/*+M*********************************************************************** *Adaptec 274x/284x/294x device driver for Linux and FreeBSD. * *Copyright (c) 1994 John Aycock * The University of Calgary Department of Computer Science. * All rights reserved. * *Modifications/enhancements: * Copyright (c) 1994, 1995 Justin Gibbs. All rights reserved. * *Redistribution and use in source and binary forms, with or without *modification, are permitted provided that the following conditions *are met: *1. Redistributions of source code must retain the above copyright * notice, this list of conditions, and the following disclaimer. *2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. *3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of Calgary * Department of Computer Science and its contributors. *4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * *THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND *ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE *IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE *ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE *FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL *DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS *OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) *HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT *LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY *OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF *SUCH DAMAGE. * *FreeBSD, Twin, Wide, 2 command per target support, tagged queuing and other *optimizations provided by Justin T. Gibbs (gibbs@FreeBSD.org) * *-M************************************************************************/ VERSION AIC7XXX_SEQ_VER "$Id: aic7xxx.seq,v 1.26 1996/01/05 16:11:49 gibbs Exp $" #include "../../dev/aic7xxx/aic7xxx_reg.h" /* * We can't just use ACCUM in the sequencer code because it * must be treated specially by the assembler, and it currently * looks for the symbol 'A'. This is the only register defined * the assembler's symbol space. */ A = ACCUM /* After starting the selection hardware, we return to the "poll_for_work" * loop so that we can check for reconnecting targets as well as for our * selection to complete just in case the reselection wins bus arbitration. * The problem with this is that we must keep track of the SCB that we've * already pulled from the QINFIFO and started the selection on just in case * the reselection wins so that we can retry the selection at a later time. * This problem cannot be resolved by holding a single entry in scratch * ram since a reconnecting target can request sense and this will create * yet another SCB waiting for selection. The solution used here is to * use byte 31 of the SCB as a psuedo-next pointer and to thread a list * of SCBs that are awaiting selection. Since 0-0xfe are valid SCB offsets, * SCB_LIST_NULL is 0xff which is out of range. The kernel driver must * add an entry to this list everytime a request sense occurs. The sequencer * will automatically consume the entries. */ /* * Initialize any state idle loop state here. This code is executed on * startup and after every bus free. */ start: mvi SCSISEQ,ENRSELI /* Always allow reselection */ poll_for_work: /* * Are we a twin channel device? * For fairness, we check the other bus first, * since we just finished a transaction on the * current channel. */ test FLAGS,TWIN_BUS jz start2 xor SBLKCTL,SELBUSB /* Toggle to the other bus */ test SSTAT0,SELDI jnz reselect xor SBLKCTL,SELBUSB /* Toggle to the original bus */ start2: test SSTAT0,SELDI jnz reselect cmp WAITING_SCBH,SCB_LIST_NULL jne start_waiting test QINCNT,0xff jz poll_for_work /* We have at least one queued SCB now and we don't have any * SCBs in the list of SCBs awaiting selection. Set the SCB * pointer from the FIFO so we see the right bank of SCB * registers. */ mov SCBPTR,QINFIFO /* * If the control byte of this SCB has the NEEDDMA flag set, we have * yet to DMA it from host memory */ test SCB_CONTROL,NEEDDMA jz test_busy clr HCNT2 clr HCNT1 mvi HCNT0,SCB_SIZEOF mvi DINDEX,HADDR mvi SCB_PHYSADDR 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 the SCB from the FIFO to the SCBARRAY */ mvi DINDEX, SCBARRAY call bcopy_5_dfdat call bcopy_7_dfdat call bcopy_7_dfdat call bcopy_7_dfdat /* * See if there is not already an active SCB for this target. This code * locks out on a per target basis instead of target/lun. Although this * is not ideal for devices that have multiple luns active at the same * time, it is faster than looping through all SCB's looking for active * commands. It may be benificial to make findscb a more general procedure * to see if the added cost of the search is negligible. This code also * assumes that the kernel driver will clear the active flags on board * initialization, board reset, and a target SELTO. Tagged commands * don't set the active bits since you can have more than queue more * than one command at a time. We do, however, look to see if there * are any non-tagged I/Os in progress, and requeue the command if * there are. Tagged and non-tagged commands cannot be mixed to a * single target. */ test_busy: mov FUNCTION1,SCB_TCL mov A,FUNCTION1 test SCB_TCL,0x88 jz test_a /* Id < 8 && A channel */ test ACTIVE_B,A jnz requeue test SCB_CONTROL,TAG_ENB jnz start_scb /* Mark the current target as busy */ or ACTIVE_B,A jmp start_scb /* Place the currently active SCB back on the queue for later processing */ requeue: mov QINFIFO, SCBPTR jmp poll_for_work /* * Pull the first entry off of the waiting for selection list * We don't have to "test_busy" because only transactions that * have passed that test can be in the waiting_scb list. */ start_waiting: mov SCBPTR,WAITING_SCBH jmp start_scb2 test_a: test ACTIVE_A,A jnz requeue test SCB_CONTROL,TAG_ENB jnz start_scb /* Mark the current target as busy */ or ACTIVE_A,A start_scb: mov SCB_NEXT_WAITING,WAITING_SCBH mov WAITING_SCBH, SCBPTR start_scb2: and SINDEX,0xf7,SBLKCTL /* Clear the channel select bit */ and A,0x08,SCB_TCL /* Get new channel bit */ or SINDEX,A mov SBLKCTL,SINDEX /* select channel */ mov SCB_TCL call initialize_scsiid /* * Enable selection phase as an initiator, and do automatic ATN * after the selection. We do this now so that we can overlap the * rest of our work to set up this target with the arbitration and * selection bus phases. */ start_selection: mvi SCSISEQ,0x58 /* ENSELO|ENAUTOATNO|ENRSELI */ /* * 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. * * Messages are stored in scratch RAM starting with a length byte * followed by the message itself. */ test SCB_CMDLEN,0xff jnz mk_identify /* 0 Length Command? */ /* * The kernel has sent us an SCB with no command attached. This implies * that the kernel wants to send a message of some sort to this target, * so we interrupt the driver, allow it to fill the message buffer, and * then go back into the arbitration loop */ mvi INTSTAT,AWAITING_MSG jmp wait_for_selection mk_identify: and A,DISCENB,SCB_CONTROL /* mask off disconnect privledge */ and SINDEX,0x7,SCB_TCL /* lun */ or SINDEX,A /* or in disconnect privledge */ or SINDEX,MSG_IDENTIFY call mk_mesg /* IDENTIFY message */ test SCB_CONTROL,0xb0 jz !message /* WDTR, SDTR or TAG?? */ /* * Tag Message if Tag enabled in SCB control block. Use SCBPTR as the tag * value */ mk_tag: mvi DINDEX, MSG1 test SCB_CONTROL,TAG_ENB jz mk_tag_done and A,0x23,SCB_CONTROL mov DINDIR,A mov DINDIR,SCBPTR add MSG_LEN,COMP_MSG0,DINDEX /* update message length */ mk_tag_done: mov DINDEX call mk_dtr /* build DTR message if needed */ !message: wait_for_selection: test SSTAT0,SELDO jnz select test SSTAT0,SELDI jz wait_for_selection /* * Reselection has been initiated by a target. Make a note that we've been * reselected, but haven't seen an IDENTIFY message from the target * yet. */ reselect: clr MSG_LEN /* Don't have anything in the mesg buffer */ mov SELID call initialize_scsiid mvi SAVED_TCL, 0xff /* * Fill with an imposible value so we * don't get false hits for a tag * without an identify. */ and FLAGS,0x03 /* clear target specific flags */ or FLAGS,RESELECTED jmp select2 /* * After the selection, remove this SCB from the "waiting for selection" * list. This is achieved by simply moving our "next" pointer into * WAITING_SCBH. Our next pointer will be set to null the next time this * SCB is used, so don't bother with it now. */ select: and FLAGS,0x03 /* Clear target flags */ or SCB_CONTROL,NEEDDMA /* * Some drives will issue a simple tag message during * a tagged selection if they are immediately ready * to handle the command without a disconnect. Ensure * that SAVED_TCL (used in get_tag) is inialized correctly * during a selection for this reason. */ mov SAVED_TCL, SCB_TCL mov WAITING_SCBH,SCB_NEXT_WAITING select2: /* * 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. */ clr SIGSTATE or SXFRCTL0,CLRCHN /* * Initialize SCSIRATE with the appropriate value for this target. */ call ndx_dtr mov SCSIRATE,SINDIR mvi SCSISEQ,ENAUTOATNP /* * ATN on parity errors * for "in" phases */ mvi CLRSINT1,CLRBUSFREE mvi CLRSINT0,0x60 /* CLRSELDI|CLRSELDO */ /* * 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. * */ ITloop: test SSTAT1,BUSFREE jnz p_busfree test SSTAT1,REQINIT jz ITloop and A,PHASE_MASK,SCSISIGI mov A call scsisig cmp ALLZEROS,A je p_dataout cmp A,P_DATAIN je p_datain cmp A,P_COMMAND je p_command cmp A,P_MESGOUT je p_mesgout cmp A,P_STATUS je p_status cmp A,P_MESGIN je p_mesgin mvi INTSTAT,BAD_PHASE /* unknown phase - signal driver */ p_dataout: mvi DMAPARAMS,0x7d /* * WIDEODD|SCSIEN|SDMAEN|HDMAEN| * DIRECTION|FIFORESET */ jmp data_phase_init /* * If we re-enter the data phase after going through another phase, the * STCNT may have been cleared, so restore it from the residual field. */ data_phase_reinit: mvi DINDEX, STCNT mvi SCB_RESID_DCNT call bcopy_3 jmp data_phase_loop p_datain: mvi DMAPARAMS,0x79 /* * WIDEODD|SCSIEN|SDMAEN|HDMAEN| * !DIRECTION|FIFORESET */ data_phase_init: call assert test FLAGS, DPHASE jnz data_phase_reinit call sg_scb2ram or FLAGS, DPHASE /* We have seen a data phase */ data_phase_loop: /* If we are the last SG block, don't set wideodd. */ cmp SG_COUNT,0x01 jne data_phase_wideodd and DMAPARAMS, 0xbf /* Turn off WIDEODD */ data_phase_wideodd: mov DMAPARAMS call dma /* Exit if we had an underrun */ test SSTAT0,SDONE jz data_phase_finish /* underrun STCNT != 0 */ /* * Advance the scatter-gather pointers if needed */ sg_advance: dec SG_COUNT /* one less segment to go */ test SG_COUNT, 0xff jz data_phase_finish /* Are we done? */ clr A /* add sizeof(struct scatter) */ add SG_NEXT0,SG_SIZEOF,SG_NEXT0 adc SG_NEXT1,A,SG_NEXT1 adc SG_NEXT2,A,SG_NEXT2 adc SG_NEXT3,A,SG_NEXT3 /* * Load a struct scatter and set up the data address and length. * If the working value of the SG count is nonzero, then * we need to load a new set of values. * * This, like all DMA's, assumes a little-endian host data storage. */ sg_load: clr HCNT2 clr HCNT1 mvi HCNT0,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 * }; */ /* * For Linux, we must throw away four bytes since there is a 32bit gap * in the middle of a struct scatterlist */ #ifdef LINUX call bcopy_4_dfdat mov NONE,DFDAT mov NONE,DFDAT mov NONE,DFDAT mov NONE,DFDAT call bcopy_3_dfdat /* Only support 24 bit length. */ #else /* * For FreeBSD, just copy it wholesale */ mvi DINDEX,HADDR call bcopy_7_dfdat #endif /* Load STCNT as well. It is a mirror of HCNT */ mvi DINDEX,STCNT mvi HCNT call bcopy_3 test SSTAT1,PHASEMIS jz data_phase_loop data_phase_finish: /* * After a DMA finishes, save the SG and STCNT residuals back into the SCB * We use STCNT instead of HCNT, since it's a reflection of how many bytes * were transferred on the SCSI (as opposed to the host) bus. */ mvi DINDEX,SCB_RESID_DCNT mvi STCNT call bcopy_3 mov SCB_RESID_SGCNT, SG_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: call assert /* * Load HADDR and HCNT. We can do this in one bcopy since they are neighbors */ mvi DINDEX,HADDR mvi SCB_CMDPTR call bcopy_7 mvi DINDEX,STCNT mvi SCB_CMDLEN 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 SCB_TARGET_STATUS call inb_first jmp 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: test MSG_LEN, 0xff jnz p_mesgout_start mvi MSG_NOP call mk_mesg /* build NOP message */ p_mesgout_start: /* * Set up automatic PIO transfer from MSG0. Bit 3 in * SXFRCTL0 (SPIOEN) is already on. */ mvi SINDEX,MSG0 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. * * Keep an eye out for a phase change, in case the target issues * a MESSAGE REJECT. */ p_mesgout_loop: test SSTAT1,PHASEMIS jnz p_mesgout_phasemis test SSTAT0,SPIORDY jz p_mesgout_loop cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ mvi CLRSINT1,CLRATNO /* drop ATN */ p_mesgout_outb: or SXFRCTL0, CLRSTCNT mvi STCNT0, 1 dec DINDEX mov SCSIDATL,SINDIR p_mesgout_outb_wait: test SSTAT0,SDONE jz p_mesgout_outb_wait p_mesgout4: test DINDEX,0xff jnz p_mesgout_loop /* * 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_mesgout_snoop: test SSTAT1,BUSFREE jnz p_mesgout_done test SSTAT1,REQINIT jz p_mesgout_snoop test SSTAT1,PHASEMIS jnz p_mesgout_done or SINDEX,0x10,SIGSTATE /* turn on ATNO */ call scsisig /* ATNO - re-assert ATN */ jmp ITloop p_mesgout_phasemis: mvi CLRSINT1,CLRATNO /* Be sure turn ATNO off */ p_mesgout_done: clr MSG_LEN /* no active msg */ jmp ITloop /* * Message in phase. Bytes are read using Automatic PIO mode. */ p_mesgin: mvi A call inb_first /* read the 1st message byte */ mov REJBYTE,A /* save it for the driver */ test A,MSG_IDENTIFY jnz mesgin_identify cmp A,MSG_DISCONNECT je mesgin_disconnect cmp A,MSG_SDPTRS je mesgin_sdptrs cmp ALLZEROS,A je mesgin_complete cmp A,MSG_RDPTRS je mesgin_rdptrs cmp A,MSG_EXTENDED je mesgin_extended cmp A,MSG_REJECT je mesgin_reject rej_mesgin: /* * 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. */ or SINDEX,0x10,SIGSTATE /* turn on ATNO */ call scsisig mvi INTSTAT,SEND_REJECT /* let driver know */ mvi MSG_REJECT call mk_mesg mesgin_done: call inb_last /*ack & turn auto PIO back on*/ jmp ITloop mesgin_complete: /* * 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, modify the "waiting for selection" SCB list and set * RETURN_1 to 0x80. If RETURN_1 is set to 0x80 the sequencer imediately * jumps to main loop where it will run down the waiting SCB list. * If the kernel driver does not wish to request sense, it need * only clear RETURN_1, 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 SCB_RESID_SGCNT,0xff jz check_status /* * 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, we may have space to do it now) * or have the sequencer pause itself when it encounters a non-zero resid * (unecessary pause just to flag the command -yuck-, but takes one instruction * and since it shouldn't happen that often is good enough for our purposes). */ resid: mvi INTSTAT,RESIDUAL check_status: test SCB_TARGET_STATUS,0xff jz status_ok /* Good Status? */ mvi INTSTAT,BAD_STATUS /* let driver know */ cmp RETURN_1, SEND_SENSE jne status_ok jmp mesgin_done status_ok: /* First, mark this target as free. */ test SCB_CONTROL,TAG_ENB jnz test_immediate /* * Tagged commands * don't busy the * target. */ mov FUNCTION1,SCB_TCL mov A,FUNCTION1 test SCB_TCL,0x88 jz clear_a xor ACTIVE_B,A jmp test_immediate clear_a: xor ACTIVE_A,A test_immediate: test SCB_CMDLEN,0xff jnz complete /* Immediate message complete */ /* * Pause the sequencer until the driver gets around to handling the command * complete. This is so that any action that might require carefull timing * with the completion of this command can occur. */ mvi INTSTAT,IMMEDDONE jmp start complete: mov QOUTFIFO,SCBPTR mvi INTSTAT,CMDCMPLT jmp mesgin_done /* * 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. */ mesgin_extended: mvi ARG_1 call inb_next /* extended message length */ mvi A call inb_next /* extended message code */ cmp A,MSG_SDTR je p_mesginSDTR cmp A,MSG_WDTR je p_mesginWDTR jmp rej_mesgin p_mesginWDTR: cmp ARG_1,2 jne rej_mesgin /* extended mesg length=2 */ mvi ARG_1 call inb_next /* Width of bus */ mvi INTSTAT,WDTR_MSG /* let driver know */ test RETURN_1,0xff jz mesgin_done /* Do we need to send WDTR? */ cmp RETURN_1,SEND_REJ je rej_mesgin /* * Bus width was too large * Reject it. */ /* We didn't initiate the wide negotiation, so we must respond to the request */ and RETURN_1,0x7f /* Clear the SEND_WDTR Flag */ mvi DINDEX,MSG0 mvi MSG0 call mk_wdtr /* build WDTR message */ or SINDEX,0x10,SIGSTATE /* turn on ATNO */ call scsisig jmp mesgin_done p_mesginSDTR: cmp ARG_1,3 jne rej_mesgin /* extended mesg length=3 */ mvi ARG_1 call inb_next /* xfer period */ mvi A call inb_next /* REQ/ACK offset */ mvi INTSTAT,SDTR_MSG /* call driver to convert */ test RETURN_1,0xff jz mesgin_done /* Do we need to mk_sdtr/rej */ cmp RETURN_1,SEND_REJ je rej_mesgin /* * Requested SDTR too small * Reject it. */ mvi DINDEX, MSG0 mvi MSG0 call mk_sdtr or SINDEX,0x10,SIGSTATE /* turn on ATNO */ call scsisig jmp mesgin_done /* * Is it a disconnect message? Set a flag in the SCB to remind us * and await the bus going free. */ mesgin_disconnect: or SCB_CONTROL,DISCONNECTED jmp mesgin_done /* * Save data pointers message? Copy working values into the SCB, * usually in preparation for a disconnect. */ mesgin_sdptrs: call sg_ram2scb jmp mesgin_done /* * Restore pointers message? Data pointers are recopied from the * SCB anytime we enter a data phase for the first time, so all * we need to do is clear the DPHASE flag and let the data phase * code do the rest. */ mesgin_rdptrs: and FLAGS,0xfb /* * !DPHASE we'll reload them * the next time through */ jmp mesgin_done /* * Identify message? For a reconnecting target, this tells us the lun * that the reconnection is for - find the correct SCB and switch to it, * clearing the "disconnected" bit so we don't "find" it by accident later. */ mesgin_identify: test A,0x78 jnz rej_mesgin /*!DiscPriv|!LUNTAR|!Reserved*/ and A,0x07 /* lun in lower three bits */ or SAVED_TCL,A,SELID and SAVED_TCL,0xf7 and A,SELBUSB,SBLKCTL /* B Channel?? */ or SAVED_TCL,A call inb_last /* ACK */ /* * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. * If we get one, we use the tag returned to switch to the proper * SCB. Otherwise, we just use the findSCB method. */ snoop_tag_loop: test SSTAT1,BUSFREE jnz use_findSCB test SSTAT1,REQINIT jz snoop_tag_loop test SSTAT1,PHASEMIS jnz use_findSCB mvi A call inb_first cmp A,MSG_SIMPLE_TAG je get_tag use_findSCB: mov ALLZEROS call findSCB /* Have to search */ setup_SCB: and SCB_CONTROL,0xfb /* clear disconnect bit in SCB */ or FLAGS,IDENTIFY_SEEN /* make note of IDENTIFY */ jmp ITloop get_tag: mvi ARG_1 call inb_next /* tag value */ /* * See if the tag is in range. The tag is < SCBCOUNT if we add * the complement of SCBCOUNT to the incomming tag and there is * no carry. */ mov A,COMP_SCBCOUNT add SINDEX,A,ARG_1 jc abort_tag /* * Ensure that the SCB the tag points to is for an SCB transaction * to the reconnecting target. */ mov SCBPTR,ARG_1 mov A,SAVED_TCL cmp SCB_TCL,A jne abort_tag test SCB_CONTROL,TAG_ENB jz abort_tag call inb_last /* Ack Successful tag */ jmp setup_SCB 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 */ jmp mesgin_done /* * Message reject? Let the kernel driver handle this. If we have an * outstanding WDTR or SDTR negotiation, assume that it's a response from * the target selecting 8bit or asynchronous transfer, otherwise just ignore * it since we have no clue what it pertains to. */ mesgin_reject: mvi INTSTAT, REJECT_MSG jmp mesgin_done /* * [ ADD MORE MESSAGE HANDLING HERE ] */ /* * 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,CLRATNO /* * if this is an immediate command, perform a psuedo command complete to * notify the driver. */ test SCB_CMDLEN,0xff jz status_ok jmp start /* * Instead of a generic bcopy routine that requires an argument, we unroll * the cases that are actually used, and call them explicitly. This * not only reduces the overhead of doing a bcopy, 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_7: mov DINDIR,SINDIR mov DINDIR,SINDIR bcopy_5: mov DINDIR,SINDIR bcopy_4: mov DINDIR,SINDIR bcopy_3: mov DINDIR,SINDIR mov DINDIR,SINDIR mov DINDIR,SINDIR ret bcopy_7_dfdat: mov DINDIR,DFDAT mov DINDIR,DFDAT bcopy_5_dfdat: mov DINDIR,DFDAT bcopy_4_dfdat: mov DINDIR,DFDAT bcopy_3_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 MSG_LEN,0xff jz mk_mesg1 /* Should always succeed */ /* * Hmmm. For some reason the mesg buffer is in use. * Tell the driver. It should look at SINDEX to find * out what we wanted to use the buffer for and resolve * the conflict. */ mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ mvi INTSTAT,MSG_BUFFER_BUSY ret mk_mesg1: mvi MSG_LEN,1 /* length = 1 */ mov MSG0,SINDEX /* 1-byte message */ mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ /* * Functions to read data in Automatic PIO mode. * * According to Adaptec's documentation, an ACK is not sent on input from * the target until SCSIDATL is read from. So we wait until SCSIDATL is * latched (the usual way), then read the data byte directly off the bus * using SCSIBUSL. When we have pulled the ATN line, or we just want to * acknowledge the byte, then we do a dummy read from SCISDATL. The SCSI * spec guarantees that the target will hold the data byte on the bus until * we send our ACK. * * The assumption here is that these are called in a particular sequence, * and that REQ is already set when inb_first is called. inb_{first,next} * use the same calling convention as inb. */ inb_next: call inb_last inb_first: test SSTAT1,PHASEMIS jnz mesgin_phasemis test SSTAT0,SPIORDY jz inb_first /* wait for next byte */ mov DINDEX,SINDEX mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ inb_last: or SXFRCTL0,CLRSTCNT mvi STCNT0,0x01 mov NONE,SCSIDATL /*dummy read from latch to ACK*/ inb_last_wait: test SSTAT0,SDONE jz inb_last_wait /* Wait for completion */ ret mesgin_phasemis: /* * We expected to receive another byte, but the target changed phase */ mvi INTSTAT, MSGIN_PHASEMIS jmp ITloop /* * DMA data transfer. HADDR and HCNT must be loaded first, and * SINDEX should contain the value to load DFCNTRL with - 0x3d for * host->scsi, or 0x39 for scsi->host. The SCSI channel is cleared * during initialization. */ dma: mov DFCNTRL,SINDEX dma1: test SSTAT0,DMADONE jnz dma3 test SSTAT1,PHASEMIS jz dma1 /* 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,DIRECTION jnz dma5 dma4: test DFSTATUS,FIFOEMP jz dma4 /* * Now shut the DMA enables off and make sure that the DMA enables are * actually off first lest we get an ILLSADDR. */ dma5: /* disable DMA, but maintain WIDEODD */ and A, WIDEODD, SINDEX mov DFCNTRL, A dma6: test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ ret dma_finish: test DFSTATUS,HDONE jz dma_finish clr DFCNTRL /* disable DMA */ dma_finish2: test DFCNTRL,HDMAENACK jnz dma_finish2 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_scsiid: and SINDEX,0xf0 /* Get target ID */ and A,0x0f,SCSIID or SINDEX,A mov SCSIID,SINDEX 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 */ /* * 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 SCB_TCL,A jne findSCB1 /* target ID/channel/lun match? */ test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ ret findSCB1: inc SINDEX mov A,SCBCOUNT cmp SINDEX,A jne findSCB mvi INTSTAT,NO_MATCH /* not found - signal kernel */ mvi MSG_ABORT call mk_mesg /* ABORT message */ or SINDEX,0x10,SIGSTATE /* assert ATNO */ call scsisig ret /* * Make a working copy of the scatter-gather parameters from the SCB. */ sg_scb2ram: mvi DINDEX,HADDR mvi SCB_DATAPTR call bcopy_7 mvi DINDEX,STCNT mvi SCB_DATACNT call bcopy_3 mov SG_COUNT,SCB_SGCOUNT mvi DINDEX,SG_NEXT mvi SCB_SGPTR call bcopy_4 ret /* * Copying RAM values back to SCB, for Save Data Pointers message, but * only if we've actually been into a data phase to change them. This * protects against bogus data in scratch ram and the residual counts * since they are only initialized when we go into data_in or data_out. */ sg_ram2scb: test FLAGS, DPHASE jz return mov SCB_SGCOUNT,SG_COUNT mvi DINDEX,SCB_SGPTR mvi SG_NEXT call bcopy_4 mvi DINDEX,SCB_DATAPTR mvi SHADDR call bcopy_4 /* * Use the residual number since STCNT is corrupted by any message transfer */ mvi SCB_RESID_DCNT call bcopy_3 ret /* * Add the array base TARG_SCRATCH 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,SELBUSB jz ndx_dtr_2 or A,0x08 /* Channel B entries add 8 */ ndx_dtr_2: add SINDEX,TARG_SCRATCH,A mov FUNCTION1,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 SCB_CONTROL,0x90 jz return /* NEEDWDTR|NEEDSDTR */ test SCB_CONTROL,NEEDWDTR jnz mk_wdtr_16bit or FLAGS, MAXOFFSET /* Force an offset of 15 or 8 if WIDE */ 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, MAXOFFSET jnz mk_sdtr_max_offset and DINDIR,0x0f,SINDIR /* Sync Offset */ mk_sdtr_done: add MSG_LEN,COMP_MSG0,DINDEX ret /* update message length */ mk_sdtr_max_offset: /* * We're initiating sync negotiation, so request the max offset we can (15 or 8) */ xor FLAGS, MAXOFFSET /* Talking to a WIDE device? */ test SCSIRATE, WIDEXFER jnz wmax_offset mvi DINDIR, MAX_OFFSET_8BIT jmp mk_sdtr_done wmax_offset: mvi DINDIR, MAX_OFFSET_16BIT 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,COMP_MSG0,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_1,0x19 dec A jmp sdtr_to_rate_loop sdtr_to_rate_done: shr RETURN_1,0x2 add RETURN_1,0x19 test SXFRCTL0,ULTRAEN jz return shr RETURN_1,0x1 return: ret