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freebsd-skq/sys/dev/aic7xxx/aic79xx.seq
Justin T. Gibbs 4164174aff aic79xx.c: 
aic79xx.seq:
	Convert the COMPLETE_DMA_SCB list to an "stailq".  This allows us to
	safely keep the SCB that is currently being DMA'ed back the host on
	the head of the list while processing completions off of the bus.  The
	newly completed SCBs are appended to the tail of the queue.   In the
	past, we just dequeued the SCB that was in flight from the list, but
	this could result in a lost completion should the host perform certain
	types of error recovery that must cancel all in-flight SCB DMA operations.

	Switch from using a 16bit completion entry, holding just the tag and the
	completion valid bit, to a 64bit completion entry that also contains a
	"status packet valid" indicator.  This solves two problems:
	  o The SCB DMA engine on at least Rev B. silicon does not properly deal
	    with a PCI disconnect that occurs at a non-64bit aligned offset in the
	    chips "source buffer".  When the transfer is resumed, the DMA engine
	    continues at the correct offset, but may wrap to the head of the buffer
	    causing duplicate completions to be reported to the host.  By using a
	    completion buffer in host memory that is 64bit aligned and using 64bit
	    completion entries, such disconnects should only occur at aligned addresses.
	    This assumes that the host bridge will only disconnect on cache-line
	    boundaries and that cache-lines are multpiles of 64bits.

	  o By embedding the status information in the completion entry we can avoid
	    an extra memory reference to the HSCB for commands that complete without
	    error.

	Use the comparison of a "host freeze count" and a "sequencer freeze count"
	to allow the host to process most SCBs that complete with non-zero status
	without having to clear critical sections.  Instead the host can just pause the
	sequencer, performs any necessary cleanup in the waiting for selection list,
	increments its freeze count on the controller, and unpauses.  This is only
	possible because the sequencer defers completions of SCBs with bad status
	until after all pending selections have completed.  The sequencer then avoids
	referencing any data structures the host may touch during completion of the
	SCB until the freeze counts match.

aic79xx.c:
	Change the strategy for allocating our sentinal HSCB for the QINFIFO.  In
	the past, this allocation was tacked onto the QOUTFIFO allocation.  Now that
	the qoutfifo has grown to accomodate larger completion entries, the old
	approach will result in a 64byte allocation that costs an extra page of
	coherent memory.  We now do this extra allocation via ahd_alloc_scbs()
	where the "unused space" can be used to allocate "normal" HSCBs.

	In our packetized busfree handler, use the ENSELO bit to differentiate
	between packetized and non-packetized unexpected busfree events that
	occur just after selection, but before the sequencer has had the oportunity
	to service the selection.

	When cleaning out the waiting for selection list, use the SCSI mode
	instead of the command channel mode.  The SCB pointer in the command
	channel mode may be referenced by the SCB dma engine even while the
	sequencer is paused, whereas the SCSI mode SCB pointer is only accessed
	by the sequencer.

	Print the "complete on qfreeze" sequencer SCB completion list in
	ahd_dump_card_state().  This list holds all SCB completions that are deferred
	until a pending select-out qfreeze event has taken effect.

aic79xx.h:
	Add definitions and structures to handle the new SCB completion scheme.

	Add a controller flag that indicates if the controller is in HostRAID
	mode.

aic79xx.reg:
	Remove macros used for toggling from one data fifo mode to the other.
	They have not been in use for some time.

	Add scratch ram fields for our new qfreeze count scheme, converting
	the complete dma list into an "stailq", and providing for the "complete
	on qfreeze" SCB completion list.  Some other fields were moved to retain
	proper field alignment (alignment >= field size in bytes).

aic79xx.seq:
	Add code to our idle loop to:
	  o Process deferred completions once a qfreeze event has taken full
	    effect.
	  o Thaw the queue once the sequencer and host qfreeze counts match.

	Generate 64bit completion entries passing the SCB_SGPTR field as the
	"good status" indicator.  The first bit in this field is only set if
	we have a valid status packet to send to the host.

	Convert the COMPLETE_DMA_SCB list to an "stailq".

	When using "setjmp" to register an idle loop handler, do not combine
	the "ret" with the block move to pop the stack address in the same
	instruction.  At least on the A, this results in a return to the setjmp
	caller, not to the new address at the top of the stack.  Since we want
	the latter (we want the newly registered handler to only be invoked from
	the idle loop), we must use a separate ret instruction.

	Add a few missing critical sections.

	Close a race condition that can occur on Rev A. silicon.  If both FIFOs
	happen to be allocated before the sequencer has a chance to service the
	FIFO that was allocated first, we must take special care to service the
	FIFO that is not active on the SCSI bus first.  This guarantees that a
	FIFO will be freed to handle any snapshot requests for the FIFO that is
	still on the bus.  Chosing the incorrect FIFO will result in deadlock.

	Update comments.

aic79xx_inline.h
	Correct the offset calculation for the syncing of our qoutfifo.

	Update ahd_check_cmdcmpltqueues() for the larger completion entries.

aic79xx_pci.c:
	Attach to HostRAID controllers by default.  In the future I may add a
	sysctl to modify the behavior, but since FreeBSD does not have any
	HostRAID drivers, failing to attach just results in more email and
	bug reports for the author.

MFC After: 1week
2004-02-04 16:38:38 +00:00

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/*
* Adaptec U320 device driver firmware for Linux and FreeBSD.
*
* Copyright (c) 1994-2001 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#118 $"
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;
END_CRITICAL;
call start_selection;
idle_loop_checkbus:
BEGIN_CRITICAL;
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 succesfully 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);
bmov REG0, SCBPTR, 2;
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;
mvi SCB_NEXT[1], SCB_LIST_NULL;
mvi SCB_NEXT2[1], SCB_LIST_NULL;
/* Increment our position in the QINFIFO. */
mov NONE, SNSCB_QOFF;
/*
* SCBs that want to send messages are always
* queued independently. This ensures that they
* are at the head of the SCB list to select out
* to a target and we will see the MK_MESSAGE flag.
*/
test SCB_CONTROL, MK_MESSAGE jnz first_new_target_scb;
shr SINDEX, 3, SCB_SCSIID;
and SINDEX, ~0x1;
mvi SINDEX[1], (WAITING_SCB_TAILS >> 8);
bmov DINDEX, SINDEX, 2;
bmov SCBPTR, SINDIR, 2;
bmov DINDIR, REG0, 2;
cmp SCBPTR[1], SCB_LIST_NULL je first_new_target_scb;
bmov SCB_NEXT, REG0, 2 ret;
first_new_target_scb:
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:
bmov WAITING_TID_HEAD, REG0, 2;
bmov WAITING_TID_TAIL, REG0, 2 ret;
END_CRITICAL;
scbdma_idle:
/*
* Give precedence to downloading new SCBs to execute
* unless select-outs are currently frozen.
*/
test SEQ_FLAGS2, SELECTOUT_QFROZEN jnz . + 2;
BEGIN_CRITICAL;
test QOFF_CTLSTA, NEW_SCB_AVAIL jnz fetch_new_scb;
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;
bmov SCBPTR, COMPLETE_SCB_HEAD, 2;
fill_qoutfifo_loop:
bmov CCSCBRAM, SCBPTR, 2;
mov CCSCBRAM, SCB_SGPTR[0];
bmov CCSCBRAM, ALLZEROS, 4;
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;
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 irregardless 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;
}
/*
* Requeue any SCBs not sent, to the tail of the waiting Q.
*/
cmp SCB_NEXT[1], SCB_LIST_NULL je select_out_list_done;
/*
* We know that neither the per-TID list nor the list of
* TIDs is empty. Use this knowledge to our advantage.
*/
bmov REG0, SCB_NEXT, 2;
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_list_done:
/*
* The whole list made it. Just clear our TID's tail pointer
* unless we were queued independently due to our need to
* send a message.
*/
test SCB_CONTROL, MK_MESSAGE jnz select_out_inc_tid_q;
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_phase;
test LQOSTAT1, LQOPHACHGINPKT jnz unexpected_nonpkt_phase;
/*
* 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 responce 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 reselction.
*/
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 orginal 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-existant 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 shaddow 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 shaddow is valid. If
* shaddow is not valid, keep running this FIFO until we
* have satisfied the transfer by loading segments and
* waiting for either shaddow 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 refernce
* 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;
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;
}
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