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Diffstat (limited to 'sys/gnu/misc/aha274x.seq')
| -rw-r--r-- | sys/gnu/misc/aha274x.seq | 1064 |
1 files changed, 0 insertions, 1064 deletions
diff --git a/sys/gnu/misc/aha274x.seq b/sys/gnu/misc/aha274x.seq deleted file mode 100644 index 9b83b84..0000000 --- a/sys/gnu/misc/aha274x.seq +++ /dev/null @@ -1,1064 +0,0 @@ -# @(#)aic7xxx.seq 1.30 94/11/09 jda -# -# Adaptec 274x device driver for Linux. -# Copyright (c) 1994 The University of Calgary Department of Computer Science. -# -# This program is free software; you can redistribute it and/or modify -# it under the terms of the GNU General Public License as published by -# the Free Software Foundation; either version 2 of the License, or -# (at your option) any later version. -# -# This program is distributed in the hope that it will be useful, -# but WITHOUT ANY WARRANTY; without even the implied warranty of -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -# GNU General Public License for more details. -# -# You should have received a copy of the GNU General Public License -# along with this program; if not, write to the Free Software -# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - -VERSION AIC7XXX_SEQ_VERSION 1.30 - -MAXSCB-1 = 0xf - -SCSISEQ = 0x00 -SXFRCTL0 = 0x01 -SXFRCTL1 = 0x02 -SCSISIGI = 0x03 -SCSISIGO = 0x03 -SCSIRATE = 0x04 -SCSIID = 0x05 -SCSIDATL = 0x06 -STCNT = 0x08 -STCNT+0 = 0x08 -STCNT+1 = 0x09 -STCNT+2 = 0x0a -SSTAT0 = 0x0b -CLRSINT1 = 0x0c -SSTAT1 = 0x0c -SIMODE1 = 0x11 -SCSIBUSL = 0x12 -SHADDR = 0x14 -SELID = 0x19 -SBLKCTL = 0x1f -SEQCTL = 0x60 -A = 0x64 # == ACCUM -SINDEX = 0x65 -DINDEX = 0x66 -ALLZEROS = 0x6a -NONE = 0x6a -SINDIR = 0x6c -DINDIR = 0x6d -FUNCTION1 = 0x6e -HADDR = 0x88 -HCNT = 0x8c -HCNT+0 = 0x8c -HCNT+1 = 0x8d -HCNT+2 = 0x8e -SCBPTR = 0x90 -INTSTAT = 0x91 -DFCNTRL = 0x93 -DFSTATUS = 0x94 -DFDAT = 0x99 -QINFIFO = 0x9b -QINCNT = 0x9c -QOUTFIFO = 0x9d - -SCSICONF = 0x5a - -# The two reserved bytes at SCBARRAY+1[23] are expected to be set to -# zero, and the reserved bit in SCBARRAY+0 is used as an internal flag -# to indicate whether or not to reload scatter-gather parameters after -# a disconnect. -# -SCBARRAY+0 = 0xa0 -SCBARRAY+1 = 0xa1 -SCBARRAY+2 = 0xa2 -SCBARRAY+3 = 0xa3 -SCBARRAY+7 = 0xa7 -SCBARRAY+11 = 0xab -SCBARRAY+14 = 0xae -SCBARRAY+15 = 0xaf -SCBARRAY+16 = 0xb0 -SCBARRAY+17 = 0xb1 -SCBARRAY+18 = 0xb2 -SCBARRAY+19 = 0xb3 -SCBARRAY+20 = 0xb4 -SCBARRAY+21 = 0xb5 -SCBARRAY+22 = 0xb6 -SCBARRAY+23 = 0xb7 -SCBARRAY+24 = 0xb8 -SCBARRAY+25 = 0xb9 - -SIGNAL_0 = 0x01 # unknown scsi bus phase -SIGNAL_1 = 0x11 # message reject -SIGNAL_2 = 0x21 # no IDENTIFY after reconnect -SIGNAL_3 = 0x31 # no cmd match for reconnect -SIGNAL_4 = 0x41 # SDTR -> SCSIRATE conversion -STATUS_ERROR = 0x51 - -# The host adapter card (at least the BIOS) uses 20-2f for SCSI -# device information, 32-33 and 5a-5f as well. Since we don't support -# wide or twin-bus SCSI, 28-2f can be reclaimed. As it turns out, the -# BIOS trashes 20-27 anyway, writing the synchronous negotiation results -# on top of the BIOS values, so we re-use those for our per-target -# scratchspace (actually a value that can be copied directly into -# SCSIRATE). This implies, since we can't get the BIOS config values, -# that all targets will be negotiated with for synchronous transfer. -# NEEDSDTR has one bit per target indicating if an SDTR message is -# needed for that device - this will be set initially, as well as -# after a bus reset condition. -# -# The high bit of DROPATN is set if ATN should be dropped before the ACK -# when outb is called. REJBYTE contains the first byte of a MESSAGE IN -# message, so the driver can report an intelligible error if a message is -# rejected. -# -# RESELECT's high bit is true if we are currently handling a reselect; -# its next-highest bit is true ONLY IF we've seen an IDENTIFY message -# from the reselecting target. If we haven't had IDENTIFY, then we have -# no idea what the lun is, and we can't select the right SCB register -# bank, so force a kernel panic if the target attempts a data in/out or -# command phase instead of corrupting something. -# -# Note that SG_NEXT occupies four bytes. -# -SYNCNEG = 0x20 -DISC_DSB_A = 0x32 - -DROPATN = 0x30 -REJBYTE = 0x31 -RESELECT = 0x34 - -MSG_FLAGS = 0x35 -MSG_LEN = 0x36 -MSG_START+0 = 0x37 -MSG_START+1 = 0x38 -MSG_START+2 = 0x39 -MSG_START+3 = 0x3a -MSG_START+4 = 0x3b -MSG_START+5 = 0x3c --MSG_START+0 = 0xc9 # 2's complement of MSG_START+0 - -ARG_1 = 0x4c # sdtr conversion args & return -ARG_2 = 0x4d -RETURN_1 = 0x4c - -SIGSTATE = 0x4e # value written to SCSISIGO -NEEDSDTR = 0x4f # send SDTR message, 1 bit/trgt - -SG_SIZEOF = 0x8 # sizeof(struct scatterlist) -SG_NOLOAD = 0x50 # load SG pointer/length? -SG_COUNT = 0x51 # working value of SG count -SG_NEXT = 0x52 # working value of SG pointer -SG_NEXT+0 = 0x52 -SG_NEXT+1 = 0x53 -SG_NEXT+2 = 0x54 -SG_NEXT+3 = 0x55 - -SCBCOUNT = 0x56 # the actual number of SCBs -ACTIVE_A = 0x57 - -# Poll QINCNT for work - the lower three bits contain -# the number of entries in the Queue In FIFO. -# -start: - test SCSISIGI,0x4 jnz reselect # BSYI - test QINCNT,MAXSCB-1 jz start - -# We have at least one queued SCB now. Set the SCB pointer -# from the FIFO so we see the right bank of SCB registers, -# then set SCSI options and set the initiator and target -# SCSI IDs. -# - mov SCBPTR,QINFIFO - -# See if there is not already an active SCB for this target. This code -# will have to be modified when we add support for dual and wide busses. - - and FUNCTION1,0x70,SCBARRAY+1 - mov A,FUNCTION1 - test ACTIVE_A,A jz active -# Place the currently active back on the queue for later processing - mov QINFIFO, SCBPTR - jmp start - -# Mark the current target as busy and get working on the SCB -active: - or ACTIVE_A,A - mov SCBARRAY+1 call initialize - clr SG_NOLOAD - clr RESELECT - -# As soon as we get a successful selection, the target should go -# into the message out phase since we have ATN asserted. Prepare -# the message to send, locking out the device driver. If the device -# driver hasn't beaten us with an ABORT or RESET message, then tack -# on a SDTR negotation if required. -# -# Messages are stored in scratch RAM starting with a flag byte (high bit -# set means active message), one length byte, and then the message itself. -# - mov SCBARRAY+1 call disconnect # disconnect ok? - - and SINDEX,0x7,SCBARRAY+1 # lun - or SINDEX,A # return value from disconnect - or SINDEX,0x80 call mk_mesg # IDENTIFY message - - mov A,SINDEX - cmp MSG_START+0,A jne !message # did driver beat us? - mvi MSG_START+1 call mk_sdtr # build SDTR message if needed - -!message: - -# Enable selection phase as an initiator, and do automatic ATN -# after the selection. -# - mvi SCSISEQ,0x48 # ENSELO|ENAUTOATNO - -# Wait for successful arbitration. The AIC-7770 documentation says -# that SELINGO indicates successful arbitration, and that it should -# be used to look for SELDO. However, if the sequencer is paused at -# just the right time - a parallel fsck(8) on two drives did it for -# me - then SELINGO can flip back to false before we've seen it. This -# makes the sequencer sit in the arbitration loop forever. This is -# Not Good. -# -# Therefore, I've added a check in the arbitration loop for SELDO -# too. This could arguably be made a critical section by disabling -# pauses, but I don't want to make a potentially infinite loop a CS. -# I suppose you could fold it into the select loop, too, but since -# I've been hunting this bug for four days it's kinda like a trophy. -# -arbitrate: - test SSTAT0,0x40 jnz *select # SELDO - test SSTAT0,0x10 jz arbitrate # SELINGO - -# Wait for a successful selection. If the hardware selection -# timer goes off, then the driver gets the interrupt, so we don't -# need to worry about it. -# -select: - test SSTAT0,0x40 jz select # SELDO - jmp *select - -# Reselection is being initiated by a target - we've seen the BSY -# line driven active, and we didn't do it! Enable the reselection -# hardware, and wait for it to finish. Make a note that we've been -# reselected, but haven't seen an IDENTIFY message from the target -# yet. -# -reselect: - mvi SCSISEQ,0x10 # ENRSELI - -reselect1: - test SSTAT0,0x20 jz reselect1 # SELDI - mov SELID call initialize - - mvi RESELECT,0x80 # reselected, no IDENTIFY - -# After the [re]selection, make sure that the [re]selection enable -# bit is off. This chip is flaky enough without extra things -# turned on. Also clear the BUSFREE bit in SSTAT1 since we'll be -# using it shortly. -# -*select: - clr SCSISEQ - mvi CLRSINT1,0x8 # CLRBUSFREE - -# Main loop for information transfer phases. If BSY is false, then -# we have a bus free condition, expected or not. Otherwise, wait -# for the target to assert REQ before checking MSG, C/D and I/O -# for the bus phase. -# -# We can't simply look at the values of SCSISIGI here (if we want -# to do synchronous data transfer), because the target won't assert -# REQ if it's already sent us some data that we haven't acknowledged -# yet. -# -ITloop: - test SSTAT1,0x8 jnz p_busfree # BUSFREE - test SSTAT1,0x1 jz ITloop # REQINIT - - and A,0xe0,SCSISIGI # CDI|IOI|MSGI - - cmp ALLZEROS,A je p_dataout - cmp A,0x40 je p_datain - cmp A,0x80 je p_command - cmp A,0xc0 je p_status - cmp A,0xa0 je p_mesgout - cmp A,0xe0 je p_mesgin - - mvi INTSTAT,SIGNAL_0 # unknown - signal driver - -p_dataout: - mvi 0 call scsisig # !CDO|!IOO|!MSGO - call assert - call sg_load - - mvi A,3 - mvi DINDEX,HCNT - mvi SCBARRAY+23 call bcopy - - mvi A,3 - mvi DINDEX,STCNT - mvi SCBARRAY+23 call bcopy - - mvi A,4 - mvi DINDEX,HADDR - mvi SCBARRAY+19 call bcopy - - mvi 0x3d call dma # SCSIEN|SDMAEN|HDMAEN| - # DIRECTION|FIFORESET - -# After a DMA finishes, save the final transfer pointer and count -# back into the SCB, in case a device disconnects in the middle of -# a transfer. Use SHADDR and STCNT instead of HADDR and HCNT, since -# it's a reflection of how many bytes were transferred on the SCSI -# (as opposed to the host) bus. -# - mvi A,3 - mvi DINDEX,SCBARRAY+23 - mvi STCNT call bcopy - - mvi A,4 - mvi DINDEX,SCBARRAY+19 - mvi SHADDR call bcopy - - call sg_advance - mov SCBARRAY+18,SG_COUNT # residual S/G count - - jmp ITloop - -p_datain: - mvi 0x40 call scsisig # !CDO|IOO|!MSGO - call assert - call sg_load - - mvi A,3 - mvi DINDEX,HCNT - mvi SCBARRAY+23 call bcopy - - mvi A,3 - mvi DINDEX,STCNT - mvi SCBARRAY+23 call bcopy - - mvi A,4 - mvi DINDEX,HADDR - mvi SCBARRAY+19 call bcopy - - mvi 0x39 call dma # SCSIEN|SDMAEN|HDMAEN| - # !DIRECTION|FIFORESET - mvi A,3 - mvi DINDEX,SCBARRAY+23 - mvi STCNT call bcopy - - mvi A,4 - mvi DINDEX,SCBARRAY+19 - mvi SHADDR call bcopy - - 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 A,3 - mvi DINDEX,HCNT - mvi SCBARRAY+11 call bcopy - - mvi A,3 - mvi DINDEX,STCNT - mvi SCBARRAY+11 call bcopy - - mvi A,4 - mvi DINDEX,HADDR - mvi SCBARRAY+7 call bcopy - - 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 - jmp ITloop - -# 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 - -# 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 - clr A - -# 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: - call one_stcnt - mov SCSIDATL,SINDIR - -p_mesgout4: - test SSTAT0,0x4 jz p_mesgout4 # SDONE - dec DINDEX - inc A - cmp MSG_LEN,A jne 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 - clr MSG_FLAGS # 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 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,0x40 # PAUSEDIS - 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: - clr SEQCTL # !PAUSEDIS - 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, flush the data FIFO. -# -dma3: - test SINDEX,0x4 jnz dma5 # DIRECTION - and SINDEX,0xfe # mask out FIFORESET - or DFCNTRL,0x2,SINDEX # FIFOFLUSH -dma4: - test DFCNTRL,0x2 jnz 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. -# - mvi SXFRCTL0,0xa # 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. -# - and A,0x38,SCSICONF # PARITY_ENB_A|SEL_TIM_A[10] - or SXFRCTL1,0x4,A # ENSTIMER - 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 (diconnection 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 -# 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 SCBPTR,SINDEX # switch to new SCB - mov A,DINDEX - 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 - |
