diff options
Diffstat (limited to 'drivers/scsi/aic7xxx/aic79xx.seq')
| -rw-r--r-- | drivers/scsi/aic7xxx/aic79xx.seq | 2290 |
1 files changed, 2290 insertions, 0 deletions
diff --git a/drivers/scsi/aic7xxx/aic79xx.seq b/drivers/scsi/aic7xxx/aic79xx.seq new file mode 100644 index 0000000000..3a36d9362a --- /dev/null +++ b/drivers/scsi/aic7xxx/aic79xx.seq @@ -0,0 +1,2290 @@ +/* + * Adaptec U320 device driver firmware for Linux and FreeBSD. + * + * Copyright (c) 1994-2001, 2004 Justin T. Gibbs. + * Copyright (c) 2000-2002 Adaptec Inc. + * 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, + * without modification. + * 2. Redistributions in binary form must reproduce at minimum a disclaimer + * substantially similar to the "NO WARRANTY" disclaimer below + * ("Disclaimer") and any redistribution must be conditioned upon + * including a substantially similar Disclaimer requirement for further + * binary redistribution. + * 3. Neither the names of the above-listed copyright holders nor the names + * of any contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * NO WARRANTY + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES. + * + * $FreeBSD$ + */ + +VERSION = "$Id: //depot/aic7xxx/aic7xxx/aic79xx.seq#120 $" +PATCH_ARG_LIST = "struct ahd_softc *ahd" +PREFIX = "ahd_" + +#include "aic79xx.reg" +#include "scsi_message.h" + +restart: +if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) { + test SEQINTCODE, 0xFF jz idle_loop; + SET_SEQINTCODE(NO_SEQINT) +} + +idle_loop: + + if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) { + /* + * Convert ERROR status into a sequencer + * interrupt to handle the case of an + * interrupt collision on the hardware + * setting of HWERR. + */ + test ERROR, 0xFF jz no_error_set; + SET_SEQINTCODE(SAW_HWERR) +no_error_set: + } + SET_MODE(M_SCSI, M_SCSI) + test SCSISEQ0, ENSELO|ENARBO jnz idle_loop_checkbus; + test SEQ_FLAGS2, SELECTOUT_QFROZEN jz check_waiting_list; + /* + * If the kernel has caught up with us, thaw the queue. + */ + mov A, KERNEL_QFREEZE_COUNT; + cmp QFREEZE_COUNT, A jne check_frozen_completions; + mov A, KERNEL_QFREEZE_COUNT[1]; + cmp QFREEZE_COUNT[1], A jne check_frozen_completions; + and SEQ_FLAGS2, ~SELECTOUT_QFROZEN; + jmp check_waiting_list; +check_frozen_completions: + test SSTAT0, SELDO|SELINGO jnz idle_loop_checkbus; +BEGIN_CRITICAL; + /* + * If we have completions stalled waiting for the qfreeze + * to take effect, move them over to the complete_scb list + * now that no selections are pending. + */ + cmp COMPLETE_ON_QFREEZE_HEAD[1],SCB_LIST_NULL je idle_loop_checkbus; + /* + * Find the end of the qfreeze list. The first element has + * to be treated specially. + */ + bmov SCBPTR, COMPLETE_ON_QFREEZE_HEAD, 2; + cmp SCB_NEXT_COMPLETE[1], SCB_LIST_NULL je join_lists; + /* + * Now the normal loop. + */ + bmov SCBPTR, SCB_NEXT_COMPLETE, 2; + cmp SCB_NEXT_COMPLETE[1], SCB_LIST_NULL jne . - 1; +join_lists: + bmov SCB_NEXT_COMPLETE, COMPLETE_SCB_HEAD, 2; + bmov COMPLETE_SCB_HEAD, COMPLETE_ON_QFREEZE_HEAD, 2; + mvi COMPLETE_ON_QFREEZE_HEAD[1], SCB_LIST_NULL; + jmp idle_loop_checkbus; +check_waiting_list: + cmp WAITING_TID_HEAD[1], SCB_LIST_NULL je idle_loop_checkbus; + /* + * ENSELO is cleared by a SELDO, so we must test for SELDO + * one last time. + */ + test SSTAT0, SELDO jnz select_out; + call start_selection; +idle_loop_checkbus: + test SSTAT0, SELDO jnz select_out; +END_CRITICAL; + test SSTAT0, SELDI jnz select_in; + test SCSIPHASE, ~DATA_PHASE_MASK jz idle_loop_check_nonpackreq; + test SCSISIGO, ATNO jz idle_loop_check_nonpackreq; + call unexpected_nonpkt_phase_find_ctxt; +idle_loop_check_nonpackreq: + test SSTAT2, NONPACKREQ jz . + 2; + call unexpected_nonpkt_phase_find_ctxt; + if ((ahd->bugs & AHD_FAINT_LED_BUG) != 0) { + /* + * On Rev A. hardware, the busy LED is only + * turned on automaically during selections + * and re-selections. Make the LED status + * more useful by forcing it to be on so + * long as one of our data FIFOs is active. + */ + and A, FIFO0FREE|FIFO1FREE, DFFSTAT; + cmp A, FIFO0FREE|FIFO1FREE jne . + 3; + and SBLKCTL, ~DIAGLEDEN|DIAGLEDON; + jmp . + 2; + or SBLKCTL, DIAGLEDEN|DIAGLEDON; + } + call idle_loop_gsfifo_in_scsi_mode; + call idle_loop_service_fifos; + call idle_loop_cchan; + jmp idle_loop; + +idle_loop_gsfifo: + SET_MODE(M_SCSI, M_SCSI) +BEGIN_CRITICAL; +idle_loop_gsfifo_in_scsi_mode: + test LQISTAT2, LQIGSAVAIL jz return; + /* + * We have received good status for this transaction. There may + * still be data in our FIFOs draining to the host. Complete + * the SCB only if all data has transferred to the host. + */ +good_status_IU_done: + bmov SCBPTR, GSFIFO, 2; + clr SCB_SCSI_STATUS; + /* + * If a command completed before an attempted task management + * function completed, notify the host after disabling any + * pending select-outs. + */ + test SCB_TASK_MANAGEMENT, 0xFF jz gsfifo_complete_normally; + test SSTAT0, SELDO|SELINGO jnz . + 2; + and SCSISEQ0, ~ENSELO; + SET_SEQINTCODE(TASKMGMT_CMD_CMPLT_OKAY) +gsfifo_complete_normally: + or SCB_CONTROL, STATUS_RCVD; + + /* + * Since this status did not consume a FIFO, we have to + * be a bit more dilligent in how we check for FIFOs pertaining + * to this transaction. There are two states that a FIFO still + * transferring data may be in. + * + * 1) Configured and draining to the host, with a FIFO handler. + * 2) Pending cfg4data, fifo not empty. + * + * Case 1 can be detected by noticing a non-zero FIFO active + * count in the SCB. In this case, we allow the routine servicing + * the FIFO to complete the SCB. + * + * Case 2 implies either a pending or yet to occur save data + * pointers for this same context in the other FIFO. So, if + * we detect case 1, we will properly defer the post of the SCB + * and achieve the desired result. The pending cfg4data will + * notice that status has been received and complete the SCB. + */ + test SCB_FIFO_USE_COUNT, 0xFF jnz idle_loop_gsfifo_in_scsi_mode; + call complete; +END_CRITICAL; + jmp idle_loop_gsfifo_in_scsi_mode; + +idle_loop_service_fifos: + SET_MODE(M_DFF0, M_DFF0) +BEGIN_CRITICAL; + test LONGJMP_ADDR[1], INVALID_ADDR jnz idle_loop_next_fifo; + call longjmp; +END_CRITICAL; +idle_loop_next_fifo: + SET_MODE(M_DFF1, M_DFF1) +BEGIN_CRITICAL; + test LONGJMP_ADDR[1], INVALID_ADDR jz longjmp; +END_CRITICAL; +return: + ret; + +idle_loop_cchan: + SET_MODE(M_CCHAN, M_CCHAN) + test QOFF_CTLSTA, HS_MAILBOX_ACT jz hs_mailbox_empty; + or QOFF_CTLSTA, HS_MAILBOX_ACT; + mov LOCAL_HS_MAILBOX, HS_MAILBOX; +hs_mailbox_empty: +BEGIN_CRITICAL; + test CCSCBCTL, CCARREN|CCSCBEN jz scbdma_idle; + test CCSCBCTL, CCSCBDIR jnz fetch_new_scb_inprog; + test CCSCBCTL, CCSCBDONE jz return; + /* FALLTHROUGH */ +scbdma_tohost_done: + test CCSCBCTL, CCARREN jz fill_qoutfifo_dmadone; + /* + * An SCB has been successfully uploaded to the host. + * If the SCB was uploaded for some reason other than + * bad SCSI status (currently only for underruns), we + * queue the SCB for normal completion. Otherwise, we + * wait until any select-out activity has halted, and + * then queue the completion. + */ + and CCSCBCTL, ~(CCARREN|CCSCBEN); + bmov COMPLETE_DMA_SCB_HEAD, SCB_NEXT_COMPLETE, 2; + cmp SCB_NEXT_COMPLETE[1], SCB_LIST_NULL jne . + 2; + mvi COMPLETE_DMA_SCB_TAIL[1], SCB_LIST_NULL; + test SCB_SCSI_STATUS, 0xff jz scbdma_queue_completion; + bmov SCB_NEXT_COMPLETE, COMPLETE_ON_QFREEZE_HEAD, 2; + bmov COMPLETE_ON_QFREEZE_HEAD, SCBPTR, 2 ret; +scbdma_queue_completion: + bmov SCB_NEXT_COMPLETE, COMPLETE_SCB_HEAD, 2; + bmov COMPLETE_SCB_HEAD, SCBPTR, 2 ret; +fill_qoutfifo_dmadone: + and CCSCBCTL, ~(CCARREN|CCSCBEN); + call qoutfifo_updated; + mvi COMPLETE_SCB_DMAINPROG_HEAD[1], SCB_LIST_NULL; + bmov QOUTFIFO_NEXT_ADDR, SCBHADDR, 4; + test QOFF_CTLSTA, SDSCB_ROLLOVR jz return; + bmov QOUTFIFO_NEXT_ADDR, SHARED_DATA_ADDR, 4; + xor QOUTFIFO_ENTRY_VALID_TAG, QOUTFIFO_ENTRY_VALID_TOGGLE ret; +END_CRITICAL; + +qoutfifo_updated: + /* + * If there are more commands waiting to be dma'ed + * to the host, always coalesce. Otherwise honor the + * host's wishes. + */ + cmp COMPLETE_DMA_SCB_HEAD[1], SCB_LIST_NULL jne coalesce_by_count; + cmp COMPLETE_SCB_HEAD[1], SCB_LIST_NULL jne coalesce_by_count; + test LOCAL_HS_MAILBOX, ENINT_COALESCE jz issue_cmdcmplt; + + /* + * If we have relatively few commands outstanding, don't + * bother waiting for another command to complete. + */ + test CMDS_PENDING[1], 0xFF jnz coalesce_by_count; + /* Add -1 so that jnc means <= not just < */ + add A, -1, INT_COALESCING_MINCMDS; + add NONE, A, CMDS_PENDING; + jnc issue_cmdcmplt; + + /* + * If coalescing, only coalesce up to the limit + * provided by the host driver. + */ +coalesce_by_count: + mov A, INT_COALESCING_MAXCMDS; + add NONE, A, INT_COALESCING_CMDCOUNT; + jc issue_cmdcmplt; + /* + * If the timer is not currently active, + * fire it up. + */ + test INTCTL, SWTMINTMASK jz return; + bmov SWTIMER, INT_COALESCING_TIMER, 2; + mvi CLRSEQINTSTAT, CLRSEQ_SWTMRTO; + or INTCTL, SWTMINTEN|SWTIMER_START; + and INTCTL, ~SWTMINTMASK ret; + +issue_cmdcmplt: + mvi INTSTAT, CMDCMPLT; + clr INT_COALESCING_CMDCOUNT; + or INTCTL, SWTMINTMASK ret; + +BEGIN_CRITICAL; +fetch_new_scb_inprog: + test CCSCBCTL, ARRDONE jz return; +fetch_new_scb_done: + and CCSCBCTL, ~(CCARREN|CCSCBEN); + clr A; + add CMDS_PENDING, 1; + adc CMDS_PENDING[1], A; + if ((ahd->bugs & AHD_PKT_LUN_BUG) != 0) { + /* + * "Short Luns" are not placed into outgoing LQ + * packets in the correct byte order. Use a full + * sized lun field instead and fill it with the + * one byte of lun information we support. + */ + mov SCB_PKT_LUN[6], SCB_LUN; + } + /* + * The FIFO use count field is shared with the + * tag set by the host so that our SCB dma engine + * knows the correct location to store the SCB. + * Set it to zero before processing the SCB. + */ + clr SCB_FIFO_USE_COUNT; + /* Update the next SCB address to download. */ + bmov NEXT_QUEUED_SCB_ADDR, SCB_NEXT_SCB_BUSADDR, 4; + /* + * NULL out the SCB links since these fields + * occupy the same location as SCB_NEXT_SCB_BUSADDR. + */ + mvi SCB_NEXT[1], SCB_LIST_NULL; + mvi SCB_NEXT2[1], SCB_LIST_NULL; + /* Increment our position in the QINFIFO. */ + mov NONE, SNSCB_QOFF; + + /* + * Save SCBID of this SCB in REG0 since + * SCBPTR will be clobbered during target + * list updates. We also record the SCB's + * flags so that we can refer to them even + * after SCBPTR has been changed. + */ + bmov REG0, SCBPTR, 2; + mov A, SCB_CONTROL; + + /* + * Find the tail SCB of the execution queue + * for this target. + */ + shr SINDEX, 3, SCB_SCSIID; + and SINDEX, ~0x1; + mvi SINDEX[1], (WAITING_SCB_TAILS >> 8); + bmov DINDEX, SINDEX, 2; + bmov SCBPTR, SINDIR, 2; + + /* + * Update the tail to point to the new SCB. + */ + bmov DINDIR, REG0, 2; + + /* + * If the queue was empty, queue this SCB as + * the first for this target. + */ + cmp SCBPTR[1], SCB_LIST_NULL je first_new_target_scb; + + /* + * SCBs that want to send messages must always be + * at the head of their per-target queue so that + * ATN can be asserted even if the current + * negotiation agreement is packetized. If the + * target queue is empty, the SCB can be queued + * immediately. If the queue is not empty, we must + * wait for it to empty before entering this SCB + * into the waiting for selection queue. Otherwise + * our batching and round-robin selection scheme + * could allow commands to be queued out of order. + * To simplify the implementation, we stop pulling + * new commands from the host until the MK_MESSAGE + * SCB can be queued to the waiting for selection + * list. + */ + test A, MK_MESSAGE jz batch_scb; + + /* + * If the last SCB is also a MK_MESSAGE SCB, then + * order is preserved even if we batch. + */ + test SCB_CONTROL, MK_MESSAGE jz batch_scb; + + /* + * Defer this SCB and stop fetching new SCBs until + * it can be queued. Since the SCB_SCSIID of the + * tail SCB must be the same as that of the newly + * queued SCB, there is no need to restore the SCBID + * here. + */ + or SEQ_FLAGS2, PENDING_MK_MESSAGE; + bmov MK_MESSAGE_SCB, REG0, 2; + mov MK_MESSAGE_SCSIID, SCB_SCSIID ret; + +batch_scb: + /* + * Otherwise just update the previous tail SCB to + * point to the new tail. + */ + bmov SCB_NEXT, REG0, 2 ret; + +first_new_target_scb: + /* + * Append SCB to the tail of the waiting for + * selection list. + */ + cmp WAITING_TID_HEAD[1], SCB_LIST_NULL je first_new_scb; + bmov SCBPTR, WAITING_TID_TAIL, 2; + bmov SCB_NEXT2, REG0, 2; + bmov WAITING_TID_TAIL, REG0, 2 ret; +first_new_scb: + /* + * Whole list is empty, so the head of + * the list must be initialized too. + */ + bmov WAITING_TID_HEAD, REG0, 2; + bmov WAITING_TID_TAIL, REG0, 2 ret; +END_CRITICAL; + +scbdma_idle: + /* + * Don't bother downloading new SCBs to execute + * if select-outs are currently frozen or we have + * a MK_MESSAGE SCB waiting to enter the queue. + */ + test SEQ_FLAGS2, SELECTOUT_QFROZEN|PENDING_MK_MESSAGE + jnz scbdma_no_new_scbs; +BEGIN_CRITICAL; + test QOFF_CTLSTA, NEW_SCB_AVAIL jnz fetch_new_scb; +scbdma_no_new_scbs: + cmp COMPLETE_DMA_SCB_HEAD[1], SCB_LIST_NULL jne dma_complete_scb; + cmp COMPLETE_SCB_HEAD[1], SCB_LIST_NULL je return; + /* FALLTHROUGH */ +fill_qoutfifo: + /* + * Keep track of the SCBs we are dmaing just + * in case the DMA fails or is aborted. + */ + bmov COMPLETE_SCB_DMAINPROG_HEAD, COMPLETE_SCB_HEAD, 2; + mvi CCSCBCTL, CCSCBRESET; + bmov SCBHADDR, QOUTFIFO_NEXT_ADDR, 4; + mov A, QOUTFIFO_NEXT_ADDR; + bmov SCBPTR, COMPLETE_SCB_HEAD, 2; +fill_qoutfifo_loop: + bmov CCSCBRAM, SCBPTR, 2; + mov CCSCBRAM, SCB_SGPTR[0]; + mov CCSCBRAM, QOUTFIFO_ENTRY_VALID_TAG; + mov NONE, SDSCB_QOFF; + inc INT_COALESCING_CMDCOUNT; + add CMDS_PENDING, -1; + adc CMDS_PENDING[1], -1; + cmp SCB_NEXT_COMPLETE[1], SCB_LIST_NULL je fill_qoutfifo_done; + cmp CCSCBADDR, CCSCBADDR_MAX je fill_qoutfifo_done; + test QOFF_CTLSTA, SDSCB_ROLLOVR jnz fill_qoutfifo_done; + /* + * Don't cross an ADB or Cachline boundary when DMA'ing + * completion entries. In PCI mode, at least in 32/33 + * configurations, the SCB DMA engine may lose its place + * in the data-stream should the target force a retry on + * something other than an 8byte aligned boundary. In + * PCI-X mode, we do this to avoid split transactions since + * many chipsets seem to be unable to format proper split + * completions to continue the data transfer. + */ + add SINDEX, A, CCSCBADDR; + test SINDEX, CACHELINE_MASK jz fill_qoutfifo_done; + bmov SCBPTR, SCB_NEXT_COMPLETE, 2; + jmp fill_qoutfifo_loop; +fill_qoutfifo_done: + mov SCBHCNT, CCSCBADDR; + mvi CCSCBCTL, CCSCBEN|CCSCBRESET; + bmov COMPLETE_SCB_HEAD, SCB_NEXT_COMPLETE, 2; + mvi SCB_NEXT_COMPLETE[1], SCB_LIST_NULL ret; + +fetch_new_scb: + bmov SCBHADDR, NEXT_QUEUED_SCB_ADDR, 4; + mvi CCARREN|CCSCBEN|CCSCBDIR|CCSCBRESET jmp dma_scb; +dma_complete_scb: + bmov SCBPTR, COMPLETE_DMA_SCB_HEAD, 2; + bmov SCBHADDR, SCB_BUSADDR, 4; + mvi CCARREN|CCSCBEN|CCSCBRESET jmp dma_scb; + +/* + * Either post or fetch an SCB from host memory. The caller + * is responsible for polling for transfer completion. + * + * Prerequisits: Mode == M_CCHAN + * SINDEX contains CCSCBCTL flags + * SCBHADDR set to Host SCB address + * SCBPTR set to SCB src location on "push" operations + */ +SET_SRC_MODE M_CCHAN; +SET_DST_MODE M_CCHAN; +dma_scb: + mvi SCBHCNT, SCB_TRANSFER_SIZE; + mov CCSCBCTL, SINDEX ret; + +setjmp: + /* + * At least on the A, a return in the same + * instruction as the bmov results in a return + * to the caller, not to the new address at the + * top of the stack. Since we want the latter + * (we use setjmp to register a handler from an + * interrupt context but not invoke that handler + * until we return to our idle loop), use a + * separate ret instruction. + */ + bmov LONGJMP_ADDR, STACK, 2; + ret; +setjmp_inline: + bmov LONGJMP_ADDR, STACK, 2; +longjmp: + bmov STACK, LONGJMP_ADDR, 2 ret; +END_CRITICAL; + +/*************************** Chip Bug Work Arounds ****************************/ +/* + * Must disable interrupts when setting the mode pointer + * register as an interrupt occurring mid update will + * fail to store the new mode value for restoration on + * an iret. + */ +if ((ahd->bugs & AHD_SET_MODE_BUG) != 0) { +set_mode_work_around: + mvi SEQINTCTL, INTVEC1DSL; + mov MODE_PTR, SINDEX; + clr SEQINTCTL ret; +} + + +if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) { +set_seqint_work_around: + mov SEQINTCODE, SINDEX; + mvi SEQINTCODE, NO_SEQINT ret; +} + +/************************ Packetized LongJmp Routines *************************/ +SET_SRC_MODE M_SCSI; +SET_DST_MODE M_SCSI; +start_selection: +BEGIN_CRITICAL; + if ((ahd->bugs & AHD_SENT_SCB_UPDATE_BUG) != 0) { + /* + * Razor #494 + * Rev A hardware fails to update LAST/CURR/NEXTSCB + * correctly after a packetized selection in several + * situations: + * + * 1) If only one command existed in the queue, the + * LAST/CURR/NEXTSCB are unchanged. + * + * 2) In a non QAS, protocol allowed phase change, + * the queue is shifted 1 too far. LASTSCB is + * the last SCB that was correctly processed. + * + * 3) In the QAS case, if the full list of commands + * was successfully sent, NEXTSCB is NULL and neither + * CURRSCB nor LASTSCB can be trusted. We must + * manually walk the list counting MAXCMDCNT elements + * to find the last SCB that was sent correctly. + * + * To simplify the workaround for this bug in SELDO + * handling, we initialize LASTSCB prior to enabling + * selection so we can rely on it even for case #1 above. + */ + bmov LASTSCB, WAITING_TID_HEAD, 2; + } + bmov CURRSCB, WAITING_TID_HEAD, 2; + bmov SCBPTR, WAITING_TID_HEAD, 2; + shr SELOID, 4, SCB_SCSIID; + /* + * If we want to send a message to the device, ensure + * we are selecting with atn regardless of our packetized + * agreement. Since SPI4 only allows target reset or PPR + * messages if this is a packetized connection, the change + * to our negotiation table entry for this selection will + * be cleared when the message is acted on. + */ + test SCB_CONTROL, MK_MESSAGE jz . + 3; + mov NEGOADDR, SELOID; + or NEGCONOPTS, ENAUTOATNO; + or SCSISEQ0, ENSELO ret; +END_CRITICAL; + +/* + * Allocate a FIFO for a non-packetized transaction. + * In RevA hardware, both FIFOs must be free before we + * can allocate a FIFO for a non-packetized transaction. + */ +allocate_fifo_loop: + /* + * Do whatever work is required to free a FIFO. + */ + call idle_loop_service_fifos; + SET_MODE(M_SCSI, M_SCSI) +allocate_fifo: + if ((ahd->bugs & AHD_NONPACKFIFO_BUG) != 0) { + and A, FIFO0FREE|FIFO1FREE, DFFSTAT; + cmp A, FIFO0FREE|FIFO1FREE jne allocate_fifo_loop; + } else { + test DFFSTAT, FIFO1FREE jnz allocate_fifo1; + test DFFSTAT, FIFO0FREE jz allocate_fifo_loop; + mvi DFFSTAT, B_CURRFIFO_0; + SET_MODE(M_DFF0, M_DFF0) + bmov SCBPTR, ALLOCFIFO_SCBPTR, 2 ret; + } +SET_SRC_MODE M_SCSI; +SET_DST_MODE M_SCSI; +allocate_fifo1: + mvi DFFSTAT, CURRFIFO_1; + SET_MODE(M_DFF1, M_DFF1) + bmov SCBPTR, ALLOCFIFO_SCBPTR, 2 ret; + +/* + * We have been reselected as an initiator + * or selected as a target. + */ +SET_SRC_MODE M_SCSI; +SET_DST_MODE M_SCSI; +select_in: + if ((ahd->bugs & AHD_FAINT_LED_BUG) != 0) { + /* + * On Rev A. hardware, the busy LED is only + * turned on automaically during selections + * and re-selections. Make the LED status + * more useful by forcing it to be on from + * the point of selection until our idle + * loop determines that neither of our FIFOs + * are busy. This handles the non-packetized + * case nicely as we will not return to the + * idle loop until the busfree at the end of + * each transaction. + */ + or SBLKCTL, DIAGLEDEN|DIAGLEDON; + } + if ((ahd->bugs & AHD_BUSFREEREV_BUG) != 0) { + /* + * Test to ensure that the bus has not + * already gone free prior to clearing + * any stale busfree status. This avoids + * a window whereby a busfree just after + * a selection could be missed. + */ + test SCSISIGI, BSYI jz . + 2; + mvi CLRSINT1,CLRBUSFREE; + or SIMODE1, ENBUSFREE; + } + or SXFRCTL0, SPIOEN; + and SAVED_SCSIID, SELID_MASK, SELID; + and A, OID, IOWNID; + or SAVED_SCSIID, A; + mvi CLRSINT0, CLRSELDI; + jmp ITloop; + +/* + * We have successfully selected out. + * + * Clear SELDO. + * Dequeue all SCBs sent from the waiting queue + * Requeue all SCBs *not* sent to the tail of the waiting queue + * Take Razor #494 into account for above. + * + * In Packetized Mode: + * Return to the idle loop. Our interrupt handler will take + * care of any incoming L_Qs. + * + * In Non-Packetize Mode: + * Continue to our normal state machine. + */ +SET_SRC_MODE M_SCSI; +SET_DST_MODE M_SCSI; +select_out: +BEGIN_CRITICAL; + if ((ahd->bugs & AHD_FAINT_LED_BUG) != 0) { + /* + * On Rev A. hardware, the busy LED is only + * turned on automaically during selections + * and re-selections. Make the LED status + * more useful by forcing it to be on from + * the point of re-selection until our idle + * loop determines that neither of our FIFOs + * are busy. This handles the non-packetized + * case nicely as we will not return to the + * idle loop until the busfree at the end of + * each transaction. + */ + or SBLKCTL, DIAGLEDEN|DIAGLEDON; + } + /* Clear out all SCBs that have been successfully sent. */ + if ((ahd->bugs & AHD_SENT_SCB_UPDATE_BUG) != 0) { + /* + * For packetized, the LQO manager clears ENSELO on + * the assertion of SELDO. If we are non-packetized, + * LASTSCB and CURRSCB are accurate. + */ + test SCSISEQ0, ENSELO jnz use_lastscb; + + /* + * The update is correct for LQOSTAT1 errors. All + * but LQOBUSFREE are handled by kernel interrupts. + * If we see LQOBUSFREE, return to the idle loop. + * Once we are out of the select_out critical section, + * the kernel will cleanup the LQOBUSFREE and we will + * eventually restart the selection if appropriate. + */ + test LQOSTAT1, LQOBUSFREE jnz idle_loop; + + /* + * On a phase change oustside of packet boundaries, + * LASTSCB points to the currently active SCB context + * on the bus. + */ + test LQOSTAT2, LQOPHACHGOUTPKT jnz use_lastscb; + + /* + * If the hardware has traversed the whole list, NEXTSCB + * will be NULL, CURRSCB and LASTSCB cannot be trusted, + * but MAXCMDCNT is accurate. If we stop part way through + * the list or only had one command to issue, NEXTSCB[1] is + * not NULL and LASTSCB is the last command to go out. + */ + cmp NEXTSCB[1], SCB_LIST_NULL jne use_lastscb; + + /* + * Brute force walk. + */ + bmov SCBPTR, WAITING_TID_HEAD, 2; + mvi SEQINTCTL, INTVEC1DSL; + mvi MODE_PTR, MK_MODE(M_CFG, M_CFG); + mov A, MAXCMDCNT; + mvi MODE_PTR, MK_MODE(M_SCSI, M_SCSI); + clr SEQINTCTL; +find_lastscb_loop: + dec A; + test A, 0xFF jz found_last_sent_scb; + bmov SCBPTR, SCB_NEXT, 2; + jmp find_lastscb_loop; +use_lastscb: + bmov SCBPTR, LASTSCB, 2; +found_last_sent_scb: + bmov CURRSCB, SCBPTR, 2; +curscb_ww_done: + } else { + bmov SCBPTR, CURRSCB, 2; + } + + /* + * The whole list made it. Clear our tail pointer to indicate + * that the per-target selection queue is now empty. + */ + cmp SCB_NEXT[1], SCB_LIST_NULL je select_out_clear_tail; + + /* + * Requeue any SCBs not sent, to the tail of the waiting Q. + * We know that neither the per-TID list nor the list of + * TIDs is empty. Use this knowledge to our advantage and + * queue the remainder to the tail of the global execution + * queue. + */ + bmov REG0, SCB_NEXT, 2; +select_out_queue_remainder: + bmov SCBPTR, WAITING_TID_TAIL, 2; + bmov SCB_NEXT2, REG0, 2; + bmov WAITING_TID_TAIL, REG0, 2; + jmp select_out_inc_tid_q; + +select_out_clear_tail: + /* + * Queue any pending MK_MESSAGE SCB for this target now + * that the queue is empty. + */ + test SEQ_FLAGS2, PENDING_MK_MESSAGE jz select_out_no_mk_message_scb; + mov A, MK_MESSAGE_SCSIID; + cmp SCB_SCSIID, A jne select_out_no_mk_message_scb; + and SEQ_FLAGS2, ~PENDING_MK_MESSAGE; + bmov REG0, MK_MESSAGE_SCB, 2; + jmp select_out_queue_remainder; + +select_out_no_mk_message_scb: + /* + * Clear this target's execution tail and increment the queue. + */ + shr DINDEX, 3, SCB_SCSIID; + or DINDEX, 1; /* Want only the second byte */ + mvi DINDEX[1], ((WAITING_SCB_TAILS) >> 8); + mvi DINDIR, SCB_LIST_NULL; +select_out_inc_tid_q: + bmov SCBPTR, WAITING_TID_HEAD, 2; + bmov WAITING_TID_HEAD, SCB_NEXT2, 2; + cmp WAITING_TID_HEAD[1], SCB_LIST_NULL jne . + 2; + mvi WAITING_TID_TAIL[1], SCB_LIST_NULL; + bmov SCBPTR, CURRSCB, 2; + mvi CLRSINT0, CLRSELDO; + test LQOSTAT2, LQOPHACHGOUTPKT jnz unexpected_nonpkt_mode_cleared; + test LQOSTAT1, LQOPHACHGINPKT jnz unexpected_nonpkt_mode_cleared; + + /* + * If this is a packetized connection, return to our + * idle_loop and let our interrupt handler deal with + * any connection setup/teardown issues. The only + * exceptions are the case of MK_MESSAGE and task management + * SCBs. + */ + if ((ahd->bugs & AHD_LQO_ATNO_BUG) != 0) { + /* + * In the A, the LQO manager transitions to LQOSTOP0 even if + * we have selected out with ATN asserted and the target + * REQs in a non-packet phase. + */ + test SCB_CONTROL, MK_MESSAGE jz select_out_no_message; + test SCSISIGO, ATNO jnz select_out_non_packetized; +select_out_no_message: + } + test LQOSTAT2, LQOSTOP0 jz select_out_non_packetized; + test SCB_TASK_MANAGEMENT, 0xFF jz idle_loop; + SET_SEQINTCODE(TASKMGMT_FUNC_COMPLETE) + jmp idle_loop; + +select_out_non_packetized: + /* Non packetized request. */ + and SCSISEQ0, ~ENSELO; + if ((ahd->bugs & AHD_BUSFREEREV_BUG) != 0) { + /* + * Test to ensure that the bus has not + * already gone free prior to clearing + * any stale busfree status. This avoids + * a window whereby a busfree just after + * a selection could be missed. + */ + test SCSISIGI, BSYI jz . + 2; + mvi CLRSINT1,CLRBUSFREE; + or SIMODE1, ENBUSFREE; + } + mov SAVED_SCSIID, SCB_SCSIID; + mov SAVED_LUN, SCB_LUN; + mvi SEQ_FLAGS, NO_CDB_SENT; +END_CRITICAL; + or SXFRCTL0, SPIOEN; + + /* + * As soon as we get a successful selection, the target + * should go into the message out phase since we have ATN + * asserted. + */ + mvi MSG_OUT, MSG_IDENTIFYFLAG; + + /* + * Main loop for information transfer phases. Wait for the + * target to assert REQ before checking MSG, C/D and I/O for + * the bus phase. + */ +mesgin_phasemis: +ITloop: + call phase_lock; + + mov A, LASTPHASE; + + test A, ~P_DATAIN_DT jz p_data; + 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; + + SET_SEQINTCODE(BAD_PHASE) + jmp ITloop; /* Try reading the bus again. */ + +/* + * Command phase. Set up the DMA registers and let 'er rip. + */ +p_command: + test SEQ_FLAGS, NOT_IDENTIFIED jz p_command_okay; + SET_SEQINTCODE(PROTO_VIOLATION) +p_command_okay: + test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1)) + jnz p_command_allocate_fifo; + /* + * Command retry. Free our current FIFO and + * re-allocate a FIFO so transfer state is + * reset. + */ +SET_SRC_MODE M_DFF1; +SET_DST_MODE M_DFF1; + mvi DFFSXFRCTL, RSTCHN|CLRSHCNT; + SET_MODE(M_SCSI, M_SCSI) +p_command_allocate_fifo: + bmov ALLOCFIFO_SCBPTR, SCBPTR, 2; + call allocate_fifo; +SET_SRC_MODE M_DFF1; +SET_DST_MODE M_DFF1; + add NONE, -17, SCB_CDB_LEN; + jnc p_command_embedded; +p_command_from_host: + bmov HADDR[0], SCB_HOST_CDB_PTR, 9; + mvi SG_CACHE_PRE, LAST_SEG; + mvi DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN); + jmp p_command_xfer; +p_command_embedded: + bmov SHCNT[0], SCB_CDB_LEN, 1; + bmov DFDAT, SCB_CDB_STORE, 16; + mvi DFCNTRL, SCSIEN; +p_command_xfer: + and SEQ_FLAGS, ~NO_CDB_SENT; + if ((ahd->features & AHD_FAST_CDB_DELIVERY) != 0) { + /* + * To speed up CDB delivery in Rev B, all CDB acks + * are "released" to the output sync as soon as the + * command phase starts. There is only one problem + * with this approach. If the target changes phase + * before all data are sent, we have left over acks + * that can go out on the bus in a data phase. Due + * to other chip contraints, this only happens if + * the target goes to data-in, but if the acks go + * out before we can test SDONE, we'll think that + * the transfer has completed successfully. Work + * around this by taking advantage of the 400ns or + * 800ns dead time between command phase and the REQ + * of the new phase. If the transfer has completed + * successfully, SCSIEN should fall *long* before we + * see a phase change. We thus treat any phasemiss + * that occurs before SCSIEN falls as an incomplete + * transfer. + */ + test SSTAT1, PHASEMIS jnz p_command_xfer_failed; + test DFCNTRL, SCSIEN jnz . - 1; + } else { + test DFCNTRL, SCSIEN jnz .; + } + /* + * DMA Channel automatically disabled. + * Don't allow a data phase if the command + * was not fully transferred. + */ + test SSTAT2, SDONE jnz ITloop; +p_command_xfer_failed: + or SEQ_FLAGS, NO_CDB_SENT; + jmp ITloop; + + +/* + * Status phase. Wait for the data byte to appear, then read it + * and store it into the SCB. + */ +SET_SRC_MODE M_SCSI; +SET_DST_MODE M_SCSI; +p_status: + test SEQ_FLAGS,NOT_IDENTIFIED jnz mesgin_proto_violation; +p_status_okay: + mov SCB_SCSI_STATUS, SCSIDAT; + or SCB_CONTROL, STATUS_RCVD; + jmp ITloop; + +/* + * Message out phase. If MSG_OUT is MSG_IDENTIFYFLAG, build a full + * indentify message sequence and send it to the target. The host may + * override this behavior by setting the MK_MESSAGE bit in the SCB + * control byte. This will cause us to interrupt the host and allow + * it to handle the message phase completely on its own. If the bit + * associated with this target is set, we will also interrupt the host, + * thereby allowing it to send a message on the next selection regardless + * of the transaction being sent. + * + * If MSG_OUT is == HOST_MSG, also interrupt the host and take a message. + * This is done to allow the host to send messages outside of an identify + * sequence while protecting the seqencer from testing the MK_MESSAGE bit + * on an SCB that might not be for the current nexus. (For example, a + * BDR message in response to a bad reselection would leave us pointed to + * an SCB that doesn't have anything to do with the current target). + * + * Otherwise, treat MSG_OUT as a 1 byte message to send (abort, abort tag, + * bus device reset). + * + * When there are no messages to send, MSG_OUT should be set to MSG_NOOP, + * in case the target decides to put us in this phase for some strange + * reason. + */ +p_mesgout_retry: + /* Turn on ATN for the retry */ + mvi SCSISIGO, ATNO; +p_mesgout: + mov SINDEX, MSG_OUT; + cmp SINDEX, MSG_IDENTIFYFLAG jne p_mesgout_from_host; + test SCB_CONTROL,MK_MESSAGE jnz host_message_loop; +p_mesgout_identify: + or SINDEX, MSG_IDENTIFYFLAG|DISCENB, SCB_LUN; + test SCB_CONTROL, DISCENB jnz . + 2; + and SINDEX, ~DISCENB; +/* + * Send a tag message if TAG_ENB is set in the SCB control block. + * Use SCB_NONPACKET_TAG as the tag value. + */ +p_mesgout_tag: + test SCB_CONTROL,TAG_ENB jz p_mesgout_onebyte; + mov SCSIDAT, SINDEX; /* Send the identify message */ + call phase_lock; + cmp LASTPHASE, P_MESGOUT jne p_mesgout_done; + and SCSIDAT,TAG_ENB|SCB_TAG_TYPE,SCB_CONTROL; + call phase_lock; + cmp LASTPHASE, P_MESGOUT jne p_mesgout_done; + mov SCBPTR jmp p_mesgout_onebyte; +/* + * Interrupt the driver, and allow it to handle this message + * phase and any required retries. + */ +p_mesgout_from_host: + cmp SINDEX, HOST_MSG jne p_mesgout_onebyte; + jmp host_message_loop; + +p_mesgout_onebyte: + mvi CLRSINT1, CLRATNO; + mov SCSIDAT, SINDEX; + +/* + * If the next bus phase after ATN drops is message out, it means + * that the target is requesting that the last message(s) be resent. + */ + call phase_lock; + cmp LASTPHASE, P_MESGOUT je p_mesgout_retry; + +p_mesgout_done: + mvi CLRSINT1,CLRATNO; /* Be sure to turn ATNO off */ + mov LAST_MSG, MSG_OUT; + mvi MSG_OUT, MSG_NOOP; /* No message left */ + jmp ITloop; + +/* + * Message in phase. Bytes are read using Automatic PIO mode. + */ +p_mesgin: + /* read the 1st message byte */ + mvi ACCUM call inb_first; + + 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_IGN_WIDE_RESIDUE je mesgin_ign_wide_residue; + cmp A,MSG_NOOP je mesgin_done; + +/* + * Pushed message loop to allow the kernel to + * run it's own message state engine. To avoid an + * extra nop instruction after signaling the kernel, + * we perform the phase_lock before checking to see + * if we should exit the loop and skip the phase_lock + * in the ITloop. Performing back to back phase_locks + * shouldn't hurt, but why do it twice... + */ +host_message_loop: + call phase_lock; /* Benign the first time through. */ + SET_SEQINTCODE(HOST_MSG_LOOP) + cmp RETURN_1, EXIT_MSG_LOOP je ITloop; + cmp RETURN_1, CONT_MSG_LOOP_WRITE jne . + 3; + mov SCSIDAT, RETURN_2; + jmp host_message_loop; + /* Must be CONT_MSG_LOOP_READ */ + mov NONE, SCSIDAT; /* ACK Byte */ + jmp host_message_loop; + +mesgin_ign_wide_residue: + mov SAVED_MODE, MODE_PTR; + SET_MODE(M_SCSI, M_SCSI) + shr NEGOADDR, 4, SAVED_SCSIID; + mov A, NEGCONOPTS; + RESTORE_MODE(SAVED_MODE) + test A, WIDEXFER jz mesgin_reject; + /* Pull the residue byte */ + mvi REG0 call inb_next; + cmp REG0, 0x01 jne mesgin_reject; + test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz . + 2; + test SCB_TASK_ATTRIBUTE, SCB_XFERLEN_ODD jnz mesgin_done; + SET_SEQINTCODE(IGN_WIDE_RES) + jmp mesgin_done; + +mesgin_proto_violation: + SET_SEQINTCODE(PROTO_VIOLATION) + jmp mesgin_done; +mesgin_reject: + mvi MSG_MESSAGE_REJECT call mk_mesg; +mesgin_done: + mov NONE,SCSIDAT; /*dummy read from latch to ACK*/ + jmp ITloop; + +#define INDEX_DISC_LIST(scsiid, lun) \ + and A, 0xC0, scsiid; \ + or SCBPTR, A, lun; \ + clr SCBPTR[1]; \ + and SINDEX, 0x30, scsiid; \ + shr SINDEX, 3; /* Multiply by 2 */ \ + add SINDEX, (SCB_DISCONNECTED_LISTS & 0xFF); \ + mvi SINDEX[1], ((SCB_DISCONNECTED_LISTS >> 8) & 0xFF) + +mesgin_identify: + /* + * Determine whether a target is using tagged or non-tagged + * transactions by first looking at the transaction stored in + * the per-device, disconnected array. If there is no untagged + * transaction for this target, this must be a tagged transaction. + */ + and SAVED_LUN, MSG_IDENTIFY_LUNMASK, A; + INDEX_DISC_LIST(SAVED_SCSIID, SAVED_LUN); + bmov DINDEX, SINDEX, 2; + bmov REG0, SINDIR, 2; + cmp REG0[1], SCB_LIST_NULL je snoop_tag; + /* Untagged. Clear the busy table entry and setup the SCB. */ + bmov DINDIR, ALLONES, 2; + bmov SCBPTR, REG0, 2; + jmp setup_SCB; + +/* + * Here we "snoop" the bus looking for a SIMPLE QUEUE TAG message. + * If we get one, we use the tag returned to find the proper + * SCB. After receiving the tag, look for the SCB at SCB locations tag and + * tag + 256. + */ +snoop_tag: + if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) { + or SEQ_FLAGS, 0x80; + } + mov NONE, SCSIDAT; /* ACK Identify MSG */ + call phase_lock; + if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) { + or SEQ_FLAGS, 0x1; + } + cmp LASTPHASE, P_MESGIN jne not_found_ITloop; + if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) { + or SEQ_FLAGS, 0x2; + } + cmp SCSIBUS, MSG_SIMPLE_Q_TAG jne not_found; +get_tag: + clr SCBPTR[1]; + mvi SCBPTR call inb_next; /* tag value */ +verify_scb: + test SCB_CONTROL,DISCONNECTED jz verify_other_scb; + mov A, SAVED_SCSIID; + cmp SCB_SCSIID, A jne verify_other_scb; + mov A, SAVED_LUN; + cmp SCB_LUN, A je setup_SCB_disconnected; +verify_other_scb: + xor SCBPTR[1], 1; + test SCBPTR[1], 0xFF jnz verify_scb; + jmp not_found; + +/* + * Ensure that the SCB the tag points to is for + * an SCB transaction to the reconnecting target. + */ +setup_SCB: + if ((ahd->flags & AHD_SEQUENCER_DEBUG) != 0) { + or SEQ_FLAGS, 0x10; + } + test SCB_CONTROL,DISCONNECTED jz not_found; +setup_SCB_disconnected: + and SCB_CONTROL,~DISCONNECTED; + clr SEQ_FLAGS; /* make note of IDENTIFY */ + test SCB_SGPTR, SG_LIST_NULL jnz . + 3; + bmov ALLOCFIFO_SCBPTR, SCBPTR, 2; + call allocate_fifo; + /* See if the host wants to send a message upon reconnection */ + test SCB_CONTROL, MK_MESSAGE jz mesgin_done; + mvi HOST_MSG call mk_mesg; + jmp mesgin_done; + +not_found: + SET_SEQINTCODE(NO_MATCH) + jmp mesgin_done; + +not_found_ITloop: + SET_SEQINTCODE(NO_MATCH) + jmp ITloop; + +/* + * We received a "command complete" message. Put the SCB on the complete + * queue and trigger a completion interrupt via the idle loop. Before doing + * so, check to see if there is a residual or the status byte is something + * other than STATUS_GOOD (0). In either of these conditions, we upload the + * SCB back to the host so it can process this information. + */ +mesgin_complete: + + /* + * If ATN is raised, we still want to give the target a message. + * Perhaps there was a parity error on this last message byte. + * Either way, the target should take us to message out phase + * and then attempt to complete the command again. We should use a + * critical section here to guard against a timeout triggering + * for this command and setting ATN while we are still processing + * the completion. + test SCSISIGI, ATNI jnz mesgin_done; + */ + + /* + * If we are identified and have successfully sent the CDB, + * any status will do. Optimize this fast path. + */ + test SCB_CONTROL, STATUS_RCVD jz mesgin_proto_violation; + test SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT jz complete_accepted; + + /* + * If the target never sent an identify message but instead went + * to mesgin to give an invalid message, let the host abort us. + */ + test SEQ_FLAGS, NOT_IDENTIFIED jnz mesgin_proto_violation; + + /* + * If we recevied good status but never successfully sent the + * cdb, abort the command. + */ + test SCB_SCSI_STATUS,0xff jnz complete_accepted; + test SEQ_FLAGS, NO_CDB_SENT jnz mesgin_proto_violation; +complete_accepted: + + /* + * See if we attempted to deliver a message but the target ingnored us. + */ + test SCB_CONTROL, MK_MESSAGE jz complete_nomsg; + SET_SEQINTCODE(MKMSG_FAILED) +complete_nomsg: + call queue_scb_completion; + jmp await_busfree; + +BEGIN_CRITICAL; +freeze_queue: + /* Cancel any pending select-out. */ + test SSTAT0, SELDO|SELINGO jnz . + 2; + and SCSISEQ0, ~ENSELO; + mov ACCUM_SAVE, A; + clr A; + add QFREEZE_COUNT, 1; + adc QFREEZE_COUNT[1], A; + or SEQ_FLAGS2, SELECTOUT_QFROZEN; + mov A, ACCUM_SAVE ret; +END_CRITICAL; + +/* + * Complete the current FIFO's SCB if data for this same + * SCB is not transferring in the other FIFO. + */ +SET_SRC_MODE M_DFF1; +SET_DST_MODE M_DFF1; +pkt_complete_scb_if_fifos_idle: + bmov ARG_1, SCBPTR, 2; + mvi DFFSXFRCTL, CLRCHN; + SET_MODE(M_SCSI, M_SCSI) + bmov SCBPTR, ARG_1, 2; + test SCB_FIFO_USE_COUNT, 0xFF jnz return; +queue_scb_completion: + test SCB_SCSI_STATUS,0xff jnz bad_status; + /* + * Check for residuals + */ + test SCB_SGPTR, SG_LIST_NULL jnz complete; /* No xfer */ + test SCB_SGPTR, SG_FULL_RESID jnz upload_scb;/* Never xfered */ + test SCB_RESIDUAL_SGPTR, SG_LIST_NULL jz upload_scb; +complete: +BEGIN_CRITICAL; + bmov SCB_NEXT_COMPLETE, COMPLETE_SCB_HEAD, 2; + bmov COMPLETE_SCB_HEAD, SCBPTR, 2 ret; +END_CRITICAL; +bad_status: + cmp SCB_SCSI_STATUS, STATUS_PKT_SENSE je upload_scb; + call freeze_queue; +upload_scb: + /* + * Restore SCB TAG since we reuse this field + * in the sequencer. We don't want to corrupt + * it on the host. + */ + bmov SCB_TAG, SCBPTR, 2; +BEGIN_CRITICAL; + or SCB_SGPTR, SG_STATUS_VALID; + mvi SCB_NEXT_COMPLETE[1], SCB_LIST_NULL; + cmp COMPLETE_DMA_SCB_HEAD[1], SCB_LIST_NULL jne add_dma_scb_tail; + bmov COMPLETE_DMA_SCB_HEAD, SCBPTR, 2; + bmov COMPLETE_DMA_SCB_TAIL, SCBPTR, 2 ret; +add_dma_scb_tail: + bmov REG0, SCBPTR, 2; + bmov SCBPTR, COMPLETE_DMA_SCB_TAIL, 2; + bmov SCB_NEXT_COMPLETE, REG0, 2; + bmov COMPLETE_DMA_SCB_TAIL, REG0, 2 ret; +END_CRITICAL; + +/* + * Is it a disconnect message? Set a flag in the SCB to remind us + * and await the bus going free. If this is an untagged transaction + * store the SCB id for it in our untagged target table for lookup on + * a reselection. + */ +mesgin_disconnect: + /* + * If ATN is raised, we still want to give the target a message. + * Perhaps there was a parity error on this last message byte + * or we want to abort this command. Either way, the target + * should take us to message out phase and then attempt to + * disconnect again. + * XXX - Wait for more testing. + test SCSISIGI, ATNI jnz mesgin_done; + */ + test SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT + jnz mesgin_proto_violation; + or SCB_CONTROL,DISCONNECTED; + test SCB_CONTROL, TAG_ENB jnz await_busfree; +queue_disc_scb: + bmov REG0, SCBPTR, 2; + INDEX_DISC_LIST(SAVED_SCSIID, SAVED_LUN); + bmov DINDEX, SINDEX, 2; + bmov DINDIR, REG0, 2; + bmov SCBPTR, REG0, 2; + /* FALLTHROUGH */ +await_busfree: + and SIMODE1, ~ENBUSFREE; + if ((ahd->bugs & AHD_BUSFREEREV_BUG) == 0) { + /* + * In the BUSFREEREV_BUG case, the + * busfree status was cleared at the + * beginning of the connection. + */ + mvi CLRSINT1,CLRBUSFREE; + } + mov NONE, SCSIDAT; /* Ack the last byte */ + test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1)) + jnz await_busfree_not_m_dff; +SET_SRC_MODE M_DFF1; +SET_DST_MODE M_DFF1; +await_busfree_clrchn: + mvi DFFSXFRCTL, CLRCHN; +await_busfree_not_m_dff: + /* clear target specific flags */ + mvi SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT; + test SSTAT1,REQINIT|BUSFREE jz .; + /* + * We only set BUSFREE status once either a new + * phase has been detected or we are really + * BUSFREE. This allows the driver to know + * that we are active on the bus even though + * no identified transaction exists should a + * timeout occur while awaiting busfree. + */ + mvi LASTPHASE, P_BUSFREE; + test SSTAT1, BUSFREE jnz idle_loop; + SET_SEQINTCODE(MISSED_BUSFREE) + + +/* + * Save data pointers message: + * 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. + * Ack the message as soon as possible. + */ +SET_SRC_MODE M_DFF1; +SET_DST_MODE M_DFF1; +mesgin_sdptrs: + mov NONE,SCSIDAT; /*dummy read from latch to ACK*/ + test SEQ_FLAGS, DPHASE jz ITloop; + call save_pointers; + jmp ITloop; + +save_pointers: + /* + * If we are asked to save our position at the end of the + * transfer, just mark us at the end rather than perform a + * full save. + */ + test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz save_pointers_full; + or SCB_SGPTR, SG_LIST_NULL ret; + +save_pointers_full: + /* + * The SCB_DATAPTR becomes the current SHADDR. + * All other information comes directly from our residual + * state. + */ + bmov SCB_DATAPTR, SHADDR, 8; + bmov SCB_DATACNT, SCB_RESIDUAL_DATACNT, 8 ret; + +/* + * 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. We also reset/reallocate the FIFO to make + * sure we have a clean start for the next data or command phase. + */ +mesgin_rdptrs: + and SEQ_FLAGS, ~DPHASE; + test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1)) jnz msgin_rdptrs_get_fifo; + mvi DFFSXFRCTL, RSTCHN|CLRSHCNT; + SET_MODE(M_SCSI, M_SCSI) +msgin_rdptrs_get_fifo: + call allocate_fifo; + jmp mesgin_done; + +phase_lock: + if ((ahd->bugs & AHD_EARLY_REQ_BUG) != 0) { + /* + * Don't ignore persistent REQ assertions just because + * they were asserted within the bus settle delay window. + * This allows us to tolerate devices like the GEM318 + * that violate the SCSI spec. We are careful not to + * count REQ while we are waiting for it to fall during + * an async phase due to our asserted ACK. Each + * sequencer instruction takes ~25ns, so the REQ must + * last at least 100ns in order to be counted as a true + * REQ. + */ + test SCSIPHASE, 0xFF jnz phase_locked; + test SCSISIGI, ACKI jnz phase_lock; + test SCSISIGI, REQI jz phase_lock; + test SCSIPHASE, 0xFF jnz phase_locked; + test SCSISIGI, ACKI jnz phase_lock; + test SCSISIGI, REQI jz phase_lock; +phase_locked: + } else { + test SCSIPHASE, 0xFF jz .; + } + test SSTAT1, SCSIPERR jnz phase_lock; +phase_lock_latch_phase: + and LASTPHASE, PHASE_MASK, SCSISIGI ret; + +/* + * Functions to read data in Automatic PIO mode. + * + * 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: + mov NONE,SCSIDAT; /*dummy read from latch to ACK*/ +inb_next_wait: + /* + * If there is a parity error, wait for the kernel to + * see the interrupt and prepare our message response + * before continuing. + */ + test SCSIPHASE, 0xFF jz .; + test SSTAT1, SCSIPERR jnz inb_next_wait; +inb_next_check_phase: + and LASTPHASE, PHASE_MASK, SCSISIGI; + cmp LASTPHASE, P_MESGIN jne mesgin_phasemis; +inb_first: + clr DINDEX[1]; + mov DINDEX,SINDEX; + mov DINDIR,SCSIBUS ret; /*read byte directly from bus*/ +inb_last: + mov NONE,SCSIDAT ret; /*dummy read from latch to ACK*/ + +mk_mesg: + mvi SCSISIGO, ATNO; + mov MSG_OUT,SINDEX ret; + +SET_SRC_MODE M_DFF1; +SET_DST_MODE M_DFF1; +disable_ccsgen: + test SG_STATE, FETCH_INPROG jz disable_ccsgen_fetch_done; + clr CCSGCTL; +disable_ccsgen_fetch_done: + clr SG_STATE ret; + +service_fifo: + /* + * Do we have any prefetch left??? + */ + test SG_STATE, SEGS_AVAIL jnz idle_sg_avail; + + /* + * Can this FIFO have access to the S/G cache yet? + */ + test CCSGCTL, SG_CACHE_AVAIL jz return; + + /* Did we just finish fetching segs? */ + test CCSGCTL, CCSGDONE jnz idle_sgfetch_complete; + + /* Are we actively fetching segments? */ + test CCSGCTL, CCSGENACK jnz return; + + /* + * Should the other FIFO get the S/G cache first? If + * both FIFOs have been allocated since we last checked + * any FIFO, it is important that we service a FIFO + * that is not actively on the bus first. This guarantees + * that a FIFO will be freed to handle snapshot requests for + * any FIFO that is still on the bus. Chips with RTI do not + * perform snapshots, so don't bother with this test there. + */ + if ((ahd->features & AHD_RTI) == 0) { + /* + * If we're not still receiving SCSI data, + * it is safe to allocate the S/G cache to + * this FIFO. + */ + test DFCNTRL, SCSIEN jz idle_sgfetch_start; + + /* + * Switch to the other FIFO. Non-RTI chips + * also have the "set mode" bug, so we must + * disable interrupts during the switch. + */ + mvi SEQINTCTL, INTVEC1DSL; + xor MODE_PTR, MK_MODE(M_DFF1, M_DFF1); + + /* + * If the other FIFO needs loading, then it + * must not have claimed the S/G cache yet + * (SG_CACHE_AVAIL would have been cleared in + * the original FIFO mode and we test this above). + * Return to the idle loop so we can process the + * FIFO not currently on the bus first. + */ + test SG_STATE, LOADING_NEEDED jz idle_sgfetch_okay; + clr SEQINTCTL ret; +idle_sgfetch_okay: + xor MODE_PTR, MK_MODE(M_DFF1, M_DFF1); + clr SEQINTCTL; + } + +idle_sgfetch_start: + /* + * We fetch a "cacheline aligned" and sized amount of data + * so we don't end up referencing a non-existent page. + * Cacheline aligned is in quotes because the kernel will + * set the prefetch amount to a reasonable level if the + * cacheline size is unknown. + */ + bmov SGHADDR, SCB_RESIDUAL_SGPTR, 4; + mvi SGHCNT, SG_PREFETCH_CNT; + if ((ahd->bugs & AHD_REG_SLOW_SETTLE_BUG) != 0) { + /* + * Need two instructions between "touches" of SGHADDR. + */ + nop; + } + and SGHADDR[0], SG_PREFETCH_ALIGN_MASK, SCB_RESIDUAL_SGPTR; + mvi CCSGCTL, CCSGEN|CCSGRESET; + or SG_STATE, FETCH_INPROG ret; +idle_sgfetch_complete: + /* + * Guard against SG_CACHE_AVAIL activating during sg fetch + * request in the other FIFO. + */ + test SG_STATE, FETCH_INPROG jz return; + clr CCSGCTL; + and CCSGADDR, SG_PREFETCH_ADDR_MASK, SCB_RESIDUAL_SGPTR; + mvi SG_STATE, SEGS_AVAIL|LOADING_NEEDED; +idle_sg_avail: + /* Does the hardware have space for another SG entry? */ + test DFSTATUS, PRELOAD_AVAIL jz return; + /* + * On the A, preloading a segment before HDMAENACK + * comes true can clobber the shadow address of the + * first segment in the S/G FIFO. Wait until it is + * safe to proceed. + */ + if ((ahd->features & AHD_NEW_DFCNTRL_OPTS) == 0) { + test DFCNTRL, HDMAENACK jz return; + } + if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) { + bmov HADDR, CCSGRAM, 8; + } else { + bmov HADDR, CCSGRAM, 4; + } + bmov HCNT, CCSGRAM, 3; + bmov SCB_RESIDUAL_DATACNT[3], CCSGRAM, 1; + if ((ahd->flags & AHD_39BIT_ADDRESSING) != 0) { + and HADDR[4], SG_HIGH_ADDR_BITS, SCB_RESIDUAL_DATACNT[3]; + } + if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) { + /* Skip 4 bytes of pad. */ + add CCSGADDR, 4; + } +sg_advance: + clr A; /* add sizeof(struct scatter) */ + add SCB_RESIDUAL_SGPTR[0],SG_SIZEOF; + adc SCB_RESIDUAL_SGPTR[1],A; + adc SCB_RESIDUAL_SGPTR[2],A; + adc SCB_RESIDUAL_SGPTR[3],A; + mov SINDEX, SCB_RESIDUAL_SGPTR[0]; + test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jz . + 3; + or SINDEX, LAST_SEG; + clr SG_STATE; + mov SG_CACHE_PRE, SINDEX; + if ((ahd->features & AHD_NEW_DFCNTRL_OPTS) != 0) { + /* + * Use SCSIENWRDIS so that SCSIEN is never + * modified by this operation. + */ + or DFCNTRL, PRELOADEN|HDMAEN|SCSIENWRDIS; + } else { + or DFCNTRL, PRELOADEN|HDMAEN; + } + /* + * Do we have another segment in the cache? + */ + add NONE, SG_PREFETCH_CNT_LIMIT, CCSGADDR; + jnc return; + and SG_STATE, ~SEGS_AVAIL ret; + +/* + * Initialize the DMA address and counter from the SCB. + */ +load_first_seg: + bmov HADDR, SCB_DATAPTR, 11; + and REG_ISR, ~SG_FULL_RESID, SCB_SGPTR[0]; + test SCB_DATACNT[3], SG_LAST_SEG jz . + 2; + or REG_ISR, LAST_SEG; + mov SG_CACHE_PRE, REG_ISR; + mvi DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN); + /* + * Since we've are entering a data phase, we will + * rely on the SCB_RESID* fields. Initialize the + * residual and clear the full residual flag. + */ + and SCB_SGPTR[0], ~SG_FULL_RESID; + bmov SCB_RESIDUAL_DATACNT[3], SCB_DATACNT[3], 5; + /* If we need more S/G elements, tell the idle loop */ + test SCB_RESIDUAL_DATACNT[3], SG_LAST_SEG jnz . + 2; + mvi SG_STATE, LOADING_NEEDED ret; + clr SG_STATE ret; + +p_data_handle_xfer: + call setjmp; + test SG_STATE, LOADING_NEEDED jnz service_fifo; +p_data_clear_handler: + or LONGJMP_ADDR[1], INVALID_ADDR ret; + +p_data: + test SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT jz p_data_allowed; + SET_SEQINTCODE(PROTO_VIOLATION) +p_data_allowed: + + test SEQ_FLAGS, DPHASE jz data_phase_initialize; + + /* + * If we re-enter the data phase after going through another + * phase, our transfer location has almost certainly been + * corrupted by the interveining, non-data, transfers. Ask + * the host driver to fix us up based on the transfer residual + * unless we already know that we should be bitbucketing. + */ + test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jnz p_data_bitbucket; + SET_SEQINTCODE(PDATA_REINIT) + jmp data_phase_inbounds; + +p_data_bitbucket: + /* + * Turn on `Bit Bucket' mode, wait until the target takes + * us to another phase, and then notify the host. + */ + mov SAVED_MODE, MODE_PTR; + test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1)) + jnz bitbucket_not_m_dff; + /* + * Ensure that any FIFO contents are cleared out and the + * FIFO free'd prior to starting the BITBUCKET. BITBUCKET + * doesn't discard data already in the FIFO. + */ + mvi DFFSXFRCTL, RSTCHN|CLRSHCNT; + SET_MODE(M_SCSI, M_SCSI) +bitbucket_not_m_dff: + or SXFRCTL1,BITBUCKET; + /* Wait for non-data phase. */ + test SCSIPHASE, ~DATA_PHASE_MASK jz .; + and SXFRCTL1, ~BITBUCKET; + RESTORE_MODE(SAVED_MODE) +SET_SRC_MODE M_DFF1; +SET_DST_MODE M_DFF1; + SET_SEQINTCODE(DATA_OVERRUN) + jmp ITloop; + +data_phase_initialize: + test SCB_SGPTR[0], SG_LIST_NULL jnz p_data_bitbucket; + call load_first_seg; +data_phase_inbounds: + /* We have seen a data phase at least once. */ + or SEQ_FLAGS, DPHASE; + mov SAVED_MODE, MODE_PTR; + test SG_STATE, LOADING_NEEDED jz data_group_dma_loop; + call p_data_handle_xfer; +data_group_dma_loop: + /* + * The transfer is complete if either the last segment + * completes or the target changes phase. Both conditions + * will clear SCSIEN. + */ + call idle_loop_service_fifos; + call idle_loop_cchan; + call idle_loop_gsfifo; + RESTORE_MODE(SAVED_MODE) + test DFCNTRL, SCSIEN jnz data_group_dma_loop; + +data_group_dmafinish: + /* + * The transfer has terminated either due to a phase + * change, and/or the completion of the last segment. + * We have two goals here. Do as much other work + * as possible while the data fifo drains on a read + * and respond as quickly as possible to the standard + * messages (save data pointers/disconnect and command + * complete) that usually follow a data phase. + */ + call calc_residual; + + /* + * Go ahead and shut down the DMA engine now. + */ + test DFCNTRL, DIRECTION jnz data_phase_finish; +data_group_fifoflush: + if ((ahd->bugs & AHD_AUTOFLUSH_BUG) != 0) { + or DFCNTRL, FIFOFLUSH; + } + /* + * We have enabled the auto-ack feature. This means + * that the controller may have already transferred + * some overrun bytes into the data FIFO and acked them + * on the bus. The only way to detect this situation is + * to wait for LAST_SEG_DONE to come true on a completed + * transfer and then test to see if the data FIFO is + * non-empty. We know there is more data yet to transfer + * if SG_LIST_NULL is not yet set, thus there cannot be + * an overrun. + */ + test SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL jz data_phase_finish; + test SG_CACHE_SHADOW, LAST_SEG_DONE jz .; + test DFSTATUS, FIFOEMP jnz data_phase_finish; + /* Overrun */ + jmp p_data; +data_phase_finish: + /* + * If the target has left us in data phase, loop through + * the dma code again. We will only loop if there is a + * data overrun. + */ + if ((ahd->flags & AHD_TARGETROLE) != 0) { + test SSTAT0, TARGET jnz data_phase_done; + } + if ((ahd->flags & AHD_INITIATORROLE) != 0) { + test SSTAT1, REQINIT jz .; + test SCSIPHASE, DATA_PHASE_MASK jnz p_data; + } + +data_phase_done: + /* Kill off any pending prefetch */ + call disable_ccsgen; + or LONGJMP_ADDR[1], INVALID_ADDR; + + if ((ahd->flags & AHD_TARGETROLE) != 0) { + test SEQ_FLAGS, DPHASE_PENDING jz ITloop; + /* + and SEQ_FLAGS, ~DPHASE_PENDING; + * For data-in phases, wait for any pending acks from the + * initiator before changing phase. We only need to + * send Ignore Wide Residue messages for data-in phases. + test DFCNTRL, DIRECTION jz target_ITloop; + test SSTAT1, REQINIT jnz .; + test SCB_TASK_ATTRIBUTE, SCB_XFERLEN_ODD jz target_ITloop; + SET_MODE(M_SCSI, M_SCSI) + test NEGCONOPTS, WIDEXFER jz target_ITloop; + */ + /* + * Issue an Ignore Wide Residue Message. + mvi P_MESGIN|BSYO call change_phase; + mvi MSG_IGN_WIDE_RESIDUE call target_outb; + mvi 1 call target_outb; + jmp target_ITloop; + */ + } else { + jmp ITloop; + } + +/* + * We assume that, even though data may still be + * transferring to the host, that the SCSI side of + * the DMA engine is now in a static state. This + * allows us to update our notion of where we are + * in this transfer. + * + * If, by chance, we stopped before being able + * to fetch additional segments for this transfer, + * yet the last S/G was completely exhausted, + * call our idle loop until it is able to load + * another segment. This will allow us to immediately + * pickup on the next segment on the next data phase. + * + * If we happened to stop on the last segment, then + * our residual information is still correct from + * the idle loop and there is no need to perform + * any fixups. + */ +residual_before_last_seg: + test MDFFSTAT, SHVALID jnz sgptr_fixup; + /* + * Can never happen from an interrupt as the packetized + * hardware will only interrupt us once SHVALID or + * LAST_SEG_DONE. + */ + call idle_loop_service_fifos; + RESTORE_MODE(SAVED_MODE) + /* FALLTHROUGH */ +calc_residual: + test SG_CACHE_SHADOW, LAST_SEG jz residual_before_last_seg; + /* Record if we've consumed all S/G entries */ + test MDFFSTAT, SHVALID jz . + 2; + bmov SCB_RESIDUAL_DATACNT, SHCNT, 3 ret; + or SCB_RESIDUAL_SGPTR[0], SG_LIST_NULL ret; + +sgptr_fixup: + /* + * Fixup the residual next S/G pointer. The S/G preload + * feature of the chip allows us to load two elements + * in addition to the currently active element. We + * store the bottom byte of the next S/G pointer in + * the SG_CACHE_PTR register so we can restore the + * correct value when the DMA completes. If the next + * sg ptr value has advanced to the point where higher + * bytes in the address have been affected, fix them + * too. + */ + test SG_CACHE_SHADOW, 0x80 jz sgptr_fixup_done; + test SCB_RESIDUAL_SGPTR[0], 0x80 jnz sgptr_fixup_done; + add SCB_RESIDUAL_SGPTR[1], -1; + adc SCB_RESIDUAL_SGPTR[2], -1; + adc SCB_RESIDUAL_SGPTR[3], -1; +sgptr_fixup_done: + and SCB_RESIDUAL_SGPTR[0], SG_ADDR_MASK, SG_CACHE_SHADOW; + clr SCB_RESIDUAL_DATACNT[3]; /* We are not the last seg */ + bmov SCB_RESIDUAL_DATACNT, SHCNT, 3 ret; + +export timer_isr: + call issue_cmdcmplt; + mvi CLRSEQINTSTAT, CLRSEQ_SWTMRTO; + if ((ahd->bugs & AHD_SET_MODE_BUG) != 0) { + /* + * In H2A4, the mode pointer is not saved + * for intvec2, but is restored on iret. + * This can lead to the restoration of a + * bogus mode ptr. Manually clear the + * intmask bits and do a normal return + * to compensate. + */ + and SEQINTCTL, ~(INTMASK2|INTMASK1) ret; + } else { + or SEQINTCTL, IRET ret; + } + +export seq_isr: + if ((ahd->features & AHD_RTI) == 0) { + /* + * On RevA Silicon, if the target returns us to data-out + * after we have already trained for data-out, it is + * possible for us to transition the free running clock to + * data-valid before the required 100ns P1 setup time (8 P1 + * assertions in fast-160 mode). This will only happen if + * this L-Q is a continuation of a data transfer for which + * we have already prefetched data into our FIFO (LQ/Data + * followed by LQ/Data for the same write transaction). + * This can cause some target implementations to miss the + * first few data transfers on the bus. We detect this + * situation by noticing that this is the first data transfer + * after an LQ (LQIWORKONLQ true), that the data transfer is + * a continuation of a transfer already setup in our FIFO + * (SAVEPTRS interrupt), and that the transaction is a write + * (DIRECTION set in DFCNTRL). The delay is performed by + * disabling SCSIEN until we see the first REQ from the + * target. + * + * First instruction in an ISR cannot be a branch on + * Rev A. Snapshot LQISTAT2 so the status is not missed + * and deffer the test by one instruction. + */ + mov REG_ISR, LQISTAT2; + test REG_ISR, LQIWORKONLQ jz main_isr; + test SEQINTSRC, SAVEPTRS jz main_isr; + test LONGJMP_ADDR[1], INVALID_ADDR jz saveptr_active_fifo; + /* + * Switch to the active FIFO after clearing the snapshot + * savepointer in the current FIFO. We do this so that + * a pending CTXTDONE or SAVEPTR is visible in the active + * FIFO. This status is the only way we can detect if we + * have lost the race (e.g. host paused us) and our attempts + * to disable the channel occurred after all REQs were + * already seen and acked (REQINIT never comes true). + */ + mvi DFFSXFRCTL, CLRCHN; + xor MODE_PTR, MK_MODE(M_DFF1, M_DFF1); + test DFCNTRL, DIRECTION jz interrupt_return; + and DFCNTRL, ~SCSIEN; +snapshot_wait_data_valid: + test SEQINTSRC, (CTXTDONE|SAVEPTRS) jnz interrupt_return; + test SSTAT1, REQINIT jz snapshot_wait_data_valid; +snapshot_data_valid: + or DFCNTRL, SCSIEN; + or SEQINTCTL, IRET ret; +snapshot_saveptr: + mvi DFFSXFRCTL, CLRCHN; + or SEQINTCTL, IRET ret; +main_isr: + } + test SEQINTSRC, CFG4DATA jnz cfg4data_intr; + test SEQINTSRC, CFG4ISTAT jnz cfg4istat_intr; + test SEQINTSRC, SAVEPTRS jnz saveptr_intr; + test SEQINTSRC, CFG4ICMD jnz cfg4icmd_intr; + SET_SEQINTCODE(INVALID_SEQINT) + +/* + * There are two types of save pointers interrupts: + * The first is a snapshot save pointers where the current FIFO is not + * active and contains a snapshot of the current poniter information. + * This happens between packets in a stream for a single L_Q. Since we + * are not performing a pointer save, we can safely clear the channel + * so it can be used for other transactions. On RTI capable controllers, + * where snapshots can, and are, disabled, the code to handle this type + * of snapshot is not active. + * + * The second case is a save pointers on an active FIFO which occurs + * if the target changes to a new L_Q or busfrees/QASes and the transfer + * has a residual. This should occur coincident with a ctxtdone. We + * disable the interrupt and allow our active routine to handle the + * save. + */ +saveptr_intr: + if ((ahd->features & AHD_RTI) == 0) { + test LONGJMP_ADDR[1], INVALID_ADDR jnz snapshot_saveptr; + } +saveptr_active_fifo: + and SEQIMODE, ~ENSAVEPTRS; + or SEQINTCTL, IRET ret; + +cfg4data_intr: + test SCB_SGPTR[0], SG_LIST_NULL jnz pkt_handle_overrun_inc_use_count; + call load_first_seg; + call pkt_handle_xfer; + inc SCB_FIFO_USE_COUNT; +interrupt_return: + or SEQINTCTL, IRET ret; + +cfg4istat_intr: + call freeze_queue; + add NONE, -13, SCB_CDB_LEN; + jnc cfg4istat_have_sense_addr; + test SCB_CDB_LEN, SCB_CDB_LEN_PTR jnz cfg4istat_have_sense_addr; + /* + * Host sets up address/count and enables transfer. + */ + SET_SEQINTCODE(CFG4ISTAT_INTR) + jmp cfg4istat_setup_handler; +cfg4istat_have_sense_addr: + bmov HADDR, SCB_SENSE_BUSADDR, 4; + mvi HCNT[1], (AHD_SENSE_BUFSIZE >> 8); + mvi SG_CACHE_PRE, LAST_SEG; + mvi DFCNTRL, PRELOADEN|SCSIEN|HDMAEN; +cfg4istat_setup_handler: + /* + * Status pkt is transferring to host. + * Wait in idle loop for transfer to complete. + * If a command completed before an attempted + * task management function completed, notify the host. + */ + test SCB_TASK_MANAGEMENT, 0xFF jz cfg4istat_no_taskmgmt_func; + SET_SEQINTCODE(TASKMGMT_CMD_CMPLT_OKAY) +cfg4istat_no_taskmgmt_func: + call pkt_handle_status; + or SEQINTCTL, IRET ret; + +cfg4icmd_intr: + /* + * In the case of DMAing a CDB from the host, the normal + * CDB buffer is formatted with an 8 byte address followed + * by a 1 byte count. + */ + bmov HADDR[0], SCB_HOST_CDB_PTR, 9; + mvi SG_CACHE_PRE, LAST_SEG; + mvi DFCNTRL, (PRELOADEN|SCSIEN|HDMAEN); + call pkt_handle_cdb; + or SEQINTCTL, IRET ret; + +/* + * See if the target has gone on in this context creating an + * overrun condition. For the write case, the hardware cannot + * ack bytes until data are provided. So, if the target begins + * another packet without changing contexts, implying we are + * not sitting on a packet boundary, we are in an overrun + * situation. For the read case, the hardware will continue to + * ack bytes into the FIFO, and may even ack the last overrun packet + * into the FIFO. If the FIFO should become non-empty, we are in + * a read overrun case. + */ +#define check_overrun \ + /* Not on a packet boundary. */ \ + test MDFFSTAT, DLZERO jz pkt_handle_overrun; \ + test DFSTATUS, FIFOEMP jz pkt_handle_overrun + +pkt_handle_xfer: + test SG_STATE, LOADING_NEEDED jz pkt_last_seg; + call setjmp; + test SEQINTSRC, SAVEPTRS jnz pkt_saveptrs; + test SCSIPHASE, ~DATA_PHASE_MASK jz . + 2; + test SCSISIGO, ATNO jnz . + 2; + test SSTAT2, NONPACKREQ jz pkt_service_fifo; + /* + * Defer handling of this NONPACKREQ until we + * can be sure it pertains to this FIFO. SAVEPTRS + * will not be asserted if the NONPACKREQ is for us, + * so we must simulate it if shadow is valid. If + * shadow is not valid, keep running this FIFO until we + * have satisfied the transfer by loading segments and + * waiting for either shadow valid or last_seg_done. + */ + test MDFFSTAT, SHVALID jnz pkt_saveptrs; +pkt_service_fifo: + test SG_STATE, LOADING_NEEDED jnz service_fifo; +pkt_last_seg: + call setjmp; + test SEQINTSRC, SAVEPTRS jnz pkt_saveptrs; + test SG_CACHE_SHADOW, LAST_SEG_DONE jnz pkt_last_seg_done; + test SCSIPHASE, ~DATA_PHASE_MASK jz . + 2; + test SCSISIGO, ATNO jnz . + 2; + test SSTAT2, NONPACKREQ jz return; + test MDFFSTAT, SHVALID jz return; + /* FALLTHROUGH */ + +/* + * Either a SAVEPTRS interrupt condition is pending for this FIFO + * or we have a pending NONPACKREQ for this FIFO. We differentiate + * between the two by capturing the state of the SAVEPTRS interrupt + * prior to clearing this status and executing the common code for + * these two cases. + */ +pkt_saveptrs: +BEGIN_CRITICAL; + if ((ahd->bugs & AHD_AUTOFLUSH_BUG) != 0) { + or DFCNTRL, FIFOFLUSH; + } + mov REG0, SEQINTSRC; + call calc_residual; + call save_pointers; + mvi CLRSEQINTSRC, CLRSAVEPTRS; + call disable_ccsgen; + or SEQIMODE, ENSAVEPTRS; + test DFCNTRL, DIRECTION jnz pkt_saveptrs_check_status; + test DFSTATUS, FIFOEMP jnz pkt_saveptrs_check_status; + /* + * Keep a handler around for this FIFO until it drains + * to the host to guarantee that we don't complete the + * command to the host before the data arrives. + */ +pkt_saveptrs_wait_fifoemp: + call setjmp; + test DFSTATUS, FIFOEMP jz return; +pkt_saveptrs_check_status: + or LONGJMP_ADDR[1], INVALID_ADDR; + test REG0, SAVEPTRS jz unexpected_nonpkt_phase; + dec SCB_FIFO_USE_COUNT; + test SCB_CONTROL, STATUS_RCVD jnz pkt_complete_scb_if_fifos_idle; + mvi DFFSXFRCTL, CLRCHN ret; + +/* + * LAST_SEG_DONE status has been seen in the current FIFO. + * This indicates that all of the allowed data for this + * command has transferred across the SCSI and host buses. + * Check for overrun and see if we can complete this command. + */ +pkt_last_seg_done: + /* + * Mark transfer as completed. + */ + or SCB_SGPTR, SG_LIST_NULL; + + /* + * Wait for the current context to finish to verify that + * no overrun condition has occurred. + */ + test SEQINTSRC, CTXTDONE jnz pkt_ctxt_done; + call setjmp; +pkt_wait_ctxt_done_loop: + test SEQINTSRC, CTXTDONE jnz pkt_ctxt_done; + /* + * A sufficiently large overrun or a NONPACKREQ may + * prevent CTXTDONE from ever asserting, so we must + * poll for these statuses too. + */ + check_overrun; + test SSTAT2, NONPACKREQ jz return; + test SEQINTSRC, CTXTDONE jz unexpected_nonpkt_phase; + /* FALLTHROUGH */ + +pkt_ctxt_done: + check_overrun; + or LONGJMP_ADDR[1], INVALID_ADDR; + /* + * If status has been received, it is safe to skip + * the check to see if another FIFO is active because + * LAST_SEG_DONE has been observed. However, we check + * the FIFO anyway since it costs us only one extra + * instruction to leverage common code to perform the + * SCB completion. + */ + dec SCB_FIFO_USE_COUNT; + test SCB_CONTROL, STATUS_RCVD jnz pkt_complete_scb_if_fifos_idle; + mvi DFFSXFRCTL, CLRCHN ret; +END_CRITICAL; + +/* + * Must wait until CDB xfer is over before issuing the + * clear channel. + */ +pkt_handle_cdb: + call setjmp; + test SG_CACHE_SHADOW, LAST_SEG_DONE jz return; + or LONGJMP_ADDR[1], INVALID_ADDR; + mvi DFFSXFRCTL, CLRCHN ret; + +/* + * Watch over the status transfer. Our host sense buffer is + * large enough to take the maximum allowed status packet. + * None-the-less, we must still catch and report overruns to + * the host. Additionally, properly catch unexpected non-packet + * phases that are typically caused by CRC errors in status packet + * transmission. + */ +pkt_handle_status: + call setjmp; + test SG_CACHE_SHADOW, LAST_SEG_DONE jnz pkt_status_check_overrun; + test SEQINTSRC, CTXTDONE jz pkt_status_check_nonpackreq; + test SG_CACHE_SHADOW, LAST_SEG_DONE jnz pkt_status_check_overrun; +pkt_status_IU_done: + if ((ahd->bugs & AHD_AUTOFLUSH_BUG) != 0) { + or DFCNTRL, FIFOFLUSH; + } + test DFSTATUS, FIFOEMP jz return; +BEGIN_CRITICAL; + or LONGJMP_ADDR[1], INVALID_ADDR; + mvi SCB_SCSI_STATUS, STATUS_PKT_SENSE; + or SCB_CONTROL, STATUS_RCVD; + jmp pkt_complete_scb_if_fifos_idle; +END_CRITICAL; +pkt_status_check_overrun: + /* + * Status PKT overruns are uncerimoniously recovered with a + * bus reset. If we've overrun, let the host know so that + * recovery can be performed. + * + * LAST_SEG_DONE has been observed. If either CTXTDONE or + * a NONPACKREQ phase change have occurred and the FIFO is + * empty, there is no overrun. + */ + test DFSTATUS, FIFOEMP jz pkt_status_report_overrun; + test SEQINTSRC, CTXTDONE jz . + 2; + test DFSTATUS, FIFOEMP jnz pkt_status_IU_done; + test SCSIPHASE, ~DATA_PHASE_MASK jz return; + test DFSTATUS, FIFOEMP jnz pkt_status_check_nonpackreq; +pkt_status_report_overrun: + SET_SEQINTCODE(STATUS_OVERRUN) + /* SEQUENCER RESTARTED */ +pkt_status_check_nonpackreq: + /* + * CTXTDONE may be held off if a NONPACKREQ is associated with + * the current context. If a NONPACKREQ is observed, decide + * if it is for the current context. If it is for the current + * context, we must defer NONPACKREQ processing until all data + * has transferred to the host. + */ + test SCSIPHASE, ~DATA_PHASE_MASK jz return; + test SCSISIGO, ATNO jnz . + 2; + test SSTAT2, NONPACKREQ jz return; + test SEQINTSRC, CTXTDONE jnz pkt_status_IU_done; + test DFSTATUS, FIFOEMP jz return; + /* + * The unexpected nonpkt phase handler assumes that any + * data channel use will have a FIFO reference count. It + * turns out that the status handler doesn't need a references + * count since the status received flag, and thus completion + * processing, cannot be set until the handler is finished. + * We increment the count here to make the nonpkt handler + * happy. + */ + inc SCB_FIFO_USE_COUNT; + /* FALLTHROUGH */ + +/* + * Nonpackreq is a polled status. It can come true in three situations: + * we have received an L_Q, we have sent one or more L_Qs, or there is no + * L_Q context associated with this REQ (REQ occurs immediately after a + * (re)selection). Routines that know that the context responsible for this + * nonpackreq call directly into unexpected_nonpkt_phase. In the case of the + * top level idle loop, we exhaust all active contexts prior to determining that + * we simply do not have the full I_T_L_Q for this phase. + */ +unexpected_nonpkt_phase_find_ctxt: + /* + * This nonpackreq is most likely associated with one of the tags + * in a FIFO or an outgoing LQ. Only treat it as an I_T only + * nonpackreq if we've cleared out the FIFOs and handled any + * pending SELDO. + */ +SET_SRC_MODE M_SCSI; +SET_DST_MODE M_SCSI; + and A, FIFO1FREE|FIFO0FREE, DFFSTAT; + cmp A, FIFO1FREE|FIFO0FREE jne return; + test SSTAT0, SELDO jnz return; + mvi SCBPTR[1], SCB_LIST_NULL; +unexpected_nonpkt_phase: + test MODE_PTR, ~(MK_MODE(M_DFF1, M_DFF1)) + jnz unexpected_nonpkt_mode_cleared; +SET_SRC_MODE M_DFF0; +SET_DST_MODE M_DFF0; + or LONGJMP_ADDR[1], INVALID_ADDR; + dec SCB_FIFO_USE_COUNT; + mvi DFFSXFRCTL, CLRCHN; +unexpected_nonpkt_mode_cleared: + mvi CLRSINT2, CLRNONPACKREQ; + if ((ahd->bugs & AHD_BUSFREEREV_BUG) != 0) { + /* + * Test to ensure that the bus has not + * already gone free prior to clearing + * any stale busfree status. This avoids + * a window whereby a busfree just after + * a selection could be missed. + */ + test SCSISIGI, BSYI jz . + 2; + mvi CLRSINT1,CLRBUSFREE; + or SIMODE1, ENBUSFREE; + } + test SCSIPHASE, ~(MSG_IN_PHASE|MSG_OUT_PHASE) jnz illegal_phase; + SET_SEQINTCODE(ENTERING_NONPACK) + jmp ITloop; + +illegal_phase: + SET_SEQINTCODE(ILLEGAL_PHASE) + jmp ITloop; + +/* + * We have entered an overrun situation. If we have working + * BITBUCKET, flip that on and let the hardware eat any overrun + * data. Otherwise use an overrun buffer in the host to simulate + * BITBUCKET. + */ +pkt_handle_overrun_inc_use_count: + inc SCB_FIFO_USE_COUNT; +pkt_handle_overrun: + SET_SEQINTCODE(CFG4OVERRUN) + call freeze_queue; + if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) == 0) { + or DFFSXFRCTL, DFFBITBUCKET; +SET_SRC_MODE M_DFF1; +SET_DST_MODE M_DFF1; + } else { + call load_overrun_buf; + mvi DFCNTRL, (HDMAEN|SCSIEN|PRELOADEN); + } + call setjmp; + if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) != 0) { + test DFSTATUS, PRELOAD_AVAIL jz overrun_load_done; + call load_overrun_buf; + or DFCNTRL, PRELOADEN; +overrun_load_done: + test SEQINTSRC, CTXTDONE jnz pkt_overrun_end; + } else { + test DFFSXFRCTL, DFFBITBUCKET jz pkt_overrun_end; + } + test SSTAT2, NONPACKREQ jz return; +pkt_overrun_end: + or SCB_RESIDUAL_SGPTR, SG_OVERRUN_RESID; + test SEQINTSRC, CTXTDONE jz unexpected_nonpkt_phase; + dec SCB_FIFO_USE_COUNT; + or LONGJMP_ADDR[1], INVALID_ADDR; + test SCB_CONTROL, STATUS_RCVD jnz pkt_complete_scb_if_fifos_idle; + mvi DFFSXFRCTL, CLRCHN ret; + +if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) != 0) { +load_overrun_buf: + /* + * Load a dummy segment if preload space is available. + */ + mov HADDR[0], SHARED_DATA_ADDR; + add HADDR[1], PKT_OVERRUN_BUFOFFSET, SHARED_DATA_ADDR[1]; + mov ACCUM_SAVE, A; + clr A; + adc HADDR[2], A, SHARED_DATA_ADDR[2]; + adc HADDR[3], A, SHARED_DATA_ADDR[3]; + mov A, ACCUM_SAVE; + bmov HADDR[4], ALLZEROS, 4; + /* PKT_OVERRUN_BUFSIZE is a multiple of 256 */ + clr HCNT[0]; + mvi HCNT[1], ((PKT_OVERRUN_BUFSIZE >> 8) & 0xFF); + clr HCNT[2] ret; +} |