text: /*-
   * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   *
   * Copyright (c) 2000, 2001 Michael Smith
   * Copyright (c) 2000 BSDi
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
   *
   *	$FreeBSD$
   */
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/malloc.h>
  #include <sys/kernel.h>
  #include <sys/bus.h>
  #include <sys/conf.h>
  #include <sys/ctype.h>
  #include <sys/ioccom.h>
  #include <sys/stat.h>
  
  #include <machine/bus.h>
  #include <machine/resource.h>
  #include <sys/rman.h>
  
  #include <cam/cam.h>
  #include <cam/cam_ccb.h>
  #include <cam/cam_periph.h>
  #include <cam/cam_sim.h>
  #include <cam/cam_xpt_sim.h>
  #include <cam/scsi/scsi_all.h>
  #include <cam/scsi/scsi_message.h>
  
  #include <dev/pci/pcireg.h>
  #include <dev/pci/pcivar.h>
  
  #include <dev/mly/mlyreg.h>
  #include <dev/mly/mlyio.h>
  #include <dev/mly/mlyvar.h>
  #include <dev/mly/mly_tables.h>
  
  static int	mly_probe(device_t dev);
  static int	mly_attach(device_t dev);
  static int	mly_pci_attach(struct mly_softc *sc);
  static int	mly_detach(device_t dev);
  static int	mly_shutdown(device_t dev);
  static void	mly_intr(void *arg);
  
  static int	mly_sg_map(struct mly_softc *sc);
  static void	mly_sg_map_helper(void *arg, bus_dma_segment_t *segs, int nseg, int error);
  static int	mly_mmbox_map(struct mly_softc *sc);
  static void	mly_mmbox_map_helper(void *arg, bus_dma_segment_t *segs, int nseg, int error);
  static void	mly_free(struct mly_softc *sc);
  
  static int	mly_get_controllerinfo(struct mly_softc *sc);
  static void	mly_scan_devices(struct mly_softc *sc);
  static void	mly_rescan_btl(struct mly_softc *sc, int bus, int target);
  static void	mly_complete_rescan(struct mly_command *mc);
  static int	mly_get_eventstatus(struct mly_softc *sc);
  static int	mly_enable_mmbox(struct mly_softc *sc);
  static int	mly_flush(struct mly_softc *sc);
  static int	mly_ioctl(struct mly_softc *sc, struct mly_command_ioctl *ioctl, void **data, 
  			  size_t datasize, u_int8_t *status, void *sense_buffer, size_t *sense_length);
  static void	mly_check_event(struct mly_softc *sc);
  static void	mly_fetch_event(struct mly_softc *sc);
  static void	mly_complete_event(struct mly_command *mc);
  static void	mly_process_event(struct mly_softc *sc, struct mly_event *me);
  static void	mly_periodic(void *data);
  
  static int	mly_immediate_command(struct mly_command *mc);
  static int	mly_start(struct mly_command *mc);
  static void	mly_done(struct mly_softc *sc);
  static void	mly_complete(struct mly_softc *sc);
  static void	mly_complete_handler(void *context, int pending);
  
  static int	mly_alloc_command(struct mly_softc *sc, struct mly_command **mcp);
  static void	mly_release_command(struct mly_command *mc);
  static void	mly_alloc_commands_map(void *arg, bus_dma_segment_t *segs, int nseg, int error);
  static int	mly_alloc_commands(struct mly_softc *sc);
  static void	mly_release_commands(struct mly_softc *sc);
  static void	mly_map_command(struct mly_command *mc);
  static void	mly_unmap_command(struct mly_command *mc);
  
  static int	mly_cam_attach(struct mly_softc *sc);
  static void	mly_cam_detach(struct mly_softc *sc);
  static void	mly_cam_rescan_btl(struct mly_softc *sc, int bus, int target);
  static void	mly_cam_action(struct cam_sim *sim, union ccb *ccb);
  static int	mly_cam_action_io(struct cam_sim *sim, struct ccb_scsiio *csio);
  static void	mly_cam_poll(struct cam_sim *sim);
  static void	mly_cam_complete(struct mly_command *mc);
  static struct cam_periph *mly_find_periph(struct mly_softc *sc, int bus, int target);
  static int	mly_name_device(struct mly_softc *sc, int bus, int target);
  
  static int	mly_fwhandshake(struct mly_softc *sc);
  
  static void	mly_describe_controller(struct mly_softc *sc);
  #ifdef MLY_DEBUG
  static void	mly_printstate(struct mly_softc *sc);
  static void	mly_print_command(struct mly_command *mc);
  static void	mly_print_packet(struct mly_command *mc);
  static void	mly_panic(struct mly_softc *sc, char *reason);
  static void	mly_timeout(void *arg);
  #endif
  void		mly_print_controller(int controller);
  
  
  static d_open_t		mly_user_open;
  static d_close_t	mly_user_close;
  static d_ioctl_t	mly_user_ioctl;
  static int	mly_user_command(struct mly_softc *sc, struct mly_user_command *uc);
  static int	mly_user_health(struct mly_softc *sc, struct mly_user_health *uh);
  
  #define MLY_CMD_TIMEOUT		20
  
  static device_method_t mly_methods[] = {
      /* Device interface */
      DEVMETHOD(device_probe,	mly_probe),
      DEVMETHOD(device_attach,	mly_attach),
      DEVMETHOD(device_detach,	mly_detach),
      DEVMETHOD(device_shutdown,	mly_shutdown),
      { 0, 0 }
  };
  
  static driver_t mly_pci_driver = {
  	"mly",
  	mly_methods,
  	sizeof(struct mly_softc)
  };
  
  static devclass_t	mly_devclass;
  DRIVER_MODULE(mly, pci, mly_pci_driver, mly_devclass, 0, 0);
  MODULE_DEPEND(mly, pci, 1, 1, 1);
  MODULE_DEPEND(mly, cam, 1, 1, 1);
  
  static struct cdevsw mly_cdevsw = {
  	.d_version =	D_VERSION,
  	.d_open =	mly_user_open,
  	.d_close =	mly_user_close,
  	.d_ioctl =	mly_user_ioctl,
  	.d_name =	"mly",
  };
  
  /********************************************************************************
   ********************************************************************************
                                                                   Device Interface
   ********************************************************************************
   ********************************************************************************/
  
  static struct mly_ident
  {
      u_int16_t		vendor;
      u_int16_t		device;
      u_int16_t		subvendor;
      u_int16_t		subdevice;
      int			hwif;
      char		*desc;
  } mly_identifiers[] = {
      {0x1069, 0xba56, 0x1069, 0x0040, MLY_HWIF_STRONGARM, "Mylex eXtremeRAID 2000"},
      {0x1069, 0xba56, 0x1069, 0x0030, MLY_HWIF_STRONGARM, "Mylex eXtremeRAID 3000"},
      {0x1069, 0x0050, 0x1069, 0x0050, MLY_HWIF_I960RX,    "Mylex AcceleRAID 352"},
      {0x1069, 0x0050, 0x1069, 0x0052, MLY_HWIF_I960RX,    "Mylex AcceleRAID 170"},
      {0x1069, 0x0050, 0x1069, 0x0054, MLY_HWIF_I960RX,    "Mylex AcceleRAID 160"},
      {0, 0, 0, 0, 0, 0}
  };
  
  /********************************************************************************
   * Compare the provided PCI device with the list we support.
   */
  static int
  mly_probe(device_t dev)
  {
      struct mly_ident	*m;
  
      debug_called(1);
  
      for (m = mly_identifiers; m->vendor != 0; m++) {
  	if ((m->vendor == pci_get_vendor(dev)) &&
  	    (m->device == pci_get_device(dev)) &&
  	    ((m->subvendor == 0) || ((m->subvendor == pci_get_subvendor(dev)) &&
  				     (m->subdevice == pci_get_subdevice(dev))))) {
  	    
  	    device_set_desc(dev, m->desc);
  	    return(BUS_PROBE_DEFAULT);	/* allow room to be overridden */
  	}
      }
      return(ENXIO);
  }
  
  /********************************************************************************
   * Initialise the controller and softc
   */
  static int
  mly_attach(device_t dev)
  {
      struct mly_softc	*sc = device_get_softc(dev);
      int			error;
  
      debug_called(1);
  
      sc->mly_dev = dev;
      mtx_init(&sc->mly_lock, "mly", NULL, MTX_DEF);
      callout_init_mtx(&sc->mly_periodic, &sc->mly_lock, 0);
  
  #ifdef MLY_DEBUG
      callout_init_mtx(&sc->mly_timeout, &sc->mly_lock, 0);
      if (device_get_unit(sc->mly_dev) == 0)
  	mly_softc0 = sc;
  #endif    
  
      /*
       * Do PCI-specific initialisation.
       */
      if ((error = mly_pci_attach(sc)) != 0)
  	goto out;
  
      /*
       * Initialise per-controller queues.
       */
      mly_initq_free(sc);
      mly_initq_busy(sc);
      mly_initq_complete(sc);
  
      /*
       * Initialise command-completion task.
       */
      TASK_INIT(&sc->mly_task_complete, 0, mly_complete_handler, sc);
  
      /* disable interrupts before we start talking to the controller */
      MLY_MASK_INTERRUPTS(sc);
  
      /* 
       * Wait for the controller to come ready, handshake with the firmware if required.
       * This is typically only necessary on platforms where the controller BIOS does not
       * run.
       */
      if ((error = mly_fwhandshake(sc)))
  	goto out;
  
      /*
       * Allocate initial command buffers.
       */
      if ((error = mly_alloc_commands(sc)))
  	goto out;
  
      /* 
       * Obtain controller feature information
       */
      MLY_LOCK(sc);
      error = mly_get_controllerinfo(sc);
      MLY_UNLOCK(sc);
      if (error)
  	goto out;
  
      /*
       * Reallocate command buffers now we know how many we want.
       */
      mly_release_commands(sc);
      if ((error = mly_alloc_commands(sc)))
  	goto out;
  
      /*
       * Get the current event counter for health purposes, populate the initial
       * health status buffer.
       */
      MLY_LOCK(sc);
      error = mly_get_eventstatus(sc);
  
      /*
       * Enable memory-mailbox mode.
       */
      if (error == 0)
  	error = mly_enable_mmbox(sc);
      MLY_UNLOCK(sc);
      if (error)
  	goto out;
  
      /*
       * Attach to CAM.
       */
      if ((error = mly_cam_attach(sc)))
  	goto out;
  
      /* 
       * Print a little information about the controller 
       */
      mly_describe_controller(sc);
  
      /*
       * Mark all attached devices for rescan.
       */
      MLY_LOCK(sc);
      mly_scan_devices(sc);
  
      /*
       * Instigate the first status poll immediately.  Rescan completions won't
       * happen until interrupts are enabled, which should still be before
       * the SCSI subsystem gets to us, courtesy of the "SCSI settling delay".
       */
      mly_periodic((void *)sc);
      MLY_UNLOCK(sc);
  
      /*
       * Create the control device.
       */
      sc->mly_dev_t = make_dev(&mly_cdevsw, 0, UID_ROOT, GID_OPERATOR,
  			     S_IRUSR | S_IWUSR, "mly%d", device_get_unit(sc->mly_dev));
      sc->mly_dev_t->si_drv1 = sc;
  
      /* enable interrupts now */
      MLY_UNMASK_INTERRUPTS(sc);
  
  #ifdef MLY_DEBUG
      callout_reset(&sc->mly_timeout, MLY_CMD_TIMEOUT * hz, mly_timeout, sc);
  #endif
  
   out:
      if (error != 0)
  	mly_free(sc);
      return(error);
  }
  
  /********************************************************************************
   * Perform PCI-specific initialisation.
   */
  static int
  mly_pci_attach(struct mly_softc *sc)
  {
      int			i, error;
  
      debug_called(1);
  
      /* assume failure is 'not configured' */
      error = ENXIO;
  
      /* 
       * Verify that the adapter is correctly set up in PCI space.
       */
      pci_enable_busmaster(sc->mly_dev);
  
      /*
       * Allocate the PCI register window.
       */
      sc->mly_regs_rid = PCIR_BAR(0);	/* first base address register */
      if ((sc->mly_regs_resource = bus_alloc_resource_any(sc->mly_dev, 
  	    SYS_RES_MEMORY, &sc->mly_regs_rid, RF_ACTIVE)) == NULL) {
  	mly_printf(sc, "can't allocate register window\n");
  	goto fail;
      }
  
      /* 
       * Allocate and connect our interrupt.
       */
      sc->mly_irq_rid = 0;
      if ((sc->mly_irq = bus_alloc_resource_any(sc->mly_dev, SYS_RES_IRQ, 
  		    &sc->mly_irq_rid, RF_SHAREABLE | RF_ACTIVE)) == NULL) {
  	mly_printf(sc, "can't allocate interrupt\n");
  	goto fail;
      }
      if (bus_setup_intr(sc->mly_dev, sc->mly_irq, INTR_TYPE_CAM | INTR_ENTROPY | INTR_MPSAFE, NULL, mly_intr, sc, &sc->mly_intr)) {
  	mly_printf(sc, "can't set up interrupt\n");
  	goto fail;
      }
  
      /* assume failure is 'out of memory' */
      error = ENOMEM;
  
      /*
       * Allocate the parent bus DMA tag appropriate for our PCI interface.
       * 
       * Note that all of these controllers are 64-bit capable.
       */
      if (bus_dma_tag_create(bus_get_dma_tag(sc->mly_dev),/* PCI parent */
  			   1, 0, 			/* alignment, boundary */
  			   BUS_SPACE_MAXADDR_32BIT,	/* lowaddr */
  			   BUS_SPACE_MAXADDR, 		/* highaddr */
  			   NULL, NULL, 			/* filter, filterarg */
  			   BUS_SPACE_MAXSIZE_32BIT,	/* maxsize */
  			   BUS_SPACE_UNRESTRICTED,	/* nsegments */
  			   BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
  			   BUS_DMA_ALLOCNOW,		/* flags */
  			   NULL,			/* lockfunc */
  			   NULL,			/* lockarg */
  			   &sc->mly_parent_dmat)) {
  	mly_printf(sc, "can't allocate parent DMA tag\n");
  	goto fail;
      }
  
      /*
       * Create DMA tag for mapping buffers into controller-addressable space.
       */
      if (bus_dma_tag_create(sc->mly_parent_dmat, 	/* parent */
  			   1, 0, 			/* alignment, boundary */
  			   BUS_SPACE_MAXADDR,		/* lowaddr */
  			   BUS_SPACE_MAXADDR, 		/* highaddr */
  			   NULL, NULL, 			/* filter, filterarg */
  			   DFLTPHYS,			/* maxsize */
  			   MLY_MAX_SGENTRIES,		/* nsegments */
  			   BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
  			   0,				/* flags */
  			   busdma_lock_mutex,		/* lockfunc */
  			   &sc->mly_lock,		/* lockarg */
  			   &sc->mly_buffer_dmat)) {
  	mly_printf(sc, "can't allocate buffer DMA tag\n");
  	goto fail;
      }
  
      /*
       * Initialise the DMA tag for command packets.
       */
      if (bus_dma_tag_create(sc->mly_parent_dmat,		/* parent */
  			   1, 0, 			/* alignment, boundary */
  			   BUS_SPACE_MAXADDR,		/* lowaddr */
  			   BUS_SPACE_MAXADDR, 		/* highaddr */
  			   NULL, NULL, 			/* filter, filterarg */
  			   sizeof(union mly_command_packet) * MLY_MAX_COMMANDS, 1,	/* maxsize, nsegments */
  			   BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
  			   BUS_DMA_ALLOCNOW,		/* flags */
  			   NULL, NULL,			/* lockfunc, lockarg */
  			   &sc->mly_packet_dmat)) {
  	mly_printf(sc, "can't allocate command packet DMA tag\n");
  	goto fail;
      }
  
      /* 
       * Detect the hardware interface version 
       */
      for (i = 0; mly_identifiers[i].vendor != 0; i++) {
  	if ((mly_identifiers[i].vendor == pci_get_vendor(sc->mly_dev)) &&
  	    (mly_identifiers[i].device == pci_get_device(sc->mly_dev))) {
  	    sc->mly_hwif = mly_identifiers[i].hwif;
  	    switch(sc->mly_hwif) {
  	    case MLY_HWIF_I960RX:
  		debug(1, "set hardware up for i960RX");
  		sc->mly_doorbell_true = 0x00;
  		sc->mly_command_mailbox =  MLY_I960RX_COMMAND_MAILBOX;
  		sc->mly_status_mailbox =   MLY_I960RX_STATUS_MAILBOX;
  		sc->mly_idbr =             MLY_I960RX_IDBR;
  		sc->mly_odbr =             MLY_I960RX_ODBR;
  		sc->mly_error_status =     MLY_I960RX_ERROR_STATUS;
  		sc->mly_interrupt_status = MLY_I960RX_INTERRUPT_STATUS;
  		sc->mly_interrupt_mask =   MLY_I960RX_INTERRUPT_MASK;
  		break;
  	    case MLY_HWIF_STRONGARM:
  		debug(1, "set hardware up for StrongARM");
  		sc->mly_doorbell_true = 0xff;		/* doorbell 'true' is 0 */
  		sc->mly_command_mailbox =  MLY_STRONGARM_COMMAND_MAILBOX;
  		sc->mly_status_mailbox =   MLY_STRONGARM_STATUS_MAILBOX;
  		sc->mly_idbr =             MLY_STRONGARM_IDBR;
  		sc->mly_odbr =             MLY_STRONGARM_ODBR;
  		sc->mly_error_status =     MLY_STRONGARM_ERROR_STATUS;
  		sc->mly_interrupt_status = MLY_STRONGARM_INTERRUPT_STATUS;
  		sc->mly_interrupt_mask =   MLY_STRONGARM_INTERRUPT_MASK;
  		break;
  	    }
  	    break;
  	}
      }
  
      /*
       * Create the scatter/gather mappings.
       */
      if ((error = mly_sg_map(sc)))
  	goto fail;
  
      /*
       * Allocate and map the memory mailbox
       */
      if ((error = mly_mmbox_map(sc)))
  	goto fail;
  
      error = 0;
  	    
  fail:
      return(error);
  }
  
  /********************************************************************************
   * Shut the controller down and detach all our resources.
   */
  static int
  mly_detach(device_t dev)
  {
      int			error;
  
      if ((error = mly_shutdown(dev)) != 0)
  	return(error);
      
      mly_free(device_get_softc(dev));
      return(0);
  }
  
  /********************************************************************************
   * Bring the controller to a state where it can be safely left alone.
   *
   * Note that it should not be necessary to wait for any outstanding commands,
   * as they should be completed prior to calling here.
   *
   * XXX this applies for I/O, but not status polls; we should beware of
   *     the case where a status command is running while we detach.
   */
  static int
  mly_shutdown(device_t dev)
  {
      struct mly_softc	*sc = device_get_softc(dev);
  
      debug_called(1);
  
      MLY_LOCK(sc);
      if (sc->mly_state & MLY_STATE_OPEN) {
  	MLY_UNLOCK(sc);
  	return(EBUSY);
      }
  
      /* kill the periodic event */
      callout_stop(&sc->mly_periodic);
  #ifdef MLY_DEBUG
      callout_stop(&sc->mly_timeout);
  #endif
  
      /* flush controller */
      mly_printf(sc, "flushing cache...");
      printf("%s\n", mly_flush(sc) ? "failed" : "done");
  
      MLY_MASK_INTERRUPTS(sc);
      MLY_UNLOCK(sc);
  
      return(0);
  }
  
  /*******************************************************************************
   * Take an interrupt, or be poked by other code to look for interrupt-worthy
   * status.
   */
  static void
  mly_intr(void *arg)
  {
      struct mly_softc	*sc = (struct mly_softc *)arg;
  
      debug_called(2);
  
      MLY_LOCK(sc);
      mly_done(sc);
      MLY_UNLOCK(sc);
  };
  
  /********************************************************************************
   ********************************************************************************
                                                  Bus-dependant Resource Management
   ********************************************************************************
   ********************************************************************************/
  
  /********************************************************************************
   * Allocate memory for the scatter/gather tables
   */
  static int
  mly_sg_map(struct mly_softc *sc)
  {
      size_t	segsize;
  
      debug_called(1);
  
      /*
       * Create a single tag describing a region large enough to hold all of
       * the s/g lists we will need.
       */
      segsize = sizeof(struct mly_sg_entry) * MLY_MAX_COMMANDS *MLY_MAX_SGENTRIES;
      if (bus_dma_tag_create(sc->mly_parent_dmat,		/* parent */
  			   1, 0, 			/* alignment,boundary */
  			   BUS_SPACE_MAXADDR,		/* lowaddr */
  			   BUS_SPACE_MAXADDR, 		/* highaddr */
  			   NULL, NULL, 			/* filter, filterarg */
  			   segsize, 1,			/* maxsize, nsegments */
  			   BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
  			   BUS_DMA_ALLOCNOW,		/* flags */
  			   NULL, NULL,			/* lockfunc, lockarg */
  			   &sc->mly_sg_dmat)) {
  	mly_printf(sc, "can't allocate scatter/gather DMA tag\n");
  	return(ENOMEM);
      }
  
      /*
       * Allocate enough s/g maps for all commands and permanently map them into
       * controller-visible space.
       *	
       * XXX this assumes we can get enough space for all the s/g maps in one 
       * contiguous slab.
       */
      if (bus_dmamem_alloc(sc->mly_sg_dmat, (void **)&sc->mly_sg_table,
  			 BUS_DMA_NOWAIT, &sc->mly_sg_dmamap)) {
  	mly_printf(sc, "can't allocate s/g table\n");
  	return(ENOMEM);
      }
      if (bus_dmamap_load(sc->mly_sg_dmat, sc->mly_sg_dmamap, sc->mly_sg_table,
  			segsize, mly_sg_map_helper, sc, BUS_DMA_NOWAIT) != 0)
  	return (ENOMEM);
      return(0);
  }
  
  /********************************************************************************
   * Save the physical address of the base of the s/g table.
   */
  static void
  mly_sg_map_helper(void *arg, bus_dma_segment_t *segs, int nseg, int error)
  {
      struct mly_softc	*sc = (struct mly_softc *)arg;
  
      debug_called(1);
  
      /* save base of s/g table's address in bus space */
      sc->mly_sg_busaddr = segs->ds_addr;
  }
  
  /********************************************************************************
   * Allocate memory for the memory-mailbox interface
   */
  static int
  mly_mmbox_map(struct mly_softc *sc)
  {
  
      /*
       * Create a DMA tag for a single contiguous region large enough for the
       * memory mailbox structure.
       */
      if (bus_dma_tag_create(sc->mly_parent_dmat,		/* parent */
  			   1, 0, 			/* alignment,boundary */
  			   BUS_SPACE_MAXADDR,		/* lowaddr */
  			   BUS_SPACE_MAXADDR, 		/* highaddr */
  			   NULL, NULL, 			/* filter, filterarg */
  			   sizeof(struct mly_mmbox), 1,	/* maxsize, nsegments */
  			   BUS_SPACE_MAXSIZE_32BIT,	/* maxsegsize */
  			   BUS_DMA_ALLOCNOW,		/* flags */
  			   NULL, NULL,			/* lockfunc, lockarg */
  			   &sc->mly_mmbox_dmat)) {
  	mly_printf(sc, "can't allocate memory mailbox DMA tag\n");
  	return(ENOMEM);
      }
  
      /*
       * Allocate the buffer
       */
      if (bus_dmamem_alloc(sc->mly_mmbox_dmat, (void **)&sc->mly_mmbox, BUS_DMA_NOWAIT, &sc->mly_mmbox_dmamap)) {
  	mly_printf(sc, "can't allocate memory mailbox\n");
  	return(ENOMEM);
      }
      if (bus_dmamap_load(sc->mly_mmbox_dmat, sc->mly_mmbox_dmamap, sc->mly_mmbox,
  			sizeof(struct mly_mmbox), mly_mmbox_map_helper, sc, 
  			BUS_DMA_NOWAIT) != 0)
  	return (ENOMEM);
      bzero(sc->mly_mmbox, sizeof(*sc->mly_mmbox));
      return(0);
  
  }
  
  /********************************************************************************
   * Save the physical address of the memory mailbox 
   */
  static void
  mly_mmbox_map_helper(void *arg, bus_dma_segment_t *segs, int nseg, int error)
  {
      struct mly_softc	*sc = (struct mly_softc *)arg;
  
      debug_called(1);
  
      sc->mly_mmbox_busaddr = segs->ds_addr;
  }
  
  /********************************************************************************
   * Free all of the resources associated with (sc)
   *
   * Should not be called if the controller is active.
   */
  static void
  mly_free(struct mly_softc *sc)
  {
      
      debug_called(1);
  
      /* Remove the management device */
      destroy_dev(sc->mly_dev_t);
  
      if (sc->mly_intr)
  	bus_teardown_intr(sc->mly_dev, sc->mly_irq, sc->mly_intr);
      callout_drain(&sc->mly_periodic);
  #ifdef MLY_DEBUG
      callout_drain(&sc->mly_timeout);
  #endif
  
      /* detach from CAM */
      mly_cam_detach(sc);
  
      /* release command memory */
      mly_release_commands(sc);
      
      /* throw away the controllerinfo structure */
      if (sc->mly_controllerinfo != NULL)
  	free(sc->mly_controllerinfo, M_DEVBUF);
  
      /* throw away the controllerparam structure */
      if (sc->mly_controllerparam != NULL)
  	free(sc->mly_controllerparam, M_DEVBUF);
  
      /* destroy data-transfer DMA tag */
      if (sc->mly_buffer_dmat)
  	bus_dma_tag_destroy(sc->mly_buffer_dmat);
  
      /* free and destroy DMA memory and tag for s/g lists */
      if (sc->mly_sg_table) {
  	bus_dmamap_unload(sc->mly_sg_dmat, sc->mly_sg_dmamap);
  	bus_dmamem_free(sc->mly_sg_dmat, sc->mly_sg_table, sc->mly_sg_dmamap);
      }
      if (sc->mly_sg_dmat)
  	bus_dma_tag_destroy(sc->mly_sg_dmat);
  
      /* free and destroy DMA memory and tag for memory mailbox */
      if (sc->mly_mmbox) {
  	bus_dmamap_unload(sc->mly_mmbox_dmat, sc->mly_mmbox_dmamap);
  	bus_dmamem_free(sc->mly_mmbox_dmat, sc->mly_mmbox, sc->mly_mmbox_dmamap);
      }
      if (sc->mly_mmbox_dmat)
  	bus_dma_tag_destroy(sc->mly_mmbox_dmat);
  
      /* disconnect the interrupt handler */
      if (sc->mly_irq != NULL)
  	bus_release_resource(sc->mly_dev, SYS_RES_IRQ, sc->mly_irq_rid, sc->mly_irq);
  
      /* destroy the parent DMA tag */
      if (sc->mly_parent_dmat)
  	bus_dma_tag_destroy(sc->mly_parent_dmat);
  
      /* release the register window mapping */
      if (sc->mly_regs_resource != NULL)
  	bus_release_resource(sc->mly_dev, SYS_RES_MEMORY, sc->mly_regs_rid, sc->mly_regs_resource);
  
      mtx_destroy(&sc->mly_lock);
  }
  
  /********************************************************************************
   ********************************************************************************
                                                                   Command Wrappers
   ********************************************************************************
   ********************************************************************************/
  
  /********************************************************************************
   * Fill in the mly_controllerinfo and mly_controllerparam fields in the softc.
   */
  static int
  mly_get_controllerinfo(struct mly_softc *sc)
  {
      struct mly_command_ioctl	mci;
      u_int8_t			status;
      int				error;
  
      debug_called(1);
  
      if (sc->mly_controllerinfo != NULL)
  	free(sc->mly_controllerinfo, M_DEVBUF);
  
      /* build the getcontrollerinfo ioctl and send it */
      bzero(&mci, sizeof(mci));
      sc->mly_controllerinfo = NULL;
      mci.sub_ioctl = MDACIOCTL_GETCONTROLLERINFO;
      if ((error = mly_ioctl(sc, &mci, (void **)&sc->mly_controllerinfo, sizeof(*sc->mly_controllerinfo),
  			   &status, NULL, NULL)))
  	return(error);
      if (status != 0)
  	return(EIO);
  
      if (sc->mly_controllerparam != NULL)
  	free(sc->mly_controllerparam, M_DEVBUF);
  
      /* build the getcontrollerparameter ioctl and send it */
      bzero(&mci, sizeof(mci));
      sc->mly_controllerparam = NULL;
      mci.sub_ioctl = MDACIOCTL_GETCONTROLLERPARAMETER;
      if ((error = mly_ioctl(sc, &mci, (void **)&sc->mly_controllerparam, sizeof(*sc->mly_controllerparam),
  			   &status, NULL, NULL)))
  	return(error);
      if (status != 0)
  	return(EIO);
  
      return(0);
  }
  
  /********************************************************************************
   * Schedule all possible devices for a rescan.
   *
   */
  static void
  mly_scan_devices(struct mly_softc *sc)
  {
      int		bus, target;
  
      debug_called(1);
  
      /*
       * Clear any previous BTL information.
       */
      bzero(&sc->mly_btl, sizeof(sc->mly_btl));
  
      /*
       * Mark all devices as requiring a rescan, and let the next
       * periodic scan collect them. 
       */
      for (bus = 0; bus < sc->mly_cam_channels; bus++)
  	if (MLY_BUS_IS_VALID(sc, bus)) 
  	    for (target = 0; target < MLY_MAX_TARGETS; target++)
  		sc->mly_btl[bus][target].mb_flags = MLY_BTL_RESCAN;
  
  }
  
  /********************************************************************************
   * Rescan a device, possibly as a consequence of getting an event which suggests
   * that it may have changed.
   *
   * If we suffer resource starvation, we can abandon the rescan as we'll be
   * retried.
   */
  static void
  mly_rescan_btl(struct mly_softc *sc, int bus, int target)
  {
      struct mly_command		*mc;
      struct mly_command_ioctl	*mci;
  
      debug_called(1);
  
      /* check that this bus is valid */
      if (!MLY_BUS_IS_VALID(sc, bus))
  	return;
  
      /* get a command */
      if (mly_alloc_command(sc, &mc))
  	return;
  
      /* set up the data buffer */
      if ((mc->mc_data = malloc(sizeof(union mly_devinfo), M_DEVBUF, M_NOWAIT | M_ZERO)) == NULL) {
  	mly_release_command(mc);
  	return;
      }
      mc->mc_flags |= MLY_CMD_DATAIN;
      mc->mc_complete = mly_complete_rescan;
  
      /* 
       * Build the ioctl.
       */
      mci = (struct mly_command_ioctl *)&mc->mc_packet->ioctl;
      mci->opcode = MDACMD_IOCTL;
      mci->addr.phys.controller = 0;
      mci->timeout.value = 30;
      mci->timeout.scale = MLY_TIMEOUT_SECONDS;
      if (MLY_BUS_IS_VIRTUAL(sc, bus)) {
  	mc->mc_length = mci->data_size = sizeof(struct mly_ioctl_getlogdevinfovalid);
  	mci->sub_ioctl = MDACIOCTL_GETLOGDEVINFOVALID;
  	mci->addr.log.logdev = MLY_LOGDEV_ID(sc, bus, target);
  	debug(1, "logical device %d", mci->addr.log.logdev);
      } else {
  	mc->mc_length = mci->data_size = sizeof(struct mly_ioctl_getphysdevinfovalid);
  	mci->sub_ioctl = MDACIOCTL_GETPHYSDEVINFOVALID;
  	mci->addr.phys.lun = 0;
  	mci->addr.phys.target = target;
  	mci->addr.phys.channel = bus;
  	debug(1, "physical device %d:%d", mci->addr.phys.channel, mci->addr.phys.target);
      }
      
      /*
       * Dispatch the command.  If we successfully send the command, clear the rescan
       * bit.
       */
      if (mly_start(mc) != 0) {
  	mly_release_command(mc);
      } else {
  	sc->mly_btl[bus][target].mb_flags &= ~MLY_BTL_RESCAN;	/* success */	
      }
  }
  
  /********************************************************************************
   * Handle the completion of a rescan operation
   */
  static void
  mly_complete_rescan(struct mly_command *mc)
  {
      struct mly_softc				*sc = mc->mc_sc;
      struct mly_ioctl_getlogdevinfovalid		*ldi;
      struct mly_ioctl_getphysdevinfovalid	*pdi;
      struct mly_command_ioctl			*mci;
      struct mly_btl				btl, *btlp;
      int						bus, target, rescan;
  
      debug_called(1);
  
      /*
       * Recover the bus and target from the command.  We need these even in
       * the case where we don't have a useful response.
       */
      mci = (struct mly_command_ioctl *)&mc->mc_packet->ioctl;
      if (mci->sub_ioctl == MDACIOCTL_GETLOGDEVINFOVALID) {
  	bus = MLY_LOGDEV_BUS(sc, mci->addr.log.logdev);
  	target = MLY_LOGDEV_TARGET(sc, mci->addr.log.logdev);
      } else {
  	bus = mci->addr.phys.channel;
  	target = mci->addr.phys.target;
      }
      /* XXX validate bus/target? */
      
      /* the default result is 'no device' */
      bzero(&btl, sizeof(btl));
  
      /* if the rescan completed OK, we have possibly-new BTL data */
      if (mc->mc_status == 0) {
  	if (mc->mc_length == sizeof(*ldi)) {
  	    ldi = (struct mly_ioctl_getlogdevinfovalid *)mc->mc_data;
  	    if ((MLY_LOGDEV_BUS(sc, ldi->logical_device_number) != bus) ||
  		(MLY_LOGDEV_TARGET(sc, ldi->logical_device_number) != target)) {
  		mly_printf(sc, "WARNING: BTL rescan for %d:%d returned data for %d:%d instead\n",
  			   bus, target, MLY_LOGDEV_BUS(sc, ldi->logical_device_number),
  			   MLY_LOGDEV_TARGET(sc, ldi->logical_device_number));
  		/* XXX what can we do about this? */
  	    }
  	    btl.mb_flags = MLY_BTL_LOGICAL;
  	    btl.mb_type = ldi->raid_level;
  	    btl.mb_state = ldi->state;
  	    debug(1, "BTL rescan for %d returns %s, %s", ldi->logical_device_number, 
  		  mly_describe_code(mly_table_device_type, ldi->raid_level),
  		  mly_describe_code(mly_table_device_state, ldi->state));
  	} else if (mc->mc_length == sizeof(*pdi)) {
  	    pdi = (struct mly_ioctl_getphysdevinfovalid *)mc->mc_data;
  	    if ((pdi->channel != bus) || (pdi->target != target)) {
  		mly_printf(sc, "WARNING: BTL rescan for %d:%d returned data for %d:%d instead\n",
  			   bus, target, pdi->channel, pdi->target);
  		/* XXX what can we do about this? */
  	    }
  	    btl.mb_flags = MLY_BTL_PHYSICAL;
  	    btl.mb_type = MLY_DEVICE_TYPE_PHYSICAL;
  	    btl.mb_state = pdi->state;
  	    btl.mb_speed = pdi->speed;
  	    btl.mb_width = pdi->width;
  	    if (pdi->state != MLY_DEVICE_STATE_UNCONFIGURED)
  		sc->mly_btl[bus][target].mb_flags |= MLY_BTL_PROTECTED;
  	    debug(1, "BTL rescan for %d:%d returns %s", bus, target, 
  		  mly_describe_code(mly_table_device_state, pdi->state));
  	} else {
  	    mly_printf(sc, "BTL rescan result invalid\n");
  	}
      }
  
      free(mc->mc_data, M_DEVBUF);
      mly_release_command(mc);
  
      /*
       * Decide whether we need to rescan the device.
       */
      rescan = 0;
  
      /* device type changes (usually between 'nothing' and 'something') */
      btlp = &sc->mly_btl[bus][target];
      if (btl.mb_flags != btlp->mb_flags) {
  	debug(1, "flags changed, rescanning");
  	rescan = 1;
      }
      
      /* XXX other reasons? */
  
      /*
       * Update BTL information.
       */
      *btlp = btl;
  
      /*
       * Perform CAM rescan if required.
       */
      if (rescan)
  	mly_cam_rescan_btl(sc, bus, target);
  }
  
  /********************************************************************************
   * Get the current health status and set the 'next event' counter to suit.
   */
  static int
  mly_get_eventstatus(struct mly_softc *sc)
  {
      struct mly_command_ioctl	mci;
      struct mly_health_status	*mh;
      u_int8_t			status;
      int				error;
  
      /* build the gethealthstatus ioctl and send it */
      bzero(&mci, sizeof(mci));
      mh = NULL;
      mci.sub_ioctl = MDACIOCTL_GETHEALTHSTATUS;
  
      if ((error = mly_ioctl(sc, &mci, (void **)&mh, sizeof(*mh), &status, NULL, NULL)))
  	return(error);
      if (status != 0)
  	return(EIO);
  
      /* get the event counter */
      sc->mly_event_change = mh->change_counter;
      sc->mly_event_waiting = mh->next_event;
      sc->mly_event_counter = mh->next_event;
  
      /* save the health status into the memory mailbox */
      bcopy(mh, &sc->mly_mmbox->mmm_health.status, sizeof(*mh));
  
      debug(1, "initial change counter %d, event counter %d", mh->change_counter, mh->next_event);
      
      free(mh, M_DEVBUF);
      return(0);
  }
  
  /********************************************************************************
   * Enable the memory mailbox mode.
   */
  static int
  mly_enable_mmbox(struct mly_softc *sc)
  {
      struct mly_command_ioctl	mci;
      u_int8_t			*sp, status;
      int				error;
  
      debug_called(1);
  
      /* build the ioctl and send it */
      bzero(&mci, sizeof(mci));
      mci.sub_ioctl = MDACIOCTL_SETMEMORYMAILBOX;
      /* set buffer addresses */
      mci.param.setmemorymailbox.command_mailbox_physaddr = 
  	sc->mly_mmbox_busaddr + offsetof(struct mly_mmbox, mmm_command);
      mci.param.setmemorymailbox.status_mailbox_physaddr = 
  	sc->mly_mmbox_busaddr + offsetof(struct mly_mmbox, mmm_status);
      mci.param.setmemorymailbox.health_buffer_physaddr = 
  	sc->mly_mmbox_busaddr + offsetof(struct mly_mmbox, mmm_health);
  
      /* set buffer sizes - abuse of data_size field is revolting */
      sp = (u_int8_t *)&mci.data_size;
      sp[0] = ((sizeof(union mly_command_packet) * MLY_MMBOX_COMMANDS) / 1024);
      sp[1] = (sizeof(union mly_status_packet) * MLY_MMBOX_STATUS) / 1024;
      mci.param.setmemorymailbox.health_buffer_size = sizeof(union mly_health_region) / 1024;
  
      debug(1, "memory mailbox at %p (0x%llx/%d 0x%llx/%d 0x%llx/%d", sc->mly_mmbox,
  	  mci.param.setmemorymailbox.command_mailbox_physaddr, sp[0],
  	  mci.param.setmemorymailbox.status_mailbox_physaddr, sp[1],
  	  mci.param.setmemorymailbox.health_buffer_physaddr, 
  	  mci.param.setmemorymailbox.health_buffer_size);
  
      if ((error = mly_ioctl(sc, &mci, NULL, 0, &status, NULL, NULL)))
  	return(error);
      if (status != 0)
  	return(EIO);
      sc->mly_state |= MLY_STATE_MMBOX_ACTIVE;
      debug(1, "memory mailbox active");
      return(0);
  }
  
  /********************************************************************************
   * Flush all pending I/O from the controller.
   */
  static int
  mly_flush(struct mly_softc *sc)
  {
      struct mly_command_ioctl	mci;
      u_int8_t			status;
      int				error;
  
      debug_called(1);
  
      /* build the ioctl */
      bzero(&mci, sizeof(mci));
      mci.sub_ioctl = MDACIOCTL_FLUSHDEVICEDATA;
      mci.param.deviceoperation.operation_device = MLY_OPDEVICE_PHYSICAL_CONTROLLER;
  
      /* pass it off to the controller */
      if ((error = mly_ioctl(sc, &mci, NULL, 0, &status, NULL, NULL)))
  	return(error);
  
      return((status == 0) ? 0 : EIO);
  }
  
  /********************************************************************************
   * Perform an ioctl command.
   *
   * If (data) is not NULL, the command requires data transfer.  If (*data) is NULL
   * the command requires data transfer from the controller, and we will allocate
   * a buffer for it.  If (*data) is not NULL, the command requires data transfer
   * to the controller.
   *
   * XXX passing in the whole ioctl structure is ugly.  Better ideas?
   *
   * XXX we don't even try to handle the case where datasize > 4k.  We should.
   */
  static int
  mly_ioctl(struct mly_softc *sc, struct mly_command_ioctl *ioctl, void **data, size_t datasize, 
  	  u_int8_t *status, void *sense_buffer, size_t *sense_length)
  {
      struct mly_command		*mc;
      struct mly_command_ioctl	*mci;
      int				error;
  
      debug_called(1);
      MLY_ASSERT_LOCKED(sc);
  
      mc = NULL;
      if (mly_alloc_command(sc, &mc)) {
  	error = ENOMEM;
  	goto out;
      }
  
      /* copy the ioctl structure, but save some important fields and then fixup */
      mci = &mc->mc_packet->ioctl;
      ioctl->sense_buffer_address = mci->sense_buffer_address;
      ioctl->maximum_sense_size = mci->maximum_sense_size;
      *mci = *ioctl;
      mci->opcode = MDACMD_IOCTL;
      mci->timeout.value = 30;
      mci->timeout.scale = MLY_TIMEOUT_SECONDS;
      
      /* handle the data buffer */
      if (data != NULL) {
  	if (*data == NULL) {
  	    /* allocate data buffer */
  	    if ((mc->mc_data = malloc(datasize, M_DEVBUF, M_NOWAIT)) == NULL) {
  		error = ENOMEM;
  		goto out;
  	    }
  	    mc->mc_flags |= MLY_CMD_DATAIN;
  	} else {
  	    mc->mc_data = *data;
  	    mc->mc_flags |= MLY_CMD_DATAOUT;
  	}
  	mc->mc_length = datasize;
  	mc->mc_packet->generic.data_size = datasize;
      }
      
      /* run the command */
      if ((error = mly_immediate_command(mc)))
  	goto out;
      
      /* clean up and return any data */
      *status = mc->mc_status;
      if ((mc->mc_sense > 0) && (sense_buffer != NULL)) {
  	bcopy(mc->mc_packet, sense_buffer, mc->mc_sense);
  	*sense_length = mc->mc_sense;
  	goto out;
      }
  
      /* should we return a data pointer? */
      if ((data != NULL) && (*data == NULL))
  	*data = mc->mc_data;
  
      /* command completed OK */
      error = 0;
  
  out:
      if (mc != NULL) {
  	/* do we need to free a data buffer we allocated? */
  	if (error && (mc->mc_data != NULL) && (*data == NULL))
  	    free(mc->mc_data, M_DEVBUF);
  	mly_release_command(mc);
      }
      return(error);
  }
  
  /********************************************************************************
   * Check for event(s) outstanding in the controller.
   */
  static void
  mly_check_event(struct mly_softc *sc)
  {
      
      /*
       * The controller may have updated the health status information,
       * so check for it here.  Note that the counters are all in host memory,
       * so this check is very cheap.  Also note that we depend on checking on
       * completion 
       */
      if (sc->mly_mmbox->mmm_health.status.change_counter != sc->mly_event_change) {
  	sc->mly_event_change = sc->mly_mmbox->mmm_health.status.change_counter;
  	debug(1, "event change %d, event status update, %d -> %d", sc->mly_event_change,
  	      sc->mly_event_waiting, sc->mly_mmbox->mmm_health.status.next_event);
  	sc->mly_event_waiting = sc->mly_mmbox->mmm_health.status.next_event;
  
  	/* wake up anyone that might be interested in this */
  	wakeup(&sc->mly_event_change);
      }
      if (sc->mly_event_counter != sc->mly_event_waiting)
      mly_fetch_event(sc);
  }
  
  /********************************************************************************
   * Fetch one event from the controller.
   *
   * If we fail due to resource starvation, we'll be retried the next time a 
   * command completes.
   */
  static void
  mly_fetch_event(struct mly_softc *sc)
  {
      struct mly_command		*mc;
      struct mly_command_ioctl	*mci;
      u_int32_t			event;
  
      debug_called(1);
  
      /* get a command */
      if (mly_alloc_command(sc, &mc))
  	return;
  
      /* set up the data buffer */
      if ((mc->mc_data = malloc(sizeof(struct mly_event), M_DEVBUF, M_NOWAIT | M_ZERO)) == NULL) {
  	mly_release_command(mc);
  	return;
      }
      mc->mc_length = sizeof(struct mly_event);
      mc->mc_flags |= MLY_CMD_DATAIN;
      mc->mc_complete = mly_complete_event;
  
      /*
       * Get an event number to fetch.  It's possible that we've raced with another
       * context for the last event, in which case there will be no more events.
       */
      if (sc->mly_event_counter == sc->mly_event_waiting) {
  	mly_release_command(mc);
  	return;
      }
      event = sc->mly_event_counter++;
  
      /* 
       * Build the ioctl.
       *
       * At this point we are committed to sending this request, as it
       * will be the only one constructed for this particular event number.
       */
      mci = (struct mly_command_ioctl *)&mc->mc_packet->ioctl;
      mci->opcode = MDACMD_IOCTL;
      mci->data_size = sizeof(struct mly_event);
      mci->addr.phys.lun = (event >> 16) & 0xff;
      mci->addr.phys.target = (event >> 24) & 0xff;
      mci->addr.phys.channel = 0;
      mci->addr.phys.controller = 0;
      mci->timeout.value = 30;
      mci->timeout.scale = MLY_TIMEOUT_SECONDS;
      mci->sub_ioctl = MDACIOCTL_GETEVENT;
      mci->param.getevent.sequence_number_low = event & 0xffff;
  
      debug(1, "fetch event %u", event);
  
      /*
       * Submit the command.
       *
       * Note that failure of mly_start() will result in this event never being
       * fetched.
       */
      if (mly_start(mc) != 0) {
  	mly_printf(sc, "couldn't fetch event %u\n", event);
  	mly_release_command(mc);
      }
  }
  
  /********************************************************************************
   * Handle the completion of an event poll.
   */
  static void
  mly_complete_event(struct mly_command *mc)
  {
      struct mly_softc	*sc = mc->mc_sc;
      struct mly_event	*me = (struct mly_event *)mc->mc_data;
  
      debug_called(1);
  
      /* 
       * If the event was successfully fetched, process it.
       */
      if (mc->mc_status == SCSI_STATUS_OK) {
  	mly_process_event(sc, me);
  	free(me, M_DEVBUF);
      }
      mly_release_command(mc);
  
      /*
       * Check for another event.
       */
      mly_check_event(sc);
  }
  
  /********************************************************************************
   * Process a controller event.
   */
  static void
  mly_process_event(struct mly_softc *sc, struct mly_event *me)
  {
      struct scsi_sense_data_fixed *ssd;
      char			 *fp, *tp;
      int				 bus, target, event, class, action;
  
      ssd = (struct scsi_sense_data_fixed *)&me->sense[0];
  
      /* 
       * Errors can be reported using vendor-unique sense data.  In this case, the
       * event code will be 0x1c (Request sense data present), the sense key will
       * be 0x09 (vendor specific), the MSB of the ASC will be set, and the 
       * actual event code will be a 16-bit value comprised of the ASCQ (low byte)
       * and low seven bits of the ASC (low seven bits of the high byte).
       */
      if ((me->code == 0x1c) && 
  	((ssd->flags & SSD_KEY) == SSD_KEY_Vendor_Specific) &&
  	(ssd->add_sense_code & 0x80)) {
  	event = ((int)(ssd->add_sense_code & ~0x80) << 8) + ssd->add_sense_code_qual;
      } else {
  	event = me->code;
      }
  
      /* look up event, get codes */
      fp = mly_describe_code(mly_table_event, event);
  
      debug(1, "Event %d  code 0x%x", me->sequence_number, me->code);
  
      /* quiet event? */
      class = fp[0];
      if (isupper(class) && bootverbose)
  	class = tolower(class);
  
      /* get action code, text string */
      action = fp[1];
      tp = &fp[2];
  
      /*
       * Print some information about the event.
       *
       * This code uses a table derived from the corresponding portion of the Linux
       * driver, and thus the parser is very similar.
       */
      switch(class) {
      case 'p':		/* error on physical device */
  	mly_printf(sc, "physical device %d:%d %s\n", me->channel, me->target, tp);
  	if (action == 'r')
  	    sc->mly_btl[me->channel][me->target].mb_flags |= MLY_BTL_RESCAN;
  	break;
      case 'l':		/* error on logical unit */
      case 'm':		/* message about logical unit */
  	bus = MLY_LOGDEV_BUS(sc, me->lun);
  	target = MLY_LOGDEV_TARGET(sc, me->lun);
  	mly_name_device(sc, bus, target);
  	mly_printf(sc, "logical device %d (%s) %s\n", me->lun, sc->mly_btl[bus][target].mb_name, tp);
  	if (action == 'r')
  	    sc->mly_btl[bus][target].mb_flags |= MLY_BTL_RESCAN;
  	break;
      case 's':		/* report of sense data */
  	if (((ssd->flags & SSD_KEY) == SSD_KEY_NO_SENSE) ||
  	    (((ssd->flags & SSD_KEY) == SSD_KEY_NOT_READY) && 
  	     (ssd->add_sense_code == 0x04) && 
  	     ((ssd->add_sense_code_qual == 0x01) || (ssd->add_sense_code_qual == 0x02))))
  	    break;	/* ignore NO_SENSE or NOT_READY in one case */
  
  	mly_printf(sc, "physical device %d:%d %s\n", me->channel, me->target, tp);
  	mly_printf(sc, "  sense key %d  asc %02x  ascq %02x\n", 
  		      ssd->flags & SSD_KEY, ssd->add_sense_code, ssd->add_sense_code_qual);
  	mly_printf(sc, "  info %4D  csi %4D\n", ssd->info, "", ssd->cmd_spec_info, "");
  	if (action == 'r')
  	    sc->mly_btl[me->channel][me->target].mb_flags |= MLY_BTL_RESCAN;
  	break;
      case 'e':
  	mly_printf(sc, tp, me->target, me->lun);
  	printf("\n");
  	break;
      case 'c':
  	mly_printf(sc, "controller %s\n", tp);
  	break;
      case '?':
  	mly_printf(sc, "%s - %d\n", tp, me->code);
  	break;
      default:	/* probably a 'noisy' event being ignored */
  	break;
      }
  }
  
  /********************************************************************************
   * Perform periodic activities.
   */
  static void
  mly_periodic(void *data)
  {
      struct mly_softc	*sc = (struct mly_softc *)data;
      int			bus, target;
  
      debug_called(2);
      MLY_ASSERT_LOCKED(sc);
  
      /*
       * Scan devices.
       */
      for (bus = 0; bus < sc->mly_cam_channels; bus++) {
  	if (MLY_BUS_IS_VALID(sc, bus)) {
  	    for (target = 0; target < MLY_MAX_TARGETS; target++) {
  
  		/* ignore the controller in this scan */
  		if (target == sc->mly_controllerparam->initiator_id)
  		    continue;
  
  		/* perform device rescan? */
  		if (sc->mly_btl[bus][target].mb_flags & MLY_BTL_RESCAN)
  		    mly_rescan_btl(sc, bus, target);
  	    }
  	}
      }
      
      /* check for controller events */
      mly_check_event(sc);
  
      /* reschedule ourselves */
      callout_schedule(&sc->mly_periodic, MLY_PERIODIC_INTERVAL * hz);
  }
  
  /********************************************************************************
   ********************************************************************************
                                                                 Command Processing
   ********************************************************************************
   ********************************************************************************/
  
  /********************************************************************************
   * Run a command and wait for it to complete.
   *
   */
  static int
  mly_immediate_command(struct mly_command *mc)
  {
      struct mly_softc	*sc = mc->mc_sc;
      int			error;
  
      debug_called(1);
  
      MLY_ASSERT_LOCKED(sc);
      if ((error = mly_start(mc))) {
  	return(error);
      }
  
      if (sc->mly_state & MLY_STATE_INTERRUPTS_ON) {
  	/* sleep on the command */
  	while(!(mc->mc_flags & MLY_CMD_COMPLETE)) {
  	    mtx_sleep(mc, &sc->mly_lock, PRIBIO, "mlywait", 0);
  	}
      } else {
  	/* spin and collect status while we do */
  	while(!(mc->mc_flags & MLY_CMD_COMPLETE)) {
  	    mly_done(mc->mc_sc);
  	}
      }
      return(0);
  }
  
  /********************************************************************************
   * Deliver a command to the controller.
   *
   * XXX it would be good to just queue commands that we can't submit immediately
   *     and send them later, but we probably want a wrapper for that so that
   *     we don't hang on a failed submission for an immediate command.
   */
  static int
  mly_start(struct mly_command *mc)
  {
      struct mly_softc		*sc = mc->mc_sc;
      union mly_command_packet	*pkt;
  
      debug_called(2);
      MLY_ASSERT_LOCKED(sc);
  
      /* 
       * Set the command up for delivery to the controller. 
       */
      mly_map_command(mc);
      mc->mc_packet->generic.command_id = mc->mc_slot;
  
  #ifdef MLY_DEBUG
      mc->mc_timestamp = time_second;
  #endif
  
      /*
       * Do we have to use the hardware mailbox?
       */
      if (!(sc->mly_state & MLY_STATE_MMBOX_ACTIVE)) {
  	/*
  	 * Check to see if the controller is ready for us.
  	 */
  	if (MLY_IDBR_TRUE(sc, MLY_HM_CMDSENT)) {
  	    return(EBUSY);
  	}
  	mc->mc_flags |= MLY_CMD_BUSY;
  	
  	/*
  	 * It's ready, send the command.
  	 */
  	MLY_SET_MBOX(sc, sc->mly_command_mailbox, &mc->mc_packetphys);
  	MLY_SET_REG(sc, sc->mly_idbr, MLY_HM_CMDSENT);
  
      } else {	/* use memory-mailbox mode */
  
  	pkt = &sc->mly_mmbox->mmm_command[sc->mly_mmbox_command_index];
  
  	/* check to see if the next index is free yet */
  	if (pkt->mmbox.flag != 0) {
  	    return(EBUSY);
  	}
  	mc->mc_flags |= MLY_CMD_BUSY;
  	
  	/* copy in new command */
  	bcopy(mc->mc_packet->mmbox.data, pkt->mmbox.data, sizeof(pkt->mmbox.data));
  	/* barrier to ensure completion of previous write before we write the flag */
  	bus_barrier(sc->mly_regs_resource, 0, 0, BUS_SPACE_BARRIER_WRITE);
  	/* copy flag last */
  	pkt->mmbox.flag = mc->mc_packet->mmbox.flag;
  	/* barrier to ensure completion of previous write before we notify the controller */
  	bus_barrier(sc->mly_regs_resource, 0, 0, BUS_SPACE_BARRIER_WRITE);
  
  	/* signal controller, update index */
  	MLY_SET_REG(sc, sc->mly_idbr, MLY_AM_CMDSENT);
  	sc->mly_mmbox_command_index = (sc->mly_mmbox_command_index + 1) % MLY_MMBOX_COMMANDS;
      }
  
      mly_enqueue_busy(mc);
      return(0);
  }
  
  /********************************************************************************
   * Pick up command status from the controller, schedule a completion event
   */
  static void
  mly_done(struct mly_softc *sc) 
  {
      struct mly_command		*mc;
      union mly_status_packet	*sp;
      u_int16_t			slot;
      int				worked;
  
      MLY_ASSERT_LOCKED(sc);
      worked = 0;
  
      /* pick up hardware-mailbox commands */
      if (MLY_ODBR_TRUE(sc, MLY_HM_STSREADY)) {
  	slot = MLY_GET_REG2(sc, sc->mly_status_mailbox);
  	if (slot < MLY_SLOT_MAX) {
  	    mc = &sc->mly_command[slot - MLY_SLOT_START];
  	    mc->mc_status = MLY_GET_REG(sc, sc->mly_status_mailbox + 2);
  	    mc->mc_sense = MLY_GET_REG(sc, sc->mly_status_mailbox + 3);
  	    mc->mc_resid = MLY_GET_REG4(sc, sc->mly_status_mailbox + 4);
  	    mly_remove_busy(mc);
  	    mc->mc_flags &= ~MLY_CMD_BUSY;
  	    mly_enqueue_complete(mc);
  	    worked = 1;
  	} else {
  	    /* slot 0xffff may mean "extremely bogus command" */
  	    mly_printf(sc, "got HM completion for illegal slot %u\n", slot);
  	}
  	/* unconditionally acknowledge status */
  	MLY_SET_REG(sc, sc->mly_odbr, MLY_HM_STSREADY);
  	MLY_SET_REG(sc, sc->mly_idbr, MLY_HM_STSACK);
      }
  
      /* pick up memory-mailbox commands */
      if (MLY_ODBR_TRUE(sc, MLY_AM_STSREADY)) {
  	for (;;) {
  	    sp = &sc->mly_mmbox->mmm_status[sc->mly_mmbox_status_index];
  
  	    /* check for more status */
  	    if (sp->mmbox.flag == 0)
  		break;
  
  	    /* get slot number */
  	    slot = sp->status.command_id;
  	    if (slot < MLY_SLOT_MAX) {
  		mc = &sc->mly_command[slot - MLY_SLOT_START];
  		mc->mc_status = sp->status.status;
  		mc->mc_sense = sp->status.sense_length;
  		mc->mc_resid = sp->status.residue;
  		mly_remove_busy(mc);
  		mc->mc_flags &= ~MLY_CMD_BUSY;
  		mly_enqueue_complete(mc);
  		worked = 1;
  	    } else {
  		/* slot 0xffff may mean "extremely bogus command" */
  		mly_printf(sc, "got AM completion for illegal slot %u at %d\n", 
  			   slot, sc->mly_mmbox_status_index);
  	    }
  
  	    /* clear and move to next index */
  	    sp->mmbox.flag = 0;
  	    sc->mly_mmbox_status_index = (sc->mly_mmbox_status_index + 1) % MLY_MMBOX_STATUS;
  	}
  	/* acknowledge that we have collected status value(s) */
  	MLY_SET_REG(sc, sc->mly_odbr, MLY_AM_STSREADY);
      }
  
      if (worked) {
  	if (sc->mly_state & MLY_STATE_INTERRUPTS_ON)
  	    taskqueue_enqueue(taskqueue_thread, &sc->mly_task_complete);
  	else
  	    mly_complete(sc);
      }
  }
  
  /********************************************************************************
   * Process completed commands
   */
  static void
  mly_complete_handler(void *context, int pending)
  {
      struct mly_softc	*sc = (struct mly_softc *)context;
  
      MLY_LOCK(sc);
      mly_complete(sc);
      MLY_UNLOCK(sc);
  }
  
  static void
  mly_complete(struct mly_softc *sc)
  {
      struct mly_command	*mc;
      void	        (* mc_complete)(struct mly_command *mc);
  
      debug_called(2);
  
      /* 
       * Spin pulling commands off the completed queue and processing them.
       */
      while ((mc = mly_dequeue_complete(sc)) != NULL) {
  
  	/*
  	 * Free controller resources, mark command complete.
  	 *
  	 * Note that as soon as we mark the command complete, it may be freed
  	 * out from under us, so we need to save the mc_complete field in
  	 * order to later avoid dereferencing mc.  (We would not expect to
  	 * have a polling/sleeping consumer with mc_complete != NULL).
  	 */
  	mly_unmap_command(mc);
  	mc_complete = mc->mc_complete;
  	mc->mc_flags |= MLY_CMD_COMPLETE;
  
  	/* 
  	 * Call completion handler or wake up sleeping consumer.
  	 */
  	if (mc_complete != NULL) {
  	    mc_complete(mc);
  	} else {
  	    wakeup(mc);
  	}
      }
      
      /*
       * XXX if we are deferring commands due to controller-busy status, we should
       *     retry submitting them here.
       */
  }
  
  /********************************************************************************
   ********************************************************************************
                                                          Command Buffer Management
   ********************************************************************************
   ********************************************************************************/
  
  /********************************************************************************
   * Allocate a command.
   */
  static int
  mly_alloc_command(struct mly_softc *sc, struct mly_command **mcp)
  {
      struct mly_command	*mc;
  
      debug_called(3);
  
      if ((mc = mly_dequeue_free(sc)) == NULL)
  	return(ENOMEM);
  
      *mcp = mc;
      return(0);
  }
  
  /********************************************************************************
   * Release a command back to the freelist.
   */
  static void
  mly_release_command(struct mly_command *mc)
  {
      debug_called(3);
  
      /*
       * Fill in parts of the command that may cause confusion if
       * a consumer doesn't when we are later allocated.
       */
      mc->mc_data = NULL;
      mc->mc_flags = 0;
      mc->mc_complete = NULL;
      mc->mc_private = NULL;
  
      /*
       * By default, we set up to overwrite the command packet with
       * sense information.
       */
      mc->mc_packet->generic.sense_buffer_address = mc->mc_packetphys;
      mc->mc_packet->generic.maximum_sense_size = sizeof(union mly_command_packet);
  
      mly_enqueue_free(mc);
  }
  
  /********************************************************************************
   * Map helper for command allocation.
   */
  static void
  mly_alloc_commands_map(void *arg, bus_dma_segment_t *segs, int nseg, int error)
  {
      struct mly_softc	*sc = (struct mly_softc *)arg;
  
      debug_called(1);
  
      sc->mly_packetphys = segs[0].ds_addr;
  }
  
  /********************************************************************************
   * Allocate and initialise command and packet structures.
   *
   * If the controller supports fewer than MLY_MAX_COMMANDS commands, limit our
   * allocation to that number.  If we don't yet know how many commands the
   * controller supports, allocate a very small set (suitable for initialisation
   * purposes only).
   */
  static int
  mly_alloc_commands(struct mly_softc *sc)
  {
      struct mly_command		*mc;
      int				i, ncmd;
   
      if (sc->mly_controllerinfo == NULL) {
  	ncmd = 4;
      } else {
  	ncmd = min(MLY_MAX_COMMANDS, sc->mly_controllerinfo->maximum_parallel_commands);
      }
  
      /*
       * Allocate enough space for all the command packets in one chunk and
       * map them permanently into controller-visible space.
       */
      if (bus_dmamem_alloc(sc->mly_packet_dmat, (void **)&sc->mly_packet, 
  			 BUS_DMA_NOWAIT, &sc->mly_packetmap)) {
  	return(ENOMEM);
      }
      if (bus_dmamap_load(sc->mly_packet_dmat, sc->mly_packetmap, sc->mly_packet, 
  			ncmd * sizeof(union mly_command_packet), 
  			mly_alloc_commands_map, sc, BUS_DMA_NOWAIT) != 0)
  	return (ENOMEM);
  
      for (i = 0; i < ncmd; i++) {
  	mc = &sc->mly_command[i];
  	bzero(mc, sizeof(*mc));
  	mc->mc_sc = sc;
  	mc->mc_slot = MLY_SLOT_START + i;
  	mc->mc_packet = sc->mly_packet + i;
  	mc->mc_packetphys = sc->mly_packetphys + (i * sizeof(union mly_command_packet));
  	if (!bus_dmamap_create(sc->mly_buffer_dmat, 0, &mc->mc_datamap))
  	    mly_release_command(mc);
      }
      return(0);
  }
  
  /********************************************************************************
   * Free all the storage held by commands.
   *
   * Must be called with all commands on the free list.
   */
  static void
  mly_release_commands(struct mly_softc *sc)
  {
      struct mly_command	*mc;
  
      /* throw away command buffer DMA maps */
      while (mly_alloc_command(sc, &mc) == 0)
  	bus_dmamap_destroy(sc->mly_buffer_dmat, mc->mc_datamap);
  
      /* release the packet storage */
      if (sc->mly_packet != NULL) {
  	bus_dmamap_unload(sc->mly_packet_dmat, sc->mly_packetmap);
  	bus_dmamem_free(sc->mly_packet_dmat, sc->mly_packet, sc->mly_packetmap);
  	sc->mly_packet = NULL;
      }
  }
  
  
  /********************************************************************************
   * Command-mapping helper function - populate this command's s/g table
   * with the s/g entries for its data.
   */
  static void
  mly_map_command_sg(void *arg, bus_dma_segment_t *segs, int nseg, int error)
  {
      struct mly_command		*mc = (struct mly_command *)arg;
      struct mly_softc		*sc = mc->mc_sc;
      struct mly_command_generic	*gen = &(mc->mc_packet->generic);
      struct mly_sg_entry		*sg;
      int				i, tabofs;
  
      debug_called(2);
  
      /* can we use the transfer structure directly? */
      if (nseg <= 2) {
  	sg = &gen->transfer.direct.sg[0];
  	gen->command_control.extended_sg_table = 0;
      } else {
  	tabofs = ((mc->mc_slot - MLY_SLOT_START) * MLY_MAX_SGENTRIES);
  	sg = sc->mly_sg_table + tabofs;
  	gen->transfer.indirect.entries[0] = nseg;
  	gen->transfer.indirect.table_physaddr[0] = sc->mly_sg_busaddr + (tabofs * sizeof(struct mly_sg_entry));
  	gen->command_control.extended_sg_table = 1;
      }
  
      /* copy the s/g table */
      for (i = 0; i < nseg; i++) {
  	sg[i].physaddr = segs[i].ds_addr;
  	sg[i].length = segs[i].ds_len;
      }
  
  }
  
  #if 0
  /********************************************************************************
   * Command-mapping helper function - save the cdb's physical address.
   *
   * We don't support 'large' SCSI commands at this time, so this is unused.
   */
  static void
  mly_map_command_cdb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
  {
      struct mly_command			*mc = (struct mly_command *)arg;
  
      debug_called(2);
  
      /* XXX can we safely assume that a CDB will never cross a page boundary? */
      if ((segs[0].ds_addr % PAGE_SIZE) > 
  	((segs[0].ds_addr + mc->mc_packet->scsi_large.cdb_length) % PAGE_SIZE))
  	panic("cdb crosses page boundary");
  
      /* fix up fields in the command packet */
      mc->mc_packet->scsi_large.cdb_physaddr = segs[0].ds_addr;
  }
  #endif
  
  /********************************************************************************
   * Map a command into controller-visible space
   */
  static void
  mly_map_command(struct mly_command *mc)
  {
      struct mly_softc	*sc = mc->mc_sc;
  
      debug_called(2);
  
      /* don't map more than once */
      if (mc->mc_flags & MLY_CMD_MAPPED)
  	return;
  
      /* does the command have a data buffer? */
      if (mc->mc_data != NULL) {
  	if (mc->mc_flags & MLY_CMD_CCB)
  		bus_dmamap_load_ccb(sc->mly_buffer_dmat, mc->mc_datamap,
  				mc->mc_data, mly_map_command_sg, mc, 0);
  	else 
  		bus_dmamap_load(sc->mly_buffer_dmat, mc->mc_datamap,
  				mc->mc_data, mc->mc_length, 
  				mly_map_command_sg, mc, 0);
  	if (mc->mc_flags & MLY_CMD_DATAIN)
  	    bus_dmamap_sync(sc->mly_buffer_dmat, mc->mc_datamap, BUS_DMASYNC_PREREAD);
  	if (mc->mc_flags & MLY_CMD_DATAOUT)
  	    bus_dmamap_sync(sc->mly_buffer_dmat, mc->mc_datamap, BUS_DMASYNC_PREWRITE);
      }
      mc->mc_flags |= MLY_CMD_MAPPED;
  }
  
  /********************************************************************************
   * Unmap a command from controller-visible space
   */
  static void
  mly_unmap_command(struct mly_command *mc)
  {
      struct mly_softc	*sc = mc->mc_sc;
  
      debug_called(2);
  
      if (!(mc->mc_flags & MLY_CMD_MAPPED))
  	return;
  
      /* does the command have a data buffer? */
      if (mc->mc_data != NULL) {
  	if (mc->mc_flags & MLY_CMD_DATAIN)
  	    bus_dmamap_sync(sc->mly_buffer_dmat, mc->mc_datamap, BUS_DMASYNC_POSTREAD);
  	if (mc->mc_flags & MLY_CMD_DATAOUT)
  	    bus_dmamap_sync(sc->mly_buffer_dmat, mc->mc_datamap, BUS_DMASYNC_POSTWRITE);
  
  	bus_dmamap_unload(sc->mly_buffer_dmat, mc->mc_datamap);
      }
      mc->mc_flags &= ~MLY_CMD_MAPPED;
  }
  
  
  /********************************************************************************
   ********************************************************************************
                                                                      CAM interface
   ********************************************************************************
   ********************************************************************************/
  
  /********************************************************************************
   * Attach the physical and virtual SCSI busses to CAM.
   *
   * Physical bus numbering starts from 0, virtual bus numbering from one greater
   * than the highest physical bus.  Physical busses are only registered if
   * the kernel environment variable "hw.mly.register_physical_channels" is set.
   *
   * When we refer to a "bus", we are referring to the bus number registered with
   * the SIM, whereas a "channel" is a channel number given to the adapter.  In order
   * to keep things simple, we map these 1:1, so "bus" and "channel" may be used
   * interchangeably.
   */
  static int
  mly_cam_attach(struct mly_softc *sc)
  {
      struct cam_devq	*devq;
      int			chn, i;
  
      debug_called(1);
  
      /*
       * Allocate a devq for all our channels combined.
       */
      if ((devq = cam_simq_alloc(sc->mly_controllerinfo->maximum_parallel_commands)) == NULL) {
  	mly_printf(sc, "can't allocate CAM SIM queue\n");
  	return(ENOMEM);
      }
  
      /*
       * If physical channel registration has been requested, register these first.
       * Note that we enable tagged command queueing for physical channels.
       */
      if (testenv("hw.mly.register_physical_channels")) {
  	chn = 0;
  	for (i = 0; i < sc->mly_controllerinfo->physical_channels_present; i++, chn++) {
  
  	    if ((sc->mly_cam_sim[chn] = cam_sim_alloc(mly_cam_action, mly_cam_poll, "mly", sc,
  						      device_get_unit(sc->mly_dev),
  						      &sc->mly_lock,
  						      sc->mly_controllerinfo->maximum_parallel_commands,
  						      1, devq)) == NULL) {
  		return(ENOMEM);
  	    }
  	    MLY_LOCK(sc);
  	    if (xpt_bus_register(sc->mly_cam_sim[chn], sc->mly_dev, chn)) {
  		MLY_UNLOCK(sc);
  		mly_printf(sc, "CAM XPT phsyical channel registration failed\n");
  		return(ENXIO);
  	    }
  	    MLY_UNLOCK(sc);
  	    debug(1, "registered physical channel %d", chn);
  	}
      }
  
      /*
       * Register our virtual channels, with bus numbers matching channel numbers.
       */
      chn = sc->mly_controllerinfo->physical_channels_present;
      for (i = 0; i < sc->mly_controllerinfo->virtual_channels_present; i++, chn++) {
  	if ((sc->mly_cam_sim[chn] = cam_sim_alloc(mly_cam_action, mly_cam_poll, "mly", sc,
  						  device_get_unit(sc->mly_dev),
  						  &sc->mly_lock,
  						  sc->mly_controllerinfo->maximum_parallel_commands,
  						  0, devq)) == NULL) {
  	    return(ENOMEM);
  	}
  	MLY_LOCK(sc);
  	if (xpt_bus_register(sc->mly_cam_sim[chn], sc->mly_dev, chn)) {
  	    MLY_UNLOCK(sc);
  	    mly_printf(sc, "CAM XPT virtual channel registration failed\n");
  	    return(ENXIO);
  	}
  	MLY_UNLOCK(sc);
  	debug(1, "registered virtual channel %d", chn);
      }
  
      /*
       * This is the total number of channels that (might have been) registered with
       * CAM.  Some may not have been; check the mly_cam_sim array to be certain.
       */
      sc->mly_cam_channels = sc->mly_controllerinfo->physical_channels_present +
  	sc->mly_controllerinfo->virtual_channels_present;
  
      return(0);
  }
  
  /********************************************************************************
   * Detach from CAM
   */
  static void
  mly_cam_detach(struct mly_softc *sc)
  {
      int		i;
      
      debug_called(1);
  
      MLY_LOCK(sc);
      for (i = 0; i < sc->mly_cam_channels; i++) {
  	if (sc->mly_cam_sim[i] != NULL) {
  	    xpt_bus_deregister(cam_sim_path(sc->mly_cam_sim[i]));
  	    cam_sim_free(sc->mly_cam_sim[i], 0);
  	}
      }
      MLY_UNLOCK(sc);
      if (sc->mly_cam_devq != NULL)
  	cam_simq_free(sc->mly_cam_devq);
  }
  
  /************************************************************************
   * Rescan a device.
   */ 
  static void
  mly_cam_rescan_btl(struct mly_softc *sc, int bus, int target)
  {
      union ccb	*ccb;
  
      debug_called(1);
  
      if ((ccb = xpt_alloc_ccb()) == NULL) {
  	mly_printf(sc, "rescan failed (can't allocate CCB)\n");
  	return;
      }
      if (xpt_create_path(&ccb->ccb_h.path, NULL,
  	    cam_sim_path(sc->mly_cam_sim[bus]), target, 0) != CAM_REQ_CMP) {
  	mly_printf(sc, "rescan failed (can't create path)\n");
  	xpt_free_ccb(ccb);
  	return;
      }
      debug(1, "rescan target %d:%d", bus, target);
      xpt_rescan(ccb);
  }
  
  /********************************************************************************
   * Handle an action requested by CAM
   */
  static void
  mly_cam_action(struct cam_sim *sim, union ccb *ccb)
  {
      struct mly_softc	*sc = cam_sim_softc(sim);
  
      debug_called(2);
      MLY_ASSERT_LOCKED(sc);
  
      switch (ccb->ccb_h.func_code) {
  
  	/* perform SCSI I/O */
      case XPT_SCSI_IO:
  	if (!mly_cam_action_io(sim, (struct ccb_scsiio *)&ccb->csio))
  	    return;
  	break;
  
  	/* perform geometry calculations */
      case XPT_CALC_GEOMETRY:
      {
  	struct ccb_calc_geometry	*ccg = &ccb->ccg;
          u_int32_t			secs_per_cylinder;
  
  	debug(2, "XPT_CALC_GEOMETRY %d:%d:%d", cam_sim_bus(sim), ccb->ccb_h.target_id, ccb->ccb_h.target_lun);
  
  	if (sc->mly_controllerparam->bios_geometry == MLY_BIOSGEOM_8G) {
  	    ccg->heads = 255;
              ccg->secs_per_track = 63;
  	} else {				/* MLY_BIOSGEOM_2G */
  	    ccg->heads = 128;
              ccg->secs_per_track = 32;
  	}
  	secs_per_cylinder = ccg->heads * ccg->secs_per_track;
          ccg->cylinders = ccg->volume_size / secs_per_cylinder;
          ccb->ccb_h.status = CAM_REQ_CMP;
          break;
      }
  
  	/* handle path attribute inquiry */
      case XPT_PATH_INQ:
      {
  	struct ccb_pathinq	*cpi = &ccb->cpi;
  
  	debug(2, "XPT_PATH_INQ %d:%d:%d", cam_sim_bus(sim), ccb->ccb_h.target_id, ccb->ccb_h.target_lun);
  
  	cpi->version_num = 1;
  	cpi->hba_inquiry = PI_TAG_ABLE;		/* XXX extra flags for physical channels? */
  	cpi->target_sprt = 0;
  	cpi->hba_misc = 0;
  	cpi->max_target = MLY_MAX_TARGETS - 1;
  	cpi->max_lun = MLY_MAX_LUNS - 1;
  	cpi->initiator_id = sc->mly_controllerparam->initiator_id;
  	strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
  	strlcpy(cpi->hba_vid, "Mylex", HBA_IDLEN);
  	strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
  	cpi->unit_number = cam_sim_unit(sim);
  	cpi->bus_id = cam_sim_bus(sim);
  	cpi->base_transfer_speed = 132 * 1024;	/* XXX what to set this to? */
  	cpi->transport = XPORT_SPI;
  	cpi->transport_version = 2;
  	cpi->protocol = PROTO_SCSI;
  	cpi->protocol_version = SCSI_REV_2;
  	ccb->ccb_h.status = CAM_REQ_CMP;
  	break;
      }
  
      case XPT_GET_TRAN_SETTINGS:
      {
  	struct ccb_trans_settings	*cts = &ccb->cts;
  	int				bus, target;
  	struct ccb_trans_settings_scsi *scsi = &cts->proto_specific.scsi;
  	struct ccb_trans_settings_spi *spi = &cts->xport_specific.spi;
  
  	cts->protocol = PROTO_SCSI;
  	cts->protocol_version = SCSI_REV_2;
  	cts->transport = XPORT_SPI;
  	cts->transport_version = 2;
  
  	scsi->flags = 0;
  	scsi->valid = 0;
  	spi->flags = 0;
  	spi->valid = 0;
  
  	bus = cam_sim_bus(sim);
  	target = cts->ccb_h.target_id;
  	debug(2, "XPT_GET_TRAN_SETTINGS %d:%d", bus, target);
  	/* logical device? */
  	if (sc->mly_btl[bus][target].mb_flags & MLY_BTL_LOGICAL) {
  	    /* nothing special for these */
  	/* physical device? */
  	} else if (sc->mly_btl[bus][target].mb_flags & MLY_BTL_PHYSICAL) {
  	    /* allow CAM to try tagged transactions */
  	    scsi->flags |= CTS_SCSI_FLAGS_TAG_ENB;
  	    scsi->valid |= CTS_SCSI_VALID_TQ;
  
  	    /* convert speed (MHz) to usec */
  	    if (sc->mly_btl[bus][target].mb_speed == 0) {
  		spi->sync_period = 1000000 / 5;
  	    } else {
  		spi->sync_period = 1000000 / sc->mly_btl[bus][target].mb_speed;
  	    }
  
  	    /* convert bus width to CAM internal encoding */
  	    switch (sc->mly_btl[bus][target].mb_width) {
  	    case 32:
  		spi->bus_width = MSG_EXT_WDTR_BUS_32_BIT;
  		break;
  	    case 16:
  		spi->bus_width = MSG_EXT_WDTR_BUS_16_BIT;
  		break;
  	    case 8:
  	    default:
  		spi->bus_width = MSG_EXT_WDTR_BUS_8_BIT;
  		break;
  	    }
  	    spi->valid |= CTS_SPI_VALID_SYNC_RATE | CTS_SPI_VALID_BUS_WIDTH;
  
  	    /* not a device, bail out */
  	} else {
  	    cts->ccb_h.status = CAM_REQ_CMP_ERR;
  	    break;
  	}
  
  	/* disconnect always OK */
  	spi->flags |= CTS_SPI_FLAGS_DISC_ENB;
  	spi->valid |= CTS_SPI_VALID_DISC;
  
  	cts->ccb_h.status = CAM_REQ_CMP;
  	break;
      }
  
      default:		/* we can't do this */
  	debug(2, "unspported func_code = 0x%x", ccb->ccb_h.func_code);
  	ccb->ccb_h.status = CAM_REQ_INVALID;
  	break;
      }
  
      xpt_done(ccb);
  }
  
  /********************************************************************************
   * Handle an I/O operation requested by CAM
   */
  static int
  mly_cam_action_io(struct cam_sim *sim, struct ccb_scsiio *csio)
  {
      struct mly_softc			*sc = cam_sim_softc(sim);
      struct mly_command			*mc;
      struct mly_command_scsi_small	*ss;
      int					bus, target;
      int					error;
  
      bus = cam_sim_bus(sim);
      target = csio->ccb_h.target_id;
  
      debug(2, "XPT_SCSI_IO %d:%d:%d", bus, target, csio->ccb_h.target_lun);
  
      /* validate bus number */
      if (!MLY_BUS_IS_VALID(sc, bus)) {
  	debug(0, " invalid bus %d", bus);
  	csio->ccb_h.status = CAM_REQ_CMP_ERR;
      }
  
      /*  check for I/O attempt to a protected device */
      if (sc->mly_btl[bus][target].mb_flags & MLY_BTL_PROTECTED) {
  	debug(2, "  device protected");
  	csio->ccb_h.status = CAM_REQ_CMP_ERR;
      }
  
      /* check for I/O attempt to nonexistent device */
      if (!(sc->mly_btl[bus][target].mb_flags & (MLY_BTL_LOGICAL | MLY_BTL_PHYSICAL))) {
  	debug(2, "  device %d:%d does not exist", bus, target);
  	csio->ccb_h.status = CAM_REQ_CMP_ERR;
      }
  
      /* XXX increase if/when we support large SCSI commands */
      if (csio->cdb_len > MLY_CMD_SCSI_SMALL_CDB) {
  	debug(0, "  command too large (%d > %d)", csio->cdb_len, MLY_CMD_SCSI_SMALL_CDB);
  	csio->ccb_h.status = CAM_REQ_CMP_ERR;
      }
  
      /* check that the CDB pointer is not to a physical address */
      if ((csio->ccb_h.flags & CAM_CDB_POINTER) && (csio->ccb_h.flags & CAM_CDB_PHYS)) {
  	debug(0, "  CDB pointer is to physical address");
  	csio->ccb_h.status = CAM_REQ_CMP_ERR;
      }
  
      /* abandon aborted ccbs or those that have failed validation */
      if ((csio->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_INPROG) {
  	debug(2, "abandoning CCB due to abort/validation failure");
  	return(EINVAL);
      }
  
      /*
       * Get a command, or push the ccb back to CAM and freeze the queue.
       */
      if ((error = mly_alloc_command(sc, &mc))) {
  	xpt_freeze_simq(sim, 1);
  	csio->ccb_h.status |= CAM_REQUEUE_REQ;
  	sc->mly_qfrzn_cnt++;
  	return(error);
      }
      
      /* build the command */
      mc->mc_data = csio;
      mc->mc_length = csio->dxfer_len;
      mc->mc_complete = mly_cam_complete;
      mc->mc_private = csio;
      mc->mc_flags |= MLY_CMD_CCB;
      /* XXX This code doesn't set the data direction in mc_flags. */
  
      /* save the bus number in the ccb for later recovery XXX should be a better way */
       csio->ccb_h.sim_priv.entries[0].field = bus;
  
      /* build the packet for the controller */
      ss = &mc->mc_packet->scsi_small;
      ss->opcode = MDACMD_SCSI;
      if (csio->ccb_h.flags & CAM_DIS_DISCONNECT)
  	ss->command_control.disable_disconnect = 1;
      if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT)
  	ss->command_control.data_direction = MLY_CCB_WRITE;
      ss->data_size = csio->dxfer_len;
      ss->addr.phys.lun = csio->ccb_h.target_lun;
      ss->addr.phys.target = csio->ccb_h.target_id;
      ss->addr.phys.channel = bus;
      if (csio->ccb_h.timeout < (60 * 1000)) {
  	ss->timeout.value = csio->ccb_h.timeout / 1000;
  	ss->timeout.scale = MLY_TIMEOUT_SECONDS;
      } else if (csio->ccb_h.timeout < (60 * 60 * 1000)) {
  	ss->timeout.value = csio->ccb_h.timeout / (60 * 1000);
  	ss->timeout.scale = MLY_TIMEOUT_MINUTES;
      } else {
  	ss->timeout.value = csio->ccb_h.timeout / (60 * 60 * 1000);	/* overflow? */
  	ss->timeout.scale = MLY_TIMEOUT_HOURS;
      }
      ss->maximum_sense_size = csio->sense_len;
      ss->cdb_length = csio->cdb_len;
      if (csio->ccb_h.flags & CAM_CDB_POINTER) {
  	bcopy(csio->cdb_io.cdb_ptr, ss->cdb, csio->cdb_len);
      } else {
  	bcopy(csio->cdb_io.cdb_bytes, ss->cdb, csio->cdb_len);
      }
  
      /* give the command to the controller */
      if ((error = mly_start(mc))) {
  	xpt_freeze_simq(sim, 1);
  	csio->ccb_h.status |= CAM_REQUEUE_REQ;
  	sc->mly_qfrzn_cnt++;
  	return(error);
      }
  
      return(0);
  }
  
  /********************************************************************************
   * Check for possibly-completed commands.
   */
  static void
  mly_cam_poll(struct cam_sim *sim)
  {
      struct mly_softc	*sc = cam_sim_softc(sim);
  
      debug_called(2);
  
      mly_done(sc);
  }
  
  /********************************************************************************
   * Handle completion of a command - pass results back through the CCB
   */
  static void
  mly_cam_complete(struct mly_command *mc)
  {
      struct mly_softc		*sc = mc->mc_sc;
      struct ccb_scsiio		*csio = (struct ccb_scsiio *)mc->mc_private;
      struct scsi_inquiry_data	*inq = (struct scsi_inquiry_data *)csio->data_ptr;
      struct mly_btl		*btl;
      u_int8_t			cmd;
      int				bus, target;
  
      debug_called(2);
  
      csio->scsi_status = mc->mc_status;
      switch(mc->mc_status) {
      case SCSI_STATUS_OK:
  	/*
  	 * In order to report logical device type and status, we overwrite
  	 * the result of the INQUIRY command to logical devices.
  	 */
  	bus = csio->ccb_h.sim_priv.entries[0].field;
  	target = csio->ccb_h.target_id;
  	/* XXX validate bus/target? */
  	if (sc->mly_btl[bus][target].mb_flags & MLY_BTL_LOGICAL) {
  	    if (csio->ccb_h.flags & CAM_CDB_POINTER) {
  		cmd = *csio->cdb_io.cdb_ptr;
  	    } else {
  		cmd = csio->cdb_io.cdb_bytes[0];
  	    }
  	    if (cmd == INQUIRY) {
  		btl = &sc->mly_btl[bus][target];
  		padstr(inq->vendor, mly_describe_code(mly_table_device_type, btl->mb_type), 8);
  		padstr(inq->product, mly_describe_code(mly_table_device_state, btl->mb_state), 16);
  		padstr(inq->revision, "", 4);
  	    }
  	}
  
  	debug(2, "SCSI_STATUS_OK");
  	csio->ccb_h.status = CAM_REQ_CMP;
  	break;
  
      case SCSI_STATUS_CHECK_COND:
  	debug(1, "SCSI_STATUS_CHECK_COND  sense %d  resid %d", mc->mc_sense, mc->mc_resid);
  	csio->ccb_h.status = CAM_SCSI_STATUS_ERROR;
  	bzero(&csio->sense_data, SSD_FULL_SIZE);
  	bcopy(mc->mc_packet, &csio->sense_data, mc->mc_sense);
  	csio->sense_len = mc->mc_sense;
  	csio->ccb_h.status |= CAM_AUTOSNS_VALID;
  	csio->resid = mc->mc_resid;	/* XXX this is a signed value... */
  	break;
  
      case SCSI_STATUS_BUSY:
  	debug(1, "SCSI_STATUS_BUSY");
  	csio->ccb_h.status = CAM_SCSI_BUSY;
  	break;
  
      default:
  	debug(1, "unknown status 0x%x", csio->scsi_status);
  	csio->ccb_h.status = CAM_REQ_CMP_ERR;
  	break;
      }
  
      if (sc->mly_qfrzn_cnt) {
  	csio->ccb_h.status |= CAM_RELEASE_SIMQ;
  	sc->mly_qfrzn_cnt--;
      }
  
      xpt_done((union ccb *)csio);
      mly_release_command(mc);
  }
  
  /********************************************************************************
   * Find a peripheral attahed at (bus),(target)
   */
  static struct cam_periph *
  mly_find_periph(struct mly_softc *sc, int bus, int target)
  {
      struct cam_periph	*periph;
      struct cam_path	*path;
      int			status;
  
      status = xpt_create_path(&path, NULL, cam_sim_path(sc->mly_cam_sim[bus]), target, 0);
      if (status == CAM_REQ_CMP) {
  	periph = cam_periph_find(path, NULL);
  	xpt_free_path(path);
      } else {
  	periph = NULL;
      }
      return(periph);
  }
  
  /********************************************************************************
   * Name the device at (bus)(target)
   */
  static int
  mly_name_device(struct mly_softc *sc, int bus, int target)
  {
      struct cam_periph	*periph;
  
      if ((periph = mly_find_periph(sc, bus, target)) != NULL) {
  	sprintf(sc->mly_btl[bus][target].mb_name, "%s%d", periph->periph_name, periph->unit_number);
  	return(0);
      }
      sc->mly_btl[bus][target].mb_name[0] = 0;
      return(ENOENT);
  }
  
  /********************************************************************************
   ********************************************************************************
                                                                   Hardware Control
   ********************************************************************************
   ********************************************************************************/
  
  /********************************************************************************
   * Handshake with the firmware while the card is being initialised.
   */
  static int
  mly_fwhandshake(struct mly_softc *sc) 
  {
      u_int8_t	error, param0, param1;
      int		spinup = 0;
  
      debug_called(1);
  
      /* set HM_STSACK and let the firmware initialise */
      MLY_SET_REG(sc, sc->mly_idbr, MLY_HM_STSACK);
      DELAY(1000);	/* too short? */
  
      /* if HM_STSACK is still true, the controller is initialising */
      if (!MLY_IDBR_TRUE(sc, MLY_HM_STSACK))
  	return(0);
      mly_printf(sc, "controller initialisation started\n");
  
      /* spin waiting for initialisation to finish, or for a message to be delivered */
      while (MLY_IDBR_TRUE(sc, MLY_HM_STSACK)) {
  	/* check for a message */
  	if (MLY_ERROR_VALID(sc)) {
  	    error = MLY_GET_REG(sc, sc->mly_error_status) & ~MLY_MSG_EMPTY;
  	    param0 = MLY_GET_REG(sc, sc->mly_command_mailbox);
  	    param1 = MLY_GET_REG(sc, sc->mly_command_mailbox + 1);
  
  	    switch(error) {
  	    case MLY_MSG_SPINUP:
  		if (!spinup) {
  		    mly_printf(sc, "drive spinup in progress\n");
  		    spinup = 1;			/* only print this once (should print drive being spun?) */
  		}
  		break;
  	    case MLY_MSG_RACE_RECOVERY_FAIL:
  		mly_printf(sc, "mirror race recovery failed, one or more drives offline\n");
  		break;
  	    case MLY_MSG_RACE_IN_PROGRESS:
  		mly_printf(sc, "mirror race recovery in progress\n");
  		break;
  	    case MLY_MSG_RACE_ON_CRITICAL:
  		mly_printf(sc, "mirror race recovery on a critical drive\n");
  		break;
  	    case MLY_MSG_PARITY_ERROR:
  		mly_printf(sc, "FATAL MEMORY PARITY ERROR\n");
  		return(ENXIO);
  	    default:
  		mly_printf(sc, "unknown initialisation code 0x%x\n", error);
  	    }
  	}
      }
      return(0);
  }
  
  /********************************************************************************
   ********************************************************************************
                                                          Debugging and Diagnostics
   ********************************************************************************
   ********************************************************************************/
  
  /********************************************************************************
   * Print some information about the controller.
   */
  static void
  mly_describe_controller(struct mly_softc *sc)
  {
      struct mly_ioctl_getcontrollerinfo	*mi = sc->mly_controllerinfo;
  
      mly_printf(sc, "%16s, %d channel%s, firmware %d.%02d-%d-%02d (%02d%02d%02d%02d), %dMB RAM\n", 
  	       mi->controller_name, mi->physical_channels_present, (mi->physical_channels_present) > 1 ? "s" : "",
  	       mi->fw_major, mi->fw_minor, mi->fw_turn, mi->fw_build,	/* XXX turn encoding? */
  	       mi->fw_century, mi->fw_year, mi->fw_month, mi->fw_day,
  	       mi->memory_size);
  
      if (bootverbose) {
  	mly_printf(sc, "%s %s (%x), %dMHz %d-bit %.16s\n", 
  		   mly_describe_code(mly_table_oemname, mi->oem_information), 
  		   mly_describe_code(mly_table_controllertype, mi->controller_type), mi->controller_type,
  		   mi->interface_speed, mi->interface_width, mi->interface_name);
  	mly_printf(sc, "%dMB %dMHz %d-bit %s%s%s, cache %dMB\n",
  		   mi->memory_size, mi->memory_speed, mi->memory_width, 
  		   mly_describe_code(mly_table_memorytype, mi->memory_type),
  		   mi->memory_parity ? "+parity": "",mi->memory_ecc ? "+ECC": "",
  		   mi->cache_size);
  	mly_printf(sc, "CPU: %s @ %dMHz\n", 
  		   mly_describe_code(mly_table_cputype, mi->cpu[0].type), mi->cpu[0].speed);
  	if (mi->l2cache_size != 0)
  	    mly_printf(sc, "%dKB L2 cache\n", mi->l2cache_size);
  	if (mi->exmemory_size != 0)
  	    mly_printf(sc, "%dMB %dMHz %d-bit private %s%s%s\n",
  		       mi->exmemory_size, mi->exmemory_speed, mi->exmemory_width,
  		       mly_describe_code(mly_table_memorytype, mi->exmemory_type),
  		       mi->exmemory_parity ? "+parity": "",mi->exmemory_ecc ? "+ECC": "");
  	mly_printf(sc, "battery backup %s\n", mi->bbu_present ? "present" : "not installed");
  	mly_printf(sc, "maximum data transfer %d blocks, maximum sg entries/command %d\n",
  		   mi->maximum_block_count, mi->maximum_sg_entries);
  	mly_printf(sc, "logical devices present/critical/offline %d/%d/%d\n",
  		   mi->logical_devices_present, mi->logical_devices_critical, mi->logical_devices_offline);
  	mly_printf(sc, "physical devices present %d\n",
  		   mi->physical_devices_present);
  	mly_printf(sc, "physical disks present/offline %d/%d\n",
  		   mi->physical_disks_present, mi->physical_disks_offline);
  	mly_printf(sc, "%d physical channel%s, %d virtual channel%s of %d possible\n",
  		   mi->physical_channels_present, mi->physical_channels_present == 1 ? "" : "s",
  		   mi->virtual_channels_present, mi->virtual_channels_present == 1 ? "" : "s",
  		   mi->virtual_channels_possible);
  	mly_printf(sc, "%d parallel commands supported\n", mi->maximum_parallel_commands);
  	mly_printf(sc, "%dMB flash ROM, %d of %d maximum cycles\n",
  		   mi->flash_size, mi->flash_age, mi->flash_maximum_age);
      }
  }
  
  #ifdef MLY_DEBUG
  /********************************************************************************
   * Print some controller state
   */
  static void
  mly_printstate(struct mly_softc *sc)
  {
      mly_printf(sc, "IDBR %02x  ODBR %02x  ERROR %02x  (%x %x %x)\n",
  		  MLY_GET_REG(sc, sc->mly_idbr),
  		  MLY_GET_REG(sc, sc->mly_odbr),
  		  MLY_GET_REG(sc, sc->mly_error_status),
  		  sc->mly_idbr,
  		  sc->mly_odbr,
  		  sc->mly_error_status);
      mly_printf(sc, "IMASK %02x  ISTATUS %02x\n",
  		  MLY_GET_REG(sc, sc->mly_interrupt_mask),
  		  MLY_GET_REG(sc, sc->mly_interrupt_status));
      mly_printf(sc, "COMMAND %02x %02x %02x %02x %02x %02x %02x %02x\n",
  		  MLY_GET_REG(sc, sc->mly_command_mailbox),
  		  MLY_GET_REG(sc, sc->mly_command_mailbox + 1),
  		  MLY_GET_REG(sc, sc->mly_command_mailbox + 2),
  		  MLY_GET_REG(sc, sc->mly_command_mailbox + 3),
  		  MLY_GET_REG(sc, sc->mly_command_mailbox + 4),
  		  MLY_GET_REG(sc, sc->mly_command_mailbox + 5),
  		  MLY_GET_REG(sc, sc->mly_command_mailbox + 6),
  		  MLY_GET_REG(sc, sc->mly_command_mailbox + 7));
      mly_printf(sc, "STATUS  %02x %02x %02x %02x %02x %02x %02x %02x\n",
  		  MLY_GET_REG(sc, sc->mly_status_mailbox),
  		  MLY_GET_REG(sc, sc->mly_status_mailbox + 1),
  		  MLY_GET_REG(sc, sc->mly_status_mailbox + 2),
  		  MLY_GET_REG(sc, sc->mly_status_mailbox + 3),
  		  MLY_GET_REG(sc, sc->mly_status_mailbox + 4),
  		  MLY_GET_REG(sc, sc->mly_status_mailbox + 5),
  		  MLY_GET_REG(sc, sc->mly_status_mailbox + 6),
  		  MLY_GET_REG(sc, sc->mly_status_mailbox + 7));
      mly_printf(sc, "        %04x        %08x\n",
  		  MLY_GET_REG2(sc, sc->mly_status_mailbox),
  		  MLY_GET_REG4(sc, sc->mly_status_mailbox + 4));
  }
  
  struct mly_softc	*mly_softc0 = NULL;
  void
  mly_printstate0(void)
  {
      if (mly_softc0 != NULL)
  	mly_printstate(mly_softc0);
  }
  
  /********************************************************************************
   * Print a command
   */
  static void
  mly_print_command(struct mly_command *mc)
  {
      struct mly_softc	*sc = mc->mc_sc;
      
      mly_printf(sc, "COMMAND @ %p\n", mc);
      mly_printf(sc, "  slot      %d\n", mc->mc_slot);
      mly_printf(sc, "  status    0x%x\n", mc->mc_status);
      mly_printf(sc, "  sense len %d\n", mc->mc_sense);
      mly_printf(sc, "  resid     %d\n", mc->mc_resid);
      mly_printf(sc, "  packet    %p/0x%llx\n", mc->mc_packet, mc->mc_packetphys);
      if (mc->mc_packet != NULL)
  	mly_print_packet(mc);
      mly_printf(sc, "  data      %p/%d\n", mc->mc_data, mc->mc_length);
      mly_printf(sc, "  flags     %b\n", mc->mc_flags, "\20\1busy\2complete\3slotted\4mapped\5datain\6dataout\n");
      mly_printf(sc, "  complete  %p\n", mc->mc_complete);
      mly_printf(sc, "  private   %p\n", mc->mc_private);
  }
  
  /********************************************************************************
   * Print a command packet
   */
  static void
  mly_print_packet(struct mly_command *mc)
  {
      struct mly_softc			*sc = mc->mc_sc;
      struct mly_command_generic		*ge = (struct mly_command_generic *)mc->mc_packet;
      struct mly_command_scsi_small	*ss = (struct mly_command_scsi_small *)mc->mc_packet;
      struct mly_command_scsi_large	*sl = (struct mly_command_scsi_large *)mc->mc_packet;
      struct mly_command_ioctl		*io = (struct mly_command_ioctl *)mc->mc_packet;
      int					transfer;
  
      mly_printf(sc, "   command_id           %d\n", ge->command_id);
      mly_printf(sc, "   opcode               %d\n", ge->opcode);
      mly_printf(sc, "   command_control      fua %d  dpo %d  est %d  dd %s  nas %d ddis %d\n",
  		  ge->command_control.force_unit_access,
  		  ge->command_control.disable_page_out,
  		  ge->command_control.extended_sg_table,
  		  (ge->command_control.data_direction == MLY_CCB_WRITE) ? "WRITE" : "READ",
  		  ge->command_control.no_auto_sense,
  		  ge->command_control.disable_disconnect);
      mly_printf(sc, "   data_size            %d\n", ge->data_size);
      mly_printf(sc, "   sense_buffer_address 0x%llx\n", ge->sense_buffer_address);
      mly_printf(sc, "   lun                  %d\n", ge->addr.phys.lun);
      mly_printf(sc, "   target               %d\n", ge->addr.phys.target);
      mly_printf(sc, "   channel              %d\n", ge->addr.phys.channel);
      mly_printf(sc, "   logical device       %d\n", ge->addr.log.logdev);
      mly_printf(sc, "   controller           %d\n", ge->addr.phys.controller);
      mly_printf(sc, "   timeout              %d %s\n", 
  		  ge->timeout.value,
  		  (ge->timeout.scale == MLY_TIMEOUT_SECONDS) ? "seconds" : 
  		  ((ge->timeout.scale == MLY_TIMEOUT_MINUTES) ? "minutes" : "hours"));
      mly_printf(sc, "   maximum_sense_size   %d\n", ge->maximum_sense_size);
      switch(ge->opcode) {
      case MDACMD_SCSIPT:
      case MDACMD_SCSI:
  	mly_printf(sc, "   cdb length           %d\n", ss->cdb_length);
  	mly_printf(sc, "   cdb                  %*D\n", ss->cdb_length, ss->cdb, " ");
  	transfer = 1;
  	break;
      case MDACMD_SCSILC:
      case MDACMD_SCSILCPT:
  	mly_printf(sc, "   cdb length           %d\n", sl->cdb_length);
  	mly_printf(sc, "   cdb                  0x%llx\n", sl->cdb_physaddr);
  	transfer = 1;
  	break;
      case MDACMD_IOCTL:
  	mly_printf(sc, "   sub_ioctl            0x%x\n", io->sub_ioctl);
  	switch(io->sub_ioctl) {
  	case MDACIOCTL_SETMEMORYMAILBOX:
  	    mly_printf(sc, "   health_buffer_size   %d\n", 
  			  io->param.setmemorymailbox.health_buffer_size);
  	    mly_printf(sc, "   health_buffer_phys   0x%llx\n",
  			  io->param.setmemorymailbox.health_buffer_physaddr);
  	    mly_printf(sc, "   command_mailbox      0x%llx\n",
  			  io->param.setmemorymailbox.command_mailbox_physaddr);
  	    mly_printf(sc, "   status_mailbox       0x%llx\n",
  			  io->param.setmemorymailbox.status_mailbox_physaddr);
  	    transfer = 0;
  	    break;
  
  	case MDACIOCTL_SETREALTIMECLOCK:
  	case MDACIOCTL_GETHEALTHSTATUS:
  	case MDACIOCTL_GETCONTROLLERINFO:
  	case MDACIOCTL_GETLOGDEVINFOVALID:
  	case MDACIOCTL_GETPHYSDEVINFOVALID:
  	case MDACIOCTL_GETPHYSDEVSTATISTICS:
  	case MDACIOCTL_GETLOGDEVSTATISTICS:
  	case MDACIOCTL_GETCONTROLLERSTATISTICS:
  	case MDACIOCTL_GETBDT_FOR_SYSDRIVE:	    
  	case MDACIOCTL_CREATENEWCONF:
  	case MDACIOCTL_ADDNEWCONF:
  	case MDACIOCTL_GETDEVCONFINFO:
  	case MDACIOCTL_GETFREESPACELIST:
  	case MDACIOCTL_MORE:
  	case MDACIOCTL_SETPHYSDEVPARAMETER:
  	case MDACIOCTL_GETPHYSDEVPARAMETER:
  	case MDACIOCTL_GETLOGDEVPARAMETER:
  	case MDACIOCTL_SETLOGDEVPARAMETER:
  	    mly_printf(sc, "   param                %10D\n", io->param.data.param, " ");
  	    transfer = 1;
  	    break;
  
  	case MDACIOCTL_GETEVENT:
  	    mly_printf(sc, "   event                %d\n", 
  		       io->param.getevent.sequence_number_low + ((u_int32_t)io->addr.log.logdev << 16));
  	    transfer = 1;
  	    break;
  
  	case MDACIOCTL_SETRAIDDEVSTATE:
  	    mly_printf(sc, "   state                %d\n", io->param.setraiddevstate.state);
  	    transfer = 0;
  	    break;
  
  	case MDACIOCTL_XLATEPHYSDEVTORAIDDEV:
  	    mly_printf(sc, "   raid_device          %d\n", io->param.xlatephysdevtoraiddev.raid_device);
  	    mly_printf(sc, "   controller           %d\n", io->param.xlatephysdevtoraiddev.controller);
  	    mly_printf(sc, "   channel              %d\n", io->param.xlatephysdevtoraiddev.channel);
  	    mly_printf(sc, "   target               %d\n", io->param.xlatephysdevtoraiddev.target);
  	    mly_printf(sc, "   lun                  %d\n", io->param.xlatephysdevtoraiddev.lun);
  	    transfer = 0;
  	    break;
  
  	case MDACIOCTL_GETGROUPCONFINFO:
  	    mly_printf(sc, "   group                %d\n", io->param.getgroupconfinfo.group);
  	    transfer = 1;
  	    break;
  
  	case MDACIOCTL_GET_SUBSYSTEM_DATA:
  	case MDACIOCTL_SET_SUBSYSTEM_DATA:
  	case MDACIOCTL_STARTDISOCVERY:
  	case MDACIOCTL_INITPHYSDEVSTART:
  	case MDACIOCTL_INITPHYSDEVSTOP:
  	case MDACIOCTL_INITRAIDDEVSTART:
  	case MDACIOCTL_INITRAIDDEVSTOP:
  	case MDACIOCTL_REBUILDRAIDDEVSTART:
  	case MDACIOCTL_REBUILDRAIDDEVSTOP:
  	case MDACIOCTL_MAKECONSISTENTDATASTART:
  	case MDACIOCTL_MAKECONSISTENTDATASTOP:
  	case MDACIOCTL_CONSISTENCYCHECKSTART:
  	case MDACIOCTL_CONSISTENCYCHECKSTOP:
  	case MDACIOCTL_RESETDEVICE:
  	case MDACIOCTL_FLUSHDEVICEDATA:
  	case MDACIOCTL_PAUSEDEVICE:
  	case MDACIOCTL_UNPAUSEDEVICE:
  	case MDACIOCTL_LOCATEDEVICE:
  	case MDACIOCTL_SETMASTERSLAVEMODE:
  	case MDACIOCTL_DELETERAIDDEV:
  	case MDACIOCTL_REPLACEINTERNALDEV:
  	case MDACIOCTL_CLEARCONF:
  	case MDACIOCTL_GETCONTROLLERPARAMETER:
  	case MDACIOCTL_SETCONTRLLERPARAMETER:
  	case MDACIOCTL_CLEARCONFSUSPMODE:
  	case MDACIOCTL_STOREIMAGE:
  	case MDACIOCTL_READIMAGE:
  	case MDACIOCTL_FLASHIMAGES:
  	case MDACIOCTL_RENAMERAIDDEV:
  	default:			/* no idea what to print */
  	    transfer = 0;
  	    break;
  	}
  	break;
  
      case MDACMD_IOCTLCHECK:
      case MDACMD_MEMCOPY:
      default:
  	transfer = 0;
  	break;	/* print nothing */
      }
      if (transfer) {
  	if (ge->command_control.extended_sg_table) {
  	    mly_printf(sc, "   sg table             0x%llx/%d\n",
  			  ge->transfer.indirect.table_physaddr[0], ge->transfer.indirect.entries[0]);
  	} else {
  	    mly_printf(sc, "   0000                 0x%llx/%lld\n",
  			  ge->transfer.direct.sg[0].physaddr, ge->transfer.direct.sg[0].length);
  	    mly_printf(sc, "   0001                 0x%llx/%lld\n",
  			  ge->transfer.direct.sg[1].physaddr, ge->transfer.direct.sg[1].length);
  	}
      }
  }
  
  /********************************************************************************
   * Panic in a slightly informative fashion
   */
  static void
  mly_panic(struct mly_softc *sc, char *reason)
  {
      mly_printstate(sc);
      panic(reason);
  }
  
  /********************************************************************************
   * Print queue statistics, callable from DDB.
   */
  void
  mly_print_controller(int controller)
  {
      struct mly_softc	*sc;
      
      if ((sc = devclass_get_softc(devclass_find("mly"), controller)) == NULL) {
  	printf("mly: controller %d invalid\n", controller);
      } else {
  	device_printf(sc->mly_dev, "queue    curr max\n");
  	device_printf(sc->mly_dev, "free     %04d/%04d\n", 
  		      sc->mly_qstat[MLYQ_FREE].q_length, sc->mly_qstat[MLYQ_FREE].q_max);
  	device_printf(sc->mly_dev, "busy     %04d/%04d\n", 
  		      sc->mly_qstat[MLYQ_BUSY].q_length, sc->mly_qstat[MLYQ_BUSY].q_max);
  	device_printf(sc->mly_dev, "complete %04d/%04d\n", 
  		      sc->mly_qstat[MLYQ_COMPLETE].q_length, sc->mly_qstat[MLYQ_COMPLETE].q_max);
      }
  }
  #endif
  
  
  /********************************************************************************
   ********************************************************************************
                                                           Control device interface
   ********************************************************************************
   ********************************************************************************/
  
  /********************************************************************************
   * Accept an open operation on the control device.
   */
  static int
  mly_user_open(struct cdev *dev, int flags, int fmt, struct thread *td)
  {
      struct mly_softc	*sc = dev->si_drv1;
  
      MLY_LOCK(sc);
      sc->mly_state |= MLY_STATE_OPEN;
      MLY_UNLOCK(sc);
      return(0);
  }
  
  /********************************************************************************
   * Accept the last close on the control device.
   */
  static int
  mly_user_close(struct cdev *dev, int flags, int fmt, struct thread *td)
  {
      struct mly_softc	*sc = dev->si_drv1;
  
      MLY_LOCK(sc);
      sc->mly_state &= ~MLY_STATE_OPEN;
      MLY_UNLOCK(sc);
      return (0);
  }
  
  /********************************************************************************
   * Handle controller-specific control operations.
   */
  static int
  mly_user_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
  				int32_t flag, struct thread *td)
  {
      struct mly_softc		*sc = (struct mly_softc *)dev->si_drv1;
      struct mly_user_command	*uc = (struct mly_user_command *)addr;
      struct mly_user_health	*uh = (struct mly_user_health *)addr;
      
      switch(cmd) {
      case MLYIO_COMMAND:
  	return(mly_user_command(sc, uc));
      case MLYIO_HEALTH:
  	return(mly_user_health(sc, uh));
      default:
  	return(ENOIOCTL);
      }
  }
  
  /********************************************************************************
   * Execute a command passed in from userspace.
   *
   * The control structure contains the actual command for the controller, as well
   * as the user-space data pointer and data size, and an optional sense buffer
   * size/pointer.  On completion, the data size is adjusted to the command
   * residual, and the sense buffer size to the size of the returned sense data.
   * 
   */
  static int
  mly_user_command(struct mly_softc *sc, struct mly_user_command *uc)
  {
      struct mly_command	*mc;
      int			error;
  
      /* allocate a command */
      MLY_LOCK(sc);
      if (mly_alloc_command(sc, &mc)) {
  	MLY_UNLOCK(sc);
  	return (ENOMEM);	/* XXX Linux version will wait for a command */
      }
      MLY_UNLOCK(sc);
  
      /* handle data size/direction */
      mc->mc_length = (uc->DataTransferLength >= 0) ? uc->DataTransferLength : -uc->DataTransferLength;
      if (mc->mc_length > 0) {
  	if ((mc->mc_data = malloc(mc->mc_length, M_DEVBUF, M_NOWAIT)) == NULL) {
  	    error = ENOMEM;
  	    goto out;
  	}
      }
      if (uc->DataTransferLength > 0) {
  	mc->mc_flags |= MLY_CMD_DATAIN;
  	bzero(mc->mc_data, mc->mc_length);
      }
      if (uc->DataTransferLength < 0) {
  	mc->mc_flags |= MLY_CMD_DATAOUT;
  	if ((error = copyin(uc->DataTransferBuffer, mc->mc_data, mc->mc_length)) != 0)
  	    goto out;
      }
  
      /* copy the controller command */
      bcopy(&uc->CommandMailbox, mc->mc_packet, sizeof(uc->CommandMailbox));
  
      /* clear command completion handler so that we get woken up */
      mc->mc_complete = NULL;
  
      /* execute the command */
      MLY_LOCK(sc);
      if ((error = mly_start(mc)) != 0) {
  	MLY_UNLOCK(sc);
  	goto out;
      }
      while (!(mc->mc_flags & MLY_CMD_COMPLETE))
  	mtx_sleep(mc, &sc->mly_lock, PRIBIO, "mlyioctl", 0);
      MLY_UNLOCK(sc);
  
      /* return the data to userspace */
      if (uc->DataTransferLength > 0)
  	if ((error = copyout(mc->mc_data, uc->DataTransferBuffer, mc->mc_length)) != 0)
  	    goto out;
      
      /* return the sense buffer to userspace */
      if ((uc->RequestSenseLength > 0) && (mc->mc_sense > 0)) {
  	if ((error = copyout(mc->mc_packet, uc->RequestSenseBuffer, 
  			     min(uc->RequestSenseLength, mc->mc_sense))) != 0)
  	    goto out;
      }
      
      /* return command results to userspace (caller will copy out) */
      uc->DataTransferLength = mc->mc_resid;
      uc->RequestSenseLength = min(uc->RequestSenseLength, mc->mc_sense);
      uc->CommandStatus = mc->mc_status;
      error = 0;
  
   out:
      if (mc->mc_data != NULL)
  	free(mc->mc_data, M_DEVBUF);
      MLY_LOCK(sc);
      mly_release_command(mc);
      MLY_UNLOCK(sc);
      return(error);
  }
  
  /********************************************************************************
   * Return health status to userspace.  If the health change index in the user
   * structure does not match that currently exported by the controller, we
   * return the current status immediately.  Otherwise, we block until either
   * interrupted or new status is delivered.
   */
  static int
  mly_user_health(struct mly_softc *sc, struct mly_user_health *uh)
  {
      struct mly_health_status		mh;
      int					error;
      
      /* fetch the current health status from userspace */
      if ((error = copyin(uh->HealthStatusBuffer, &mh, sizeof(mh))) != 0)
  	return(error);
  
      /* spin waiting for a status update */
      MLY_LOCK(sc);
      error = EWOULDBLOCK;
      while ((error != 0) && (sc->mly_event_change == mh.change_counter))
  	error = mtx_sleep(&sc->mly_event_change, &sc->mly_lock, PRIBIO | PCATCH,
  	    "mlyhealth", 0);
      mh = sc->mly_mmbox->mmm_health.status;
      MLY_UNLOCK(sc);
      
      /* copy the controller's health status buffer out */
      error = copyout(&mh, uh->HealthStatusBuffer, sizeof(mh));
      return(error);
  }
  
  #ifdef MLY_DEBUG
  static void
  mly_timeout(void *arg)
  {
  	struct mly_softc *sc;
  	struct mly_command *mc;
  	int deadline;
  
  	sc = arg;
  	MLY_ASSERT_LOCKED(sc);
  	deadline = time_second - MLY_CMD_TIMEOUT;
  	TAILQ_FOREACH(mc, &sc->mly_busy, mc_link) {
  		if ((mc->mc_timestamp < deadline)) {
  			device_printf(sc->mly_dev,
  			    "COMMAND %p TIMEOUT AFTER %d SECONDS\n", mc,
  			    (int)(time_second - mc->mc_timestamp));
  		}
  	}
  
  	callout_reset(&sc->mly_timeout, MLY_CMD_TIMEOUT * hz, mly_timeout, sc);
  }
  #endif
  