/*
* Adaptec 274x/284x/294x device driver firmware for Linux and FreeBSD.
*
* Copyright (c) 1994-2001 Justin T. Gibbs.
* Copyright (c) 2000-2001 Adaptec Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* $FreeBSD: /repoman/r/ncvs/src/sys/dev/aic7xxx/aic7xxx.seq,v 1.123 2003/01/20 20:44:55 gibbs Exp $
*/
/*
* A few words on the waiting SCB list:
* After starting the selection hardware, we check for reconnecting targets
* as well as for our selection to complete just in case the reselection wins
* bus arbitration. The problem with this is that we must keep track of the
* SCB that we've already pulled from the QINFIFO and started the selection
* on just in case the reselection wins so that we can retry the selection at
* a later time. This problem cannot be resolved by holding a single entry
* in scratch ram since a reconnecting target can request sense and this will
* create yet another SCB waiting for selection. The solution used here is to
* use byte 27 of the SCB as a pseudo-next pointer and to thread a list
* of SCBs that are awaiting selection. Since 0-0xfe are valid SCB indexes,
* SCB_LIST_NULL is 0xff which is out of range. An entry is also added to
* this list everytime a request sense occurs or after completing a non-tagged
* command for which a second SCB has been queued. The sequencer will
* automatically consume the entries.
*/
bus_free_sel:
/*
* Turn off the selection hardware. We need to reset the
* selection request in order to perform a new selection.
*/
and SCSISEQ, TEMODE|ENSELI|ENRSELI|ENAUTOATNP;
and SIMODE1, ~ENBUSFREE;
poll_for_work:
call clear_target_state;
and SXFRCTL0, ~SPIOEN;
if ((ahc->features & AHC_ULTRA2) != 0) {
clr SCSIBUSL;
}
test SCSISEQ, ENSELO jnz poll_for_selection;
if ((ahc->features & AHC_TWIN) != 0) {
xor SBLKCTL,SELBUSB; /* Toggle to the other bus */
test SCSISEQ, ENSELO jnz poll_for_selection;
}
cmp WAITING_SCBH,SCB_LIST_NULL jne start_waiting;
poll_for_work_loop:
if ((ahc->features & AHC_TWIN) != 0) {
xor SBLKCTL,SELBUSB; /* Toggle to the other bus */
}
test SSTAT0, SELDO|SELDI jnz selection;
test_queue:
/* Has the driver posted any work for us? */
BEGIN_CRITICAL;
if ((ahc->features & AHC_QUEUE_REGS) != 0) {
test QOFF_CTLSTA, SCB_AVAIL jz poll_for_work_loop;
} else {
mov A, QINPOS;
cmp KERNEL_QINPOS, A je poll_for_work_loop;
}
mov ARG_1, NEXT_QUEUED_SCB;
/*
* We have at least one queued SCB now and we don't have any
* SCBs in the list of SCBs awaiting selection. Allocate a
* card SCB for the host's SCB and get to work on it.
*/
if ((ahc->flags & AHC_PAGESCBS) != 0) {
mov ALLZEROS call get_free_or_disc_scb;
} else {
/* In the non-paging case, the SCBID == hardware SCB index */
mov SCBPTR, ARG_1;
}
or SEQ_FLAGS2, SCB_DMA;
END_CRITICAL;
dma_queued_scb:
/*
* DMA the SCB from host ram into the current SCB location.
*/
mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
mov ARG_1 call dma_scb;
/*
* Check one last time to see if this SCB was canceled
* before we completed the DMA operation. If it was,
* the QINFIFO next pointer will not match our saved
* value.
*/
mov A, ARG_1;
BEGIN_CRITICAL;
cmp NEXT_QUEUED_SCB, A jne abort_qinscb;
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
cmp SCB_TAG, A je . + 2;
mvi SCB_MISMATCH call set_seqint;
}
mov NEXT_QUEUED_SCB, SCB_NEXT;
mov SCB_NEXT,WAITING_SCBH;
mov WAITING_SCBH, SCBPTR;
if ((ahc->features & AHC_QUEUE_REGS) != 0) {
mov NONE, SNSCB_QOFF;
} else {
inc QINPOS;
}
and SEQ_FLAGS2, ~SCB_DMA;
END_CRITICAL;
start_waiting:
/*
* Start the first entry on the waiting SCB list.
*/
mov SCBPTR, WAITING_SCBH;
call start_selection;
poll_for_selection:
/*
* Twin channel devices cannot handle things like SELTO
* interrupts on the "background" channel. So, while
* selecting, keep polling the current channel until
* either a selection or reselection occurs.
*/
test SSTAT0, SELDO|SELDI jz poll_for_selection;
selection:
/*
* We aren't expecting a bus free, so interrupt
* the kernel driver if it happens.
*/
mvi CLRSINT1,CLRBUSFREE;
if ((ahc->features & AHC_DT) == 0) {
or SIMODE1, ENBUSFREE;
}
/*
* Guard against a bus free after (re)selection
* but prior to enabling the busfree interrupt. SELDI
* and SELDO will be cleared in that case.
*/
test SSTAT0, SELDI|SELDO jz bus_free_sel;
test SSTAT0,SELDO jnz select_out;
select_in:
if ((ahc->flags & AHC_TARGETROLE) != 0) {
if ((ahc->flags & AHC_INITIATORROLE) != 0) {
test SSTAT0, TARGET jz initiator_reselect;
}
mvi CLRSINT0, CLRSELDI;
/*
* We've just been selected. Assert BSY and
* setup the phase for receiving messages
* from the target.
*/
mvi SCSISIGO, P_MESGOUT|BSYO;
/*
* Setup the DMA for sending the identify and
* command information.
*/
mvi SEQ_FLAGS, CMDPHASE_PENDING;
/* Initiator that selected us */
and SAVED_SCSIID, SELID_MASK, SELID;
/* The Target ID we were selected at */
if ((ahc->features & AHC_MULTI_TID) != 0) {
and A, OID, TARGIDIN;
} else if ((ahc->features & AHC_ULTRA2) != 0) {
and A, OID, SCSIID_ULTRA2;
} else {
and A, OID, SCSIID;
}
or SAVED_SCSIID, A;
if ((ahc->features & AHC_TWIN) != 0) {
test SBLKCTL, SELBUSB jz . + 2;
or SAVED_SCSIID, TWIN_CHNLB;
}
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, SAVED_SCSIID;
} else {
mov DFDAT, SAVED_SCSIID;
}
/*
* If ATN isn't asserted, the target isn't interested
* in talking to us. Go directly to bus free.
* XXX SCSI-1 may require us to assume lun 0 if
* ATN is false.
*/
test SCSISIGI, ATNI jz target_busfree;
/*
* Watch ATN closely now as we pull in messages from the
* initiator. We follow the guidlines from section 6.5
* of the SCSI-2 spec for what messages are allowed when.
*/
call target_inb;
/*
* Our first message must be one of IDENTIFY, ABORT, or
* BUS_DEVICE_RESET.
*/
test DINDEX, MSG_IDENTIFYFLAG jz host_target_message_loop;
/* Store for host */
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, DINDEX;
} else {
mov DFDAT, DINDEX;
}
and SAVED_LUN, MSG_IDENTIFY_LUNMASK, DINDEX;
/* Remember for disconnection decision */
test DINDEX, MSG_IDENTIFY_DISCFLAG jnz . + 2;
/* XXX Honor per target settings too */
or SEQ_FLAGS, NO_DISCONNECT;
test SCSISIGI, ATNI jz ident_messages_done;
call target_inb;
/*
* If this is a tagged request, the tagged message must
* immediately follow the identify. We test for a valid
* tag message by seeing if it is >= MSG_SIMPLE_Q_TAG and
* < MSG_IGN_WIDE_RESIDUE.
*/
add A, -MSG_SIMPLE_Q_TAG, DINDEX;
jnc ident_messages_done_msg_pending;
add A, -MSG_IGN_WIDE_RESIDUE, DINDEX;
jc ident_messages_done_msg_pending;
/* Store for host */
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, DINDEX;
} else {
mov DFDAT, DINDEX;
}
/*
* If the initiator doesn't feel like providing a tag number,
* we've got a failed selection and must transition to bus
* free.
*/
test SCSISIGI, ATNI jz target_busfree;
/*
* Store the tag for the host.
*/
call target_inb;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, DINDEX;
} else {
mov DFDAT, DINDEX;
}
mov INITIATOR_TAG, DINDEX;
or SEQ_FLAGS, TARGET_CMD_IS_TAGGED;
ident_messages_done:
/* Terminate the ident list */
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mvi CCSCBRAM, SCB_LIST_NULL;
} else {
mvi DFDAT, SCB_LIST_NULL;
}
or SEQ_FLAGS, TARG_CMD_PENDING;
test SEQ_FLAGS2, TARGET_MSG_PENDING
jnz target_mesgout_pending;
test SCSISIGI, ATNI jnz target_mesgout_continue;
jmp target_ITloop;
ident_messages_done_msg_pending:
or SEQ_FLAGS2, TARGET_MSG_PENDING;
jmp ident_messages_done;
/*
* Pushed message loop to allow the kernel to
* run its own target mode message state engine.
*/
host_target_message_loop:
mvi HOST_MSG_LOOP call set_seqint;
cmp RETURN_1, EXIT_MSG_LOOP je target_ITloop;
test SSTAT0, SPIORDY jz .;
jmp host_target_message_loop;
}
if ((ahc->flags & AHC_INITIATORROLE) != 0) {
/*
* Reselection has been initiated by a target. Make a note that we've been
* reselected, but haven't seen an IDENTIFY message from the target yet.
*/
initiator_reselect:
/* XXX test for and handle ONE BIT condition */
or SXFRCTL0, SPIOEN|CLRSTCNT|CLRCHN;
and SAVED_SCSIID, SELID_MASK, SELID;
if ((ahc->features & AHC_ULTRA2) != 0) {
and A, OID, SCSIID_ULTRA2;
} else {
and A, OID, SCSIID;
}
or SAVED_SCSIID, A;
if ((ahc->features & AHC_TWIN) != 0) {
test SBLKCTL, SELBUSB jz . + 2;
or SAVED_SCSIID, TWIN_CHNLB;
}
mvi CLRSINT0, CLRSELDI;
jmp ITloop;
}
start_selection:
/*
* If bus reset interrupts have been disabled (from a previous
* reset), re-enable them now. Resets are only of interest
* when we have outstanding transactions, so we can safely
* defer re-enabling the interrupt until, as an initiator,
* we start sending out transactions again.
*/
test SIMODE1, ENSCSIRST jnz . + 3;
mvi CLRSINT1, CLRSCSIRSTI;
or SIMODE1, ENSCSIRST;
if ((ahc->features & AHC_TWIN) != 0) {
and SINDEX,~SELBUSB,SBLKCTL;/* Clear channel select bit */
test SCB_SCSIID, TWIN_CHNLB jz . + 2;
or SINDEX, SELBUSB;
mov SBLKCTL,SINDEX; /* select channel */
}
initialize_scsiid:
if ((ahc->features & AHC_ULTRA2) != 0) {
mov SCSIID_ULTRA2, SCB_SCSIID;
} else if ((ahc->features & AHC_TWIN) != 0) {
and SCSIID, TWIN_TID|OID, SCB_SCSIID;
} else {
mov SCSIID, SCB_SCSIID;
}
if ((ahc->flags & AHC_TARGETROLE) != 0) {
mov SINDEX, SCSISEQ_TEMPLATE;
test SCB_CONTROL, TARGET_SCB jz . + 2;
or SINDEX, TEMODE;
mov SCSISEQ, SINDEX ret;
} else {
mov SCSISEQ, SCSISEQ_TEMPLATE ret;
}
/*
* Initialize transfer settings with SCB provided settings.
*/
set_transfer_settings:
if ((ahc->features & AHC_ULTRA) != 0) {
test SCB_CONTROL, ULTRAENB jz . + 2;
or SXFRCTL0, FAST20;
}
/*
* Initialize SCSIRATE with the appropriate value for this target.
*/
if ((ahc->features & AHC_ULTRA2) != 0) {
bmov SCSIRATE, SCB_SCSIRATE, 2 ret;
} else {
mov SCSIRATE, SCB_SCSIRATE ret;
}
if ((ahc->flags & AHC_TARGETROLE) != 0) {
/*
* We carefully toggle SPIOEN to allow us to return the
* message byte we receive so it can be checked prior to
* driving REQ on the bus for the next byte.
*/
target_inb:
/*
* Drive REQ on the bus by enabling SCSI PIO.
*/
or SXFRCTL0, SPIOEN;
/* Wait for the byte */
test SSTAT0, SPIORDY jz .;
/* Prevent our read from triggering another REQ */
and SXFRCTL0, ~SPIOEN;
/* Save latched contents */
mov DINDEX, SCSIDATL ret;
}
/*
* After the selection, remove this SCB from the "waiting SCB"
* list. This is achieved by simply moving our "next" pointer into
* WAITING_SCBH. Our next pointer will be set to null the next time this
* SCB is used, so don't bother with it now.
*/
select_out:
/* Turn off the selection hardware */
and SCSISEQ, TEMODE|ENSELI|ENRSELI|ENAUTOATNP, SCSISEQ;
mov SCBPTR, WAITING_SCBH;
mov WAITING_SCBH,SCB_NEXT;
mov SAVED_SCSIID, SCB_SCSIID;
mov SAVED_LUN, SCB_LUN;
call set_transfer_settings;
if ((ahc->flags & AHC_TARGETROLE) != 0) {
test SSTAT0, TARGET jz initiator_select;
or SXFRCTL0, CLRSTCNT|CLRCHN;
/*
* Put tag in connonical location since not
* all connections have an SCB.
*/
mov INITIATOR_TAG, SCB_TARGET_ITAG;
/*
* We've just re-selected an initiator.
* Assert BSY and setup the phase for
* sending our identify messages.
*/
mvi P_MESGIN|BSYO call change_phase;
mvi CLRSINT0, CLRSELDO;
/*
* Start out with a simple identify message.
*/
or SCB_LUN, MSG_IDENTIFYFLAG call target_outb;
/*
* If we are the result of a tagged command, send
* a simple Q tag and the tag id.
*/
test SCB_CONTROL, TAG_ENB jz . + 3;
mvi MSG_SIMPLE_Q_TAG call target_outb;
mov SCB_TARGET_ITAG call target_outb;
target_synccmd:
/*
* Now determine what phases the host wants us
* to go through.
*/
mov SEQ_FLAGS, SCB_TARGET_PHASES;
test SCB_CONTROL, MK_MESSAGE jz target_ITloop;
mvi P_MESGIN|BSYO call change_phase;
jmp host_target_message_loop;
target_ITloop:
/*
* Start honoring ATN signals now that
* we properly identified ourselves.
*/
test SCSISIGI, ATNI jnz target_mesgout;
test SEQ_FLAGS, CMDPHASE_PENDING jnz target_cmdphase;
test SEQ_FLAGS, DPHASE_PENDING jnz target_dphase;
test SEQ_FLAGS, SPHASE_PENDING jnz target_sphase;
/*
* No more work to do. Either disconnect or not depending
* on the state of NO_DISCONNECT.
*/
test SEQ_FLAGS, NO_DISCONNECT jz target_disconnect;
mvi TARG_IMMEDIATE_SCB, SCB_LIST_NULL;
call complete_target_cmd;
if ((ahc->flags & AHC_PAGESCBS) != 0) {
mov ALLZEROS call get_free_or_disc_scb;
}
cmp TARG_IMMEDIATE_SCB, SCB_LIST_NULL je .;
mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
mov TARG_IMMEDIATE_SCB call dma_scb;
call set_transfer_settings;
or SXFRCTL0, CLRSTCNT|CLRCHN;
jmp target_synccmd;
target_mesgout:
mvi SCSISIGO, P_MESGOUT|BSYO;
target_mesgout_continue:
call target_inb;
target_mesgout_pending:
and SEQ_FLAGS2, ~TARGET_MSG_PENDING;
/* Local Processing goes here... */
jmp host_target_message_loop;
target_busfree_wait:
/* Wait for preceding I/O session to complete. */
test SCSISIGI, ACKI jnz .;
target_busfree:
and SIMODE1, ~ENBUSFREE;
if ((ahc->features & AHC_ULTRA2) != 0) {
clr SCSIBUSL;
}
clr SCSISIGO;
mvi LASTPHASE, P_BUSFREE;
call complete_target_cmd;
jmp poll_for_work;
target_cmdphase:
/*
* The target has dropped ATN (doesn't want to abort or BDR)
* and we believe this selection to be valid. If the ring
* buffer for new commands is full, return busy or queue full.
*/
if ((ahc->features & AHC_HS_MAILBOX) != 0) {
and A, HOST_TQINPOS, HS_MAILBOX;
} else {
mov A, KERNEL_TQINPOS;
}
cmp TQINPOS, A jne tqinfifo_has_space;
mvi P_STATUS|BSYO call change_phase;
test SEQ_FLAGS, TARGET_CMD_IS_TAGGED jz . + 3;
mvi STATUS_QUEUE_FULL call target_outb;
jmp target_busfree_wait;
mvi STATUS_BUSY call target_outb;
jmp target_busfree_wait;
tqinfifo_has_space:
mvi P_COMMAND|BSYO call change_phase;
call target_inb;
mov A, DINDEX;
/* Store for host */
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, A;
} else {
mov DFDAT, A;
}
/*
* Determine the number of bytes to read
* based on the command group code via table lookup.
* We reuse the first 8 bytes of the TARG_SCSIRATE
* BIOS array for this table. Count is one less than
* the total for the command since we've already fetched
* the first byte.
*/
shr A, CMD_GROUP_CODE_SHIFT;
add SINDEX, CMDSIZE_TABLE, A;
mov A, SINDIR;
test A, 0xFF jz command_phase_done;
or SXFRCTL0, SPIOEN;
command_loop:
test SSTAT0, SPIORDY jz .;
cmp A, 1 jne . + 2;
and SXFRCTL0, ~SPIOEN; /* Last Byte */
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, SCSIDATL;
} else {
mov DFDAT, SCSIDATL;
}
dec A;
test A, 0xFF jnz command_loop;
command_phase_done:
and SEQ_FLAGS, ~CMDPHASE_PENDING;
jmp target_ITloop;
target_dphase:
/*
* Data phases on the bus are from the
* perspective of the initiator. The DMA
* code looks at LASTPHASE to determine the
* data direction of the DMA. Toggle it for
* target transfers.
*/
xor LASTPHASE, IOI, SCB_TARGET_DATA_DIR;
or SCB_TARGET_DATA_DIR, BSYO call change_phase;
jmp p_data;
target_sphase:
mvi P_STATUS|BSYO call change_phase;
mvi LASTPHASE, P_STATUS;
mov SCB_SCSI_STATUS call target_outb;
/* XXX Watch for ATN or parity errors??? */
mvi SCSISIGO, P_MESGIN|BSYO;
/* MSG_CMDCMPLT is 0, but we can't do an immediate of 0 */
mov ALLZEROS call target_outb;
jmp target_busfree_wait;
complete_target_cmd:
test SEQ_FLAGS, TARG_CMD_PENDING jnz . + 2;
mov SCB_TAG jmp complete_post;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
/* Set the valid byte */
mvi CCSCBADDR, 24;
mov CCSCBRAM, ALLONES;
mvi CCHCNT, 28;
or CCSCBCTL, CCSCBEN|CCSCBRESET;
test CCSCBCTL, CCSCBDONE jz .;
clr CCSCBCTL;
} else {
/* Set the valid byte */
or DFCNTRL, FIFORESET;
mvi DFWADDR, 3; /* Third 64bit word or byte 24 */
mov DFDAT, ALLONES;
mvi 28 call set_hcnt;
or DFCNTRL, HDMAEN|FIFOFLUSH;
call dma_finish;
}
inc TQINPOS;
mvi INTSTAT,CMDCMPLT ret;
}
if ((ahc->flags & AHC_INITIATORROLE) != 0) {
initiator_select:
or SXFRCTL0, SPIOEN|CLRSTCNT|CLRCHN;
/*
* As soon as we get a successful selection, the target
* should go into the message out phase since we have ATN
* asserted.
*/
mvi MSG_OUT, MSG_IDENTIFYFLAG;
mvi SEQ_FLAGS, NO_CDB_SENT;
mvi CLRSINT0, CLRSELDO;
/*
* Main loop for information transfer phases. Wait for the
* target to assert REQ before checking MSG, C/D and I/O for
* the bus phase.
*/
mesgin_phasemis:
ITloop:
call phase_lock;
mov A, LASTPHASE;
test A, ~P_DATAIN jz p_data;
cmp A,P_COMMAND je p_command;
cmp A,P_MESGOUT je p_mesgout;
cmp A,P_STATUS je p_status;
cmp A,P_MESGIN je p_mesgin;
mvi BAD_PHASE call set_seqint;
jmp ITloop; /* Try reading the bus again. */
await_busfree:
and SIMODE1, ~ENBUSFREE;
mov NONE, SCSIDATL; /* Ack the last byte */
if ((ahc->features & AHC_ULTRA2) != 0) {
clr SCSIBUSL; /* Prevent bit leakage durint SELTO */
}
and SXFRCTL0, ~SPIOEN;
test SSTAT1,REQINIT|BUSFREE jz .;
test SSTAT1, BUSFREE jnz poll_for_work;
mvi MISSED_BUSFREE call set_seqint;
}
clear_target_state:
/*
* We assume that the kernel driver may reset us
* at any time, even in the middle of a DMA, so
* clear DFCNTRL too.
*/
clr DFCNTRL;
or SXFRCTL0, CLRSTCNT|CLRCHN;
/*
* We don't know the target we will connect to,
* so default to narrow transfers to avoid
* parity problems.
*/
if ((ahc->features & AHC_ULTRA2) != 0) {
bmov SCSIRATE, ALLZEROS, 2;
} else {
clr SCSIRATE;
if ((ahc->features & AHC_ULTRA) != 0) {
and SXFRCTL0, ~(FAST20);
}
}
mvi LASTPHASE, P_BUSFREE;
/* clear target specific flags */
mvi SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT ret;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
disable_ccsgen:
test CCSGCTL, CCSGEN jz return;
test CCSGCTL, CCSGDONE jz .;
disable_ccsgen_fetch_done:
clr CCSGCTL;
test CCSGCTL, CCSGEN jnz .;
ret;
idle_loop:
/*
* Do we need any more segments for this transfer?
*/
test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jnz return;
/* Did we just finish fetching segs? */
cmp CCSGCTL, CCSGEN|CCSGDONE je idle_sgfetch_complete;
/* Are we actively fetching segments? */
test CCSGCTL, CCSGEN jnz return;
/*
* Do we have any prefetch left???
*/
cmp CCSGADDR, SG_PREFETCH_CNT jne idle_sg_avail;
/*
* Need to fetch segments, but we can only do that
* if the command channel is completely idle. Make
* sure we don't have an SCB prefetch going on.
*/
test CCSCBCTL, CCSCBEN jnz return;
/*
* We fetch a "cacheline aligned" and sized amount of data
* so we don't end up referencing a non-existent page.
* Cacheline aligned is in quotes because the kernel will
* set the prefetch amount to a reasonable level if the
* cacheline size is unknown.
*/
mvi CCHCNT, SG_PREFETCH_CNT;
and CCHADDR[0], SG_PREFETCH_ALIGN_MASK, SCB_RESIDUAL_SGPTR;
bmov CCHADDR[1], SCB_RESIDUAL_SGPTR[1], 3;
mvi CCSGCTL, CCSGEN|CCSGRESET ret;
idle_sgfetch_complete:
call disable_ccsgen_fetch_done;
and CCSGADDR, SG_PREFETCH_ADDR_MASK, SCB_RESIDUAL_SGPTR;
idle_sg_avail:
if ((ahc->features & AHC_ULTRA2) != 0) {
/* Does the hardware have space for another SG entry? */
test DFSTATUS, PRELOAD_AVAIL jz return;
bmov HADDR, CCSGRAM, 7;
test HCNT[0], 0x1 jz . + 2;
xor DATA_COUNT_ODD, 0x1;
bmov SCB_RESIDUAL_DATACNT[3], CCSGRAM, 1;
if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
mov SCB_RESIDUAL_DATACNT[3] call set_hhaddr;
}
call sg_advance;
mov SINDEX, SCB_RESIDUAL_SGPTR[0];
test DATA_COUNT_ODD, 0x1 jz . + 2;
or SINDEX, ODD_SEG;
test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz . + 2;
or SINDEX, LAST_SEG;
mov SG_CACHE_PRE, SINDEX;
/* Load the segment */
or DFCNTRL, PRELOADEN;
}
ret;
}
if ((ahc->bugs & AHC_PCI_MWI_BUG) != 0 && ahc->pci_cachesize != 0) {
/*
* Calculate the trailing portion of this S/G segment that cannot
* be transferred using memory write and invalidate PCI transactions.
* XXX Can we optimize this for PCI writes only???
*/
calc_mwi_residual:
/*
* If the ending address is on a cacheline boundary,
* there is no need for an extra segment.
*/
mov A, HCNT[0];
add A, A, HADDR[0];
and A, CACHESIZE_MASK;
test A, 0xFF jz return;
/*
* If the transfer is less than a cachline,
* there is no need for an extra segment.
*/
test HCNT[1], 0xFF jnz calc_mwi_residual_final;
test HCNT[2], 0xFF jnz calc_mwi_residual_final;
add NONE, INVERTED_CACHESIZE_MASK, HCNT[0];
jnc return;
p_data:
test SEQ_FLAGS,NOT_IDENTIFIED|NO_CDB_SENT jz p_data_allowed;
mvi PROTO_VIOLATION call set_seqint;
p_data_allowed:
if ((ahc->features & AHC_ULTRA2) != 0) {
mvi DMAPARAMS, PRELOADEN|SCSIEN|HDMAEN;
} else {
mvi DMAPARAMS, WIDEODD|SCSIEN|SDMAEN|HDMAEN|FIFORESET;
}
test LASTPHASE, IOI jnz . + 2;
or DMAPARAMS, DIRECTION;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
/* We don't have any valid S/G elements */
mvi CCSGADDR, SG_PREFETCH_CNT;
}
test SEQ_FLAGS, DPHASE jz data_phase_initialize;
/*
* If we re-enter the data phase after going through another
* phase, our transfer location has almost certainly been
* corrupted by the interveining, non-data, transfers. Ask
* the host driver to fix us up based on the transfer residual.
*/
mvi PDATA_REINIT call set_seqint;
jmp data_phase_loop;
data_phase_initialize:
/* We have seen a data phase for the first time */
or SEQ_FLAGS, DPHASE;
/*
* Initialize the DMA address and counter from the SCB.
* Also set SCB_RESIDUAL_SGPTR, including the LAST_SEG
* flag in the highest byte of the data count. We cannot
* modify the saved values in the SCB until we see a save
* data pointers message.
*/
if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
/* The lowest address byte must be loaded last. */
mov SCB_DATACNT[3] call set_hhaddr;
}
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov HADDR, SCB_DATAPTR, 7;
bmov SCB_RESIDUAL_DATACNT[3], SCB_DATACNT[3], 5;
} else {
mvi DINDEX, HADDR;
mvi SCB_DATAPTR call bcopy_7;
mvi DINDEX, SCB_RESIDUAL_DATACNT + 3;
mvi SCB_DATACNT + 3 call bcopy_5;
}
if ((ahc->bugs & AHC_PCI_MWI_BUG) != 0 && ahc->pci_cachesize != 0) {
call calc_mwi_residual;
}
and SCB_RESIDUAL_SGPTR[0], ~SG_FULL_RESID;
and DATA_COUNT_ODD, 0x1, HCNT[0];
data_phase_loop:
/* Guard against overruns */
test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz data_phase_inbounds;
/*
* Turn on `Bit Bucket' mode, wait until the target takes
* us to another phase, and then notify the host.
*/
and DMAPARAMS, DIRECTION;
mov DFCNTRL, DMAPARAMS;
or SXFRCTL1,BITBUCKET;
if ((ahc->features & AHC_DT) == 0) {
test SSTAT1,PHASEMIS jz .;
} else {
test SCSIPHASE, DATA_PHASE_MASK jnz .;
}
and SXFRCTL1, ~BITBUCKET;
mvi DATA_OVERRUN call set_seqint;
jmp ITloop;
data_phase_inbounds:
if ((ahc->features & AHC_ULTRA2) != 0) {
mov SINDEX, SCB_RESIDUAL_SGPTR[0];
test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz . + 2;
or SINDEX, LAST_SEG;
test DATA_COUNT_ODD, 0x1 jz . + 2;
or SINDEX, ODD_SEG;
mov SG_CACHE_PRE, SINDEX;
mov DFCNTRL, DMAPARAMS;
ultra2_dma_loop:
call idle_loop;
/*
* The transfer is complete if either the last segment
* completes or the target changes phase.
*/
test SG_CACHE_SHADOW, LAST_SEG_DONE jnz ultra2_dmafinish;
if ((ahc->features & AHC_DT) == 0) {
if ((ahc->flags & AHC_TARGETROLE) != 0) {
/*
* As a target, we control the phases,
* so ignore PHASEMIS.
*/
test SSTAT0, TARGET jnz ultra2_dma_loop;
}
if ((ahc->flags & AHC_INITIATORROLE) != 0) {
test SSTAT1,PHASEMIS jz ultra2_dma_loop;
}
} else {
test DFCNTRL, SCSIEN jnz ultra2_dma_loop;
}
ultra2_dmafinish:
/*
* The transfer has terminated either due to a phase
* change, and/or the completion of the last segment.
* We have two goals here. Do as much other work
* as possible while the data fifo drains on a read
* and respond as quickly as possible to the standard
* messages (save data pointers/disconnect and command
* complete) that usually follow a data phase.
*/
if ((ahc->bugs & AHC_AUTOFLUSH_BUG) != 0) {
/*
* On chips with broken auto-flush, start
* the flushing process now. We'll poke
* the chip from time to time to keep the
* flush process going as we complete the
* data phase.
*/
or DFCNTRL, FIFOFLUSH;
}
/*
* We assume that, even though data may still be
* transferring to the host, that the SCSI side of
* the DMA engine is now in a static state. This
* allows us to update our notion of where we are
* in this transfer.
*
* If, by chance, we stopped before being able
* to fetch additional segments for this transfer,
* yet the last S/G was completely exhausted,
* call our idle loop until it is able to load
* another segment. This will allow us to immediately
* pickup on the next segment on the next data phase.
*
* If we happened to stop on the last segment, then
* our residual information is still correct from
* the idle loop and there is no need to perform
* any fixups.
*/
ultra2_ensure_sg:
test SG_CACHE_SHADOW, LAST_SEG jz ultra2_shvalid;
/* Record if we've consumed all S/G entries */
test SSTAT2, SHVALID jnz residuals_correct;
or SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL;
jmp residuals_correct;
ultra2_shvalid:
test SSTAT2, SHVALID jnz sgptr_fixup;
call idle_loop;
jmp ultra2_ensure_sg;
sgptr_fixup:
/*
* Fixup the residual next S/G pointer. The S/G preload
* feature of the chip allows us to load two elements
* in addition to the currently active element. We
* store the bottom byte of the next S/G pointer in
* the SG_CACEPTR register so we can restore the
* correct value when the DMA completes. If the next
* sg ptr value has advanced to the point where higher
* bytes in the address have been affected, fix them
* too.
*/
test SG_CACHE_SHADOW, 0x80 jz sgptr_fixup_done;
test SCB_RESIDUAL_SGPTR[0], 0x80 jnz sgptr_fixup_done;
add SCB_RESIDUAL_SGPTR[1], -1;
adc SCB_RESIDUAL_SGPTR[2], -1;
adc SCB_RESIDUAL_SGPTR[3], -1;
sgptr_fixup_done:
and SCB_RESIDUAL_SGPTR[0], SG_ADDR_MASK, SG_CACHE_SHADOW;
clr DATA_COUNT_ODD;
test SG_CACHE_SHADOW, ODD_SEG jz . + 2;
or DATA_COUNT_ODD, 0x1;
clr SCB_RESIDUAL_DATACNT[3]; /* We are not the last seg */
residuals_correct:
/*
* Go ahead and shut down the DMA engine now.
* In the future, we'll want to handle end of
* transfer messages prior to doing this, but this
* requires similar restructuring for pre-ULTRA2
* controllers.
*/
test DMAPARAMS, DIRECTION jnz ultra2_fifoempty;
ultra2_fifoflush:
if ((ahc->features & AHC_DT) == 0) {
if ((ahc->bugs & AHC_AUTOFLUSH_BUG) != 0) {
/*
* On Rev A of the aic7890, the autoflush
* feature doesn't function correctly.
* Perform an explicit manual flush. During
* a manual flush, the FIFOEMP bit becomes
* true every time the PCI FIFO empties
* regardless of the state of the SCSI FIFO.
* It can take up to 4 clock cycles for the
* SCSI FIFO to get data into the PCI FIFO
* and for FIFOEMP to de-assert. Here we
* guard against this condition by making
* sure the FIFOEMP bit stays on for 5 full
* clock cycles.
*/
or DFCNTRL, FIFOFLUSH;
test DFSTATUS, FIFOEMP jz ultra2_fifoflush;
test DFSTATUS, FIFOEMP jz ultra2_fifoflush;
test DFSTATUS, FIFOEMP jz ultra2_fifoflush;
test DFSTATUS, FIFOEMP jz ultra2_fifoflush;
}
test DFSTATUS, FIFOEMP jz ultra2_fifoflush;
} else {
/*
* We enable the auto-ack feature on DT capable
* controllers. This means that the controller may
* have already transferred some overrun bytes into
* the data FIFO and acked them on the bus. The only
* way to detect this situation is to wait for
* LAST_SEG_DONE to come true on a completed transfer
* and then test to see if the data FIFO is non-empty.
*/
test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz . + 4;
test SG_CACHE_SHADOW, LAST_SEG_DONE jz .;
test DFSTATUS, FIFOEMP jnz ultra2_fifoempty;
/* Overrun */
jmp data_phase_loop;
test DFSTATUS, FIFOEMP jz .;
}
ultra2_fifoempty:
/* Don't clobber an inprogress host data transfer */
test DFSTATUS, MREQPEND jnz ultra2_fifoempty;
ultra2_dmahalt:
and DFCNTRL, ~(SCSIEN|HDMAEN);
test DFCNTRL, SCSIEN|HDMAEN jnz .;
if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
/*
* Keep HHADDR cleared for future, 32bit addressed
* only, DMA operations.
*
* Due to bayonette style S/G handling, our residual
* data must be "fixed up" once the transfer is halted.
* Here we fixup the HSHADDR stored in the high byte
* of the residual data cnt. By postponing the fixup,
* we can batch the clearing of HADDR with the fixup.
* If we halted on the last segment, the residual is
* already correct. If we are not on the last
* segment, copy the high address directly from HSHADDR.
* We don't need to worry about maintaining the
* SG_LAST_SEG flag as it will always be false in the
* case where an update is required.
*/
or DSCOMMAND1, HADDLDSEL0;
test SG_CACHE_SHADOW, LAST_SEG jnz . + 2;
mov SCB_RESIDUAL_DATACNT[3], SHADDR;
clr HADDR;
and DSCOMMAND1, ~HADDLDSEL0;
}
} else {
/* If we are the last SG block, tell the hardware. */
if ((ahc->bugs & AHC_PCI_MWI_BUG) != 0
&& ahc->pci_cachesize != 0) {
test MWI_RESIDUAL, 0xFF jnz dma_mid_sg;
}
test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz dma_mid_sg;
if ((ahc->flags & AHC_TARGETROLE) != 0) {
test SSTAT0, TARGET jz dma_last_sg;
if ((ahc->flags & AHC_TMODE_WIDEODD_BUG) != 0) {
test DMAPARAMS, DIRECTION jz dma_mid_sg;
}
}
dma_last_sg:
and DMAPARAMS, ~WIDEODD;
dma_mid_sg:
/* Start DMA data transfer. */
mov DFCNTRL, DMAPARAMS;
dma_loop:
if ((ahc->features & AHC_CMD_CHAN) != 0) {
call idle_loop;
}
test SSTAT0,DMADONE jnz dma_dmadone;
test SSTAT1,PHASEMIS jz dma_loop; /* ie. underrun */
dma_phasemis:
/*
* 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 off the DMA and make sure that the DMA
* hardware has actually stopped. Touching the DMA
* counters, etc. while a DMA is active will result
* in an ILLSADDR exception.
*/
dma_dmadone:
and DFCNTRL, ~(SCSIEN|SDMAEN|HDMAEN);
dma_halt:
/*
* Some revisions of the aic78XX 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 drain
* the prefetched but unused data from the data fifo until
* there is space for the input latch to drain.
*/
if ((ahc->bugs & AHC_PCI_2_1_RETRY_BUG) != 0) {
mov NONE, DFDAT;
}
test DFCNTRL, (SCSIEN|SDMAEN|HDMAEN) jnz dma_halt;
/* See if we have completed this last segment */
test STCNT[0], 0xff jnz data_phase_finish;
test STCNT[1], 0xff jnz data_phase_finish;
test STCNT[2], 0xff jnz data_phase_finish;
/*
* Advance the scatter-gather pointers if needed
*/
if ((ahc->bugs & AHC_PCI_MWI_BUG) != 0
&& ahc->pci_cachesize != 0) {
test MWI_RESIDUAL, 0xFF jz no_mwi_resid;
/*
* Reload HADDR from SHADDR and setup the
* count to be the size of our residual.
*/
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov HADDR, SHADDR, 4;
mov HCNT, MWI_RESIDUAL;
bmov HCNT[1], ALLZEROS, 2;
} else {
mvi DINDEX, HADDR;
mvi SHADDR call bcopy_4;
mov MWI_RESIDUAL call set_hcnt;
}
clr MWI_RESIDUAL;
jmp sg_load_done;
no_mwi_resid:
}
test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz sg_load;
or SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL;
jmp data_phase_finish;
sg_load:
/*
* Load the next SG element's data address and length
* into the DMA engine. If we don't have hardware
* to perform a prefetch, we'll have to fetch the
* segment from host memory first.
*/
if ((ahc->features & AHC_CMD_CHAN) != 0) {
/* Wait for the idle loop to complete */
test CCSGCTL, CCSGEN jz . + 3;
call idle_loop;
test CCSGCTL, CCSGEN jnz . - 1;
bmov HADDR, CCSGRAM, 7;
/*
* Workaround for flaky external SCB RAM
* on certain aic7895 setups. It seems
* unable to handle direct transfers from
* S/G ram to certain SCB locations.
*/
mov SINDEX, CCSGRAM;
mov SCB_RESIDUAL_DATACNT[3], SINDEX;
} else {
if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
mov ALLZEROS call set_hhaddr;
}
mvi DINDEX, HADDR;
mvi SCB_RESIDUAL_SGPTR call bcopy_4;
/*
* The lowest address byte must be loaded
* last as it triggers the computation of
* some items in the PCI block. The ULTRA2
* chips do this on PRELOAD.
*/
mov HADDR, HADDR;
}
if ((ahc->bugs & AHC_PCI_MWI_BUG) != 0
&& ahc->pci_cachesize != 0) {
call calc_mwi_residual;
}
/* Point to the new next sg in memory */
call sg_advance;
if ((ahc->flags & AHC_TARGETROLE) != 0) {
test SSTAT0, TARGET jnz data_phase_loop;
}
}
data_phase_finish:
/*
* If the target has left us in data phase, loop through
* the DMA code again. In the case of ULTRA2 adapters,
* we should only loop if there is a data overrun. For
* all other adapters, we'll loop after each S/G element
* is loaded as well as if there is an overrun.
*/
if ((ahc->flags & AHC_TARGETROLE) != 0) {
test SSTAT0, TARGET jnz data_phase_done;
}
if ((ahc->flags & AHC_INITIATORROLE) != 0) {
test SSTAT1, REQINIT jz .;
if ((ahc->features & AHC_DT) == 0) {
test SSTAT1,PHASEMIS jz data_phase_loop;
} else {
test SCSIPHASE, DATA_PHASE_MASK jnz data_phase_loop;
}
}
data_phase_done:
/*
* After a DMA finishes, save the SG and STCNT residuals back into
* the SCB. We use STCNT instead of HCNT, since it's a reflection
* of how many bytes were transferred on the SCSI (as opposed to the
* host) bus.
*/
if ((ahc->features & AHC_CMD_CHAN) != 0) {
/* Kill off any pending prefetch */
call disable_ccsgen;
}
if ((ahc->features & AHC_ULTRA2) == 0) {
/*
* Clear the high address byte so that all other DMA
* operations, which use 32bit addressing, can assume
* HHADDR is 0.
*/
if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
mov ALLZEROS call set_hhaddr;
}
}
/*
* Update our residual information before the information is
* lost by some other type of SCSI I/O (e.g. PIO). If we have
* transferred all data, no update is needed.
*
*/
test SCB_RESIDUAL_SGPTR, SG_LIST_NULL jnz residual_update_done;
if ((ahc->bugs & AHC_PCI_MWI_BUG) != 0
&& ahc->pci_cachesize != 0) {
if ((ahc->features & AHC_CMD_CHAN) != 0) {
test MWI_RESIDUAL, 0xFF jz bmov_resid;
}
mov A, MWI_RESIDUAL;
add SCB_RESIDUAL_DATACNT[0], A, STCNT[0];
clr A;
adc SCB_RESIDUAL_DATACNT[1], A, STCNT[1];
adc SCB_RESIDUAL_DATACNT[2], A, STCNT[2];
clr MWI_RESIDUAL;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
jmp . + 2;
bmov_resid:
bmov SCB_RESIDUAL_DATACNT, STCNT, 3;
}
} else if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov SCB_RESIDUAL_DATACNT, STCNT, 3;
} else {
mov SCB_RESIDUAL_DATACNT[0], STCNT[0];
mov SCB_RESIDUAL_DATACNT[1], STCNT[1];
mov SCB_RESIDUAL_DATACNT[2], STCNT[2];
}
residual_update_done:
/*
* Since we've been through a data phase, the SCB_RESID* fields
* are now initialized. Clear the full residual flag.
*/
and SCB_SGPTR[0], ~SG_FULL_RESID;
if ((ahc->features & AHC_ULTRA2) != 0) {
/* Clear the channel in case we return to data phase later */
or SXFRCTL0, CLRSTCNT|CLRCHN;
or SXFRCTL0, CLRSTCNT|CLRCHN;
}
if ((ahc->flags & AHC_TARGETROLE) != 0) {
test SEQ_FLAGS, DPHASE_PENDING jz ITloop;
and SEQ_FLAGS, ~DPHASE_PENDING;
/*
* For data-in phases, wait for any pending acks from the
* initiator before changing phase. We only need to
* send Ignore Wide Residue messages for data-in phases.
*/
test DFCNTRL, DIRECTION jz target_ITloop;
test SSTAT1, REQINIT jnz .;
test DATA_COUNT_ODD, 0x1 jz target_ITloop;
test SCSIRATE, WIDEXFER jz target_ITloop;
/*
* Issue an Ignore Wide Residue Message.
*/
mvi P_MESGIN|BSYO call change_phase;
mvi MSG_IGN_WIDE_RESIDUE call target_outb;
mvi 1 call target_outb;
jmp target_ITloop;
} else {
jmp ITloop;
}
if ((ahc->flags & AHC_INITIATORROLE) != 0) {
/*
* Command phase. Set up the DMA registers and let 'er rip.
*/
p_command:
test SEQ_FLAGS, NOT_IDENTIFIED jz p_command_okay;
mvi PROTO_VIOLATION call set_seqint;
p_command_okay:
if ((ahc->features & AHC_ULTRA2) != 0) {
bmov HCNT[0], SCB_CDB_LEN, 1;
bmov HCNT[1], ALLZEROS, 2;
mvi SG_CACHE_PRE, LAST_SEG;
} else if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov STCNT[0], SCB_CDB_LEN, 1;
bmov STCNT[1], ALLZEROS, 2;
} else {
mov STCNT[0], SCB_CDB_LEN;
clr STCNT[1];
clr STCNT[2];
}
add NONE, -13, SCB_CDB_LEN;
mvi SCB_CDB_STORE jnc p_command_embedded;
p_command_from_host:
if ((ahc->features & AHC_ULTRA2) != 0) {
bmov HADDR[0], SCB_CDB_PTR, 4;
mvi DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN|DIRECTION);
} else {
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov HADDR[0], SCB_CDB_PTR, 4;
bmov HCNT, STCNT, 3;
} else {
mvi DINDEX, HADDR;
mvi SCB_CDB_PTR call bcopy_4;
mov SCB_CDB_LEN call set_hcnt;
}
mvi DFCNTRL, (SCSIEN|SDMAEN|HDMAEN|DIRECTION|FIFORESET);
}
jmp p_command_xfer;
p_command_embedded:
/*
* The data fifo seems to require 4 byte aligned
* transfers from the sequencer. Force this to
* be the case by clearing HADDR[0] even though
* we aren't going to touch host memory.
*/
clr HADDR[0];
if ((ahc->features & AHC_ULTRA2) != 0) {
mvi DFCNTRL, (PRELOADEN|SCSIEN|DIRECTION);
bmov DFDAT, SCB_CDB_STORE, 12;
} else if ((ahc->features & AHC_CMD_CHAN) != 0) {
if ((ahc->flags & AHC_SCB_BTT) != 0) {
/*
* On the 7895 the data FIFO will
* get corrupted if you try to dump
* data from external SCB memory into
* the FIFO while it is enabled. So,
* fill the fifo and then enable SCSI
* transfers.
*/
mvi DFCNTRL, (DIRECTION|FIFORESET);
} else {
mvi DFCNTRL, (SCSIEN|SDMAEN|DIRECTION|FIFORESET);
}
bmov DFDAT, SCB_CDB_STORE, 12;
if ((ahc->flags & AHC_SCB_BTT) != 0) {
mvi DFCNTRL, (SCSIEN|SDMAEN|DIRECTION|FIFOFLUSH);
} else {
or DFCNTRL, FIFOFLUSH;
}
} else {
mvi DFCNTRL, (SCSIEN|SDMAEN|DIRECTION|FIFORESET);
call copy_to_fifo_6;
call copy_to_fifo_6;
or DFCNTRL, FIFOFLUSH;
}
p_command_xfer:
and SEQ_FLAGS, ~NO_CDB_SENT;
if ((ahc->features & AHC_DT) == 0) {
test SSTAT0, SDONE jnz . + 2;
test SSTAT1, PHASEMIS jz . - 1;
/*
* Wait for our ACK to go-away on its own
* instead of being killed by SCSIEN getting cleared.
*/
test SCSISIGI, ACKI jnz .;
} else {
test DFCNTRL, SCSIEN jnz .;
}
test SSTAT0, SDONE jnz p_command_successful;
/*
* Don't allow a data phase if the command
* was not fully transferred.
*/
or SEQ_FLAGS, NO_CDB_SENT;
p_command_successful:
and DFCNTRL, ~(SCSIEN|SDMAEN|HDMAEN);
test DFCNTRL, (SCSIEN|SDMAEN|HDMAEN) jnz .;
jmp ITloop;
/*
* Status phase. Wait for the data byte to appear, then read it
* and store it into the SCB.
*/
p_status:
test SEQ_FLAGS, NOT_IDENTIFIED jnz mesgin_proto_violation;
p_status_okay:
mov SCB_SCSI_STATUS, SCSIDATL;
or SCB_CONTROL, STATUS_RCVD;
jmp ITloop;
/*
* Message out phase. If MSG_OUT is MSG_IDENTIFYFLAG, build a full
* identify message sequence and send it to the target. The host may
* override this behavior by setting the MK_MESSAGE bit in the SCB
* control byte. This will cause us to interrupt the host and allow
* it to handle the message phase completely on its own. If the bit
* associated with this target is set, we will also interrupt the host,
* thereby allowing it to send a message on the next selection regardless
* of the transaction being sent.
*
* If MSG_OUT is == HOST_MSG, also interrupt the host and take a message.
* This is done to allow the host to send messages outside of an identify
* sequence while protecting the sequencer from testing the MK_MESSAGE bit
* on an SCB that might not be for the current nexus. (For example, a
* BDR message in response to a bad reselection would leave us pointed to
* an SCB that doesn't have anything to do with the current target).
*
* Otherwise, treat MSG_OUT as a 1 byte message to send (abort, abort tag,
* bus device reset).
*
* When there are no messages to send, MSG_OUT should be set to MSG_NOOP,
* in case the target decides to put us in this phase for some strange
* reason.
*/
p_mesgout_retry:
/* Turn on ATN for the retry */
if ((ahc->features & AHC_DT) == 0) {
or SCSISIGO, ATNO, LASTPHASE;
} else {
mvi SCSISIGO, ATNO;
}
p_mesgout:
mov SINDEX, MSG_OUT;
cmp SINDEX, MSG_IDENTIFYFLAG jne p_mesgout_from_host;
test SCB_CONTROL,MK_MESSAGE jnz host_message_loop;
p_mesgout_identify:
or SINDEX, MSG_IDENTIFYFLAG|DISCENB, SCB_LUN;
test SCB_CONTROL, DISCENB jnz . + 2;
and SINDEX, ~DISCENB;
/*
* Send a tag message if TAG_ENB is set in the SCB control block.
* Use SCB_TAG (the position in the kernel's SCB array) as the tag value.
*/
p_mesgout_tag:
test SCB_CONTROL,TAG_ENB jz p_mesgout_onebyte;
mov SCSIDATL, SINDEX; /* Send the identify message */
call phase_lock;
cmp LASTPHASE, P_MESGOUT jne p_mesgout_done;
and SCSIDATL,TAG_ENB|SCB_TAG_TYPE,SCB_CONTROL;
call phase_lock;
cmp LASTPHASE, P_MESGOUT jne p_mesgout_done;
mov SCB_TAG jmp p_mesgout_onebyte;
/*
* Interrupt the driver, and allow it to handle this message
* phase and any required retries.
*/
p_mesgout_from_host:
cmp SINDEX, HOST_MSG jne p_mesgout_onebyte;
jmp host_message_loop;
/*
* If the next bus phase after ATN drops is message out, it means
* that the target is requesting that the last message(s) be resent.
*/
call phase_lock;
cmp LASTPHASE, P_MESGOUT je p_mesgout_retry;
p_mesgout_done:
mvi CLRSINT1,CLRATNO; /* Be sure to turn ATNO off */
mov LAST_MSG, MSG_OUT;
mvi MSG_OUT, MSG_NOOP; /* No message left */
jmp ITloop;
/*
* Message in phase. Bytes are read using Automatic PIO mode.
*/
p_mesgin:
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_IGN_WIDE_RESIDUE je mesgin_ign_wide_residue;
cmp A,MSG_NOOP je mesgin_done;
/*
* Pushed message loop to allow the kernel to
* run its own message state engine. To avoid an
* extra nop instruction after signaling the kernel,
* we perform the phase_lock before checking to see
* if we should exit the loop and skip the phase_lock
* in the ITloop. Performing back to back phase_locks
* shouldn't hurt, but why do it twice...
*/
host_message_loop:
mvi HOST_MSG_LOOP call set_seqint;
call phase_lock;
cmp RETURN_1, EXIT_MSG_LOOP je ITloop + 1;
jmp host_message_loop;
mesgin_ign_wide_residue:
if ((ahc->features & AHC_WIDE) != 0) {
test SCSIRATE, WIDEXFER jz mesgin_reject;
/* Pull the residue byte */
mvi ARG_1 call inb_next;
cmp ARG_1, 0x01 jne mesgin_reject;
test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz . + 2;
test DATA_COUNT_ODD, 0x1 jz mesgin_done;
mvi IGN_WIDE_RES call set_seqint;
jmp mesgin_done;
}
/*
* We received a "command complete" message. 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, requeue
* it to the QINFIFO and tell us not to post to the QOUTFIFO by setting
* RETURN_1 to SEND_SENSE.
*/
mesgin_complete:
/*
* If ATN is raised, we still want to give the target a message.
* Perhaps there was a parity error on this last message byte.
* Either way, the target should take us to message out phase
* and then attempt to complete the command again. We should use a
* critical section here to guard against a timeout triggering
* for this command and setting ATN while we are still processing
* the completion.
test SCSISIGI, ATNI jnz mesgin_done;
*/
/*
* If we are identified and have successfully sent the CDB,
* any status will do. Optimize this fast path.
*/
test SCB_CONTROL, STATUS_RCVD jz mesgin_proto_violation;
test SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT jz complete_accepted;
/*
* If the target never sent an identify message but instead went
* to mesgin to give an invalid message, let the host abort us.
*/
test SEQ_FLAGS, NOT_IDENTIFIED jnz mesgin_proto_violation;
/*
* If we received good status but never successfully sent the
* cdb, abort the command.
*/
test SCB_SCSI_STATUS,0xff jnz complete_accepted;
test SEQ_FLAGS, NO_CDB_SENT jnz mesgin_proto_violation;
complete_accepted:
/*
* See if we attempted to deliver a message but the target ignored us.
*/
test SCB_CONTROL, MK_MESSAGE jz . + 2;
mvi MKMSG_FAILED call set_seqint;
/*
* Check for residuals
*/
test SCB_SGPTR, SG_LIST_NULL jnz check_status;/* No xfer */
test SCB_SGPTR, SG_FULL_RESID jnz upload_scb;/* Never xfered */
test SCB_RESIDUAL_SGPTR, SG_LIST_NULL jz upload_scb;
check_status:
test SCB_SCSI_STATUS,0xff jz complete; /* Good Status? */
upload_scb:
or SCB_SGPTR, SG_RESID_VALID;
mvi DMAPARAMS, FIFORESET;
mov SCB_TAG call dma_scb;
test SCB_SCSI_STATUS, 0xff jz complete; /* Just a residual? */
mvi BAD_STATUS call set_seqint; /* let driver know */
cmp RETURN_1, SEND_SENSE jne complete;
call add_scb_to_free_list;
jmp await_busfree;
complete:
mov SCB_TAG call complete_post;
jmp await_busfree;
}
complete_post:
/* Post the SCBID in SINDEX and issue an interrupt */
call add_scb_to_free_list;
mov ARG_1, SINDEX;
if ((ahc->features & AHC_QUEUE_REGS) != 0) {
mov A, SDSCB_QOFF;
} else {
mov A, QOUTPOS;
}
mvi QOUTFIFO_OFFSET call post_byte_setup;
mov ARG_1 call post_byte;
if ((ahc->features & AHC_QUEUE_REGS) == 0) {
inc QOUTPOS;
}
mvi INTSTAT,CMDCMPLT ret;
if ((ahc->flags & AHC_INITIATORROLE) != 0) {
/*
* Is it a disconnect message? Set a flag in the SCB to remind us
* and await the bus going free. If this is an untagged transaction
* store the SCB id for it in our untagged target table for lookup on
* a reselection.
*/
mesgin_disconnect:
/*
* If ATN is raised, we still want to give the target a message.
* Perhaps there was a parity error on this last message byte
* or we want to abort this command. Either way, the target
* should take us to message out phase and then attempt to
* disconnect again.
* XXX - Wait for more testing.
test SCSISIGI, ATNI jnz mesgin_done;
*/
test SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT
jnz mesgin_proto_violation;
or SCB_CONTROL,DISCONNECTED;
if ((ahc->flags & AHC_PAGESCBS) != 0) {
call add_scb_to_disc_list;
}
test SCB_CONTROL, TAG_ENB jnz await_busfree;
mov ARG_1, SCB_TAG;
mov SAVED_LUN, SCB_LUN;
mov SCB_SCSIID call set_busy_target;
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.
* Ack the message as soon as possible. For chips without S/G pipelining,
* we can only ack the message after SHADDR has been saved. On these
* chips, SHADDR increments with every bus transaction, even PIO.
*/
mesgin_sdptrs:
if ((ahc->features & AHC_ULTRA2) != 0) {
mov NONE,SCSIDATL; /*dummy read from latch to ACK*/
test SEQ_FLAGS, DPHASE jz ITloop;
} else {
test SEQ_FLAGS, DPHASE jz mesgin_done;
}
/*
* If we are asked to save our position at the end of the
* transfer, just mark us at the end rather than perform a
* full save.
*/
test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz mesgin_sdptrs_full;
or SCB_SGPTR, SG_LIST_NULL;
if ((ahc->features & AHC_ULTRA2) != 0) {
jmp ITloop;
} else {
jmp mesgin_done;
}
mesgin_sdptrs_full:
/*
* 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 ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov SCB_DATAPTR, SHADDR, 4;
if ((ahc->features & AHC_ULTRA2) == 0) {
mov NONE,SCSIDATL; /*dummy read from latch to ACK*/
}
bmov SCB_DATACNT, SCB_RESIDUAL_DATACNT, 8;
} else {
mvi DINDEX, SCB_DATAPTR;
mvi SHADDR call bcopy_4;
mov NONE,SCSIDATL; /*dummy read from latch to ACK*/
mvi SCB_RESIDUAL_DATACNT call bcopy_8;
}
jmp ITloop;
/*
* 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. We also reset/reallocate the FIFO to make
* sure we have a clean start for the next data or command phase.
*/
mesgin_rdptrs:
and SEQ_FLAGS, ~DPHASE; /*
* We'll reload them
* the next time through
* the dataphase.
*/
or SXFRCTL0, CLRSTCNT|CLRCHN;
jmp mesgin_done;
/*
* Index into our Busy Target table. SINDEX and DINDEX are modified
* upon return. SCBPTR may be modified by this action.
*/
set_busy_target:
shr DINDEX, 4, SINDEX;
if ((ahc->flags & AHC_SCB_BTT) != 0) {
mov SCBPTR, SAVED_LUN;
add DINDEX, SCB_64_BTT;
} else {
add DINDEX, BUSY_TARGETS;
}
mov DINDIR, ARG_1 ret;
/*
* 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:
/*
* Determine whether a target is using tagged or non-tagged
* transactions by first looking at the transaction stored in
* the busy target array. If there is no untagged transaction
* for this target or the transaction is for a different lun, then
* this must be a tagged transaction.
*/
shr SINDEX, 4, SAVED_SCSIID;
and SAVED_LUN, MSG_IDENTIFY_LUNMASK, A;
if ((ahc->flags & AHC_SCB_BTT) != 0) {
add SINDEX, SCB_64_BTT;
mov SCBPTR, SAVED_LUN;
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
add NONE, -SCB_64_BTT, SINDEX;
jc . + 2;
mvi INTSTAT, OUT_OF_RANGE;
nop;
add NONE, -(SCB_64_BTT + 16), SINDEX;
jnc . + 2;
mvi INTSTAT, OUT_OF_RANGE;
nop;
}
} else {
add SINDEX, BUSY_TARGETS;
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
add NONE, -BUSY_TARGETS, SINDEX;
jc . + 2;
mvi INTSTAT, OUT_OF_RANGE;
nop;
add NONE, -(BUSY_TARGETS + 16), SINDEX;
jnc . + 2;
mvi INTSTAT, OUT_OF_RANGE;
nop;
}
}
mov ARG_1, SINDIR;
cmp ARG_1, SCB_LIST_NULL je snoop_tag;
if ((ahc->flags & AHC_PAGESCBS) != 0) {
mov ARG_1 call findSCB;
} else {
mov SCBPTR, ARG_1;
}
if ((ahc->flags & AHC_SCB_BTT) != 0) {
jmp setup_SCB_id_lun_okay;
} else {
/*
* We only allow one untagged command per-target
* at a time. So, if the lun doesn't match, look
* for a tag message.
*/
mov A, SCB_LUN;
cmp SAVED_LUN, A je setup_SCB_id_lun_okay;
if ((ahc->flags & AHC_PAGESCBS) != 0) {
/*
* findSCB removes the SCB from the
* disconnected list, so we must replace
* it there should this SCB be for another
* lun.
*/
call cleanup_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, we must search for 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:
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
or SEQ_FLAGS, 0x80;
}
mov NONE,SCSIDATL; /* ACK Identify MSG */
call phase_lock;
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
or SEQ_FLAGS, 0x1;
}
cmp LASTPHASE, P_MESGIN jne not_found;
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
or SEQ_FLAGS, 0x2;
}
cmp SCSIBUSL,MSG_SIMPLE_Q_TAG jne not_found;
get_tag:
if ((ahc->flags & AHC_PAGESCBS) != 0) {
mvi ARG_1 call inb_next; /* tag value */
mov ARG_1 call findSCB;
} else {
mvi ARG_1 call inb_next; /* tag value */
mov SCBPTR, ARG_1;
}
/*
* Ensure that the SCB the tag points to is for
* an SCB transaction to the reconnecting target.
*/
setup_SCB:
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
or SEQ_FLAGS, 0x4;
}
mov A, SCB_SCSIID;
cmp SAVED_SCSIID, A jne not_found_cleanup_scb;
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
or SEQ_FLAGS, 0x8;
}
setup_SCB_id_okay:
mov A, SCB_LUN;
cmp SAVED_LUN, A jne not_found_cleanup_scb;
setup_SCB_id_lun_okay:
if ((ahc->flags & AHC_SEQUENCER_DEBUG) != 0) {
or SEQ_FLAGS, 0x10;
}
test SCB_CONTROL,DISCONNECTED jz not_found_cleanup_scb;
and SCB_CONTROL,~DISCONNECTED;
test SCB_CONTROL, TAG_ENB jnz setup_SCB_tagged;
if ((ahc->flags & AHC_SCB_BTT) != 0) {
mov A, SCBPTR;
}
mvi ARG_1, SCB_LIST_NULL;
mov SAVED_SCSIID call set_busy_target;
if ((ahc->flags & AHC_SCB_BTT) != 0) {
mov SCBPTR, A;
}
setup_SCB_tagged:
clr SEQ_FLAGS; /* make note of IDENTIFY */
call set_transfer_settings;
/* See if the host wants to send a message upon reconnection */
test SCB_CONTROL, MK_MESSAGE jz mesgin_done;
mvi HOST_MSG call mk_mesg;
jmp mesgin_done;
/*
* 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_wait_perr:
mvi PERR_DETECTED call set_seqint;
jmp inb_next_wait;
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 inb_next_wait_perr;
inb_next_check_phase:
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*/
}
if ((ahc->flags & AHC_TARGETROLE) != 0) {
/*
* Change to a new phase. If we are changing the state of the I/O signal,
* from out to in, wait an additional data release delay before continuing.
*/
change_phase:
/* Wait for preceding I/O session to complete. */
test SCSISIGI, ACKI jnz .;
/* Change the phase */
and DINDEX, IOI, SCSISIGI;
mov SCSISIGO, SINDEX;
and A, IOI, SINDEX;
/*
* If the data direction has changed, from
* out (initiator driving) to in (target driving),
* we must wait at least a data release delay plus
* the normal bus settle delay. [SCSI III SPI 10.11.0]
*/
cmp DINDEX, A je change_phase_wait;
test SINDEX, IOI jz change_phase_wait;
call change_phase_wait;
change_phase_wait:
nop;
nop;
nop;
nop ret;
/*
* Send a byte to an initiator in Automatic PIO mode.
*/
target_outb:
or SXFRCTL0, SPIOEN;
test SSTAT0, SPIORDY jz .;
mov SCSIDATL, SINDEX;
test SSTAT0, SPIORDY jz .;
and SXFRCTL0, ~SPIOEN ret;
}
/*
* Locate a disconnected SCB by SCBID. Upon return, SCBPTR and SINDEX will
* be set to the position of the SCB. If the SCB cannot be found locally,
* it will be paged in from host memory. RETURN_2 stores the address of the
* preceding SCB in the disconnected list which can be used to speed up
* removal of the found SCB from the disconnected list.
*/
if ((ahc->flags & AHC_PAGESCBS) != 0) {
BEGIN_CRITICAL;
findSCB:
mov A, SINDEX; /* Tag passed in SINDEX */
cmp DISCONNECTED_SCBH, SCB_LIST_NULL je findSCB_notFound;
mov SCBPTR, DISCONNECTED_SCBH; /* Initialize SCBPTR */
mvi ARG_2, SCB_LIST_NULL; /* Head of list */
jmp findSCB_loop;
findSCB_next:
cmp SCB_NEXT, SCB_LIST_NULL je findSCB_notFound;
mov ARG_2, SCBPTR;
mov SCBPTR,SCB_NEXT;
findSCB_loop:
cmp SCB_TAG, A jne findSCB_next;
rem_scb_from_disc_list:
cmp ARG_2, SCB_LIST_NULL je rHead;
mov DINDEX, SCB_NEXT;
mov SINDEX, SCBPTR;
mov SCBPTR, ARG_2;
mov SCB_NEXT, DINDEX;
mov SCBPTR, SINDEX ret;
rHead:
mov DISCONNECTED_SCBH,SCB_NEXT ret;
END_CRITICAL;
findSCB_notFound:
/*
* We didn't find it. Page in the SCB.
*/
mov ARG_1, A; /* Save tag */
mov ALLZEROS call get_free_or_disc_scb;
mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
mov ARG_1 jmp dma_scb;
}
/*
* Prepare the hardware to post a byte to host memory given an
* index of (A + (256 * SINDEX)) and a base address of SHARED_DATA_ADDR.
*/
post_byte_setup:
mov ARG_2, SINDEX;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mvi DINDEX, CCHADDR;
mvi SHARED_DATA_ADDR call set_1byte_addr;
mvi CCHCNT, 1;
mvi CCSCBCTL, CCSCBRESET ret;
} else {
mvi DINDEX, HADDR;
mvi SHARED_DATA_ADDR call set_1byte_addr;
mvi 1 call set_hcnt;
mvi DFCNTRL, FIFORESET ret;
}
post_byte:
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov CCSCBRAM, SINDEX, 1;
or CCSCBCTL, CCSCBEN|CCSCBRESET;
test CCSCBCTL, CCSCBDONE jz .;
clr CCSCBCTL ret;
} else {
mov DFDAT, SINDEX;
or DFCNTRL, HDMAEN|FIFOFLUSH;
jmp dma_finish;
}
phase_lock_perr:
mvi PERR_DETECTED call set_seqint;
phase_lock:
/*
* 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 phase_lock;
test SSTAT1, SCSIPERR jnz phase_lock_perr;
phase_lock_latch_phase:
if ((ahc->features & AHC_DT) == 0) {
and SCSISIGO, PHASE_MASK, SCSISIGI;
}
and LASTPHASE, PHASE_MASK, SCSISIGI ret;
if ((ahc->flags & AHC_TARGETROLE) != 0) {
/*
* Setup addr assuming that A is an index into
* an array of 32byte objects, SINDEX contains
* the base address of that array, and DINDEX
* contains the base address of the location
* to store the indexed address.
*/
set_32byte_addr:
shr ARG_2, 3, A;
shl A, 5;
jmp set_1byte_addr;
}
/*
* Setup addr assuming that A is an index into
* an array of 64byte objects, SINDEX contains
* the base address of that array, and DINDEX
* contains the base address of the location
* to store the indexed address.
*/
set_64byte_addr:
shr ARG_2, 2, A;
shl A, 6;
/*
* Setup addr assuming that A + (ARG_2 * 256) is an
* index into an array of 1byte objects, SINDEX contains
* the base address of that array, and DINDEX contains
* the base address of the location to store the computed
* address.
*/
set_1byte_addr:
add DINDIR, A, SINDIR;
mov A, ARG_2;
adc DINDIR, A, SINDIR;
clr A;
adc DINDIR, A, SINDIR;
adc DINDIR, A, SINDIR ret;
/*
* Either post or fetch an SCB from host memory based on the
* DIRECTION bit in DMAPARAMS. The host SCB index is in SINDEX.
*/
dma_scb:
mov A, SINDEX;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mvi DINDEX, CCHADDR;
mvi HSCB_ADDR call set_64byte_addr;
mov CCSCBPTR, SCBPTR;
test DMAPARAMS, DIRECTION jz dma_scb_tohost;
if ((ahc->flags & AHC_SCB_BTT) != 0) {
mvi CCHCNT, SCB_DOWNLOAD_SIZE_64;
} else {
mvi CCHCNT, SCB_DOWNLOAD_SIZE;
}
mvi CCSCBCTL, CCARREN|CCSCBEN|CCSCBDIR|CCSCBRESET;
cmp CCSCBCTL, CCSCBDONE|ARRDONE|CCARREN|CCSCBEN|CCSCBDIR jne .;
jmp dma_scb_finish;
dma_scb_tohost:
mvi CCHCNT, SCB_UPLOAD_SIZE;
if ((ahc->features & AHC_ULTRA2) == 0) {
mvi CCSCBCTL, CCSCBRESET;
bmov CCSCBRAM, SCB_BASE, SCB_UPLOAD_SIZE;
or CCSCBCTL, CCSCBEN|CCSCBRESET;
test CCSCBCTL, CCSCBDONE jz .;
} else if ((ahc->bugs & AHC_SCBCHAN_UPLOAD_BUG) != 0) {
mvi CCSCBCTL, CCARREN|CCSCBRESET;
cmp CCSCBCTL, ARRDONE|CCARREN jne .;
mvi CCHCNT, SCB_UPLOAD_SIZE;
mvi CCSCBCTL, CCSCBEN|CCSCBRESET;
cmp CCSCBCTL, CCSCBDONE|CCSCBEN jne .;
} else {
mvi CCSCBCTL, CCARREN|CCSCBEN|CCSCBRESET;
cmp CCSCBCTL, CCSCBDONE|ARRDONE|CCARREN|CCSCBEN jne .;
}
dma_scb_finish:
clr CCSCBCTL;
test CCSCBCTL, CCARREN|CCSCBEN jnz .;
ret;
} else {
mvi DINDEX, HADDR;
mvi HSCB_ADDR call set_64byte_addr;
mvi SCB_DOWNLOAD_SIZE call set_hcnt;
mov DFCNTRL, DMAPARAMS;
test DMAPARAMS, DIRECTION jnz dma_scb_fromhost;
/* Fill it with the SCB data */
copy_scb_tofifo:
mvi SINDEX, SCB_BASE;
add A, SCB_DOWNLOAD_SIZE, SINDEX;
copy_scb_tofifo_loop:
call copy_to_fifo_8;
cmp SINDEX, A jne copy_scb_tofifo_loop;
or DFCNTRL, HDMAEN|FIFOFLUSH;
jmp dma_finish;
dma_scb_fromhost:
mvi DINDEX, SCB_BASE;
if ((ahc->bugs & AHC_PCI_2_1_RETRY_BUG) != 0) {
/*
* The PCI module will only issue a PCI
* retry if the data FIFO is empty. If the
* host disconnects in the middle of a
* transfer, we must empty the fifo of all
* available data to force the chip to
* continue the transfer. This does not
* happen for SCSI transfers as the SCSI module
* will drain the FIFO as data are made available.
* When the hang occurs, we know that a multiple
* of 8 bytes is in the FIFO because the PCI
* module has an 8 byte input latch that only
* dumps to the FIFO when HCNT == 0 or the
* latch is full.
*/
clr A;
/* Wait for at least 8 bytes of data to arrive. */
dma_scb_hang_fifo:
test DFSTATUS, FIFOQWDEMP jnz dma_scb_hang_fifo;
dma_scb_hang_wait:
test DFSTATUS, MREQPEND jnz dma_scb_hang_wait;
test DFSTATUS, HDONE jnz dma_scb_hang_dma_done;
test DFSTATUS, HDONE jnz dma_scb_hang_dma_done;
test DFSTATUS, HDONE jnz dma_scb_hang_dma_done;
/*
* The PCI module no longer intends to perform
* a PCI transaction. Drain the fifo.
*/
dma_scb_hang_dma_drain_fifo:
not A, HCNT;
add A, SCB_DOWNLOAD_SIZE+SCB_BASE+1;
and A, ~0x7;
mov DINDIR,DFDAT;
cmp DINDEX, A jne . - 1;
cmp DINDEX, SCB_DOWNLOAD_SIZE+SCB_BASE
je dma_finish_nowait;
/* Restore A as the lines left to transfer. */
add A, -SCB_BASE, DINDEX;
shr A, 3;
jmp dma_scb_hang_fifo;
dma_scb_hang_dma_done:
and DFCNTRL, ~HDMAEN;
test DFCNTRL, HDMAEN jnz .;
add SEQADDR0, A;
} else {
call dma_finish;
}
call dfdat_in_8;
call dfdat_in_8;
call dfdat_in_8;
dfdat_in_8:
mov DINDIR,DFDAT;
dfdat_in_7:
mov DINDIR,DFDAT;
mov DINDIR,DFDAT;
mov DINDIR,DFDAT;
mov DINDIR,DFDAT;
mov DINDIR,DFDAT;
dfdat_in_2:
mov DINDIR,DFDAT;
mov DINDIR,DFDAT ret;
}
/*
* Wait for DMA from host memory to data FIFO to complete, then disable
* DMA and wait for it to acknowledge that it's off.
*/
dma_finish:
test DFSTATUS,HDONE jz dma_finish;
dma_finish_nowait:
/* Turn off DMA */
and DFCNTRL, ~HDMAEN;
test DFCNTRL, HDMAEN jnz .;
ret;
/*
* Restore an SCB that failed to match an incoming reselection
* to the correct/safe state. If the SCB is for a disconnected
* transaction, it must be returned to the disconnected list.
* If it is not in the disconnected state, it must be free.
*/
cleanup_scb:
if ((ahc->flags & AHC_PAGESCBS) != 0) {
test SCB_CONTROL,DISCONNECTED jnz add_scb_to_disc_list;
}
add_scb_to_free_list:
if ((ahc->flags & AHC_PAGESCBS) != 0) {
BEGIN_CRITICAL;
mov SCB_NEXT, FREE_SCBH;
mvi SCB_TAG, SCB_LIST_NULL;
mov FREE_SCBH, SCBPTR ret;
END_CRITICAL;
} else {
mvi SCB_TAG, SCB_LIST_NULL ret;
}
if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
set_hhaddr:
or DSCOMMAND1, HADDLDSEL0;
and HADDR, SG_HIGH_ADDR_BITS, SINDEX;
and DSCOMMAND1, ~HADDLDSEL0 ret;
}
add_scb_to_disc_list:
/*
* Link this SCB into the DISCONNECTED list. This list holds the
* candidates for paging out an SCB if one is needed for a new command.
* Modifying the disconnected list is a critical(pause dissabled) section.
*/
BEGIN_CRITICAL;
mov SCB_NEXT, DISCONNECTED_SCBH;
mov DISCONNECTED_SCBH, SCBPTR ret;
END_CRITICAL;
}
set_seqint:
mov INTSTAT, SINDEX;
nop;
return:
ret;
