freebsd-skq/sys/dev/aic7xxx/aic7xxx.seq
gibbs 8a7720ea1c Work around a defect in the FIFOEMP status bit of Ultra2 class
aic7xxx parts.  This problem could result in data corruption
during periods of my PCI bus load by busmasters other than the
aic7xxx.

Many thanks to Andrew Gallatin <gallatin@cs.duke.edu> for characterizing
the symptoms of this problem and testing this fix.
1999-09-20 18:57:04 +00:00

1838 lines
52 KiB
Plaintext

/*
* Adaptec 274x/284x/294x device driver firmware for Linux and FreeBSD.
*
* Copyright (c) 1994-1999 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.
*
* $FreeBSD$
*/
#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 */
and SXFRCTL1, ~BITBUCKET;
/* Always allow reselection */
and SCSISEQ, ENSELI|ENRSELI|ENAUTOATNP, SCSISEQ_TEMPLATE;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
/* Ensure that no DMA operations are in progress */
clr CCSGCTL;
clr CCSCBCTL;
}
poll_for_work:
call clear_target_state;
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:
mov SINDEX, SCSISEQ_TEMPLATE;
if ((ahc->flags & AHC_TARGETMODE) != 0) {
test SCB_CONTROL, TARGET_SCB jz . + 4;
if ((ahc->features & AHC_ULTRA2) != 0) {
mov SCSIID_ULTRA2, SCB_CMDPTR[2];
} else {
mov SCSIID, SCB_CMDPTR[2];
}
or SINDEX, TEMODE;
jmp initialize_scsiid_fini;
}
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;
}
initialize_scsiid_fini:
mov SCSISEQ, SINDEX 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) {
if ((ahc->flags & AHC_INITIATORMODE) != 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;
mvi CLRSINT1, CLRBUSFREE;
/*
* Setup the DMA for sending the identify and
* command information.
*/
or SEQ_FLAGS, CMDPHASE_PENDING;
mov A, TQINPOS;
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_CMD_CHAN) != 0) {
if ((ahc->features & AHC_MULTI_TID) != 0) {
and CCSCBRAM, OID, TARGIDIN;
} else if ((ahc->features & AHC_ULTRA2) != 0) {
and CCSCBRAM, OID, SCSIID_ULTRA2;
} else {
and CCSCBRAM, OID, SCSIID;
}
} else {
if ((ahc->features & AHC_MULTI_TID) != 0) {
and DFDAT, OID, TARGIDIN;
} else if ((ahc->features & AHC_ULTRA2) != 0) {
and DFDAT, OID, SCSIID_ULTRA2;
} else {
and DFDAT, OID, SCSIID;
}
}
/* No tag yet */
mvi INITIATOR_TAG, SCB_LIST_NULL;
/*
* 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 target_inb;
/*
* Our first message must be one of IDENTIFY, ABORT, or
* BUS_DEVICE_RESET.
*/
/* XXX May need to be more lax here for older initiators... */
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;
}
/* 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;
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 target_inb;
if ((ahc->features & AHC_CMD_CHAN) != 0) {
mov CCSCBRAM, DINDEX;
} else {
mov DFDAT, DINDEX;
}
mov INITIATOR_TAG, DINDEX;
jmp ident_messages_done;
/*
* Pushed message loop to allow the kernel to
* run it's own target mode message state engine.
*/
host_target_message_loop:
mvi INTSTAT, HOST_MSG_LOOP;
nop;
cmp RETURN_1, EXIT_MSG_LOOP je target_ITloop;
test SSTAT0, SPIORDY jz .;
jmp host_target_message_loop;
ident_messages_done:
/* If ring buffer is full, return busy or queue full */
mov A, KERNEL_TQINPOS;
cmp TQINPOS, A jne tqinfifo_has_space;
mvi P_STATUS|BSYO call change_phase;
cmp INITIATOR_TAG, SCB_LIST_NULL je . + 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:
/* 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|IDENTIFY_SEEN;
test SCSISIGI, ATNI jnz target_mesgout_pending_msg;
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.
*/
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;
}
if ((ahc->flags & AHC_INITIATORMODE) != 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 */
and SAVED_TCL, SELID_MASK, SELID;
if ((ahc->features & AHC_TWIN) != 0) {
test SBLKCTL, SELBUSB jz . + 2;
or SAVED_TCL, SELBUSB;
}
or SXFRCTL0, SPIOEN|CLRSTCNT|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 */
and SCSISEQ, ENSELI|ENRSELI|ENAUTOATNP, SCSISEQ_TEMPLATE;
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 P_MESGIN|BSYO call change_phase;
mvi CLRSINT1,CLRBUSFREE;
/*
* 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_INITIATOR_TAG call target_outb;
mov INITIATOR_TAG, SCB_INITIATOR_TAG;
target_synccmd:
/*
* Now determine what phases the host wants us
* to go through.
*/
mov SEQ_FLAGS, SCB_TARGET_PHASES;
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;
if ((ahc->flags & AHC_PAGESCBS) != 0) {
mov ALLZEROS call get_free_or_disc_scb;
}
mov RETURN_1, ALLZEROS;
call complete_target_cmd;
cmp RETURN_1, CONT_MSG_LOOP jne .;
mvi DMAPARAMS, HDMAEN|DIRECTION|FIFORESET;
mov SCB_TAG call dma_scb;
jmp target_synccmd;
target_mesgout:
mvi SCSISIGO, P_MESGOUT|BSYO;
call target_inb;
/* Local Processing goes here... */
target_mesgout_pending_msg:
jmp host_target_message_loop;
target_disconnect:
mvi P_MESGIN|BSYO call change_phase;
test SEQ_FLAGS, DPHASE jz . + 2;
mvi MSG_SAVEDATAPOINTER call target_outb;
mvi MSG_DISCONNECT call target_outb;
target_busfree_wait:
/* Wait for preceeding I/O session to complete. */
test SCSISIGI, ACKI jnz .;
target_busfree:
clr SCSISIGO;
call complete_target_cmd;
jmp poll_for_work;
target_cmdphase:
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, TARG_SCSIRATE, A;
mov A, SINDIR;
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.
*/
test SCB_TARGET_PHASES[1], TARGET_DATA_IN jz . + 4;
mvi LASTPHASE, P_DATAOUT;
mvi P_DATAIN|BSYO call change_phase;
jmp . + 3;
mvi LASTPHASE, P_DATAIN;
mvi P_DATAOUT|BSYO call change_phase;
mov ALLZEROS call initialize_channel;
jmp p_data;
target_sphase:
mvi P_STATUS|BSYO call change_phase;
mvi LASTPHASE, P_STATUS;
mov SCB_TARGET_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 HCNT[0], 28;
clr HCNT[1];
clr HCNT[2];
or DFCNTRL, HDMAEN|FIFOFLUSH;
call dma_finish;
}
inc TQINPOS;
mvi INTSTAT,CMDCMPLT ret;
}
if ((ahc->flags & AHC_INITIATORMODE) != 0) {
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;
jmp ITloop; /* Try reading the bus again. */
await_busfree:
and SIMODE1, ~ENBUSFREE;
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:
/*
* 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;
/*
* 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;
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_ULTRA2) != 0) {
/*
* The preload circuitry requires us to
* reload the address too, so pull it from
* the shaddow address.
*/
bmov HADDR, SHADDR, 4;
bmov HCNT, SCB_RESID_DCNT, 3;
} else if ((ahc->features & AHC_CMD_CHAN) != 0) {
bmov STCNT, SCB_RESID_DCNT, 3;
} else {
mvi DINDEX, STCNT;
mvi SCB_RESID_DCNT call bcopy_3;
}
and DATA_COUNT_ODD, 0x1, SCB_RESID_DCNT[0];
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;
}
and DATA_COUNT_ODD, 0x1, SCB_DATACNT[0];
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;
}
/* Track odd'ness */
test HCNT[0], 0x1 jz . + 2;
xor DATA_COUNT_ODD, 0x1;
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;
if ((ahc->flags & AHC_TARGETMODE) != 0) {
test SSTAT0, TARGET jnz data_phase_loop;
}
test SSTAT1, REQINIT jz .;
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 ITloop;
and SEQ_FLAGS, ~DPHASE_PENDING;
/*
* For data-in phases, wait for any pending acks from the
* initiator before changing phase.
*/
test DFCNTRL, DIRECTION jz target_ITloop;
test SSTAT1, REQINIT jnz .;
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 .;
ultra2_dmafifoflush:
or DFCNTRL, FIFOFLUSH;
/*
* The FIFOEMP status bit on the Ultra2 class
* of controllers seems to be a bit flaky.
* It appears that if the FIFO is full and the
* transfer ends with some data in the REQ/ACK
* FIFO, FIFOEMP will fall temporarily
* as the data is transferred to the PCI bus.
* This glitch lasts for fewer than 5 clock cycles,
* so we work around the problem by ensuring the
* status bit stays false through a full glitch
* window.
*/
test DFSTATUS, FIFOEMP jz ultra2_dmafifoflush;
test DFSTATUS, FIFOEMP jz ultra2_dmafifoflush;
test DFSTATUS, FIFOEMP jz ultra2_dmafifoflush;
test DFSTATUS, FIFOEMP jz ultra2_dmafifoflush;
test DFSTATUS, FIFOEMP jz ultra2_dmafifoflush;
ultra2_dmafifoempty:
/* Don't clobber an inprogress host data transfer */
test DFSTATUS, MREQPEND jnz ultra2_dmafifoempty;
ultra2_dmahalt:
and DFCNTRL, ~(SCSIEN|HDMAEN);
test DFCNTRL, HDMAEN jnz .;
ret;
}
if ((ahc->flags & AHC_INITIATORMODE) != 0) {
/*
* 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 MSG_IDENTIFYFLAG, build a full
* indentify 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 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_retry:
or SCSISIGO,ATNO,LASTPHASE;/* turn on ATN for the retry */
p_mesgout:
mov SINDEX, MSG_OUT;
cmp SINDEX, MSG_IDENTIFYFLAG jne p_mesgout_from_host;
test SCB_CONTROL,MK_MESSAGE jnz host_message_loop;
mov FUNCTION1, SCB_TCL;
mov A, FUNCTION1;
if ((ahc->features & AHC_HS_MAILBOX) != 0) {
/*
* Work around a pausing bug in at least the aic7890.
* If the host needs to update the TARGET_MSG_REQUEST
* bit field, it will set the HS_MAILBOX to 1. In
* response, we pause with a specific interrupt code
* asking for the mask to be updated before we continue.
* Ugh.
*/
test HS_MAILBOX, 0xF0 jz . + 2;
mvi INTSTAT, UPDATE_TMSG_REQ;
nop;
}
mov SINDEX, TARGET_MSG_REQUEST[0];
if ((ahc->features & AHC_TWIN) != 0) {
/* Second Channel uses high byte bits */
test SCB_TCL, SELBUSB jz . + 2;
mov SINDEX, TARGET_MSG_REQUEST[1];
} else if ((ahc->features & AHC_WIDE) != 0) {
test SCB_TCL, 0x80 jz . + 2; /* target > 7 */
mov SINDEX, TARGET_MSG_REQUEST[1];
}
test SINDEX, A jnz host_message_loop;
p_mesgout_identify:
and SINDEX,LID,SCB_TCL; /* lun */
and A,DISCENB,SCB_CONTROL; /* mask off disconnect privledge */
or SINDEX,A; /* or in disconnect privledge */
or SINDEX,MSG_IDENTIFYFLAG;
/*
* 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;
p_mesgout_onebyte:
mvi CLRSINT1, CLRATNO;
mov SCSIDATL, SINDEX;
/*
* 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_NOOP je mesgin_done;
/*
* Pushed message loop to allow the kernel to
* RUN IT's 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 INTSTAT, HOST_MSG_LOOP;
call phase_lock;
cmp RETURN_1, EXIT_MSG_LOOP je ITloop + 1;
jmp host_message_loop;
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;
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_INITIATORMODE) != 0) {
/*
* 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;
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) {
/*
* 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 preceeding 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 waitat 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;
}
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 SCSISIGO, PHASE_MASK, SCSISIGI;
and LASTPHASE, PHASE_MASK, SCSISIGI 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;