/* $NetBSD: aic7xxx.seq,v 1.6 1996/10/08 03:04:06 gibbs Exp $ */ /*+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. * *FreeBSD, Twin, Wide, 2 command per target support, tagged queuing, *SCB paging and other optimizations: *Copyright (c) 1994, 1995, 1996 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. * * from Id: aic7xxx.seq,v 1.42 1996/06/09 17:29:11 gibbs Exp * *-M************************************************************************/ VERSION AIC7XXX_SEQ_VER "$NetBSD: aic7xxx.seq,v 1.6 1996/10/08 03:04:06 gibbs Exp $" #if defined(__NetBSD__) #include "../../ic/aic7xxxreg.h" #include "../../../scsi/scsi_message.h" #elif defined(__FreeBSD__) #include "../../dev/aic7xxx/aic7xxx_reg.h" #include "../../scsi/scsi_message.h" #endif /* * 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 in * the assembler's symbol space. */ A = ACCUM /* After starting the selection hardware, we check for reconnecting targets * as well as for our selection to complete just in case the reselection wins * bus arbitration. The problem with this is that we must keep track of the * SCB that we've already pulled from the QINFIFO and started the selection * on just in case the reselection wins so that we can retry the selection at * a later time. This problem cannot be resolved by holding a single entry * in scratch ram since a reconnecting target can request sense and this will * create yet another SCB waiting for selection. The solution used here is to * use byte 27 of the SCB as a psuedo-next pointer and to thread a list * of SCBs that are awaiting selection. Since 0-0xfe are valid SCB 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. */ /* * We assume that the kernel driver may reset us at any time, even in the * middle of a DMA, so clear DFCNTRL too. */ reset: clr DFCNTRL clr SCSISIGO /* De-assert BSY */ /* * We jump to start after every bus free. */ start: and FLAGS,0x0f /* clear target specific flags */ mvi SCSISEQ,ENRSELI /* Always allow reselection */ clr SCSIRATE /* * We don't know the target we will * connect to, so default to narrow * transfers to avoid parity problems. */ 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 mov A, QCNTMASK test QINCNT,A 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 /* * 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 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_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. */ mk_identify: and A,DISCENB,SCB_CONTROL /* mask off disconnect privledge */ and MSG0,0x7,SCB_TCL /* lun */ or MSG0,A /* or in disconnect privledge */ or MSG0,MSG_IDENTIFYFLAG mvi MSG_LEN, 1 /* * Send a tag message if TAG_ENB is set in the SCB control block. * Use SCB_TAG (the position in the kernel's SCB array) as the tag value. */ mk_tag: test SCB_CONTROL,TAG_ENB jz mk_message mvi DINDEX, MSG1 and DINDIR,0x23,SCB_CONTROL mov DINDIR,SCB_TAG add MSG_LEN,COMP_MSG0,DINDEX /* update message length */ /* * Interrupt the driver, and allow it to tweak the message buffer * if it asks. */ mk_message: test SCB_CONTROL,MK_MESSAGE jz wait_for_selection mvi INTSTAT,AWAITING_MSG 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 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: mov WAITING_SCBH,SCB_NEXT or FLAGS,SELECTED 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. */ or SXFRCTL0,CLRCHN /* * Initialize SCSIRATE with the appropriate value for this target. */ call ndx_dtr mov SCSIRATE,SINDIR /* * Initialize Ultra mode setting. */ mov FUNCTION1,SCSIID mov A,FUNCTION1 and SINDEX,0xdf,SXFRCTL0 /* default to Ultra disabled */ test SCSIID, 0x80 jnz ultra_b /* Target ID > 7 */ test SBLKCTL, SELBUSB jnz ultra_b /* Second channel device */ test ULTRA_ENB,A jz set_sxfrctl0 or SINDEX, ULTRAEN jmp set_sxfrctl0 ultra_b: test ULTRA_ENB_B,A jz set_sxfrctl0 or SINDEX, ULTRAEN set_sxfrctl0: mov SXFRCTL0,SINDEX 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 LASTPHASE,A mov SCSISIGO,A 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 */ jmp ITloop /* Try reading the bus again. */ 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: mov STCNT0,SCB_RESID_DCNT0 mov STCNT1,SCB_RESID_DCNT1 mov STCNT2,SCB_RESID_DCNT2 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: /* Guard against overruns */ test SG_COUNT, 0xff jnz data_phase_inbounds /* * Turn on 'Bit Bucket' mode, set the transfer count to * 16meg and let the target run until it changes phase. * When the transfer completes, notify the host that we * had an overrun. */ or SXFRCTL1,BITBUCKET mvi STCNT0,0xff mvi STCNT1,0xff mvi STCNT2,0xff data_phase_inbounds: /* 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 /* Go tell the host about any overruns */ test SXFRCTL1,BITBUCKET jnz data_phase_overrun /* 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 /* * Load a struct scatter and set up the data address and length. * If the working value of the SG count is nonzero, then * we need to load a new set of values. * * This, like all DMA's, assumes little-endian host data storage. */ sg_load: clr HCNT2 clr HCNT1 mvi HCNT0,SG_SIZEOF mov HADDR0,SG_NEXT0 mov HADDR1,SG_NEXT1 mov HADDR2,SG_NEXT2 mov HADDR3,SG_NEXT3 or 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. */ dma_finish: test DFSTATUS,HDONE jz dma_finish /* Turn off DMA preserving WIDEODD */ and DFCNTRL,WIDEODD dma_finish2: test DFCNTRL,HDMAENACK jnz dma_finish2 /* * 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 for the Linux driver): * * struct scatterlist { * char *address; four bytes, little-endian order * ... four bytes, ignored * unsigned short length; two bytes, little-endian order * } * * * 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 * }; */ mov HADDR0,DFDAT mov HADDR1,DFDAT mov HADDR2,DFDAT mov HADDR3,DFDAT /* * For Linux, we must throw away four bytes since there is a 32bit gap * in the middle of a struct scatterlist. */ #ifdef __linux__ mov NONE,DFDAT mov NONE,DFDAT mov NONE,DFDAT mov NONE,DFDAT #endif mov HCNT0,DFDAT mov HCNT1,DFDAT mov HCNT2,DFDAT /* Load STCNT as well. It is a mirror of HCNT */ mov STCNT0,HCNT0 mov STCNT1,HCNT1 mov STCNT2,HCNT2 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. */ mov SCB_RESID_DCNT0,STCNT0 mov SCB_RESID_DCNT1,STCNT1 mov SCB_RESID_DCNT2,STCNT2 mov SCB_RESID_SGCNT, SG_COUNT jmp ITloop data_phase_overrun: /* * Turn off BITBUCKET mode and notify the host */ and SXFRCTL1,0x7f /* ~BITBUCKET */ mvi INTSTAT,DATA_OVERRUN jmp ITloop /* * Command phase. Set up the DMA registers and let 'er rip. */ p_command: call assert /* * Load HADDR and HCNT. */ mov HADDR0, SCB_CMDPTR0 mov HADDR1, SCB_CMDPTR1 mov HADDR2, SCB_CMDPTR2 mov HADDR3, SCB_CMDPTR3 mov HCNT0, SCB_CMDLEN clr HCNT1 clr HCNT2 mov STCNT0, HCNT0 mov STCNT1, HCNT1 mov STCNT2, HCNT2 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 not an 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_NOOP 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 test SSTAT1,PHASEMIS jnz p_mesgout_phasemis cmp DINDEX,1 jne p_mesgout_outb /* last byte? */ mvi CLRSINT1,CLRATNO /* drop ATN */ p_mesgout_outb: dec DINDEX or CLRSINT0, CLRSPIORDY mov SCSIDATL,SINDIR 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 SCSISIGO,ATNO /* turn on ATNO */ jmp ITloop p_mesgout_phasemis: mvi CLRSINT1,CLRATNO /* Be sure to 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_IDENTIFYFLAG jnz mesgin_identify cmp A,MSG_DISCONNECT je mesgin_disconnect cmp A,MSG_SAVEDATAPOINTER je mesgin_sdptrs cmp ALLZEROS,A je mesgin_complete cmp A,MSG_RESTOREPOINTERS je mesgin_rdptrs cmp A,MSG_EXTENDED je mesgin_extended cmp A,MSG_MESSAGE_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 SCSISIGO,ATNO /* turn on ATNO */ mvi INTSTAT,SEND_REJECT /* let driver know */ mvi MSG_MESSAGE_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_TAG into QUEUEOUT, * 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 SEND_SENSE. If RETURN_1 is set to SEND_SENSE the * sequencer imediately jumps to main loop where it will run down the waiting * SCB list and process the sense request. 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,SCB_TAG mvi INTSTAT,CMDCMPLT jmp mesgin_done /* * Is it an extended message? Copy the message to our message buffer and * notify the host. The host will tell us whether to reject this message, * respond to it with the message that the host placed in our message buffer, * or simply to do nothing. */ mesgin_extended: mvi MSGIN_EXT_LEN call inb_next mvi MSGIN_EXT_OPCODE call inb_next mov A, MSGIN_EXT_LEN dec A /* Length counts the op code */ mvi SINDEX, MSGIN_EXT_BYTE0 mesgin_extended_loop: test A, 0xFF jz mesgin_extended_intr cmp SINDEX, MSGIN_EXT_LASTBYTE je mesgin_extended_dump call inb_next dec A /* * We pass the arg to inb in SINDEX, but DINDEX is the one incremented * so update SINDEX with DINDEX's value before looping again. */ mov DINDEX jmp mesgin_extended_loop mesgin_extended_dump: /* We have no more storage space, so dump the rest */ test A, 0xFF jz mesgin_extended_intr mvi NONE call inb_next dec A jmp mesgin_extended_dump mesgin_extended_intr: mvi INTSTAT,EXTENDED_MSG /* let driver know */ cmp RETURN_1,SEND_REJ je rej_mesgin cmp RETURN_1,SEND_MSG jne mesgin_done /* The kernel has setup a message to be sent */ or SCSISIGO,ATNO /* turn on ATNO */ 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 test FLAGS, PAGESCBS jz mesgin_done /* * Link this SCB into the DISCONNECTED list. This list holds the * candidates for paging out an SCB if one is needed for a new command. * Modifying the disconnected list is a critical(pause dissabled) section. */ mvi SCB_PREV, SCB_LIST_NULL mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ mov SCB_NEXT, DISCONNECTED_SCBH mov DISCONNECTED_SCBH, SCBPTR cmp SCB_NEXT,SCB_LIST_NULL je linkdone mov SCBPTR,SCB_NEXT mov SCB_PREV,DISCONNECTED_SCBH mov SCBPTR,DISCONNECTED_SCBH linkdone: mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ 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,0xef /* * !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 find the proper * SCB. With SCB paging, this requires using findSCB for both tagged * and non-tagged transactions since the SCB may exist in any slot. * If we're not using SCB paging, we can use the tag as the direct * index to the SCB. */ mvi ARG_1,SCB_LIST_NULL /* Default to no-tag */ 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_Q_TAG jne use_findSCB 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. */ test FLAGS, PAGESCBS jz index_by_tag call inb_last /* Ack 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 index_by_tag: 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 SCSISIGO,ATNO /* turn on ATNO */ mvi INTSTAT,ABORT_TAG /* let driver know */ mvi MSG_ABORT_TAG 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 clr LASTPHASE /* * if this is an immediate command, perform a psuedo command complete to * notify the driver. */ test SCB_CMDLEN,0xff jz status_ok jmp start /* * 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 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: or CLRSINT0, CLRSPIORDY mov NONE,SCSIDATL /*dummy read from latch to ACK*/ inb_next_wait: test SSTAT1,PHASEMIS jnz mesgin_phasemis test SSTAT0,SPIORDY jz inb_next_wait /* wait for next byte */ inb_first: mov DINDEX,SINDEX test SSTAT1,PHASEMIS jnz mesgin_phasemis mov DINDIR,SCSIBUSL ret /*read byte directly from bus*/ inb_last: mov NONE,SCSIDATL ret /*dummy read from latch to ACK*/ 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 DFCNTRL,WIDEODD dma6: test DFCNTRL,0x38 jnz dma6 /* SCSIENACK|SDMAENACK|HDMAENACK */ return: 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 the tag * value in ARG_1. If ARG_1 == SCB_LIST_NULL, we're looking for a non-tagged * SCB. Have the kernel print a warning message if it can't be found, and * generate an ABORT/ABORT_TAG message to the target. SINDEX should be * cleared on call. */ findSCB: mov A,SAVED_TCL mov SCBPTR,SINDEX /* switch to next SCB */ mvi SEQCTL,0x50 /* PAUSEDIS|FASTMODE */ cmp SCB_TCL,A jne findSCB1 /* target ID/channel/lun match? */ test SCB_CONTROL,DISCONNECTED jz findSCB1 /*should be disconnected*/ test SCB_CONTROL,TAG_ENB jnz findTaggedSCB cmp ARG_1,SCB_LIST_NULL je foundSCB jmp findSCB1 findTaggedSCB: mov A, ARG_1 /* Tag passed in ARG_1 */ cmp SCB_TAG,A jne findSCB1 /* Found it? */ foundSCB: test FLAGS,PAGESCBS jz foundSCB_ret /* Remove this SCB from the disconnection list */ cmp SCB_NEXT,SCB_LIST_NULL je unlink_prev mov SAVED_LINKPTR, SCB_PREV mov SCBPTR, SCB_NEXT mov SCB_PREV, SAVED_LINKPTR mov SCBPTR, SINDEX unlink_prev: cmp SCB_PREV,SCB_LIST_NULL je rHead/* At the head of the list */ mov SAVED_LINKPTR, SCB_NEXT mov SCBPTR, SCB_PREV mov SCB_NEXT, SAVED_LINKPTR mov SCBPTR, SINDEX mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ rHead: mov DISCONNECTED_SCBH,SCB_NEXT foundSCB_ret: mvi SEQCTL,0x10 ret /* !PAUSEDIS|FASTMODE */ findSCB1: mvi SEQCTL,0x10 /* !PAUSEDIS|FASTMODE */ inc SINDEX mov A,SCBCOUNT cmp SINDEX,A jne findSCB mvi INTSTAT,NO_MATCH /* not found - signal kernel */ cmp RETURN_1,SCB_PAGEDIN je return or SCSISIGO,ATNO /* assert ATNO */ cmp ARG_1,SCB_LIST_NULL jne find_abort_tag mvi MSG_ABORT call mk_mesg jmp ITloop find_abort_tag: mvi MSG_ABORT_TAG call mk_mesg jmp ITloop /* * Make a working copy of the scatter-gather parameters from the SCB. */ sg_scb2ram: mov HADDR0, SCB_DATAPTR0 mov HADDR1, SCB_DATAPTR1 mov HADDR2, SCB_DATAPTR2 mov HADDR3, SCB_DATAPTR3 mov HCNT0, SCB_DATACNT0 mov HCNT1, SCB_DATACNT1 mov HCNT2, SCB_DATACNT2 mov STCNT0, HCNT0 mov STCNT1, HCNT1 mov STCNT2, HCNT2 mov SG_COUNT,SCB_SGCOUNT mov SG_NEXT0, SCB_SGPTR0 mov SG_NEXT1, SCB_SGPTR1 mov SG_NEXT2, SCB_SGPTR2 mov SG_NEXT3, SCB_SGPTR3 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 mov SCB_SGPTR0,SG_NEXT0 mov SCB_SGPTR1,SG_NEXT1 mov SCB_SGPTR2,SG_NEXT2 mov SCB_SGPTR3,SG_NEXT3 mov SCB_DATAPTR0,SHADDR0 mov SCB_DATAPTR1,SHADDR1 mov SCB_DATAPTR2,SHADDR2 mov SCB_DATAPTR3,SHADDR3 /* * Use the residual number since STCNT is corrupted by any message transfer */ mov SCB_DATACNT0,SCB_RESID_DCNT0 mov SCB_DATACNT1,SCB_RESID_DCNT1 mov SCB_DATACNT2,SCB_RESID_DCNT2 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 ret