FreeBSD/Linux Kernel Cross Reference
sys/dev/mly/mly.c

     /*-
      * 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: releng/8.4/sys/dev/mly/mly.c 233025 2012-03-16 09:22:59Z scottl $
     */
    
    #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(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);
   #endif
   void            mly_print_controller(int controller);
   static int      mly_timeout(struct mly_softc *sc);
   
   
   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_flags =      D_NEEDGIANT,
           .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;
   
   #ifdef MLY_DEBUG
       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, 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
        */
       if ((error = mly_get_controllerinfo(sc)))
           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.
        */
       if ((error = mly_get_eventstatus(sc)))
           goto out;
   
       /*
        * Enable memory-mailbox mode.
        */
       if ((error = mly_enable_mmbox(sc)))
           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_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);
   
       /*
        * 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
       timeout((timeout_t *)mly_timeout, sc, MLY_CMD_TIMEOUT * hz);
   #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;
       u_int32_t           command;
   
       debug_called(1);
   
       /* assume failure is 'not configured' */
       error = ENXIO;
   
       /* 
        * Verify that the adapter is correctly set up in PCI space.
        * 
        * XXX we shouldn't do this; the PCI code should.
        */
       command = pci_read_config(sc->mly_dev, PCIR_COMMAND, 2);
       command |= PCIM_CMD_BUSMASTEREN;
       pci_write_config(sc->mly_dev, PCIR_COMMAND, command, 2);
       command = pci_read_config(sc->mly_dev, PCIR_COMMAND, 2);
       if (!(command & PCIM_CMD_BUSMASTEREN)) {
           mly_printf(sc, "can't enable busmaster feature\n");
           goto fail;
       }
       if ((command & PCIM_CMD_MEMEN) == 0) {
           mly_printf(sc, "memory window not available\n");
           goto fail;
       }
   
       /*
        * 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;
       }
       sc->mly_btag = rman_get_bustag(sc->mly_regs_resource);
       sc->mly_bhandle = rman_get_bushandle(sc->mly_regs_resource);
   
       /* 
        * 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, 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 */
                              MAXBSIZE, MLY_MAX_SGENTRIES, /* maxsize, 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 */
                              MAXBSIZE, MLY_MAX_SGENTRIES, /* maxsize, nsegments */
                              BUS_SPACE_MAXSIZE_32BIT,     /* maxsegsize */
                              0,                           /* flags */
                              busdma_lock_mutex,           /* lockfunc */
                              &Giant,                      /* 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);
       
       if (sc->mly_state & MLY_STATE_OPEN)
           return(EBUSY);
   
       /* kill the periodic event */
       untimeout(mly_periodic, sc, sc->mly_periodic);
   
       /* flush controller */
       mly_printf(sc, "flushing cache...");
       printf("%s\n", mly_flush(sc) ? "failed" : "done");
   
       MLY_MASK_INTERRUPTS(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_done(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);
   
       /* 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_intr)
           bus_teardown_intr(sc->mly_dev, sc->mly_irq, sc->mly_intr);
       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);
   }
   
   /********************************************************************************
    ********************************************************************************
                                                                    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);
  
      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;
      int                         s;
      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.
       */
      s = splcam();
      if (sc->mly_event_counter == sc->mly_event_waiting) {
          mly_release_command(mc);
          splx(s);
          return;
      }
      event = sc->mly_event_counter++;
      splx(s);
  
      /* 
       * 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      *ssd = (struct scsi_sense_data *)&me->sense[0];
      char                        *fp, *tp;
      int                         bus, target, event, class, action;
  
      /* 
       * 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;
        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);
  
      /*
       * 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 */
      sc->mly_periodic = timeout(mly_periodic, sc, 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, s;
  
      debug_called(1);
  
      /* spinning at splcam is ugly, but we're only used during controller init */
      s = splcam();
      if ((error = mly_start(mc))) {
          splx(s);
          return(error);
      }
  
      if (sc->mly_state & MLY_STATE_INTERRUPTS_ON) {
          /* sleep on the command */
          while(!(mc->mc_flags & MLY_CMD_COMPLETE)) {
              tsleep(mc, PRIBIO, "mlywait", 0);
          }
      } else {
          /* spin and collect status while we do */
          while(!(mc->mc_flags & MLY_CMD_COMPLETE)) {
              mly_done(mc->mc_sc);
          }
      }
      splx(s);
      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;
      int                         s;
  
      debug_called(2);
  
      /* 
       * 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
  
      s = splcam();
  
      /*
       * 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)) {
              splx(s);
              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) {
              splx(s);
              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_space_barrier(sc->mly_btag, sc->mly_bhandle, 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_space_barrier(sc->mly_btag, sc->mly_bhandle, 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);
      splx(s);
      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                         s, worked;
  
      s = splcam();
      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);
      }
  
      splx(s);
      if (worked) {
          if (sc->mly_state & MLY_STATE_INTERRUPTS_ON)
              taskqueue_enqueue(taskqueue_swi_giant, &sc->mly_task_complete);
          else
              mly_complete(sc, 0);
      }
  }
  
  /********************************************************************************
   * Process completed commands
   */
  static void
  mly_complete(void *context, int pending)
  {
      struct mly_softc    *sc = (struct mly_softc *)context;
      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) {
          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, wheras 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),
                                                        &Giant,
                                                        sc->mly_controllerinfo->maximum_parallel_commands,
                                                        1, devq)) == NULL) {
                  return(ENOMEM);
              }
              if (xpt_bus_register(sc->mly_cam_sim[chn], sc->mly_dev, chn)) {
                  mly_printf(sc, "CAM XPT phsyical channel registration failed\n");
                  return(ENXIO);
              }
              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),
                                                    &Giant,
                                                    sc->mly_controllerinfo->maximum_parallel_commands,
                                                    0, devq)) == NULL) {
              return(ENOMEM);
          }
          if (xpt_bus_register(sc->mly_cam_sim[chn], sc->mly_dev, chn)) {
              mly_printf(sc, "CAM XPT virtual channel registration failed\n");
              return(ENXIO);
          }
          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);
  
      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);
          }
      }
      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, xpt_periph, 
              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);
  
      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;
          strncpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
          strncpy(cpi->hba_vid, "FreeBSD", HBA_IDLEN);
          strncpy(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;
      int                                 s;
  
      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;
      }
  
      /* if there is data transfer, it must be to/from a virtual address */
      if ((csio->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_NONE) {
          if (csio->ccb_h.flags & CAM_DATA_PHYS) {                /* we can't map it */
              debug(0, "  data pointer is to physical address");
              csio->ccb_h.status = CAM_REQ_CMP_ERR;
          }
          if (csio->ccb_h.flags & CAM_SCATTER_VALID) {    /* we want to do the s/g setup */
              debug(0, "  data has premature s/g setup");
              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))) {
          s = splcam();
          xpt_freeze_simq(sim, 1);
          csio->ccb_h.status |= CAM_REQUEUE_REQ;
          sc->mly_qfrzn_cnt++;
          splx(s);
          return(error);
      }
      
      /* build the command */
      mc->mc_data = csio->data_ptr;
      mc->mc_length = csio->dxfer_len;
      mc->mc_complete = mly_cam_complete;
      mc->mc_private = csio;
  
      /* 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))) {
          s = splcam();
          xpt_freeze_simq(sim, 1);
          csio->ccb_h.status |= CAM_REQUEUE_REQ;
          sc->mly_qfrzn_cnt++;
          splx(s);
          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;
      int                         s;
  
      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;
      }
  
      s = splcam();
      if (sc->mly_qfrzn_cnt) {
          csio->ccb_h.status |= CAM_RELEASE_SIMQ;
          sc->mly_qfrzn_cnt--;
      }
      splx(s);
  
      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, "\2\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;
  
      sc->mly_state |= MLY_STATE_OPEN;
      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;
  
      sc->mly_state &= ~MLY_STATE_OPEN;
      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, s;
  
      /* allocate a command */
      if (mly_alloc_command(sc, &mc)) {
          error = ENOMEM;
          goto out;               /* XXX Linux version will wait for a command */
      }
  
      /* 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 */
      if ((error = mly_start(mc)) != 0)
          goto out;
      s = splcam();
      while (!(mc->mc_flags & MLY_CMD_COMPLETE))
          tsleep(mc, PRIBIO, "mlyioctl", 0);
      splx(s);
  
      /* 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);
      if (mc != NULL)
          mly_release_command(mc);
      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, s;
      
      /* fetch the current health status from userspace */
      if ((error = copyin(uh->HealthStatusBuffer, &mh, sizeof(mh))) != 0)
          return(error);
  
      /* spin waiting for a status update */
      s = splcam();
      error = EWOULDBLOCK;
      while ((error != 0) && (sc->mly_event_change == mh.change_counter))
          error = tsleep(&sc->mly_event_change, PRIBIO | PCATCH, "mlyhealth", 0);
      splx(s);
      
      /* copy the controller's health status buffer out (there is a race here if it changes again) */
      error = copyout(&sc->mly_mmbox->mmm_health.status, uh->HealthStatusBuffer, 
                      sizeof(uh->HealthStatusBuffer));
      return(error);
  }
  
  static int
  mly_timeout(struct mly_softc *sc)
  {
          struct mly_command *mc;
          int deadline;
  
          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));
                  }
          }
  
          timeout((timeout_t *)mly_timeout, sc, MLY_CMD_TIMEOUT * hz);
  
          return (0);
  }

Cache object: c2ee691778a1526f6e6a7ec770143a49