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freebsd-skq/sys/dev/aic7xxx/aic7xxx.seq
Justin T. Gibbs 0f39fbdeb5 Correct twin channel operation.
1998-09-21 16:46:13 +00:00

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/*
* Adaptec 274x/284x/294x device driver firmware for Linux and FreeBSD.
*
* Copyright (c) 1994-1998 Justin Gibbs.
* 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, immediately at the beginning of the file.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Where this Software is combined with software released under the terms of
* the GNU Public License (GPL) and the terms of the GPL would require the
* combined work to also be released under the terms of the GPL, the terms
* and conditions of this License will apply in addition to those of the
* GPL with the exception of any terms or conditions of this License that
* conflict with, or are expressly prohibited by, the GPL.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, 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 DAMAGE.
*
* $Id: aic7xxx.seq,v 1.78 1998/09/15 07:24:16 gibbs Exp $
*/
#include <dev/aic7xxx/aic7xxx.reg>
#include <cam/scsi/scsi_message.h>
/*
* 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 psuedo-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.
*/
reset:
clr SCSISIGO; /* De-assert BSY */
/* Always allow reselection */
if ((ahc->flags & AHC_TARGETMODE) != 0) {
mvi SCSISEQ, ENSELI|ENRSELI|ENAUTOATNP;
} else {
mvi SCSISEQ, ENRSELI|ENAUTOATNP;
}
if ((ahc->features & AHC_CMD_CHAN) != 0) {
/* Ensure that no DMA operations are in progress */
clr CCSGCTL;
clr CCSCBCTL;
}
call clear_target_state;
poll_for_work:
and SXFRCTL0, ~SPIOEN;
if ((ahc->features & AHC_QUEUE_REGS) == 0) {
mov A, QINPOS;
}
poll_for_work_loop:
if ((ahc->features & AHC_QUEUE_REGS) == 0) {
and SEQCTL, ~PAUSEDIS;
}
test SSTAT0, SELDO|SELDI jnz selection;
test SCSISEQ, ENSELO jnz poll_for_work;
if ((ahc->features & AHC_TWIN) != 0) {
/*
* Twin channel devices cannot handle things like SELTO
* interrupts on the "background" channel. So, if we
* are selecting, keep polling the current channel util
* either a selection or reselection occurs.
*/
xor SBLKCTL,SELBUSB; /* Toggle to the other bus */
test SSTAT0, SELDO|SELDI jnz selection;
test SCSISEQ, ENSELO jnz poll_for_work;
xor SBLKCTL,SELBUSB; /* Toggle back */
}
cmp WAITING_SCBH,SCB_LIST_NULL jne start_waiting;
test_queue:
/* Has the driver posted any work for us? */
if ((ahc->features & AHC_QUEUE_REGS) != 0) {
test QOFF_CTLSTA, SCB_AVAIL jz poll_for_work_loop;
mov NONE, SNSCB_QOFF;
inc QINPOS;
} else {
or SEQCTL, PAUSEDIS;
cmp KERNEL_QINPOS, A je poll_for_work_loop;
inc QINPOS;
and SEQCTL, ~PAUSEDIS;
}
/*
* We have at least one queued SCB now and we don't have any
* SCBs in the list of SCBs awaiting selection. If we have
* any SCBs available for use, pull the tag from the QINFIFO
* and get to work on it.
*/
if ((ahc->flags & AHC_PAGESCBS) != 0) {
mov ALLZEROS call get_free_or_disc_scb;
}
dequeue_scb:
add A, -1, QINPOS;
mvi QINFIFO_OFFSET call fetch_byte;
if ((ahc->flags & AHC_PAGESCBS) == 0) {
/* In the non-paging case, the SCBID == hardware SCB index */
mov SCBPTR, RETURN_2;
}
dma_queued_scb:
/*
* DMA the SCB from host ram into the current SCB location.
*/
mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
mov RETURN_2 call dma_scb;
/*
* Preset the residual fields in case we never go through a data phase.
* This isn't done by the host so we can avoid a DMA to clear these
* fields for the normal case of I/O that completes without underrun
* or overrun conditions.
*/
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov SCB_RESID_DCNT, SCB_DATACNT, 3;
} else {
mov SCB_RESID_DCNT[0],SCB_DATACNT[0];
mov SCB_RESID_DCNT[1],SCB_DATACNT[1];
mov SCB_RESID_DCNT[2],SCB_DATACNT[2];
}
mov SCB_RESID_SGCNT, SCB_SGCOUNT;
start_scb:
/*
* Place us on the waiting list in case our selection
* doesn't win during bus arbitration.
*/
mov SCB_NEXT,WAITING_SCBH;
mov WAITING_SCBH, SCBPTR;
start_waiting:
/*
* Pull the first entry off of the waiting SCB list.
*/
mov SCBPTR, WAITING_SCBH;
call start_selection;
jmp poll_for_work;
start_selection:
if ((ahc->features & AHC_TWIN) != 0) {
and SINDEX,~SELBUSB,SBLKCTL;/* Clear channel select bit */
and A,SELBUSB,SCB_TCL; /* Get new channel bit */
or SINDEX,A;
mov SBLKCTL,SINDEX; /* select channel */
}
initialize_scsiid:
if ((ahc->features & AHC_ULTRA2) != 0) {
and A, TID, SCB_TCL; /* Get target ID */
and SCSIID_ULTRA2, OID; /* Clear old target */
or SCSIID_ULTRA2, A;
} else {
and A, TID, SCB_TCL; /* Get target ID */
and SCSIID, OID; /* Clear old target */
or SCSIID, A;
}
if ((ahc->flags & AHC_TARGETMODE) != 0) {
and SINDEX, TARGET_SCB, SCB_CONTROL;
or SCSISEQ, ENSELO|ENAUTOATNO|ENSELI
|ENRSELI|ENAUTOATNP, SINDEX ret ;
} else {
mvi SCSISEQ, ENSELO|ENAUTOATNO|ENRSELI|ENAUTOATNP ret;
}
/*
* Initialize transfer settings and clear the SCSI channel.
* SINDEX should contain any additional bit's the client wants
* set in SXFRCTL0. We also assume that the current SCB is
* a valid SCB for the target we wish to talk to.
*/
initialize_channel:
or SXFRCTL0, CLRSTCNT|CLRCHN, SINDEX;
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;
}
selection:
test SSTAT0,SELDO jnz select_out;
mvi CLRSINT0, CLRSELDI;
select_in:
if ((ahc->flags & AHC_TARGETMODE) != 0) {
test SSTAT0, TARGET jz initiator_reselect;
/*
* We've just been selected. Assert BSY and
* setup the phase for receiving messages
* from the target.
*/
mvi SCSISIGO, P_MESGOUT|BSYO;
/*
* LAST_MSG gives an indication to the host of what
* went wrong should we need to terminate this selection
* before doing real work. Initialize it to SCB_LIST_NULL to
* indicate an improper initiator selection.
*/
mvi LAST_MSG, SCB_LIST_NULL;
/*
* Setup the DMA for sending the identify and
* command information. We keep a count of the
* number of bytes to send to the host in ARG_2.
*/
or SEQ_FLAGS, CMDPHASE_PENDING;
mov A, TMODE_CMDADDR_NEXT;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mvi DINDEX, CCHADDR;
mvi TMODE_CMDADDR call set_32byte_addr;
mvi CCSCBCTL, CCSCBRESET;
} else {
mvi DINDEX, HADDR;
mvi TMODE_CMDADDR call set_32byte_addr;
mvi DFCNTRL, FIFORESET;
}
/* Initiator that selected us */
and SAVED_TCL, SELID_MASK, SELID;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, SAVED_TCL;
} else {
mov DFDAT, SAVED_TCL;
}
/* The Target ID we were selected at */
if ((ahc->features & AHC_MULTI_TID) != 0) {
if ((ahc->features & AHC_CMD_CHAN) != 0) {
and CCSCBRAM, 0x0f, TARGIDIN;
} else {
and DFDAT, 0x0f, TARGIDIN;
}
} else {
if ((ahc->features & AHC_CMD_CHAN) != 0) {
and CCSCBRAM, OID, SCSIID;
} else {
and DFDAT, OID, SCSIID;
}
}
/*
* If ATN isn't asserted, the target isn't interested
* in talking to us. Go directly to bus free.
*/
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 targ_inb;
/*
* Our first message must be one of IDENTIFY, ABORT, or
* BUS_DEVICE_RESET.
*/
test DINDEX, MSG_IDENTIFYFLAG jz more_first_messages;
/* Store for host */
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, DINDEX;
} else {
mov DFDAT, DINDEX;
}
mvi ARG_2, 3;
/* 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 targ_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;
add A, -MSG_IGN_WIDE_RESIDUE, DINDEX;
jc ident_messages_done;
/* 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 targ_inb;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, DINDEX;
} else {
mov DFDAT, DINDEX;
}
add ARG_2, 2;
jmp ident_messages_done;
more_first_messages:
/*
* Hmm. Now we're down to only accepting
* either an ABORT or BDR.
*/
cmp DINDEX, MSG_ABORT je . + 2;
cmp DINDEX, MSG_BUS_DEV_RESET jne target_busfree;
/* Record the event and notify the host */
mov LAST_MSG, DINDEX;
jmp target_busfree;
ident_messages_done:
mvi LAST_MSG, MSG_NOOP; /* We are so far successful */
/* 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;
jmp target_ITloop;
/*
* 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.
*/
targ_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;
mov DINDEX, SCSIDATL ret;
}
/*
* 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 */
and SAVED_TCL, SELID_MASK, SELID;
if ((ahc->features & AHC_TWIN) != 0) {
test SBLKCTL, SELBUSB jz . + 2;
or SAVED_TCL, SELBUSB;
}
or SXFRCTL0, SPIOEN|CLRCHN;
mvi CLRSINT1,CLRBUSFREE;
or SIMODE1, ENBUSFREE; /*
* We aren't expecting a
* bus free, so interrupt
* the kernel driver if it
* happens.
*/
mvi MSG_OUT, MSG_NOOP; /* No message to send */
jmp ITloop;
/*
* 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 */
if ((ahc->flags & AHC_TARGETMODE) != 0) {
mvi SCSISEQ, ENSELI|ENRSELI|ENAUTOATNP;
} else {
mvi SCSISEQ, ENRSELI|ENAUTOATNP;
}
mvi CLRSINT0, CLRSELDO;
mov SCBPTR, WAITING_SCBH;
mov WAITING_SCBH,SCB_NEXT;
mov SAVED_TCL, SCB_TCL;
if ((ahc->flags & AHC_TARGETMODE) != 0) {
test SSTAT0, TARGET jz initiator_select;
/*
* We've just re-selected an initiator.
* Assert BSY and setup the phase for
* sending our identify messages.
*/
mvi SCSISIGO, P_MESGIN|BSYO;
/*
* Start out with a simple identify message.
*/
and A, LID, SCB_TCL;
or A, 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_TAG call target_outb;
target_synccmd:
/*
* Now determine what phases the host wants us
* to go through.
*/
mov SEQ_FLAGS, SCB_TARGET_PHASES;
target_ITloop:
/*
* XXX Start honoring ATN signals now that
* we properly identified ourself.
*/
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;
if ((ahc->flags & AHC_PAGESCBS) != 0) {
mov ALLZEROS call get_free_or_disc_scb;
}
call complete_target_cmd;
mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
mov SCB_TAG call dma_scb;
jmp target_synccmd;
target_disconnect:
mvi SCSISIGO, P_MESGIN|BSYO;
mvi MSG_DISCONNECT call target_outb;
target_busfree:
and SXFRCTL0, ~SPIOEN;
clr SCSISIGO;
call complete_target_cmd;
cmp LAST_MSG, MSG_NOOP je . + 2;
mvi INTSTAT, TARGET_MSG_HELP;
call clear_target_state;
jmp poll_for_work;
target_cmdphase:
/*
* Add one for the terminating byte
* and one for the command code.
*/
if ((ahc->features & AHC_CMD_CHAN) != 0) {
add CCHCNT, 2, ARG_2;
} else {
add HCNT[0], 2, ARG_2;
clr HCNT[1];
clr HCNT[2];
}
mvi SCSISIGO, P_COMMAND|BSYO;
call targ_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 using an adding
* jump table. Count is one less than the total
* since we've already fetched the first byte.
*/
shr A, CMD_GROUP_CODE_SHIFT;
add SINDEX, TARG_SCSIRATE, A;
mov A, SINDIR;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
add CCHCNT, A;
} else {
add HCNT[0], A;
}
test A, 0xFF jz command_phase_done;
command_loop:
or SXFRCTL0, SPIOEN;
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 direction flags are from the
* perspective of the initiator.
*/
and SXFRCTL0, ~SPIOEN;
or SXFRCTL0, CLRCHN;
test SCB_TARGET_PHASES[1], TARGET_DATA_IN jz . + 4;
mvi SCSISIGO, P_DATAIN|BSYO;
mvi LASTPHASE, P_DATAOUT;
jmp p_data;
mvi SCSISIGO, P_DATAOUT|BSYO;
mvi LASTPHASE, P_DATAIN;
jmp p_data;
target_sphase:
mvi SCSISIGO, P_STATUS|BSYO;
mov SCB_TARGET_STATUS call target_outb;
/* XXX Watch for ATN for 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;
complete_target_cmd:
test SEQ_FLAGS, TARG_CMD_PENDING jnz . + 2;
mov SCB_TAG jmp complete_post;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
or CCSCBCTL, CCSCBEN|CCSCBRESET;
test CCSCBCTL, CCSCBDONE jz .;
clr CCSCBCTL;
} else {
or DFCNTRL, HDMAEN|FIFOFLUSH;
call dma_finish;
}
inc TMODE_CMDADDR_NEXT;
cmp TMODE_CMDADDR_NEXT, TMODE_NUMCMDS jne . + 2;
clr TMODE_CMDADDR_NEXT;
mvi TARGET_CMD_CMPLT jmp complete_post;
}
initiator_select:
mvi SPIOEN call initialize_channel;
/*
* We aren't expecting a bus free, so interrupt
* the kernel driver if it happens.
*/
mvi CLRSINT1,CLRBUSFREE;
or SIMODE1, ENBUSFREE;
/*
* 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;
or SEQ_FLAGS, IDENTIFY_SEEN;
/*
* 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.
*/
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 INTSTAT,BAD_PHASE; /* unknown phase - signal driver */
jmp ITloop; /* Try reading the bus again. */
await_busfree:
and SIMODE1, ~ENBUSFREE;
call clear_target_state;
mov NONE, SCSIDATL; /* Ack the last byte */
and SXFRCTL0, ~SPIOEN;
test SSTAT1,REQINIT|BUSFREE jz .;
test SSTAT1, BUSFREE jnz poll_for_work;
mvi INTSTAT, BAD_PHASE;
clear_target_state:
clr DFCNTRL; /*
* We assume that the kernel driver
* may reset us at any time, even
* in the middle of a DMA, so clear
* DFCNTRL too.
*/
clr SCSIRATE; /*
* We don't know the target we will
* connect to, so default to narrow
* transfers to avoid parity problems.
*/
and SXFRCTL0, ~(FAST20);
mvi LASTPHASE, P_BUSFREE;
/* clear target specific flags */
clr SEQ_FLAGS ret;
/*
* If we re-enter the data phase after going through another phase, the
* STCNT may have been cleared, so restore it from the residual field.
*/
data_phase_reinit:
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov STCNT, SCB_RESID_DCNT, 3;
} else {
mvi DINDEX, STCNT;
mvi SCB_RESID_DCNT call bcopy_3;
}
jmp data_phase_loop;
p_data:
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;
call assert; /*
* Ensure entering a data
* phase is okay - seen identify, etc.
*/
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mvi CCSGADDR, CCSGADDR_MAX;
}
test SEQ_FLAGS, DPHASE jnz data_phase_reinit;
/* We have seen a data phase */
or SEQ_FLAGS, DPHASE;
/*
* Initialize the DMA address and counter from the SCB.
* Also set SG_COUNT and SG_NEXT in memory since we cannot
* modify the values in the SCB itself until we see a
* save data pointers message.
*/
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov HADDR, SCB_DATAPTR, 7;
} else {
mvi DINDEX, HADDR;
mvi SCB_DATAPTR call bcopy_7;
}
if ((ahc->features & AHC_ULTRA2) == 0) {
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov STCNT, HCNT, 3;
} else {
call set_stcnt_from_hcnt;
}
}
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov SG_COUNT, SCB_SGCOUNT, 5;
} else {
mvi DINDEX, SG_COUNT;
mvi SCB_SGCOUNT call bcopy_5;
}
data_phase_loop:
/* Guard against overruns */
test SG_COUNT, 0xff jnz data_phase_inbounds;
/*
* Turn on 'Bit Bucket' mode, set the transfer count to
* 16meg and let the target run until it changes phase.
* When the transfer completes, notify the host that we
* had an overrun.
*/
or SXFRCTL1,BITBUCKET;
and DMAPARAMS, ~(HDMAEN|SDMAEN);
if ((ahc->features & AHC_ULTRA2) != 0) {
bmov HCNT, ALLONES, 3;
} else if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov STCNT, ALLONES, 3;
} else {
mvi STCNT[0], 0xFF;
mvi STCNT[1], 0xFF;
mvi STCNT[2], 0xFF;
}
data_phase_inbounds:
/* If we are the last SG block, tell the hardware. */
cmp SG_COUNT,0x01 jne data_phase_wideodd;
if ((ahc->features & AHC_ULTRA2) != 0) {
or SG_CACHEPTR, LAST_SEG;
} else {
and DMAPARAMS, ~WIDEODD;
}
data_phase_wideodd:
if ((ahc->features & AHC_ULTRA2) != 0) {
mov SINDEX, ALLONES;
mov DFCNTRL, DMAPARAMS;
test SSTAT0, SDONE jnz .;/* Wait for preload to complete */
data_phase_dma_loop:
test SSTAT0, SDONE jnz data_phase_dma_done;
test SSTAT1,PHASEMIS jz data_phase_dma_loop; /* ie. underrun */
data_phase_dma_phasemis:
test SSTAT0,SDONE jnz . + 2;
mov SINDEX,ALLZEROS; /* Remeber the phasemiss */
} else {
mov DMAPARAMS call dma;
}
data_phase_dma_done:
/* Go tell the host about any overruns */
test SXFRCTL1,BITBUCKET jnz data_phase_overrun;
/* Exit if we had an underrun. dma clears SINDEX in this case. */
test SINDEX,0xff jz data_phase_finish;
/*
* Advance the scatter-gather pointers if needed
*/
sg_advance:
dec SG_COUNT; /* one less segment to go */
test SG_COUNT, 0xff jz data_phase_finish; /* Are we done? */
/*
* Load a struct scatter and set up the data address and length.
* If the working value of the SG count is nonzero, then
* we need to load a new set of values.
*
* This, like all DMA's, assumes little-endian host data storage.
*/
sg_load:
if ((ahc->features & AHC_CMD_CHAN) != 0) {
/*
* Do we have any prefetch left???
*/
cmp CCSGADDR, CCSGADDR_MAX jne prefetched_segs_avail;
/*
* Fetch MIN(CCSGADDR_MAX, (SG_COUNT * 8)) bytes.
*/
add A, -(CCSGRAM_MAXSEGS + 1), SG_COUNT;
mvi A, CCSGADDR_MAX;
jc . + 2;
shl A, 3, SG_COUNT;
mov CCHCNT, A;
bmov CCHADDR, SG_NEXT, 4;
mvi CCSGCTL, CCSGEN|CCSGRESET;
test CCSGCTL, CCSGDONE jz .;
and CCSGCTL, ~CCSGEN;
test CCSGCTL, CCSGEN jnz .;
mvi CCSGCTL, CCSGRESET;
prefetched_segs_avail:
bmov HADDR, CCSGRAM, 8;
} else {
mvi DINDEX, HADDR;
mvi SG_NEXT call bcopy_4;
mvi HCNT[0],SG_SIZEOF;
clr HCNT[1];
clr HCNT[2];
or DFCNTRL, HDMAEN|DIRECTION|FIFORESET;
call dma_finish;
/*
* Copy data from FIFO into SCB data pointer and data count.
* This assumes that the SG segments are of the form:
* struct ahc_dma_seg {
* u_int32_t addr; four bytes, little-endian order
* u_int32_t len; four bytes, little endian order
* };
*/
mvi HADDR call dfdat_in_7;
}
if ((ahc->features & AHC_ULTRA2) == 0) {
/* Load STCNT as well. It is a mirror of HCNT */
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov STCNT, HCNT, 3;
} else {
call set_stcnt_from_hcnt;
}
}
/* Advance the SG pointer */
clr A; /* add sizeof(struct scatter) */
add SG_NEXT[0],SG_SIZEOF;
adc SG_NEXT[1],A;
test SSTAT1,PHASEMIS jz data_phase_loop;
/* Ensure the last seg is visable at the shaddow layer */
if ((ahc->features & AHC_ULTRA2) != 0) {
or DFCNTRL, PRELOADEN;
}
data_phase_finish:
if ((ahc->features & AHC_ULTRA2) != 0) {
call ultra2_dmafinish;
}
/*
* 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) {
bmov SCB_RESID_DCNT, STCNT, 3;
} else {
mov SCB_RESID_DCNT[0],STCNT[0];
mov SCB_RESID_DCNT[1],STCNT[1];
mov SCB_RESID_DCNT[2],STCNT[2];
}
mov SCB_RESID_SGCNT, SG_COUNT;
if ((ahc->features & AHC_ULTRA2) != 0) {
or SXFRCTL0, CLRSTCNT|CLRCHN;
}
if ((ahc->flags & AHC_TARGETMODE) != 0) {
test SEQ_FLAGS, DPHASE_PENDING jz . + 3;
and SEQ_FLAGS, ~DPHASE_PENDING;
jmp target_ITloop;
}
jmp ITloop;
data_phase_overrun:
if ((ahc->features & AHC_ULTRA2) != 0) {
call ultra2_dmafinish;
or SXFRCTL0, CLRSTCNT|CLRCHN;
}
/*
* Turn off BITBUCKET mode and notify the host
*/
and SXFRCTL1, ~BITBUCKET;
mvi INTSTAT,DATA_OVERRUN;
jmp ITloop;
ultra2_dmafinish:
if ((ahc->features & AHC_ULTRA2) != 0) {
test DFCNTRL, DIRECTION jnz ultra2_dmahalt;
and DFCNTRL, ~SCSIEN;
test DFCNTRL, SCSIEN jnz .;
or DFCNTRL, FIFOFLUSH;
test DFSTATUS, FIFOEMP jz . - 1;
ultra2_dmahalt:
and DFCNTRL, ~(SCSIEN|HDMAEN);
test DFCNTRL, HDMAEN jnz .;
ret;
}
/*
* Command phase. Set up the DMA registers and let 'er rip.
*/
p_command:
call assert;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov HCNT[0], SCB_CMDLEN;
bmov HCNT[1], ALLZEROS, 2;
if ((ahc->features & AHC_ULTRA2) == 0) {
bmov STCNT, HCNT, 3;
}
add NONE, -17, SCB_CMDLEN;
jc dma_cmd_data;
if ((ahc->features & AHC_ULTRA2) != 0) {
mvi DFCNTRL, (PRELOADEN|SCSIEN|DIRECTION);
} else {
mvi DFCNTRL, (SCSIEN|SDMAEN|DIRECTION|FIFORESET);
}
bmov DFDAT, SCB_CMDSTORE, 16;
jmp cmd_loop;
dma_cmd_data:
bmov HADDR, SCB_CMDPTR, 4;
} else {
mvi DINDEX, HADDR;
mvi SCB_CMDPTR call bcopy_5;
clr HCNT[1];
clr HCNT[2];
}
if ((ahc->features & AHC_ULTRA2) == 0) {
if ((ahc->features & AHC_CMD_CHAN) == 0) {
call set_stcnt_from_hcnt;
}
mvi DFCNTRL, (SCSIEN|SDMAEN|HDMAEN|DIRECTION|FIFORESET);
} else {
mvi DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN|DIRECTION);
}
cmd_loop:
test SSTAT0, SDONE jnz . + 2;
test SSTAT1, PHASEMIS jz cmd_loop;
and DFCNTRL, ~(SCSIEN|HDMAEN|SDMAEN);
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:
call assert;
mov SCB_TARGET_STATUS, SCSIDATL;
jmp ITloop;
/*
* Message out phase. If MSG_OUT is 0x80, build I full indentify message
* sequence and send it to the target. In addition, if the MK_MESSAGE bit
* is set in the SCB_CONTROL byte, interrupt the host and allow it to send
* it's own message.
*
* If MSG_OUT is == HOST_MSG, also interrupt the host and take a message.
* This is done to allow the hsot to send messages outside of an identify
* sequence while protecting the seqencer from testing the MK_MESSAGE bit
* on an SCB that might not be for the current nexus. (For example, a
* BDR message in responce 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:
mov SINDEX, MSG_OUT;
cmp SINDEX, MSG_IDENTIFYFLAG jne p_mesgout_from_host;
p_mesgout_identify:
if ((ahc->features & AHC_WIDE) != 0) {
and SINDEX,0xf,SCB_TCL; /* lun */
} else {
and SINDEX,0x7,SCB_TCL; /* lun */
}
and A,DISCENB,SCB_CONTROL; /* mask off disconnect privledge */
or SINDEX,A; /* or in disconnect privledge */
or SINDEX,MSG_IDENTIFYFLAG;
p_mesgout_mk_message:
test SCB_CONTROL,MK_MESSAGE jz p_mesgout_tag;
mov SCSIDATL, SINDEX; /* Send the last byte */
jmp p_mesgout_from_host + 1;/* Skip HOST_MSG test */
/*
* 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 send a message
* if it asks.
*/
p_mesgout_from_host:
cmp SINDEX, HOST_MSG jne p_mesgout_onebyte;
mvi INTSTAT,AWAITING_MSG;
nop;
/*
* Did the host detect a phase change?
*/
cmp RETURN_1, MSGOUT_PHASEMIS je p_mesgout_done;
p_mesgout_onebyte:
mvi CLRSINT1, CLRATNO;
mov SCSIDATL, SINDEX;
/*
* If the next bus phase after ATN drops is a message out, it means
* that the target is requesting that the last message(s) be resent.
*/
call phase_lock;
cmp LASTPHASE, P_MESGOUT jne p_mesgout_done;
or SCSISIGO,ATNO,LASTPHASE;/* turn on ATN for the retry */
jmp p_mesgout;
p_mesgout_done:
mvi CLRSINT1,CLRATNO; /* Be sure to turn ATNO off */
mov LAST_MSG, MSG_OUT;
cmp MSG_OUT, MSG_IDENTIFYFLAG jne . + 2;
and SCB_CONTROL, ~MK_MESSAGE;
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_EXTENDED je mesgin_extended;
cmp A,MSG_MESSAGE_REJECT je mesgin_reject;
cmp A,MSG_NOOP je mesgin_done;
rej_mesgin:
/*
* We have no idea what this message in is, so we issue a message reject
* and hope for the best. In any case, rejection should be a rare
* occurrence - signal the driver when it happens.
*/
mvi INTSTAT,SEND_REJECT; /* let driver know */
mvi MSG_MESSAGE_REJECT call mk_mesg;
mesgin_done:
mov NONE,SCSIDATL; /*dummy read from latch to ACK*/
jmp ITloop;
mesgin_complete:
/*
* We got a "command complete" message, so put the SCB_TAG into the QOUTFIFO,
* and trigger a completion interrupt. Before doing so, check to see if there
* is a residual or the status byte is something other than STATUS_GOOD (0).
* In either of these conditions, we upload the SCB back to the host so it can
* process this information. In the case of a non zero status byte, we
* additionally interrupt the kernel driver synchronously, allowing it to
* decide if sense should be retrieved. If the kernel driver wishes to request
* sense, it will fill the kernel SCB with a request sense command and set
* RETURN_1 to SEND_SENSE. If RETURN_1 is set to SEND_SENSE we redownload
* the SCB, and process it as the next command by adding it to the waiting list.
* If the kernel driver does not wish to request sense, it need only clear
* RETURN_1, and the command is allowed to complete normally. We don't bother
* to post to the QOUTFIFO in the error cases since it would require extra
* work in the kernel driver to ensure that the entry was removed before the
* command complete code tried processing it.
*/
/*
* First check for residuals
*/
test SCB_RESID_SGCNT,0xff jnz upload_scb;
test SCB_TARGET_STATUS,0xff jz complete; /* Good Status? */
upload_scb:
mvi DMAPARAMS, FIFORESET;
mov SCB_TAG call dma_scb;
check_status:
test SCB_TARGET_STATUS,0xff jz complete; /* Just a residual? */
mvi INTSTAT,BAD_STATUS; /* let driver know */
nop;
cmp RETURN_1, SEND_SENSE jne complete;
/* This SCB becomes the next to execute as it will retrieve sense */
mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
mov SCB_TAG call dma_scb;
add_to_waiting_list:
mov SCB_NEXT,WAITING_SCBH;
mov WAITING_SCBH, SCBPTR;
/*
* Prepare our selection hardware before the busfree so we have a
* high probability of winning arbitration.
*/
call start_selection;
jmp await_busfree;
complete:
/* If we are untagged, clear our address up in host ram */
test SCB_CONTROL, TAG_ENB jnz complete_queue;
mov A, SAVED_TCL;
mvi UNTAGGEDSCB_OFFSET call post_byte_setup;
mvi SCB_LIST_NULL call post_byte;
complete_queue:
mov SCB_TAG call complete_post;
add_to_free_list:
call add_scb_to_free_list;
jmp await_busfree;
complete_post:
/* Post the SCBID in SINDEX and issue an interrupt */
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;
}
if ((ahc->flags & AHC_TARGETMODE) != 0) {
test SEQ_FLAGS, NO_DISCONNECT jz . + 3;
mvi INTSTAT,TARGET_SYNC_CMD|CMDCMPLT;
ret;
}
mvi INTSTAT,CMDCMPLT ret;
/*
* Is it an extended message? Copy the message to our message buffer and
* notify the host. The host will tell us whether to reject this message,
* respond to it with the message that the host placed in our message buffer,
* or simply to do nothing.
*/
mesgin_extended:
mvi INTSTAT,EXTENDED_MSG; /* let driver know */
jmp ITloop;
/*
* Is it a disconnect message? Set a flag in the SCB to remind us
* and await the bus going free.
*/
mesgin_disconnect:
or SCB_CONTROL,DISCONNECTED;
call add_scb_to_disc_list;
jmp await_busfree;
/*
* Save data pointers message:
* Copying RAM values back to SCB, for Save Data Pointers message, but
* only if we've actually been into a data phase to change them. This
* protects against bogus data in scratch ram and the residual counts
* since they are only initialized when we go into data_in or data_out.
*/
mesgin_sdptrs:
test SEQ_FLAGS, DPHASE jz mesgin_done;
/*
* The SCB SGPTR becomes the next one we'll download,
* and the SCB DATAPTR becomes the current SHADDR.
* Use the residual number since STCNT is corrupted by
* any message transfer.
*/
if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov SCB_SGCOUNT, SG_COUNT, 5;
bmov SCB_DATAPTR, SHADDR, 4;
bmov SCB_DATACNT, SCB_RESID_DCNT, 3;
} else {
mvi DINDEX, SCB_SGCOUNT;
mvi SG_COUNT call bcopy_5;
mvi DINDEX, SCB_DATAPTR;
mvi SHADDR call bcopy_4;
mvi SCB_RESID_DCNT call bcopy_3;
}
jmp mesgin_done;
/*
* Restore pointers message? Data pointers are recopied from the
* SCB anytime we enter a data phase for the first time, so all
* we need to do is clear the DPHASE flag and let the data phase
* code do the rest.
*/
mesgin_rdptrs:
and SEQ_FLAGS, ~DPHASE; /*
* We'll reload them
* the next time through
* the dataphase.
*/
jmp mesgin_done;
/*
* Identify message? For a reconnecting target, this tells us the lun
* that the reconnection is for - find the correct SCB and switch to it,
* clearing the "disconnected" bit so we don't "find" it by accident later.
*/
mesgin_identify:
if ((ahc->features & AHC_WIDE) != 0) {
and A,0x0f; /* lun in lower four bits */
} else {
and A,0x07; /* lun in lower three bits */
}
or SAVED_TCL,A; /* SAVED_TCL should be complete now */
mvi ARG_2, SCB_LIST_NULL; /* SCBID of prev SCB in disc List */
call get_untagged_SCBID;
cmp ARG_1, SCB_LIST_NULL je snoop_tag;
if ((ahc->flags & AHC_PAGESCBS) != 0) {
test SEQ_FLAGS, SCBPTR_VALID jz use_retrieveSCB;
}
/*
* If the SCB was found in the disconnected list (as is
* always the case in non-paging scenarios), SCBPTR is already
* set to the correct SCB. So, simply setup the SCB and get
* on with things.
*/
call rem_scb_from_disc_list;
jmp setup_SCB;
/*
* Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message.
* If we get one, we use the tag returned to find the proper
* SCB. With SCB paging, this requires using search for both tagged
* and non-tagged transactions since the SCB may exist in any slot.
* If we're not using SCB paging, we can use the tag as the direct
* index to the SCB.
*/
snoop_tag:
mov NONE,SCSIDATL; /* ACK Identify MSG */
snoop_tag_loop:
call phase_lock;
cmp LASTPHASE, P_MESGIN jne not_found;
cmp SCSIBUSL,MSG_SIMPLE_Q_TAG jne not_found;
get_tag:
mvi ARG_1 call inb_next; /* tag value */
/*
* Ensure that the SCB the tag points to is for
* an SCB transaction to the reconnecting target.
*/
use_retrieveSCB:
call retrieveSCB;
setup_SCB:
mov A, SAVED_TCL;
cmp SCB_TCL, A jne not_found_cleanup_scb;
test SCB_CONTROL,DISCONNECTED jz not_found_cleanup_scb;
and SCB_CONTROL,~DISCONNECTED;
or SEQ_FLAGS,IDENTIFY_SEEN; /* make note of IDENTIFY */
call set_transfer_settings;
/* See if the host wants to send a message upon reconnection */
test SCB_CONTROL, MK_MESSAGE jz mesgin_done;
and SCB_CONTROL, ~MK_MESSAGE;
mvi HOST_MSG call mk_mesg;
jmp mesgin_done;
not_found_cleanup_scb:
test SCB_CONTROL, DISCONNECTED jz . + 3;
call add_scb_to_disc_list;
jmp not_found;
call add_scb_to_free_list;
not_found:
mvi INTSTAT, NO_MATCH;
mvi MSG_BUS_DEV_RESET call mk_mesg;
jmp mesgin_done;
/*
* Message reject? Let the kernel driver handle this. If we have an
* outstanding WDTR or SDTR negotiation, assume that it's a response from
* the target selecting 8bit or asynchronous transfer, otherwise just ignore
* it since we have no clue what it pertains to.
*/
mesgin_reject:
mvi INTSTAT, REJECT_MSG;
jmp mesgin_done;
/*
* [ ADD MORE MESSAGE HANDLING HERE ]
*/
/*
* Locking the driver out, build a one-byte message passed in SINDEX
* if there is no active message already. SINDEX is returned intact.
*/
mk_mesg:
or SCSISIGO,ATNO,LASTPHASE;/* turn on ATNO */
mov MSG_OUT,SINDEX ret;
/*
* Functions to read data in Automatic PIO mode.
*
* According to Adaptec's documentation, an ACK is not sent on input from
* the target until SCSIDATL is read from. So we wait until SCSIDATL is
* latched (the usual way), then read the data byte directly off the bus
* using SCSIBUSL. When we have pulled the ATN line, or we just want to
* acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI
* spec guarantees that the target will hold the data byte on the bus until
* we send our ACK.
*
* The assumption here is that these are called in a particular sequence,
* and that REQ is already set when inb_first is called. inb_{first,next}
* use the same calling convention as inb.
*/
inb_next:
mov NONE,SCSIDATL; /*dummy read from latch to ACK*/
inb_next_wait:
/*
* If there is a parity error, wait for the kernel to
* see the interrupt and prepare our message response
* before continuing.
*/
test SSTAT1, REQINIT jz inb_next_wait;
test SSTAT1, SCSIPERR jnz inb_next_wait;
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_TARGETMODE) != 0) {
/*
* Send a byte to an initiator in Automatic PIO mode.
* SPIOEN must be on prior to calling this routine.
*/
target_outb:
or SXFRCTL0, SPIOEN;
test SSTAT0, SPIORDY jz .;
mov SCSIDATL, SINDEX;
test SSTAT0, SPIORDY jz .;
ret;
}
mesgin_phasemis:
/*
* We expected to receive another byte, but the target changed phase
*/
mvi INTSTAT, MSGIN_PHASEMIS;
jmp ITloop;
/*
* DMA data transfer. HADDR and HCNT must be loaded first, and
* SINDEX should contain the value to load DFCNTRL with - 0x3d for
* host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared
* during initialization.
*/
dma:
mov DFCNTRL,SINDEX;
dma_loop:
test SSTAT0,DMADONE jnz dma_dmadone;
test SSTAT1,PHASEMIS jz dma_loop; /* ie. underrun */
dma_phasemis:
test SSTAT0,SDONE jnz dma_checkfifo;
mov SINDEX,ALLZEROS; /* Notify caller of phasemiss */
/*
* We will be "done" DMAing when the transfer count goes to zero, or
* the target changes the phase (in light of this, it makes sense that
* the DMA circuitry doesn't ACK when PHASEMIS is active). If we are
* doing a SCSI->Host transfer, the data FIFO should be flushed auto-
* magically on STCNT=0 or a phase change, so just wait for FIFO empty
* status.
*/
dma_checkfifo:
test DFCNTRL,DIRECTION jnz dma_fifoempty;
dma_fifoflush:
test DFSTATUS,FIFOEMP jz dma_fifoflush;
dma_fifoempty:
/* Don't clobber an inprogress host data transfer */
test DFSTATUS, MREQPEND jnz dma_fifoempty;
/*
* Now shut the DMA enables off and make sure that the DMA enables are
* actually off first lest we get an ILLSADDR.
*/
dma_dmadone:
and DFCNTRL, ~(SCSIEN|SDMAEN|HDMAEN);
dma_halt:
/*
* Some revisions of the aic7880 have a problem where, if the
* data fifo is full, but the PCI input latch is not empty,
* HDMAEN cannot be cleared. The fix used here is to attempt
* to drain the data fifo until there is space for the input
* latch to drain and HDMAEN de-asserts.
*/
if ((ahc->features & AHC_ULTRA2) == 0) {
mov NONE, DFDAT;
}
test DFCNTRL, (SCSIEN|SDMAEN|HDMAEN) jnz dma_halt;
return:
ret;
/*
* Assert that if we've been reselected, then we've seen an IDENTIFY
* message.
*/
assert:
test SEQ_FLAGS,IDENTIFY_SEEN jnz return; /* seen IDENTIFY? */
mvi INTSTAT,NO_IDENT ret; /* no - tell the kernel */
/*
* Locate a disconnected SCB either by SAVED_TCL (ARG_1 is SCB_LIST_NULL)
* or by the SCBID ARG_1. The search begins at the SCB index passed in
* via SINDEX which is an SCB that must be on the disconnected list. If
* the SCB cannot be found, SINDEX will be SCB_LIST_NULL, otherwise, SCBPTR
* is set to the proper SCB.
*/
findSCB:
mov SCBPTR,SINDEX; /* Initialize SCBPTR */
cmp ARG_1, SCB_LIST_NULL jne findSCB_by_SCBID;
mov A, SAVED_TCL;
mvi SCB_TCL jmp findSCB_loop; /* &SCB_TCL -> SINDEX */
findSCB_by_SCBID:
mov A, ARG_1; /* Tag passed in ARG_1 */
mvi SCB_TAG jmp findSCB_loop; /* &SCB_TAG -> SINDEX */
findSCB_next:
mov ARG_2, SCBPTR;
cmp SCB_NEXT, SCB_LIST_NULL je notFound;
mov SCBPTR,SCB_NEXT;
dec SINDEX; /* Last comparison moved us too far */
findSCB_loop:
cmp SINDIR, A jne findSCB_next;
mov SINDEX, SCBPTR ret;
notFound:
mvi SINDEX, SCB_LIST_NULL ret;
/*
* Retrieve an SCB by SCBID first searching the disconnected list falling
* back to DMA'ing the SCB down from the host. This routine assumes that
* ARG_1 is the SCBID of interrest and that SINDEX is the position in the
* disconnected list to start the search from. If SINDEX is SCB_LIST_NULL,
* we go directly to the host for the SCB.
*/
retrieveSCB:
test SEQ_FLAGS, SCBPTR_VALID jz retrieve_from_host;
mov SCBPTR call findSCB; /* Continue the search */
cmp SINDEX, SCB_LIST_NULL je retrieve_from_host;
/*
* This routine expects SINDEX to contain the index of the SCB to be
* removed, SCBPTR to be pointing to that SCB, and ARG_2 to be the
* SCBID of the SCB just previous to this one in the list or SCB_LIST_NULL
* if it is at the head.
*/
rem_scb_from_disc_list:
/* Remove this SCB from the disconnection list */
cmp ARG_2, SCB_LIST_NULL je rHead;
mov DINDEX, SCB_NEXT;
mov SCBPTR, ARG_2;
mov SCB_NEXT, DINDEX;
mov SCBPTR, SINDEX ret;
rHead:
mov DISCONNECTED_SCBH,SCB_NEXT ret;
retrieve_from_host:
/*
* We didn't find it. Pull an SCB and DMA down the one we want.
* We should never get here in the non-paging case.
*/
mov ALLZEROS call get_free_or_disc_scb;
mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
/* Jump instead of call as we want to return anyway */
mov ARG_1 jmp dma_scb;
/*
* Determine whether a target is using tagged or non-tagged transactions
* by first looking for a matching transaction based on the TCL and if
* that fails, looking up this device in the host's untagged SCB array.
* The TCL to search for is assumed to be in SAVED_TCL. The value is
* returned in ARG_1 (SCB_LIST_NULL for tagged, SCBID for non-tagged).
* The SCBPTR_VALID bit is set in SEQ_FLAGS if we found the information
* in an SCB instead of having to go to the host.
*/
get_untagged_SCBID:
cmp DISCONNECTED_SCBH, SCB_LIST_NULL je get_SCBID_from_host;
mvi ARG_1, SCB_LIST_NULL;
mov DISCONNECTED_SCBH call findSCB;
cmp SINDEX, SCB_LIST_NULL je get_SCBID_from_host;
or SEQ_FLAGS, SCBPTR_VALID;/* Was in disconnected list */
test SCB_CONTROL, TAG_ENB jnz . + 2;
mov ARG_1, SCB_TAG ret;
mvi ARG_1, SCB_LIST_NULL ret;
/*
* Fetch a byte from host memory given an index of (A + (256 * SINDEX))
* and a base address of SCBID_ADDR. The byte is returned in RETURN_2.
*/
fetch_byte:
mov ARG_2, SINDEX;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mvi DINDEX, CCHADDR;
mvi SCBID_ADDR call set_1byte_addr;
mvi CCHCNT, 1;
mvi CCSGCTL, CCSGEN|CCSGRESET;
test CCSGCTL, CCSGDONE jz .;
mvi CCSGCTL, CCSGRESET;
bmov RETURN_2, CCSGRAM, 1 ret;
} else {
mvi DINDEX, HADDR;
mvi SCBID_ADDR call set_1byte_addr;
mvi HCNT[0], 1;
clr HCNT[1];
clr HCNT[2];
mvi DFCNTRL, HDMAEN|DIRECTION|FIFORESET;
call dma_finish;
mov RETURN_2, DFDAT ret;
}
/*
* Prepare the hardware to post a byte to host memory given an
* index of (A + (256 * SINDEX)) and a base address of SCBID_ADDR.
*/
post_byte_setup:
mov ARG_2, SINDEX;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mvi DINDEX, CCHADDR;
mvi SCBID_ADDR call set_1byte_addr;
mvi CCHCNT, 1;
mvi CCSCBCTL, CCSCBRESET ret;
} else {
mvi DINDEX, HADDR;
mvi SCBID_ADDR call set_1byte_addr;
mvi HCNT[0], 1;
clr HCNT[1];
clr HCNT[2];
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;
}
get_SCBID_from_host:
mov A, SAVED_TCL;
mvi UNTAGGEDSCB_OFFSET call fetch_byte;
mov RETURN_1, RETURN_2 ret;
phase_lock:
test SSTAT1, REQINIT jz phase_lock;
test SSTAT1, SCSIPERR jnz phase_lock;
and LASTPHASE, PHASE_MASK, SCSISIGI;
mov SCSISIGO, LASTPHASE ret;
if ((ahc->features & AHC_CMD_CHAN) == 0) {
set_stcnt_from_hcnt:
mov STCNT[0], HCNT[0];
mov STCNT[1], HCNT[1];
mov STCNT[2], HCNT[2] ret;
bcopy_7:
mov DINDIR, SINDIR;
mov DINDIR, SINDIR;
bcopy_5:
mov DINDIR, SINDIR;
bcopy_4:
mov DINDIR, SINDIR;
bcopy_3:
mov DINDIR, SINDIR;
mov DINDIR, SINDIR;
mov DINDIR, SINDIR ret;
}
if ((ahc->flags & AHC_TARGETMODE) != 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_1 * 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 and 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;
mvi CCHCNT, SCB_64BYTE_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_32BYTE_SIZE;
if ((ahc->chip & AHC_CHIPID_MASK) == AHC_AIC7895) {
mvi CCSCBCTL, CCSCBRESET;
bmov CCSCBRAM, SCB_CONTROL, SCB_32BYTE_SIZE;
or CCSCBCTL, CCSCBEN|CCSCBRESET;
test CCSCBCTL, CCSCBDONE jz .;
} 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 HCNT[0], SCB_32BYTE_SIZE;
clr HCNT[1];
clr HCNT[2];
mov DFCNTRL, DMAPARAMS;
test DMAPARAMS, DIRECTION jnz dma_scb_fromhost;
/* Fill it with the SCB data */
copy_scb_tofifo:
mvi SINDEX, SCB_CONTROL;
add A, SCB_32BYTE_SIZE, SINDEX;
copy_scb_tofifo_loop:
mov DFDAT,SINDIR;
mov DFDAT,SINDIR;
mov DFDAT,SINDIR;
mov DFDAT,SINDIR;
mov DFDAT,SINDIR;
mov DFDAT,SINDIR;
mov DFDAT,SINDIR;
cmp SINDEX, A jne copy_scb_tofifo_loop;
or DFCNTRL, HDMAEN|FIFOFLUSH;
dma_scb_fromhost:
call dma_finish;
/* If we were putting the SCB, we are done */
test DMAPARAMS, DIRECTION jz return;
mvi SCB_CONTROL call dfdat_in_7;
call dfdat_in_7_continued;
call dfdat_in_7_continued;
jmp dfdat_in_7_continued;
dfdat_in_7:
mov DINDEX,SINDEX;
dfdat_in_7_continued:
mov DINDIR,DFDAT;
mov DINDIR,DFDAT;
mov DINDIR,DFDAT;
mov DINDIR,DFDAT;
mov DINDIR,DFDAT;
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;
/* Turn off DMA */
and DFCNTRL, ~HDMAEN;
test DFCNTRL, HDMAEN jnz .;
ret;
add_scb_to_free_list:
if ((ahc->flags & AHC_PAGESCBS) != 0) {
mov SCB_NEXT, FREE_SCBH;
mov FREE_SCBH, SCBPTR;
}
mvi SCB_TAG, SCB_LIST_NULL ret;
if ((ahc->flags & AHC_PAGESCBS) != 0) {
get_free_or_disc_scb:
cmp FREE_SCBH, SCB_LIST_NULL jne dequeue_free_scb;
cmp DISCONNECTED_SCBH, SCB_LIST_NULL jne dequeue_disc_scb;
return_error:
mvi SINDEX, SCB_LIST_NULL ret;
dequeue_disc_scb:
mov SCBPTR, DISCONNECTED_SCBH;
dma_up_scb:
mvi DMAPARAMS, FIFORESET;
mov SCB_TAG call dma_scb;
unlink_disc_scb:
mov DISCONNECTED_SCBH, SCB_NEXT ret;
dequeue_free_scb:
mov SCBPTR, FREE_SCBH;
mov FREE_SCBH, SCB_NEXT 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.
*/
mov SCB_NEXT, DISCONNECTED_SCBH;
mov DISCONNECTED_SCBH, SCBPTR ret;
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