/*
* 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;
}