI_MWI_BUG) != 01095		  && ahc->pci_cachesize != 0) {1096			test	MWI_RESIDUAL, 0xFF jnz dma_mid_sg;1097		}1098		test	SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz dma_mid_sg;1099		if ((ahc->flags & AHC_TARGETROLE) != 0) {1100			test	SSTAT0, TARGET jz dma_last_sg;1101			if ((ahc->bugs & AHC_TMODE_WIDEODD_BUG) != 0) {1102				test	DMAPARAMS, DIRECTION jz dma_mid_sg;1103			}1104		}1105dma_last_sg:1106		and	DMAPARAMS, ~WIDEODD;1107dma_mid_sg:1108		/* Start DMA data transfer. */1109		mov	DFCNTRL, DMAPARAMS;1110dma_loop:1111		if ((ahc->features & AHC_CMD_CHAN) != 0) {1112			call	idle_loop;1113		}1114		test	SSTAT0,DMADONE	jnz dma_dmadone;1115		test	SSTAT1,PHASEMIS	jz dma_loop;	/* ie. underrun */1116dma_phasemis:1117		/*1118		 * We will be "done" DMAing when the transfer count goes to1119		 * zero, or the target changes the phase (in light of this,1120		 * it makes sense that the DMA circuitry doesn't ACK when1121		 * PHASEMIS is active).  If we are doing a SCSI->Host transfer,1122		 * the data FIFO should be flushed auto-magically on STCNT=01123		 * or a phase change, so just wait for FIFO empty status.1124		 */1125dma_checkfifo:1126		test	DFCNTRL,DIRECTION	jnz dma_fifoempty;1127dma_fifoflush:1128		test	DFSTATUS,FIFOEMP	jz dma_fifoflush;1129dma_fifoempty:1130		/* Don't clobber an inprogress host data transfer */1131		test	DFSTATUS, MREQPEND	jnz dma_fifoempty;1132 1133		/*1134		 * Now shut off the DMA and make sure that the DMA1135		 * hardware has actually stopped.  Touching the DMA1136		 * counters, etc. while a DMA is active will result1137		 * in an ILLSADDR exception.1138		 */1139dma_dmadone:1140		and	DFCNTRL, ~(SCSIEN|SDMAEN|HDMAEN);1141dma_halt:1142		/*1143		 * Some revisions of the aic78XX have a problem where, if the1144		 * data fifo is full, but the PCI input latch is not empty, 1145		 * HDMAEN cannot be cleared.  The fix used here is to drain1146		 * the prefetched but unused data from the data fifo until1147		 * there is space for the input latch to drain.1148		 */1149		if ((ahc->bugs & AHC_PCI_2_1_RETRY_BUG) != 0) {1150			mov	NONE, DFDAT;1151		}1152		test	DFCNTRL, (SCSIEN|SDMAEN|HDMAEN) jnz dma_halt;1153 1154		/* See if we have completed this last segment */1155		test	STCNT[0], 0xff	jnz data_phase_finish;1156		test	STCNT[1], 0xff	jnz data_phase_finish;1157		test	STCNT[2], 0xff	jnz data_phase_finish;1158 1159		/*1160		 * Advance the scatter-gather pointers if needed 1161		 */1162		if ((ahc->bugs & AHC_PCI_MWI_BUG) != 01163		  && ahc->pci_cachesize != 0) {1164			test	MWI_RESIDUAL, 0xFF jz no_mwi_resid;1165			/*1166			 * Reload HADDR from SHADDR and setup the1167			 * count to be the size of our residual.1168			 */1169			if ((ahc->features & AHC_CMD_CHAN) != 0) {1170				bmov	HADDR, SHADDR, 4;1171				mov	HCNT, MWI_RESIDUAL;1172				bmov	HCNT[1], ALLZEROS, 2;1173			} else {1174				mvi	DINDEX, HADDR;1175				mvi	SHADDR call bcopy_4;1176				mov	MWI_RESIDUAL call set_hcnt;1177			}1178			clr	MWI_RESIDUAL;1179			jmp	sg_load_done;1180no_mwi_resid:1181		}1182		test	SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz sg_load;1183		or	SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL;1184		jmp	data_phase_finish;1185sg_load:1186		/*1187		 * Load the next SG element's data address and length1188		 * into the DMA engine.  If we don't have hardware1189		 * to perform a prefetch, we'll have to fetch the1190		 * segment from host memory first.1191		 */1192		if ((ahc->features & AHC_CMD_CHAN) != 0) {1193			/* Wait for the idle loop to complete */1194			test	CCSGCTL, CCSGEN jz . + 3;1195			call	idle_loop;1196			test	CCSGCTL, CCSGEN jnz . - 1;1197			bmov 	HADDR, CCSGRAM, 7;1198			/*1199			 * Workaround for flaky external SCB RAM1200			 * on certain aic7895 setups.  It seems1201			 * unable to handle direct transfers from1202			 * S/G ram to certain SCB locations.1203			 */1204			mov	SINDEX, CCSGRAM;1205			mov	SCB_RESIDUAL_DATACNT[3], SINDEX;1206		} else {1207			if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {1208				mov	ALLZEROS call set_hhaddr;1209			}1210			mvi	DINDEX, HADDR;1211			mvi	SCB_RESIDUAL_SGPTR	call bcopy_4;1212 1213			mvi	SG_SIZEOF	call set_hcnt;1214 1215			or	DFCNTRL, HDMAEN|DIRECTION|FIFORESET;1216 1217			call	dma_finish;1218 1219			mvi	DINDEX, HADDR;1220			call	dfdat_in_7;1221			mov	SCB_RESIDUAL_DATACNT[3], DFDAT;1222		}1223 1224		if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {1225			mov	SCB_RESIDUAL_DATACNT[3] call set_hhaddr;1226 1227			/*1228			 * The lowest address byte must be loaded1229			 * last as it triggers the computation of1230			 * some items in the PCI block.  The ULTRA21231			 * chips do this on PRELOAD.1232			 */1233			mov	HADDR, HADDR;1234		}1235		if ((ahc->bugs & AHC_PCI_MWI_BUG) != 01236		  && ahc->pci_cachesize != 0) {1237			call calc_mwi_residual;1238		}1239 1240		/* Point to the new next sg in memory */1241		call	sg_advance;1242 1243sg_load_done:1244		if ((ahc->features & AHC_CMD_CHAN) != 0) {1245			bmov	STCNT, HCNT, 3;1246		} else {1247			call	set_stcnt_from_hcnt;1248		}1249 1250		if ((ahc->flags & AHC_TARGETROLE) != 0) {1251			test	SSTAT0, TARGET jnz data_phase_loop;1252		}1253	}1254data_phase_finish:1255	/*1256	 * If the target has left us in data phase, loop through1257	 * the dma code again.  In the case of ULTRA2 adapters,1258	 * we should only loop if there is a data overrun.  For1259	 * all other adapters, we'll loop after each S/G element1260	 * is loaded as well as if there is an overrun.1261	 */1262	if ((ahc->flags & AHC_TARGETROLE) != 0) {1263		test	SSTAT0, TARGET jnz data_phase_done;1264	}1265	if ((ahc->flags & AHC_INITIATORROLE) != 0) {1266		test	SSTAT1, REQINIT jz .;1267		if ((ahc->features & AHC_DT) == 0) {1268			test	SSTAT1,PHASEMIS	jz data_phase_loop;1269		} else {1270			test	SCSIPHASE, DATA_PHASE_MASK jnz data_phase_loop;1271		}1272	}1273 1274data_phase_done:1275	/*1276	 * After a DMA finishes, save the SG and STCNT residuals back into1277	 * the SCB.  We use STCNT instead of HCNT, since it's a reflection1278	 * of how many bytes were transferred on the SCSI (as opposed to the1279	 * host) bus.1280	 */1281	if ((ahc->features & AHC_CMD_CHAN) != 0) {1282		/* Kill off any pending prefetch */1283		call	disable_ccsgen;1284	}1285 1286	if ((ahc->features & AHC_ULTRA2) == 0) {1287		/*1288		 * Clear the high address byte so that all other DMA1289		 * operations, which use 32bit addressing, can assume1290		 * HHADDR is 0.1291		 */1292		if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {1293			mov	ALLZEROS call set_hhaddr;1294		}1295	}1296 1297	/*1298	 * Update our residual information before the information is1299	 * lost by some other type of SCSI I/O (e.g. PIO).  If we have1300	 * transferred all data, no update is needed.1301	 *1302	 */1303	test	SCB_RESIDUAL_SGPTR, SG_LIST_NULL jnz residual_update_done;1304	if ((ahc->bugs & AHC_PCI_MWI_BUG) != 01305	  && ahc->pci_cachesize != 0) {1306		if ((ahc->features & AHC_CMD_CHAN) != 0) {1307			test	MWI_RESIDUAL, 0xFF jz bmov_resid;1308		}1309		mov	A, MWI_RESIDUAL;1310		add	SCB_RESIDUAL_DATACNT[0], A, STCNT[0];1311		clr	A;1312		adc	SCB_RESIDUAL_DATACNT[1], A, STCNT[1];1313		adc	SCB_RESIDUAL_DATACNT[2], A, STCNT[2];1314		clr	MWI_RESIDUAL;1315		if ((ahc->features & AHC_CMD_CHAN) != 0) {1316			jmp	. + 2;1317bmov_resid:1318			bmov	SCB_RESIDUAL_DATACNT, STCNT, 3;1319		}1320	} else if ((ahc->features & AHC_CMD_CHAN) != 0) {1321		bmov	SCB_RESIDUAL_DATACNT, STCNT, 3;1322	} else {1323		mov	SCB_RESIDUAL_DATACNT[0], STCNT[0];1324		mov	SCB_RESIDUAL_DATACNT[1], STCNT[1];1325		mov	SCB_RESIDUAL_DATACNT[2], STCNT[2];1326	}1327residual_update_done:1328	/*1329	 * Since we've been through a data phase, the SCB_RESID* fields1330	 * are now initialized.  Clear the full residual flag.1331	 */1332	and	SCB_SGPTR[0], ~SG_FULL_RESID;1333 1334	if ((ahc->features & AHC_ULTRA2) != 0) {1335		/* Clear the channel in case we return to data phase later */1336		or	SXFRCTL0, CLRSTCNT|CLRCHN;1337		or	SXFRCTL0, CLRSTCNT|CLRCHN;1338	}1339 1340	if ((ahc->flags & AHC_TARGETROLE) != 0) {1341		test	SEQ_FLAGS, DPHASE_PENDING jz ITloop;1342		and	SEQ_FLAGS, ~DPHASE_PENDING;1343		/*1344		 * For data-in phases, wait for any pending acks from the1345		 * initiator before changing phase.  We only need to1346		 * send Ignore Wide Residue messages for data-in phases.1347		 */1348		test	DFCNTRL, DIRECTION jz target_ITloop;1349		test	SSTAT1, REQINIT	jnz .;1350		test	SCB_LUN, SCB_XFERLEN_ODD jz target_ITloop;1351		test	SCSIRATE, WIDEXFER jz target_ITloop;1352		/*1353		 * Issue an Ignore Wide Residue Message.1354		 */1355		mvi	P_MESGIN|BSYO call change_phase;1356		mvi	MSG_IGN_WIDE_RESIDUE call target_outb;1357		mvi	1 call target_outb;1358		jmp	target_ITloop;1359	} else {1360		jmp	ITloop;1361	}1362 1363if ((ahc->flags & AHC_INITIATORROLE) != 0) {1364/*1365 * Command phase.  Set up the DMA registers and let 'er rip.1366 */1367p_command:1368	test	SEQ_FLAGS, NOT_IDENTIFIED jz p_command_okay;1369	mvi	PROTO_VIOLATION call set_seqint;1370p_command_okay:1371 1372	if ((ahc->features & AHC_ULTRA2) != 0) {1373		bmov	HCNT[0], SCB_CDB_LEN,  1;1374		bmov	HCNT[1], ALLZEROS, 2;1375		mvi	SG_CACHE_PRE, LAST_SEG;1376	} else if ((ahc->features & AHC_CMD_CHAN) != 0) {1377		bmov	STCNT[0], SCB_CDB_LEN, 1;1378		bmov	STCNT[1], ALLZEROS, 2;1379	} else {1380		mov	STCNT[0], SCB_CDB_LEN;1381		clr	STCNT[1];1382		clr	STCNT[2];1383	}1384	add	NONE, -13, SCB_CDB_LEN;1385	mvi	SCB_CDB_STORE jnc p_command_embedded;1386p_command_from_host:1387	if ((ahc->features & AHC_ULTRA2) != 0) {1388		bmov	HADDR[0], SCB_CDB_PTR, 4;1389		mvi	DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN|DIRECTION);1390	} else {1391		if ((ahc->features & AHC_CMD_CHAN) != 0) {1392			bmov	HADDR[0], SCB_CDB_PTR, 4;1393			bmov	HCNT, STCNT, 3;1394		} else {1395			mvi	DINDEX, HADDR;1396			mvi	SCB_CDB_PTR call bcopy_4;1397			mov	SCB_CDB_LEN call set_hcnt;1398		}1399		mvi	DFCNTRL, (SCSIEN|SDMAEN|HDMAEN|DIRECTION|FIFORESET);1400	}1401	jmp	p_command_xfer;1402p_command_embedded:1403	/*1404	 * The data fifo seems to require 4 byte aligned1405	 * transfers from the sequencer.  Force this to1406	 * be the case by clearing HADDR[0] even though1407	 * we aren't going to touch host memory.1408	 */1409	clr	HADDR[0];1410	if ((ahc->features & AHC_ULTRA2) != 0) {1411		mvi	DFCNTRL, (PRELOADEN|SCSIEN|DIRECTION);1412		bmov	DFDAT, SCB_CDB_STORE, 12; 1413	} else if ((ahc->features & AHC_CMD_CHAN) != 0) {1414		if ((ahc->flags & AHC_SCB_BTT) != 0) {1415			/*1416			 * On the 7895 the data FIFO will1417			 * get corrupted if you try to dump1418			 * data from external SCB memory into1419			 * the FIFO while it is enabled.  So,1420			 * fill the fifo and then enable SCSI1421			 * transfers.1422			 */1423			mvi	DFCNTRL, (DIRECTION|FIFORESET);1424		} else {1425			mvi	DFCNTRL, (SCSIEN|SDMAEN|DIRECTION|FIFORESET);1426		}1427		bmov	DFDAT, SCB_CDB_STORE, 12; 1428		if ((ahc->flags & AHC_SCB_BTT) != 0) {1429			mvi	DFCNTRL, (SCSIEN|SDMAEN|DIRECTION|FIFOFLUSH);1430		} else {1431			or	DFCNTRL, FIFOFLUSH;1432		}1433	} else {1434		mvi	DFCNTRL, (SCSIEN|SDMAEN|DIRECTION|FIFORESET);1435		call	copy_to_fifo_6;1436		call	copy_to_fifo_6;1437		or	DFCNTRL, FIFOFLUSH;1438	}1439p_command_xfer:1440	and	SEQ_FLAGS, ~NO_CDB_SENT;1441	if ((ahc->features & AHC_DT) == 0) {1442		test	SSTAT0, SDONE jnz . + 2;1443		test    SSTAT1, PHASEMIS jz . - 1;1444		/*1445		 * Wait for our ACK to go-away on it's own1446		 * instead of being killed by SCSIEN getting cleared.1447		 */1448		test	SCSISIGI, ACKI jnz .;1449	} else {1450		test	DFCNTRL, SCSIEN jnz .;1451	}1452	test	SSTAT0, SDONE jnz p_command_successful;1453	/*1454	 * Don't allow a data phase if the command1455	 * was not fully transferred.1456	 */1457	or	SEQ_FLAGS, NO_CDB_SENT;1458p_command_successful:1459	and	DFCNTRL, ~(SCSIEN|SDMAEN|HDMAEN);1460	test	DFCNTRL, (SCSIEN|SDMAEN|HDMAEN) jnz .;1461	jmp	ITloop;1462 1463/*1464 * Status phase.  Wait for the data byte to appear, then read it1465 * and store it into the SCB.1466 */1467p_status:1468	test	SEQ_FLAGS, NOT_IDENTIFIED jnz mesgin_proto_violation;1469p_status_okay:1470	mov	SCB_SCSI_STATUS, SCSIDATL;1471	or	SCB_CONTROL, STATUS_RCVD;1472	jmp	ITloop;1473 1474/*1475 * Message out phase.  If MSG_OUT is MSG_IDENTIFYFLAG, build a full1476 * indentify message sequence and send it to the target.  The host may1477 * override this behavior by setting the MK_MESSAGE bit in the SCB1478 * control byte.  This will cause us to interrupt the host and allow1479 * it to handle the message phase completely on its own.  If the bit1480 * associated with this target is set, we will also interrupt the host,1481 * thereby allowing it to send a message on the next selection regardless1482 * of the transaction being sent.1483 * 1484 * If MSG_OUT is == HOST_MSG, also interrupt the host and take a message.1485 * This is done to allow the host to send messages outside of an identify1486 * sequence while protecting the seqencer from testing the MK_MESSAGE bit1487 * on an SCB that might not be for the current nexus. (For example, a1488 * BDR message in response to a bad reselection would leave us pointed to1489 * an SCB that doesn't have anything to do with the current target).1490 *1491 * Otherwise, treat MSG_OUT as a 1 byte message to send (abort, abort tag,1492 * bus device reset).1493 *1494 * When there are no messages to send, MSG_OUT should be set to MSG_NOOP,1495 * in case the target decides to put us in this phase for some strange1496 * reason.1497 */1498p_mesgout_retry:1499	/* Turn on ATN for the retry */1500	if ((ahc->features & AHC_DT) == 0) {1501		or	SCSISIGO, ATNO, LASTPHASE;1502	} else {1503		mvi	SCSISIGO, ATNO;1504	}1505p_mesgout:1506	mov	SINDEX, MSG_OUT;1507	cmp	SINDEX, MSG_IDENTIFYFLAG jne p_mesgout_from_host;1508	test	SCB_CONTROL,MK_MESSAGE	jnz host_message_loop;1509p_mesgout_identify:1510	or	SINDEX, MSG_IDENTIFYFLAG|DISCENB, SAVED_LUN;1511	test	SCB_CONTROL, DISCENB jnz . + 2;1512	and	SINDEX, ~DISCENB;1513/*1514 * Send a tag message if TAG_ENB is set in the SCB control block.1515 * Use SCB_TAG (the position in the kernel's SCB array) as the tag value.1516 */1517p_mesgout_tag:1518	test	SCB_CONTROL,TAG_ENB jz  p_mesgout_onebyte;1519	mov	SCSIDATL, SINDEX;	/* Send the identify message */1520	call	phase_lock;1521	cmp	LASTPHASE, P_MESGOUT	jne p_mesgout_done;1522	and	SCSIDATL,TAG_ENB|SCB_TAG_TYPE,SCB_CONTROL;1523	call	phase_lock;1524	cmp	LASTPHASE, P_MESGOUT	jne p_mesgout_done;1525	mov	SCB_TAG	jmp p_mesgout_onebyte;1526/*1527 * Interrupt the driver, and allow it to handle this message1528 * phase and any required retries.1529 */1530p_mesgout_from_host:1531	cmp	SINDEX, HOST_MSG	jne p_mesgout_onebyte;1532	jmp	host_message_loop;1533 1534p_mesgout_onebyte:1535	mvi	CLRSINT1, CLRATNO;1536	mov	SCSIDATL, SINDEX;1537 1538/*1539 * If the next bus phase after ATN drops is message out, it means1540 * that the target is requesting that the last message(s) be resent.1541 */1542	call	phase_lock;1543	cmp	LASTPHASE, P_MESGOUT	je p_mesgout_retry;1544 1545p_mesgout_done:1546	mvi	CLRSINT1,CLRATNO;	/* Be sure to turn ATNO off */1547	mov	LAST_MSG, MSG_OUT;1548	mvi	MSG_OUT, MSG_NOOP;	/* No message left */1549	jmp	ITloop;1550 1551/*1552 * Message in phase.  Bytes are read using Automatic PIO mode.1553 */1554p_mesgin:1555	mvi	ACCUM		call inb_first;	/* read the 1st message byte */1556 1557	test	A,MSG_IDENTIFYFLAG	jnz mesgin_identify;1558	cmp	A,MSG_DISCONNECT	je mesgin_disconnect;1559	cmp	A,MSG_SAVEDATAPOINTER	je mesgin_sdptrs;1560	cmp	ALLZEROS,A		je mesgin_complete;1561	cmp	A,MSG_RESTOREPOINTERS	je mesgin_rdptrs;1562	cmp	A,MSG_IGN_WIDE_RESIDUE	je mesgin_ign_wide_residue;1563	cmp	A,MSG_NOOP		je mesgin_done;1564 1565/*1566 * Pushed message loop to allow the kernel to1567 * run it's own message state engine.  To avoid an1568 * extra nop instruction after signaling the kernel,1569 * we perform the phase_lock before checking to see1570 * if we should exit the loop and skip the phase_lock1571 * in the ITloop.  Performing back to back phase_locks1572 * shouldn't hurt, but why do it twice...1573 */1574host_message_loop:1575	mvi	HOST_MSG_LOOP call set_seqint;1576	call	phase_lock;1577	cmp	RETURN_1, EXIT_MSG_LOOP	je ITloop + 1;1578	jmp	host_message_loop;1579 1580mesgin_ign_wide_residue:1581if ((ahc->features & AHC_WIDE) != 0) {1582	test	SCSIRATE, WIDEXFER jz mesgin_reject;1583	/* Pull the residue byte */1584	mvi	ARG_1	call inb_next;1585	cmp	ARG_1, 0x01 jne mesgin_reject;1586	test	SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz . + 2;1587	test	SCB_LUN, SCB_XFERLEN_ODD jnz mesgin_done;1588	mvi	IGN_WIDE_RES call set_seqint;1589	jmp	mesgin_done;1590}1591 1592mesgin_proto_violation:1593	mvi	PROTO_VIOLATION call set_seqint;1594	jmp	mesgin_done;1595mesgin_reject:1596	mvi	MSG_MESSAGE_REJECT	call mk_mesg;1597mesgin_done:1598	mov	NONE,SCSIDATL;		/*dummy read from latch to ACK*/1599	jmp	ITloop;1600 1601/*1602 * We received a "command complete" message.  Put the SCB_TAG into the QOUTFIFO,1603 * and trigger a completion interrupt.  Before doing so, check to see if there1604 * is a residual or the status byte is something other than STATUS_GOOD (0).1605 * In either of these conditions, we upload the SCB back to the host so it can1606 * process this information.  In the case of a non zero status byte, we 1607 * additionally interrupt the kernel driver synchronously, allowing it to1608 * decide if sense should be retrieved.  If the kernel driver wishes to request1609 * sense, it will fill the kernel SCB with a request sense command, requeue1610 * it to the QINFIFO and tell us not to post to the QOUTFIFO by setting 1611 * RETURN_1 to SEND_SENSE.1612 */1613mesgin_complete:1614 1615	/*1616	 * If ATN is raised, we still want to give the target a message.1617	 * Perhaps there was a parity error on this last message byte.1618	 * Either way, the target should take us to message out phase1619	 * and then attempt to complete the command again.  We should use a1620	 * critical section here to guard against a timeout triggering1621	 * for this command and setting ATN while we are still processing1622	 * the completion.1623	test	SCSISIGI, ATNI jnz mesgin_done;1624	 */1625 1626	/*1627	 * If we are identified and have successfully sent the CDB,1628	 * any status will do.  Optimize this fast path.1629	 */1630	test	SCB_CONTROL, STATUS_RCVD jz mesgin_proto_violation;1631	test	SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT jz complete_accepted; 1632 1633	/*1634	 * If the target never sent an identify message but instead went1635	 * to mesgin to give an invalid message, let the host abort us.1636	 */1637	test	SEQ_FLAGS, NOT_IDENTIFIED jnz mesgin_proto_violation;1638 1639	/*1640	 * If we recevied good status but never successfully sent the1641	 * cdb, abort the command.1642	 */1643	test	SCB_SCSI_STATUS,0xff	jnz complete_accepted;1644	test	SEQ_FLAGS, NO_CDB_SENT jnz mesgin_proto_violation;1645 1646complete_accepted:1647	/*1648	 * See if we attempted to deliver a message but the target ingnored us.1649	 */1650	test	SCB_CONTROL, MK_MESSAGE jz . + 2;1651	mvi	MKMSG_FAILED call set_seqint;1652 1653	/*1654	 * Check for residuals1655	 */1656	test	SCB_SGPTR, SG_LIST_NULL jnz check_status;/* No xfer */1657	test	SCB_SGPTR, SG_FULL_RESID jnz upload_scb;/* Never xfered */1658	test	SCB_RESIDUAL_SGPTR, SG_LIST_NULL jz upload_scb;1659check_status:1660	test	SCB_SCSI_STATUS,0xff	jz complete;	/* Good Status? */1661upload_scb:1662	or	SCB_SGPTR, SG_RESID_VALID;1663	mvi	DMAPARAMS, FIFORESET;1664	mov	SCB_TAG		call dma_scb;1665	test	SCB_SCSI_STATUS, 0xff	jz complete;	/* Just a residual? */1666	mvi	BAD_STATUS call set_seqint;		/* let driver know */1667	cmp	RETURN_1, SEND_SENSE	jne complete;1668	call	add_scb_to_free_list;1669	jmp	await_busfree;1670complete:1671	mov	SCB_TAG call complete_post;1672	jmp	await_busfree;1673}1674 1675complete_post:1676	/* Post the SCBID in SINDEX and issue an interrupt */1677	call	add_scb_to_free_list;1678	mov	ARG_1, SINDEX;1679	if ((ahc->features & AHC_QUEUE_REGS) != 0) {1680		mov	A, SDSCB_QOFF;1681	} else {1682		mov	A, QOUTPOS;1683	}1684	mvi	QOUTFIFO_OFFSET call post_byte_setup;1685	mov	ARG_1 call post_byte;1686	if ((ahc->features & AHC_QUEUE_REGS) == 0) {1687		inc 	QOUTPOS;1688	}1689	mvi	INTSTAT,CMDCMPLT ret;1690 1691if ((ahc->flags & AHC_INITIATORROLE) != 0) {1692/*1693 * Is it a disconnect message?  Set a flag in the SCB to remind us1694 * and await the bus going free.  If this is an untagged transaction1695 * store the SCB id for it in our untagged target table for lookup on1696 * a reselection.1697 */1698mesgin_disconnect:1699	/*1700	 * If ATN is raised, we still want to give the target a message.1701	 * Perhaps there was a parity error on this last message byte1702	 * or we want to abort this command.  Either way, the target1703	 * should take us to message out phase and then attempt to1704	 * disconnect again.1705	 * XXX - Wait for more testing.1706	test	SCSISIGI, ATNI jnz mesgin_done;1707	 */1708	test	SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT1709		jnz mesgin_proto_violation;1710	or	SCB_CONTROL,DISCONNECTED;1711	if ((ahc->flags & AHC_PAGESCBS) != 0) {1712		call	add_scb_to_disc_list;1713	}1714	test	SCB_CONTROL, TAG_ENB jnz await_busfree;1715	mov	ARG_1, SCB_TAG;1716	and	SAVED_LUN, LID, SCB_LUN;1717	mov	SCB_SCSIID	call set_busy_target;1718	jmp	await_busfree;1719 1720/*1721 * Save data pointers message:1722 * Copying RAM values back to SCB, for Save Data Pointers message, but1723 * only if we've actually been into a data phase to change them.  This1724 * protects against bogus data in scratch ram and the residual counts1725 * since they are only initialized when we go into data_in or data_out.1726 * Ack the message as soon as possible.  For chips without S/G pipelining,1727 * we can only ack the message after SHADDR has been saved.  On these1728 * chips, SHADDR increments with every bus transaction, even PIO.1729 */1730mesgin_sdptrs:1731	if ((ahc->features & AHC_ULTRA2) != 0) {1732		mov	NONE,SCSIDATL;		/*dummy read from latch to ACK*/1733		test	SEQ_FLAGS, DPHASE	jz ITloop;1734	} else {1735		test	SEQ_FLAGS, DPHASE	jz mesgin_done;1736	}1737 1738	/*1739	 * If we are asked to save our position at the end of the1740	 * transfer, just mark us at the end rather than perform a1741	 * full save.1742	 */1743	test	SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz mesgin_sdptrs_full;1744	or	SCB_SGPTR, SG_LIST_NULL;1745	if ((ahc->features & AHC_ULTRA2) != 0) {1746		jmp	ITloop;1747	} else {1748		jmp	mesgin_done;1749	}1750 1751mesgin_sdptrs_full:1752 1753	/*1754	 * The SCB_SGPTR becomes the next one we'll download,1755	 * and the SCB_DATAPTR becomes the current SHADDR.1756	 * Use the residual number since STCNT is corrupted by1757	 * any message transfer.1758	 */1759	if ((ahc->features & AHC_CMD_CHAN) != 0) {1760		bmov	SCB_DATAPTR, SHADDR, 4;1761		if ((ahc->features & AHC_ULTRA2) == 0) {1762			mov	NONE,SCSIDATL;	/*dummy read from latch to ACK*/1763		}1764		bmov	SCB_DATACNT, SCB_RESIDUAL_DATACNT, 8;1765	} else {1766		mvi	DINDEX, SCB_DATAPTR;1767		mvi	SHADDR call bcopy_4;1768		mov	NONE,SCSIDATL;	/*dummy read from latch to ACK*/1769		mvi	SCB_RESIDUAL_DATACNT call bcopy_8;1770	}1771	jmp	ITloop;1772 1773/*1774 * Restore pointers message?  Data pointers are recopied from the1775 * SCB anytime we enter a data phase for the first time, so all1776 * we need to do is clear the DPHASE flag and let the data phase1777 * code do the rest.  We also reset/reallocate the FIFO to make1778 * sure we have a clean start for the next data or command phase.1779 */1780mesgin_rdptrs:1781	and	SEQ_FLAGS, ~DPHASE;		/*1782						 * We'll reload them1783						 * the next time through1784						 * the dataphase.1785						 */1786	or	SXFRCTL0, CLRSTCNT|CLRCHN;1787	jmp	mesgin_done;1788 1789/*1790 * Index into our Busy Target table.  SINDEX and DINDEX are modified1791 * upon return.  SCBPTR may be modified by this action.1792 */1793set_busy_target:1794	shr	DINDEX, 4, SINDEX;1795	if ((ahc->flags & AHC_SCB_BTT) != 0) {1796		mov	SCBPTR, SAVED_LUN;1797		add	DINDEX, SCB_64_BTT;1798	} else {1799		add	DINDEX, BUSY_TARGETS;1800	}1801	mov	DINDIR, ARG_1 ret;1802 1803/*1804 * Identify message?  For a reconnecting target, this tells us the lun1805 * that the reconnection is for - find the correct SCB and switch to it,1806 * clearing the "disconnected" bit so we don't "find" it by accident later.1807 */1808mesgin_identify:1809	/*1810	 * Determine whether a target is using tagged or non-tagged1811	 * transactions by first looking at the transaction stored in1812	 * the busy target array.  If there is no untagged transaction1813	 * for this target or the transaction is for a different lun, then1814	 * this must be a tagged transaction.1815	 */1816	shr	SINDEX, 4, SAVED_SCSIID;1817	and	SAVED_LUN, MSG_IDENTIFY_LUNMASK, A;1818	if ((ahc->flags & AHC_SCB_BTT) != 0) {1819		add	SINDEX, SCB_64_BTT;1820		mov	SCBPTR, SAVED_LUN;1821		if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {1822			add	NONE, -SCB_64_BTT, SINDEX;1823			jc	. + 2;1824			mvi	INTSTAT, OUT_OF_RANGE;1825			nop;1826			add	NONE, -(SCB_64_BTT + 16), SINDEX;1827			jnc	. + 2;1828			mvi	INTSTAT, OUT_OF_RANGE;1829			nop;1830		}1831	} else {1832		add	SINDEX, BUSY_TARGETS;1833		if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {1834			add	NONE, -BUSY_TARGETS, SINDEX;1835			jc	. + 2;1836			mvi	INTSTAT, OUT_OF_RANGE;1837			nop;1838			add	NONE, -(BUSY_TARGETS + 16), SINDEX;1839			jnc	. + 2;1840			mvi	INTSTAT, OUT_OF_RANGE;1841			nop;1842		}1843	}1844	mov	ARG_1, SINDIR;1845	cmp	ARG_1, SCB_LIST_NULL	je snoop_tag;1846	if ((ahc->flags & AHC_PAGESCBS) != 0) {1847		mov	ARG_1 call findSCB;1848	} else {1849		mov	SCBPTR, ARG_1;1850	}1851	if ((ahc->flags & AHC_SCB_BTT) != 0) {1852		jmp setup_SCB_id_lun_okay;1853	} else {1854		/*1855		 * We only allow one untagged command per-target1856		 * at a time.  So, if the lun doesn't match, look1857		 * for a tag message.1858		 */1859		and	A, LID, SCB_LUN;1860		cmp	SAVED_LUN, A	je setup_SCB_id_lun_okay;1861		if ((ahc->flags & AHC_PAGESCBS) != 0) {1862			/*1863			 * findSCB removes the SCB from the1864			 * disconnected list, so we must replace1865			 * it there should this SCB be for another1866			 * lun.1867			 */1868			call	cleanup_scb;1869		}1870	}1871 1872/*1873 * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message.1874 * If we get one, we use the tag returned to find the proper1875 * SCB.  With SCB paging, we must search for non-tagged1876 * transactions since the SCB may exist in any slot.  If we're not1877 * using SCB paging, we can use the tag as the direct index to the1878 * SCB.1879 */1880snoop_tag:1881	if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {1882		or	SEQ_FLAGS, 0x80;1883	}1884	mov	NONE,SCSIDATL;		/* ACK Identify MSG */1885	call	phase_lock;1886	if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {1887		or	SEQ_FLAGS, 0x1;1888	}1889	cmp	LASTPHASE, P_MESGIN	jne not_found;1890	if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {1891		or	SEQ_FLAGS, 0x2;1892	}1893	cmp	SCSIBUSL,MSG_SIMPLE_Q_TAG jne not_found;1894get_tag:1895	if ((ahc->flags & AHC_PAGESCBS) != 0) {1896		mvi	ARG_1	call inb_next;	/* tag value */1897		mov	ARG_1	call findSCB;1898	} else {1899		mvi	ARG_1	call inb_next;	/* tag value */1900		mov	SCBPTR, ARG_1;1901	}1902 1903/*1904 * Ensure that the SCB the tag points to is for1905 * an SCB transaction to the reconnecting target.1906 */1907setup_SCB:1908	if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {1909		or	SEQ_FLAGS, 0x4;1910	}1911	mov	A, SCB_SCSIID;1912	cmp	SAVED_SCSIID, A	jne not_found_cleanup_scb;1913	if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {1914		or	SEQ_FLAGS, 0x8;1915	}1916setup_SCB_id_okay:1917	and	A, LID, SCB_LUN;1918	cmp	SAVED_LUN, A	jne not_found_cleanup_scb;1919setup_SCB_id_lun_okay:1920	if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {1921		or	SEQ_FLAGS, 0x10;1922	}1923	test	SCB_CONTROL,DISCONNECTED jz not_found_cleanup_scb;1924	and	SCB_CONTROL,~DISCONNECTED;1925	test	SCB_CONTROL, TAG_ENB	jnz setup_SCB_tagged;1926	if ((ahc->flags & AHC_SCB_BTT) != 0) {1927		mov	A, SCBPTR;1928	}1929	mvi	ARG_1, SCB_LIST_NULL;1930	mov	SAVED_SCSIID	call	set_busy_target;1931	if ((ahc->flags & AHC_SCB_BTT) != 0) {1932		mov	SCBPTR, A;1933	}1934setup_SCB_tagged:1935	clr	SEQ_FLAGS;	/* make note of IDENTIFY */1936	call	set_transfer_settings;1937	/* See if the host wants to send a message upon reconnection */1938	test	SCB_CONTROL, MK_MESSAGE jz mesgin_done;1939	mvi	HOST_MSG	call mk_mesg;1940	jmp	mesgin_done;1941 1942not_found_cleanup_scb:1943	if ((ahc->flags & AHC_PAGESCBS) != 0) {1944		call	cleanup_scb;1945	}1946not_found:1947	mvi	NO_MATCH call set_seqint;1948	jmp	mesgin_done;1949 1950mk_mesg:1951	if ((ahc->features & AHC_DT) == 0) {1952		or	SCSISIGO, ATNO, LASTPHASE;1953	} else {1954		mvi	SCSISIGO, ATNO;1955	}1956	mov	MSG_OUT,SINDEX ret;1957 1958/*1959 * Functions to read data in Automatic PIO mode.1960 *1961 * According to Adaptec's documentation, an ACK is not sent on input from1962 * the target until SCSIDATL is read from.  So we wait until SCSIDATL is1963 * latched (the usual way), then read the data byte directly off the bus1964 * using SCSIBUSL.  When we have pulled the ATN line, or we just want to1965 * acknowledge the byte, then we do a dummy read from SCISDATL.  The SCSI1966 * spec guarantees that the target will hold the data byte on the bus until1967 * we send our ACK.1968 *1969 * The assumption here is that these are called in a particular sequence,1970 * and that REQ is already set when inb_first is called.  inb_{first,next}1971 * use the same calling convention as inb.1972 */1973inb_next_wait_perr:1974	mvi	PERR_DETECTED call set_seqint;1975	jmp	inb_next_wait;1976inb_next:1977	mov	NONE,SCSIDATL;		/*dummy read from latch to ACK*/1978inb_next_wait:1979	/*1980	 * If there is a parity error, wait for the kernel to1981	 * see the interrupt and prepare our message response1982	 * before continuing.1983	 */1984	test	SSTAT1, REQINIT	jz inb_next_wait;1985	test	SSTAT1, SCSIPERR jnz inb_next_wait_perr;1986inb_next_check_phase:1987	and	LASTPHASE, PHASE_MASK, SCSISIGI;1988	cmp	LASTPHASE, P_MESGIN jne mesgin_phasemis;1989inb_first:1990	mov	DINDEX,SINDEX;1991	mov	DINDIR,SCSIBUSL	ret;		/*read byte directly from bus*/1992inb_last:1993	mov	NONE,SCSIDATL ret;		/*dummy read from latch to ACK*/1994}1995 1996if ((ahc->flags & AHC_TARGETROLE) != 0) {1997/*1998 * Change to a new phase.  If we are changing the state of the I/O signal,1999 * from out to in, wait an additional data release delay before continuing.2000 */2001change_phase:2002	/* Wait for preceding I/O session to complete. */2003	test	SCSISIGI, ACKI jnz .;2004 2005	/* Change the phase */2006	and	DINDEX, IOI, SCSISIGI;2007	mov	SCSISIGO, SINDEX;2008	and	A, IOI, SINDEX;2009 2010	/*2011	 * If the data direction has changed, from2012	 * out (initiator driving) to in (target driving),2013	 * we must wait at least a data release delay plus2014	 * the normal bus settle delay. [SCSI III SPI 10.11.0]2015	 */2016	cmp 	DINDEX, A je change_phase_wait;2017	test	SINDEX, IOI jz change_phase_wait;2018	call	change_phase_wait;2019change_phase_wait:2020	nop;2021	nop;2022	nop;2023	nop ret;2024 2025/*2026 * Send a byte to an initiator in Automatic PIO mode.2027 */2028target_outb:2029	or	SXFRCTL0, SPIOEN;2030	test	SSTAT0, SPIORDY	jz .;2031	mov	SCSIDATL, SINDEX;2032	test	SSTAT0, SPIORDY	jz .;2033	and	SXFRCTL0, ~SPIOEN ret;2034}2035	2036/*2037 * Locate a disconnected SCB by SCBID.  Upon return, SCBPTR and SINDEX will2038 * be set to the position of the SCB.  If the SCB cannot be found locally,2039 * it will be paged in from host memory.  RETURN_2 stores the address of the2040 * preceding SCB in the disconnected list which can be used to speed up2041 * removal of the found SCB from the disconnected list.2042 */2043if ((ahc->flags & AHC_PAGESCBS) != 0) {2044BEGIN_CRITICAL;2045findSCB:2046	mov	A, SINDEX;			/* Tag passed in SINDEX */2047	cmp	DISCONNECTED_SCBH, SCB_LIST_NULL je findSCB_notFound;2048	mov	SCBPTR, DISCONNECTED_SCBH;	/* Initialize SCBPTR */2049	mvi	ARG_2, SCB_LIST_NULL;		/* Head of list */2050	jmp	findSCB_loop;2051findSCB_next:2052	cmp	SCB_NEXT, SCB_LIST_NULL je findSCB_notFound;2053	mov	ARG_2, SCBPTR;2054	mov	SCBPTR,SCB_NEXT;2055findSCB_loop:2056	cmp	SCB_TAG, A	jne findSCB_next;2057rem_scb_from_disc_list:2058	cmp	ARG_2, SCB_LIST_NULL	je rHead;2059	mov	DINDEX, SCB_NEXT;2060	mov	SINDEX, SCBPTR;2061	mov	SCBPTR, ARG_2;2062	mov	SCB_NEXT, DINDEX;2063	mov	SCBPTR, SINDEX ret;2064rHead:2065	mov	DISCONNECTED_SCBH,SCB_NEXT ret;2066END_CRITICAL;2067findSCB_notFound:2068	/*2069	 * We didn't find it.  Page in the SCB.2070	 */2071	mov	ARG_1, A; /* Save tag */2072	mov	ALLZEROS call get_free_or_disc_scb;2073	mvi	DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;2074	mov	ARG_1	jmp dma_scb;2075}2076 2077/*2078 * Prepare the hardware to post a byte to host memory given an2079 * index of (A + (256 * SINDEX)) and a base address of SHARED_DATA_ADDR.2080 */2081post_byte_setup:2082	mov	ARG_2, SINDEX;2083	if ((ahc->features & AHC_CMD_CHAN) != 0) {2084		mvi	DINDEX, CCHADDR;2085		mvi	SHARED_DATA_ADDR call	set_1byte_addr;2086		mvi	CCHCNT, 1;2087		mvi	CCSCBCTL, CCSCBRESET ret;2088	} else {2089		mvi	DINDEX, HADDR;2090		mvi	SHARED_DATA_ADDR call	set_1byte_addr;2091		mvi	1	call set_hcnt;2092		mvi	DFCNTRL, FIFORESET ret;2093	}2094 2095post_byte:2096	if ((ahc->features & AHC_CMD_CHAN) != 0) {2097		bmov	CCSCBRAM, SINDEX, 1;2098		or	CCSCBCTL, CCSCBEN|CCSCBRESET;2099		test	CCSCBCTL, CCSCBDONE jz .;2100		clr	CCSCBCTL ret;2101	} else {2102		mov	DFDAT, SINDEX;2103		or	DFCNTRL, HDMAEN|FIFOFLUSH;2104		jmp	dma_finish;2105	}2106 2107phase_lock_perr:2108	mvi	PERR_DETECTED call set_seqint;2109phase_lock:     2110	/*2111	 * If there is a parity error, wait for the kernel to2112	 * see the interrupt and prepare our message response2113	 * before continuing.2114	 */2115	test	SSTAT1, REQINIT jz phase_lock;2116	test	SSTAT1, SCSIPERR jnz phase_lock_perr;2117phase_lock_latch_phase:2118	if ((ahc->features & AHC_DT) == 0) {2119		and	SCSISIGO, PHASE_MASK, SCSISIGI;2120	}2121	and	LASTPHASE, PHASE_MASK, SCSISIGI ret;2122 2123if ((ahc->features & AHC_CMD_CHAN) == 0) {2124set_hcnt:2125	mov	HCNT[0], SINDEX;2126clear_hcnt:2127	clr	HCNT[1];2128	clr	HCNT[2] ret;2129 2130set_stcnt_from_hcnt:2131	mov	STCNT[0], HCNT[0];2132	mov	STCNT[1], HCNT[1];2133	mov	STCNT[2], HCNT[2] ret;2134 2135bcopy_8:2136	mov	DINDIR, SINDIR;2137bcopy_7:2138	mov	DINDIR, SINDIR;2139	mov	DINDIR, SINDIR;2140bcopy_5:2141	mov	DINDIR, SINDIR;2142bcopy_4:2143	mov	DINDIR, SINDIR;2144bcopy_3:2145	mov	DINDIR, SINDIR;2146	mov	DINDIR, SINDIR;2147	mov	DINDIR, SINDIR ret;2148}2149 2150if ((ahc->flags & AHC_TARGETROLE) != 0) {2151/*2152 * Setup addr assuming that A is an index into2153 * an array of 32byte objects, SINDEX contains2154 * the base address of that array, and DINDEX2155 * contains the base address of the location2156 * to store the indexed address.2157 */2158set_32byte_addr:2159	shr	ARG_2, 3, A;2160	shl	A, 5;2161	jmp	set_1byte_addr;2162}2163 2164/*2165 * Setup addr assuming that A is an index into2166 * an array of 64byte objects, SINDEX contains2167 * the base address of that array, and DINDEX2168 * contains the base address of the location2169 * to store the indexed address.2170 */2171set_64byte_addr:2172	shr	ARG_2, 2, A;2173	shl	A, 6;2174 2175/*2176 * Setup addr assuming that A + (ARG_2 * 256) is an2177 * index into an array of 1byte objects, SINDEX contains2178 * the base address of that array, and DINDEX contains2179 * the base address of the location to store the computed2180 * address.2181 */2182set_1byte_addr:2183	add     DINDIR, A, SINDIR;2184	mov     A, ARG_2;2185	adc	DINDIR, A, SINDIR;2186	clr	A;2187	adc	DINDIR, A, SINDIR;2188	adc	DINDIR, A, SINDIR ret;2189 2190/*2191 * Either post or fetch an SCB from host memory based on the2192 * DIRECTION bit in DMAPARAMS. The host SCB index is in SINDEX.2193 */2194dma_scb:2195	mov	A, SINDEX;2196	if ((ahc->features & AHC_CMD_CHAN) != 0) {2197		mvi	DINDEX, CCHADDR;2198		mvi	HSCB_ADDR call set_64byte_addr;2199		mov	CCSCBPTR, SCBPTR;2200		test	DMAPARAMS, DIRECTION jz dma_scb_tohost;2201		if ((ahc->flags & AHC_SCB_BTT) != 0) {2202			mvi	CCHCNT, SCB_DOWNLOAD_SIZE_64;2203		} else {2204			mvi	CCHCNT, SCB_DOWNLOAD_SIZE;2205		}2206		mvi	CCSCBCTL, CCARREN|CCSCBEN|CCSCBDIR|CCSCBRESET;2207		cmp	CCSCBCTL, CCSCBDONE|ARRDONE|CCARREN|CCSCBEN|CCSCBDIR jne .;2208		jmp	dma_scb_finish;2209dma_scb_tohost:2210		mvi	CCHCNT, SCB_UPLOAD_SIZE;2211		if ((ahc->features & AHC_ULTRA2) == 0) {2212			mvi	CCSCBCTL, CCSCBRESET;2213			bmov	CCSCBRAM, SCB_BASE, SCB_UPLOAD_SIZE;2214			or	CCSCBCTL, CCSCBEN|CCSCBRESET;2215			test	CCSCBCTL, CCSCBDONE jz .;2216		} else if ((ahc->bugs & AHC_SCBCHAN_UPLOAD_BUG) != 0) {2217			mvi	CCSCBCTL, CCARREN|CCSCBRESET;2218			cmp	CCSCBCTL, ARRDONE|CCARREN jne .;2219			mvi	CCHCNT, SCB_UPLOAD_SIZE;2220			mvi	CCSCBCTL, CCSCBEN|CCSCBRESET;2221			cmp	CCSCBCTL, CCSCBDONE|CCSCBEN jne .;2222		} else {2223			mvi	CCSCBCTL, CCARREN|CCSCBEN|CCSCBRESET;2224			cmp	CCSCBCTL, CCSCBDONE|ARRDONE|CCARREN|CCSCBEN jne .;2225		}2226dma_scb_finish:2227		clr	CCSCBCTL;2228		test	CCSCBCTL, CCARREN|CCSCBEN jnz .;2229		ret;2230	} else {2231		mvi	DINDEX, HADDR;2232		mvi	HSCB_ADDR call set_64byte_addr;2233		mvi	SCB_DOWNLOAD_SIZE call set_hcnt;2234		mov	DFCNTRL, DMAPARAMS;2235		test	DMAPARAMS, DIRECTION	jnz dma_scb_fromhost;2236		/* Fill it with the SCB data */2237copy_scb_tofifo:2238		mvi	SINDEX, SCB_BASE;2239		add	A, SCB_DOWNLOAD_SIZE, SINDEX;2240copy_scb_tofifo_loop:2241		call	copy_to_fifo_8;2242		cmp	SINDEX, A jne copy_scb_tofifo_loop;2243		or	DFCNTRL, HDMAEN|FIFOFLUSH;2244		jmp	dma_finish;2245dma_scb_fromhost:2246		mvi	DINDEX, SCB_BASE;2247		if ((ahc->bugs & AHC_PCI_2_1_RETRY_BUG) != 0) {2248			/*2249			 * The PCI module will only issue a PCI2250			 * retry if the data FIFO is empty.  If the2251			 * host disconnects in the middle of a2252			 * transfer, we must empty the fifo of all2253			 * available data to force the chip to2254			 * continue the transfer.  This does not2255			 * happen for SCSI transfers as the SCSI module2256			 * will drain the FIFO as data are made available.2257			 * When the hang occurs, we know that a multiple2258			 * of 8 bytes is in the FIFO because the PCI2259			 * module has an 8 byte input latch that only2260			 * dumps to the FIFO when HCNT == 0 or the2261			 * latch is full.2262			 */2263			clr	A;2264			/* Wait for at least 8 bytes of data to arrive. */2265dma_scb_hang_fifo:2266			test	DFSTATUS, FIFOQWDEMP jnz dma_scb_hang_fifo;2267dma_scb_hang_wait:2268			test	DFSTATUS, MREQPEND jnz dma_scb_hang_wait;2269			test	DFSTATUS, HDONE	jnz dma_scb_hang_dma_done;2270			test	DFSTATUS, HDONE	jnz dma_scb_hang_dma_done;2271			test	DFSTATUS, HDONE	jnz dma_scb_hang_dma_done;2272			/*2273			 * The PCI module no longer intends to perform2274			 * a PCI transaction.  Drain the fifo.2275			 */2276dma_scb_hang_dma_drain_fifo:2277			not	A, HCNT;2278			add	A, SCB_DOWNLOAD_SIZE+SCB_BASE+1;2279			and	A, ~0x7;2280			mov	DINDIR,DFDAT;2281			cmp	DINDEX, A jne . - 1;2282			cmp	DINDEX, SCB_DOWNLOAD_SIZE+SCB_BASE2283				je	dma_finish_nowait;2284			/* Restore A as the lines left to transfer. */2285			add	A, -SCB_BASE, DINDEX;2286			shr	A, 3;2287			jmp	dma_scb_hang_fifo;2288dma_scb_hang_dma_done:2289			and	DFCNTRL, ~HDMAEN;2290			test	DFCNTRL, HDMAEN jnz .;2291			add	SEQADDR0, A;2292		} else {2293			call	dma_finish;2294		}2295		call	dfdat_in_8;2296		call	dfdat_in_8;2297		call	dfdat_in_8;2298dfdat_in_8:2299		mov	DINDIR,DFDAT;2300dfdat_in_7:2301		mov	DINDIR,DFDAT;2302		mov	DINDIR,DFDAT;2303		mov	DINDIR,DFDAT;2304		mov	DINDIR,DFDAT;2305		mov	DINDIR,DFDAT;2306dfdat_in_2:2307		mov	DINDIR,DFDAT;2308		mov	DINDIR,DFDAT ret;2309	}2310 2311copy_to_fifo_8:2312	mov	DFDAT,SINDIR;2313	mov	DFDAT,SINDIR;2314copy_to_fifo_6:2315	mov	DFDAT,SINDIR;2316copy_to_fifo_5:2317	mov	DFDAT,SINDIR;2318copy_to_fifo_4:2319	mov	DFDAT,SINDIR;2320	mov	DFDAT,SINDIR;2321	mov	DFDAT,SINDIR;2322	mov	DFDAT,SINDIR ret;2323 2324/*2325 * Wait for DMA from host memory to data FIFO to complete, then disable2326 * DMA and wait for it to acknowledge that it's off.2327 */2328dma_finish:2329	test	DFSTATUS,HDONE	jz dma_finish;2330dma_finish_nowait:2331	/* Turn off DMA */2332	and	DFCNTRL, ~HDMAEN;2333	test	DFCNTRL, HDMAEN jnz .;2334	ret;2335 2336/*2337 * Restore an SCB that failed to match an incoming reselection2338 * to the correct/safe state.  If the SCB is for a disconnected2339 * transaction, it must be returned to the disconnected list.2340 * If it is not in the disconnected state, it must be free.2341 */2342cleanup_scb:2343	if ((ahc->flags & AHC_PAGESCBS) != 0) {2344		test	SCB_CONTROL,DISCONNECTED jnz add_scb_to_disc_list;2345	}2346add_scb_to_free_list:2347	if ((ahc->flags & AHC_PAGESCBS) != 0) {2348BEGIN_CRITICAL;2349		mov	SCB_NEXT, FREE_SCBH;2350		mvi	SCB_TAG, SCB_LIST_NULL;2351		mov	FREE_SCBH, SCBPTR ret;2352END_CRITICAL;2353	} else {2354		mvi	SCB_TAG, SCB_LIST_NULL ret;2355	}2356 2357if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {2358set_hhaddr:2359	or	DSCOMMAND1, HADDLDSEL0;2360	and	HADDR, SG_HIGH_ADDR_BITS, SINDEX;2361	and	DSCOMMAND1, ~HADDLDSEL0 ret;2362}2363 2364if ((ahc->flags & AHC_PAGESCBS) != 0) {2365get_free_or_disc_scb:2366BEGIN_CRITICAL;2367	cmp	FREE_SCBH, SCB_LIST_NULL jne dequeue_free_scb;2368	cmp	DISCONNECTED_SCBH, SCB_LIST_NULL jne dequeue_disc_scb;2369return_error:2370	mvi	NO_FREE_SCB call set_seqint;2371	mvi	SINDEX, SCB_LIST_NULL	ret;2372dequeue_disc_scb:2373	mov	SCBPTR, DISCONNECTED_SCBH;2374	mov	DISCONNECTED_SCBH, SCB_NEXT;2375END_CRITICAL;2376	mvi	DMAPARAMS, FIFORESET;2377	mov	SCB_TAG	jmp dma_scb;2378BEGIN_CRITICAL;2379dequeue_free_scb:2380	mov	SCBPTR, FREE_SCBH;2381	mov	FREE_SCBH, SCB_NEXT ret;2382END_CRITICAL;2383 2384add_scb_to_disc_list:2385/*2386 * Link this SCB into the DISCONNECTED list.  This list holds the2387 * candidates for paging out an SCB if one is needed for a new command.2388 * Modifying the disconnected list is a critical(pause dissabled) section.2389 */2390BEGIN_CRITICAL;2391	mov	SCB_NEXT, DISCONNECTED_SCBH;2392	mov	DISCONNECTED_SCBH, SCBPTR ret;2393END_CRITICAL;2394}2395set_seqint:2396	mov	INTSTAT, SINDEX;2397	nop;2398return:2399	ret;2400