aic79xx.seq

linux-2.6.15.6

		 * 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 attepts
		 * 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 snapshot_data_valid;
		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;
END_CRITICAL;

/*
 * 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:
BEGIN_CRITICAL;
	/*
	 * 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;
}