cb0d548bf4
make the sequencer code fully compatible with the aic7870 (ie 294x adaptors). I've also added to my local mods putting the sequencer into "FASTMODE" clock. This gives upwards of 2M/sec write preformance improvement in some scenarios. There haven't been any reports of this causing problems, and I have been reaping the benifits of it for more than a week now. This also includes a new version of the pre-generated file <ugh> Obtained from: John Aycock (aycock@cpsc.ucalgary.ca) and myself
1068 lines
30 KiB
Plaintext
1068 lines
30 KiB
Plaintext
# @(#)aic7xxx.seq 1.31 94/11/25 jda
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#
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# Adaptec 274x device driver for Linux.
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# Copyright (c) 1994 The University of Calgary Department of Computer Science.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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VERSION AIC7XXX_SEQ_VERSION 1.31
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SCBMASK = 0x1f
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SCSISEQ = 0x00
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SXFRCTL0 = 0x01
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SXFRCTL1 = 0x02
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SCSISIGI = 0x03
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SCSISIGO = 0x03
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SCSIRATE = 0x04
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SCSIID = 0x05
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SCSIDATL = 0x06
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STCNT = 0x08
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STCNT+0 = 0x08
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STCNT+1 = 0x09
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STCNT+2 = 0x0a
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SSTAT0 = 0x0b
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CLRSINT1 = 0x0c
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SSTAT1 = 0x0c
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SIMODE1 = 0x11
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SCSIBUSL = 0x12
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SHADDR = 0x14
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SELID = 0x19
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SBLKCTL = 0x1f
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SEQCTL = 0x60
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A = 0x64 # == ACCUM
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SINDEX = 0x65
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DINDEX = 0x66
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ALLZEROS = 0x6a
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NONE = 0x6a
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SINDIR = 0x6c
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DINDIR = 0x6d
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FUNCTION1 = 0x6e
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HADDR = 0x88
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HCNT = 0x8c
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HCNT+0 = 0x8c
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HCNT+1 = 0x8d
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HCNT+2 = 0x8e
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SCBPTR = 0x90
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INTSTAT = 0x91
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DFCNTRL = 0x93
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DFSTATUS = 0x94
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DFDAT = 0x99
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QINFIFO = 0x9b
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QINCNT = 0x9c
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QOUTFIFO = 0x9d
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SCSICONF = 0x5a
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# The two reserved bytes at SCBARRAY+1[23] are expected to be set to
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# zero, and the reserved bit in SCBARRAY+0 is used as an internal flag
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# to indicate whether or not to reload scatter-gather parameters after
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# a disconnect.
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#
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SCBARRAY+0 = 0xa0
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SCBARRAY+1 = 0xa1
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SCBARRAY+2 = 0xa2
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SCBARRAY+3 = 0xa3
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SCBARRAY+7 = 0xa7
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SCBARRAY+11 = 0xab
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SCBARRAY+14 = 0xae
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SCBARRAY+15 = 0xaf
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SCBARRAY+16 = 0xb0
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SCBARRAY+17 = 0xb1
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SCBARRAY+18 = 0xb2
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SCBARRAY+19 = 0xb3
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SCBARRAY+20 = 0xb4
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SCBARRAY+21 = 0xb5
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SCBARRAY+22 = 0xb6
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SCBARRAY+23 = 0xb7
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SCBARRAY+24 = 0xb8
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SCBARRAY+25 = 0xb9
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SIGNAL_0 = 0x01 # unknown scsi bus phase
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SIGNAL_1 = 0x11 # message reject
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SIGNAL_2 = 0x21 # no IDENTIFY after reconnect
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SIGNAL_3 = 0x31 # no cmd match for reconnect
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SIGNAL_4 = 0x41 # SDTR -> SCSIRATE conversion
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STATUS_ERROR = 0x51
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# The host adapter card (at least the BIOS) uses 20-2f for SCSI
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# device information, 32-33 and 5a-5f as well. Since we don't support
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# wide or twin-bus SCSI, 28-2f can be reclaimed. As it turns out, the
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# BIOS trashes 20-27 anyway, writing the synchronous negotiation results
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# on top of the BIOS values, so we re-use those for our per-target
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# scratchspace (actually a value that can be copied directly into
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# SCSIRATE). This implies, since we can't get the BIOS config values,
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# that all targets will be negotiated with for synchronous transfer.
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# NEEDSDTR has one bit per target indicating if an SDTR message is
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# needed for that device - this will be set initially, as well as
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# after a bus reset condition.
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#
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# The high bit of DROPATN is set if ATN should be dropped before the ACK
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# when outb is called. REJBYTE contains the first byte of a MESSAGE IN
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# message, so the driver can report an intelligible error if a message is
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# rejected.
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#
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# RESELECT's high bit is true if we are currently handling a reselect;
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# its next-highest bit is true ONLY IF we've seen an IDENTIFY message
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# from the reselecting target. If we haven't had IDENTIFY, then we have
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# no idea what the lun is, and we can't select the right SCB register
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# bank, so force a kernel panic if the target attempts a data in/out or
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# command phase instead of corrupting something.
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#
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# Note that SG_NEXT occupies four bytes.
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#
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SYNCNEG = 0x20
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DISC_DSB_A = 0x32
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DROPATN = 0x30
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REJBYTE = 0x31
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RESELECT = 0x34
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MSG_FLAGS = 0x35
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MSG_LEN = 0x36
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MSG_START+0 = 0x37
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MSG_START+1 = 0x38
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MSG_START+2 = 0x39
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MSG_START+3 = 0x3a
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MSG_START+4 = 0x3b
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MSG_START+5 = 0x3c
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-MSG_START+0 = 0xc9 # 2's complement of MSG_START+0
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ARG_1 = 0x4c # sdtr conversion args & return
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ARG_2 = 0x4d
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RETURN_1 = 0x4c
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SIGSTATE = 0x4e # value written to SCSISIGO
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NEEDSDTR = 0x4f # send SDTR message, 1 bit/trgt
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SG_SIZEOF = 0x8 # sizeof(struct scatterlist)
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SG_NOLOAD = 0x50 # load SG pointer/length?
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SG_COUNT = 0x51 # working value of SG count
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SG_NEXT = 0x52 # working value of SG pointer
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SG_NEXT+0 = 0x52
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SG_NEXT+1 = 0x53
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SG_NEXT+2 = 0x54
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SG_NEXT+3 = 0x55
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SCBCOUNT = 0x56 # the actual number of SCBs
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ACTIVE_A = 0x57
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# Poll QINCNT for work - the lower bits contain
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# the number of entries in the Queue In FIFO.
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#
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start:
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test SCSISIGI,0x4 jnz reselect # BSYI
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test QINCNT,SCBMASK jz start
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# We have at least one queued SCB now. Set the SCB pointer
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# from the FIFO so we see the right bank of SCB registers,
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# then set SCSI options and set the initiator and target
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# SCSI IDs.
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#
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mov SCBPTR,QINFIFO
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# See if there is not already an active SCB for this target. This code
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# will have to be modified when we add support for dual and wide busses.
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and FUNCTION1,0x70,SCBARRAY+1
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mov A,FUNCTION1
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test ACTIVE_A,A jz active
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# Place the currently active back on the queue for later processing
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mov QINFIFO, SCBPTR
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jmp start
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# Mark the current target as busy and get working on the SCB
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active:
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or ACTIVE_A,A
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mov SCBARRAY+1 call initialize
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clr SG_NOLOAD
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clr RESELECT
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# As soon as we get a successful selection, the target should go
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# into the message out phase since we have ATN asserted. Prepare
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# the message to send, locking out the device driver. If the device
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# driver hasn't beaten us with an ABORT or RESET message, then tack
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# on an SDTR negotiation if required.
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#
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# Messages are stored in scratch RAM starting with a flag byte (high bit
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# set means active message), one length byte, and then the message itself.
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#
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mov SCBARRAY+1 call disconnect # disconnect ok?
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and SINDEX,0x7,SCBARRAY+1 # lun
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or SINDEX,A # return value from disconnect
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or SINDEX,0x80 call mk_mesg # IDENTIFY message
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mov A,SINDEX
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cmp MSG_START+0,A jne !message # did driver beat us?
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mvi MSG_START+1 call mk_sdtr # build SDTR message if needed
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!message:
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# Enable selection phase as an initiator, and do automatic ATN
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# after the selection.
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#
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mvi SCSISEQ,0x48 # ENSELO|ENAUTOATNO
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# Wait for successful arbitration. The AIC-7770 documentation says
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# that SELINGO indicates successful arbitration, and that it should
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# be used to look for SELDO. However, if the sequencer is paused at
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# just the right time - a parallel fsck(8) on two drives did it for
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# me - then SELINGO can flip back to false before we've seen it. This
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# makes the sequencer sit in the arbitration loop forever. This is
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# Not Good.
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#
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# Therefore, I've added a check in the arbitration loop for SELDO
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# too. This could arguably be made a critical section by disabling
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# pauses, but I don't want to make a potentially infinite loop a CS.
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# I suppose you could fold it into the select loop, too, but since
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# I've been hunting this bug for four days it's kinda like a trophy.
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#
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arbitrate:
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test SSTAT0,0x40 jnz *select # SELDO
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test SSTAT0,0x10 jz arbitrate # SELINGO
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# Wait for a successful selection. If the hardware selection
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# timer goes off, then the driver gets the interrupt, so we don't
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# need to worry about it.
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#
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select:
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test SSTAT0,0x40 jz select # SELDO
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jmp *select
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# Reselection is being initiated by a target - we've seen the BSY
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# line driven active, and we didn't do it! Enable the reselection
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# hardware, and wait for it to finish. Make a note that we've been
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# reselected, but haven't seen an IDENTIFY message from the target
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# yet.
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#
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reselect:
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mvi SCSISEQ,0x10 # ENRSELI
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reselect1:
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test SSTAT0,0x20 jz reselect1 # SELDI
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mov SELID call initialize
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mvi RESELECT,0x80 # reselected, no IDENTIFY
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# After the [re]selection, make sure that the [re]selection enable
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# bit is off. This chip is flaky enough without extra things
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# turned on. Also clear the BUSFREE bit in SSTAT1 since we'll be
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# using it shortly.
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#
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*select:
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clr SCSISEQ
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mvi CLRSINT1,0x8 # CLRBUSFREE
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# Main loop for information transfer phases. If BSY is false, then
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# we have a bus free condition, expected or not. Otherwise, wait
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# for the target to assert REQ before checking MSG, C/D and I/O
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# for the bus phase.
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#
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# We can't simply look at the values of SCSISIGI here (if we want
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# to do synchronous data transfer), because the target won't assert
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# REQ if it's already sent us some data that we haven't acknowledged
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# yet.
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#
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ITloop:
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test SSTAT1,0x8 jnz p_busfree # BUSFREE
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test SSTAT1,0x1 jz ITloop # REQINIT
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and A,0xe0,SCSISIGI # CDI|IOI|MSGI
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cmp ALLZEROS,A je p_dataout
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cmp A,0x40 je p_datain
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cmp A,0x80 je p_command
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cmp A,0xc0 je p_status
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cmp A,0xa0 je p_mesgout
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cmp A,0xe0 je p_mesgin
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mvi INTSTAT,SIGNAL_0 # unknown - signal driver
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p_dataout:
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mvi 0 call scsisig # !CDO|!IOO|!MSGO
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call assert
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call sg_load
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mvi A,3
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mvi DINDEX,HCNT
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mvi SCBARRAY+23 call bcopy
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mvi A,3
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mvi DINDEX,STCNT
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mvi SCBARRAY+23 call bcopy
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mvi A,4
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mvi DINDEX,HADDR
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mvi SCBARRAY+19 call bcopy
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mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN|
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# DIRECTION|FIFORESET
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# After a DMA finishes, save the final transfer pointer and count
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# back into the SCB, in case a device disconnects in the middle of
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# a transfer. Use SHADDR and STCNT instead of HADDR and HCNT, since
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# it's a reflection of how many bytes were transferred on the SCSI
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# (as opposed to the host) bus.
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#
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mvi A,3
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mvi DINDEX,SCBARRAY+23
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mvi STCNT call bcopy
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mvi A,4
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mvi DINDEX,SCBARRAY+19
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mvi SHADDR call bcopy
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call sg_advance
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mov SCBARRAY+18,SG_COUNT # residual S/G count
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jmp ITloop
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p_datain:
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mvi 0x40 call scsisig # !CDO|IOO|!MSGO
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call assert
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call sg_load
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mvi A,3
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mvi DINDEX,HCNT
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mvi SCBARRAY+23 call bcopy
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mvi A,3
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mvi DINDEX,STCNT
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mvi SCBARRAY+23 call bcopy
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mvi A,4
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mvi DINDEX,HADDR
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mvi SCBARRAY+19 call bcopy
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mvi 0x39 call dma # SCSIEN|SDMAEN|HDMAEN|
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# !DIRECTION|FIFORESET
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mvi A,3
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mvi DINDEX,SCBARRAY+23
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mvi STCNT call bcopy
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mvi A,4
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mvi DINDEX,SCBARRAY+19
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mvi SHADDR call bcopy
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call sg_advance
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mov SCBARRAY+18,SG_COUNT # residual S/G count
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jmp ITloop
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# Command phase. Set up the DMA registers and let 'er rip - the
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# two bytes after the SCB SCSI_cmd_length are zeroed by the driver,
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# so we can copy those three bytes directly into HCNT.
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#
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p_command:
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mvi 0x80 call scsisig # CDO|!IOO|!MSGO
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call assert
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mvi A,3
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mvi DINDEX,HCNT
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mvi SCBARRAY+11 call bcopy
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mvi A,3
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mvi DINDEX,STCNT
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mvi SCBARRAY+11 call bcopy
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mvi A,4
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mvi DINDEX,HADDR
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mvi SCBARRAY+7 call bcopy
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mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN|
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# DIRECTION|FIFORESET
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jmp ITloop
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# Status phase. Wait for the data byte to appear, then read it
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# and store it into the SCB.
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#
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p_status:
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mvi 0xc0 call scsisig # CDO|IOO|!MSGO
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mvi SCBARRAY+14 call inb
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jmp ITloop
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# Message out phase. If there is no active message, but the target
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# took us into this phase anyway, build a no-op message and send it.
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#
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p_mesgout:
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mvi 0xa0 call scsisig # CDO|!IOO|MSGO
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mvi 0x8 call mk_mesg # build NOP message
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# Set up automatic PIO transfer from MSG_START. Bit 3 in
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# SXFRCTL0 (SPIOEN) is already on.
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#
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mvi SINDEX,MSG_START+0
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mov DINDEX,MSG_LEN
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clr A
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# When target asks for a byte, drop ATN if it's the last one in
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# the message. Otherwise, keep going until the message is exhausted.
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# (We can't use outb for this since it wants the input in SINDEX.)
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#
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# Keep an eye out for a phase change, in case the target issues
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# a MESSAGE REJECT.
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#
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p_mesgout2:
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test SSTAT0,0x2 jz p_mesgout2 # SPIORDY
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test SSTAT1,0x10 jnz p_mesgout6 # PHASEMIS
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cmp DINDEX,1 jne p_mesgout3 # last byte?
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mvi CLRSINT1,0x40 # CLRATNO - drop ATN
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# Write a byte to the SCSI bus. The AIC-7770 refuses to automatically
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# send ACKs in automatic PIO or DMA mode unless you make sure that the
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# "expected" bus phase in SCSISIGO matches the actual bus phase. This
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# behaviour is completely undocumented and caused me several days of
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# grief.
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#
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# After plugging in different drives to test with and using a longer
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# SCSI cable, I found that I/O in Automatic PIO mode ceased to function,
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# especially when transferring >1 byte. It seems to be much more stable
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# if STCNT is set to one before the transfer, and SDONE (in SSTAT0) is
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# polled for transfer completion - for both output _and_ input. The
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# only theory I have is that SPIORDY doesn't drop right away when SCSIDATL
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# is accessed (like the documentation says it does), and that on a longer
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# cable run, the sequencer code was fast enough to loop back and see
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# an SPIORDY that hadn't dropped yet.
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#
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p_mesgout3:
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call one_stcnt
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mov SCSIDATL,SINDIR
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p_mesgout4:
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test SSTAT0,0x4 jz p_mesgout4 # SDONE
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dec DINDEX
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inc A
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cmp MSG_LEN,A jne p_mesgout2
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# If the next bus phase after ATN drops is a message out, it means
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# that the target is requesting that the last message(s) be resent.
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#
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p_mesgout5:
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test SSTAT1,0x8 jnz p_mesgout6 # BUSFREE
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test SSTAT1,0x1 jz p_mesgout5 # REQINIT
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and A,0xe0,SCSISIGI # CDI|IOI|MSGI
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cmp A,0xa0 jne p_mesgout6
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mvi 0x10 call scsisig # ATNO - re-assert ATN
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jmp ITloop
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p_mesgout6:
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mvi CLRSINT1,0x40 # CLRATNO - in case of PHASEMIS
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clr MSG_FLAGS # no active msg
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jmp ITloop
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# Message in phase. Bytes are read using Automatic PIO mode, but not
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# using inb. This alleviates a race condition, namely that if ATN had
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# to be asserted under Automatic PIO mode, it had to beat the SCSI
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# circuitry sending an ACK to the target. This showed up under heavy
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# loads and really confused things, since ABORT commands wouldn't be
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# seen by the drive after an IDENTIFY message in until it had changed
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# to a data I/O phase.
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#
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p_mesgin:
|
|
mvi 0xe0 call scsisig # CDO|IOO|MSGO
|
|
mvi A call inb_first # read the 1st message byte
|
|
mvi REJBYTE,A # save it for the driver
|
|
|
|
cmp ALLZEROS,A jne p_mesgin1
|
|
|
|
# We got a "command complete" message, so put the SCB pointer
|
|
# into the Queue Out, and trigger a completion interrupt.
|
|
# Check status for non zero return and interrupt driver if needed
|
|
# This allows the driver to do a sense command to find out the
|
|
# source of error. We don't bother to post to the QOUTFIFO in
|
|
# the error case 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, mark this target as free.
|
|
and FUNCTION1,0x70,SCBARRAY+1
|
|
mov A,FUNCTION1
|
|
xor ACTIVE_A,A
|
|
|
|
test SCBARRAY+14,0xff jz status_ok # 0 Status?
|
|
call inb_last # ack & turn auto PIO back on
|
|
mvi INTSTAT,STATUS_ERROR # let driver know
|
|
jmp ITloop
|
|
status_ok:
|
|
mov QOUTFIFO,SCBPTR
|
|
mvi INTSTAT,0x2 # CMDCMPLT
|
|
jmp p_mesgin_done
|
|
|
|
# Is it an extended message? We only support the synchronous data
|
|
# transfer request message, which will probably be in response to
|
|
# an SDTR message out from us. If it's not an SDTR, reject it -
|
|
# apparently this can be done after any message in byte, according
|
|
# to the SCSI-2 spec.
|
|
#
|
|
# XXX - we should really reject this if we didn't initiate the SDTR
|
|
# negotiation; this may cause problems with unusual devices.
|
|
#
|
|
p_mesgin1:
|
|
cmp A,1 jne p_mesgin2 # extended message code?
|
|
|
|
mvi A call inb_next
|
|
cmp A,3 jne p_mesginN # extended mesg length = 3
|
|
mvi A call inb_next
|
|
cmp A,1 jne p_mesginN # SDTR code
|
|
|
|
mvi ARG_1 call inb_next # xfer period
|
|
mvi ARG_2 call inb_next # REQ/ACK offset
|
|
mvi INTSTAT,SIGNAL_4 # call driver to convert
|
|
|
|
call ndx_sdtr # index sync config for target
|
|
mov DINDEX,SINDEX
|
|
mov DINDIR,RETURN_1 # save returned value
|
|
|
|
not A # turn off "need sdtr" flag
|
|
and NEEDSDTR,A
|
|
|
|
# Even though the SCSI-2 specification says that a device responding
|
|
# to our SDTR message should honor our parameters for transmitting
|
|
# to us, it doesn't seem to work too well in real life. In particular,
|
|
# a lot of CD-ROM and tape units don't function: try using the SDTR
|
|
# parameters the device sent us for both transmitting and receiving.
|
|
#
|
|
mov SCSIRATE,RETURN_1
|
|
jmp p_mesgin_done
|
|
|
|
# Is it a disconnect message? Set a flag in the SCB to remind us
|
|
# and await the bus going free.
|
|
#
|
|
p_mesgin2:
|
|
cmp A,4 jne p_mesgin3 # disconnect code?
|
|
|
|
or SCBARRAY+0,0x4 # set "disconnected" bit
|
|
jmp p_mesgin_done
|
|
|
|
# Save data pointers message? Copy working values into the SCB,
|
|
# usually in preparation for a disconnect.
|
|
#
|
|
p_mesgin3:
|
|
cmp A,2 jne p_mesgin4 # save data pointers code?
|
|
|
|
call sg_ram2scb
|
|
jmp p_mesgin_done
|
|
|
|
# Restore pointers message? Data pointers are recopied from the
|
|
# SCB anyway at the start of any DMA operation, so the only thing
|
|
# to copy is the scatter-gather values.
|
|
#
|
|
p_mesgin4:
|
|
cmp A,3 jne p_mesgin5 # restore pointers code?
|
|
|
|
call sg_scb2ram
|
|
jmp p_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.
|
|
#
|
|
p_mesgin5:
|
|
test A,0x80 jz p_mesgin6 # identify message?
|
|
|
|
test A,0x78 jnz p_mesginN # !DiscPriv|!LUNTAR|!Reserved
|
|
|
|
mov A call findSCB # switch to correct SCB
|
|
|
|
# If a active message is present after calling findSCB, then either it
|
|
# or the driver is trying to abort the command. Either way, something
|
|
# untoward has happened and we should just leave it alone.
|
|
#
|
|
test MSG_FLAGS,0x80 jnz p_mesgin_done
|
|
|
|
xor SCBARRAY+0,0x4 # clear disconnect bit in SCB
|
|
mvi RESELECT,0xc0 # make note of IDENTIFY
|
|
|
|
call sg_scb2ram # implied restore pointers
|
|
# required on reselect
|
|
jmp p_mesgin_done
|
|
|
|
# Message reject? If we have an outstanding SDTR negotiation, assume
|
|
# that it's a response from the target selecting asynchronous transfer,
|
|
# otherwise just ignore it since we have no clue what it pertains to.
|
|
#
|
|
# XXX - I don't have a device that responds this way. Does this code
|
|
# actually work?
|
|
#
|
|
p_mesgin6:
|
|
cmp A,7 jne p_mesgin7 # message reject code?
|
|
|
|
and FUNCTION1,0x70,SCSIID # outstanding SDTR message?
|
|
mov A,FUNCTION1
|
|
test NEEDSDTR,A jz p_mesgin_done # no - ignore rejection
|
|
|
|
call ndx_sdtr # note use of asynch xfer
|
|
mov DINDEX,SINDEX
|
|
clr DINDIR
|
|
|
|
not A # turn off "active sdtr" flag
|
|
and NEEDSDTR,A
|
|
|
|
clr SCSIRATE # select asynch xfer
|
|
jmp p_mesgin_done
|
|
|
|
# [ ADD MORE MESSAGE HANDLING HERE ]
|
|
#
|
|
p_mesgin7:
|
|
|
|
# We have no idea what this message in is, and there's no way
|
|
# to pass it up to the kernel, so we issue a message reject and
|
|
# hope for the best. Since we're now using manual PIO mode to
|
|
# read in the message, there should no longer be a race condition
|
|
# present when we assert ATN. In any case, rejection should be a
|
|
# rare occurrence - signal the driver when it happens.
|
|
#
|
|
p_mesginN:
|
|
or SINDEX,0x10,SIGSTATE # turn on ATNO
|
|
call scsisig
|
|
mvi INTSTAT,SIGNAL_1 # let driver know
|
|
|
|
mvi 0x7 call mk_mesg # MESSAGE REJECT message
|
|
|
|
p_mesgin_done:
|
|
call inb_last # ack & turn auto PIO back on
|
|
jmp ITloop
|
|
|
|
# Bus free phase. It might be useful to interrupt the device
|
|
# driver if we aren't expecting this. For now, make sure that
|
|
# ATN isn't being asserted and look for a new command.
|
|
#
|
|
p_busfree:
|
|
mvi CLRSINT1,0x40 # CLRATNO
|
|
clr SIGSTATE
|
|
jmp start
|
|
|
|
# Bcopy: number of bytes to transfer should be in A, DINDEX should
|
|
# contain the destination address, and SINDEX should contain the
|
|
# source address. All input parameters are trashed on return.
|
|
#
|
|
bcopy:
|
|
mov DINDIR,SINDIR
|
|
dec A
|
|
cmp ALLZEROS,A jne bcopy
|
|
ret
|
|
|
|
# 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:
|
|
mvi SEQCTL,0x50 # PAUSEDIS|FASTMODE
|
|
test MSG_FLAGS,0x80 jnz mk_mesg1 # active message?
|
|
|
|
mvi MSG_FLAGS,0x80 # if not, there is now
|
|
mvi MSG_LEN,1 # length = 1
|
|
mov MSG_START+0,SINDEX # 1-byte message
|
|
|
|
mk_mesg1:
|
|
mvi SEQCTL,0x10 # !PAUSEDIS|FASTMODE
|
|
ret
|
|
|
|
# Input byte in Automatic PIO mode. The address to store the byte
|
|
# in should be in SINDEX. DINDEX will be used by this routine.
|
|
#
|
|
inb:
|
|
test SSTAT0,0x2 jz inb # SPIORDY
|
|
mov DINDEX,SINDEX
|
|
call one_stcnt # xfer one byte
|
|
mov DINDIR,SCSIDATL
|
|
inb1:
|
|
test SSTAT0,0x4 jz inb1 # SDONE - wait to "finish"
|
|
ret
|
|
|
|
# Carefully read data in Automatic PIO mode. I first tried this using
|
|
# Manual PIO mode, but it gave me continual underrun errors, probably
|
|
# indicating that I did something wrong, but I feel more secure leaving
|
|
# Automatic PIO on all the time.
|
|
#
|
|
# 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_first:
|
|
mov DINDEX,SINDEX
|
|
mov DINDIR,SCSIBUSL ret # read byte directly from bus
|
|
|
|
inb_next:
|
|
mov DINDEX,SINDEX # save SINDEX
|
|
|
|
call one_stcnt # xfer one byte
|
|
mov NONE,SCSIDATL # dummy read from latch to ACK
|
|
inb_next1:
|
|
test SSTAT0,0x4 jz inb_next1 # SDONE
|
|
inb_next2:
|
|
test SSTAT0,0x2 jz inb_next2 # SPIORDY - wait for next byte
|
|
mov DINDIR,SCSIBUSL ret # read byte directly from bus
|
|
|
|
inb_last:
|
|
call one_stcnt # ACK with dummy read
|
|
mov NONE,SCSIDATL
|
|
inb_last1:
|
|
test SSTAT0,0x4 jz inb_last1 # wait for completion
|
|
ret
|
|
|
|
# Output byte in Automatic PIO mode. The byte to output should be
|
|
# in SINDEX. If DROPATN's high bit is set, then ATN will be dropped
|
|
# before the byte is output.
|
|
#
|
|
outb:
|
|
test SSTAT0,0x2 jz outb # SPIORDY
|
|
call one_stcnt # xfer one byte
|
|
|
|
test DROPATN,0x80 jz outb1
|
|
mvi CLRSINT1,0x40 # CLRATNO
|
|
clr DROPATN
|
|
outb1:
|
|
mov SCSIDATL,SINDEX
|
|
outb2:
|
|
test SSTAT0,0x4 jz outb2 # SDONE
|
|
ret
|
|
|
|
# Write the value "1" into the STCNT registers, for Automatic PIO
|
|
# transfers.
|
|
#
|
|
one_stcnt:
|
|
clr STCNT+2
|
|
clr STCNT+1
|
|
mvi STCNT+0,1 ret
|
|
|
|
# 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
|
|
dma1:
|
|
dma2:
|
|
test SSTAT0,0x1 jnz dma3 # DMADONE
|
|
test SSTAT1,0x10 jz dma1 # PHASEMIS, ie. underrun
|
|
|
|
# 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.
|
|
#
|
|
dma3:
|
|
test SINDEX,0x4 jnz dma5 # DIRECTION
|
|
dma4:
|
|
test DFSTATUS,0x1 jz dma4 # FIFOFLUSHACK
|
|
|
|
# Now shut the DMA enables off, and copy STCNT (ie. the underrun
|
|
# amount, if any) to the SCB registers; SG_COUNT will get copied to
|
|
# the SCB's residual S/G count field after sg_advance is called. Make
|
|
# sure that the DMA enables are actually off first lest we get an ILLSADDR.
|
|
#
|
|
dma5:
|
|
clr DFCNTRL # disable DMA
|
|
dma6:
|
|
test DFCNTRL,0x38 jnz dma6 # SCSIENACK|SDMAENACK|HDMAENACK
|
|
|
|
mvi A,3
|
|
mvi DINDEX,SCBARRAY+15
|
|
mvi STCNT call bcopy
|
|
|
|
ret
|
|
|
|
# Common SCSI initialization for selection and reselection. Expects
|
|
# the target SCSI ID to be in the upper four bits of SINDEX, and A's
|
|
# contents are stomped on return.
|
|
#
|
|
initialize:
|
|
clr SBLKCTL # channel A, !wide
|
|
and SCSIID,0xf0,SINDEX # target ID
|
|
and A,0x7,SCSICONF # SCSI_ID_A[210]
|
|
or SCSIID,A
|
|
|
|
# Esundry initialization.
|
|
#
|
|
clr DROPATN
|
|
clr SIGSTATE
|
|
|
|
# Turn on Automatic PIO mode now, before we expect to see an REQ
|
|
# from the target. It shouldn't hurt anything to leave it on. Set
|
|
# CLRCHN here before the target has entered a data transfer mode -
|
|
# with synchronous SCSI, if you do it later, you blow away some
|
|
# data in the SCSI FIFO that the target has already sent to you.
|
|
#
|
|
# DFON is a 7870 bit enabling digital filtering of REQ and ACK signals.
|
|
#
|
|
mvi SXFRCTL0,0x8a # DFON|SPIOEN|CLRCHN
|
|
|
|
# Set SCSI bus parity checking and the selection timeout value,
|
|
# and enable the hardware selection timer. Set the SELTO interrupt
|
|
# to signal the driver.
|
|
#
|
|
# STPWEN is 7870-specific, enabling an external termination power source.
|
|
#
|
|
and A,0x38,SCSICONF # PARITY_ENB_A|SEL_TIM_A[10]
|
|
or SXFRCTL1,0x5,A # ENSTIMER|STPWEN
|
|
mvi SIMODE1,0x84 # ENSELTIMO|ENSCSIPERR
|
|
|
|
# Initialize scatter-gather pointers by setting up the working copy
|
|
# in scratch RAM.
|
|
#
|
|
call sg_scb2ram
|
|
|
|
# Initialize SCSIRATE with the appropriate value for this target.
|
|
#
|
|
call ndx_sdtr
|
|
mov SCSIRATE,SINDIR
|
|
ret
|
|
|
|
# Assert that if we've been reselected, then we've seen an IDENTIFY
|
|
# message.
|
|
#
|
|
assert:
|
|
test RESELECT,0x80 jz assert1 # reselected?
|
|
test RESELECT,0x40 jnz assert1 # seen IDENTIFY?
|
|
|
|
mvi INTSTAT,SIGNAL_2 # no - cause a kernel panic
|
|
|
|
assert1:
|
|
ret
|
|
|
|
# Find out if disconnection is ok from the information the BIOS has left
|
|
# us. The target ID should be in the upper four bits of SINDEX; A will
|
|
# contain either 0x40 (disconnection ok) or 0x00 (disconnection not ok)
|
|
# on exit.
|
|
#
|
|
# This is the only place the target ID is limited to three bits, so we
|
|
# can use the FUNCTION1 register.
|
|
#
|
|
disconnect:
|
|
and FUNCTION1,0x70,SINDEX # strip off extra just in case
|
|
mov A,FUNCTION1
|
|
test DISC_DSB_A,A jz disconnect1 # bit nonzero if DISabled
|
|
|
|
clr A ret
|
|
disconnect1:
|
|
mvi A,0x40 ret
|
|
|
|
# Locate the SCB matching the target ID in SELID and the lun in the lower
|
|
# three bits of SINDEX, and switch the SCB to it. Have the kernel print
|
|
# a warning message if it can't be found, and generate an ABORT message
|
|
# to the target. We keep the value of the t/c/l that we are trying to find
|
|
# in DINDEX so it is not overwritten during our check to see if we are
|
|
# at the last SCB.
|
|
#
|
|
findSCB:
|
|
and A,0x7,SINDEX # lun in lower three bits
|
|
or DINDEX,A,SELID # can I do this?
|
|
and DINDEX,0xf7 # only channel A implemented
|
|
|
|
clr SINDEX
|
|
|
|
findSCB1:
|
|
mov A,DINDEX
|
|
mov SCBPTR,SINDEX # switch to new SCB
|
|
cmp SCBARRAY+1,A jne findSCB2 # target ID/channel/lun match?
|
|
test SCBARRAY+0,0x4 jz findSCB2 # should be disconnected
|
|
|
|
ret
|
|
|
|
findSCB2:
|
|
inc SINDEX
|
|
mov A,SCBCOUNT
|
|
cmp SINDEX,A jne findSCB1
|
|
|
|
mvi INTSTAT,SIGNAL_3 # not found - signal kernel
|
|
mvi 0x6 call mk_mesg # ABORT message
|
|
|
|
or SINDEX,0x10,SIGSTATE # assert ATNO
|
|
call scsisig
|
|
ret
|
|
|
|
# Make a working copy of the scatter-gather parameters in the SCB.
|
|
#
|
|
sg_scb2ram:
|
|
mov SG_COUNT,SCBARRAY+2
|
|
|
|
mvi A,4
|
|
mvi DINDEX,SG_NEXT
|
|
mvi SCBARRAY+3 call bcopy
|
|
|
|
mvi SG_NOLOAD,0x80
|
|
test SCBARRAY+0,0x10 jnz sg_scb2ram1 # don't reload s/g?
|
|
clr SG_NOLOAD
|
|
|
|
sg_scb2ram1:
|
|
ret
|
|
|
|
# Copying RAM values back to SCB, for Save Data Pointers message.
|
|
#
|
|
sg_ram2scb:
|
|
mov SCBARRAY+2,SG_COUNT
|
|
|
|
mvi A,4
|
|
mvi DINDEX,SCBARRAY+3
|
|
mvi SG_NEXT call bcopy
|
|
|
|
and SCBARRAY+0,0xef,SCBARRAY+0
|
|
test SG_NOLOAD,0x80 jz sg_ram2scb1 # reload s/g?
|
|
or SCBARRAY+0,0x10
|
|
|
|
sg_ram2scb1:
|
|
ret
|
|
|
|
# Load a struct scatter if needed 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 the above DMA, assumes a little-endian host data storage.
|
|
#
|
|
sg_load:
|
|
test SG_COUNT,0xff jz sg_load3 # SG being used?
|
|
test SG_NOLOAD,0x80 jnz sg_load3 # don't reload s/g?
|
|
|
|
clr HCNT+2
|
|
clr HCNT+1
|
|
mvi HCNT+0,SG_SIZEOF
|
|
|
|
mvi A,4
|
|
mvi DINDEX,HADDR
|
|
mvi SG_NEXT call bcopy
|
|
|
|
mvi DFCNTRL,0xd # HDMAEN|DIRECTION|FIFORESET
|
|
|
|
# Wait for DMA from host memory to data FIFO to complete, then disable
|
|
# DMA and wait for it to acknowledge that it's off.
|
|
#
|
|
sg_load1:
|
|
test DFSTATUS,0x8 jz sg_load1 # HDONE
|
|
|
|
clr DFCNTRL # disable DMA
|
|
sg_load2:
|
|
test DFCNTRL,0x8 jnz sg_load2 # HDMAENACK
|
|
|
|
# Copy data from FIFO into SCB data pointer and data count. This assumes
|
|
# that the struct scatterlist has this structure (this and sizeof(struct
|
|
# scatterlist) == 12 are asserted in aic7xxx.c):
|
|
#
|
|
# struct scatterlist {
|
|
# char *address; /* four bytes, little-endian order */
|
|
# ... /* four bytes, ignored */
|
|
# unsigned short length; /* two bytes, little-endian order */
|
|
# }
|
|
#
|
|
|
|
# Not in FreeBSD. the scatter list is only 8 bytes.
|
|
#
|
|
# struct ahc_dma_seg {
|
|
# physaddr addr; /* four bytes, little-endian order */
|
|
# long len; /* four bytes, little endian order */
|
|
# };
|
|
#
|
|
|
|
mov SCBARRAY+19,DFDAT # new data address
|
|
mov SCBARRAY+20,DFDAT
|
|
mov SCBARRAY+21,DFDAT
|
|
mov SCBARRAY+22,DFDAT
|
|
|
|
mov SCBARRAY+23,DFDAT
|
|
mov SCBARRAY+24,DFDAT
|
|
mov SCBARRAY+25,DFDAT
|
|
mov NONE,DFDAT #Only support 24 bit length.
|
|
|
|
sg_load3:
|
|
ret
|
|
|
|
# Advance the scatter-gather pointers only IF NEEDED. If SG is enabled,
|
|
# and the SCSI transfer count is zero (note that this should be called
|
|
# right after a DMA finishes), then move the working copies of the SG
|
|
# pointer/length along. If the SCSI transfer count is not zero, then
|
|
# presumably the target is disconnecting - do not reload the SG values
|
|
# next time.
|
|
#
|
|
sg_advance:
|
|
test SG_COUNT,0xff jz sg_advance2 # s/g enabled?
|
|
|
|
test STCNT+0,0xff jnz sg_advance1 # SCSI transfer count nonzero?
|
|
test STCNT+1,0xff jnz sg_advance1
|
|
test STCNT+2,0xff jnz sg_advance1
|
|
|
|
clr SG_NOLOAD # reload s/g next time
|
|
dec SG_COUNT # one less segment to go
|
|
|
|
clr A # add sizeof(struct scatter)
|
|
add SG_NEXT+0,SG_SIZEOF,SG_NEXT+0
|
|
adc SG_NEXT+1,A,SG_NEXT+1
|
|
adc SG_NEXT+2,A,SG_NEXT+2
|
|
adc SG_NEXT+3,A,SG_NEXT+3
|
|
|
|
ret
|
|
|
|
sg_advance1:
|
|
mvi SG_NOLOAD,0x80 # don't reload s/g next time
|
|
sg_advance2:
|
|
ret
|
|
|
|
# Add the array base SYNCNEG to the target offset (the target address
|
|
# is in SCSIID), and return the result in SINDEX. The accumulator
|
|
# contains the 3->8 decoding of the target ID on return.
|
|
#
|
|
ndx_sdtr:
|
|
shr A,SCSIID,4
|
|
and A,0x7
|
|
add SINDEX,SYNCNEG,A
|
|
|
|
and FUNCTION1,0x70,SCSIID # 3-bit target address decode
|
|
mov A,FUNCTION1 ret
|
|
|
|
# If we need to negotiate transfer parameters, build the SDTR message
|
|
# starting at the address passed in SINDEX. DINDEX is modified on return.
|
|
#
|
|
mk_sdtr:
|
|
mov DINDEX,SINDEX # save SINDEX
|
|
|
|
call ndx_sdtr
|
|
test NEEDSDTR,A jnz mk_sdtr1 # do we need negotiation?
|
|
ret
|
|
|
|
mk_sdtr1:
|
|
mvi DINDIR,1 # extended message
|
|
mvi DINDIR,3 # extended message length = 3
|
|
mvi DINDIR,1 # SDTR code
|
|
mvi DINDIR,25 # REQ/ACK transfer period
|
|
mvi DINDIR,15 # REQ/ACK offset
|
|
|
|
add MSG_LEN,-MSG_START+0,DINDEX # update message length
|
|
ret
|
|
|
|
# Set SCSI bus control signal state. This also saves the last-written
|
|
# value into a location where the higher-level driver can read it - if
|
|
# it has to send an ABORT or RESET message, then it needs to know this
|
|
# so it can assert ATN without upsetting SCSISIGO. The new value is
|
|
# expected in SINDEX. Change the actual state last to avoid contention
|
|
# from the driver.
|
|
#
|
|
scsisig:
|
|
mov SIGSTATE,SINDEX
|
|
mov SCSISIGO,SINDEX ret
|