Import siop, a replacement for the ncr SCSI driver, from NetBSD.

Written for NetBSD by Manuel Bouyer.

Tested with various cards on i386 and alpha.

Outstanding issue: doesn't work with PowerPC yet.

1 files changed, 2017 insertions, 0 deletions

diff --git a/sys/dev/ic/siop.c b/sys/dev/ic/siop.c
new file mode 100644
index 00000000000..c00398df08d
--- /dev/null
+++ b/sys/dev/ic/siop.c
@@ -0,0 +1,2017 @@
+/*	$OpenBSD: siop.c,v 1.1 2001/02/15 04:07:58 krw Exp $ */
+/*	$NetBSD: siop.c,v 1.39 2001/02/11 18:04:49 bouyer Exp $	*/
+
+/*
+ * Copyright (c) 2000 Manuel Bouyer.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Manuel Bouyer
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,     
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/* SYM53c7/8xx PCI-SCSI I/O Processors driver */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/malloc.h>
+#include <sys/buf.h>
+#include <sys/kernel.h>
+
+#include <machine/endian.h>
+#include <machine/bus.h>
+
+#include <dev/microcode/siop/siop.out>
+
+#include <scsi/scsi_all.h>
+#include <scsi/scsi_message.h>
+#include <scsi/scsiconf.h>
+
+#include <dev/ic/siopreg.h>
+#include <dev/ic/siopvar.h>
+#include <dev/ic/siopvar_common.h>
+
+#ifndef DEBUG
+#undef DEBUG
+#endif
+#undef SIOP_DEBUG
+#undef SIOP_DEBUG_DR
+#undef SIOP_DEBUG_INTR
+#undef SIOP_DEBUG_SCHED
+#undef DUMP_SCRIPT
+
+#define SIOP_STATS
+
+#ifndef SIOP_DEFAULT_TARGET
+#define SIOP_DEFAULT_TARGET 7
+#endif
+
+/* number of cmd descriptors per block */
+#define SIOP_NCMDPB (PAGE_SIZE / sizeof(struct siop_xfer))
+
+/* Number of scheduler slot (needs to match script) */
+#define SIOP_NSLOTS 40
+
+void	siop_reset __P((struct siop_softc *));
+void	siop_handle_reset __P((struct siop_softc *));
+int	siop_handle_qtag_reject __P((struct siop_cmd *));
+void	siop_scsicmd_end __P((struct siop_cmd *));
+void	siop_start __P((struct siop_softc *));
+void 	siop_timeout __P((void *));
+int	siop_scsicmd __P((struct scsi_xfer *));
+void	siop_dump_script __P((struct siop_softc *));
+int	siop_morecbd __P((struct siop_softc *));
+struct siop_lunsw *siop_get_lunsw __P((struct siop_softc *));
+void	siop_add_reselsw __P((struct siop_softc *, int));
+void	siop_update_scntl3 __P((struct siop_softc *, struct siop_target *));
+
+struct cfdriver siop_cd = {
+	NULL, "siop", DV_DULL
+};
+
+struct scsi_adapter siop_adapter = {
+	siop_scsicmd,
+	siop_minphys,
+	NULL,
+	NULL,
+};
+
+struct scsi_device siop_dev = {
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+};
+
+#ifdef SIOP_STATS
+static int siop_stat_intr = 0;
+static int siop_stat_intr_shortxfer = 0;
+static int siop_stat_intr_sdp = 0;
+static int siop_stat_intr_done = 0;
+static int siop_stat_intr_xferdisc = 0;
+static int siop_stat_intr_lunresel = 0;
+static int siop_stat_intr_qfull = 0;
+void siop_printstats __P((void));
+#define INCSTAT(x) x++
+#else
+#define INCSTAT(x) 
+#endif
+
+static __inline__ void siop_script_sync __P((struct siop_softc *, int));
+static __inline__ void
+siop_script_sync(sc, ops)
+	struct siop_softc *sc;
+	int ops;
+{
+	if ((sc->features & SF_CHIP_RAM) == 0)
+		bus_dmamap_sync(sc->sc_dmat, sc->sc_scriptdma, ops);
+}
+
+static __inline__ u_int32_t siop_script_read __P((struct siop_softc *, u_int));
+static __inline__ u_int32_t
+siop_script_read(sc, offset)
+	struct siop_softc *sc;
+	u_int offset;
+{
+	if (sc->features & SF_CHIP_RAM) {
+		return bus_space_read_4(sc->sc_ramt, sc->sc_ramh, offset * 4);
+	} else {
+		return letoh32(sc->sc_script[offset]);
+	}
+}
+
+static __inline__ void siop_script_write __P((struct siop_softc *, u_int,
+	u_int32_t));
+static __inline__ void
+siop_script_write(sc, offset, val)
+	struct siop_softc *sc;
+	u_int offset;
+	u_int32_t val;
+{
+	if (sc->features & SF_CHIP_RAM) {
+		bus_space_write_4(sc->sc_ramt, sc->sc_ramh, offset * 4, val);
+	} else {
+		sc->sc_script[offset] = htole32(val);
+	}
+}
+
+void
+siop_attach(sc)
+	struct siop_softc *sc;
+{
+	int error, i;
+	bus_dma_segment_t seg;
+	int rseg;
+
+	/*
+	 * Allocate DMA-safe memory for the script and map it.
+	 */
+	if ((sc->features & SF_CHIP_RAM) == 0) {
+		error = bus_dmamem_alloc(sc->sc_dmat, PAGE_SIZE, 
+		    PAGE_SIZE, 0, &seg, 1, &rseg, BUS_DMA_NOWAIT);
+		if (error) {
+			printf("%s: unable to allocate script DMA memory, "
+			    "error = %d\n", sc->sc_dev.dv_xname, error);
+			return;
+		}
+		error = bus_dmamem_map(sc->sc_dmat, &seg, rseg, PAGE_SIZE,
+		    (caddr_t *)&sc->sc_script, BUS_DMA_NOWAIT|BUS_DMA_COHERENT);
+		if (error) {
+			printf("%s: unable to map script DMA memory, "
+			    "error = %d\n", sc->sc_dev.dv_xname, error);
+			return;
+		}
+		error = bus_dmamap_create(sc->sc_dmat, PAGE_SIZE, 1,
+		    PAGE_SIZE, 0, BUS_DMA_NOWAIT, &sc->sc_scriptdma);
+		if (error) {
+			printf("%s: unable to create script DMA map, "
+			    "error = %d\n", sc->sc_dev.dv_xname, error);
+			return;
+		}
+		error = bus_dmamap_load(sc->sc_dmat, sc->sc_scriptdma,
+		    sc->sc_script, PAGE_SIZE, NULL, BUS_DMA_NOWAIT);
+		if (error) {
+			printf("%s: unable to load script DMA map, "
+			    "error = %d\n", sc->sc_dev.dv_xname, error);
+			return;
+		}
+		sc->sc_scriptaddr = sc->sc_scriptdma->dm_segs[0].ds_addr;
+		sc->ram_size = PAGE_SIZE;
+	}
+	TAILQ_INIT(&sc->free_list);
+	TAILQ_INIT(&sc->ready_list);
+	TAILQ_INIT(&sc->urgent_list);
+	TAILQ_INIT(&sc->cmds);
+	TAILQ_INIT(&sc->lunsw_list);
+	sc->sc_currschedslot = 0;
+#ifdef SIOP_DEBUG
+	printf("%s: script size = %d, PHY addr=0x%x, VIRT=%p\n",
+	    sc->sc_dev.dv_xname, (int)sizeof(siop_script),
+	    (u_int32_t)sc->sc_scriptaddr, sc->sc_script);
+#endif
+
+	sc->sc_link.adapter_softc = sc;
+	sc->sc_link.openings = 2;
+	sc->sc_link.adapter_buswidth =
+	    (sc->features & SF_BUS_WIDE) ? 16 : 8;
+	sc->sc_link.adapter_target = bus_space_read_1(sc->sc_rt,
+	    sc->sc_rh, SIOP_SCID);
+	if (sc->sc_link.adapter_target == 0 ||
+	    sc->sc_link.adapter_target >=
+	    sc->sc_link.adapter_buswidth)
+		sc->sc_link.adapter_target = SIOP_DEFAULT_TARGET;
+	sc->sc_link.adapter = &siop_adapter;
+	sc->sc_link.device = &siop_dev;
+	sc->sc_link.flags  = 0;
+
+	for (i = 0; i < 16; i++)
+		sc->targets[i] = NULL;
+
+	/* find min/max sync period for this chip */
+	sc->maxsync = 0;
+	sc->minsync = 255;
+	for (i = 0; i < sizeof(scf_period) / sizeof(scf_period[0]); i++) {
+		if (sc->clock_period != scf_period[i].clock)
+			continue;
+		if (sc->maxsync < scf_period[i].period)
+			sc->maxsync = scf_period[i].period;
+		if (sc->minsync > scf_period[i].period)
+			sc->minsync = scf_period[i].period;
+	}
+	if (sc->maxsync == 255 || sc->minsync == 0)
+		panic("siop: can't find my sync parameters\n");
+	/* Do a bus reset, so that devices fall back to narrow/async */
+	siop_resetbus(sc);
+	/*
+	 * siop_reset() will reset the chip, thus clearing pending interrupts
+	 */
+	siop_reset(sc);
+#ifdef DUMP_SCRIPT
+	siop_dump_script(sc);
+#endif
+
+	config_found((struct device*)sc, &sc->sc_link, scsiprint);
+}
+
+void
+siop_reset(sc)
+	struct siop_softc *sc;
+{
+	int i, j;
+	struct siop_lunsw *lunsw;
+
+	siop_common_reset(sc);
+
+	/* copy and patch the script */
+	if (sc->features & SF_CHIP_RAM) {
+		bus_space_write_region_4(sc->sc_ramt, sc->sc_ramh, 0,
+		    siop_script, sizeof(siop_script) / sizeof(siop_script[0]));
+		for (j = 0; j <
+		    (sizeof(E_abs_msgin_Used) / sizeof(E_abs_msgin_Used[0]));
+		    j++) {
+			bus_space_write_4(sc->sc_ramt, sc->sc_ramh,
+			    E_abs_msgin_Used[j] * 4,
+			    sc->sc_scriptaddr + Ent_msgin_space);
+		}
+	} else {
+		for (j = 0;
+		    j < (sizeof(siop_script) / sizeof(siop_script[0])); j++) {
+			sc->sc_script[j] = htole32(siop_script[j]);
+		}
+		for (j = 0; j <
+		    (sizeof(E_abs_msgin_Used) / sizeof(E_abs_msgin_Used[0]));
+		    j++) {
+			sc->sc_script[E_abs_msgin_Used[j]] =
+			    htole32(sc->sc_scriptaddr + Ent_msgin_space);
+		}
+	}
+	sc->script_free_lo = sizeof(siop_script) / sizeof(siop_script[0]);
+	sc->script_free_hi = sc->ram_size / 4;
+
+	/* free used and unused lun switches */
+	while((lunsw = TAILQ_FIRST(&sc->lunsw_list)) != NULL) {
+#ifdef SIOP_DEBUG
+		printf("%s: free lunsw at offset %d\n",
+				sc->sc_dev.dv_xname, lunsw->lunsw_off);
+#endif
+		TAILQ_REMOVE(&sc->lunsw_list, lunsw, next);
+		free(lunsw, M_DEVBUF);
+	}
+	TAILQ_INIT(&sc->lunsw_list);
+	/* restore reselect switch */
+	for (i = 0; i < sc->sc_link.adapter_buswidth; i++) {
+		if (sc->targets[i] == NULL)
+			continue;
+#ifdef SIOP_DEBUG
+		printf("%s: restore sw for target %d\n",
+				sc->sc_dev.dv_xname, i);
+#endif
+		free(sc->targets[i]->lunsw, M_DEVBUF);
+		sc->targets[i]->lunsw = siop_get_lunsw(sc);
+		if (sc->targets[i]->lunsw == NULL) {
+			printf("%s: can't alloc lunsw for target %d\n",
+			    sc->sc_dev.dv_xname, i);
+			break;
+		}
+		siop_add_reselsw(sc, i);
+	}
+
+	/* start script */
+	if ((sc->features & SF_CHIP_RAM) == 0) {
+		bus_dmamap_sync(sc->sc_dmat, sc->sc_scriptdma,
+		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+	}
+	bus_space_write_4(sc->sc_rt, sc->sc_rh, SIOP_DSP,
+	    sc->sc_scriptaddr + Ent_reselect);
+}
+
+#if 0
+#define CALL_SCRIPT(ent) do {\
+	printf ("start script DSA 0x%lx DSP 0x%lx\n", \
+	    siop_cmd->dsa, \
+	    sc->sc_scriptaddr + ent); \
+bus_space_write_4(sc->sc_rt, sc->sc_rh, SIOP_DSP, sc->sc_scriptaddr + ent); \
+} while (0)
+#else
+#define CALL_SCRIPT(ent) do {\
+bus_space_write_4(sc->sc_rt, sc->sc_rh, SIOP_DSP, sc->sc_scriptaddr + ent); \
+} while (0)
+#endif
+
+int
+siop_intr(v)
+	void *v;
+{
+	struct siop_softc *sc = v;
+	struct siop_target *siop_target;
+	struct siop_cmd *siop_cmd;
+	struct siop_lun *siop_lun;
+	struct scsi_xfer *xs;
+	int istat, sist, sstat1, dstat;
+	u_int32_t irqcode;
+	int need_reset = 0;
+	int offset, target, lun, tag;
+	bus_addr_t dsa;
+	struct siop_cbd *cbdp;
+	int freetarget = 0;
+	int restart = 0;
+
+	istat = bus_space_read_1(sc->sc_rt, sc->sc_rh, SIOP_ISTAT);
+	if ((istat & (ISTAT_INTF | ISTAT_DIP | ISTAT_SIP)) == 0)
+		return 0;
+	INCSTAT(siop_stat_intr);
+	if (istat & ISTAT_INTF) {
+		printf("INTRF\n");
+		bus_space_write_1(sc->sc_rt, sc->sc_rh, SIOP_ISTAT, ISTAT_INTF);
+	}
+	/* use DSA to find the current siop_cmd */
+	dsa = bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSA);
+	for (cbdp = TAILQ_FIRST(&sc->cmds); cbdp != NULL;
+	    cbdp = TAILQ_NEXT(cbdp, next)) {
+		if (dsa >= cbdp->xferdma->dm_segs[0].ds_addr &&
+	    	    dsa < cbdp->xferdma->dm_segs[0].ds_addr + PAGE_SIZE) {
+			dsa -= cbdp->xferdma->dm_segs[0].ds_addr;
+			siop_cmd = &cbdp->cmds[dsa / sizeof(struct siop_xfer)];
+			siop_table_sync(siop_cmd,
+			    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
+			break;
+		}
+	} 
+	if (cbdp == NULL) {
+		siop_cmd = NULL;
+	}
+	if (siop_cmd) {
+		xs = siop_cmd->xs;
+		siop_target = siop_cmd->siop_target;
+		target = siop_cmd->xs->sc_link->target;
+		lun = siop_cmd->xs->sc_link->lun;
+		tag = siop_cmd->tag;
+		siop_lun = siop_target->siop_lun[lun];
+#ifdef DIAGNOSTIC
+		if (siop_cmd->status != CMDST_ACTIVE &&
+		    siop_cmd->status != CMDST_SENSE_ACTIVE) {
+			printf("siop_cmd (lun %d) not active (%d)\n",
+				lun, siop_cmd->status);
+			xs = NULL;
+			siop_target = NULL;
+			target = -1;
+			lun = -1;
+			tag = -1;
+			siop_lun = NULL;
+			siop_cmd = NULL;
+		} else if (siop_lun->siop_tag[tag].active != siop_cmd) {
+			printf("siop_cmd (lun %d tag %d) not in siop_lun "
+			    "active (%p != %p)\n", lun, tag, siop_cmd,
+			    siop_lun->siop_tag[tag].active);
+		}
+#endif
+	} else {
+		xs = NULL;
+		siop_target = NULL;
+		target = -1;
+		lun = -1;
+		tag = -1;
+		siop_lun = NULL;
+	}
+	if (istat & ISTAT_DIP) {
+		dstat = bus_space_read_1(sc->sc_rt, sc->sc_rh, SIOP_DSTAT);
+		if (dstat & DSTAT_SSI) {
+			printf("single step dsp 0x%08x dsa 0x08%x\n",
+			    (int)(bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSP) -
+			    sc->sc_scriptaddr),
+			    bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSA));
+			if ((dstat & ~(DSTAT_DFE | DSTAT_SSI)) == 0 &&
+			    (istat & ISTAT_SIP) == 0) {
+				bus_space_write_1(sc->sc_rt, sc->sc_rh,
+				    SIOP_DCNTL, bus_space_read_1(sc->sc_rt,
+				    sc->sc_rh, SIOP_DCNTL) | DCNTL_STD);
+			}
+			return 1;
+		}
+		if (dstat & ~(DSTAT_SIR | DSTAT_DFE | DSTAT_SSI)) {
+		printf("DMA IRQ:");
+		if (dstat & DSTAT_IID)
+			printf(" Illegal instruction");
+		if (dstat & DSTAT_ABRT)
+			printf(" abort");
+		if (dstat & DSTAT_BF)
+			printf(" bus fault");
+		if (dstat & DSTAT_MDPE)
+			printf(" parity");
+		if (dstat & DSTAT_DFE)
+			printf(" dma fifo empty");
+		printf(", DSP=0x%x DSA=0x%x: ",
+		    (int)(bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSP) -
+		    sc->sc_scriptaddr),
+		    bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSA));
+		if (siop_cmd)
+			printf("last msg_in=0x%x status=0x%x\n",
+			    siop_cmd->siop_tables.msg_in[0],
+			    letoh32(siop_cmd->siop_tables.status));
+		else 
+			printf("%s: current DSA invalid\n",
+			    sc->sc_dev.dv_xname);
+		need_reset = 1;
+		}
+	}
+	if (istat & ISTAT_SIP) {
+		if (istat & ISTAT_DIP)
+			delay(10);
+		/*
+		 * Can't read sist0 & sist1 independantly, or we have to
+		 * insert delay
+		 */
+		sist = bus_space_read_2(sc->sc_rt, sc->sc_rh, SIOP_SIST0);
+		sstat1 = bus_space_read_1(sc->sc_rt, sc->sc_rh, SIOP_SSTAT1);
+#ifdef SIOP_DEBUG_INTR
+		printf("scsi interrupt, sist=0x%x sstat1=0x%x "
+		    "DSA=0x%x DSP=0x%lx\n", sist,
+		    bus_space_read_1(sc->sc_rt, sc->sc_rh, SIOP_SSTAT1),
+		    bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSA),
+		    (u_long)(bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSP) -
+		    sc->sc_scriptaddr));
+#endif
+		if (sist & SIST0_RST) {
+			siop_handle_reset(sc);
+			siop_start(sc);
+			/* no table to flush here */
+			return 1;
+		}
+		if (sist & SIST0_SGE) {
+			if (siop_cmd)
+				sc_print_addr(xs->sc_link);
+			else
+				printf("%s:", sc->sc_dev.dv_xname);
+			printf("scsi gross error\n");
+			goto reset;
+		}
+		if ((sist & SIST0_MA) && need_reset == 0) {
+			if (siop_cmd) { 
+				int scratcha0;
+				dstat = bus_space_read_1(sc->sc_rt, sc->sc_rh,
+				    SIOP_DSTAT);
+				/*
+				 * first restore DSA, in case we were in a S/G
+				 * operation.
+				 */
+				bus_space_write_4(sc->sc_rt, sc->sc_rh,
+				    SIOP_DSA, siop_cmd->dsa);
+				scratcha0 = bus_space_read_1(sc->sc_rt,
+				    sc->sc_rh, SIOP_SCRATCHA);
+				switch (sstat1 & SSTAT1_PHASE_MASK) {
+				case SSTAT1_PHASE_STATUS:
+				/*
+				 * previous phase may be aborted for any reason
+				 * ( for example, the target has less data to
+				 * transfer than requested). Just go to status
+				 * and the command should terminate.
+				 */
+					INCSTAT(siop_stat_intr_shortxfer);
+					if ((dstat & DSTAT_DFE) == 0)
+						siop_clearfifo(sc);
+					/* no table to flush here */
+					CALL_SCRIPT(Ent_status);
+					return 1;
+				case SSTAT1_PHASE_MSGIN:
+					/*
+					 * target may be ready to disconnect
+					 * Save data pointers just in case.
+					 */
+					INCSTAT(siop_stat_intr_xferdisc);
+					if (scratcha0 & A_flag_data)
+						siop_sdp(siop_cmd);
+					else if ((dstat & DSTAT_DFE) == 0)
+						siop_clearfifo(sc);
+					bus_space_write_1(sc->sc_rt, sc->sc_rh,
+					    SIOP_SCRATCHA,
+					    scratcha0 & ~A_flag_data);
+					siop_table_sync(siop_cmd,
+					    BUS_DMASYNC_PREREAD |
+					    BUS_DMASYNC_PREWRITE);
+					CALL_SCRIPT(Ent_msgin);
+					return 1;
+				}
+				printf("%s: unexpected phase mismatch %d\n",
+				    sc->sc_dev.dv_xname,
+				    sstat1 & SSTAT1_PHASE_MASK);
+			} else {
+				printf("%s: phase mismatch without command\n",
+				    sc->sc_dev.dv_xname);
+			}
+			need_reset = 1;
+		}
+		if (sist & SIST0_PAR) {
+			/* parity error, reset */
+			if (siop_cmd)
+				sc_print_addr(xs->sc_link);
+			else
+				printf("%s:", sc->sc_dev.dv_xname);
+			printf("parity error\n");
+			goto reset;
+		}
+		if ((sist & (SIST1_STO << 8)) && need_reset == 0) {
+			/* selection time out, assume there's no device here */
+			if (siop_cmd) {
+				siop_cmd->status = CMDST_DONE;
+				xs->error = XS_SELTIMEOUT;
+				freetarget = 1;
+				goto end;
+			} else {
+				printf("%s: selection timeout without "
+				    "command\n", sc->sc_dev.dv_xname);
+				need_reset = 1;
+			}
+		}
+		if (sist & SIST0_UDC) {
+			/*
+			 * unexpected disconnect. Usually the target signals
+			 * a fatal condition this way. Attempt to get sense.
+			 */
+			 if (siop_cmd) {
+				siop_cmd->siop_tables.status =
+				    htole32(SCSI_CHECK);
+				goto end;
+			}
+			printf("%s: unexpected disconnect without "
+			    "command\n", sc->sc_dev.dv_xname);
+			goto reset;
+		}
+		if (sist & (SIST1_SBMC << 8)) {
+			/* SCSI bus mode change */
+			if (siop_modechange(sc) == 0 || need_reset == 1)
+				goto reset;
+			if ((istat & ISTAT_DIP) && (dstat & DSTAT_SIR)) {
+				/*
+				 * we have a script interrupt, it will
+				 * restart the script.
+				 */
+				goto scintr;
+			}
+			/*
+			 * else we have to restart it ourselve, at the
+			 * interrupted instruction.
+			 */
+			bus_space_write_4(sc->sc_rt, sc->sc_rh, SIOP_DSP,
+			    bus_space_read_4(sc->sc_rt, sc->sc_rh,
+			    SIOP_DSP) - 8);
+			return 1;
+		}
+		/* Else it's an unhandled exeption (for now). */
+		printf("%s: unhandled scsi interrupt, sist=0x%x sstat1=0x%x "
+		    "DSA=0x%x DSP=0x%x\n", sc->sc_dev.dv_xname, sist,
+		    bus_space_read_1(sc->sc_rt, sc->sc_rh, SIOP_SSTAT1),
+		    bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSA),
+		    (int)(bus_space_read_4(sc->sc_rt, sc->sc_rh, SIOP_DSP) -
+		    sc->sc_scriptaddr));
+		if (siop_cmd) {
+			siop_cmd->status = CMDST_DONE;
+			xs->error = XS_SELTIMEOUT;
+			goto end;
+		}
+		need_reset = 1;
+	}
+	if (need_reset) {
+reset:
+		/* fatal error, reset the bus */
+		siop_resetbus(sc);
+		/* no table to flush here */
+		return 1;
+	}
+
+scintr:
+	if ((istat & ISTAT_DIP) && (dstat & DSTAT_SIR)) { /* script interrupt */
+		irqcode = bus_space_read_4(sc->sc_rt, sc->sc_rh,
+		    SIOP_DSPS);
+#ifdef SIOP_DEBUG_INTR
+		printf("script interrupt 0x%x\n", irqcode);
+#endif
+		/*
+		 * no command, or an inactive command is only valid for a
+		 * reselect interrupt
+		 */
+		if ((irqcode & 0x80) == 0) {
+			if (siop_cmd == NULL) {
+				printf("%s: script interrupt (0x%x) with
+				    invalid DSA !!!\n", sc->sc_dev.dv_xname,
+				    irqcode);
+				goto reset;
+			}
+			if (siop_cmd->status != CMDST_ACTIVE &&
+			    siop_cmd->status != CMDST_SENSE_ACTIVE) {
+				printf("%s: command with invalid status "
+				    "(IRQ code 0x%x current status %d) !\n",
+				    sc->sc_dev.dv_xname,
+				    irqcode, siop_cmd->status);
+				xs = NULL;
+			}
+		}
+		switch(irqcode) {
+		case A_int_err:
+			printf("error, DSP=0x%x\n",
+			    (int)(bus_space_read_4(sc->sc_rt, sc->sc_rh,
+			    SIOP_DSP) - sc->sc_scriptaddr));
+			if (xs) {
+				xs->error = XS_SELTIMEOUT;
+				goto end;
+			} else {
+				goto reset;
+			}
+		case A_int_reseltarg:
+			printf("%s: reselect with invalid target\n",
+				    sc->sc_dev.dv_xname);
+			goto reset;
+		case A_int_resellun: 
+			INCSTAT(siop_stat_intr_lunresel);
+			target = bus_space_read_1(sc->sc_rt, sc->sc_rh,
+			    SIOP_SCRATCHA) & 0xf;
+			lun = bus_space_read_1(sc->sc_rt, sc->sc_rh,
+			    SIOP_SCRATCHA + 1);
+			tag = bus_space_read_1(sc->sc_rt, sc->sc_rh,
+			    SIOP_SCRATCHA + 2);
+			siop_target = sc->targets[target];
+			if (siop_target == NULL) {
+				printf("%s: reselect with invalid "
+				    "target %d\n", sc->sc_dev.dv_xname, target);
+				goto reset;
+			}
+			siop_lun = siop_target->siop_lun[lun];
+			if (siop_lun == NULL) {
+				printf("%s: target %d reselect with invalid "
+				    "lun %d\n", sc->sc_dev.dv_xname,
+				    target, lun);
+				goto reset;
+			}
+			if (siop_lun->siop_tag[tag].active == NULL) {
+				printf("%s: target %d lun %d tag %d reselect "
+				    "without command\n", sc->sc_dev.dv_xname,
+				    target, lun, tag);
+				goto reset;
+			}
+			siop_cmd = siop_lun->siop_tag[tag].active;
+			bus_space_write_4(sc->sc_rt, sc->sc_rh, SIOP_DSP,
+			    siop_cmd->dsa + sizeof(struct siop_xfer_common) +
+			    Ent_ldsa_reload_dsa);
+			siop_table_sync(siop_cmd, BUS_DMASYNC_PREWRITE);
+			return 1;
+		case A_int_reseltag:
+			printf("%s: reselect with invalid tag\n",
+				    sc->sc_dev.dv_xname);
+			goto reset;
+		case A_int_msgin:
+		{
+			int msgin = bus_space_read_1(sc->sc_rt, sc->sc_rh,
+			    SIOP_SFBR);
+			if (msgin == MSG_MESSAGE_REJECT) {
+				int msg, extmsg;
+				if (siop_cmd->siop_tables.msg_out[0] & 0x80) {
+					/*
+					 * message was part of a identify +
+					 * something else. Identify shoudl't
+					 * have been rejected.
+					 */
+					msg = siop_cmd->siop_tables.msg_out[1];
+					extmsg =
+					    siop_cmd->siop_tables.msg_out[3];
+				} else {
+					msg = siop_cmd->siop_tables.msg_out[0];
+					extmsg =
+					    siop_cmd->siop_tables.msg_out[2];
+				}
+				if (msg == MSG_MESSAGE_REJECT) {
+					/* MSG_REJECT  for a MSG_REJECT  !*/
+					if (xs)
+						sc_print_addr(xs->sc_link);
+					else
+						printf("%s: ",
+						   sc->sc_dev.dv_xname);
+					printf("our reject message was "
+					    "rejected\n");
+					goto reset;
+				}
+				if (msg == MSG_EXTENDED &&
+				    extmsg == MSG_EXT_WDTR) {
+					/* WDTR rejected, initiate sync */
+					printf("%s: target %d using 8bit "
+					    "transfers\n", sc->sc_dev.dv_xname,
+					    target);
+					if ((siop_target->flags & TARF_SYNC)
+					    == 0) {
+						siop_target->status = TARST_OK;
+						/* no table to flush here */
+						CALL_SCRIPT(Ent_msgin_ack);
+						return 1;
+					}
+					siop_target->status = TARST_SYNC_NEG;
+					siop_sdtr_msg(siop_cmd, 0,
+					    sc->minsync, sc->maxoff);
+					siop_table_sync(siop_cmd,
+					    BUS_DMASYNC_PREREAD |
+					    BUS_DMASYNC_PREWRITE);
+					CALL_SCRIPT(Ent_send_msgout);
+					return 1;
+				} else if (msg == MSG_EXTENDED &&
+				    extmsg == MSG_EXT_SDTR) {
+					/* sync rejected */
+					printf("%s: target %d asynchronous\n",
+					    sc->sc_dev.dv_xname,
+					    target);
+					siop_target->status = TARST_OK;
+					/* no table to flush here */
+					CALL_SCRIPT(Ent_msgin_ack);
+					return 1;
+				} else if (msg == MSG_SIMPLE_Q_TAG || 
+				    msg == MSG_HEAD_OF_Q_TAG ||
+				    msg == MSG_ORDERED_Q_TAG) {
+					if (siop_handle_qtag_reject(
+					    siop_cmd) == -1)
+						goto reset;
+					CALL_SCRIPT(Ent_msgin_ack);
+					return 1;
+				}
+				if (xs)
+					sc_print_addr(xs->sc_link);
+				else
+					printf("%s: ", sc->sc_dev.dv_xname);
+				if (msg == MSG_EXTENDED) {
+					printf("scsi message reject, extended "
+					    "message sent was 0x%x\n", extmsg);
+				} else {
+					printf("scsi message reject, message "
+					    "sent was 0x%x\n", msg);
+				}
+				/* no table to flush here */
+				CALL_SCRIPT(Ent_msgin_ack);
+				return 1;
+			}
+			if (xs)
+				sc_print_addr(xs->sc_link);
+			else
+				printf("%s: ", sc->sc_dev.dv_xname);
+			printf("unhandled message 0x%x\n",
+			    siop_cmd->siop_tables.msg_in[0]);
+			siop_cmd->siop_tables.msg_out[0] = MSG_MESSAGE_REJECT;
+			siop_cmd->siop_tables.t_msgout.count= htole32(1);
+			siop_table_sync(siop_cmd,
+			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+			CALL_SCRIPT(Ent_send_msgout);
+			return 1;
+		}
+		case A_int_extmsgin:
+#ifdef SIOP_DEBUG_INTR
+			printf("extended message: msg 0x%x len %d\n",
+			    siop_cmd->siop_tables.msg_in[2], 
+			    siop_cmd->siop_tables.msg_in[1]);
+#endif
+			if (siop_cmd->siop_tables.msg_in[1] > 6)
+				printf("%s: extended message too big (%d)\n",
+				    sc->sc_dev.dv_xname,
+				    siop_cmd->siop_tables.msg_in[1]);
+			siop_cmd->siop_tables.t_extmsgdata.count =
+			    htole32(siop_cmd->siop_tables.msg_in[1] - 1);
+			siop_table_sync(siop_cmd,
+			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+			CALL_SCRIPT(Ent_get_extmsgdata);
+			return 1;
+		case A_int_extmsgdata:
+#ifdef SIOP_DEBUG_INTR
+			{
+			int i;
+			printf("extended message: 0x%x, data:",
+			    siop_cmd->siop_tables.msg_in[2]);
+			for (i = 3; i < 2 + siop_cmd->siop_tables.msg_in[1];
+			    i++)
+				printf(" 0x%x",
+				    siop_cmd->siop_tables.msg_in[i]);
+			printf("\n");
+			}
+#endif
+			if (siop_cmd->siop_tables.msg_in[2] == MSG_EXT_WDTR) {
+				switch (siop_wdtr_neg(siop_cmd)) {
+				case SIOP_NEG_MSGOUT:
+					siop_update_scntl3(sc,
+					    siop_cmd->siop_target);
+					siop_table_sync(siop_cmd,
+					    BUS_DMASYNC_PREREAD |
+					    BUS_DMASYNC_PREWRITE);
+					CALL_SCRIPT(Ent_send_msgout);
+					return(1);
+				case SIOP_NEG_ACK:
+					siop_update_scntl3(sc,
+					    siop_cmd->siop_target);
+					CALL_SCRIPT(Ent_msgin_ack);
+					return(1);
+				default:
+					panic("invalid retval from "
+					    "siop_wdtr_neg()");
+				}
+				return(1);
+			}
+			if (siop_cmd->siop_tables.msg_in[2] == MSG_EXT_SDTR) {
+				switch (siop_sdtr_neg(siop_cmd)) {
+				case SIOP_NEG_MSGOUT:
+					siop_update_scntl3(sc,
+					    siop_cmd->siop_target);
+					siop_table_sync(siop_cmd,
+					    BUS_DMASYNC_PREREAD |
+					    BUS_DMASYNC_PREWRITE);
+					CALL_SCRIPT(Ent_send_msgout);
+					return(1);
+				case SIOP_NEG_ACK:
+					siop_update_scntl3(sc,
+					    siop_cmd->siop_target);
+					CALL_SCRIPT(Ent_msgin_ack);
+					return(1);
+				default:
+					panic("invalid retval from "
+					    "siop_wdtr_neg()");
+				}
+				return(1);
+			}
+			/* send a message reject */
+			siop_cmd->siop_tables.msg_out[0] = MSG_MESSAGE_REJECT;
+			siop_cmd->siop_tables.t_msgout.count = htole32(1);
+			siop_table_sync(siop_cmd,
+			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+			CALL_SCRIPT(Ent_send_msgout);
+			return 1;
+		case A_int_disc:
+			INCSTAT(siop_stat_intr_sdp);
+			offset = bus_space_read_1(sc->sc_rt, sc->sc_rh,
+			    SIOP_SCRATCHA + 1);
+#ifdef SIOP_DEBUG_DR
+			printf("disconnect offset %d\n", offset);
+#endif
+			if (offset > SIOP_NSG) {
+				printf("%s: bad offset for disconnect (%d)\n",
+				    sc->sc_dev.dv_xname, offset);
+				goto reset;
+			}
+			/* 
+			 * offset == SIOP_NSG may be a valid condition if
+			 * we get a sdp when the xfer is done.
+			 * Don't call memmove in this case.
+			 */
+			if (offset < SIOP_NSG) {
+				bcopy(&siop_cmd->siop_tables.data[offset],
+				    &siop_cmd->siop_tables.data[0],
+				    (SIOP_NSG - offset) * sizeof(scr_table_t));
+				siop_table_sync(siop_cmd,
+				    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+			}
+			CALL_SCRIPT(Ent_script_sched);
+			/* check if we can put some command in scheduler */
+			siop_start(sc);
+			return 1;
+		case A_int_resfail:
+			printf("reselect failed\n");
+			CALL_SCRIPT(Ent_script_sched);
+			return  1;
+		case A_int_done:
+			if (xs == NULL) {
+				printf("%s: done without command, DSA=0x%lx\n",
+				    sc->sc_dev.dv_xname, (u_long)siop_cmd->dsa);
+				siop_cmd->status = CMDST_FREE;
+				siop_start(sc);
+				CALL_SCRIPT(Ent_script_sched);
+				return 1;
+			}
+#ifdef SIOP_DEBUG_INTR
+			printf("done, DSA=0x%lx target id 0x%x last msg "
+			    "in=0x%x status=0x%x\n", (u_long)siop_cmd->dsa,
+			    letoh32(siop_cmd->siop_tables.id),
+			    siop_cmd->siop_tables.msg_in[0],
+			    letoh32(siop_cmd->siop_tables.status));
+#endif
+			INCSTAT(siop_stat_intr_done);
+			if (siop_cmd->status == CMDST_SENSE_ACTIVE)
+				siop_cmd->status = CMDST_SENSE_DONE;
+			else
+				siop_cmd->status = CMDST_DONE;
+			goto end;
+		default:
+			printf("unknown irqcode %x\n", irqcode);
+			if (xs) {
+				xs->error = XS_SELTIMEOUT;
+				goto end;
+			}
+			goto reset;
+		}
+		return 1;
+	}
+	/* We just should't get there */
+	panic("siop_intr: I shouldn't be there !");
+	return 1;
+end:
+	/*
+	 * restart the script now if command completed properly
+	 * Otherwise wait for siop_scsicmd_end(), it may need to put
+	 * a cmd in front of the queue
+	 */
+	if (letoh32(siop_cmd->siop_tables.status) == SCSI_OK &&
+	    TAILQ_FIRST(&sc->urgent_list) != NULL)
+		CALL_SCRIPT(Ent_script_sched);
+	else
+		restart = 1;
+	siop_scsicmd_end(siop_cmd);
+	siop_lun->siop_tag[tag].active = NULL;
+	if (siop_cmd->status == CMDST_FREE) {
+		TAILQ_INSERT_TAIL(&sc->free_list, siop_cmd, next);
+		siop_lun->lun_flags &= ~SIOP_LUNF_FULL;
+		if (freetarget && siop_target->status == TARST_PROBING)
+			siop_del_dev(sc, target, lun);
+	}
+	siop_start(sc);
+	if (restart)
+		CALL_SCRIPT(Ent_script_sched);
+	return 1;
+}
+
+void
+siop_scsicmd_end(siop_cmd)
+	struct siop_cmd *siop_cmd;
+{
+	struct scsi_xfer *xs = siop_cmd->xs;
+	struct siop_softc *sc = siop_cmd->siop_sc;
+
+	switch(letoh32(siop_cmd->siop_tables.status)) {
+	case SCSI_OK:
+		xs->error = (siop_cmd->status == CMDST_DONE) ?
+		    XS_NOERROR : XS_SENSE;
+		break;
+	case SCSI_BUSY:
+		xs->error = XS_BUSY;
+		break;
+	case SCSI_CHECK:
+		if (siop_cmd->status == CMDST_SENSE_DONE) {
+			/* request sense on a request sense ? */
+			printf("request sense failed\n");
+			xs->error = XS_DRIVER_STUFFUP;
+		} else {
+			siop_cmd->status = CMDST_SENSE;
+		}
+		break;
+	case SCSI_QUEUE_FULL:
+		{
+		struct siop_lun *siop_lun = siop_cmd->siop_target->siop_lun[
+		    xs->sc_link->lun];
+		/*
+		 * device didn't queue the command. We have to
+		 * retry it.
+		 * We insert it in the urgent list, hoping to preserve order.
+		 * But unfortunably, commands already in the scheduler may
+		 * be accepted before this one.
+		 * Also remember the condition, to avoid starting new commands
+		 * for this device before one is done.
+		 */
+		INCSTAT(siop_stat_intr_qfull);
+#ifdef SIOP_DEBUG
+		printf("%s:%d:%d: queue full (tag %d)\n", sc->sc_dev.dv_xname,
+		    xs->sc_link->target,
+		    xs->sc_link->lun, siop_cmd->tag);
+#endif
+		timeout_del(&xs->stimeout);
+		siop_lun->lun_flags |= SIOP_LUNF_FULL;
+		siop_cmd->status = CMDST_READY;
+		siop_setuptables(siop_cmd);
+		TAILQ_INSERT_TAIL(&sc->urgent_list, siop_cmd, next);
+		return;
+		}
+	case SCSI_SIOP_NOCHECK:
+		/*
+		 * don't check status, xs->error is already valid
+		 */
+		break;
+	case SCSI_SIOP_NOSTATUS:
+		/*
+		 * the status byte was not updated, cmd was
+		 * aborted
+		 */
+		xs->error = XS_SELTIMEOUT;
+		break;
+	default:
+		xs->error = XS_DRIVER_STUFFUP;
+	}
+	if (siop_cmd->status != CMDST_SENSE_DONE &&
+	    xs->flags & (SCSI_DATA_IN | SCSI_DATA_OUT)) {
+		bus_dmamap_sync(sc->sc_dmat, siop_cmd->dmamap_data,
+		    (xs->flags & SCSI_DATA_IN) ?
+		    BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
+		bus_dmamap_unload(sc->sc_dmat, siop_cmd->dmamap_data);
+	}
+	bus_dmamap_unload(sc->sc_dmat, siop_cmd->dmamap_cmd);
+	if (siop_cmd->status == CMDST_SENSE) {
+		/* issue a request sense for this target */
+		int error;
+		siop_cmd->rs_cmd.opcode = REQUEST_SENSE;
+		siop_cmd->rs_cmd.byte2 = xs->sc_link->lun << 5;
+		siop_cmd->rs_cmd.unused[0] = siop_cmd->rs_cmd.unused[1] = 0;
+		siop_cmd->rs_cmd.length = sizeof(struct scsi_sense_data);
+		siop_cmd->rs_cmd.control = 0;
+		siop_cmd->flags &= ~CMDFL_TAG;
+		error = bus_dmamap_load(sc->sc_dmat, siop_cmd->dmamap_cmd,
+		    &siop_cmd->rs_cmd, sizeof(struct scsi_sense),
+		    NULL, BUS_DMA_NOWAIT);
+		if (error) {
+			printf("%s: unable to load cmd DMA map: %d",
+			    sc->sc_dev.dv_xname, error);
+			xs->error = XS_DRIVER_STUFFUP;
+			goto out;
+		}
+		error = bus_dmamap_load(sc->sc_dmat, siop_cmd->dmamap_data,
+		    &xs->sense, sizeof(struct scsi_sense_data),
+		    NULL, BUS_DMA_NOWAIT);
+		if (error) {
+			printf("%s: unable to load sense DMA map: %d",
+			    sc->sc_dev.dv_xname, error);
+			xs->error = XS_DRIVER_STUFFUP;
+			bus_dmamap_unload(sc->sc_dmat, siop_cmd->dmamap_cmd);
+			goto out;
+		}
+		bus_dmamap_sync(sc->sc_dmat, siop_cmd->dmamap_data,
+		    BUS_DMASYNC_PREREAD);
+		bus_dmamap_sync(sc->sc_dmat, siop_cmd->dmamap_cmd,
+		    BUS_DMASYNC_PREWRITE);
+
+		siop_setuptables(siop_cmd);
+		/* arrange for the cmd to be handled now */
+		TAILQ_INSERT_HEAD(&sc->urgent_list, siop_cmd, next);
+		return;
+	} else if (siop_cmd->status == CMDST_SENSE_DONE) {
+		bus_dmamap_sync(sc->sc_dmat, siop_cmd->dmamap_data,
+		    BUS_DMASYNC_POSTREAD);
+		bus_dmamap_unload(sc->sc_dmat, siop_cmd->dmamap_data);
+	}
+out:
+	timeout_del(&siop_cmd->xs->stimeout);
+	siop_cmd->status = CMDST_FREE;
+	xs->flags |= ITSDONE;
+	xs->resid = 0;
+	if ((xs->flags & SCSI_POLL) == 0)
+		scsi_done (xs);
+}
+
+/*
+ * handle a rejected queue tag message: the command will run untagged,
+ * has to adjust the reselect script.
+ */
+int
+siop_handle_qtag_reject(siop_cmd)
+	struct siop_cmd *siop_cmd;
+{
+	struct siop_softc *sc = siop_cmd->siop_sc;
+	int target = siop_cmd->xs->sc_link->target;
+	int lun = siop_cmd->xs->sc_link->lun;
+	int tag = siop_cmd->siop_tables.msg_out[2];
+	struct siop_lun *siop_lun = sc->targets[target]->siop_lun[lun];
+
+#ifdef SIOP_DEBUG
+	printf("%s:%d:%d: tag message %d (%d) rejected (status %d)\n",
+	    sc->sc_dev.dv_xname, target, lun, tag, siop_cmd->tag,
+	    siop_cmd->status);
+#endif
+
+	if (siop_lun->siop_tag[0].active != NULL) {
+		printf("%s: untagged command already running for target %d "
+		    "lun %d (status %d)\n", sc->sc_dev.dv_xname, target, lun,
+		    siop_lun->siop_tag[0].active->status);
+		return -1;
+	}
+	/* clear tag slot */
+	siop_lun->siop_tag[tag].active = NULL;
+	/* add command to non-tagged slot */
+	siop_lun->siop_tag[0].active = siop_cmd;
+	siop_cmd->tag = 0;
+	/* adjust reselect script if there is one */
+	if (siop_lun->siop_tag[0].reseloff > 0) {
+		siop_script_write(sc,
+		    siop_lun->siop_tag[0].reseloff + 1,
+		    siop_cmd->dsa + sizeof(struct siop_xfer_common) +
+		    Ent_ldsa_reload_dsa);
+		siop_table_sync(siop_cmd, BUS_DMASYNC_PREWRITE);
+	}
+	return 0;
+}
+
+/*
+ * handle a bus reset: reset chip, unqueue all active commands, free all
+ * target struct and report loosage to upper layer.
+ * As the upper layer may requeue immediatly we have to first store
+ * all active commands in a temporary queue.
+ */
+void
+siop_handle_reset(sc)
+	struct siop_softc *sc;
+{
+	struct cmd_list reset_list;
+	struct siop_cmd *siop_cmd, *next_siop_cmd;
+	struct siop_lun *siop_lun;
+	int target, lun, tag;
+	/*
+	 * scsi bus reset. reset the chip and restart
+	 * the queue. Need to clean up all active commands
+	 */
+	printf("%s: scsi bus reset\n", sc->sc_dev.dv_xname);
+	/* stop, reset and restart the chip */
+	siop_reset(sc);
+	TAILQ_INIT(&reset_list);
+	/*
+	 * Process all commands: first commmands being executed
+	 */
+	for (target = 0; target < sc->sc_link.adapter_buswidth;
+	    target++) {
+		if (sc->targets[target] == NULL)
+			continue;
+		for (lun = 0; lun < 8; lun++) {
+			siop_lun = sc->targets[target]->siop_lun[lun];
+			if (siop_lun == NULL)
+				continue;
+			siop_lun->lun_flags &= ~SIOP_LUNF_FULL;
+			for (tag = 0; tag <
+			    ((sc->targets[target]->flags & TARF_TAG) ?
+			    SIOP_NTAG : 1);
+			    tag++) {
+				siop_cmd = siop_lun->siop_tag[tag].active;
+				if (siop_cmd == NULL)
+					continue;
+				printf("cmd %p (target %d:%d) in reset list\n",
+				    siop_cmd, target, lun);
+				TAILQ_INSERT_TAIL(&reset_list, siop_cmd, next);
+				siop_lun->siop_tag[tag].active = NULL;
+			}
+		}
+		sc->targets[target]->status = TARST_ASYNC;
+		sc->targets[target]->flags &= ~TARF_ISWIDE;
+	}
+	/* Next commands from the urgent list */
+	for (siop_cmd = TAILQ_FIRST(&sc->urgent_list); siop_cmd != NULL;
+	    siop_cmd = next_siop_cmd) {
+		next_siop_cmd = TAILQ_NEXT(siop_cmd, next);
+		siop_cmd->flags &= ~CMDFL_TAG;
+		printf("cmd %p (target %d:%d) in reset list (wait)\n",
+		    siop_cmd, siop_cmd->xs->sc_link->target,
+		    siop_cmd->xs->sc_link->lun);
+		TAILQ_REMOVE(&sc->urgent_list, siop_cmd, next);
+		TAILQ_INSERT_TAIL(&reset_list, siop_cmd, next);
+	}
+	/* Then command waiting in the input list */
+	for (siop_cmd = TAILQ_FIRST(&sc->ready_list); siop_cmd != NULL;
+	    siop_cmd = next_siop_cmd) {
+		next_siop_cmd = TAILQ_NEXT(siop_cmd, next);
+		siop_cmd->flags &= ~CMDFL_TAG;
+		printf("cmd %p (target %d:%d) in reset list (wait)\n",
+		    siop_cmd, siop_cmd->xs->sc_link->target,
+		    siop_cmd->xs->sc_link->lun);
+		TAILQ_REMOVE(&sc->ready_list, siop_cmd, next);
+		TAILQ_INSERT_TAIL(&reset_list, siop_cmd, next);
+	}
+
+	for (siop_cmd = TAILQ_FIRST(&reset_list); siop_cmd != NULL;
+	    siop_cmd = next_siop_cmd) {
+		next_siop_cmd = TAILQ_NEXT(siop_cmd, next);
+		siop_cmd->xs->error = (siop_cmd->flags & CMDFL_TIMEOUT) ?
+		    XS_TIMEOUT : XS_RESET;
+		siop_cmd->siop_tables.status = htole32(SCSI_SIOP_NOCHECK);
+		printf("cmd %p (status %d) about to be processed\n", siop_cmd,
+		    siop_cmd->status);
+		if (siop_cmd->status == CMDST_SENSE ||
+		    siop_cmd->status == CMDST_SENSE_ACTIVE) 
+			siop_cmd->status = CMDST_SENSE_DONE;
+		else
+			siop_cmd->status = CMDST_DONE;
+		TAILQ_REMOVE(&reset_list, siop_cmd, next);
+		siop_scsicmd_end(siop_cmd);
+		TAILQ_INSERT_TAIL(&sc->free_list, siop_cmd, next);
+	}
+}
+
+int
+siop_scsicmd(xs)
+	struct scsi_xfer *xs;
+{
+	struct siop_softc *sc = (struct siop_softc *)xs->sc_link->adapter_softc;
+	struct siop_cmd *siop_cmd;
+	int s, error, i;
+	const int target = xs->sc_link->target;
+	const int lun = xs->sc_link->lun;
+
+	s = splbio();
+#ifdef SIOP_DEBUG_SCHED
+	printf("starting cmd for %d:%d\n", target, lun);
+#endif
+	siop_cmd = TAILQ_FIRST(&sc->free_list);
+	if (siop_cmd) {
+		TAILQ_REMOVE(&sc->free_list, siop_cmd, next);
+	} else {
+		if (siop_morecbd(sc) == 0) {
+			siop_cmd = TAILQ_FIRST(&sc->free_list);
+#ifdef DIAGNOSTIC
+			if (siop_cmd == NULL)
+				panic("siop_morecbd succeed and does nothing");
+#endif
+			TAILQ_REMOVE(&sc->free_list, siop_cmd, next);
+		}
+	}
+	if (siop_cmd == NULL) {
+		xs->error = XS_DRIVER_STUFFUP;
+		splx(s);
+		return(TRY_AGAIN_LATER);
+	}
+
+	/* Always reset xs->stimeout, lest we timeout_del() with trash */
+	timeout_set(&xs->stimeout, siop_timeout, siop_cmd);
+
+#ifdef DIAGNOSTIC
+	if (siop_cmd->status != CMDST_FREE)
+		panic("siop_scsicmd: new cmd not free");
+#endif
+	if (sc->targets[target] == NULL) {
+#ifdef SIOP_DEBUG
+		printf("%s: alloc siop_target for target %d\n",
+			sc->sc_dev.dv_xname, target);
+#endif
+		sc->targets[target] =
+		    malloc(sizeof(struct siop_target), M_DEVBUF, M_NOWAIT);
+		if (sc->targets[target] == NULL) {
+			printf("%s: can't malloc memory for target %d\n",
+			    sc->sc_dev.dv_xname, target);
+			xs->error = XS_DRIVER_STUFFUP;
+			splx(s);
+			return(TRY_AGAIN_LATER);
+		}
+		sc->targets[target]->status = TARST_PROBING;
+		sc->targets[target]->flags = 0;
+		sc->targets[target]->id = sc->clock_div << 24; /* scntl3 */
+		sc->targets[target]->id |=  target << 16; /* id */
+		/* sc->targets[target]->id |= 0x0 << 8; scxfer is 0 */
+
+		/* get a lun switch script */
+		sc->targets[target]->lunsw = siop_get_lunsw(sc);
+		if (sc->targets[target]->lunsw == NULL) {
+			printf("%s: can't alloc lunsw for target %d\n",
+			    sc->sc_dev.dv_xname, target);
+			xs->error = XS_DRIVER_STUFFUP;
+			splx(s);
+			return(TRY_AGAIN_LATER);
+		}
+		for (i=0; i < 8; i++)
+			sc->targets[target]->siop_lun[i] = NULL;
+		siop_add_reselsw(sc, target);
+	}
+	if (sc->targets[target]->siop_lun[lun] == NULL) {
+		sc->targets[target]->siop_lun[lun] =
+		    malloc(sizeof(struct siop_lun), M_DEVBUF, M_NOWAIT);
+		if (sc->targets[target]->siop_lun[lun] == NULL) {
+			printf("%s: can't alloc siop_lun for target %d "
+			    "lun %d\n", sc->sc_dev.dv_xname, target, lun);
+			xs->error = XS_DRIVER_STUFFUP;
+			splx(s);
+			return(TRY_AGAIN_LATER);
+		}
+		memset(sc->targets[target]->siop_lun[lun], 0,
+		    sizeof(struct siop_lun));
+	}
+	siop_cmd->siop_target = sc->targets[target];
+	siop_cmd->xs = xs;
+	siop_cmd->flags = 0;
+	siop_cmd->status = CMDST_READY;
+
+	/* load the DMA maps */
+	error = bus_dmamap_load(sc->sc_dmat, siop_cmd->dmamap_cmd,
+	    xs->cmd, xs->cmdlen, NULL, BUS_DMA_NOWAIT);
+	if (error) {
+		printf("%s: unable to load cmd DMA map: %d",
+		    sc->sc_dev.dv_xname, error);
+		xs->error = XS_DRIVER_STUFFUP;
+		splx(s);
+		return(TRY_AGAIN_LATER);
+	}
+	if (xs->flags & (SCSI_DATA_IN | SCSI_DATA_OUT)) {
+		error = bus_dmamap_load(sc->sc_dmat, siop_cmd->dmamap_data,
+		    xs->data, xs->datalen, NULL, BUS_DMA_NOWAIT);
+		if (error) {
+			printf("%s: unable to load cmd DMA map: %d",
+			    sc->sc_dev.dv_xname, error);
+			xs->error = XS_DRIVER_STUFFUP;
+			bus_dmamap_unload(sc->sc_dmat, siop_cmd->dmamap_cmd);
+			splx(s);
+			return(TRY_AGAIN_LATER);
+		}
+		bus_dmamap_sync(sc->sc_dmat, siop_cmd->dmamap_data,
+		    (xs->flags & SCSI_DATA_IN) ?
+		    BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
+	}
+	bus_dmamap_sync(sc->sc_dmat, siop_cmd->dmamap_cmd,
+	    BUS_DMASYNC_PREWRITE);
+
+	siop_setuptables(siop_cmd);
+
+	TAILQ_INSERT_TAIL(&sc->ready_list, siop_cmd, next);
+
+	siop_start(sc);
+	if (xs->flags & SCSI_POLL) {
+		/* poll for command completion */
+		while ((xs->flags & ITSDONE) == 0) {
+			delay(1000);
+			siop_intr(sc);
+		}
+		splx(s);
+		return (COMPLETE);
+	}
+	splx(s);
+	return (SUCCESSFULLY_QUEUED);
+}
+
+void
+siop_start(sc)
+	struct siop_softc *sc;
+{
+	struct siop_cmd *siop_cmd, *next_siop_cmd;
+	struct siop_lun *siop_lun;
+	u_int32_t dsa;
+	int timeout;
+	int target, lun, tag, slot;
+	int newcmd = 0; 
+	int doingready = 0;
+
+	/*
+	 * first make sure to read valid data
+	 */
+	siop_script_sync(sc, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
+
+	/*
+	 * The queue management here is a bit tricky: the script always looks
+	 * at the slot from first to last, so if we always use the first 
+	 * free slot commands can stay at the tail of the queue ~forever.
+	 * The algorithm used here is to restart from the head when we know
+	 * that the queue is empty, and only add commands after the last one.
+	 * When we're at the end of the queue wait for the script to clear it.
+	 * The best thing to do here would be to implement a circular queue,
+	 * but using only 53c720 features this can be "interesting".
+	 * A mid-way solution could be to implement 2 queues and swap orders.
+	 */
+	slot = sc->sc_currschedslot;
+	/*
+	 * If the instruction is 0x80000000 (JUMP foo, IF FALSE) the slot is
+	 * free. As this is the last used slot, all previous slots are free,
+	 * we can restart from 1.
+	 * slot 0 is reserved for request sense commands.
+	 */
+	if (siop_script_read(sc, (Ent_script_sched_slot0 / 4) + slot * 2) ==
+	    0x80000000) {
+		slot = sc->sc_currschedslot = 1;
+	} else {
+		slot++;
+	}
+	/* first handle commands from the urgent list */
+	siop_cmd = TAILQ_FIRST(&sc->urgent_list);
+again:
+	for (; siop_cmd != NULL; siop_cmd = next_siop_cmd) {
+		next_siop_cmd = TAILQ_NEXT(siop_cmd, next);
+#ifdef DIAGNOSTIC
+		if (siop_cmd->status != CMDST_READY &&
+		    siop_cmd->status != CMDST_SENSE)
+			panic("siop: non-ready cmd in ready list");
+#endif	
+		target = siop_cmd->xs->sc_link->target;
+		lun = siop_cmd->xs->sc_link->lun;
+		siop_lun = sc->targets[target]->siop_lun[lun];
+		/* if non-tagged command active, wait */
+		if (siop_lun->siop_tag[0].active != NULL)
+			continue;
+		/*
+		 * if we're in a queue full condition don't start a new
+		 * command, unless it's a request sense
+		 */
+		if ((siop_lun->lun_flags & SIOP_LUNF_FULL) &&
+		    siop_cmd->status == CMDST_READY)
+			continue;
+		/* find a free tag if needed */
+		if (siop_cmd->flags & CMDFL_TAG) {
+			for (tag = 1; tag < SIOP_NTAG; tag++) {
+				if (siop_lun->siop_tag[tag].active == NULL)
+					break;
+			}
+			if (tag == SIOP_NTAG) /* no free tag */
+				continue;
+		} else {
+			tag = 0;
+		}
+		siop_cmd->tag = tag;
+		/*
+		 * find a free scheduler slot and load it. If it's a request
+		 * sense we need to use slot 0.
+		 */
+		if (siop_cmd->status != CMDST_SENSE) {
+			for (; slot < SIOP_NSLOTS; slot++) {
+				/*
+				 * If cmd if 0x80000000 the slot is free
+				 */
+				if (siop_script_read(sc,
+				    (Ent_script_sched_slot0 / 4) + slot * 2) ==
+				    0x80000000)
+					break;
+			}
+			/* no more free slot, no need to continue */
+			if (slot == SIOP_NSLOTS) {
+				goto end;
+			}
+		} else {
+			slot = 0;
+			if (siop_script_read(sc, Ent_script_sched_slot0 / 4)
+			    != 0x80000000) 
+				goto end;
+		}
+
+#ifdef SIOP_DEBUG_SCHED
+		printf("using slot %d for DSA 0x%lx\n", slot,
+		    (u_long)siop_cmd->dsa);
+#endif
+		/* Ok, we can add the tag message */
+		if (tag > 0) {
+#ifdef DIAGNOSTIC
+			int msgcount =
+			    letoh32(siop_cmd->siop_tables.t_msgout.count);
+			if (msgcount != 1)
+				printf("%s:%d:%d: tag %d with msgcount %d\n",
+				    sc->sc_dev.dv_xname, target, lun, tag,
+				    msgcount);
+#endif
+			if (siop_cmd->xs->bp != NULL &&
+			    (siop_cmd->xs->bp->b_flags & B_ASYNC))
+				siop_cmd->siop_tables.msg_out[1] =
+				    MSG_SIMPLE_Q_TAG;
+			else
+				siop_cmd->siop_tables.msg_out[1] =
+				    MSG_ORDERED_Q_TAG;
+			siop_cmd->siop_tables.msg_out[2] = tag;
+			siop_cmd->siop_tables.t_msgout.count = htole32(3);
+		}
+		/* note that we started a new command */
+		newcmd = 1;
+		/* mark command as active */
+		if (siop_cmd->status == CMDST_READY) {
+			siop_cmd->status = CMDST_ACTIVE;
+		} else if (siop_cmd->status == CMDST_SENSE) {
+			siop_cmd->status = CMDST_SENSE_ACTIVE;
+		} else
+			panic("siop_start: bad status");
+		if (doingready)
+			TAILQ_REMOVE(&sc->ready_list, siop_cmd, next);
+		else
+			TAILQ_REMOVE(&sc->urgent_list, siop_cmd, next);
+		siop_lun->siop_tag[tag].active = siop_cmd;
+		/* patch scripts with DSA addr */
+		dsa = siop_cmd->dsa;
+		/* first reselect switch, if we have an entry */
+		if (siop_lun->siop_tag[tag].reseloff > 0)
+			siop_script_write(sc,
+			    siop_lun->siop_tag[tag].reseloff + 1,
+			    dsa + sizeof(struct siop_xfer_common) +
+			    Ent_ldsa_reload_dsa);
+		/* CMD script: MOVE MEMORY addr */
+		siop_cmd->siop_xfer->resel[E_ldsa_abs_slot_Used[0]] = 
+		   htole32(sc->sc_scriptaddr + Ent_script_sched_slot0 +
+		   slot * 8);
+		siop_table_sync(siop_cmd, BUS_DMASYNC_PREWRITE);
+		/* scheduler slot: JUMP ldsa_select */
+		siop_script_write(sc,
+		    (Ent_script_sched_slot0 / 4) + slot * 2 + 1,
+		    dsa + sizeof(struct siop_xfer_common) + Ent_ldsa_select);
+		/* handle timeout */
+		if (siop_cmd->status == CMDST_ACTIVE) {
+			if ((siop_cmd->xs->flags & SCSI_POLL) == 0) {
+				/* start exire timer */
+				timeout = (u_int64_t) siop_cmd->xs->timeout *
+				    (u_int64_t)hz / 1000;
+				if (timeout == 0)
+					timeout = 1;
+				timeout_add(&siop_cmd->xs->stimeout, timeout);
+			}
+		}
+		/*
+		 * Change JUMP cmd so that this slot will be handled
+		 */
+		siop_script_write(sc, (Ent_script_sched_slot0 / 4) + slot * 2,
+		    0x80080000);
+		/* if we're using the request sense slot, stop here */
+		if (slot == 0)
+			goto end;
+		sc->sc_currschedslot = slot;
+		slot++;
+	}
+	if (doingready == 0) {
+		/* now process ready list */
+		doingready = 1;
+		siop_cmd = TAILQ_FIRST(&sc->ready_list);
+		goto again;
+	}
+
+end:
+	/* if nothing changed no need to flush cache and wakeup script */
+	if (newcmd == 0)
+		return;
+	/* make sure SCRIPT processor will read valid data */
+	siop_script_sync(sc,BUS_DMASYNC_PREREAD |  BUS_DMASYNC_PREWRITE);
+	/* Signal script it has some work to do */
+	bus_space_write_1(sc->sc_rt, sc->sc_rh, SIOP_ISTAT, ISTAT_SIGP);
+	/* and wait for IRQ */
+	return;
+}
+
+void
+siop_timeout(v)
+	void *v;
+{
+	struct siop_cmd *siop_cmd = v;
+	struct siop_softc *sc = siop_cmd->siop_sc;
+	int s;
+
+	sc_print_addr(siop_cmd->xs->sc_link);
+	printf("command timeout\n");
+
+	s = splbio();
+	/* reset the scsi bus */
+	siop_resetbus(sc);
+
+	/* deactivate callout */
+	timeout_del(&siop_cmd->xs->stimeout);
+	/* mark command as being timed out; siop_intr will handle it */
+	/*
+	 * mark command has being timed out and just return;
+	 * the bus reset will generate an interrupt,
+	 * it will be handled in siop_intr()
+	 */
+	siop_cmd->flags |= CMDFL_TIMEOUT;
+	splx(s);
+	return;
+
+}
+
+void
+siop_dump_script(sc)
+	struct siop_softc *sc;
+{
+	int i;
+	for (i = 0; i < PAGE_SIZE / 4; i += 2) {
+		printf("0x%04x: 0x%08x 0x%08x", i * 4,
+		    letoh32(sc->sc_script[i]), letoh32(sc->sc_script[i+1]));
+		if ((letoh32(sc->sc_script[i]) & 0xe0000000) == 0xc0000000) {
+			i++;
+			printf(" 0x%08x", letoh32(sc->sc_script[i+1]));
+		}
+		printf("\n");
+	}
+}
+
+int
+siop_morecbd(sc)
+	struct siop_softc *sc;
+{
+	int error, i, j;
+	bus_dma_segment_t seg;
+	int rseg;
+	struct siop_cbd *newcbd;
+	bus_addr_t dsa;
+	u_int32_t *scr;
+
+	/* allocate a new list head */
+	newcbd = malloc(sizeof(struct siop_cbd), M_DEVBUF, M_NOWAIT);
+	if (newcbd == NULL) {
+		printf("%s: can't allocate memory for command descriptors "
+		    "head\n", sc->sc_dev.dv_xname);
+		return ENOMEM;
+	}
+	memset(newcbd, 0, sizeof(struct siop_cbd));
+
+	/* allocate cmd list */
+	newcbd->cmds =
+	    malloc(sizeof(struct siop_cmd) * SIOP_NCMDPB, M_DEVBUF, M_NOWAIT);
+	if (newcbd->cmds == NULL) {
+		printf("%s: can't allocate memory for command descriptors\n",
+		    sc->sc_dev.dv_xname);
+		error = ENOMEM;
+		goto bad3;
+	}
+	memset(newcbd->cmds, 0, sizeof(struct siop_cmd) * SIOP_NCMDPB);
+	error = bus_dmamem_alloc(sc->sc_dmat, PAGE_SIZE, PAGE_SIZE, 0, &seg,
+	    1, &rseg, BUS_DMA_NOWAIT);
+	if (error) {
+		printf("%s: unable to allocate cbd DMA memory, error = %d\n",
+		    sc->sc_dev.dv_xname, error);
+		goto bad2;
+	}
+	error = bus_dmamem_map(sc->sc_dmat, &seg, rseg, PAGE_SIZE,
+	    (caddr_t *)&newcbd->xfers, BUS_DMA_NOWAIT|BUS_DMA_COHERENT);
+	if (error) {
+		printf("%s: unable to map cbd DMA memory, error = %d\n",
+		    sc->sc_dev.dv_xname, error);
+		goto bad2;
+	}
+	error = bus_dmamap_create(sc->sc_dmat, PAGE_SIZE, 1, PAGE_SIZE, 0,
+	    BUS_DMA_NOWAIT, &newcbd->xferdma);
+	if (error) {
+		printf("%s: unable to create cbd DMA map, error = %d\n",
+		    sc->sc_dev.dv_xname, error);
+		goto bad1;
+	}
+	error = bus_dmamap_load(sc->sc_dmat, newcbd->xferdma, newcbd->xfers,
+	    PAGE_SIZE, NULL, BUS_DMA_NOWAIT);
+	if (error) {
+		printf("%s: unable to load cbd DMA map, error = %d\n",
+		    sc->sc_dev.dv_xname, error);
+		goto bad0;
+	}
+#ifdef DEBUG
+	printf("%s: alloc newcdb at PHY addr 0x%lx\n", sc->sc_dev.dv_xname,
+	    (unsigned long)newcbd->xferdma->dm_segs[0].ds_addr);
+#endif
+	
+	for (i = 0; i < SIOP_NCMDPB; i++) {
+		error = bus_dmamap_create(sc->sc_dmat, MAXPHYS, SIOP_NSG,
+		    MAXPHYS, 0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
+		    &newcbd->cmds[i].dmamap_data);
+		if (error) {
+			printf("%s: unable to create data DMA map for cbd: "
+			    "error %d\n",
+			    sc->sc_dev.dv_xname, error);
+			goto bad0;
+		}
+		error = bus_dmamap_create(sc->sc_dmat,
+		    sizeof(struct scsi_generic), 1,
+		    sizeof(struct scsi_generic), 0,
+		    BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
+		    &newcbd->cmds[i].dmamap_cmd);
+		if (error) {
+			printf("%s: unable to create cmd DMA map for cbd %d\n",
+			    sc->sc_dev.dv_xname, error);
+			goto bad0;
+		}
+		newcbd->cmds[i].siop_sc = sc;
+		newcbd->cmds[i].siop_cbdp = newcbd;
+		newcbd->cmds[i].siop_xfer = &newcbd->xfers[i];
+		memset(newcbd->cmds[i].siop_xfer, 0,
+		    sizeof(struct siop_xfer));
+		newcbd->cmds[i].dsa = newcbd->xferdma->dm_segs[0].ds_addr +
+		    i * sizeof(struct siop_xfer);
+		dsa = newcbd->cmds[i].dsa;
+		newcbd->cmds[i].status = CMDST_FREE;
+		newcbd->cmds[i].siop_tables.t_msgout.count= htole32(1);
+		newcbd->cmds[i].siop_tables.t_msgout.addr = htole32(dsa);
+		newcbd->cmds[i].siop_tables.t_msgin.count= htole32(1);
+		newcbd->cmds[i].siop_tables.t_msgin.addr = htole32(dsa + 8);
+		newcbd->cmds[i].siop_tables.t_extmsgin.count= htole32(2);
+		newcbd->cmds[i].siop_tables.t_extmsgin.addr = htole32(dsa + 9);
+		newcbd->cmds[i].siop_tables.t_extmsgdata.addr =
+		    htole32(dsa + 11);
+		newcbd->cmds[i].siop_tables.t_status.count= htole32(1);
+		newcbd->cmds[i].siop_tables.t_status.addr = htole32(dsa + 16);
+
+		/* The select/reselect script */
+		scr = &newcbd->cmds[i].siop_xfer->resel[0];
+		for (j = 0; j < sizeof(load_dsa) / sizeof(load_dsa[0]); j++)
+			scr[j] = htole32(load_dsa[j]);
+		/*
+		 * 0x78000000 is a 'move data8 to reg'. data8 is the second
+		 * octet, reg offset is the third.
+		 */
+		scr[Ent_rdsa0 / 4] =
+		    htole32(0x78100000 | ((dsa & 0x000000ff) <<  8));
+		scr[Ent_rdsa1 / 4] =
+		    htole32(0x78110000 | ( dsa & 0x0000ff00       ));
+		scr[Ent_rdsa2 / 4] =
+		    htole32(0x78120000 | ((dsa & 0x00ff0000) >>  8));
+		scr[Ent_rdsa3 / 4] =
+		    htole32(0x78130000 | ((dsa & 0xff000000) >> 16));
+		scr[E_ldsa_abs_reselected_Used[0]] =
+		    htole32(sc->sc_scriptaddr + Ent_reselected);
+		scr[E_ldsa_abs_reselect_Used[0]] =
+		    htole32(sc->sc_scriptaddr + Ent_reselect);
+		scr[E_ldsa_abs_selected_Used[0]] =
+		    htole32(sc->sc_scriptaddr + Ent_selected);
+		scr[E_ldsa_abs_data_Used[0]] =
+		    htole32(dsa + sizeof(struct siop_xfer_common) +
+		    Ent_ldsa_data);
+		/* JUMP foo, IF FALSE - used by MOVE MEMORY to clear the slot */
+		scr[Ent_ldsa_data / 4] = htole32(0x80000000);
+		TAILQ_INSERT_TAIL(&sc->free_list, &newcbd->cmds[i], next);
+#ifdef SIOP_DEBUG
+		printf("tables[%d]: in=0x%x out=0x%x status=0x%x\n", i,
+		    letoh32(newcbd->cmds[i].siop_tables.t_msgin.addr),
+		    letoh32(newcbd->cmds[i].siop_tables.t_msgout.addr),
+		    letoh32(newcbd->cmds[i].siop_tables.t_status.addr));
+#endif
+	}
+	TAILQ_INSERT_TAIL(&sc->cmds, newcbd, next);
+	return 0;
+bad0:
+	bus_dmamap_destroy(sc->sc_dmat, newcbd->xferdma);
+bad1:
+	bus_dmamem_free(sc->sc_dmat, &seg, rseg);
+bad2:
+	free(newcbd->cmds, M_DEVBUF);
+bad3:
+	free(newcbd, M_DEVBUF);
+	return error;
+}
+
+struct siop_lunsw *
+siop_get_lunsw(sc)
+	struct siop_softc *sc;
+{
+	struct siop_lunsw *lunsw;
+	int i;
+
+	if (sc->script_free_lo + (sizeof(lun_switch) / sizeof(lun_switch[0])) >=
+	    sc->script_free_hi)
+		return NULL;
+	lunsw = TAILQ_FIRST(&sc->lunsw_list);
+	if (lunsw != NULL) {
+#ifdef SIOP_DEBUG
+		printf("siop_get_lunsw got lunsw at offset %d\n",
+		    lunsw->lunsw_off);
+#endif
+		TAILQ_REMOVE(&sc->lunsw_list, lunsw, next);
+		return lunsw;
+	}
+	lunsw = malloc(sizeof(struct siop_lunsw), M_DEVBUF, M_NOWAIT);
+	if (lunsw == NULL)
+		return NULL;
+	memset(lunsw, 0, sizeof(struct siop_lunsw));
+#ifdef SIOP_DEBUG
+	printf("allocating lunsw at offset %d\n", sc->script_free_lo);
+#endif
+	if (sc->features & SF_CHIP_RAM) {
+		bus_space_write_region_4(sc->sc_ramt, sc->sc_ramh,
+		    sc->script_free_lo * 4, lun_switch,
+		    sizeof(lun_switch) / sizeof(lun_switch[0]));
+		bus_space_write_4(sc->sc_ramt, sc->sc_ramh,
+		    (sc->script_free_lo + E_abs_lunsw_return_Used[0]) * 4,
+		    sc->sc_scriptaddr + Ent_lunsw_return);
+	} else {
+		for (i = 0; i < sizeof(lun_switch) / sizeof(lun_switch[0]);
+		    i++)
+			sc->sc_script[sc->script_free_lo + i] =
+			    htole32(lun_switch[i]);
+		sc->sc_script[sc->script_free_lo + E_abs_lunsw_return_Used[0]] = 
+		    htole32(sc->sc_scriptaddr + Ent_lunsw_return);
+	}
+	lunsw->lunsw_off = sc->script_free_lo;
+	lunsw->lunsw_size = sizeof(lun_switch) / sizeof(lun_switch[0]);
+	sc->script_free_lo += lunsw->lunsw_size;
+	if (sc->script_free_lo > 1024)
+		printf("%s: script_free_lo (%d) > 1024\n", sc->sc_dev.dv_xname,
+		    sc->script_free_lo);
+	siop_script_sync(sc, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+	return lunsw;
+}
+
+void
+siop_add_reselsw(sc, target)
+	struct siop_softc *sc;
+	int target;
+{
+	int i;
+	struct siop_lun *siop_lun;
+	/*
+	 * add an entry to resel switch
+	 */
+	siop_script_sync(sc, BUS_DMASYNC_POSTWRITE);
+	for (i = 0; i < 15; i++) {
+		sc->targets[target]->reseloff = Ent_resel_targ0 / 4 + i * 2;
+		if ((siop_script_read(sc, sc->targets[target]->reseloff) & 0xff)
+		    == 0xff) { /* it's free */
+#ifdef SIOP_DEBUG
+			printf("siop: target %d slot %d offset %d\n",
+			    target, i, sc->targets[target]->reseloff);
+#endif
+			/* JUMP abs_foo, IF target | 0x80; */
+			siop_script_write(sc, sc->targets[target]->reseloff,
+			    0x800c0080 | target);
+			siop_script_write(sc, sc->targets[target]->reseloff + 1,
+			    sc->sc_scriptaddr +
+			    sc->targets[target]->lunsw->lunsw_off * 4 +
+			    Ent_lun_switch_entry);
+			break;
+		}
+	}
+	if (i == 15) /* no free slot, shouldn't happen */
+		panic("siop: resel switch full");
+
+	sc->sc_ntargets++;
+	for (i = 0; i < 8; i++) {
+		siop_lun = sc->targets[target]->siop_lun[i];
+		if (siop_lun == NULL)
+			continue;
+		if (siop_lun->reseloff > 0) {
+			siop_lun->reseloff = 0;
+			siop_add_dev(sc, target, i);
+		}
+	}
+	siop_update_scntl3(sc, sc->targets[target]);
+	siop_script_sync(sc, BUS_DMASYNC_PREWRITE);
+}
+
+void
+siop_update_scntl3(sc, siop_target)
+	struct siop_softc *sc;
+	struct siop_target *siop_target;
+{
+	/* MOVE target->id >> 24 TO SCNTL3 */
+	siop_script_write(sc,
+	    siop_target->lunsw->lunsw_off + (Ent_restore_scntl3 / 4),
+	    0x78030000 | ((siop_target->id >> 16) & 0x0000ff00));
+	/* MOVE target->id >> 8 TO SXFER */
+	siop_script_write(sc,
+	    siop_target->lunsw->lunsw_off + (Ent_restore_scntl3 / 4) + 2,
+	    0x78050000 | (siop_target->id & 0x0000ff00));
+	siop_script_sync(sc, BUS_DMASYNC_PREWRITE);
+}
+
+void
+siop_add_dev(sc, target, lun)
+	struct siop_softc *sc;
+	int target;
+	int lun;
+{
+	struct siop_lunsw *lunsw;
+	struct siop_lun *siop_lun = sc->targets[target]->siop_lun[lun];
+	int i, ntargets;
+
+	if (siop_lun->reseloff > 0)
+		return;
+	lunsw = sc->targets[target]->lunsw;
+	if ((lunsw->lunsw_off + lunsw->lunsw_size) < sc->script_free_lo) {
+		/*
+		 * can't extend this slot. Probably not worth trying to deal
+		 * with this case
+		 */
+#ifdef DEBUG
+		printf("%s:%d:%d: can't allocate a lun sw slot\n",
+		    sc->sc_dev.dv_xname, target, lun);
+#endif
+		return;
+	}
+	/* count how many free targets we still have to probe */
+	ntargets =  (sc->sc_link.adapter_buswidth - 1) - 1 - sc->sc_ntargets;
+
+	/*
+	 * we need 8 bytes for the lun sw additionnal entry, and
+	 * eventually sizeof(tag_switch) for the tag switch entry.
+	 * Keep enouth free space for the free targets that could be
+	 * probed later.
+	 */
+	if (sc->script_free_lo + 2 +
+	    (ntargets * sizeof(lun_switch) / sizeof(lun_switch[0])) >=
+	    ((sc->targets[target]->flags & TARF_TAG) ?
+	    sc->script_free_hi - (sizeof(tag_switch) / sizeof(tag_switch[0])) :
+	    sc->script_free_hi)) {
+		/*
+		 * not enouth space, probably not worth dealing with it.
+		 * We can hold 13 tagged-queuing capable devices in the 4k RAM.
+		 */
+#ifdef DEBUG
+		printf("%s:%d:%d: not enouth memory for a lun sw slot\n",
+		    sc->sc_dev.dv_xname, target, lun);
+#endif
+		return;
+	}
+#ifdef SIOP_DEBUG
+	printf("%s:%d:%d: allocate lun sw entry\n",
+	    sc->sc_dev.dv_xname, target, lun);
+#endif
+	/* INT int_resellun */
+	siop_script_write(sc, sc->script_free_lo, 0x98080000);
+	siop_script_write(sc, sc->script_free_lo + 1, A_int_resellun);
+	/* Now the slot entry: JUMP abs_foo, IF lun */
+	siop_script_write(sc, sc->script_free_lo - 2,
+	    0x800c0000 | lun);
+	siop_script_write(sc, sc->script_free_lo - 1, 0);
+	siop_lun->reseloff = sc->script_free_lo - 2;
+	lunsw->lunsw_size += 2;
+	sc->script_free_lo += 2;
+	if (sc->targets[target]->flags & TARF_TAG) {
+		/* we need a tag switch */
+		sc->script_free_hi -=
+		    sizeof(tag_switch) / sizeof(tag_switch[0]);
+		if (sc->features & SF_CHIP_RAM) {
+			bus_space_write_region_4(sc->sc_ramt, sc->sc_ramh,
+			    sc->script_free_hi * 4, tag_switch,
+			    sizeof(tag_switch) / sizeof(tag_switch[0]));
+		} else {
+			for(i = 0;
+			    i < sizeof(tag_switch) / sizeof(tag_switch[0]);
+			    i++) {
+				sc->sc_script[sc->script_free_hi + i] = 
+				    htole32(tag_switch[i]);
+			}
+		}
+		siop_script_write(sc, 
+		    siop_lun->reseloff + 1,
+		    sc->sc_scriptaddr + sc->script_free_hi * 4 +
+		    Ent_tag_switch_entry);
+
+		for (i = 0; i < SIOP_NTAG; i++) {
+			siop_lun->siop_tag[i].reseloff =
+			    sc->script_free_hi + (Ent_resel_tag0 / 4) + i * 2;
+		}
+	} else {
+		/* non-tag case; just work with the lun switch */
+		siop_lun->siop_tag[0].reseloff = 
+		    sc->targets[target]->siop_lun[lun]->reseloff;
+	}
+	siop_script_sync(sc, BUS_DMASYNC_PREWRITE);
+}
+
+void
+siop_del_dev(sc, target, lun)
+	struct siop_softc *sc;
+	int target;
+	int lun;
+{
+	int i;
+#ifdef SIOP_DEBUG
+		printf("%s:%d:%d: free lun sw entry\n",
+		    sc->sc_dev.dv_xname, target, lun);
+#endif
+	if (sc->targets[target] == NULL)
+		return;
+	free(sc->targets[target]->siop_lun[lun], M_DEVBUF);
+	sc->targets[target]->siop_lun[lun] = NULL;
+	/* XXX compact sw entry too ? */
+	/* check if we can free the whole target */
+	for (i = 0; i < 8; i++) {
+		if (sc->targets[target]->siop_lun[i] != NULL)
+			return;
+	}
+#ifdef SIOP_DEBUG
+	printf("%s: free siop_target for target %d lun %d lunsw offset %d\n",
+	    sc->sc_dev.dv_xname, target, lun,
+	    sc->targets[target]->lunsw->lunsw_off);
+#endif
+	/*
+	 * nothing here, free the target struct and resel
+	 * switch entry
+	 */
+	siop_script_write(sc, sc->targets[target]->reseloff, 0x800c00ff);
+	siop_script_sync(sc, BUS_DMASYNC_PREWRITE);
+	TAILQ_INSERT_TAIL(&sc->lunsw_list, sc->targets[target]->lunsw, next);
+	free(sc->targets[target], M_DEVBUF);
+	sc->targets[target] = NULL;
+	sc->sc_ntargets--;
+}
+
+#ifdef SIOP_STATS
+void
+siop_printstats()
+{
+	printf("siop_stat_intr %d\n", siop_stat_intr);
+	printf("siop_stat_intr_shortxfer %d\n", siop_stat_intr_shortxfer);
+	printf("siop_stat_intr_xferdisc %d\n", siop_stat_intr_xferdisc);
+	printf("siop_stat_intr_sdp %d\n", siop_stat_intr_sdp);
+	printf("siop_stat_intr_done %d\n", siop_stat_intr_done);
+	printf("siop_stat_intr_lunresel %d\n", siop_stat_intr_lunresel);
+	printf("siop_stat_intr_qfull %d\n", siop_stat_intr_qfull);
+}
+#endif