1235 lines
36 KiB
Plaintext
1235 lines
36 KiB
Plaintext
# @(#)aic7xxx.seq 1.32 94/11/29 jda
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#
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# Adaptec 274x/284x/294x device driver for Linux and FreeBSD.
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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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#
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# FreeBSD, Twin, Wide, 2 command per target support, tagged queuing and other
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# optimizations provided by Justin T. Gibbs (gibbs@FreeBSD.org)
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#
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VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.12 1995/04/01 19:51:40 gibbs Exp $"
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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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HADDR+1 = 0x89
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HADDR+2 = 0x8a
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HADDR+3 = 0x8b
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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_A = 0x5a
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SCSICONF_B = 0x5b
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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. We also use bits 6 & 7 to indicate whether or not to
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# initiate SDTR or WDTR repectively when starting this command.
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#
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SCBARRAY+0 = 0xa0
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DISCONNECTED = 0x04
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NEEDDMA = 0x08
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SG_LOAD = 0x10
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TAG_ENB = 0x20
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NEEDSDTR = 0x40
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NEEDWDTR = 0x80
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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+4 = 0xa4
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SCBARRAY+5 = 0xa5
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SCBARRAY+6 = 0xa6
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SCBARRAY+7 = 0xa7
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SCBARRAY+8 = 0xa8
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SCBARRAY+9 = 0xa9
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SCBARRAY+10 = 0xaa
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SCBARRAY+11 = 0xab
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SCBARRAY+12 = 0xac
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SCBARRAY+13 = 0xad
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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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SCBARRAY+26 = 0xba
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SCBARRAY+27 = 0xbb
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SCBARRAY+28 = 0xbc
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SCBARRAY+29 = 0xbd
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BAD_PHASE = 0x01 # unknown scsi bus phase
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CMDCMPLT = 0x02
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SEND_REJECT = 0x11 # sending a message reject
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NO_IDENT = 0x21 # no IDENTIFY after reconnect
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NO_MATCH = 0x31 # no cmd match for reconnect
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MSG_SDTR = 0x41 # SDTR message recieved
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MSG_WDTR = 0x51 # WDTR message recieved
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MSG_REJECT = 0x61 # Reject message recieved
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BAD_STATUS = 0x71 # Bad status from target
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RESIDUAL = 0x81 # Residual byte count != 0
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ABORT_TAG = 0x91 # Sent an ABORT_TAG message
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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. As it turns out, the
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# BIOS trashes 20-2f, 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). The kernel driver will enable synchronous negotiation
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# for all targets that have a value other than 0 in the lower four
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# bits of the target scratch space. This should work irregardless of
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# whether the bios has been installed. NEEDWDTR and NEEDSDTR are the top
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# two bits of the SCB control byte. The kernel driver will set these
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# when a WDTR or SDTR message should be sent to the target the SCB's
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# command references.
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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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# FLAGS'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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DROPATN = 0x30
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REJBYTE = 0x31
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DISC_DSB_A = 0x32
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DISC_DSB_B = 0x33
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MSG_LEN = 0x34
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MSG_START+0 = 0x35
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MSG_START+1 = 0x36
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MSG_START+2 = 0x37
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MSG_START+3 = 0x38
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MSG_START+4 = 0x39
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MSG_START+5 = 0x3a
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-MSG_START+0 = 0xcb # 2's complement of MSG_START+0
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ARG_1 = 0x4a # sdtr conversion args & return
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BUS_16_BIT = 0x01
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RETURN_1 = 0x4a
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SIGSTATE = 0x4b # value written to SCSISIGO
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# Linux users should use 0xc (12) for SG_SIZEOF
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SG_SIZEOF = 0x8 # sizeof(struct ahc_dma)
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#SG_SIZEOF = 0xc # sizeof(struct scatterlist)
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SCB_SIZEOF = 0x13 # sizeof SCB to DMA (19 bytes)
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SG_NOLOAD = 0x4c # load SG pointer/length?
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SG_COUNT = 0x4d # working value of SG count
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SG_NEXT = 0x4e # working value of SG pointer
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SG_NEXT+0 = 0x4e
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SG_NEXT+1 = 0x4f
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SG_NEXT+2 = 0x50
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SG_NEXT+3 = 0x51
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SCBCOUNT = 0x52 # the actual number of SCBs
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FLAGS = 0x53 # Device configuration flags
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TWIN_BUS = 0x01
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WIDE_BUS = 0x02
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MAX_SYNC = 0x08
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SENSE = 0x10
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ACTIVE_MSG = 0x20
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IDENTIFY_SEEN = 0x40
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RESELECTED = 0x80
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ACTIVE_A = 0x54
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ACTIVE_B = 0x55
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SAVED_TCL = 0x56
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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 FLAGS,SENSE jnz start_sense
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start_nosense:
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test FLAGS,TWIN_BUS jz start2 # Are we a twin channel device?
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# For fairness, we check the other bus first, since we just finished a
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# transaction on the current channel.
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xor SBLKCTL,0x08 # Toggle to the other bus
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test SCSISIGI,0x4 jnz reselect # BSYI
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xor SBLKCTL,0x08 # Toggle to the original bus
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start2:
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test SCSISIGI,0x4 jnz reselect # BSYI
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test QINCNT,SCBMASK jz start_nosense
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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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# If the control byte of this SCB has the NEEDDMA flag set, we have
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# yet to DMA it from host memory
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test SCBARRAY+0,NEEDDMA jz test_busy
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clr HCNT+2
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clr HCNT+1
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mvi HCNT+0,SCB_SIZEOF
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mvi DINDEX,HADDR
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mvi SCBARRAY+26 call bcopy_4
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mvi DFCNTRL,0xd # HDMAEN|DIRECTION|FIFORESET
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# Wait for DMA from host memory to data FIFO to complete, then disable
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# DMA and wait for it to acknowledge that it's off.
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#
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call dma_finish
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# Copy the SCB from the FIFO to the SCBARRAY
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mvi DINDEX, SCBARRAY+0
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call bcopy_3_dfdat
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call bcopy_4_dfdat
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call bcopy_4_dfdat
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call bcopy_4_dfdat
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call bcopy_4_dfdat
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# See if there is not already an active SCB for this target. This code
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# locks out on a per target basis instead of target/lun. Although this
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# is not ideal for devices that have multiple luns active at the same
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# time, it is faster than looping through all SCB's looking for active
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# commands. It may be benificial to make findscb a more general procedure
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# to see if the added cost of the search is negligible. This code also
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# assumes that the kernel driver will clear the active flags on board
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# initialization, board reset, and a target's SELTO.
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test_busy:
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test SCBARRAY+0,0x20 jnz start_scb
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and FUNCTION1,0x70,SCBARRAY+1
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mov A,FUNCTION1
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test SCBARRAY+1,0x88 jz test_a # Id < 8 && A channel
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test ACTIVE_B,A jnz requeue
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or ACTIVE_B,A # Mark the current target as busy
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jmp start_scb
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start_sense:
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# Clear the SENSE flag first, then do a normal start_scb
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and FLAGS,0xef
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jmp start_scb
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# Place the currently active back on the queue for later processing
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requeue:
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mov QINFIFO, SCBPTR
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jmp start_nosense
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test_a:
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test ACTIVE_A,A jnz requeue
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or ACTIVE_A,A # Mark the current target as busy
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start_scb:
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or SCBARRAY+0,NEEDDMA
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and SINDEX,0xf7,SBLKCTL #Clear the channel select bit
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and A,0x08,SCBARRAY+1 #Get new channel bit
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or SINDEX,A
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mov SBLKCTL,SINDEX # select channel
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mov SCBARRAY+1 call initialize
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clr SG_NOLOAD
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and FLAGS,0x3f # !RESELECTING
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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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test SCBARRAY+0,0xe0 jz !message # WDTR, SDTR or TAG??
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cmp MSG_START+0,A jne !message # did driver beat us?
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# Tag Message if Tag enabled in SCB control block. Use SCBPTR as the tag
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# value
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mk_tag:
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mvi DINDEX, MSG_START+1
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test SCBARRAY+0,TAG_ENB jz mk_tag_done
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and A,0x23,SCBARRAY+0
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mov DINDIR,A
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mov DINDIR,SCBPTR
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add MSG_LEN,-MSG_START+0,DINDEX # update message length
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mk_tag_done:
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mov DINDEX call mk_dtr # build DTR 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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and FLAGS,0x3f # reselected, no IDENTIFY
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or FLAGS,RESELECTED
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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,BAD_PHASE # 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 DINDEX,HADDR
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mvi SCBARRAY+19 call bcopy_4
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# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR
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mvi SCBARRAY+23 call bcopy_3
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mvi DINDEX,STCNT
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mvi SCBARRAY+23 call bcopy_3
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# If we are the last SG block, don't set wideodd.
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test SCBARRAY+18,0xff jnz p_dataout_wideodd
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mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN|
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# DIRECTION|FIFORESET
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jmp p_dataout_rest
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p_dataout_wideodd:
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mvi 0xbd call dma # WIDEODD|SCSIEN|SDMAEN|HDMAEN|
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# DIRECTION|FIFORESET
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p_dataout_rest:
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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 DINDEX,SCBARRAY+23
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mvi STCNT call bcopy_3
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mvi DINDEX,SCBARRAY+19
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mvi SHADDR call bcopy_4
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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 DINDEX,HADDR
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mvi SCBARRAY+19 call bcopy_4
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# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR
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mvi SCBARRAY+23 call bcopy_3
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mvi DINDEX,STCNT
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mvi SCBARRAY+23 call bcopy_3
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# If we are the last SG block, don't set wideodd.
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test SCBARRAY+18,0xff jnz p_datain_wideodd
|
|
mvi 0x39 call dma # SCSIEN|SDMAEN|HDMAEN|
|
|
# !DIRECTION|FIFORESET
|
|
jmp p_datain_rest
|
|
p_datain_wideodd:
|
|
mvi 0xb9 call dma # WIDEODD|SCSIEN|SDMAEN|HDMAEN|
|
|
# !DIRECTION|FIFORESET
|
|
p_datain_rest:
|
|
mvi DINDEX,SCBARRAY+23
|
|
mvi STCNT call bcopy_3
|
|
|
|
mvi DINDEX,SCBARRAY+19
|
|
mvi SHADDR call bcopy_4
|
|
|
|
call sg_advance
|
|
mov SCBARRAY+18,SG_COUNT # residual S/G count
|
|
|
|
jmp ITloop
|
|
|
|
# Command phase. Set up the DMA registers and let 'er rip - the
|
|
# two bytes after the SCB SCSI_cmd_length are zeroed by the driver,
|
|
# so we can copy those three bytes directly into HCNT.
|
|
#
|
|
p_command:
|
|
mvi 0x80 call scsisig # CDO|!IOO|!MSGO
|
|
call assert
|
|
|
|
mvi DINDEX,HADDR
|
|
mvi SCBARRAY+7 call bcopy_4
|
|
|
|
# mvi DINDEX,HCNT # implicit since HCNT is next to HADDR
|
|
mvi SCBARRAY+11 call bcopy_3
|
|
|
|
mvi DINDEX,STCNT
|
|
mvi SCBARRAY+11 call bcopy_3
|
|
|
|
mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN|
|
|
# DIRECTION|FIFORESET
|
|
jmp ITloop
|
|
|
|
# Status phase. Wait for the data byte to appear, then read it
|
|
# and store it into the SCB.
|
|
#
|
|
p_status:
|
|
mvi 0xc0 call scsisig # CDO|IOO|!MSGO
|
|
|
|
mvi SCBARRAY+14 call inb_first
|
|
jmp p_mesgin_done
|
|
|
|
# Message out phase. If there is no active message, but the target
|
|
# took us into this phase anyway, build a no-op message and send it.
|
|
#
|
|
p_mesgout:
|
|
mvi 0xa0 call scsisig # CDO|!IOO|MSGO
|
|
mvi 0x8 call mk_mesg # build NOP message
|
|
|
|
clr STCNT+2
|
|
clr STCNT+1
|
|
|
|
# Set up automatic PIO transfer from MSG_START. Bit 3 in
|
|
# SXFRCTL0 (SPIOEN) is already on.
|
|
#
|
|
mvi SINDEX,MSG_START+0
|
|
mov DINDEX,MSG_LEN
|
|
|
|
# When target asks for a byte, drop ATN if it's the last one in
|
|
# the message. Otherwise, keep going until the message is exhausted.
|
|
# (We can't use outb for this since it wants the input in SINDEX.)
|
|
#
|
|
# Keep an eye out for a phase change, in case the target issues
|
|
# a MESSAGE REJECT.
|
|
#
|
|
p_mesgout2:
|
|
test SSTAT0,0x2 jz p_mesgout2 # SPIORDY
|
|
test SSTAT1,0x10 jnz p_mesgout6 # PHASEMIS
|
|
|
|
cmp DINDEX,1 jne p_mesgout3 # last byte?
|
|
mvi CLRSINT1,0x40 # CLRATNO - drop ATN
|
|
|
|
# Write a byte to the SCSI bus. The AIC-7770 refuses to automatically
|
|
# send ACKs in automatic PIO or DMA mode unless you make sure that the
|
|
# "expected" bus phase in SCSISIGO matches the actual bus phase. This
|
|
# behaviour is completely undocumented and caused me several days of
|
|
# grief.
|
|
#
|
|
# After plugging in different drives to test with and using a longer
|
|
# SCSI cable, I found that I/O in Automatic PIO mode ceased to function,
|
|
# especially when transferring >1 byte. It seems to be much more stable
|
|
# if STCNT is set to one before the transfer, and SDONE (in SSTAT0) is
|
|
# polled for transfer completion - for both output _and_ input. The
|
|
# only theory I have is that SPIORDY doesn't drop right away when SCSIDATL
|
|
# is accessed (like the documentation says it does), and that on a longer
|
|
# cable run, the sequencer code was fast enough to loop back and see
|
|
# an SPIORDY that hadn't dropped yet.
|
|
#
|
|
p_mesgout3:
|
|
mvi STCNT+0, 0x01
|
|
mov SCSIDATL,SINDIR
|
|
|
|
p_mesgout4:
|
|
test SSTAT0,0x4 jz p_mesgout4 # SDONE
|
|
dec DINDEX
|
|
test DINDEX,0xff jnz p_mesgout2
|
|
|
|
# If the next bus phase after ATN drops is a message out, it means
|
|
# that the target is requesting that the last message(s) be resent.
|
|
#
|
|
p_mesgout5:
|
|
test SSTAT1,0x8 jnz p_mesgout6 # BUSFREE
|
|
test SSTAT1,0x1 jz p_mesgout5 # REQINIT
|
|
|
|
and A,0xe0,SCSISIGI # CDI|IOI|MSGI
|
|
cmp A,0xa0 jne p_mesgout6
|
|
mvi 0x10 call scsisig # ATNO - re-assert ATN
|
|
|
|
jmp ITloop
|
|
|
|
p_mesgout6:
|
|
mvi CLRSINT1,0x40 # CLRATNO - in case of PHASEMIS
|
|
and FLAGS,0xdf # no active msg
|
|
jmp ITloop
|
|
|
|
# Message in phase. Bytes are read using Automatic PIO mode, but not
|
|
# using inb. This alleviates a race condition, namely that if ATN had
|
|
# to be asserted under Automatic PIO mode, it had to beat the SCSI
|
|
# circuitry sending an ACK to the target. This showed up under heavy
|
|
# loads and really confused things, since ABORT commands wouldn't be
|
|
# seen by the drive after an IDENTIFY message in until it had changed
|
|
# to a data I/O phase.
|
|
#
|
|
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 interpret errors only when they occur
|
|
# instead of always uploading the scb. If the status is SCSI_CHECK,
|
|
# the driver will download a new scb requesting sense, to replace
|
|
# the old one and set the SENSE sequencer flag. If the sense flag is
|
|
# set, the sequencer imediately jumps to start working on the sense
|
|
# command. If the kernel driver does not wish to request sense, it need
|
|
# do nothing, and the command is allowed to complete. 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 check for residuals
|
|
test SCBARRAY+15,0xff jnz resid
|
|
test SCBARRAY+16,0xff jnz resid
|
|
test SCBARRAY+17,0xff jnz resid
|
|
|
|
check_status:
|
|
test SCBARRAY+14,0xff jz status_ok # 0 Status?
|
|
mvi INTSTAT,BAD_STATUS # let driver know
|
|
test FLAGS,SENSE jz status_ok
|
|
jmp p_mesgin_done
|
|
|
|
status_ok:
|
|
# First, mark this target as free.
|
|
test SCBARRAY+0,0x20 jnz complete # Tagged command
|
|
and FUNCTION1,0x70,SCBARRAY+1
|
|
mov A,FUNCTION1
|
|
test SCBARRAY+1,0x88 jz clear_a
|
|
xor ACTIVE_B,A
|
|
jmp complete
|
|
|
|
clear_a:
|
|
xor ACTIVE_A,A
|
|
|
|
complete:
|
|
mov QOUTFIFO,SCBPTR
|
|
mvi INTSTAT,CMDCMPLT
|
|
jmp p_mesgin_done
|
|
|
|
# If we have a residual count, interrupt and tell the host. Other
|
|
# alternatives are to pause the sequencer on all command completes (yuck),
|
|
# dma the resid directly to the host (slick, but a ton of instructions), or
|
|
# have the sequencer pause itself when it encounters a non-zero resid
|
|
# (unecessary pause just to flag the command -- yuck, but takes few instructions
|
|
# and since it shouldn't happen that often is good enough for our purposes).
|
|
|
|
resid:
|
|
mvi INTSTAT,RESIDUAL
|
|
jmp check_status
|
|
|
|
# Is it an extended message? We only support the synchronous and wide data
|
|
# transfer request messages, which will probably be in response to
|
|
# WDTR or SDTR message outs from us. If it's not SDTR or WDTR, reject it -
|
|
# apparently this can be done after any message in byte, according
|
|
# to the SCSI-2 spec.
|
|
#
|
|
p_mesgin1:
|
|
cmp A,1 jne p_mesgin2 # extended message code?
|
|
|
|
mvi ARG_1 call inb_next # extended message length
|
|
mvi A call inb_next # extended message code
|
|
|
|
cmp A,1 je p_mesginSDTR # Syncronous negotiation message
|
|
cmp A,3 je p_mesginWDTR # Wide negotiation message
|
|
jmp p_mesginN
|
|
|
|
p_mesginWDTR:
|
|
cmp ARG_1,2 jne p_mesginN # extended mesg length = 2
|
|
mvi A call inb_next # Width of bus
|
|
mvi INTSTAT,MSG_WDTR # let driver know
|
|
test RETURN_1,0x80 jz p_mesgin_done# Do we need to send WDTR?
|
|
|
|
# We didn't initiate the wide negotiation, so we must respond to the request
|
|
and RETURN_1,0x7f # Clear the SEND_WDTR Flag
|
|
or FLAGS,ACTIVE_MSG
|
|
mvi DINDEX,MSG_START+0
|
|
mvi MSG_START+0 call mk_wdtr # build WDTR message
|
|
or SINDEX,0x10,SIGSTATE # turn on ATNO
|
|
call scsisig
|
|
jmp p_mesgin_done
|
|
|
|
p_mesginSDTR:
|
|
cmp ARG_1,3 jne p_mesginN # extended mesg length = 3
|
|
mvi ARG_1 call inb_next # xfer period
|
|
mvi A call inb_next # REQ/ACK offset
|
|
mvi INTSTAT,MSG_SDTR # call driver to convert
|
|
|
|
test RETURN_1,0x80 jz p_mesgin_done# Do we need to mk_sdtr?
|
|
|
|
or FLAGS,ACTIVE_MSG
|
|
mvi DINDEX, MSG_START+0
|
|
mvi MSG_START+0 call mk_sdtr
|
|
or SINDEX,0x10,SIGSTATE # turn on ATNO
|
|
call scsisig
|
|
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
|
|
|
|
and A,0x07 # lun in lower three bits
|
|
or SAVED_TCL,A,SELID
|
|
and SAVED_TCL,0xf7
|
|
and A,0x08,SBLKCTL # B Channel??
|
|
or SAVED_TCL,A
|
|
call inb_last # ACK
|
|
mov ALLZEROS call findSCB
|
|
setup_SCB:
|
|
and SCBARRAY+0,0xfb # clear disconnect bit in SCB
|
|
or FLAGS,IDENTIFY_SEEN # make note of IDENTIFY
|
|
|
|
call sg_scb2ram # implied restore pointers
|
|
# required on reselect
|
|
jmp ITloop
|
|
get_tag:
|
|
mvi A call inb_first
|
|
cmp A,0x20 jne return # Simple Tag message?
|
|
mvi A call inb_next
|
|
call inb_last
|
|
test A,0xf0 jnz abort_tag # Tag in range?
|
|
mov SCBPTR,A
|
|
mov A,SAVED_TCL
|
|
cmp SCBARRAY+1,A jne abort_tag
|
|
test SCBARRAY+0,TAG_ENB jz abort_tag
|
|
ret
|
|
abort_tag:
|
|
or SINDEX,0x10,SIGSTATE # turn on ATNO
|
|
call scsisig
|
|
mvi INTSTAT,ABORT_TAG # let driver know
|
|
mvi 0xd call mk_mesg # ABORT TAG message
|
|
ret
|
|
|
|
# Message reject? Let the kernel driver handle this. If we have an
|
|
# outstanding WDTR or SDTR negotiation, assume that it's a response from
|
|
# the target selecting 8bit or asynchronous transfer, otherwise just ignore
|
|
# it since we have no clue what it pertains to.
|
|
#
|
|
p_mesgin6:
|
|
cmp A,7 jne p_mesgin7 # message reject code?
|
|
|
|
mvi INTSTAT, MSG_REJECT
|
|
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,SEND_REJECT # 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
|
|
|
|
# Instead of a generic bcopy routine that requires an argument, we unroll
|
|
# the two cases that are actually used, and call them explicitly. This
|
|
# not only reduces the overhead of doing a bcopy by 2/3rds, but ends up
|
|
# saving space in the program since you don't have to put the argument
|
|
# into the accumulator before the call. Both functions expect DINDEX to
|
|
# contain the destination address and SINDEX to contain the source
|
|
# address.
|
|
bcopy_3:
|
|
mov DINDIR,SINDIR
|
|
mov DINDIR,SINDIR
|
|
mov DINDIR,SINDIR ret
|
|
|
|
bcopy_4:
|
|
mov DINDIR,SINDIR
|
|
mov DINDIR,SINDIR
|
|
mov DINDIR,SINDIR
|
|
mov DINDIR,SINDIR ret
|
|
|
|
bcopy_3_dfdat:
|
|
mov DINDIR,DFDAT
|
|
mov DINDIR,DFDAT
|
|
mov DINDIR,DFDAT ret
|
|
|
|
bcopy_4_dfdat:
|
|
mov DINDIR,DFDAT
|
|
mov DINDIR,DFDAT
|
|
mov DINDIR,DFDAT
|
|
mov DINDIR,DFDAT 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 FLAGS,ACTIVE_MSG jnz mk_mesg1 # active message?
|
|
|
|
or FLAGS,ACTIVE_MSG # if not, there is now
|
|
mvi MSG_LEN,1 # length = 1
|
|
mov MSG_START+0,SINDEX # 1-byte message
|
|
|
|
mk_mesg1:
|
|
mvi SEQCTL,0x10 ret # !PAUSEDIS|FASTMODE
|
|
|
|
# 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:
|
|
clr STCNT+2
|
|
clr STCNT+1
|
|
mov DINDEX,SINDEX
|
|
mov DINDIR,SCSIBUSL ret # read byte directly from bus
|
|
|
|
inb_next:
|
|
mov DINDEX,SINDEX # save SINDEX
|
|
|
|
mvi STCNT+0,1 # 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:
|
|
mvi STCNT+0,1 # ACK with dummy read
|
|
mov NONE,SCSIDATL
|
|
inb_last1:
|
|
test SSTAT0,0x4 jz inb_last1 # wait for completion
|
|
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 # !FIFOEMP
|
|
|
|
# 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 DINDEX,SCBARRAY+15
|
|
mvi STCNT call bcopy_3
|
|
|
|
ret
|
|
|
|
dma_finish:
|
|
test DFSTATUS,0x8 jz dma_finish # HDONE
|
|
|
|
clr DFCNTRL # disable DMA
|
|
dma_finish2:
|
|
test DFCNTRL,0x8 jnz dma_finish2 # HDMAENACK
|
|
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:
|
|
and SINDEX,0xf0 # Get target ID
|
|
and A,0x0f,SCSIID
|
|
or SINDEX,A
|
|
mov SCSIID,SINDEX
|
|
|
|
# Esundry initialization.
|
|
#
|
|
clr DROPATN
|
|
clr SIGSTATE
|
|
|
|
# Turn on Automatic PIO mode now, before we expect to see a 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.
|
|
#
|
|
mvi SXFRCTL0,0x8a # DFON|SPIOEN|CLRCHN
|
|
|
|
# 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_dtr
|
|
mov SCSIRATE,SINDIR ret
|
|
|
|
# Assert that if we've been reselected, then we've seen an IDENTIFY
|
|
# message.
|
|
#
|
|
assert:
|
|
test FLAGS,RESELECTED jz return # reselected?
|
|
test FLAGS,IDENTIFY_SEEN jnz return # seen IDENTIFY?
|
|
|
|
mvi INTSTAT,NO_IDENT ret # no - cause a kernel panic
|
|
|
|
# Find out if disconnection is ok from the information the BIOS has left
|
|
# us. The tcl from SCBARRAY+1 should be in SINDEX; A will
|
|
# contain either 0x40 (disconnection ok) or 0x00 (disconnection not ok)
|
|
# on exit.
|
|
#
|
|
# To allow for wide or twin busses, we check the upper bit of the target ID
|
|
# and the channel ID and look at the appropriate disconnect register.
|
|
#
|
|
disconnect:
|
|
and FUNCTION1,0x70,SINDEX # strip off extra just in case
|
|
mov A,FUNCTION1
|
|
test SINDEX, 0x88 jz disconnect_a
|
|
|
|
test DISC_DSB_B,A jz disconnect1 # bit nonzero if DISabled
|
|
clr A ret
|
|
|
|
disconnect_a:
|
|
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/channel/lun in SAVED_TCL 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. SINDEX should be
|
|
# cleared on call.
|
|
#
|
|
findSCB:
|
|
mov A,SAVED_TCL
|
|
mov SCBPTR,SINDEX # switch to new SCB
|
|
cmp SCBARRAY+1,A jne findSCB1 # target ID/channel/lun match?
|
|
test SCBARRAY+0,0x4 jz findSCB1 # should be disconnected
|
|
test SCBARRAY+0,TAG_ENB jnz get_tag
|
|
ret
|
|
|
|
findSCB1:
|
|
inc SINDEX
|
|
mov A,SCBCOUNT
|
|
cmp SINDEX,A jne findSCB
|
|
|
|
mvi INTSTAT,NO_MATCH # 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 DINDEX,SG_NEXT
|
|
mvi SCBARRAY+3 call bcopy_4
|
|
|
|
mvi SG_NOLOAD,0x80
|
|
test SCBARRAY+0,0x10 jnz return # don't reload s/g?
|
|
clr SG_NOLOAD ret
|
|
|
|
# Copying RAM values back to SCB, for Save Data Pointers message.
|
|
#
|
|
sg_ram2scb:
|
|
mov SCBARRAY+2,SG_COUNT
|
|
|
|
mvi DINDEX,SCBARRAY+3
|
|
mvi SG_NEXT call bcopy_4
|
|
|
|
and SCBARRAY+0,0xef,SCBARRAY+0
|
|
test SG_NOLOAD,0x80 jz return # reload s/g?
|
|
or SCBARRAY+0,SG_LOAD 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 return # SG being used?
|
|
test SG_NOLOAD,0x80 jnz return # don't reload s/g?
|
|
|
|
clr HCNT+2
|
|
clr HCNT+1
|
|
mvi HCNT+0,SG_SIZEOF
|
|
|
|
mvi DINDEX,HADDR
|
|
mvi SG_NEXT call bcopy_4
|
|
|
|
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.
|
|
#
|
|
|
|
call dma_finish
|
|
|
|
# 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 entry is only 8 bytes.
|
|
#
|
|
# struct ahc_dma_seg {
|
|
# physaddr addr; /* four bytes, little-endian order */
|
|
# long len; /* four bytes, little endian order */
|
|
# };
|
|
#
|
|
|
|
mvi DINDEX, SCBARRAY+19
|
|
call bcopy_4_dfdat
|
|
|
|
# For Linux, we must throw away four bytes since there is a 32bit gap
|
|
# in the middle of a struct scatterlist
|
|
# mov NONE,DFDAT
|
|
# mov NONE,DFDAT
|
|
# mov NONE,DFDAT
|
|
# mov NONE,DFDAT
|
|
|
|
call bcopy_3_dfdat #Only support 24 bit length.
|
|
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 return # 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 ret # don't reload s/g next time
|
|
|
|
# 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_dtr:
|
|
shr A,SCSIID,4
|
|
test SBLKCTL,0x08 jz ndx_dtr_2
|
|
or A,0x08 # Channel B entries add 8
|
|
ndx_dtr_2:
|
|
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 WDTR or SDTR message
|
|
# starting at the address passed in SINDEX. DINDEX is modified on return.
|
|
# The SCSI-II spec requires that Wide negotiation occur first and you can
|
|
# only negotiat one or the other at a time otherwise in the event of a message
|
|
# reject, you wouldn't be able to tell which message was the culpret.
|
|
#
|
|
mk_dtr:
|
|
test SCBARRAY+0,0xc0 jz return # NEEDWDTR|NEEDSDTR
|
|
test SCBARRAY+0,NEEDWDTR jnz mk_wdtr_16bit
|
|
or FLAGS, MAX_SYNC # Force an offset of 15
|
|
|
|
mk_sdtr:
|
|
mvi DINDIR,1 # extended message
|
|
mvi DINDIR,3 # extended message length = 3
|
|
mvi DINDIR,1 # SDTR code
|
|
call sdtr_to_rate
|
|
mov DINDIR,RETURN_1 # REQ/ACK transfer period
|
|
test FLAGS, MAX_SYNC jnz mk_sdtr_max_sync
|
|
and DINDIR,0xf,SINDIR # Sync Offset
|
|
|
|
mk_sdtr_done:
|
|
add MSG_LEN,-MSG_START+0,DINDEX ret # update message length
|
|
|
|
mk_sdtr_max_sync:
|
|
# We're initiating sync negotiation, so request the max offset we can (15)
|
|
mvi DINDIR, 0x0f
|
|
xor FLAGS, MAX_SYNC
|
|
jmp mk_sdtr_done
|
|
|
|
mk_wdtr_16bit:
|
|
mvi ARG_1,BUS_16_BIT
|
|
mk_wdtr:
|
|
mvi DINDIR,1 # extended message
|
|
mvi DINDIR,2 # extended message length = 2
|
|
mvi DINDIR,3 # WDTR code
|
|
mov DINDIR,ARG_1 # bus width
|
|
|
|
add MSG_LEN,-MSG_START+0,DINDEX ret # update message length
|
|
|
|
# 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
|
|
|
|
sdtr_to_rate:
|
|
call ndx_dtr # index scratch space for target
|
|
shr A,SINDIR,0x4
|
|
dec SINDEX #Preserve SINDEX
|
|
and A,0x7
|
|
clr RETURN_1
|
|
sdtr_to_rate_loop:
|
|
test A,0x0f jz sdtr_to_rate_done
|
|
add RETURN_1,0x18
|
|
dec A
|
|
jmp sdtr_to_rate_loop
|
|
sdtr_to_rate_done:
|
|
shr RETURN_1,0x2
|
|
add RETURN_1,0x18 ret
|
|
|
|
return:
|
|
ret
|