text: /*	$OpenBSD: siop.c,v 1.71 2015/09/09 18:24:26 deraadt Exp $ */
  /*	$NetBSD: siop.c,v 1.79 2005/11/18 23:10:32 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.
   *
   * 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/kernel.h>
  #include <sys/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_common.h>
  #include <dev/ic/siopvar.h>
  
  #ifndef SIOP_DEBUG
  #undef SIOP_DEBUG
  #undef SIOP_DEBUG_DR
  #undef SIOP_DEBUG_INTR
  #undef SIOP_DEBUG_SCHED
  #undef DUMP_SCRIPT
  #else
  #define SIOP_DEBUG_DR
  #define SIOP_DEBUG_INTR
  #define SIOP_DEBUG_SCHED
  #define DUMP_SCRIPT
  #endif
  
  
  #undef 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_table_sync(struct siop_cmd *, int);
  void	siop_script_sync(struct siop_softc *, int);
  u_int32_t siop_script_read(struct siop_softc *, u_int);
  void	siop_script_write(struct siop_softc *, u_int, u_int32_t);
  void	siop_reset(struct siop_softc *);
  void	siop_handle_reset(struct siop_softc *);
  int	siop_handle_qtag_reject(struct siop_cmd *);
  void	siop_scsicmd_end(struct siop_cmd *);
  void	siop_start(struct siop_softc *);
  void 	siop_timeout(void *);
  void	siop_scsicmd(struct scsi_xfer *);
  void *	siop_cmd_get(void *);
  void	siop_cmd_put(void *, void *);
  int	siop_scsiprobe(struct scsi_link *);
  void	siop_scsifree(struct scsi_link *);
  #ifdef DUMP_SCRIPT
  void	siop_dump_script(struct siop_softc *);
  #endif
  void	siop_morecbd(struct siop_softc *);
  struct siop_lunsw *siop_get_lunsw(struct siop_softc *);
  void	siop_add_reselsw(struct siop_softc *, int);
  void	siop_update_scntl3(struct siop_softc *, struct siop_common_target *);
  
  struct siop_dmamem *siop_dmamem_alloc(struct siop_softc *, size_t);
  void	siop_dmamem_free(struct siop_softc *, struct siop_dmamem *);
  
  struct cfdriver siop_cd = {
  	NULL, "siop", DV_DULL
  };
  
  struct scsi_adapter siop_adapter = {
  	siop_scsicmd,
  	siop_minphys,
  	siop_scsiprobe,
  	siop_scsifree
  };
  
  #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_saveoffset = 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(void);
  #define INCSTAT(x) x++
  #else
  #define INCSTAT(x)
  #endif
  
  void
  siop_table_sync(siop_cmd, ops)
  	struct siop_cmd *siop_cmd;
  	int ops;
  {
  	struct siop_common_softc *sc  = siop_cmd->cmd_c.siop_sc;
  	bus_addr_t offset;
  
  	offset = siop_cmd->cmd_c.dsa -
  	    SIOP_DMA_DVA(siop_cmd->siop_cbdp->xfers);
  	bus_dmamap_sync(sc->sc_dmat,
  	    SIOP_DMA_MAP(siop_cmd->siop_cbdp->xfers), offset,
  	    sizeof(struct siop_xfer), ops);
  }
  
  void
  siop_script_sync(sc, ops)
  	struct siop_softc *sc;
  	int ops;
  {
  	if ((sc->sc_c.features & SF_CHIP_RAM) == 0)
  		bus_dmamap_sync(sc->sc_c.sc_dmat, sc->sc_c.sc_scriptdma, 0,
  		    PAGE_SIZE, ops);
  }
  
  u_int32_t
  siop_script_read(sc, offset)
  	struct siop_softc *sc;
  	u_int offset;
  {
  	if (sc->sc_c.features & SF_CHIP_RAM) {
  		return bus_space_read_4(sc->sc_c.sc_ramt, sc->sc_c.sc_ramh,
  		    offset * 4);
  	} else {
  		return siop_ctoh32(&sc->sc_c, sc->sc_c.sc_script[offset]);
  	}
  }
  
  void
  siop_script_write(sc, offset, val)
  	struct siop_softc *sc;
  	u_int offset;
  	u_int32_t val;
  {
  	if (sc->sc_c.features & SF_CHIP_RAM) {
  		bus_space_write_4(sc->sc_c.sc_ramt, sc->sc_c.sc_ramh,
  		    offset * 4, val);
  	} else {
  		sc->sc_c.sc_script[offset] = siop_htoc32(&sc->sc_c, val);
  	}
  }
  
  void
  siop_attach(sc)
  	struct siop_softc *sc;
  {
  	struct scsibus_attach_args saa;
  
  	if (siop_common_attach(&sc->sc_c) != 0)
  		return;
  
  	TAILQ_INIT(&sc->free_list);
  	TAILQ_INIT(&sc->ready_list);
  	TAILQ_INIT(&sc->urgent_list);
  	TAILQ_INIT(&sc->cmds);
  	TAILQ_INIT(&sc->lunsw_list);
  	scsi_iopool_init(&sc->iopool, sc, siop_cmd_get, siop_cmd_put);
  	sc->sc_currschedslot = 0;
  	sc->sc_c.sc_link.adapter = &siop_adapter;
  	sc->sc_c.sc_link.openings = SIOP_NTAG;
  	sc->sc_c.sc_link.pool = &sc->iopool;
  
  	/* Start with one page worth of commands */
  	siop_morecbd(sc);
  
  #ifdef SIOP_DEBUG
  	printf("%s: script size = %d, PHY addr=0x%x, VIRT=%p\n",
  	    sc->sc_c.sc_dev.dv_xname, (int)sizeof(siop_script),
  	    (u_int32_t)sc->sc_c.sc_scriptaddr, sc->sc_c.sc_script);
  #endif
  
  	/* Do a bus reset, so that devices fall back to narrow/async */
  	siop_resetbus(&sc->sc_c);
  	/*
  	 * siop_reset() will reset the chip, thus clearing pending interrupts
  	 */
  	siop_reset(sc);
  #ifdef DUMP_SCRIPT
  	siop_dump_script(sc);
  #endif
  
  	bzero(&saa, sizeof(saa));
  	saa.saa_sc_link = &sc->sc_c.sc_link;
  
  	config_found((struct device*)sc, &saa, scsiprint);
  }
  
  void
  siop_reset(sc)
  	struct siop_softc *sc;
  {
  	int i, j;
  	struct siop_lunsw *lunsw;
  
  	siop_common_reset(&sc->sc_c);
  
  	/* copy and patch the script */
  	if (sc->sc_c.features & SF_CHIP_RAM) {
  		bus_space_write_region_4(sc->sc_c.sc_ramt, sc->sc_c.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_c.sc_ramt, sc->sc_c.sc_ramh,
  			    E_abs_msgin_Used[j] * 4,
  			    sc->sc_c.sc_scriptaddr + Ent_msgin_space);
  		}
  		if (sc->sc_c.features & SF_CHIP_LED0) {
  			bus_space_write_region_4(sc->sc_c.sc_ramt,
  			    sc->sc_c.sc_ramh,
  			    Ent_led_on1, siop_led_on,
  			    sizeof(siop_led_on) / sizeof(siop_led_on[0]));
  			bus_space_write_region_4(sc->sc_c.sc_ramt,
  			    sc->sc_c.sc_ramh,
  			    Ent_led_on2, siop_led_on,
  			    sizeof(siop_led_on) / sizeof(siop_led_on[0]));
  			bus_space_write_region_4(sc->sc_c.sc_ramt,
  			    sc->sc_c.sc_ramh,
  			    Ent_led_off, siop_led_off,
  			    sizeof(siop_led_off) / sizeof(siop_led_off[0]));
  		}
  	} else {
  		for (j = 0;
  		    j < (sizeof(siop_script) / sizeof(siop_script[0])); j++) {
  			sc->sc_c.sc_script[j] =
  			    siop_htoc32(&sc->sc_c, siop_script[j]);
  		}
  		for (j = 0; j <
  		    (sizeof(E_abs_msgin_Used) / sizeof(E_abs_msgin_Used[0]));
  		    j++) {
  			sc->sc_c.sc_script[E_abs_msgin_Used[j]] =
  			    siop_htoc32(&sc->sc_c,
  				sc->sc_c.sc_scriptaddr + Ent_msgin_space);
  		}
  		if (sc->sc_c.features & SF_CHIP_LED0) {
  			for (j = 0; j < (sizeof(siop_led_on) /
  			    sizeof(siop_led_on[0])); j++)
  				sc->sc_c.sc_script[
  				    Ent_led_on1 / sizeof(siop_led_on[0]) + j
  				    ] = siop_htoc32(&sc->sc_c, siop_led_on[j]);
  			for (j = 0; j < (sizeof(siop_led_on) /
  			    sizeof(siop_led_on[0])); j++)
  				sc->sc_c.sc_script[
  				    Ent_led_on2 / sizeof(siop_led_on[0]) + j
  				    ] = siop_htoc32(&sc->sc_c, siop_led_on[j]);
  			for (j = 0; j < (sizeof(siop_led_off) /
  			    sizeof(siop_led_off[0])); j++)
  				sc->sc_c.sc_script[
  				   Ent_led_off / sizeof(siop_led_off[0]) + j
  				   ] = siop_htoc32(&sc->sc_c, siop_led_off[j]);
  		}
  	}
  	sc->script_free_lo = sizeof(siop_script) / sizeof(siop_script[0]);
  	sc->script_free_hi = sc->sc_c.ram_size / 4;
  	sc->sc_ntargets = 0;
  
  	/* 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_c.sc_dev.dv_xname, lunsw->lunsw_off);
  #endif
  		TAILQ_REMOVE(&sc->lunsw_list, lunsw, next);
  		free(lunsw, M_DEVBUF, 0);
  	}
  	TAILQ_INIT(&sc->lunsw_list);
  	/* restore reselect switch */
  	for (i = 0; i < sc->sc_c.sc_link.adapter_buswidth; i++) {
  		struct siop_target *target;
  		if (sc->sc_c.targets[i] == NULL)
  			continue;
  #ifdef SIOP_DEBUG
  		printf("%s: restore sw for target %d\n",
  				sc->sc_c.sc_dev.dv_xname, i);
  #endif
  		target = (struct siop_target *)sc->sc_c.targets[i];
  		free(target->lunsw, M_DEVBUF, 0);
  		target->lunsw = siop_get_lunsw(sc);
  		if (target->lunsw == NULL) {
  			printf("%s: can't alloc lunsw for target %d\n",
  			    sc->sc_c.sc_dev.dv_xname, i);
  			break;
  		}
  		siop_add_reselsw(sc, i);
  	}
  
  	/* start script */
  	if ((sc->sc_c.features & SF_CHIP_RAM) == 0) {
  		bus_dmamap_sync(sc->sc_c.sc_dmat, sc->sc_c.sc_scriptdma, 0,
  		    PAGE_SIZE, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
  	}
  	bus_space_write_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh, SIOP_DSP,
  	    sc->sc_c.sc_scriptaddr + Ent_reselect);
  }
  
  #if 0
  #define CALL_SCRIPT(ent) do {\
  	printf ("start script DSA 0x%lx DSP 0x%lx\n", \
  	    siop_cmd->cmd_c.dsa, \
  	    sc->sc_c.sc_scriptaddr + ent); \
  bus_space_write_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh, SIOP_DSP, sc->sc_c.sc_scriptaddr + ent); \
  } while (0)
  #else
  #define CALL_SCRIPT(ent) do {\
  bus_space_write_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh, SIOP_DSP, sc->sc_c.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 = 0;
  	u_int32_t irqcode;
  	int need_reset = 0;
  	int offset, target, lun, tag;
  	bus_addr_t dsa;
  	struct siop_cbd *cbdp;
  	int restart = 0;
  
  	istat = bus_space_read_1(sc->sc_c.sc_rt, sc->sc_c.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_c.sc_rt, sc->sc_c.sc_rh,
  		    SIOP_ISTAT, ISTAT_INTF);
  	}
  	if ((istat &(ISTAT_DIP | ISTAT_SIP | ISTAT_ABRT)) ==
  	    (ISTAT_DIP | ISTAT_ABRT)) {
  		/* clear abort */
  		bus_space_write_1(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  		    SIOP_ISTAT, 0);
  	}
  	/* use DSA to find the current siop_cmd */
  	siop_cmd = NULL;
  	dsa = bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh, SIOP_DSA);
  	TAILQ_FOREACH(cbdp, &sc->cmds, next) {
  		if (dsa >= SIOP_DMA_DVA(cbdp->xfers) &&
  	    	    dsa < SIOP_DMA_DVA(cbdp->xfers) + PAGE_SIZE) {
  			dsa -= SIOP_DMA_DVA(cbdp->xfers);
  			siop_cmd = &cbdp->cmds[dsa / sizeof(struct siop_xfer)];
  			siop_table_sync(siop_cmd,
  			    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
  			break;
  		}
  	}
  	if (siop_cmd) {
  		xs = siop_cmd->cmd_c.xs;
  		siop_target = (struct siop_target *)siop_cmd->cmd_c.siop_target;
  		target = siop_cmd->cmd_c.xs->sc_link->target;
  		lun = siop_cmd->cmd_c.xs->sc_link->lun;
  		tag = siop_cmd->cmd_c.tag;
  		siop_lun = siop_target->siop_lun[lun];
  #ifdef DIAGNOSTIC
  		if (siop_cmd->cmd_c.status != CMDST_ACTIVE &&
  		    siop_cmd->cmd_c.status != CMDST_SENSE_ACTIVE) {
   			printf("siop_cmd (lun %d) for DSA 0x%x "
  			    "not active (%d)\n", lun, (u_int)dsa,
  			    siop_cmd->cmd_c.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_c.sc_rt, sc->sc_c.sc_rh,
  		    SIOP_DSTAT);
  		if (dstat & DSTAT_ABRT) {
  			/* was probably generated by a bus reset IOCTL */
  			if ((dstat & DSTAT_DFE) == 0)
  				siop_clearfifo(&sc->sc_c);
  			goto reset;
  		}
  		if (dstat & DSTAT_SSI) {
  			printf("single step dsp 0x%08x dsa 0x08%x\n",
  			    (int)(bus_space_read_4(sc->sc_c.sc_rt,
  			    sc->sc_c.sc_rh, SIOP_DSP) -
  			    sc->sc_c.sc_scriptaddr),
  			    bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  				SIOP_DSA));
  			if ((dstat & ~(DSTAT_DFE | DSTAT_SSI)) == 0 &&
  			    (istat & ISTAT_SIP) == 0) {
  				bus_space_write_1(sc->sc_c.sc_rt,
  				    sc->sc_c.sc_rh, SIOP_DCNTL,
  				    bus_space_read_1(sc->sc_c.sc_rt,
  				    sc->sc_c.sc_rh, SIOP_DCNTL) | DCNTL_STD);
  			}
  			return 1;
  		}
  
  		if (dstat & ~(DSTAT_SIR | DSTAT_DFE | DSTAT_SSI)) {
  			printf("%s: DMA IRQ:", sc->sc_c.sc_dev.dv_xname);
  			if (dstat & DSTAT_IID)
  				printf(" illegal instruction");
  			if (dstat & DSTAT_BF)
  				printf(" bus fault");
  			if (dstat & DSTAT_MDPE)
  				printf(" parity");
  			if (dstat & DSTAT_DFE)
  				printf(" DMA fifo empty");
  			else
  				siop_clearfifo(&sc->sc_c);
  			printf(", DSP=0x%x DSA=0x%x: ",
  			    (int)(bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  				SIOP_DSP) - sc->sc_c.sc_scriptaddr),
  			    bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh, SIOP_DSA));
  			if (siop_cmd)
  				printf("last msg_in=0x%x status=0x%x\n",
  				    siop_cmd->cmd_tables->msg_in[0],
  				    siop_ctoh32(&sc->sc_c,
  					siop_cmd->cmd_tables->status));
  			else
  				printf("current DSA invalid\n");
  			need_reset = 1;
  		}
  	}
  	if (istat & ISTAT_SIP) {
  		if (istat & ISTAT_DIP)
  			delay(10);
  		/*
  		 * Can't read sist0 & sist1 independently, or we have to
  		 * insert delay
  		 */
  		sist = bus_space_read_2(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  		    SIOP_SIST0);
  		sstat1 = bus_space_read_1(sc->sc_c.sc_rt, sc->sc_c.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, sstat1,
  		    bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh, SIOP_DSA),
  		    (u_long)(bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  			SIOP_DSP) -
  		    sc->sc_c.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_c.sc_dev.dv_xname);
  			printf("scsi gross error\n");
  			goto reset;
  		}
  		if ((sist & SIST0_MA) && need_reset == 0) {
  			if (siop_cmd) {
  				int scratcha0;
  				/* XXX Why read DSTAT again? */
  				dstat = bus_space_read_1(sc->sc_c.sc_rt,
  				    sc->sc_c.sc_rh, SIOP_DSTAT);
  				/*
  				 * first restore DSA, in case we were in a S/G
  				 * operation.
  				 */
  				bus_space_write_4(sc->sc_c.sc_rt,
  				    sc->sc_c.sc_rh,
  				    SIOP_DSA, siop_cmd->cmd_c.dsa);
  				scratcha0 = bus_space_read_1(sc->sc_c.sc_rt,
  				    sc->sc_c.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). Compute resid and
  				 * just go to status, the command should
  				 * terminate.
  				 */
  					INCSTAT(siop_stat_intr_shortxfer);
  					if (scratcha0 & A_flag_data)
  						siop_ma(&siop_cmd->cmd_c);
  					else if ((dstat & DSTAT_DFE) == 0)
  						siop_clearfifo(&sc->sc_c);
  					CALL_SCRIPT(Ent_status);
  					return 1;
  				case SSTAT1_PHASE_MSGIN:
  				/*
  				 * target may be ready to disconnect
  				 * Compute resid which would be used later
  				 * if a save data pointer is needed.
  				 */
  					INCSTAT(siop_stat_intr_xferdisc);
  					if (scratcha0 & A_flag_data)
  						siop_ma(&siop_cmd->cmd_c);
  					else if ((dstat & DSTAT_DFE) == 0)
  						siop_clearfifo(&sc->sc_c);
  					bus_space_write_1(sc->sc_c.sc_rt,
  					    sc->sc_c.sc_rh, SIOP_SCRATCHA,
  					    scratcha0 & ~A_flag_data);
  					CALL_SCRIPT(Ent_msgin);
  					return 1;
  				}
  				printf("%s: unexpected phase mismatch %d\n",
  				    sc->sc_c.sc_dev.dv_xname,
  				    sstat1 & SSTAT1_PHASE_MASK);
  			} else {
  				printf("%s: phase mismatch without command\n",
  				    sc->sc_c.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_c.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->cmd_c.status = CMDST_DONE;
  				xs->error = XS_SELTIMEOUT;
  				goto end;
  			} else {
  				printf("%s: selection timeout without "
  				    "command\n", sc->sc_c.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->cmd_tables->status =
  				    siop_htoc32(&sc->sc_c, SCSI_CHECK);
  				goto end;
  			}
  			printf("%s: unexpected disconnect without "
  			    "command\n", sc->sc_c.sc_dev.dv_xname);
  			goto reset;
  		}
  		if (sist & (SIST1_SBMC << 8)) {
  			/* SCSI bus mode change */
  			if (siop_modechange(&sc->sc_c) == 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_c.sc_rt, sc->sc_c.sc_rh,
  			    SIOP_DSP,
  			    bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  			    SIOP_DSP) - 8);
  			return 1;
  		}
  		/* Else it's an unhandled exception (for now). */
  		printf("%s: unhandled scsi interrupt, sist=0x%x sstat1=0x%x "
  		    "DSA=0x%x DSP=0x%x\n", sc->sc_c.sc_dev.dv_xname,
  		    sist, sstat1,
  		    bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh, SIOP_DSA),
  		    (int)(bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  			SIOP_DSP) - sc->sc_c.sc_scriptaddr));
  		if (siop_cmd) {
  			siop_cmd->cmd_c.status = CMDST_DONE;
  			xs->error = XS_SELTIMEOUT;
  			goto end;
  		}
  		need_reset = 1;
  	} else {
  		sist = sstat1 = 0;
  	}
  	if (need_reset) {
  reset:
  		/* fatal error, reset the bus */
  		siop_resetbus(&sc->sc_c);
  		/* no table to flush here */
  		return 1;
  	}
  
  scintr:
  	if ((istat & ISTAT_DIP) && (dstat & DSTAT_SIR)) { /* script interrupt */
  		irqcode = bus_space_read_4(sc->sc_c.sc_rt, sc->sc_c.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_c.sc_dev.dv_xname, irqcode);
  				goto reset;
  			}
  			if (siop_cmd->cmd_c.status != CMDST_ACTIVE &&
  			    siop_cmd->cmd_c.status != CMDST_SENSE_ACTIVE) {
  				printf("%s: command with invalid status "
  				    "(IRQ code 0x%x current status %d) !\n",
  				    sc->sc_c.sc_dev.dv_xname,
  				    irqcode, siop_cmd->cmd_c.status);
  				xs = NULL;
  			}
  		}
  		switch(irqcode) {
  		case A_int_err:
  			printf("error, DSP=0x%x\n",
  			    (int)(bus_space_read_4(sc->sc_c.sc_rt,
  			    sc->sc_c.sc_rh, SIOP_DSP) - sc->sc_c.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_c.sc_dev.dv_xname);
  			goto reset;
  		case A_int_resellun:
  			INCSTAT(siop_stat_intr_lunresel);
  			target = bus_space_read_1(sc->sc_c.sc_rt,
  			    sc->sc_c.sc_rh, SIOP_SCRATCHA) & 0xf;
  			lun = bus_space_read_1(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  			    SIOP_SCRATCHA + 1);
  			tag = bus_space_read_1(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  			    SIOP_SCRATCHA + 2);
  			siop_target =
  			    (struct siop_target *)sc->sc_c.targets[target];
  			if (siop_target == NULL) {
  				printf("%s: reselect with invalid target %d\n",
  				    sc->sc_c.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_c.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_c.sc_dev.dv_xname,
  				    target, lun, tag);
  				goto reset;
  			}
  			siop_cmd = siop_lun->siop_tag[tag].active;
  			bus_space_write_4(sc->sc_c.sc_rt, sc->sc_c.sc_rh,
  			    SIOP_DSP, siop_cmd->cmd_c.dsa +
  			    sizeof(struct siop_common_xfer) +
  			    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_c.sc_dev.dv_xname);
  			goto reset;
  		case A_int_msgin:
  		{
  			int msgin = bus_space_read_1(sc->sc_c.sc_rt,
  			    sc->sc_c.sc_rh, SIOP_SFBR);
  			if (msgin == MSG_MESSAGE_REJECT) {
  				int msg, extmsg;
  				if (siop_cmd->cmd_tables->msg_out[0] & 0x80) {
  					/*
  					 * message was part of a identify +
  					 * something else. Identify shouldn't
  					 * have been rejected.
  					 */
  					msg =
  					    siop_cmd->cmd_tables->msg_out[1];
  					extmsg =
  					    siop_cmd->cmd_tables->msg_out[3];
  				} else {
  					msg = siop_cmd->cmd_tables->msg_out[0];
  					extmsg =
  					    siop_cmd->cmd_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_c.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 */
  					if ((siop_target->target_c.flags &
  					   TARF_SYNC) == 0) {
  						siop_target->target_c.status =
  						    TARST_OK;
  						siop_update_xfer_mode(&sc->sc_c,
  						    target);
  						/* no table to flush here */
  						CALL_SCRIPT(Ent_msgin_ack);
  						return 1;
  					}
  					siop_target->target_c.status =
  					    TARST_SYNC_NEG;
  					siop_sdtr_msg(&siop_cmd->cmd_c, 0,
  					    sc->sc_c.st_minsync,
  					    sc->sc_c.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 */
  					siop_target->target_c.offset = 0;
  					siop_target->target_c.period = 0;
  					siop_target->target_c.status = TARST_OK;
  					siop_update_xfer_mode(&sc->sc_c,
  					    target);
  					/* no table to flush here */
  					CALL_SCRIPT(Ent_msgin_ack);
  					return 1;
  				} else if (msg == MSG_EXTENDED &&
  				    extmsg == MSG_EXT_PPR) {
  					/* PPR negotiation rejected */
  					siop_target->target_c.offset = 0;
  					siop_target->target_c.period = 0;
  					siop_target->target_c.status = TARST_ASYNC;
  					siop_target->target_c.flags &= ~(TARF_DT | TARF_ISDT);
  					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_c.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 (msgin == MSG_IGN_WIDE_RESIDUE) {
  			/* use the extmsgdata table to get the second byte */
  				siop_cmd->cmd_tables->t_extmsgdata.count =
  				    siop_htoc32(&sc->sc_c, 1);
  				siop_table_sync(siop_cmd,
  				    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
  				CALL_SCRIPT(Ent_get_extmsgdata);
  				return 1;
  			}
  			if (xs)
  				sc_print_addr(xs->sc_link);
  			else
  				printf("%s: ", sc->sc_c.sc_dev.dv_xname);
  			printf("unhandled message 0x%x\n",
  			    siop_cmd->cmd_tables->msg_in[0]);
  			siop_cmd->cmd_tables->msg_out[0] = MSG_MESSAGE_REJECT;
  			siop_cmd->cmd_tables->t_msgout.count =
  			    siop_htoc32(&sc->sc_c, 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->cmd_tables->msg_in[2],
  			    siop_cmd->cmd_tables->msg_in[1]);
  #endif
  			if (siop_cmd->cmd_tables->msg_in[1] >
  			    sizeof(siop_cmd->cmd_tables->msg_in) - 2)
  				printf("%s: extended message too big (%d)\n",
  				    sc->sc_c.sc_dev.dv_xname,
  				    siop_cmd->cmd_tables->msg_in[1]);
  			siop_cmd->cmd_tables->t_extmsgdata.count =
  			    siop_htoc32(&sc->sc_c,
  			        siop_cmd->cmd_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->cmd_tables->msg_in[2]);
  			for (i = 3; i < 2 + siop_cmd->cmd_tables->msg_in[1];
  			    i++)
  				printf(" 0x%x",
  				    siop_cmd->cmd_tables->msg_in[i]);
  			printf("\n");
  			}
  #endif
  			if (siop_cmd->cmd_tables->msg_in[0] ==
  			    MSG_IGN_WIDE_RESIDUE) {
  			/* we got the second byte of MSG_IGN_WIDE_RESIDUE */
  				if (siop_cmd->cmd_tables->msg_in[3] != 1)
  					printf("MSG_IGN_WIDE_RESIDUE: "
  					    "bad len %d\n",
  					    siop_cmd->cmd_tables->msg_in[3]);
  				switch (siop_iwr(&siop_cmd->cmd_c)) {
  				case SIOP_NEG_MSGOUT:
  					siop_table_sync(siop_cmd,
  					    BUS_DMASYNC_PREREAD |
  					    BUS_DMASYNC_PREWRITE);
  					CALL_SCRIPT(Ent_send_msgout);
  					return(1);
  				case SIOP_NEG_ACK:
  					CALL_SCRIPT(Ent_msgin_ack);
  					return(1);
  				default:
  					panic("invalid retval from "
  					    "siop_iwr()");
  				}
  				return(1);
  			}
  			if (siop_cmd->cmd_tables->msg_in[2] == MSG_EXT_WDTR) {
  				switch (siop_wdtr_neg(&siop_cmd->cmd_c)) {
  				case SIOP_NEG_MSGOUT:
  					siop_update_scntl3(sc,
  					    siop_cmd->cmd_c.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->cmd_c.siop_target);
  					CALL_SCRIPT(Ent_msgin_ack);
  					return(1);
  				default:
  					panic("invalid retval from "
  					    "siop_wdtr_neg()");
  				}
  				return(1);
  			}
  			if (siop_cmd->cmd_tables->msg_in[2] == MSG_EXT_SDTR) {
  				switch (siop_sdtr_neg(&siop_cmd->cmd_c)) {
  				case SIOP_NEG_MSGOUT:
  					siop_update_scntl3(sc,
  					    siop_cmd->cmd_c.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->cmd_c.siop_target);
  					CALL_SCRIPT(Ent_msgin_ack);
  					return(1);
  				default:
  					panic("invalid retval from "
  					    "siop_sdtr_neg()");
  				}
  				return(1);
  			}
  			if (siop_cmd->cmd_tables->msg_in[2] == MSG_EXT_PPR) {
  				switch (siop_ppr_neg(&siop_cmd->cmd_c)) {
  				case SIOP_NEG_MSGOUT:
  					siop_update_scntl3(sc,
  					    siop_cmd->cmd_c.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->cmd_c.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->cmd_tables->msg_out[0] = MSG_MESSAGE_REJECT;
  			siop_cmd->cmd_tables->t_msgout.count =
  			    siop_htoc32(&sc->sc_c, 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_c.sc_rt,
  			    sc->sc_c.sc_rh, SIOP_SCRATCHA + 1);
  #ifdef SIOP_DEBUG_DR
  			printf("disconnect offset %d\n", offset);
  #endif
  			siop_sdp(&siop_cmd->cmd_c, offset);
  			/* we start again with no offset */
  			siop_cmd->saved_offset = SIOP_NOOFFSET;
  			siop_table_sync(siop_cmd,
  			    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
  			CALL_SCRIPT(Ent_script_sched);
  			return 1;
  		case A_int_saveoffset:
  			INCSTAT(siop_stat_intr_saveoffset);
  			offset = bus_space_read_1(sc->sc_c.sc_rt,
  			    sc->sc_c.sc_rh, SIOP_SCRATCHA + 1);
  #ifdef SIOP_DEBUG_DR
  			printf("saveoffset offset %d\n", offset);
  #endif
  			siop_cmd->saved_offset = offset;
  			CALL_SCRIPT(Ent_script_sched);
  			return 1;
  		case A_int_resfail:
  			printf("reselect failed\n");
  			/* check if we can put some command in scheduler */
  			siop_start(sc);
  			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_c.sc_dev.dv_xname,
  				    (u_long)siop_cmd->cmd_c.dsa);
  				siop_cmd->cmd_c.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->cmd_c.dsa,
  			    siop_ctoh32(&sc->sc_c, siop_cmd->cmd_tables->id),
  			    siop_cmd->cmd_tables->msg_in[0],
  			    siop_ctoh32(&sc->sc_c,
  				siop_cmd->cmd_tables->status));
  #endif
  			INCSTAT(siop_stat_intr_done);
  			/* update resid.  */
  			offset = bus_space_read_1(sc->sc_c.sc_rt,
  			    sc->sc_c.sc_rh, SIOP_SCRATCHA + 1);
  			/*
  			 * if we got a disconnect between the last data phase
  			 * and the status phase, offset will be 0. In this
  			 * case, siop_cmd->saved_offset will have the proper
  			 * value if it got updated by the controller
  			 */
  			if (offset == 0 && 
  			    siop_cmd->saved_offset != SIOP_NOOFFSET)
  				offset = siop_cmd->saved_offset;
  			siop_update_resid(&siop_cmd->cmd_c, offset);
  			if (siop_cmd->cmd_c.status == CMDST_SENSE_ACTIVE)
  				siop_cmd->cmd_c.status = CMDST_SENSE_DONE;
  			else
  				siop_cmd->cmd_c.status = CMDST_DONE;
  			goto end;
  		default:
  			printf("unknown irqcode %x\n", irqcode);
  			if (xs) {
  				xs->error = XS_SELTIMEOUT;
  				goto end;
  			}
  			goto reset;
  		}
  		return 1;
  	} else
  		irqcode = 0;
  	/* We can get here if ISTAT_DIP and DSTAT_DFE are the only bits set. */
  	/* But that *SHOULDN'T* happen. It does on powerpc (at least).	     */
  	printf("%s: siop_intr() - we should not be here!\n"
  	    "   istat = 0x%x, dstat = 0x%x, sist = 0x%x, sstat1 = 0x%x\n"
  	    "   need_reset = %x, irqcode = %x, siop_cmd %s\n",
  	    sc->sc_c.sc_dev.dv_xname,
  	    istat, dstat, sist, sstat1, need_reset, irqcode,
  	    (siop_cmd == NULL) ? "== NULL" : "!= NULL");
  	goto reset; /* Where we should have gone in the first place! */
  end:
  	/*
  	 * restart the script now if command completed properly
  	 * Otherwise wait for siop_scsicmd_end(), we may need to cleanup the
  	 * queue
  	 */
  	xs->status = siop_ctoh32(&sc->sc_c, siop_cmd->cmd_tables->status);
  	if (xs->status == SCSI_OK)
  		CALL_SCRIPT(Ent_script_sched);
  	else
  		restart = 1;
  	siop_lun->siop_tag[tag].active = NULL;
  	siop_scsicmd_end(siop_cmd);
  	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->cmd_c.xs;
  	struct siop_softc *sc = (struct siop_softc *)siop_cmd->cmd_c.siop_sc;
  	struct siop_lun *siop_lun =
  	    ((struct siop_target*)sc->sc_c.targets[xs->sc_link->target])->siop_lun[xs->sc_link->lun];
  
  	/*
  	 * If the command is re-queued (SENSE, QUEUE_FULL) it
  	 * must get a new timeout, so delete existing timeout now.
  	 */
  	timeout_del(&siop_cmd->cmd_c.xs->stimeout);
  
  	switch(xs->status) {
  	case SCSI_OK:
  		xs->error = (siop_cmd->cmd_c.status == CMDST_DONE) ?
  		    XS_NOERROR : XS_SENSE;
  		break;
  	case SCSI_BUSY:
  		xs->error = XS_BUSY;
  		break;
  	case SCSI_CHECK:
  		if (siop_cmd->cmd_c.status == CMDST_SENSE_DONE) {
  			/* request sense on a request sense ? */
  			printf("%s: request sense failed\n",
  			    sc->sc_c.sc_dev.dv_xname);
  			xs->error = XS_DRIVER_STUFFUP;
  		} else {
  			siop_cmd->cmd_c.status = CMDST_SENSE;
  		}
  		break;
  	case SCSI_QUEUE_FULL:
  		/*
  		 * Device didn't queue the command. We have to retry
  		 * it.  We insert it into the urgent list, hoping to
  		 * preserve order.  But unfortunately, 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_c.sc_dev.dv_xname,
  		    xs->sc_link->target,
  		    xs->sc_link->lun, siop_cmd->cmd_c.tag);
  #endif
  		siop_lun->lun_flags |= SIOP_LUNF_FULL;
  		siop_cmd->cmd_c.status = CMDST_READY;
  		siop_setuptables(&siop_cmd->cmd_c);
  		siop_table_sync(siop_cmd, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
  		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->cmd_c.status != CMDST_SENSE_DONE &&
  	    xs->flags & (SCSI_DATA_IN | SCSI_DATA_OUT)) {
  		bus_dmamap_sync(sc->sc_c.sc_dmat, siop_cmd->cmd_c.dmamap_data, 0,
  		    siop_cmd->cmd_c.dmamap_data->dm_mapsize,
  		    (xs->flags & SCSI_DATA_IN) ?
  		    BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
  		bus_dmamap_unload(sc->sc_c.sc_dmat, siop_cmd->cmd_c.dmamap_data);
  	}
  	if (siop_cmd->cmd_c.status == CMDST_SENSE) {
  		/* issue a request sense for this target */
  		struct scsi_sense *cmd = (struct scsi_sense *)&siop_cmd->cmd_c.siop_tables->xscmd;
  		int error;
  		bzero(cmd, sizeof(*cmd));
  		siop_cmd->cmd_c.siop_tables->cmd.count =
  		   siop_htoc32(&sc->sc_c, sizeof(struct scsi_sense));
  		cmd->opcode = REQUEST_SENSE;
  		cmd->byte2 = xs->sc_link->lun << 5;
  		cmd->unused[0] = cmd->unused[1] = 0;
  		cmd->length = sizeof(struct scsi_sense_data);
  		cmd->control = 0;
  		siop_cmd->cmd_c.flags &= ~CMDFL_TAG;
  		error = bus_dmamap_load(sc->sc_c.sc_dmat,
  		    siop_cmd->cmd_c.dmamap_data,
  		    siop_cmd->cmd_c.sense, sizeof(struct scsi_sense_data),
  		    NULL, BUS_DMA_NOWAIT);
  		if (error) {
  			printf("%s: unable to load data DMA map "
  			    "(for SENSE): %d\n",
  			    sc->sc_c.sc_dev.dv_xname, error);
  			xs->error = XS_DRIVER_STUFFUP;
  			goto out;
  		}
  		bus_dmamap_sync(sc->sc_c.sc_dmat, siop_cmd->cmd_c.dmamap_data,
  		    0, siop_cmd->cmd_c.dmamap_data->dm_mapsize,
  		    BUS_DMASYNC_PREREAD);
  
  		siop_setuptables(&siop_cmd->cmd_c);
  		siop_table_sync(siop_cmd, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
  		/* arrange for the cmd to be handled now */
  		TAILQ_INSERT_HEAD(&sc->urgent_list, siop_cmd, next);
  		return;
  	} else if (siop_cmd->cmd_c.status == CMDST_SENSE_DONE) {
  		bus_dmamap_sync(sc->sc_c.sc_dmat, siop_cmd->cmd_c.dmamap_data,
  		    0, siop_cmd->cmd_c.dmamap_data->dm_mapsize,
  		    BUS_DMASYNC_POSTREAD);
  		bus_dmamap_unload(sc->sc_c.sc_dmat, siop_cmd->cmd_c.dmamap_data);
  		bcopy(siop_cmd->cmd_c.sense, &xs->sense, sizeof(xs->sense));
  	}
  out:
  	siop_lun->lun_flags &= ~SIOP_LUNF_FULL;
  #if 0
  	if (xs->resid != 0)
  		printf("resid %d datalen %d\n", xs->resid, xs->datalen);
  #endif
  	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 = (struct siop_softc *)siop_cmd->cmd_c.siop_sc;
  	int target = siop_cmd->cmd_c.xs->sc_link->target;
  	int lun = siop_cmd->cmd_c.xs->sc_link->lun;
  	int tag = siop_cmd->cmd_tables->msg_out[2];
  	struct siop_lun *siop_lun =
  	    ((struct siop_target*)sc->sc_c.targets[target])->siop_lun[lun];
  
  #ifdef SIOP_DEBUG
  	printf("%s:%d:%d: tag message %d (%d) rejected (status %d)\n",
  	    sc->sc_c.sc_dev.dv_xname, target, lun, tag, siop_cmd->cmd_c.tag,
  	    siop_cmd->cmd_c.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_c.sc_dev.dv_xname,
  		    target, lun, siop_lun->siop_tag[0].active->cmd_c.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->cmd_c.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->cmd_c.dsa + sizeof(struct siop_common_xfer) +
  		    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 lossage to upper layer.
   * As the upper layer may requeue immediately 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_c.sc_dev.dv_xname);
  	/* stop, reset and restart the chip */
  	siop_reset(sc);
  	TAILQ_INIT(&reset_list);
  	/*
  	 * Process all commands: first commands being executed
  	 */
  	for (target = 0; target < sc->sc_c.sc_link.adapter_buswidth;
  	    target++) {
  		if (sc->sc_c.targets[target] == NULL)
  			continue;
  		for (lun = 0; lun < 8; lun++) {
  			struct siop_target *siop_target =
  			    (struct siop_target *)sc->sc_c.targets[target];
  			siop_lun = siop_target->siop_lun[lun];
  			if (siop_lun == NULL)
  				continue;
  			siop_lun->lun_flags &= ~SIOP_LUNF_FULL;
  			for (tag = 0; tag <
  			    ((sc->sc_c.targets[target]->flags & TARF_TAG) ?
  			    SIOP_NTAG : 1);
  			    tag++) {
  				siop_cmd = siop_lun->siop_tag[tag].active;
  				if (siop_cmd == NULL)
  					continue;
  				siop_lun->siop_tag[tag].active = NULL;
  				TAILQ_INSERT_TAIL(&reset_list, siop_cmd, next);
  				sc_print_addr(siop_cmd->cmd_c.xs->sc_link);
  				printf("cmd %p (tag %d) added to reset list\n",
  				    siop_cmd, tag);
  			}
  		}
  		if (sc->sc_c.targets[target]->status != TARST_PROBING) {
  			sc->sc_c.targets[target]->status = TARST_ASYNC;
  			sc->sc_c.targets[target]->flags &= ~TARF_ISWIDE;
  			sc->sc_c.targets[target]->period =
  			    sc->sc_c.targets[target]->offset = 0;
  			siop_update_xfer_mode(&sc->sc_c, target);
  		}
  	}
  	/* 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);
  		TAILQ_REMOVE(&sc->urgent_list, siop_cmd, next);
  		TAILQ_INSERT_TAIL(&reset_list, siop_cmd, next);
  		sc_print_addr(siop_cmd->cmd_c.xs->sc_link);
  		printf("cmd %p added to reset list from urgent list\n",
  		    siop_cmd);
  	}
  	/* Then commands 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);
  		TAILQ_REMOVE(&sc->ready_list, siop_cmd, next);
  		TAILQ_INSERT_TAIL(&reset_list, siop_cmd, next);
  		sc_print_addr(siop_cmd->cmd_c.xs->sc_link);
  		printf("cmd %p added to reset list from ready list\n",
  		    siop_cmd);
  	}
  
  	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->cmd_c.flags &= ~CMDFL_TAG;
  		siop_cmd->cmd_c.xs->error =
  		    (siop_cmd->cmd_c.flags & CMDFL_TIMEOUT)
  		    ? XS_TIMEOUT : XS_RESET;
  		siop_cmd->cmd_c.xs->status = SCSI_SIOP_NOCHECK;
  		sc_print_addr(siop_cmd->cmd_c.xs->sc_link);
  		printf("cmd %p (status %d) reset",
  		    siop_cmd, siop_cmd->cmd_c.status);
  		if (siop_cmd->cmd_c.status == CMDST_SENSE ||
  		    siop_cmd->cmd_c.status == CMDST_SENSE_ACTIVE) 
  			siop_cmd->cmd_c.status = CMDST_SENSE_DONE;
  		else
  			siop_cmd->cmd_c.status = CMDST_DONE;
  		printf(" with status %d, xs->error %d\n",
  		    siop_cmd->cmd_c.status, siop_cmd->cmd_c.xs->error);
  		TAILQ_REMOVE(&reset_list, siop_cmd, next);
  		siop_scsicmd_end(siop_cmd);
  	}
  }
  
  void *
  siop_cmd_get(void *cookie)
  {
  	struct siop_softc *sc = cookie;
  	struct siop_cmd *siop_cmd;
  	int s;
  
  	/* Look if a ccb is available. */
  	s = splbio();
  	siop_cmd = TAILQ_FIRST(&sc->free_list);
  	if (siop_cmd != NULL) {
  		TAILQ_REMOVE(&sc->free_list, siop_cmd, next);
  #ifdef DIAGNOSTIC
  		if (siop_cmd->cmd_c.status != CMDST_FREE)
  			panic("siop_scsicmd: new cmd not free");
  #endif
  		siop_cmd->cmd_c.status = CMDST_READY;
  	}
  	splx(s);
  
  	return (siop_cmd);
  }
  
  void
  siop_cmd_put(void *cookie, void *io)
  {
  	struct siop_softc *sc = cookie;
  	struct siop_cmd *siop_cmd = io;
  	int s;
  
  	s = splbio();
  	siop_cmd->cmd_c.status = CMDST_FREE;
  	TAILQ_INSERT_TAIL(&sc->free_list, siop_cmd, next);
  	splx(s);
  }
  
  int
  siop_scsiprobe(struct scsi_link *link)
  {
  	struct siop_softc *sc = (struct siop_softc *)link->adapter_softc;
  	struct siop_target *siop_target;
  	const int target = link->target;
  	const int lun = link->lun;
  	int i;
  
  #ifdef SIOP_DEBUG
  	printf("%s:%d:%d: probe\n",
  	    sc->sc_c.sc_dev.dv_xname, target, lun);
  #endif
  
  	/* XXX locking */
  
  	siop_target = (struct siop_target*)sc->sc_c.targets[target];
  	if (siop_target == NULL) {
  		siop_target = malloc(sizeof(*siop_target), M_DEVBUF,
  		    M_WAITOK | M_CANFAIL | M_ZERO);
  		if (siop_target == NULL) {
  			printf("%s: can't malloc memory for target %d\n",
  			    sc->sc_c.sc_dev.dv_xname, target);
  			return (ENOMEM);
  		}
  
  		siop_target->target_c.status = TARST_PROBING;
  		siop_target->target_c.flags  = 0;
  		siop_target->target_c.id =
  		    sc->sc_c.clock_div << 24; /* scntl3 */
  		siop_target->target_c.id |=  target << 16; /* id */
  		/* siop_target->target_c.id |= 0x0 << 8; scxfer is 0 */
  
  		/* get a lun switch script */
  		siop_target->lunsw = siop_get_lunsw(sc);
  		if (siop_target->lunsw == NULL) {
  			printf("%s: can't alloc lunsw for target %d\n",
  			    sc->sc_c.sc_dev.dv_xname, target);
  			free(siop_target, M_DEVBUF, sizeof *siop_target);
  			return (ENOMEM);
  		}
  		for (i = 0; i < 8; i++)
  			siop_target->siop_lun[i] = NULL;
  
  		sc->sc_c.targets[target] =
  		    (struct siop_common_target *)siop_target;
  
  		siop_add_reselsw(sc, target);
  	}
  
  	if (siop_target->siop_lun[lun] == NULL) {
  		siop_target->siop_lun[lun] =
  		    malloc(sizeof(struct siop_lun), M_DEVBUF,
  		    M_WAITOK | M_CANFAIL | M_ZERO);
  		if (siop_target->siop_lun[lun] == NULL) {
  			printf("%s: can't alloc siop_lun for "
  			    "target %d lun %d\n",
  			    sc->sc_c.sc_dev.dv_xname, target, lun);
  			return (ENOMEM);
  		}
  	}
  
  	return (0);
  }
  
  void
  siop_scsicmd(xs)
  	struct scsi_xfer *xs;
  {
  	struct siop_softc *sc = (struct siop_softc *)xs->sc_link->adapter_softc;
  	struct siop_cmd *siop_cmd;
  	struct siop_target *siop_target;
  	int s, error, i, j;
  	const int target = xs->sc_link->target;
  	const int lun = xs->sc_link->lun;
  
  #ifdef SIOP_DEBUG_SCHED
  	printf("starting cmd for %d:%d\n", target, lun);
  #endif
  
  	siop_target = (struct siop_target*)sc->sc_c.targets[target];
  	siop_cmd = xs->io;
  
  	/*
  	 * The xs may have been restarted by the scsi layer, so ensure the ccb
  	 * starts in the proper state.
  	 */
  	siop_cmd->cmd_c.status = CMDST_READY;
  
  	/* Always reset xs->stimeout, lest we timeout_del() with trash */
  	timeout_set(&xs->stimeout, siop_timeout, siop_cmd);
  
  	siop_cmd->cmd_c.siop_target = sc->sc_c.targets[target];
  	siop_cmd->cmd_c.xs = xs;
  	siop_cmd->cmd_c.flags = 0;
  
  	bzero(&siop_cmd->cmd_c.siop_tables->xscmd,
  	    sizeof(siop_cmd->cmd_c.siop_tables->xscmd));
  	bcopy(xs->cmd, &siop_cmd->cmd_c.siop_tables->xscmd, xs->cmdlen);
  	siop_cmd->cmd_c.siop_tables->cmd.count =
  	    siop_htoc32(&sc->sc_c, xs->cmdlen);
  
  	/* load the DMA maps */
  	if (xs->flags & (SCSI_DATA_IN | SCSI_DATA_OUT)) {
  		error = bus_dmamap_load(sc->sc_c.sc_dmat,
  		    siop_cmd->cmd_c.dmamap_data, xs->data, xs->datalen,
  		    NULL, BUS_DMA_NOWAIT | BUS_DMA_STREAMING |
  		    ((xs->flags & SCSI_DATA_IN) ?
  			BUS_DMA_READ : BUS_DMA_WRITE));
  		if (error) {
  			printf("%s: unable to load data DMA map: %d\n",
  			    sc->sc_c.sc_dev.dv_xname, error);
  			xs->error = XS_DRIVER_STUFFUP;
  			scsi_done(xs);
  			return;
  		}
  		bus_dmamap_sync(sc->sc_c.sc_dmat,
  		    siop_cmd->cmd_c.dmamap_data, 0,
  		    siop_cmd->cmd_c.dmamap_data->dm_mapsize,
  		    (xs->flags & SCSI_DATA_IN) ?
  		    BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
  	}
  
  	siop_setuptables(&siop_cmd->cmd_c);
  	siop_cmd->saved_offset = SIOP_NOOFFSET;
  	siop_table_sync(siop_cmd,
  	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
  
  	/* Negotiate transfer parameters on first non-polling command. */
  	if (((xs->flags & SCSI_POLL) == 0) &&
  	    siop_target->target_c.status == TARST_PROBING)
  		siop_target->target_c.status = TARST_ASYNC;
  
  	s = splbio();
  	TAILQ_INSERT_TAIL(&sc->ready_list, siop_cmd, next);
  	siop_start(sc);
  	if ((xs->flags & SCSI_POLL) == 0) {
  		splx(s);
  		return;
  	}
  
  	/* Poll for command completion. */
  	for(i = xs->timeout; i > 0; i--) {
  		siop_intr(sc);
  		if ((xs->flags & ITSDONE) == 0) {
  			delay(1000);
  			continue;
  		}
  		if (xs->cmd->opcode == INQUIRY && xs->error == XS_NOERROR) {
  			struct scsi_inquiry_data *inqbuf =
  			    (struct scsi_inquiry_data *)xs->data;
  		 	if ((inqbuf->device & SID_QUAL) == SID_QUAL_BAD_LU)
  				break;
  			/* 
  			 * Allocate cbd's to hold maximum openings worth of
  			 * commands. Do this now because doing it dynamically in
  			 * siop_startcmd may cause calls to bus_dma* functions
  			 * in interrupt context.
  			 */
  			for (j = 0; j < SIOP_NTAG; j += SIOP_NCMDPB)
  				siop_morecbd(sc);
  
  			/*
  			 * Set TARF_DT here because if it is turned off during
  			 * PPR, it must STAY off!
  			 */
  			if ((lun == 0) && (sc->sc_c.features & SF_BUS_ULTRA3))
  				sc->sc_c.targets[target]->flags |= TARF_DT;
  			/*
  			 * Can't do lun 0 here, because flags are not set yet.
  			 * But have to do other lun's here because they never go
  			 * through TARST_ASYNC.
  			 */
  			if (lun > 0)
  				siop_add_dev(sc, target, lun);
  		}
  		break;
  	}
  	if (i == 0) {
  		siop_timeout(siop_cmd);
  		while ((xs->flags & ITSDONE) == 0)
  			siop_intr(sc);
  	}
  
  	splx(s);
  }
  
  void
  siop_start(sc)
  	struct siop_softc *sc;
  {
  	struct siop_cmd *siop_cmd, *next_siop_cmd;
  	struct siop_lun *siop_lun;
  	struct siop_xfer *siop_xfer;
  	u_int32_t dsa;
  	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->cmd_c.status != CMDST_READY &&
  		    siop_cmd->cmd_c.status != CMDST_SENSE)
  			panic("siop: non-ready cmd in ready list");
  #endif	
  		target = siop_cmd->cmd_c.xs->sc_link->target;
  		lun = siop_cmd->cmd_c.xs->sc_link->lun;
  		siop_lun =
  			((struct siop_target*)sc->sc_c.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->cmd_c.status == CMDST_READY)
  			continue;
  		/* find a free tag if needed */
  		if (siop_cmd->cmd_c.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->cmd_c.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->cmd_c.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 slots, 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->cmd_c.dsa);
  #endif
  		/* Ok, we can add the tag message */
  		if (tag > 0) {
  #ifdef DIAGNOSTIC
  			int msgcount = siop_ctoh32(&sc->sc_c,
  			    siop_cmd->cmd_tables->t_msgout.count);
  			if (msgcount != 1)
  				printf("%s:%d:%d: tag %d with msgcount %d\n",
  				    sc->sc_c.sc_dev.dv_xname, target, lun, tag,
  				    msgcount);
  #endif
  			siop_cmd->cmd_tables->msg_out[1] = MSG_SIMPLE_Q_TAG;
  			siop_cmd->cmd_tables->msg_out[2] = tag;
  			siop_cmd->cmd_tables->t_msgout.count =
  			    siop_htoc32(&sc->sc_c, 3);
  		}
  		/* note that we started a new command */
  		newcmd = 1;
  		/* mark command as active */
  		if (siop_cmd->cmd_c.status == CMDST_READY) {
  			siop_cmd->cmd_c.status = CMDST_ACTIVE;
  		} else if (siop_cmd->cmd_c.status == CMDST_SENSE) {
  			siop_cmd->cmd_c.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->cmd_c.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_common_xfer) +
  			    Ent_ldsa_reload_dsa);
  		/* CMD script: MOVE MEMORY addr */
  		siop_xfer = (struct siop_xfer*)siop_cmd->cmd_tables;
  		siop_xfer->resel[E_ldsa_abs_slot_Used[0]] =
  		    siop_htoc32(&sc->sc_c, sc->sc_c.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_common_xfer) + Ent_ldsa_select);
  		/* handle timeout */
  		if (siop_cmd->cmd_c.status == CMDST_ACTIVE) {
  			if ((siop_cmd->cmd_c.xs->flags & SCSI_POLL) == 0) {
  				/* start expire timer */
  				timeout_add_msec(&siop_cmd->cmd_c.xs->stimeout,
  				    siop_cmd->cmd_c.xs->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_c.sc_rt, sc->sc_c.sc_rh,
  	    SIOP_ISTAT, ISTAT_SIGP);
  	/* and wait for IRQ */
  }
  
  void
  siop_timeout(v)
  	void *v;
  {
  	struct siop_cmd *siop_cmd = v;
  	struct siop_softc *sc = (struct siop_softc *)siop_cmd->cmd_c.siop_sc;
  	int s;
  
  	/* deactivate callout */
  	timeout_del(&siop_cmd->cmd_c.xs->stimeout);
  
  	sc_print_addr(siop_cmd->cmd_c.xs->sc_link);
  	printf("timeout on SCSI command 0x%x\n",
  	    siop_cmd->cmd_c.xs->cmd->opcode);
  
  	s = splbio();
  	/* reset the scsi bus */
  	siop_resetbus(&sc->sc_c);
  	siop_cmd->cmd_c.flags |= CMDFL_TIMEOUT;
  	siop_handle_reset(sc);
  	splx(s);
  }
  
  #ifdef DUMP_SCRIPT
  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,
  		    siop_ctoh32(&sc->sc_c, sc->sc_c.sc_script[i]),
  		    siop_ctoh32(&sc->sc_c, sc->sc_c.sc_script[i+1]));
  		if ((siop_ctoh32(&sc->sc_c,
  		     sc->sc_c.sc_script[i]) & 0xe0000000) == 0xc0000000) {
  			i++;
  			printf(" 0x%08x", siop_ctoh32(&sc->sc_c,
  			    sc->sc_c.sc_script[i+1]));
  		}
  		printf("\n");
  	}
  }
  #endif
  
  void
  siop_morecbd(sc)
  	struct siop_softc *sc;
  {
  	int error, off, i, j, s;
  	struct siop_cbd *newcbd;
  	struct siop_xfer *xfers, *xfer;
  	bus_addr_t dsa;
  	u_int32_t *scr;
  	size_t sense_size = roundup(sizeof(struct scsi_sense_data), 16);
  
  	/* allocate a new list head */
  	newcbd = malloc(sizeof(struct siop_cbd), M_DEVBUF, M_NOWAIT | M_ZERO);
  	if (newcbd == NULL) {
  		printf("%s: can't allocate memory for command descriptors "
  		    "head\n", sc->sc_c.sc_dev.dv_xname);
  		return;
  	}
  
  	/* allocate cmd list */
  	newcbd->cmds = mallocarray(SIOP_NCMDPB, sizeof(struct siop_cmd),
  	    M_DEVBUF, M_NOWAIT | M_ZERO);
  	if (newcbd->cmds == NULL) {
  		printf("%s: can't allocate memory for command descriptors\n",
  		    sc->sc_c.sc_dev.dv_xname);
  		goto bad3;
  	}
  
  	newcbd->xfers = siop_dmamem_alloc(sc, PAGE_SIZE);
  	if (newcbd->xfers == NULL) {
  		printf("%s: unable to allocate cbd xfer DMA memory\n",
  		    sc->sc_c.sc_dev.dv_xname);
  		goto bad2;
  	}
  	xfers = SIOP_DMA_KVA(newcbd->xfers);
  
  	newcbd->sense = siop_dmamem_alloc(sc, sense_size * SIOP_NCMDPB);
  	if (newcbd->sense == NULL) {
  		printf("%s: unable to allocate cbd sense DMA memory\n",
  		    sc->sc_c.sc_dev.dv_xname);
  		goto bad1;
  	}
  
  	for (i = 0; i < SIOP_NCMDPB; i++) {
  		error = bus_dmamap_create(sc->sc_c.sc_dmat, MAXPHYS, SIOP_NSG,
  		    MAXPHYS, 0, BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW,
  		    &newcbd->cmds[i].cmd_c.dmamap_data);
  		if (error) {
  			printf("%s: unable to create data DMA map for cbd: "
  			    "error %d\n",
  			    sc->sc_c.sc_dev.dv_xname, error);
  			goto bad0;
  		}
  	}
  
  	/* Use two loops since bailing out above releases allocated memory */
  	off = (sc->sc_c.features & SF_CHIP_BE) ? 3 : 0;
  	for (i = 0; i < SIOP_NCMDPB; i++) {
  		newcbd->cmds[i].cmd_c.siop_sc = &sc->sc_c;
  		newcbd->cmds[i].siop_cbdp = newcbd;
  		xfer = &xfers[i];
  		newcbd->cmds[i].cmd_tables = (struct siop_common_xfer *)xfer;
  		bzero(newcbd->cmds[i].cmd_tables, sizeof(struct siop_xfer));
  		dsa = SIOP_DMA_DVA(newcbd->xfers) +
  		    i * sizeof(struct siop_xfer);
  		newcbd->cmds[i].cmd_c.dsa = dsa;
  		newcbd->cmds[i].cmd_c.status = CMDST_FREE;
  		newcbd->cmds[i].cmd_c.sense = (struct scsi_sense_data *)(
  		    i * sense_size +
  		    (u_int8_t *)SIOP_DMA_KVA(newcbd->sense));
  		xfer->siop_tables.t_msgout.count= siop_htoc32(&sc->sc_c, 1);
  		xfer->siop_tables.t_msgout.addr = siop_htoc32(&sc->sc_c, dsa);
  		xfer->siop_tables.t_msgin.count= siop_htoc32(&sc->sc_c, 1);
  		xfer->siop_tables.t_msgin.addr = siop_htoc32(&sc->sc_c,
  		    dsa + offsetof(struct siop_common_xfer, msg_in));
  		xfer->siop_tables.t_extmsgin.count= siop_htoc32(&sc->sc_c, 2);
  		xfer->siop_tables.t_extmsgin.addr = siop_htoc32(&sc->sc_c,
  		    dsa + offsetof(struct siop_common_xfer, msg_in) + 1);
  		xfer->siop_tables.t_extmsgdata.addr = siop_htoc32(&sc->sc_c,
  		    dsa + offsetof(struct siop_common_xfer, msg_in) + 3);
  		xfer->siop_tables.t_status.count= siop_htoc32(&sc->sc_c, 1);
  		xfer->siop_tables.t_status.addr = siop_htoc32(&sc->sc_c,
  		    dsa + offsetof(struct siop_common_xfer, status) + off);
  		xfer->siop_tables.cmd.count = siop_htoc32(&sc->sc_c, 0);
  		xfer->siop_tables.cmd.addr = siop_htoc32(&sc->sc_c,
  		    dsa + offsetof(struct siop_common_xfer, xscmd));
  		/* The select/reselect script */
  		scr = &xfer->resel[0];
  		for (j = 0; j < sizeof(load_dsa) / sizeof(load_dsa[0]); j++)
  			scr[j] = siop_htoc32(&sc->sc_c, load_dsa[j]);
  		/*
  		 * 0x78000000 is a 'move data8 to reg'. data8 is the second
  		 * octet, reg offset is the third.
  		 */
  		scr[Ent_rdsa0 / 4] = siop_htoc32(&sc->sc_c,
  		    0x78100000 | ((dsa & 0x000000ff) <<  8));
  		scr[Ent_rdsa1 / 4] = siop_htoc32(&sc->sc_c,
  		    0x78110000 | ( dsa & 0x0000ff00       ));
  		scr[Ent_rdsa2 / 4] = siop_htoc32(&sc->sc_c,
  		    0x78120000 | ((dsa & 0x00ff0000) >>  8));
  		scr[Ent_rdsa3 / 4] = siop_htoc32(&sc->sc_c,
  		    0x78130000 | ((dsa & 0xff000000) >> 16));
  		scr[E_ldsa_abs_reselected_Used[0]] = siop_htoc32(&sc->sc_c,
  		    sc->sc_c.sc_scriptaddr + Ent_reselected);
  		scr[E_ldsa_abs_reselect_Used[0]] = siop_htoc32(&sc->sc_c,
  		    sc->sc_c.sc_scriptaddr + Ent_reselect);
  		scr[E_ldsa_abs_selected_Used[0]] = siop_htoc32(&sc->sc_c,
  		    sc->sc_c.sc_scriptaddr + Ent_selected);
  		scr[E_ldsa_abs_data_Used[0]] = siop_htoc32(&sc->sc_c,
  		    dsa + sizeof(struct siop_common_xfer) + Ent_ldsa_data);
  		/* JUMP foo, IF FALSE - used by MOVE MEMORY to clear the slot */
  		scr[Ent_ldsa_data / 4] = siop_htoc32(&sc->sc_c, 0x80000000);
  		s = splbio();
  		TAILQ_INSERT_TAIL(&sc->free_list, &newcbd->cmds[i], next);
  		splx(s);
  #ifdef SIOP_DEBUG
  		printf("tables[%d]: in=0x%x out=0x%x status=0x%x "
  		    "offset=0x%x\n", i,
  		    siop_ctoh32(&sc->sc_c,
  			newcbd->cmds[i].cmd_tables->t_msgin.addr),
  		    siop_ctoh32(&sc->sc_c,
  			newcbd->cmds[i].cmd_tables->t_msgout.addr),
  		    siop_ctoh32(&sc->sc_c,
  			newcbd->cmds[i].cmd_tables->t_status.addr));
  #endif
  	}
  	s = splbio();
  	TAILQ_INSERT_TAIL(&sc->cmds, newcbd, next);
  	splx(s);
  	return;
  bad0:
  	while (--i >= 0) {
  		bus_dmamap_destroy(sc->sc_c.sc_dmat,
  		    newcbd->cmds[i].cmd_c.dmamap_data);
  	}
  	siop_dmamem_free(sc, newcbd->sense);
  bad1:
  	siop_dmamem_free(sc, newcbd->xfers);
  bad2:
  	free(newcbd->cmds, M_DEVBUF, SIOP_NCMDPB * sizeof(struct siop_cmd));
  bad3:
  	free(newcbd, M_DEVBUF, sizeof *newcbd);
  }
  
  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 | M_ZERO);
  	if (lunsw == NULL)
  		return NULL;
  #ifdef SIOP_DEBUG
  	printf("allocating lunsw at offset %d\n", sc->script_free_lo);
  #endif
  	if (sc->sc_c.features & SF_CHIP_RAM) {
  		bus_space_write_region_4(sc->sc_c.sc_ramt, sc->sc_c.sc_ramh,
  		    sc->script_free_lo * 4, lun_switch,
  		    sizeof(lun_switch) / sizeof(lun_switch[0]));
  		bus_space_write_4(sc->sc_c.sc_ramt, sc->sc_c.sc_ramh,
  		    (sc->script_free_lo + E_abs_lunsw_return_Used[0]) * 4,
  		    sc->sc_c.sc_scriptaddr + Ent_lunsw_return);
  	} else {
  		for (i = 0; i < sizeof(lun_switch) / sizeof(lun_switch[0]);
  		    i++)
  			sc->sc_c.sc_script[sc->script_free_lo + i] =
  			    siop_htoc32(&sc->sc_c, lun_switch[i]);
  		sc->sc_c.sc_script[
  		    sc->script_free_lo + E_abs_lunsw_return_Used[0]] =
  		    siop_htoc32(&sc->sc_c,
  			sc->sc_c.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;
  	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,j;
  	struct siop_target *siop_target;
  	struct siop_lun *siop_lun;
  
  	siop_target = (struct siop_target *)sc->sc_c.targets[target];
  	/*
  	 * add an entry to resel switch
  	 */
  	siop_script_sync(sc, BUS_DMASYNC_POSTWRITE);
  	for (i = 0; i < 15; i++) {
  		siop_target->reseloff = Ent_resel_targ0 / 4 + i * 2;
  		if ((siop_script_read(sc, siop_target->reseloff) & 0xff)
  		    == 0xff) { /* it's free */
  #ifdef SIOP_DEBUG
  			printf("siop: target %d slot %d offset %d\n",
  			    target, i, siop_target->reseloff);
  #endif
  			/* JUMP abs_foo, IF target | 0x80; */
  			siop_script_write(sc, siop_target->reseloff,
  			    0x800c0080 | target);
  			siop_script_write(sc, siop_target->reseloff + 1,
  			    sc->sc_c.sc_scriptaddr +
  			    siop_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 = siop_target->siop_lun[i];
  		if (siop_lun == NULL)
  			continue;
  		if (siop_lun->reseloff > 0) {
  			siop_lun->reseloff = 0;
  			for (j = 0; j < SIOP_NTAG; j++)
  				siop_lun->siop_tag[j].reseloff = 0;
  			siop_add_dev(sc, target, i);
  		}
  	}
  	siop_update_scntl3(sc, sc->sc_c.targets[target]);
  	siop_script_sync(sc, BUS_DMASYNC_PREWRITE);
  }
  
  void
  siop_update_scntl3(sc, _siop_target)
  	struct siop_softc *sc;
  	struct siop_common_target *_siop_target;
  {
  	struct siop_target *siop_target = (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->target_c.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->target_c.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_target *siop_target =
  	    (struct siop_target *)sc->sc_c.targets[target];
  	struct siop_lun *siop_lun = siop_target->siop_lun[lun];
  	int i, ntargets;
  
  	if (siop_lun->reseloff > 0)
  		return;
  	lunsw = siop_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 SIOP_DEBUG
  		printf("%s:%d:%d: can't allocate a lun sw slot\n",
  		    sc->sc_c.sc_dev.dv_xname, target, lun);
  #endif
  		return;
  	}
  	/* count how many free targets we still have to probe */
  	ntargets =  (sc->sc_c.sc_link.adapter_buswidth - 1) - 1 - sc->sc_ntargets;
  
  	/*
  	 * we need 8 bytes for the lun sw additional entry, and
  	 * eventually sizeof(tag_switch) for the tag switch entry.
  	 * Keep enough 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])) >=
  	    ((siop_target->target_c.flags & TARF_TAG) ?
  	    sc->script_free_hi - (sizeof(tag_switch) / sizeof(tag_switch[0])) :
  	    sc->script_free_hi)) {
  		/*
  		 * not enough space, probably not worth dealing with it.
  		 * We can hold 13 tagged-queuing capable devices in the 4k RAM.
  		 */
  #ifdef SIOP_DEBUG
  		printf("%s:%d:%d: not enough memory for a lun sw slot\n",
  		    sc->sc_c.sc_dev.dv_xname, target, lun);
  #endif
  		return;
  	}
  #ifdef SIOP_DEBUG
  	printf("%s:%d:%d: allocate lun sw entry\n",
  	    sc->sc_c.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 (siop_target->target_c.flags & TARF_TAG) {
  		/* we need a tag switch */
  		sc->script_free_hi -=
  		    sizeof(tag_switch) / sizeof(tag_switch[0]);
  		if (sc->sc_c.features & SF_CHIP_RAM) {
  			bus_space_write_region_4(sc->sc_c.sc_ramt,
  			    sc->sc_c.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_c.sc_script[sc->script_free_hi + i] =
  				    siop_htoc32(&sc->sc_c, tag_switch[i]);
  			}
  		}
  		siop_script_write(sc,
  		    siop_lun->reseloff + 1,
  		    sc->sc_c.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 =
  		    siop_target->siop_lun[lun]->reseloff;
  	}
  	siop_script_sync(sc, BUS_DMASYNC_PREWRITE);
  }
  
  void
  siop_scsifree(struct scsi_link *link)
  {
  	struct siop_softc *sc = link->adapter_softc;
  	int target = link->target;
  	int lun = link->lun;
  	int i;
  	struct siop_target *siop_target;
  
  #ifdef SIOP_DEBUG
  		printf("%s:%d:%d: free lun sw entry\n",
  		    sc->sc_c.sc_dev.dv_xname, target, lun);
  #endif
  
  	siop_target = (struct siop_target *)sc->sc_c.targets[target];
  	free(siop_target->siop_lun[lun], M_DEVBUF, 0);
  	siop_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 (siop_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_c.sc_dev.dv_xname, target, lun,
  	    siop_target->lunsw->lunsw_off);
  #endif
  	/*
  	 * nothing here, free the target struct and resel
  	 * switch entry
  	 */
  	siop_script_write(sc, siop_target->reseloff, 0x800c00ff);
  	siop_script_sync(sc, BUS_DMASYNC_PREWRITE);
  	TAILQ_INSERT_TAIL(&sc->lunsw_list, siop_target->lunsw, next);
  	free(sc->sc_c.targets[target], M_DEVBUF, 0);
  	sc->sc_c.targets[target] = NULL;
  	sc->sc_ntargets--;
  }
  
  #ifdef SIOP_STATS
  void
  siop_printstats(void)
  {
  	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_saveoffset %d\n", siop_stat_intr_saveoffset);
  	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
  
  struct siop_dmamem *
  siop_dmamem_alloc(struct siop_softc *sc, size_t size)
  {
  	struct siop_dmamem *sdm;
  	int nsegs;
  
  	sdm = malloc(sizeof(*sdm), M_DEVBUF, M_NOWAIT | M_ZERO);
  	if (sdm == NULL)
  		return (NULL);
  
  	sdm->sdm_size = size;
  
  	if (bus_dmamap_create(sc->sc_c.sc_dmat, size, 1, size, 0,
  	    BUS_DMA_NOWAIT | BUS_DMA_ALLOCNOW, &sdm->sdm_map) != 0)
  		goto sdmfree;
  
  	if (bus_dmamem_alloc(sc->sc_c.sc_dmat, size, PAGE_SIZE, 0,
  	    &sdm->sdm_seg, 1, &nsegs, BUS_DMA_NOWAIT | BUS_DMA_ZERO) != 0)
  		goto destroy;
  
  	if (bus_dmamem_map(sc->sc_c.sc_dmat, &sdm->sdm_seg, nsegs, size,
  	    &sdm->sdm_kva, BUS_DMA_NOWAIT | BUS_DMA_COHERENT) != 0)
  		goto free;
  
  	if (bus_dmamap_load(sc->sc_c.sc_dmat, sdm->sdm_map, sdm->sdm_kva,
  	    size, NULL, BUS_DMA_NOWAIT) != 0)
  		goto unmap;
  
  	return (sdm);
  
  unmap:
  	bus_dmamem_unmap(sc->sc_c.sc_dmat, sdm->sdm_kva, size);
  free:
  	bus_dmamem_free(sc->sc_c.sc_dmat, &sdm->sdm_seg, 1);
  destroy:
  	bus_dmamap_destroy(sc->sc_c.sc_dmat, sdm->sdm_map);
  sdmfree:
  	free(sdm, M_DEVBUF, sizeof *sdm);
  
  	return (NULL);
  }
  
  void
  siop_dmamem_free(struct siop_softc *sc, struct siop_dmamem *sdm)
  {
  	bus_dmamap_unload(sc->sc_c.sc_dmat, sdm->sdm_map);
  	bus_dmamem_unmap(sc->sc_c.sc_dmat, sdm->sdm_kva, sdm->sdm_size);
  	bus_dmamem_free(sc->sc_c.sc_dmat, &sdm->sdm_seg, 1);
  	bus_dmamap_destroy(sc->sc_c.sc_dmat, sdm->sdm_map);
  	free(sdm, M_DEVBUF, sizeof *sdm);
  }
  
  