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megaraid_mbox.c

/*
 *
 *                Linux MegaRAID device driver
 *
 * Copyright (c) 2003-2004  LSI Logic Corporation.
 *
 *       This program is free software; you can redistribute it and/or
 *       modify it under the terms of the GNU General Public License
 *       as published by the Free Software Foundation; either version
 *       2 of the License, or (at your option) any later version.
 *
 * FILE           : megaraid_mbox.c
 * Version  : v2.20.5.1 (Nov 16 2006)
 *
 * Authors:
 *    Atul Mukker       <Atul.Mukker@lsi.com>
 *    Sreenivas Bagalkote     <Sreenivas.Bagalkote@lsi.com>
 *    Manoj Jose        <Manoj.Jose@lsi.com>
 *    Seokmann Ju
 *
 * List of supported controllers
 *
 * OEM      Product Name                  VID   DID   SSVID SSID
 * ---      ------------                  ---   ---   ----  ----
 * Dell PERC3/QC              101E  1960  1028  0471
 * Dell PERC3/DC              101E  1960  1028  0493
 * Dell PERC3/SC              101E  1960  1028  0475
 * Dell PERC3/Di              1028  1960  1028  0123
 * Dell PERC4/SC              1000  1960  1028  0520
 * Dell PERC4/DC              1000  1960  1028  0518
 * Dell PERC4/QC              1000  0407  1028  0531
 * Dell PERC4/Di              1028  000F  1028  014A
 * Dell PERC 4e/Si                  1028  0013  1028  016c
 * Dell PERC 4e/Di                  1028  0013  1028  016d
 * Dell PERC 4e/Di                  1028  0013  1028  016e
 * Dell PERC 4e/Di                  1028  0013  1028  016f
 * Dell PERC 4e/Di                  1028  0013  1028  0170
 * Dell PERC 4e/DC                  1000  0408  1028  0002
 * Dell PERC 4e/SC                  1000  0408  1028  0001
 *
 *
 * LSI MegaRAID SCSI 320-0          1000  1960  1000  A520
 * LSI MegaRAID SCSI 320-1          1000  1960  1000  0520
 * LSI MegaRAID SCSI 320-2          1000  1960  1000  0518
 * LSI MegaRAID SCSI 320-0X         1000  0407  1000  0530
 * LSI MegaRAID SCSI 320-2X         1000  0407  1000  0532
 * LSI MegaRAID SCSI 320-4X         1000  0407  1000  0531
 * LSI MegaRAID SCSI 320-1E         1000  0408  1000  0001
 * LSI MegaRAID SCSI 320-2E         1000  0408  1000  0002
 * LSI MegaRAID SATA 150-4          1000  1960  1000  4523
 * LSI MegaRAID SATA 150-6          1000  1960  1000  0523
 * LSI MegaRAID SATA 300-4X         1000  0409  1000  3004
 * LSI MegaRAID SATA 300-8X         1000  0409  1000  3008
 *
 * INTEL RAID Controller SRCU42X    1000  0407  8086  0532
 * INTEL RAID Controller SRCS16           1000  1960  8086  0523
 * INTEL RAID Controller SRCU42E    1000  0408  8086  0002
 * INTEL RAID Controller SRCZCRX    1000  0407  8086  0530
 * INTEL RAID Controller SRCS28X    1000  0409  8086  3008
 * INTEL RAID Controller SROMBU42E  1000  0408  8086  3431
 * INTEL RAID Controller SROMBU42E  1000  0408  8086  3499
 * INTEL RAID Controller SRCU51L    1000  1960  8086  0520
 *
 * FSC      MegaRAID PCI Express ROMB     1000  0408  1734  1065
 *
 * ACER     MegaRAID ROMB-2E        1000  0408  1025  004D
 *
 * NEC      MegaRAID PCI Express ROMB     1000  0408  1033  8287
 *
 * For history of changes, see Documentation/ChangeLog.megaraid
 */

#include "megaraid_mbox.h"

static int megaraid_init(void);
static void megaraid_exit(void);

static int megaraid_probe_one(struct pci_dev*, const struct pci_device_id *);
static void megaraid_detach_one(struct pci_dev *);
static void megaraid_mbox_shutdown(struct pci_dev *);

static int megaraid_io_attach(adapter_t *);
static void megaraid_io_detach(adapter_t *);

static int megaraid_init_mbox(adapter_t *);
static void megaraid_fini_mbox(adapter_t *);

static int megaraid_alloc_cmd_packets(adapter_t *);
static void megaraid_free_cmd_packets(adapter_t *);

static int megaraid_mbox_setup_dma_pools(adapter_t *);
static void megaraid_mbox_teardown_dma_pools(adapter_t *);

static int megaraid_sysfs_alloc_resources(adapter_t *);
static void megaraid_sysfs_free_resources(adapter_t *);

static int megaraid_abort_handler(struct scsi_cmnd *);
static int megaraid_reset_handler(struct scsi_cmnd *);

static int mbox_post_sync_cmd(adapter_t *, uint8_t []);
static int mbox_post_sync_cmd_fast(adapter_t *, uint8_t []);
static int megaraid_busywait_mbox(mraid_device_t *);
static int megaraid_mbox_product_info(adapter_t *);
static int megaraid_mbox_extended_cdb(adapter_t *);
static int megaraid_mbox_support_ha(adapter_t *, uint16_t *);
static int megaraid_mbox_support_random_del(adapter_t *);
static int megaraid_mbox_get_max_sg(adapter_t *);
static void megaraid_mbox_enum_raid_scsi(adapter_t *);
static void megaraid_mbox_flush_cache(adapter_t *);
static int megaraid_mbox_fire_sync_cmd(adapter_t *);

static void megaraid_mbox_display_scb(adapter_t *, scb_t *);
static void megaraid_mbox_setup_device_map(adapter_t *);

static int megaraid_queue_command(struct scsi_cmnd *,
            void (*)(struct scsi_cmnd *));
static scb_t *megaraid_mbox_build_cmd(adapter_t *, struct scsi_cmnd *, int *);
static void megaraid_mbox_runpendq(adapter_t *, scb_t *);
static void megaraid_mbox_prepare_pthru(adapter_t *, scb_t *,
            struct scsi_cmnd *);
static void megaraid_mbox_prepare_epthru(adapter_t *, scb_t *,
            struct scsi_cmnd *);

static irqreturn_t megaraid_isr(int, void *);

static void megaraid_mbox_dpc(unsigned long);

static ssize_t megaraid_sysfs_show_app_hndl(struct device *, struct device_attribute *attr, char *);
static ssize_t megaraid_sysfs_show_ldnum(struct device *, struct device_attribute *attr, char *);

static int megaraid_cmm_register(adapter_t *);
static int megaraid_cmm_unregister(adapter_t *);
static int megaraid_mbox_mm_handler(unsigned long, uioc_t *, uint32_t);
static int megaraid_mbox_mm_command(adapter_t *, uioc_t *);
static void megaraid_mbox_mm_done(adapter_t *, scb_t *);
static int gather_hbainfo(adapter_t *, mraid_hba_info_t *);
static int wait_till_fw_empty(adapter_t *);



MODULE_AUTHOR("megaraidlinux@lsi.com");
MODULE_DESCRIPTION("LSI Logic MegaRAID Mailbox Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(MEGARAID_VERSION);

/*
 * ### modules parameters for driver ###
 */

/*
 * Set to enable driver to expose unconfigured disk to kernel
 */
static int megaraid_expose_unconf_disks = 0;
module_param_named(unconf_disks, megaraid_expose_unconf_disks, int, 0);
MODULE_PARM_DESC(unconf_disks,
      "Set to expose unconfigured disks to kernel (default=0)");

/*
 * driver wait time if the adapter's mailbox is busy
 */
static unsigned int max_mbox_busy_wait = MBOX_BUSY_WAIT;
module_param_named(busy_wait, max_mbox_busy_wait, int, 0);
MODULE_PARM_DESC(busy_wait,
      "Max wait for mailbox in microseconds if busy (default=10)");

/*
 * number of sectors per IO command
 */
static unsigned int megaraid_max_sectors = MBOX_MAX_SECTORS;
module_param_named(max_sectors, megaraid_max_sectors, int, 0);
MODULE_PARM_DESC(max_sectors,
      "Maximum number of sectors per IO command (default=128)");

/*
 * number of commands per logical unit
 */
static unsigned int megaraid_cmd_per_lun = MBOX_DEF_CMD_PER_LUN;
module_param_named(cmd_per_lun, megaraid_cmd_per_lun, int, 0);
MODULE_PARM_DESC(cmd_per_lun,
      "Maximum number of commands per logical unit (default=64)");


/*
 * Fast driver load option, skip scanning for physical devices during load.
 * This would result in non-disk devices being skipped during driver load
 * time. These can be later added though, using /proc/scsi/scsi
 */
static unsigned int megaraid_fast_load = 0;
module_param_named(fast_load, megaraid_fast_load, int, 0);
MODULE_PARM_DESC(fast_load,
      "Faster loading of the driver, skips physical devices! (default=0)");


/*
 * mraid_debug level - threshold for amount of information to be displayed by
 * the driver. This level can be changed through modules parameters, ioctl or
 * sysfs/proc interface. By default, print the announcement messages only.
 */
int mraid_debug_level = CL_ANN;
module_param_named(debug_level, mraid_debug_level, int, 0);
MODULE_PARM_DESC(debug_level, "Debug level for driver (default=0)");

/*
 * ### global data ###
 */
static uint8_t megaraid_mbox_version[8] =
      { 0x02, 0x20, 0x04, 0x06, 3, 7, 20, 5 };


/*
 * PCI table for all supported controllers.
 */
static struct pci_device_id pci_id_table_g[] =  {
      {
            PCI_VENDOR_ID_DELL,
            PCI_DEVICE_ID_PERC4_DI_DISCOVERY,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4_DI_DISCOVERY,
      },
      {
            PCI_VENDOR_ID_LSI_LOGIC,
            PCI_DEVICE_ID_PERC4_SC,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4_SC,
      },
      {
            PCI_VENDOR_ID_LSI_LOGIC,
            PCI_DEVICE_ID_PERC4_DC,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4_DC,
      },
      {
            PCI_VENDOR_ID_LSI_LOGIC,
            PCI_DEVICE_ID_VERDE,
            PCI_ANY_ID,
            PCI_ANY_ID,
      },
      {
            PCI_VENDOR_ID_DELL,
            PCI_DEVICE_ID_PERC4_DI_EVERGLADES,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4_DI_EVERGLADES,
      },
      {
            PCI_VENDOR_ID_DELL,
            PCI_DEVICE_ID_PERC4E_SI_BIGBEND,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4E_SI_BIGBEND,
      },
      {
            PCI_VENDOR_ID_DELL,
            PCI_DEVICE_ID_PERC4E_DI_KOBUK,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4E_DI_KOBUK,
      },
      {
            PCI_VENDOR_ID_DELL,
            PCI_DEVICE_ID_PERC4E_DI_CORVETTE,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4E_DI_CORVETTE,
      },
      {
            PCI_VENDOR_ID_DELL,
            PCI_DEVICE_ID_PERC4E_DI_EXPEDITION,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4E_DI_EXPEDITION,
      },
      {
            PCI_VENDOR_ID_DELL,
            PCI_DEVICE_ID_PERC4E_DI_GUADALUPE,
            PCI_VENDOR_ID_DELL,
            PCI_SUBSYS_ID_PERC4E_DI_GUADALUPE,
      },
      {
            PCI_VENDOR_ID_LSI_LOGIC,
            PCI_DEVICE_ID_DOBSON,
            PCI_ANY_ID,
            PCI_ANY_ID,
      },
      {
            PCI_VENDOR_ID_AMI,
            PCI_DEVICE_ID_AMI_MEGARAID3,
            PCI_ANY_ID,
            PCI_ANY_ID,
      },
      {
            PCI_VENDOR_ID_LSI_LOGIC,
            PCI_DEVICE_ID_AMI_MEGARAID3,
            PCI_ANY_ID,
            PCI_ANY_ID,
      },
      {
            PCI_VENDOR_ID_LSI_LOGIC,
            PCI_DEVICE_ID_LINDSAY,
            PCI_ANY_ID,
            PCI_ANY_ID,
      },
      {0}   /* Terminating entry */
};
MODULE_DEVICE_TABLE(pci, pci_id_table_g);


static struct pci_driver megaraid_pci_driver = {
      .name       = "megaraid",
      .id_table   = pci_id_table_g,
      .probe            = megaraid_probe_one,
      .remove           = __devexit_p(megaraid_detach_one),
      .shutdown   = megaraid_mbox_shutdown,
};



// definitions for the device attributes for exporting logical drive number
// for a scsi address (Host, Channel, Id, Lun)

DEVICE_ATTR(megaraid_mbox_app_hndl, S_IRUSR, megaraid_sysfs_show_app_hndl,
            NULL);

// Host template initializer for megaraid mbox sysfs device attributes
static struct device_attribute *megaraid_shost_attrs[] = {
      &dev_attr_megaraid_mbox_app_hndl,
      NULL,
};


DEVICE_ATTR(megaraid_mbox_ld, S_IRUSR, megaraid_sysfs_show_ldnum, NULL);

// Host template initializer for megaraid mbox sysfs device attributes
static struct device_attribute *megaraid_sdev_attrs[] = {
      &dev_attr_megaraid_mbox_ld,
      NULL,
};

/**
 * megaraid_change_queue_depth - Change the device's queue depth
 * @sdev:   scsi device struct
 * @qdepth: depth to set
 *
 * Return value:
 *    actual depth set
 */
static int megaraid_change_queue_depth(struct scsi_device *sdev, int qdepth)
{
      if (qdepth > MBOX_MAX_SCSI_CMDS)
            qdepth = MBOX_MAX_SCSI_CMDS;
      scsi_adjust_queue_depth(sdev, 0, qdepth);
      return sdev->queue_depth;
}

/*
 * Scsi host template for megaraid unified driver
 */
static struct scsi_host_template megaraid_template_g = {
      .module                       = THIS_MODULE,
      .name                   = "LSI Logic MegaRAID driver",
      .proc_name              = "megaraid",
      .queuecommand                 = megaraid_queue_command,
      .eh_abort_handler       = megaraid_abort_handler,
      .eh_device_reset_handler      = megaraid_reset_handler,
      .eh_bus_reset_handler         = megaraid_reset_handler,
      .eh_host_reset_handler        = megaraid_reset_handler,
      .change_queue_depth           = megaraid_change_queue_depth,
      .use_clustering               = ENABLE_CLUSTERING,
      .sdev_attrs             = megaraid_sdev_attrs,
      .shost_attrs                  = megaraid_shost_attrs,
};


/**
 * megaraid_init - module load hook
 *
 * We register ourselves as hotplug enabled module and let PCI subsystem
 * discover our adapters.
 */
static int __init
megaraid_init(void)
{
      int   rval;

      // Announce the driver version
      con_log(CL_ANN, (KERN_INFO "megaraid: %s %s\n", MEGARAID_VERSION,
            MEGARAID_EXT_VERSION));

      // check validity of module parameters
      if (megaraid_cmd_per_lun > MBOX_MAX_SCSI_CMDS) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid mailbox: max commands per lun reset to %d\n",
                  MBOX_MAX_SCSI_CMDS));

            megaraid_cmd_per_lun = MBOX_MAX_SCSI_CMDS;
      }


      // register as a PCI hot-plug driver module
      rval = pci_register_driver(&megaraid_pci_driver);
      if (rval < 0) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: could not register hotplug support.\n"));
      }

      return rval;
}


/**
 * megaraid_exit - driver unload entry point
 *
 * We simply unwrap the megaraid_init routine here.
 */
static void __exit
megaraid_exit(void)
{
      con_log(CL_DLEVEL1, (KERN_NOTICE "megaraid: unloading framework\n"));

      // unregister as PCI hotplug driver
      pci_unregister_driver(&megaraid_pci_driver);

      return;
}


/**
 * megaraid_probe_one - PCI hotplug entry point
 * @pdev    : handle to this controller's PCI configuration space
 * @id            : pci device id of the class of controllers
 *
 * This routine should be called whenever a new adapter is detected by the
 * PCI hotplug susbsystem.
 */
static int __devinit
megaraid_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
      adapter_t   *adapter;


      // detected a new controller
      con_log(CL_ANN, (KERN_INFO
            "megaraid: probe new device %#4.04x:%#4.04x:%#4.04x:%#4.04x: ",
            pdev->vendor, pdev->device, pdev->subsystem_vendor,
            pdev->subsystem_device));

      con_log(CL_ANN, ("bus %d:slot %d:func %d\n", pdev->bus->number,
            PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn)));

      if (pci_enable_device(pdev)) {
            con_log(CL_ANN, (KERN_WARNING
                        "megaraid: pci_enable_device failed\n"));

            return -ENODEV;
      }

      // Enable bus-mastering on this controller
      pci_set_master(pdev);

      // Allocate the per driver initialization structure
      adapter = kzalloc(sizeof(adapter_t), GFP_KERNEL);

      if (adapter == NULL) {
            con_log(CL_ANN, (KERN_WARNING
            "megaraid: out of memory, %s %d.\n", __func__, __LINE__));

            goto out_probe_one;
      }


      // set up PCI related soft state and other pre-known parameters
      adapter->unique_id      = pdev->bus->number << 8 | pdev->devfn;
      adapter->irq            = pdev->irq;
      adapter->pdev           = pdev;

      atomic_set(&adapter->being_detached, 0);

      // Setup the default DMA mask. This would be changed later on
      // depending on hardware capabilities
      if (pci_set_dma_mask(adapter->pdev, DMA_BIT_MASK(32)) != 0) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: pci_set_dma_mask failed:%d\n", __LINE__));

            goto out_free_adapter;
      }


      // Initialize the synchronization lock for kernel and LLD
      spin_lock_init(&adapter->lock);

      // Initialize the command queues: the list of free SCBs and the list
      // of pending SCBs.
      INIT_LIST_HEAD(&adapter->kscb_pool);
      spin_lock_init(SCSI_FREE_LIST_LOCK(adapter));

      INIT_LIST_HEAD(&adapter->pend_list);
      spin_lock_init(PENDING_LIST_LOCK(adapter));

      INIT_LIST_HEAD(&adapter->completed_list);
      spin_lock_init(COMPLETED_LIST_LOCK(adapter));


      // Start the mailbox based controller
      if (megaraid_init_mbox(adapter) != 0) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: maibox adapter did not initialize\n"));

            goto out_free_adapter;
      }

      // Register with LSI Common Management Module
      if (megaraid_cmm_register(adapter) != 0) {

            con_log(CL_ANN, (KERN_WARNING
            "megaraid: could not register with management module\n"));

            goto out_fini_mbox;
      }

      // setup adapter handle in PCI soft state
      pci_set_drvdata(pdev, adapter);

      // attach with scsi mid-layer
      if (megaraid_io_attach(adapter) != 0) {

            con_log(CL_ANN, (KERN_WARNING "megaraid: io attach failed\n"));

            goto out_cmm_unreg;
      }

      return 0;

out_cmm_unreg:
      pci_set_drvdata(pdev, NULL);
      megaraid_cmm_unregister(adapter);
out_fini_mbox:
      megaraid_fini_mbox(adapter);
out_free_adapter:
      kfree(adapter);
out_probe_one:
      pci_disable_device(pdev);

      return -ENODEV;
}


/**
 * megaraid_detach_one - release framework resources and call LLD release routine
 * @pdev    : handle for our PCI cofiguration space
 *
 * This routine is called during driver unload. We free all the allocated
 * resources and call the corresponding LLD so that it can also release all
 * its resources.
 *
 * This routine is also called from the PCI hotplug system.
 */
static void
megaraid_detach_one(struct pci_dev *pdev)
{
      adapter_t         *adapter;
      struct Scsi_Host  *host;


      // Start a rollback on this adapter
      adapter = pci_get_drvdata(pdev);

      if (!adapter) {
            con_log(CL_ANN, (KERN_CRIT
            "megaraid: Invalid detach on %#4.04x:%#4.04x:%#4.04x:%#4.04x\n",
                  pdev->vendor, pdev->device, pdev->subsystem_vendor,
                  pdev->subsystem_device));

            return;
      }
      else {
            con_log(CL_ANN, (KERN_NOTICE
            "megaraid: detaching device %#4.04x:%#4.04x:%#4.04x:%#4.04x\n",
                  pdev->vendor, pdev->device, pdev->subsystem_vendor,
                  pdev->subsystem_device));
      }


      host = adapter->host;

      // do not allow any more requests from the management module for this
      // adapter.
      // FIXME: How do we account for the request which might still be
      // pending with us?
      atomic_set(&adapter->being_detached, 1);

      // detach from the IO sub-system
      megaraid_io_detach(adapter);

      // reset the device state in the PCI structure. We check this
      // condition when we enter here. If the device state is NULL,
      // that would mean the device has already been removed
      pci_set_drvdata(pdev, NULL);

      // Unregister from common management module
      //
      // FIXME: this must return success or failure for conditions if there
      // is a command pending with LLD or not.
      megaraid_cmm_unregister(adapter);

      // finalize the mailbox based controller and release all resources
      megaraid_fini_mbox(adapter);

      kfree(adapter);

      scsi_host_put(host);

      pci_disable_device(pdev);

      return;
}


/**
 * megaraid_mbox_shutdown - PCI shutdown for megaraid HBA
 * @pdev          : generic driver model device
 *
 * Shutdown notification, perform flush cache.
 */
static void
megaraid_mbox_shutdown(struct pci_dev *pdev)
{
      adapter_t         *adapter = pci_get_drvdata(pdev);
      static int        counter;

      if (!adapter) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: null device in shutdown\n"));
            return;
      }

      // flush caches now
      con_log(CL_ANN, (KERN_INFO "megaraid: flushing adapter %d...",
            counter++));

      megaraid_mbox_flush_cache(adapter);

      con_log(CL_ANN, ("done\n"));
}


/**
 * megaraid_io_attach - attach a device with the IO subsystem
 * @adapter       : controller's soft state
 *
 * Attach this device with the IO subsystem.
 */
static int
megaraid_io_attach(adapter_t *adapter)
{
      struct Scsi_Host  *host;

      // Initialize SCSI Host structure
      host = scsi_host_alloc(&megaraid_template_g, 8);
      if (!host) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid mbox: scsi_register failed\n"));

            return -1;
      }

      SCSIHOST2ADAP(host)     = (caddr_t)adapter;
      adapter->host           = host;

      host->irq         = adapter->irq;
      host->unique_id         = adapter->unique_id;
      host->can_queue         = adapter->max_cmds;
      host->this_id           = adapter->init_id;
      host->sg_tablesize      = adapter->sglen;
      host->max_sectors = adapter->max_sectors;
      host->cmd_per_lun = adapter->cmd_per_lun;
      host->max_channel = adapter->max_channel;
      host->max_id            = adapter->max_target;
      host->max_lun           = adapter->max_lun;


      // notify mid-layer about the new controller
      if (scsi_add_host(host, &adapter->pdev->dev)) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid mbox: scsi_add_host failed\n"));

            scsi_host_put(host);

            return -1;
      }

      scsi_scan_host(host);

      return 0;
}


/**
 * megaraid_io_detach - detach a device from the IO subsystem
 * @adapter       : controller's soft state
 *
 * Detach this device from the IO subsystem.
 */
static void
megaraid_io_detach(adapter_t *adapter)
{
      struct Scsi_Host  *host;

      con_log(CL_DLEVEL1, (KERN_INFO "megaraid: io detach\n"));

      host = adapter->host;

      scsi_remove_host(host);

      return;
}


/*
 * START: Mailbox Low Level Driver
 *
 * This is section specific to the single mailbox based controllers
 */

/**
 * megaraid_init_mbox - initialize controller
 * @adapter       : our soft state
 *
 * - Allocate 16-byte aligned mailbox memory for firmware handshake
 * - Allocate controller's memory resources
 * - Find out all initialization data
 * - Allocate memory required for all the commands
 * - Use internal library of FW routines, build up complete soft state
 */
static int __devinit
megaraid_init_mbox(adapter_t *adapter)
{
      struct pci_dev          *pdev;
      mraid_device_t          *raid_dev;
      int               i;
      uint32_t          magic64;


      adapter->ito      = MBOX_TIMEOUT;
      pdev        = adapter->pdev;

      /*
       * Allocate and initialize the init data structure for mailbox
       * controllers
       */
      raid_dev = kzalloc(sizeof(mraid_device_t), GFP_KERNEL);
      if (raid_dev == NULL) return -1;


      /*
       * Attach the adapter soft state to raid device soft state
       */
      adapter->raid_device    = (caddr_t)raid_dev;
      raid_dev->fast_load     = megaraid_fast_load;


      // our baseport
      raid_dev->baseport = pci_resource_start(pdev, 0);

      if (pci_request_regions(pdev, "MegaRAID: LSI Logic Corporation") != 0) {

            con_log(CL_ANN, (KERN_WARNING
                        "megaraid: mem region busy\n"));

            goto out_free_raid_dev;
      }

      raid_dev->baseaddr = ioremap_nocache(raid_dev->baseport, 128);

      if (!raid_dev->baseaddr) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: could not map hba memory\n") );

            goto out_release_regions;
      }

      /* initialize the mutual exclusion lock for the mailbox */
      spin_lock_init(&raid_dev->mailbox_lock);

      /* allocate memory required for commands */
      if (megaraid_alloc_cmd_packets(adapter) != 0)
            goto out_iounmap;

      /*
       * Issue SYNC cmd to flush the pending cmds in the adapter
       * and initialize its internal state
       */

      if (megaraid_mbox_fire_sync_cmd(adapter))
            con_log(CL_ANN, ("megaraid: sync cmd failed\n"));

      /*
       * Setup the rest of the soft state using the library of
       * FW routines
       */

      /* request IRQ and register the interrupt service routine */
      if (request_irq(adapter->irq, megaraid_isr, IRQF_SHARED, "megaraid",
            adapter)) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: Couldn't register IRQ %d!\n", adapter->irq));
            goto out_alloc_cmds;

      }

      // Product info
      if (megaraid_mbox_product_info(adapter) != 0)
            goto out_free_irq;

      // Do we support extended CDBs
      adapter->max_cdb_sz = 10;
      if (megaraid_mbox_extended_cdb(adapter) == 0) {
            adapter->max_cdb_sz = 16;
      }

      /*
       * Do we support cluster environment, if we do, what is the initiator
       * id.
       * NOTE: In a non-cluster aware firmware environment, the LLD should
       * return 7 as initiator id.
       */
      adapter->ha       = 0;
      adapter->init_id  = -1;
      if (megaraid_mbox_support_ha(adapter, &adapter->init_id) == 0) {
            adapter->ha = 1;
      }

      /*
       * Prepare the device ids array to have the mapping between the kernel
       * device address and megaraid device address.
       * We export the physical devices on their actual addresses. The
       * logical drives are exported on a virtual SCSI channel
       */
      megaraid_mbox_setup_device_map(adapter);

      // If the firmware supports random deletion, update the device id map
      if (megaraid_mbox_support_random_del(adapter)) {

            // Change the logical drives numbers in device_ids array one
            // slot in device_ids is reserved for target id, that's why
            // "<=" below
            for (i = 0; i <= MAX_LOGICAL_DRIVES_40LD; i++) {
                  adapter->device_ids[adapter->max_channel][i] += 0x80;
            }
            adapter->device_ids[adapter->max_channel][adapter->init_id] =
                  0xFF;

            raid_dev->random_del_supported = 1;
      }

      /*
       * find out the maximum number of scatter-gather elements supported by
       * this firmware
       */
      adapter->sglen = megaraid_mbox_get_max_sg(adapter);

      // enumerate RAID and SCSI channels so that all devices on SCSI
      // channels can later be exported, including disk devices
      megaraid_mbox_enum_raid_scsi(adapter);

      /*
       * Other parameters required by upper layer
       *
       * maximum number of sectors per IO command
       */
      adapter->max_sectors = megaraid_max_sectors;

      /*
       * number of queued commands per LUN.
       */
      adapter->cmd_per_lun = megaraid_cmd_per_lun;

      /*
       * Allocate resources required to issue FW calls, when sysfs is
       * accessed
       */
      if (megaraid_sysfs_alloc_resources(adapter) != 0)
            goto out_free_irq;

      // Set the DMA mask to 64-bit. All supported controllers as capable of
      // DMA in this range
      pci_read_config_dword(adapter->pdev, PCI_CONF_AMISIG64, &magic64);

      if (((magic64 == HBA_SIGNATURE_64_BIT) &&
            ((adapter->pdev->subsystem_device !=
            PCI_SUBSYS_ID_MEGARAID_SATA_150_6) &&
            (adapter->pdev->subsystem_device !=
            PCI_SUBSYS_ID_MEGARAID_SATA_150_4))) ||
            (adapter->pdev->vendor == PCI_VENDOR_ID_LSI_LOGIC &&
            adapter->pdev->device == PCI_DEVICE_ID_VERDE) ||
            (adapter->pdev->vendor == PCI_VENDOR_ID_LSI_LOGIC &&
            adapter->pdev->device == PCI_DEVICE_ID_DOBSON) ||
            (adapter->pdev->vendor == PCI_VENDOR_ID_LSI_LOGIC &&
            adapter->pdev->device == PCI_DEVICE_ID_LINDSAY) ||
            (adapter->pdev->vendor == PCI_VENDOR_ID_DELL &&
            adapter->pdev->device == PCI_DEVICE_ID_PERC4_DI_EVERGLADES) ||
            (adapter->pdev->vendor == PCI_VENDOR_ID_DELL &&
            adapter->pdev->device == PCI_DEVICE_ID_PERC4E_DI_KOBUK)) {
            if (pci_set_dma_mask(adapter->pdev, DMA_BIT_MASK(64))) {
                  con_log(CL_ANN, (KERN_WARNING
                        "megaraid: DMA mask for 64-bit failed\n"));

                  if (pci_set_dma_mask (adapter->pdev, DMA_BIT_MASK(32))) {
                        con_log(CL_ANN, (KERN_WARNING
                              "megaraid: 32-bit DMA mask failed\n"));
                        goto out_free_sysfs_res;
                  }
            }
      }

      // setup tasklet for DPC
      tasklet_init(&adapter->dpc_h, megaraid_mbox_dpc,
                  (unsigned long)adapter);

      con_log(CL_DLEVEL1, (KERN_INFO
            "megaraid mbox hba successfully initialized\n"));

      return 0;

out_free_sysfs_res:
      megaraid_sysfs_free_resources(adapter);
out_free_irq:
      free_irq(adapter->irq, adapter);
out_alloc_cmds:
      megaraid_free_cmd_packets(adapter);
out_iounmap:
      iounmap(raid_dev->baseaddr);
out_release_regions:
      pci_release_regions(pdev);
out_free_raid_dev:
      kfree(raid_dev);

      return -1;
}


/**
 * megaraid_fini_mbox - undo controller initialization
 * @adapter       : our soft state
 */
static void
megaraid_fini_mbox(adapter_t *adapter)
{
      mraid_device_t *raid_dev = ADAP2RAIDDEV(adapter);

      // flush all caches
      megaraid_mbox_flush_cache(adapter);

      tasklet_kill(&adapter->dpc_h);

      megaraid_sysfs_free_resources(adapter);

      megaraid_free_cmd_packets(adapter);

      free_irq(adapter->irq, adapter);

      iounmap(raid_dev->baseaddr);

      pci_release_regions(adapter->pdev);

      kfree(raid_dev);

      return;
}


/**
 * megaraid_alloc_cmd_packets - allocate shared mailbox
 * @adapter       : soft state of the raid controller
 *
 * Allocate and align the shared mailbox. This maibox is used to issue
 * all the commands. For IO based controllers, the mailbox is also regsitered
 * with the FW. Allocate memory for all commands as well.
 * This is our big allocator.
 */
static int
megaraid_alloc_cmd_packets(adapter_t *adapter)
{
      mraid_device_t          *raid_dev = ADAP2RAIDDEV(adapter);
      struct pci_dev          *pdev;
      unsigned long           align;
      scb_t             *scb;
      mbox_ccb_t        *ccb;
      struct mraid_pci_blk    *epthru_pci_blk;
      struct mraid_pci_blk    *sg_pci_blk;
      struct mraid_pci_blk    *mbox_pci_blk;
      int               i;

      pdev = adapter->pdev;

      /*
       * Setup the mailbox
       * Allocate the common 16-byte aligned memory for the handshake
       * mailbox.
       */
      raid_dev->una_mbox64 = pci_alloc_consistent(adapter->pdev,
                  sizeof(mbox64_t), &raid_dev->una_mbox64_dma);

      if (!raid_dev->una_mbox64) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: out of memory, %s %d\n", __func__,
                  __LINE__));
            return -1;
      }
      memset(raid_dev->una_mbox64, 0, sizeof(mbox64_t));

      /*
       * Align the mailbox at 16-byte boundary
       */
      raid_dev->mbox    = &raid_dev->una_mbox64->mbox32;

      raid_dev->mbox    = (mbox_t *)((((unsigned long)raid_dev->mbox) + 15) &
                        (~0UL ^ 0xFUL));

      raid_dev->mbox64 = (mbox64_t *)(((unsigned long)raid_dev->mbox) - 8);

      align = ((void *)raid_dev->mbox -
                  ((void *)&raid_dev->una_mbox64->mbox32));

      raid_dev->mbox_dma = (unsigned long)raid_dev->una_mbox64_dma + 8 +
                  align;

      // Allocate memory for commands issued internally
      adapter->ibuf = pci_alloc_consistent(pdev, MBOX_IBUF_SIZE,
                        &adapter->ibuf_dma_h);
      if (!adapter->ibuf) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: out of memory, %s %d\n", __func__,
                  __LINE__));

            goto out_free_common_mbox;
      }
      memset(adapter->ibuf, 0, MBOX_IBUF_SIZE);

      // Allocate memory for our SCSI Command Blocks and their associated
      // memory

      /*
       * Allocate memory for the base list of scb. Later allocate memory for
       * CCBs and embedded components of each CCB and point the pointers in
       * scb to the allocated components
       * NOTE: The code to allocate SCB will be duplicated in all the LLD
       * since the calling routine does not yet know the number of available
       * commands.
       */
      adapter->kscb_list = kcalloc(MBOX_MAX_SCSI_CMDS, sizeof(scb_t), GFP_KERNEL);

      if (adapter->kscb_list == NULL) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: out of memory, %s %d\n", __func__,
                  __LINE__));
            goto out_free_ibuf;
      }

      // memory allocation for our command packets
      if (megaraid_mbox_setup_dma_pools(adapter) != 0) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: out of memory, %s %d\n", __func__,
                  __LINE__));
            goto out_free_scb_list;
      }

      // Adjust the scb pointers and link in the free pool
      epthru_pci_blk    = raid_dev->epthru_pool;
      sg_pci_blk  = raid_dev->sg_pool;
      mbox_pci_blk      = raid_dev->mbox_pool;

      for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
            scb               = adapter->kscb_list + i;
            ccb               = raid_dev->ccb_list + i;

            ccb->mbox   = (mbox_t *)(mbox_pci_blk[i].vaddr + 16);
            ccb->raw_mbox     = (uint8_t *)ccb->mbox;
            ccb->mbox64 = (mbox64_t *)(mbox_pci_blk[i].vaddr + 8);
            ccb->mbox_dma_h   = (unsigned long)mbox_pci_blk[i].dma_addr + 16;

            // make sure the mailbox is aligned properly
            if (ccb->mbox_dma_h & 0x0F) {
                  con_log(CL_ANN, (KERN_CRIT
                        "megaraid mbox: not aligned on 16-bytes\n"));

                  goto out_teardown_dma_pools;
            }

            ccb->epthru       = (mraid_epassthru_t *)
                                    epthru_pci_blk[i].vaddr;
            ccb->epthru_dma_h = epthru_pci_blk[i].dma_addr;
            ccb->pthru        = (mraid_passthru_t *)ccb->epthru;
            ccb->pthru_dma_h  = ccb->epthru_dma_h;


            ccb->sgl64        = (mbox_sgl64 *)sg_pci_blk[i].vaddr;
            ccb->sgl_dma_h          = sg_pci_blk[i].dma_addr;
            ccb->sgl32        = (mbox_sgl32 *)ccb->sgl64;

            scb->ccb          = (caddr_t)ccb;
            scb->gp                 = 0;

            scb->sno          = i;  // command index

            scb->scp          = NULL;
            scb->state        = SCB_FREE;
            scb->dma_direction      = PCI_DMA_NONE;
            scb->dma_type           = MRAID_DMA_NONE;
            scb->dev_channel  = -1;
            scb->dev_target         = -1;

            // put scb in the free pool
            list_add_tail(&scb->list, &adapter->kscb_pool);
      }

      return 0;

out_teardown_dma_pools:
      megaraid_mbox_teardown_dma_pools(adapter);
out_free_scb_list:
      kfree(adapter->kscb_list);
out_free_ibuf:
      pci_free_consistent(pdev, MBOX_IBUF_SIZE, (void *)adapter->ibuf,
            adapter->ibuf_dma_h);
out_free_common_mbox:
      pci_free_consistent(adapter->pdev, sizeof(mbox64_t),
            (caddr_t)raid_dev->una_mbox64, raid_dev->una_mbox64_dma);

      return -1;
}


/**
 * megaraid_free_cmd_packets - free memory
 * @adapter       : soft state of the raid controller
 *
 * Release memory resources allocated for commands.
 */
static void
megaraid_free_cmd_packets(adapter_t *adapter)
{
      mraid_device_t *raid_dev = ADAP2RAIDDEV(adapter);

      megaraid_mbox_teardown_dma_pools(adapter);

      kfree(adapter->kscb_list);

      pci_free_consistent(adapter->pdev, MBOX_IBUF_SIZE,
            (void *)adapter->ibuf, adapter->ibuf_dma_h);

      pci_free_consistent(adapter->pdev, sizeof(mbox64_t),
            (caddr_t)raid_dev->una_mbox64, raid_dev->una_mbox64_dma);
      return;
}


/**
 * megaraid_mbox_setup_dma_pools - setup dma pool for command packets
 * @adapter       : HBA soft state
 *
 * Setup the dma pools for mailbox, passthru and extended passthru structures,
 * and scatter-gather lists.
 */
static int
megaraid_mbox_setup_dma_pools(adapter_t *adapter)
{
      mraid_device_t          *raid_dev = ADAP2RAIDDEV(adapter);
      struct mraid_pci_blk    *epthru_pci_blk;
      struct mraid_pci_blk    *sg_pci_blk;
      struct mraid_pci_blk    *mbox_pci_blk;
      int               i;



      // Allocate memory for 16-bytes aligned mailboxes
      raid_dev->mbox_pool_handle = pci_pool_create("megaraid mbox pool",
                                    adapter->pdev,
                                    sizeof(mbox64_t) + 16,
                                    16, 0);

      if (raid_dev->mbox_pool_handle == NULL) {
            goto fail_setup_dma_pool;
      }

      mbox_pci_blk = raid_dev->mbox_pool;
      for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
            mbox_pci_blk[i].vaddr = pci_pool_alloc(
                                    raid_dev->mbox_pool_handle,
                                    GFP_KERNEL,
                                    &mbox_pci_blk[i].dma_addr);
            if (!mbox_pci_blk[i].vaddr) {
                  goto fail_setup_dma_pool;
            }
      }

      /*
       * Allocate memory for each embedded passthru strucuture pointer
       * Request for a 128 bytes aligned structure for each passthru command
       * structure
       * Since passthru and extended passthru commands are exclusive, they
       * share common memory pool. Passthru structures piggyback on memory
       * allocted to extended passthru since passthru is smaller of the two
       */
      raid_dev->epthru_pool_handle = pci_pool_create("megaraid mbox pthru",
                  adapter->pdev, sizeof(mraid_epassthru_t), 128, 0);

      if (raid_dev->epthru_pool_handle == NULL) {
            goto fail_setup_dma_pool;
      }

      epthru_pci_blk = raid_dev->epthru_pool;
      for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
            epthru_pci_blk[i].vaddr = pci_pool_alloc(
                                    raid_dev->epthru_pool_handle,
                                    GFP_KERNEL,
                                    &epthru_pci_blk[i].dma_addr);
            if (!epthru_pci_blk[i].vaddr) {
                  goto fail_setup_dma_pool;
            }
      }


      // Allocate memory for each scatter-gather list. Request for 512 bytes
      // alignment for each sg list
      raid_dev->sg_pool_handle = pci_pool_create("megaraid mbox sg",
                              adapter->pdev,
                              sizeof(mbox_sgl64) * MBOX_MAX_SG_SIZE,
                              512, 0);

      if (raid_dev->sg_pool_handle == NULL) {
            goto fail_setup_dma_pool;
      }

      sg_pci_blk = raid_dev->sg_pool;
      for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
            sg_pci_blk[i].vaddr = pci_pool_alloc(
                                    raid_dev->sg_pool_handle,
                                    GFP_KERNEL,
                                    &sg_pci_blk[i].dma_addr);
            if (!sg_pci_blk[i].vaddr) {
                  goto fail_setup_dma_pool;
            }
      }

      return 0;

fail_setup_dma_pool:
      megaraid_mbox_teardown_dma_pools(adapter);
      return -1;
}


/**
 * megaraid_mbox_teardown_dma_pools - teardown dma pools for command packets
 * @adapter       : HBA soft state
 *
 * Teardown the dma pool for mailbox, passthru and extended passthru
 * structures, and scatter-gather lists.
 */
static void
megaraid_mbox_teardown_dma_pools(adapter_t *adapter)
{
      mraid_device_t          *raid_dev = ADAP2RAIDDEV(adapter);
      struct mraid_pci_blk    *epthru_pci_blk;
      struct mraid_pci_blk    *sg_pci_blk;
      struct mraid_pci_blk    *mbox_pci_blk;
      int               i;


      sg_pci_blk = raid_dev->sg_pool;
      for (i = 0; i < MBOX_MAX_SCSI_CMDS && sg_pci_blk[i].vaddr; i++) {
            pci_pool_free(raid_dev->sg_pool_handle, sg_pci_blk[i].vaddr,
                  sg_pci_blk[i].dma_addr);
      }
      if (raid_dev->sg_pool_handle)
            pci_pool_destroy(raid_dev->sg_pool_handle);


      epthru_pci_blk = raid_dev->epthru_pool;
      for (i = 0; i < MBOX_MAX_SCSI_CMDS && epthru_pci_blk[i].vaddr; i++) {
            pci_pool_free(raid_dev->epthru_pool_handle,
                  epthru_pci_blk[i].vaddr, epthru_pci_blk[i].dma_addr);
      }
      if (raid_dev->epthru_pool_handle)
            pci_pool_destroy(raid_dev->epthru_pool_handle);


      mbox_pci_blk = raid_dev->mbox_pool;
      for (i = 0; i < MBOX_MAX_SCSI_CMDS && mbox_pci_blk[i].vaddr; i++) {
            pci_pool_free(raid_dev->mbox_pool_handle,
                  mbox_pci_blk[i].vaddr, mbox_pci_blk[i].dma_addr);
      }
      if (raid_dev->mbox_pool_handle)
            pci_pool_destroy(raid_dev->mbox_pool_handle);

      return;
}


/**
 * megaraid_alloc_scb - detach and return a scb from the free list
 * @adapter : controller's soft state
 * @scp           : pointer to the scsi command to be executed
 *
 * Return the scb from the head of the free list. %NULL if there are none
 * available.
 */
static scb_t *
megaraid_alloc_scb(adapter_t *adapter, struct scsi_cmnd *scp)
{
      struct list_head  *head = &adapter->kscb_pool;
      scb_t             *scb = NULL;
      unsigned long           flags;

      // detach scb from free pool
      spin_lock_irqsave(SCSI_FREE_LIST_LOCK(adapter), flags);

      if (list_empty(head)) {
            spin_unlock_irqrestore(SCSI_FREE_LIST_LOCK(adapter), flags);
            return NULL;
      }

      scb = list_entry(head->next, scb_t, list);
      list_del_init(&scb->list);

      spin_unlock_irqrestore(SCSI_FREE_LIST_LOCK(adapter), flags);

      scb->state  = SCB_ACTIVE;
      scb->scp    = scp;
      scb->dma_type     = MRAID_DMA_NONE;

      return scb;
}


/**
 * megaraid_dealloc_scb - return the scb to the free pool
 * @adapter : controller's soft state
 * @scb           : scb to be freed
 *
 * Return the scb back to the free list of scbs. The caller must 'flush' the
 * SCB before calling us. E.g., performing pci_unamp and/or pci_sync etc.
 * NOTE NOTE: Make sure the scb is not on any list before calling this
 * routine.
 */
static inline void
megaraid_dealloc_scb(adapter_t *adapter, scb_t *scb)
{
      unsigned long           flags;

      // put scb in the free pool
      scb->state  = SCB_FREE;
      scb->scp    = NULL;
      spin_lock_irqsave(SCSI_FREE_LIST_LOCK(adapter), flags);

      list_add(&scb->list, &adapter->kscb_pool);

      spin_unlock_irqrestore(SCSI_FREE_LIST_LOCK(adapter), flags);

      return;
}


/**
 * megaraid_mbox_mksgl - make the scatter-gather list
 * @adapter : controller's soft state
 * @scb           : scsi control block
 *
 * Prepare the scatter-gather list.
 */
static int
megaraid_mbox_mksgl(adapter_t *adapter, scb_t *scb)
{
      struct scatterlist      *sgl;
      mbox_ccb_t        *ccb;
      struct scsi_cmnd  *scp;
      int               sgcnt;
      int               i;


      scp   = scb->scp;
      ccb   = (mbox_ccb_t *)scb->ccb;

      sgcnt = scsi_dma_map(scp);
      BUG_ON(sgcnt < 0 || sgcnt > adapter->sglen);

      // no mapping required if no data to be transferred
      if (!sgcnt)
            return 0;

      scb->dma_type = MRAID_DMA_WSG;

      scsi_for_each_sg(scp, sgl, sgcnt, i) {
            ccb->sgl64[i].address   = sg_dma_address(sgl);
            ccb->sgl64[i].length    = sg_dma_len(sgl);
      }

      // Return count of SG nodes
      return sgcnt;
}


/**
 * mbox_post_cmd - issue a mailbox command
 * @adapter : controller's soft state
 * @scb           : command to be issued
 *
 * Post the command to the controller if mailbox is available.
 */
static int
mbox_post_cmd(adapter_t *adapter, scb_t *scb)
{
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);
      mbox64_t    *mbox64;
      mbox_t            *mbox;
      mbox_ccb_t  *ccb;
      unsigned long     flags;
      unsigned int      i = 0;


      ccb   = (mbox_ccb_t *)scb->ccb;
      mbox  = raid_dev->mbox;
      mbox64      = raid_dev->mbox64;

      /*
       * Check for busy mailbox. If it is, return failure - the caller
       * should retry later.
       */
      spin_lock_irqsave(MAILBOX_LOCK(raid_dev), flags);

      if (unlikely(mbox->busy)) {
            do {
                  udelay(1);
                  i++;
                  rmb();
            } while(mbox->busy && (i < max_mbox_busy_wait));

            if (mbox->busy) {

                  spin_unlock_irqrestore(MAILBOX_LOCK(raid_dev), flags);

                  return -1;
            }
      }


      // Copy this command's mailbox data into "adapter's" mailbox
      memcpy((caddr_t)mbox64, (caddr_t)ccb->mbox64, 22);
      mbox->cmdid = scb->sno;

      adapter->outstanding_cmds++;

      if (scb->dma_direction == PCI_DMA_TODEVICE)
            pci_dma_sync_sg_for_device(adapter->pdev,
                                 scsi_sglist(scb->scp),
                                 scsi_sg_count(scb->scp),
                                 PCI_DMA_TODEVICE);

      mbox->busy  = 1;  // Set busy
      mbox->poll  = 0;
      mbox->ack   = 0;
      wmb();

      WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);

      spin_unlock_irqrestore(MAILBOX_LOCK(raid_dev), flags);

      return 0;
}


/**
 * megaraid_queue_command - generic queue entry point for all LLDs
 * @scp           : pointer to the scsi command to be executed
 * @done    : callback routine to be called after the cmd has be completed
 *
 * Queue entry point for mailbox based controllers.
 */
static int
megaraid_queue_command(struct scsi_cmnd *scp, void (*done)(struct scsi_cmnd *))
{
      adapter_t   *adapter;
      scb_t       *scb;
      int         if_busy;

      adapter           = SCP2ADAPTER(scp);
      scp->scsi_done    = done;
      scp->result = 0;

      /*
       * Allocate and build a SCB request
       * if_busy flag will be set if megaraid_mbox_build_cmd() command could
       * not allocate scb. We will return non-zero status in that case.
       * NOTE: scb can be null even though certain commands completed
       * successfully, e.g., MODE_SENSE and TEST_UNIT_READY, it would
       * return 0 in that case, and we would do the callback right away.
       */
      if_busy     = 0;
      scb = megaraid_mbox_build_cmd(adapter, scp, &if_busy);
      if (!scb) { // command already completed
            done(scp);
            return 0;
      }

      megaraid_mbox_runpendq(adapter, scb);
      return if_busy;
}

/**
 * megaraid_mbox_build_cmd - transform the mid-layer scsi commands
 * @adapter : controller's soft state
 * @scp           : mid-layer scsi command pointer
 * @busy    : set if request could not be completed because of lack of
 *          resources
 *
 * Transform the mid-layer scsi command to megaraid firmware lingua.
 * Convert the command issued by mid-layer to format understood by megaraid
 * firmware. We also complete certain commands without sending them to firmware.
 */
static scb_t *
megaraid_mbox_build_cmd(adapter_t *adapter, struct scsi_cmnd *scp, int *busy)
{
      mraid_device_t          *rdev = ADAP2RAIDDEV(adapter);
      int               channel;
      int               target;
      int               islogical;
      mbox_ccb_t        *ccb;
      mraid_passthru_t  *pthru;
      mbox64_t          *mbox64;
      mbox_t                  *mbox;
      scb_t             *scb;
      char              skip[] = "skipping";
      char              scan[] = "scanning";
      char              *ss;


      /*
       * Get the appropriate device map for the device this command is
       * intended for
       */
      MRAID_GET_DEVICE_MAP(adapter, scp, channel, target, islogical);

      /*
       * Logical drive commands
       */
      if (islogical) {
            switch (scp->cmnd[0]) {
            case TEST_UNIT_READY:
                  /*
                   * Do we support clustering and is the support enabled
                   * If no, return success always
                   */
                  if (!adapter->ha) {
                        scp->result = (DID_OK << 16);
                        return NULL;
                  }

                  if (!(scb = megaraid_alloc_scb(adapter, scp))) {
                        scp->result = (DID_ERROR << 16);
                        *busy = 1;
                        return NULL;
                  }

                  scb->dma_direction      = scp->sc_data_direction;
                  scb->dev_channel  = 0xFF;
                  scb->dev_target         = target;
                  ccb               = (mbox_ccb_t *)scb->ccb;

                  /*
                   * The command id will be provided by the command
                   * issuance routine
                   */
                  ccb->raw_mbox[0]  = CLUSTER_CMD;
                  ccb->raw_mbox[2]  = RESERVATION_STATUS;
                  ccb->raw_mbox[3]  = target;

                  return scb;

            case MODE_SENSE:
            {
                  struct scatterlist      *sgl;
                  caddr_t                 vaddr;

                  sgl = scsi_sglist(scp);
                  if (sg_page(sgl)) {
                        vaddr = (caddr_t) sg_virt(&sgl[0]);

                        memset(vaddr, 0, scp->cmnd[4]);
                  }
                  else {
                        con_log(CL_ANN, (KERN_WARNING
                                     "megaraid mailbox: invalid sg:%d\n",
                                     __LINE__));
                  }
            }
            scp->result = (DID_OK << 16);
            return NULL;

            case INQUIRY:
                  /*
                   * Display the channel scan for logical drives
                   * Do not display scan for a channel if already done.
                   */
                  if (!(rdev->last_disp & (1L << SCP2CHANNEL(scp)))) {

                        con_log(CL_ANN, (KERN_INFO
                              "scsi[%d]: scanning scsi channel %d",
                              adapter->host->host_no,
                              SCP2CHANNEL(scp)));

                        con_log(CL_ANN, (
                              " [virtual] for logical drives\n"));

                        rdev->last_disp |= (1L << SCP2CHANNEL(scp));
                  }

                  if (scp->cmnd[1] & MEGA_SCSI_INQ_EVPD) {
                        scp->sense_buffer[0] = 0x70;
                        scp->sense_buffer[2] = ILLEGAL_REQUEST;
                        scp->sense_buffer[12] = MEGA_INVALID_FIELD_IN_CDB;
                        scp->result = CHECK_CONDITION << 1;
                        return NULL;
                  }

                  /* Fall through */

            case READ_CAPACITY:
                  /*
                   * Do not allow LUN > 0 for logical drives and
                   * requests for more than 40 logical drives
                   */
                  if (SCP2LUN(scp)) {
                        scp->result = (DID_BAD_TARGET << 16);
                        return NULL;
                  }
                  if ((target % 0x80) >= MAX_LOGICAL_DRIVES_40LD) {
                        scp->result = (DID_BAD_TARGET << 16);
                        return NULL;
                  }


                  /* Allocate a SCB and initialize passthru */
                  if (!(scb = megaraid_alloc_scb(adapter, scp))) {
                        scp->result = (DID_ERROR << 16);
                        *busy = 1;
                        return NULL;
                  }

                  ccb               = (mbox_ccb_t *)scb->ccb;
                  scb->dev_channel  = 0xFF;
                  scb->dev_target         = target;
                  pthru             = ccb->pthru;
                  mbox              = ccb->mbox;
                  mbox64                  = ccb->mbox64;

                  pthru->timeout          = 0;
                  pthru->ars        = 1;
                  pthru->reqsenselen      = 14;
                  pthru->islogical  = 1;
                  pthru->logdrv           = target;
                  pthru->cdblen           = scp->cmd_len;
                  memcpy(pthru->cdb, scp->cmnd, scp->cmd_len);

                  mbox->cmd         = MBOXCMD_PASSTHRU64;
                  scb->dma_direction      = scp->sc_data_direction;

                  pthru->dataxferlen      = scsi_bufflen(scp);
                  pthru->dataxferaddr     = ccb->sgl_dma_h;
                  pthru->numsge           = megaraid_mbox_mksgl(adapter,
                                          scb);

                  mbox->xferaddr          = 0xFFFFFFFF;
                  mbox64->xferaddr_lo     = (uint32_t )ccb->pthru_dma_h;
                  mbox64->xferaddr_hi     = 0;

                  return scb;

            case READ_6:
            case WRITE_6:
            case READ_10:
            case WRITE_10:
            case READ_12:
            case WRITE_12:

                  /*
                   * Allocate a SCB and initialize mailbox
                   */
                  if (!(scb = megaraid_alloc_scb(adapter, scp))) {
                        scp->result = (DID_ERROR << 16);
                        *busy = 1;
                        return NULL;
                  }
                  ccb               = (mbox_ccb_t *)scb->ccb;
                  scb->dev_channel  = 0xFF;
                  scb->dev_target         = target;
                  mbox              = ccb->mbox;
                  mbox64                  = ccb->mbox64;
                  mbox->logdrv            = target;

                  /*
                   * A little HACK: 2nd bit is zero for all scsi read
                   * commands and is set for all scsi write commands
                   */
                  mbox->cmd = (scp->cmnd[0] & 0x02) ?  MBOXCMD_LWRITE64:
                              MBOXCMD_LREAD64 ;

                  /*
                   * 6-byte READ(0x08) or WRITE(0x0A) cdb
                   */
                  if (scp->cmd_len == 6) {
                        mbox->numsectors = (uint32_t)scp->cmnd[4];
                        mbox->lba =
                              ((uint32_t)scp->cmnd[1] << 16)      |
                              ((uint32_t)scp->cmnd[2] << 8) |
                              (uint32_t)scp->cmnd[3];

                        mbox->lba &= 0x1FFFFF;
                  }

                  /*
                   * 10-byte READ(0x28) or WRITE(0x2A) cdb
                   */
                  else if (scp->cmd_len == 10) {
                        mbox->numsectors =
                              (uint32_t)scp->cmnd[8] |
                              ((uint32_t)scp->cmnd[7] << 8);
                        mbox->lba =
                              ((uint32_t)scp->cmnd[2] << 24) |
                              ((uint32_t)scp->cmnd[3] << 16) |
                              ((uint32_t)scp->cmnd[4] << 8) |
                              (uint32_t)scp->cmnd[5];
                  }

                  /*
                   * 12-byte READ(0xA8) or WRITE(0xAA) cdb
                   */
                  else if (scp->cmd_len == 12) {
                        mbox->lba =
                              ((uint32_t)scp->cmnd[2] << 24) |
                              ((uint32_t)scp->cmnd[3] << 16) |
                              ((uint32_t)scp->cmnd[4] << 8) |
                              (uint32_t)scp->cmnd[5];

                        mbox->numsectors =
                              ((uint32_t)scp->cmnd[6] << 24) |
                              ((uint32_t)scp->cmnd[7] << 16) |
                              ((uint32_t)scp->cmnd[8] << 8) |
                              (uint32_t)scp->cmnd[9];
                  }
                  else {
                        con_log(CL_ANN, (KERN_WARNING
                              "megaraid: unsupported CDB length\n"));

                        megaraid_dealloc_scb(adapter, scb);

                        scp->result = (DID_ERROR << 16);
                        return NULL;
                  }

                  scb->dma_direction = scp->sc_data_direction;

                  // Calculate Scatter-Gather info
                  mbox64->xferaddr_lo     = (uint32_t )ccb->sgl_dma_h;
                  mbox->numsge            = megaraid_mbox_mksgl(adapter,
                                          scb);
                  mbox->xferaddr          = 0xFFFFFFFF;
                  mbox64->xferaddr_hi     = 0;

                  return scb;

            case RESERVE:
            case RELEASE:
                  /*
                   * Do we support clustering and is the support enabled
                   */
                  if (!adapter->ha) {
                        scp->result = (DID_BAD_TARGET << 16);
                        return NULL;
                  }

                  /*
                   * Allocate a SCB and initialize mailbox
                   */
                  if (!(scb = megaraid_alloc_scb(adapter, scp))) {
                        scp->result = (DID_ERROR << 16);
                        *busy = 1;
                        return NULL;
                  }

                  ccb               = (mbox_ccb_t *)scb->ccb;
                  scb->dev_channel  = 0xFF;
                  scb->dev_target         = target;
                  ccb->raw_mbox[0]  = CLUSTER_CMD;
                  ccb->raw_mbox[2]  =  (scp->cmnd[0] == RESERVE) ?
                                    RESERVE_LD : RELEASE_LD;

                  ccb->raw_mbox[3]  = target;
                  scb->dma_direction      = scp->sc_data_direction;

                  return scb;

            default:
                  scp->result = (DID_BAD_TARGET << 16);
                  return NULL;
            }
      }
      else { // Passthru device commands

            // Do not allow access to target id > 15 or LUN > 7
            if (target > 15 || SCP2LUN(scp) > 7) {
                  scp->result = (DID_BAD_TARGET << 16);
                  return NULL;
            }

            // if fast load option was set and scan for last device is
            // over, reset the fast_load flag so that during a possible
            // next scan, devices can be made available
            if (rdev->fast_load && (target == 15) &&
                  (SCP2CHANNEL(scp) == adapter->max_channel -1)) {

                  con_log(CL_ANN, (KERN_INFO
                  "megaraid[%d]: physical device scan re-enabled\n",
                        adapter->host->host_no));
                  rdev->fast_load = 0;
            }

            /*
             * Display the channel scan for physical devices
             */
            if (!(rdev->last_disp & (1L << SCP2CHANNEL(scp)))) {

                  ss = rdev->fast_load ? skip : scan;

                  con_log(CL_ANN, (KERN_INFO
                        "scsi[%d]: %s scsi channel %d [Phy %d]",
                        adapter->host->host_no, ss, SCP2CHANNEL(scp),
                        channel));

                  con_log(CL_ANN, (
                        " for non-raid devices\n"));

                  rdev->last_disp |= (1L << SCP2CHANNEL(scp));
            }

            // disable channel sweep if fast load option given
            if (rdev->fast_load) {
                  scp->result = (DID_BAD_TARGET << 16);
                  return NULL;
            }

            // Allocate a SCB and initialize passthru
            if (!(scb = megaraid_alloc_scb(adapter, scp))) {
                  scp->result = (DID_ERROR << 16);
                  *busy = 1;
                  return NULL;
            }

            ccb               = (mbox_ccb_t *)scb->ccb;
            scb->dev_channel  = channel;
            scb->dev_target         = target;
            scb->dma_direction      = scp->sc_data_direction;
            mbox              = ccb->mbox;
            mbox64                  = ccb->mbox64;

            // Does this firmware support extended CDBs
            if (adapter->max_cdb_sz == 16) {
                  mbox->cmd         = MBOXCMD_EXTPTHRU;

                  megaraid_mbox_prepare_epthru(adapter, scb, scp);

                  mbox64->xferaddr_lo     = (uint32_t)ccb->epthru_dma_h;
                  mbox64->xferaddr_hi     = 0;
                  mbox->xferaddr          = 0xFFFFFFFF;
            }
            else {
                  mbox->cmd = MBOXCMD_PASSTHRU64;

                  megaraid_mbox_prepare_pthru(adapter, scb, scp);

                  mbox64->xferaddr_lo     = (uint32_t)ccb->pthru_dma_h;
                  mbox64->xferaddr_hi     = 0;
                  mbox->xferaddr          = 0xFFFFFFFF;
            }
            return scb;
      }

      // NOT REACHED
}


/**
 * megaraid_mbox_runpendq - execute commands queued in the pending queue
 * @adapter : controller's soft state
 * @scb_q   : SCB to be queued in the pending list
 *
 * Scan the pending list for commands which are not yet issued and try to
 * post to the controller. The SCB can be a null pointer, which would indicate
 * no SCB to be queue, just try to execute the ones in the pending list.
 *
 * NOTE: We do not actually traverse the pending list. The SCBs are plucked
 * out from the head of the pending list. If it is successfully issued, the
 * next SCB is at the head now.
 */
static void
megaraid_mbox_runpendq(adapter_t *adapter, scb_t *scb_q)
{
      scb_t             *scb;
      unsigned long           flags;

      spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);

      if (scb_q) {
            scb_q->state = SCB_PENDQ;
            list_add_tail(&scb_q->list, &adapter->pend_list);
      }

      // if the adapter in not in quiescent mode, post the commands to FW
      if (adapter->quiescent) {
            spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);
            return;
      }

      while (!list_empty(&adapter->pend_list)) {

            assert_spin_locked(PENDING_LIST_LOCK(adapter));

            scb = list_entry(adapter->pend_list.next, scb_t, list);

            // remove the scb from the pending list and try to
            // issue. If we are unable to issue it, put back in
            // the pending list and return

            list_del_init(&scb->list);

            spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);

            // if mailbox was busy, return SCB back to pending
            // list. Make sure to add at the head, since that's
            // where it would have been removed from

            scb->state = SCB_ISSUED;

            if (mbox_post_cmd(adapter, scb) != 0) {

                  spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);

                  scb->state = SCB_PENDQ;

                  list_add(&scb->list, &adapter->pend_list);

                  spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter),
                        flags);

                  return;
            }

            spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);
      }

      spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);


      return;
}


/**
 * megaraid_mbox_prepare_pthru - prepare a command for physical devices
 * @adapter : pointer to controller's soft state
 * @scb           : scsi control block
 * @scp           : scsi command from the mid-layer
 *
 * Prepare a command for the scsi physical devices.
 */
static void
megaraid_mbox_prepare_pthru(adapter_t *adapter, scb_t *scb,
            struct scsi_cmnd *scp)
{
      mbox_ccb_t        *ccb;
      mraid_passthru_t  *pthru;
      uint8_t                 channel;
      uint8_t                 target;

      ccb   = (mbox_ccb_t *)scb->ccb;
      pthru = ccb->pthru;
      channel     = scb->dev_channel;
      target      = scb->dev_target;

      // 0=6sec, 1=60sec, 2=10min, 3=3hrs, 4=NO timeout
      pthru->timeout          = 4;  
      pthru->ars        = 1;
      pthru->islogical  = 0;
      pthru->channel          = 0;
      pthru->target           = (channel << 4) | target;
      pthru->logdrv           = SCP2LUN(scp);
      pthru->reqsenselen      = 14;
      pthru->cdblen           = scp->cmd_len;

      memcpy(pthru->cdb, scp->cmnd, scp->cmd_len);

      if (scsi_bufflen(scp)) {
            pthru->dataxferlen      = scsi_bufflen(scp);
            pthru->dataxferaddr     = ccb->sgl_dma_h;
            pthru->numsge           = megaraid_mbox_mksgl(adapter, scb);
      }
      else {
            pthru->dataxferaddr     = 0;
            pthru->dataxferlen      = 0;
            pthru->numsge           = 0;
      }
      return;
}


/**
 * megaraid_mbox_prepare_epthru - prepare a command for physical devices
 * @adapter : pointer to controller's soft state
 * @scb           : scsi control block
 * @scp           : scsi command from the mid-layer
 *
 * Prepare a command for the scsi physical devices. This rountine prepares
 * commands for devices which can take extended CDBs (>10 bytes).
 */
static void
megaraid_mbox_prepare_epthru(adapter_t *adapter, scb_t *scb,
            struct scsi_cmnd *scp)
{
      mbox_ccb_t        *ccb;
      mraid_epassthru_t *epthru;
      uint8_t                 channel;
      uint8_t                 target;

      ccb   = (mbox_ccb_t *)scb->ccb;
      epthru      = ccb->epthru;
      channel     = scb->dev_channel;
      target      = scb->dev_target;

      // 0=6sec, 1=60sec, 2=10min, 3=3hrs, 4=NO timeout
      epthru->timeout         = 4;  
      epthru->ars       = 1;
      epthru->islogical = 0;
      epthru->channel         = 0;
      epthru->target          = (channel << 4) | target;
      epthru->logdrv          = SCP2LUN(scp);
      epthru->reqsenselen     = 14;
      epthru->cdblen          = scp->cmd_len;

      memcpy(epthru->cdb, scp->cmnd, scp->cmd_len);

      if (scsi_bufflen(scp)) {
            epthru->dataxferlen     = scsi_bufflen(scp);
            epthru->dataxferaddr    = ccb->sgl_dma_h;
            epthru->numsge          = megaraid_mbox_mksgl(adapter, scb);
      }
      else {
            epthru->dataxferaddr    = 0;
            epthru->dataxferlen     = 0;
            epthru->numsge          = 0;
      }
      return;
}


/**
 * megaraid_ack_sequence - interrupt ack sequence for memory mapped HBAs
 * @adapter : controller's soft state
 *
 * Interrupt acknowledgement sequence for memory mapped HBAs. Find out the
 * completed command and put them on the completed list for later processing.
 *
 * Returns: 1 if the interrupt is valid, 0 otherwise
 */
static int
megaraid_ack_sequence(adapter_t *adapter)
{
      mraid_device_t          *raid_dev = ADAP2RAIDDEV(adapter);
      mbox_t                  *mbox;
      scb_t             *scb;
      uint8_t                 nstatus;
      uint8_t                 completed[MBOX_MAX_FIRMWARE_STATUS];
      struct list_head  clist;
      int               handled;
      uint32_t          dword;
      unsigned long           flags;
      int               i, j;


      mbox  = raid_dev->mbox;

      // move the SCBs from the firmware completed array to our local list
      INIT_LIST_HEAD(&clist);

      // loop till F/W has more commands for us to complete
      handled = 0;
      spin_lock_irqsave(MAILBOX_LOCK(raid_dev), flags);
      do {
            /*
             * Check if a valid interrupt is pending. If found, force the
             * interrupt line low.
             */
            dword = RDOUTDOOR(raid_dev);
            if (dword != 0x10001234) break;

            handled = 1;

            WROUTDOOR(raid_dev, 0x10001234);

            nstatus = 0;
            // wait for valid numstatus to post
            for (i = 0; i < 0xFFFFF; i++) {
                  if (mbox->numstatus != 0xFF) {
                        nstatus = mbox->numstatus;
                        break;
                  }
                  rmb();
            }
            mbox->numstatus = 0xFF;

            adapter->outstanding_cmds -= nstatus;

            for (i = 0; i < nstatus; i++) {

                  // wait for valid command index to post
                  for (j = 0; j < 0xFFFFF; j++) {
                        if (mbox->completed[i] != 0xFF) break;
                        rmb();
                  }
                  completed[i]            = mbox->completed[i];
                  mbox->completed[i]      = 0xFF;

                  if (completed[i] == 0xFF) {
                        con_log(CL_ANN, (KERN_CRIT
                        "megaraid: command posting timed out\n"));

                        BUG();
                        continue;
                  }

                  // Get SCB associated with this command id
                  if (completed[i] >= MBOX_MAX_SCSI_CMDS) {
                        // a cmm command
                        scb = adapter->uscb_list + (completed[i] -
                                    MBOX_MAX_SCSI_CMDS);
                  }
                  else {
                        // an os command
                        scb = adapter->kscb_list + completed[i];
                  }

                  scb->status = mbox->status;
                  list_add_tail(&scb->list, &clist);
            }

            // Acknowledge interrupt
            WRINDOOR(raid_dev, 0x02);

      } while(1);

      spin_unlock_irqrestore(MAILBOX_LOCK(raid_dev), flags);


      // put the completed commands in the completed list. DPC would
      // complete these commands later
      spin_lock_irqsave(COMPLETED_LIST_LOCK(adapter), flags);

      list_splice(&clist, &adapter->completed_list);

      spin_unlock_irqrestore(COMPLETED_LIST_LOCK(adapter), flags);


      // schedule the DPC if there is some work for it
      if (handled)
            tasklet_schedule(&adapter->dpc_h);

      return handled;
}


/**
 * megaraid_isr - isr for memory based mailbox based controllers
 * @irq           : irq
 * @devp    : pointer to our soft state
 *
 * Interrupt service routine for memory-mapped mailbox controllers.
 */
static irqreturn_t
megaraid_isr(int irq, void *devp)
{
      adapter_t   *adapter = devp;
      int         handled;

      handled = megaraid_ack_sequence(adapter);

      /* Loop through any pending requests */
      if (!adapter->quiescent) {
            megaraid_mbox_runpendq(adapter, NULL);
      }

      return IRQ_RETVAL(handled);
}


/**
 * megaraid_mbox_sync_scb - sync kernel buffers
 * @adapter : controller's soft state
 * @scb           : pointer to the resource packet
 *
 * DMA sync if required.
 */
static void
megaraid_mbox_sync_scb(adapter_t *adapter, scb_t *scb)
{
      mbox_ccb_t  *ccb;

      ccb   = (mbox_ccb_t *)scb->ccb;

      if (scb->dma_direction == PCI_DMA_FROMDEVICE)
            pci_dma_sync_sg_for_cpu(adapter->pdev,
                              scsi_sglist(scb->scp),
                              scsi_sg_count(scb->scp),
                              PCI_DMA_FROMDEVICE);

      scsi_dma_unmap(scb->scp);
      return;
}


/**
 * megaraid_mbox_dpc - the tasklet to complete the commands from completed list
 * @devp    : pointer to HBA soft state
 *
 * Pick up the commands from the completed list and send back to the owners.
 * This is a reentrant function and does not assume any locks are held while
 * it is being called.
 */
static void
megaraid_mbox_dpc(unsigned long devp)
{
      adapter_t         *adapter = (adapter_t *)devp;
      mraid_device_t          *raid_dev;
      struct list_head  clist;
      struct scatterlist      *sgl;
      scb_t             *scb;
      scb_t             *tmp;
      struct scsi_cmnd  *scp;
      mraid_passthru_t  *pthru;
      mraid_epassthru_t *epthru;
      mbox_ccb_t        *ccb;
      int               islogical;
      int               pdev_index;
      int               pdev_state;
      mbox_t                  *mbox;
      unsigned long           flags;
      uint8_t                 c;
      int               status;
      uioc_t                  *kioc;


      if (!adapter) return;

      raid_dev = ADAP2RAIDDEV(adapter);

      // move the SCBs from the completed list to our local list
      INIT_LIST_HEAD(&clist);

      spin_lock_irqsave(COMPLETED_LIST_LOCK(adapter), flags);

      list_splice_init(&adapter->completed_list, &clist);

      spin_unlock_irqrestore(COMPLETED_LIST_LOCK(adapter), flags);


      list_for_each_entry_safe(scb, tmp, &clist, list) {

            status            = scb->status;
            scp         = scb->scp;
            ccb         = (mbox_ccb_t *)scb->ccb;
            pthru       = ccb->pthru;
            epthru            = ccb->epthru;
            mbox        = ccb->mbox;

            // Make sure f/w has completed a valid command
            if (scb->state != SCB_ISSUED) {
                  con_log(CL_ANN, (KERN_CRIT
                  "megaraid critical err: invalid command %d:%d:%p\n",
                        scb->sno, scb->state, scp));
                  BUG();
                  continue;   // Must never happen!
            }

            // check for the management command and complete it right away
            if (scb->sno >= MBOX_MAX_SCSI_CMDS) {
                  scb->state  = SCB_FREE;
                  scb->status = status;

                  // remove from local clist
                  list_del_init(&scb->list);

                  kioc              = (uioc_t *)scb->gp;
                  kioc->status            = 0;

                  megaraid_mbox_mm_done(adapter, scb);

                  continue;
            }

            // Was an abort issued for this command earlier
            if (scb->state & SCB_ABORT) {
                  con_log(CL_ANN, (KERN_NOTICE
                  "megaraid: aborted cmd %lx[%x] completed\n",
                        scp->serial_number, scb->sno));
            }

            /*
             * If the inquiry came of a disk drive which is not part of
             * any RAID array, expose it to the kernel. For this to be
             * enabled, user must set the "megaraid_expose_unconf_disks"
             * flag to 1 by specifying it on module parameter list.
             * This would enable data migration off drives from other
             * configurations.
             */
            islogical = MRAID_IS_LOGICAL(adapter, scp);
            if (scp->cmnd[0] == INQUIRY && status == 0 && islogical == 0
                        && IS_RAID_CH(raid_dev, scb->dev_channel)) {

                  sgl = scsi_sglist(scp);
                  if (sg_page(sgl)) {
                        c = *(unsigned char *) sg_virt(&sgl[0]);
                  } else {
                        con_log(CL_ANN, (KERN_WARNING
                                     "megaraid mailbox: invalid sg:%d\n",
                                     __LINE__));
                        c = 0;
                  }

                  if ((c & 0x1F ) == TYPE_DISK) {
                        pdev_index = (scb->dev_channel * 16) +
                              scb->dev_target;
                        pdev_state =
                              raid_dev->pdrv_state[pdev_index] & 0x0F;

                        if (pdev_state == PDRV_ONLINE       ||
                              pdev_state == PDRV_FAILED     ||
                              pdev_state == PDRV_RBLD       ||
                              pdev_state == PDRV_HOTSPARE   ||
                              megaraid_expose_unconf_disks == 0) {

                              status = 0xF0;
                        }
                  }
            }

            // Convert MegaRAID status to Linux error code
            switch (status) {

            case 0x00:

                  scp->result = (DID_OK << 16);
                  break;

            case 0x02:

                  /* set sense_buffer and result fields */
                  if (mbox->cmd == MBOXCMD_PASSTHRU ||
                        mbox->cmd == MBOXCMD_PASSTHRU64) {

                        memcpy(scp->sense_buffer, pthru->reqsensearea,
                                    14);

                        scp->result = DRIVER_SENSE << 24 |
                              DID_OK << 16 | CHECK_CONDITION << 1;
                  }
                  else {
                        if (mbox->cmd == MBOXCMD_EXTPTHRU) {

                              memcpy(scp->sense_buffer,
                                    epthru->reqsensearea, 14);

                              scp->result = DRIVER_SENSE << 24 |
                                    DID_OK << 16 |
                                    CHECK_CONDITION << 1;
                        } else {
                              scp->sense_buffer[0] = 0x70;
                              scp->sense_buffer[2] = ABORTED_COMMAND;
                              scp->result = CHECK_CONDITION << 1;
                        }
                  }
                  break;

            case 0x08:

                  scp->result = DID_BUS_BUSY << 16 | status;
                  break;

            default:

                  /*
                   * If TEST_UNIT_READY fails, we know RESERVATION_STATUS
                   * failed
                   */
                  if (scp->cmnd[0] == TEST_UNIT_READY) {
                        scp->result = DID_ERROR << 16 |
                              RESERVATION_CONFLICT << 1;
                  }
                  else
                  /*
                   * Error code returned is 1 if Reserve or Release
                   * failed or the input parameter is invalid
                   */
                  if (status == 1 && (scp->cmnd[0] == RESERVE ||
                               scp->cmnd[0] == RELEASE)) {

                        scp->result = DID_ERROR << 16 |
                              RESERVATION_CONFLICT << 1;
                  }
                  else {
                        scp->result = DID_BAD_TARGET << 16 | status;
                  }
            }

            // print a debug message for all failed commands
            if (status) {
                  megaraid_mbox_display_scb(adapter, scb);
            }

            // Free our internal resources and call the mid-layer callback
            // routine
            megaraid_mbox_sync_scb(adapter, scb);

            // remove from local clist
            list_del_init(&scb->list);

            // put back in free list
            megaraid_dealloc_scb(adapter, scb);

            // send the scsi packet back to kernel
            scp->scsi_done(scp);
      }

      return;
}


/**
 * megaraid_abort_handler - abort the scsi command
 * @scp           : command to be aborted
 *
 * Abort a previous SCSI request. Only commands on the pending list can be
 * aborted. All the commands issued to the F/W must complete.
 **/
static int
megaraid_abort_handler(struct scsi_cmnd *scp)
{
      adapter_t         *adapter;
      mraid_device_t          *raid_dev;
      scb_t             *scb;
      scb_t             *tmp;
      int               found;
      unsigned long           flags;
      int               i;


      adapter           = SCP2ADAPTER(scp);
      raid_dev    = ADAP2RAIDDEV(adapter);

      con_log(CL_ANN, (KERN_WARNING
            "megaraid: aborting-%ld cmd=%x <c=%d t=%d l=%d>\n",
            scp->serial_number, scp->cmnd[0], SCP2CHANNEL(scp),
            SCP2TARGET(scp), SCP2LUN(scp)));

      // If FW has stopped responding, simply return failure
      if (raid_dev->hw_error) {
            con_log(CL_ANN, (KERN_NOTICE
                  "megaraid: hw error, not aborting\n"));
            return FAILED;
      }

      // There might a race here, where the command was completed by the
      // firmware and now it is on the completed list. Before we could
      // complete the command to the kernel in dpc, the abort came.
      // Find out if this is the case to avoid the race.
      scb = NULL;
      spin_lock_irqsave(COMPLETED_LIST_LOCK(adapter), flags);
      list_for_each_entry_safe(scb, tmp, &adapter->completed_list, list) {

            if (scb->scp == scp) {  // Found command

                  list_del_init(&scb->list);    // from completed list

                  con_log(CL_ANN, (KERN_WARNING
                  "megaraid: %ld:%d[%d:%d], abort from completed list\n",
                        scp->serial_number, scb->sno,
                        scb->dev_channel, scb->dev_target));

                  scp->result = (DID_ABORT << 16);
                  scp->scsi_done(scp);

                  megaraid_dealloc_scb(adapter, scb);

                  spin_unlock_irqrestore(COMPLETED_LIST_LOCK(adapter),
                        flags);

                  return SUCCESS;
            }
      }
      spin_unlock_irqrestore(COMPLETED_LIST_LOCK(adapter), flags);


      // Find out if this command is still on the pending list. If it is and
      // was never issued, abort and return success. If the command is owned
      // by the firmware, we must wait for it to complete by the FW.
      spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);
      list_for_each_entry_safe(scb, tmp, &adapter->pend_list, list) {

            if (scb->scp == scp) {  // Found command

                  list_del_init(&scb->list);    // from pending list

                  ASSERT(!(scb->state & SCB_ISSUED));

                  con_log(CL_ANN, (KERN_WARNING
                        "megaraid abort: %ld[%d:%d], driver owner\n",
                        scp->serial_number, scb->dev_channel,
                        scb->dev_target));

                  scp->result = (DID_ABORT << 16);
                  scp->scsi_done(scp);

                  megaraid_dealloc_scb(adapter, scb);

                  spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter),
                        flags);

                  return SUCCESS;
            }
      }
      spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);


      // Check do we even own this command, in which case this would be
      // owned by the firmware. The only way to locate the FW scb is to
      // traverse through the list of all SCB, since driver does not
      // maintain these SCBs on any list
      found = 0;
      spin_lock_irq(&adapter->lock);
      for (i = 0; i < MBOX_MAX_SCSI_CMDS; i++) {
            scb = adapter->kscb_list + i;

            if (scb->scp == scp) {

                  found = 1;

                  if (!(scb->state & SCB_ISSUED)) {
                        con_log(CL_ANN, (KERN_WARNING
                        "megaraid abort: %ld%d[%d:%d], invalid state\n",
                        scp->serial_number, scb->sno, scb->dev_channel,
                        scb->dev_target));
                        BUG();
                  }
                  else {
                        con_log(CL_ANN, (KERN_WARNING
                        "megaraid abort: %ld:%d[%d:%d], fw owner\n",
                        scp->serial_number, scb->sno, scb->dev_channel,
                        scb->dev_target));
                  }
            }
      }
      spin_unlock_irq(&adapter->lock);

      if (!found) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid abort: scsi cmd:%ld, do now own\n",
                  scp->serial_number));

            // FIXME: Should there be a callback for this command?
            return SUCCESS;
      }

      // We cannot actually abort a command owned by firmware, return
      // failure and wait for reset. In host reset handler, we will find out
      // if the HBA is still live
      return FAILED;
}

/**
 * megaraid_reset_handler - device reset hadler for mailbox based driver
 * @scp           : reference command
 *
 * Reset handler for the mailbox based controller. First try to find out if
 * the FW is still live, in which case the outstanding commands counter mut go
 * down to 0. If that happens, also issue the reservation reset command to
 * relinquish (possible) reservations on the logical drives connected to this
 * host.
 **/
static int
megaraid_reset_handler(struct scsi_cmnd *scp)
{
      adapter_t   *adapter;
      scb_t       *scb;
      scb_t       *tmp;
      mraid_device_t    *raid_dev;
      unsigned long     flags;
      uint8_t           raw_mbox[sizeof(mbox_t)];
      int         rval;
      int         recovery_window;
      int         recovering;
      int         i;
      uioc_t            *kioc;

      adapter           = SCP2ADAPTER(scp);
      raid_dev    = ADAP2RAIDDEV(adapter);

      // return failure if adapter is not responding
      if (raid_dev->hw_error) {
            con_log(CL_ANN, (KERN_NOTICE
                  "megaraid: hw error, cannot reset\n"));
            return FAILED;
      }


      // Under exceptional conditions, FW can take up to 3 minutes to
      // complete command processing. Wait for additional 2 minutes for the
      // pending commands counter to go down to 0. If it doesn't, let the
      // controller be marked offline
      // Also, reset all the commands currently owned by the driver
      spin_lock_irqsave(PENDING_LIST_LOCK(adapter), flags);
      list_for_each_entry_safe(scb, tmp, &adapter->pend_list, list) {
            list_del_init(&scb->list);    // from pending list

            if (scb->sno >= MBOX_MAX_SCSI_CMDS) {
                  con_log(CL_ANN, (KERN_WARNING
                  "megaraid: IOCTL packet with %d[%d:%d] being reset\n",
                  scb->sno, scb->dev_channel, scb->dev_target));

                  scb->status = -1;

                  kioc              = (uioc_t *)scb->gp;
                  kioc->status            = -EFAULT;

                  megaraid_mbox_mm_done(adapter, scb);
            } else {
                  if (scb->scp == scp) {  // Found command
                        con_log(CL_ANN, (KERN_WARNING
                              "megaraid: %ld:%d[%d:%d], reset from pending list\n",
                              scp->serial_number, scb->sno,
                              scb->dev_channel, scb->dev_target));
                  } else {
                        con_log(CL_ANN, (KERN_WARNING
                        "megaraid: IO packet with %d[%d:%d] being reset\n",
                        scb->sno, scb->dev_channel, scb->dev_target));
                  }

                  scb->scp->result = (DID_RESET << 16);
                  scb->scp->scsi_done(scb->scp);

                  megaraid_dealloc_scb(adapter, scb);
            }
      }
      spin_unlock_irqrestore(PENDING_LIST_LOCK(adapter), flags);

      if (adapter->outstanding_cmds) {
            con_log(CL_ANN, (KERN_NOTICE
                  "megaraid: %d outstanding commands. Max wait %d sec\n",
                  adapter->outstanding_cmds,
                  (MBOX_RESET_WAIT + MBOX_RESET_EXT_WAIT)));
      }

      recovery_window = MBOX_RESET_WAIT + MBOX_RESET_EXT_WAIT;

      recovering = adapter->outstanding_cmds;

      for (i = 0; i < recovery_window; i++) {

            megaraid_ack_sequence(adapter);

            // print a message once every 5 seconds only
            if (!(i % 5)) {
                  con_log(CL_ANN, (
                  "megaraid mbox: Wait for %d commands to complete:%d\n",
                        adapter->outstanding_cmds,
                        (MBOX_RESET_WAIT + MBOX_RESET_EXT_WAIT) - i));
            }

            // bailout if no recovery happended in reset time
            if (adapter->outstanding_cmds == 0) {
                  break;
            }

            msleep(1000);
      }

      spin_lock(&adapter->lock);

      // If still outstanding commands, bail out
      if (adapter->outstanding_cmds) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid mbox: critical hardware error!\n"));

            raid_dev->hw_error = 1;

            rval = FAILED;
            goto out;
      }
      else {
            con_log(CL_ANN, (KERN_NOTICE
            "megaraid mbox: reset sequence completed sucessfully\n"));
      }


      // If the controller supports clustering, reset reservations
      if (!adapter->ha) {
            rval = SUCCESS;
            goto out;
      }

      // clear reservations if any
      raw_mbox[0] = CLUSTER_CMD;
      raw_mbox[2] = RESET_RESERVATIONS;

      rval = SUCCESS;
      if (mbox_post_sync_cmd_fast(adapter, raw_mbox) == 0) {
            con_log(CL_ANN,
                  (KERN_INFO "megaraid: reservation reset\n"));
      }
      else {
            rval = FAILED;
            con_log(CL_ANN, (KERN_WARNING
                        "megaraid: reservation reset failed\n"));
      }

 out:
      spin_unlock_irq(&adapter->lock);
      return rval;
}

/*
 * START: internal commands library
 *
 * This section of the driver has the common routine used by the driver and
 * also has all the FW routines
 */

/**
 * mbox_post_sync_cmd() - blocking command to the mailbox based controllers
 * @adapter : controller's soft state
 * @raw_mbox      : the mailbox
 *
 * Issue a scb in synchronous and non-interrupt mode for mailbox based
 * controllers.
 */
static int
mbox_post_sync_cmd(adapter_t *adapter, uint8_t raw_mbox[])
{
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);
      mbox64_t    *mbox64;
      mbox_t            *mbox;
      uint8_t           status;
      int         i;


      mbox64      = raid_dev->mbox64;
      mbox  = raid_dev->mbox;

      /*
       * Wait until mailbox is free
       */
      if (megaraid_busywait_mbox(raid_dev) != 0)
            goto blocked_mailbox;

      /*
       * Copy mailbox data into host structure
       */
      memcpy((caddr_t)mbox, (caddr_t)raw_mbox, 16);
      mbox->cmdid       = 0xFE;
      mbox->busy        = 1;
      mbox->poll        = 0;
      mbox->ack         = 0;
      mbox->numstatus         = 0xFF;
      mbox->status            = 0xFF;

      wmb();
      WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);

      // wait for maximum 1 second for status to post. If the status is not
      // available within 1 second, assume FW is initializing and wait
      // for an extended amount of time
      if (mbox->numstatus == 0xFF) {      // status not yet available
            udelay(25);

            for (i = 0; mbox->numstatus == 0xFF && i < 1000; i++) {
                  rmb();
                  msleep(1);
            }


            if (i == 1000) {
                  con_log(CL_ANN, (KERN_NOTICE
                        "megaraid mailbox: wait for FW to boot      "));

                  for (i = 0; (mbox->numstatus == 0xFF) &&
                              (i < MBOX_RESET_WAIT); i++) {
                        rmb();
                        con_log(CL_ANN, ("\b\b\b\b\b[%03d]",
                                          MBOX_RESET_WAIT - i));
                        msleep(1000);
                  }

                  if (i == MBOX_RESET_WAIT) {

                        con_log(CL_ANN, (
                        "\nmegaraid mailbox: status not available\n"));

                        return -1;
                  }
                  con_log(CL_ANN, ("\b\b\b\b\b[ok] \n"));
            }
      }

      // wait for maximum 1 second for poll semaphore
      if (mbox->poll != 0x77) {
            udelay(25);

            for (i = 0; (mbox->poll != 0x77) && (i < 1000); i++) {
                  rmb();
                  msleep(1);
            }

            if (i == 1000) {
                  con_log(CL_ANN, (KERN_WARNING
                  "megaraid mailbox: could not get poll semaphore\n"));
                  return -1;
            }
      }

      WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x2);
      wmb();

      // wait for maximum 1 second for acknowledgement
      if (RDINDOOR(raid_dev) & 0x2) {
            udelay(25);

            for (i = 0; (RDINDOOR(raid_dev) & 0x2) && (i < 1000); i++) {
                  rmb();
                  msleep(1);
            }

            if (i == 1000) {
                  con_log(CL_ANN, (KERN_WARNING
                        "megaraid mailbox: could not acknowledge\n"));
                  return -1;
            }
      }
      mbox->poll  = 0;
      mbox->ack   = 0x77;

      status = mbox->status;

      // invalidate the completed command id array. After command
      // completion, firmware would write the valid id.
      mbox->numstatus   = 0xFF;
      mbox->status      = 0xFF;
      for (i = 0; i < MBOX_MAX_FIRMWARE_STATUS; i++) {
            mbox->completed[i] = 0xFF;
      }

      return status;

blocked_mailbox:

      con_log(CL_ANN, (KERN_WARNING "megaraid: blocked mailbox\n") );
      return -1;
}


/**
 * mbox_post_sync_cmd_fast - blocking command to the mailbox based controllers
 * @adapter : controller's soft state
 * @raw_mbox      : the mailbox
 *
 * Issue a scb in synchronous and non-interrupt mode for mailbox based
 * controllers. This is a faster version of the synchronous command and
 * therefore can be called in interrupt-context as well.
 */
static int
mbox_post_sync_cmd_fast(adapter_t *adapter, uint8_t raw_mbox[])
{
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);
      mbox_t            *mbox;
      long        i;


      mbox  = raid_dev->mbox;

      // return immediately if the mailbox is busy
      if (mbox->busy) return -1;

      // Copy mailbox data into host structure
      memcpy((caddr_t)mbox, (caddr_t)raw_mbox, 14);
      mbox->cmdid       = 0xFE;
      mbox->busy        = 1;
      mbox->poll        = 0;
      mbox->ack         = 0;
      mbox->numstatus         = 0xFF;
      mbox->status            = 0xFF;

      wmb();
      WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);

      for (i = 0; i < MBOX_SYNC_WAIT_CNT; i++) {
            if (mbox->numstatus != 0xFF) break;
            rmb();
            udelay(MBOX_SYNC_DELAY_200);
      }

      if (i == MBOX_SYNC_WAIT_CNT) {
            // We may need to re-calibrate the counter
            con_log(CL_ANN, (KERN_CRIT
                  "megaraid: fast sync command timed out\n"));
      }

      WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x2);
      wmb();

      return mbox->status;
}


/**
 * megaraid_busywait_mbox() - Wait until the controller's mailbox is available
 * @raid_dev      : RAID device (HBA) soft state
 *
 * Wait until the controller's mailbox is available to accept more commands.
 * Wait for at most 1 second.
 */
static int
megaraid_busywait_mbox(mraid_device_t *raid_dev)
{
      mbox_t      *mbox = raid_dev->mbox;
      int   i = 0;

      if (mbox->busy) {
            udelay(25);
            for (i = 0; mbox->busy && i < 1000; i++)
                  msleep(1);
      }

      if (i < 1000) return 0;
      else return -1;
}


/**
 * megaraid_mbox_product_info - some static information about the controller
 * @adapter : our soft state
 *
 * Issue commands to the controller to grab some parameters required by our
 * caller.
 */
static int
megaraid_mbox_product_info(adapter_t *adapter)
{
      mraid_device_t          *raid_dev = ADAP2RAIDDEV(adapter);
      mbox_t                  *mbox;
      uint8_t                 raw_mbox[sizeof(mbox_t)];
      mraid_pinfo_t           *pinfo;
      dma_addr_t        pinfo_dma_h;
      mraid_inquiry3_t  *mraid_inq3;
      int               i;


      memset((caddr_t)raw_mbox, 0, sizeof(raw_mbox));
      mbox = (mbox_t *)raw_mbox;

      /*
       * Issue an ENQUIRY3 command to find out certain adapter parameters,
       * e.g., max channels, max commands etc.
       */
      pinfo = pci_alloc_consistent(adapter->pdev, sizeof(mraid_pinfo_t),
                  &pinfo_dma_h);

      if (pinfo == NULL) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: out of memory, %s %d\n", __func__,
                  __LINE__));

            return -1;
      }
      memset(pinfo, 0, sizeof(mraid_pinfo_t));

      mbox->xferaddr = (uint32_t)adapter->ibuf_dma_h;
      memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);

      raw_mbox[0] = FC_NEW_CONFIG;
      raw_mbox[2] = NC_SUBOP_ENQUIRY3;
      raw_mbox[3] = ENQ3_GET_SOLICITED_FULL;

      // Issue the command
      if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {

            con_log(CL_ANN, (KERN_WARNING "megaraid: Inquiry3 failed\n"));

            pci_free_consistent(adapter->pdev, sizeof(mraid_pinfo_t),
                  pinfo, pinfo_dma_h);

            return -1;
      }

      /*
       * Collect information about state of each physical drive
       * attached to the controller. We will expose all the disks
       * which are not part of RAID
       */
      mraid_inq3 = (mraid_inquiry3_t *)adapter->ibuf;
      for (i = 0; i < MBOX_MAX_PHYSICAL_DRIVES; i++) {
            raid_dev->pdrv_state[i] = mraid_inq3->pdrv_state[i];
      }

      /*
       * Get product info for information like number of channels,
       * maximum commands supported.
       */
      memset((caddr_t)raw_mbox, 0, sizeof(raw_mbox));
      mbox->xferaddr = (uint32_t)pinfo_dma_h;

      raw_mbox[0] = FC_NEW_CONFIG;
      raw_mbox[2] = NC_SUBOP_PRODUCT_INFO;

      if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: product info failed\n"));

            pci_free_consistent(adapter->pdev, sizeof(mraid_pinfo_t),
                  pinfo, pinfo_dma_h);

            return -1;
      }

      /*
       * Setup some parameters for host, as required by our caller
       */
      adapter->max_channel = pinfo->nchannels;

      /*
       * we will export all the logical drives on a single channel.
       * Add 1 since inquires do not come for inititor ID
       */
      adapter->max_target     = MAX_LOGICAL_DRIVES_40LD + 1;
      adapter->max_lun  = 8;  // up to 8 LUNs for non-disk devices

      /*
       * These are the maximum outstanding commands for the scsi-layer
       */
      adapter->max_cmds = MBOX_MAX_SCSI_CMDS;

      memset(adapter->fw_version, 0, VERSION_SIZE);
      memset(adapter->bios_version, 0, VERSION_SIZE);

      memcpy(adapter->fw_version, pinfo->fw_version, 4);
      adapter->fw_version[4] = 0;

      memcpy(adapter->bios_version, pinfo->bios_version, 4);
      adapter->bios_version[4] = 0;

      con_log(CL_ANN, (KERN_NOTICE
            "megaraid: fw version:[%s] bios version:[%s]\n",
            adapter->fw_version, adapter->bios_version));

      pci_free_consistent(adapter->pdev, sizeof(mraid_pinfo_t), pinfo,
                  pinfo_dma_h);

      return 0;
}



/**
 * megaraid_mbox_extended_cdb - check for support for extended CDBs
 * @adapter : soft state for the controller
 *
 * This routine check whether the controller in question supports extended
 * ( > 10 bytes ) CDBs.
 */
static int
megaraid_mbox_extended_cdb(adapter_t *adapter)
{
      mbox_t            *mbox;
      uint8_t           raw_mbox[sizeof(mbox_t)];
      int         rval;

      mbox = (mbox_t *)raw_mbox;

      memset((caddr_t)raw_mbox, 0, sizeof(raw_mbox));
      mbox->xferaddr    = (uint32_t)adapter->ibuf_dma_h;

      memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);

      raw_mbox[0] = MAIN_MISC_OPCODE;
      raw_mbox[2] = SUPPORT_EXT_CDB;

      /*
       * Issue the command
       */
      rval = 0;
      if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {
            rval = -1;
      }

      return rval;
}


/**
 * megaraid_mbox_support_ha - Do we support clustering
 * @adapter : soft state for the controller
 * @init_id : ID of the initiator
 *
 * Determine if the firmware supports clustering and the ID of the initiator.
 */
static int
megaraid_mbox_support_ha(adapter_t *adapter, uint16_t *init_id)
{
      mbox_t            *mbox;
      uint8_t           raw_mbox[sizeof(mbox_t)];
      int         rval;


      mbox = (mbox_t *)raw_mbox;

      memset((caddr_t)raw_mbox, 0, sizeof(raw_mbox));

      mbox->xferaddr = (uint32_t)adapter->ibuf_dma_h;

      memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);

      raw_mbox[0] = GET_TARGET_ID;

      // Issue the command
      *init_id = 7;
      rval =  -1;
      if (mbox_post_sync_cmd(adapter, raw_mbox) == 0) {

            *init_id = *(uint8_t *)adapter->ibuf;

            con_log(CL_ANN, (KERN_INFO
                  "megaraid: cluster firmware, initiator ID: %d\n",
                  *init_id));

            rval =  0;
      }

      return rval;
}


/**
 * megaraid_mbox_support_random_del - Do we support random deletion
 * @adapter : soft state for the controller
 *
 * Determine if the firmware supports random deletion.
 * Return:  1 is operation supported, 0 otherwise
 */
static int
megaraid_mbox_support_random_del(adapter_t *adapter)
{
      mbox_t            *mbox;
      uint8_t           raw_mbox[sizeof(mbox_t)];
      int         rval;

      /*
       * Newer firmware on Dell CERC expect a different
       * random deletion handling, so disable it.
       */
      if (adapter->pdev->vendor == PCI_VENDOR_ID_AMI &&
          adapter->pdev->device == PCI_DEVICE_ID_AMI_MEGARAID3 &&
          adapter->pdev->subsystem_vendor == PCI_VENDOR_ID_DELL &&
          adapter->pdev->subsystem_device == PCI_SUBSYS_ID_CERC_ATA100_4CH &&
          (adapter->fw_version[0] > '6' ||
           (adapter->fw_version[0] == '6' &&
            adapter->fw_version[2] > '6') ||
           (adapter->fw_version[0] == '6'
            && adapter->fw_version[2] == '6'
            && adapter->fw_version[3] > '1'))) {
            con_log(CL_DLEVEL1, ("megaraid: disable random deletion\n"));
            return 0;
      }

      mbox = (mbox_t *)raw_mbox;

      memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));

      raw_mbox[0] = FC_DEL_LOGDRV;
      raw_mbox[2] = OP_SUP_DEL_LOGDRV;

      // Issue the command
      rval = 0;
      if (mbox_post_sync_cmd(adapter, raw_mbox) == 0) {

            con_log(CL_DLEVEL1, ("megaraid: supports random deletion\n"));

            rval =  1;
      }

      return rval;
}


/**
 * megaraid_mbox_get_max_sg - maximum sg elements supported by the firmware
 * @adapter : soft state for the controller
 *
 * Find out the maximum number of scatter-gather elements supported by the
 * firmware.
 */
static int
megaraid_mbox_get_max_sg(adapter_t *adapter)
{
      mbox_t            *mbox;
      uint8_t           raw_mbox[sizeof(mbox_t)];
      int         nsg;


      mbox = (mbox_t *)raw_mbox;

      memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));

      mbox->xferaddr = (uint32_t)adapter->ibuf_dma_h;

      memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);

      raw_mbox[0] = MAIN_MISC_OPCODE;
      raw_mbox[2] = GET_MAX_SG_SUPPORT;

      // Issue the command
      if (mbox_post_sync_cmd(adapter, raw_mbox) == 0) {
            nsg =  *(uint8_t *)adapter->ibuf;
      }
      else {
            nsg =  MBOX_DEFAULT_SG_SIZE;
      }

      if (nsg > MBOX_MAX_SG_SIZE) nsg = MBOX_MAX_SG_SIZE;

      return nsg;
}


/**
 * megaraid_mbox_enum_raid_scsi - enumerate the RAID and SCSI channels
 * @adapter : soft state for the controller
 *
 * Enumerate the RAID and SCSI channels for ROMB platforms so that channels
 * can be exported as regular SCSI channels.
 */
static void
megaraid_mbox_enum_raid_scsi(adapter_t *adapter)
{
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);
      mbox_t            *mbox;
      uint8_t           raw_mbox[sizeof(mbox_t)];


      mbox = (mbox_t *)raw_mbox;

      memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));

      mbox->xferaddr = (uint32_t)adapter->ibuf_dma_h;

      memset((void *)adapter->ibuf, 0, MBOX_IBUF_SIZE);

      raw_mbox[0] = CHNL_CLASS;
      raw_mbox[2] = GET_CHNL_CLASS;

      // Issue the command. If the command fails, all channels are RAID
      // channels
      raid_dev->channel_class = 0xFF;
      if (mbox_post_sync_cmd(adapter, raw_mbox) == 0) {
            raid_dev->channel_class =  *(uint8_t *)adapter->ibuf;
      }

      return;
}


/**
 * megaraid_mbox_flush_cache - flush adapter and disks cache
 * @adapter       : soft state for the controller
 *
 * Flush adapter cache followed by disks cache.
 */
static void
megaraid_mbox_flush_cache(adapter_t *adapter)
{
      mbox_t      *mbox;
      uint8_t     raw_mbox[sizeof(mbox_t)];


      mbox = (mbox_t *)raw_mbox;

      memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));

      raw_mbox[0] = FLUSH_ADAPTER;

      if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {
            con_log(CL_ANN, ("megaraid: flush adapter failed\n"));
      }

      raw_mbox[0] = FLUSH_SYSTEM;

      if (mbox_post_sync_cmd(adapter, raw_mbox) != 0) {
            con_log(CL_ANN, ("megaraid: flush disks cache failed\n"));
      }

      return;
}


/**
 * megaraid_mbox_fire_sync_cmd - fire the sync cmd
 * @adapter       : soft state for the controller
 *
 * Clears the pending cmds in FW and reinits its RAID structs.
 */
static int
megaraid_mbox_fire_sync_cmd(adapter_t *adapter)
{
      mbox_t      *mbox;
      uint8_t     raw_mbox[sizeof(mbox_t)];
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);
      mbox64_t *mbox64;
      int   status = 0;
      int i;
      uint32_t dword;

      mbox = (mbox_t *)raw_mbox;

      memset((caddr_t)raw_mbox, 0, sizeof(mbox_t));

      raw_mbox[0] = 0xFF;

      mbox64      = raid_dev->mbox64;
      mbox  = raid_dev->mbox;

      /* Wait until mailbox is free */
      if (megaraid_busywait_mbox(raid_dev) != 0) {
            status = 1;
            goto blocked_mailbox;
      }

      /* Copy mailbox data into host structure */
      memcpy((caddr_t)mbox, (caddr_t)raw_mbox, 16);
      mbox->cmdid       = 0xFE;
      mbox->busy        = 1;
      mbox->poll        = 0;
      mbox->ack         = 0;
      mbox->numstatus         = 0;
      mbox->status            = 0;

      wmb();
      WRINDOOR(raid_dev, raid_dev->mbox_dma | 0x1);

      /* Wait for maximum 1 min for status to post.
       * If the Firmware SUPPORTS the ABOVE COMMAND,
       * mbox->cmd will be set to 0
       * else
       * the firmware will reject the command with
       * mbox->numstatus set to 1
       */

      i = 0;
      status = 0;
      while (!mbox->numstatus && mbox->cmd == 0xFF) {
            rmb();
            msleep(1);
            i++;
            if (i > 1000 * 60) {
                  status = 1;
                  break;
            }
      }
      if (mbox->numstatus == 1)
            status = 1; /*cmd not supported*/

      /* Check for interrupt line */
      dword = RDOUTDOOR(raid_dev);
      WROUTDOOR(raid_dev, dword);
      WRINDOOR(raid_dev,2);

      return status;

blocked_mailbox:
      con_log(CL_ANN, (KERN_WARNING "megaraid: blocked mailbox\n"));
      return status;
}

/**
 * megaraid_mbox_display_scb - display SCB information, mostly debug purposes
 * @adapter       : controller's soft state
 * @scb                 : SCB to be displayed
 * @level         : debug level for console print
 *
 * Diplay information about the given SCB iff the current debug level is
 * verbose.
 */
static void
megaraid_mbox_display_scb(adapter_t *adapter, scb_t *scb)
{
      mbox_ccb_t        *ccb;
      struct scsi_cmnd  *scp;
      mbox_t                  *mbox;
      int               level;
      int               i;


      ccb   = (mbox_ccb_t *)scb->ccb;
      scp   = scb->scp;
      mbox  = ccb->mbox;

      level = CL_DLEVEL3;

      con_log(level, (KERN_NOTICE
            "megaraid mailbox: status:%#x cmd:%#x id:%#x ", scb->status,
            mbox->cmd, scb->sno));

      con_log(level, ("sec:%#x lba:%#x addr:%#x ld:%d sg:%d\n",
            mbox->numsectors, mbox->lba, mbox->xferaddr, mbox->logdrv,
            mbox->numsge));

      if (!scp) return;

      con_log(level, (KERN_NOTICE "scsi cmnd: "));

      for (i = 0; i < scp->cmd_len; i++) {
            con_log(level, ("%#2.02x ", scp->cmnd[i]));
      }

      con_log(level, ("\n"));

      return;
}


/**
 * megaraid_mbox_setup_device_map - manage device ids
 * @adapter : Driver's soft state
 *
 * Manange the device ids to have an appropraite mapping between the kernel
 * scsi addresses and megaraid scsi and logical drive addresses. We export
 * scsi devices on their actual addresses, whereas the logical drives are
 * exported on a virtual scsi channel.
 */
static void
megaraid_mbox_setup_device_map(adapter_t *adapter)
{
      uint8_t           c;
      uint8_t           t;

      /*
       * First fill the values on the logical drive channel
       */
      for (t = 0; t < LSI_MAX_LOGICAL_DRIVES_64LD; t++)
            adapter->device_ids[adapter->max_channel][t] =
                  (t < adapter->init_id) ?  t : t - 1;

      adapter->device_ids[adapter->max_channel][adapter->init_id] = 0xFF;

      /*
       * Fill the values on the physical devices channels
       */
      for (c = 0; c < adapter->max_channel; c++)
            for (t = 0; t < LSI_MAX_LOGICAL_DRIVES_64LD; t++)
                  adapter->device_ids[c][t] = (c << 8) | t;
}


/*
 * END: internal commands library
 */

/*
 * START: Interface for the common management module
 *
 * This is the module, which interfaces with the common management module to
 * provide support for ioctl and sysfs
 */

/**
 * megaraid_cmm_register - register with the management module
 * @adapter       : HBA soft state
 *
 * Register with the management module, which allows applications to issue
 * ioctl calls to the drivers. This interface is used by the management module
 * to setup sysfs support as well.
 */
static int
megaraid_cmm_register(adapter_t *adapter)
{
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);
      mraid_mmadp_t     adp;
      scb_t       *scb;
      mbox_ccb_t  *ccb;
      int         rval;
      int         i;

      // Allocate memory for the base list of scb for management module.
      adapter->uscb_list = kcalloc(MBOX_MAX_USER_CMDS, sizeof(scb_t), GFP_KERNEL);

      if (adapter->uscb_list == NULL) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: out of memory, %s %d\n", __func__,
                  __LINE__));
            return -1;
      }


      // Initialize the synchronization parameters for resources for
      // commands for management module
      INIT_LIST_HEAD(&adapter->uscb_pool);

      spin_lock_init(USER_FREE_LIST_LOCK(adapter));



      // link all the packets. Note, CCB for commands, coming from the
      // commom management module, mailbox physical address are already
      // setup by it. We just need placeholder for that in our local command
      // control blocks
      for (i = 0; i < MBOX_MAX_USER_CMDS; i++) {

            scb               = adapter->uscb_list + i;
            ccb               = raid_dev->uccb_list + i;

            scb->ccb          = (caddr_t)ccb;
            ccb->mbox64       = raid_dev->umbox64 + i;
            ccb->mbox         = &ccb->mbox64->mbox32;
            ccb->raw_mbox           = (uint8_t *)ccb->mbox;

            scb->gp                 = 0;

            // COMMAND ID 0 - (MBOX_MAX_SCSI_CMDS-1) ARE RESERVED FOR
            // COMMANDS COMING FROM IO SUBSYSTEM (MID-LAYER)
            scb->sno          = i + MBOX_MAX_SCSI_CMDS;

            scb->scp          = NULL;
            scb->state        = SCB_FREE;
            scb->dma_direction      = PCI_DMA_NONE;
            scb->dma_type           = MRAID_DMA_NONE;
            scb->dev_channel  = -1;
            scb->dev_target         = -1;

            // put scb in the free pool
            list_add_tail(&scb->list, &adapter->uscb_pool);
      }

      adp.unique_id           = adapter->unique_id;
      adp.drvr_type           = DRVRTYPE_MBOX;
      adp.drvr_data           = (unsigned long)adapter;
      adp.pdev          = adapter->pdev;
      adp.issue_uioc          = megaraid_mbox_mm_handler;
      adp.timeout       = MBOX_RESET_WAIT + MBOX_RESET_EXT_WAIT;
      adp.max_kioc            = MBOX_MAX_USER_CMDS;

      if ((rval = mraid_mm_register_adp(&adp)) != 0) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid mbox: did not register with CMM\n"));

            kfree(adapter->uscb_list);
      }

      return rval;
}


/**
 * megaraid_cmm_unregister - un-register with the management module
 * @adapter       : HBA soft state
 *
 * Un-register with the management module.
 * FIXME: mgmt module must return failure for unregister if it has pending
 * commands in LLD.
 */
static int
megaraid_cmm_unregister(adapter_t *adapter)
{
      kfree(adapter->uscb_list);
      mraid_mm_unregister_adp(adapter->unique_id);
      return 0;
}


/**
 * megaraid_mbox_mm_handler - interface for CMM to issue commands to LLD
 * @drvr_data           : LLD specific data
 * @kioc          : CMM interface packet
 * @action        : command action
 *
 * This routine is invoked whenever the Common Management Module (CMM) has a
 * command for us. The 'action' parameter specifies if this is a new command
 * or otherwise.
 */
static int
megaraid_mbox_mm_handler(unsigned long drvr_data, uioc_t *kioc, uint32_t action)
{
      adapter_t *adapter;

      if (action != IOCTL_ISSUE) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: unsupported management action:%#2x\n",
                  action));
            return (-ENOTSUPP);
      }

      adapter = (adapter_t *)drvr_data;

      // make sure this adapter is not being detached right now.
      if (atomic_read(&adapter->being_detached)) {
            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: reject management request, detaching\n"));
            return (-ENODEV);
      }

      switch (kioc->opcode) {

      case GET_ADAP_INFO:

            kioc->status =  gather_hbainfo(adapter, (mraid_hba_info_t *)
                              (unsigned long)kioc->buf_vaddr);

            kioc->done(kioc);

            return kioc->status;

      case MBOX_CMD:

            return megaraid_mbox_mm_command(adapter, kioc);

      default:
            kioc->status = (-EINVAL);
            kioc->done(kioc);
            return (-EINVAL);
      }

      return 0;   // not reached
}

/**
 * megaraid_mbox_mm_command - issues commands routed through CMM
 * @adapter       : HBA soft state
 * @kioc          : management command packet
 *
 * Issues commands, which are routed through the management module.
 */
static int
megaraid_mbox_mm_command(adapter_t *adapter, uioc_t *kioc)
{
      struct list_head  *head = &adapter->uscb_pool;
      mbox64_t          *mbox64;
      uint8_t                 *raw_mbox;
      scb_t             *scb;
      mbox_ccb_t        *ccb;
      unsigned long           flags;

      // detach one scb from free pool
      spin_lock_irqsave(USER_FREE_LIST_LOCK(adapter), flags);

      if (list_empty(head)) { // should never happen because of CMM

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid mbox: bug in cmm handler, lost resources\n"));

            spin_unlock_irqrestore(USER_FREE_LIST_LOCK(adapter), flags);

            return (-EINVAL);
      }

      scb = list_entry(head->next, scb_t, list);
      list_del_init(&scb->list);

      spin_unlock_irqrestore(USER_FREE_LIST_LOCK(adapter), flags);

      scb->state        = SCB_ACTIVE;
      scb->dma_type           = MRAID_DMA_NONE;
      scb->dma_direction      = PCI_DMA_NONE;

      ccb         = (mbox_ccb_t *)scb->ccb;
      mbox64            = (mbox64_t *)(unsigned long)kioc->cmdbuf;
      raw_mbox    = (uint8_t *)&mbox64->mbox32;

      memcpy(ccb->mbox64, mbox64, sizeof(mbox64_t));

      scb->gp           = (unsigned long)kioc;

      /*
       * If it is a logdrv random delete operation, we have to wait till
       * there are no outstanding cmds at the fw and then issue it directly
       */
      if (raw_mbox[0] == FC_DEL_LOGDRV && raw_mbox[2] == OP_DEL_LOGDRV) {

            if (wait_till_fw_empty(adapter)) {
                  con_log(CL_ANN, (KERN_NOTICE
                        "megaraid mbox: LD delete, timed out\n"));

                  kioc->status = -ETIME;

                  scb->status = -1;

                  megaraid_mbox_mm_done(adapter, scb);

                  return (-ETIME);
            }

            INIT_LIST_HEAD(&scb->list);

            scb->state = SCB_ISSUED;
            if (mbox_post_cmd(adapter, scb) != 0) {

                  con_log(CL_ANN, (KERN_NOTICE
                        "megaraid mbox: LD delete, mailbox busy\n"));

                  kioc->status = -EBUSY;

                  scb->status = -1;

                  megaraid_mbox_mm_done(adapter, scb);

                  return (-EBUSY);
            }

            return 0;
      }

      // put the command on the pending list and execute
      megaraid_mbox_runpendq(adapter, scb);

      return 0;
}


static int
wait_till_fw_empty(adapter_t *adapter)
{
      unsigned long     flags = 0;
      int         i;


      /*
       * Set the quiescent flag to stop issuing cmds to FW.
       */
      spin_lock_irqsave(&adapter->lock, flags);
      adapter->quiescent++;
      spin_unlock_irqrestore(&adapter->lock, flags);

      /*
       * Wait till there are no more cmds outstanding at FW. Try for at most
       * 60 seconds
       */
      for (i = 0; i < 60 && adapter->outstanding_cmds; i++) {
            con_log(CL_DLEVEL1, (KERN_INFO
                  "megaraid: FW has %d pending commands\n",
                  adapter->outstanding_cmds));

            msleep(1000);
      }

      return adapter->outstanding_cmds;
}


/**
 * megaraid_mbox_mm_done - callback for CMM commands
 * @adapter : HBA soft state
 * @scb           : completed command
 *
 * Callback routine for internal commands originated from the management
 * module.
 */
static void
megaraid_mbox_mm_done(adapter_t *adapter, scb_t *scb)
{
      uioc_t                  *kioc;
      mbox64_t          *mbox64;
      uint8_t                 *raw_mbox;
      unsigned long           flags;

      kioc              = (uioc_t *)scb->gp;
      mbox64                  = (mbox64_t *)(unsigned long)kioc->cmdbuf;
      mbox64->mbox32.status   = scb->status;
      raw_mbox          = (uint8_t *)&mbox64->mbox32;


      // put scb in the free pool
      scb->state  = SCB_FREE;
      scb->scp    = NULL;

      spin_lock_irqsave(USER_FREE_LIST_LOCK(adapter), flags);

      list_add(&scb->list, &adapter->uscb_pool);

      spin_unlock_irqrestore(USER_FREE_LIST_LOCK(adapter), flags);

      // if a delete logical drive operation succeeded, restart the
      // controller
      if (raw_mbox[0] == FC_DEL_LOGDRV && raw_mbox[2] == OP_DEL_LOGDRV) {

            adapter->quiescent--;

            megaraid_mbox_runpendq(adapter, NULL);
      }

      kioc->done(kioc);

      return;
}


/**
 * gather_hbainfo - HBA characteristics for the applications
 * @adapter       : HBA soft state
 * @hinfo         : pointer to the caller's host info strucuture
 */
static int
gather_hbainfo(adapter_t *adapter, mraid_hba_info_t *hinfo)
{
      uint8_t     dmajor;

      dmajor                  = megaraid_mbox_version[0];

      hinfo->pci_vendor_id    = adapter->pdev->vendor;
      hinfo->pci_device_id    = adapter->pdev->device;
      hinfo->subsys_vendor_id = adapter->pdev->subsystem_vendor;
      hinfo->subsys_device_id = adapter->pdev->subsystem_device;

      hinfo->pci_bus          = adapter->pdev->bus->number;
      hinfo->pci_dev_fn = adapter->pdev->devfn;
      hinfo->pci_slot         = PCI_SLOT(adapter->pdev->devfn);
      hinfo->irq        = adapter->host->irq;
      hinfo->baseport         = ADAP2RAIDDEV(adapter)->baseport;

      hinfo->unique_id  = (hinfo->pci_bus << 8) | adapter->pdev->devfn;
      hinfo->host_no          = adapter->host->host_no;

      return 0;
}

/*
 * END: Interface for the common management module
 */



/**
 * megaraid_sysfs_alloc_resources - allocate sysfs related resources
 * @adapter : controller's soft state
 *
 * Allocate packets required to issue FW calls whenever the sysfs attributes
 * are read. These attributes would require up-to-date information from the
 * FW. Also set up resources for mutual exclusion to share these resources and
 * the wait queue.
 *
 * Return 0 on success.
 * Return -ERROR_CODE on failure.
 */
static int
megaraid_sysfs_alloc_resources(adapter_t *adapter)
{
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);
      int         rval = 0;

      raid_dev->sysfs_uioc = kmalloc(sizeof(uioc_t), GFP_KERNEL);

      raid_dev->sysfs_mbox64 = kmalloc(sizeof(mbox64_t), GFP_KERNEL);

      raid_dev->sysfs_buffer = pci_alloc_consistent(adapter->pdev,
                  PAGE_SIZE, &raid_dev->sysfs_buffer_dma);

      if (!raid_dev->sysfs_uioc || !raid_dev->sysfs_mbox64 ||
            !raid_dev->sysfs_buffer) {

            con_log(CL_ANN, (KERN_WARNING
                  "megaraid: out of memory, %s %d\n", __func__,
                  __LINE__));

            rval = -ENOMEM;

            megaraid_sysfs_free_resources(adapter);
      }

      mutex_init(&raid_dev->sysfs_mtx);

      init_waitqueue_head(&raid_dev->sysfs_wait_q);

      return rval;
}


/**
 * megaraid_sysfs_free_resources - free sysfs related resources
 * @adapter : controller's soft state
 *
 * Free packets allocated for sysfs FW commands
 */
static void
megaraid_sysfs_free_resources(adapter_t *adapter)
{
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);

      kfree(raid_dev->sysfs_uioc);
      kfree(raid_dev->sysfs_mbox64);

      if (raid_dev->sysfs_buffer) {
            pci_free_consistent(adapter->pdev, PAGE_SIZE,
                  raid_dev->sysfs_buffer, raid_dev->sysfs_buffer_dma);
      }
}


/**
 * megaraid_sysfs_get_ldmap_done - callback for get ldmap
 * @uioc    : completed packet
 *
 * Callback routine called in the ISR/tasklet context for get ldmap call
 */
static void
megaraid_sysfs_get_ldmap_done(uioc_t *uioc)
{
      adapter_t   *adapter = (adapter_t *)uioc->buf_vaddr;
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);

      uioc->status = 0;

      wake_up(&raid_dev->sysfs_wait_q);
}


/**
 * megaraid_sysfs_get_ldmap_timeout - timeout handling for get ldmap
 * @data    : timed out packet
 *
 * Timeout routine to recover and return to application, in case the adapter
 * has stopped responding. A timeout of 60 seconds for this command seems like
 * a good value.
 */
static void
megaraid_sysfs_get_ldmap_timeout(unsigned long data)
{
      uioc_t            *uioc = (uioc_t *)data;
      adapter_t   *adapter = (adapter_t *)uioc->buf_vaddr;
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);

      uioc->status = -ETIME;

      wake_up(&raid_dev->sysfs_wait_q);
}


/**
 * megaraid_sysfs_get_ldmap - get update logical drive map
 * @adapter : controller's soft state
 *
 * This routine will be called whenever user reads the logical drive
 * attributes, go get the current logical drive mapping table from the
 * firmware. We use the management API's to issue commands to the controller.
 *
 * NOTE: The commands issuance functionality is not generalized and
 * implemented in context of "get ld map" command only. If required, the
 * command issuance logical can be trivially pulled out and implemented as a
 * standalone libary. For now, this should suffice since there is no other
 * user of this interface.
 *
 * Return 0 on success.
 * Return -1 on failure.
 */
static int
megaraid_sysfs_get_ldmap(adapter_t *adapter)
{
      mraid_device_t          *raid_dev = ADAP2RAIDDEV(adapter);
      uioc_t                  *uioc;
      mbox64_t          *mbox64;
      mbox_t                  *mbox;
      char              *raw_mbox;
      struct timer_list sysfs_timer;
      struct timer_list *timerp;
      caddr_t                 ldmap;
      int               rval = 0;

      /*
       * Allow only one read at a time to go through the sysfs attributes
       */
      mutex_lock(&raid_dev->sysfs_mtx);

      uioc  = raid_dev->sysfs_uioc;
      mbox64      = raid_dev->sysfs_mbox64;
      ldmap = raid_dev->sysfs_buffer;

      memset(uioc, 0, sizeof(uioc_t));
      memset(mbox64, 0, sizeof(mbox64_t));
      memset(ldmap, 0, sizeof(raid_dev->curr_ldmap));

      mbox        = &mbox64->mbox32;
      raw_mbox    = (char *)mbox;
      uioc->cmdbuf    = (uint64_t)(unsigned long)mbox64;
      uioc->buf_vaddr   = (caddr_t)adapter;
      uioc->status      = -ENODATA;
      uioc->done  = megaraid_sysfs_get_ldmap_done;

      /*
       * Prepare the mailbox packet to get the current logical drive mapping
       * table
       */
      mbox->xferaddr = (uint32_t)raid_dev->sysfs_buffer_dma;

      raw_mbox[0] = FC_DEL_LOGDRV;
      raw_mbox[2] = OP_GET_LDID_MAP;

      /*
       * Setup a timer to recover from a non-responding controller
       */
      timerp      = &sysfs_timer;
      init_timer(timerp);

      timerp->function  = megaraid_sysfs_get_ldmap_timeout;
      timerp->data            = (unsigned long)uioc;
      timerp->expires         = jiffies + 60 * HZ;

      add_timer(timerp);

      /*
       * Send the command to the firmware
       */
      rval = megaraid_mbox_mm_command(adapter, uioc);

      if (rval == 0) {  // command successfully issued
            wait_event(raid_dev->sysfs_wait_q, (uioc->status != -ENODATA));

            /*
             * Check if the command timed out
             */
            if (uioc->status == -ETIME) {
                  con_log(CL_ANN, (KERN_NOTICE
                        "megaraid: sysfs get ld map timed out\n"));

                  rval = -ETIME;
            }
            else {
                  rval = mbox->status;
            }

            if (rval == 0) {
                  memcpy(raid_dev->curr_ldmap, ldmap,
                        sizeof(raid_dev->curr_ldmap));
            }
            else {
                  con_log(CL_ANN, (KERN_NOTICE
                        "megaraid: get ld map failed with %x\n", rval));
            }
      }
      else {
            con_log(CL_ANN, (KERN_NOTICE
                  "megaraid: could not issue ldmap command:%x\n", rval));
      }


      del_timer_sync(timerp);

      mutex_unlock(&raid_dev->sysfs_mtx);

      return rval;
}


/**
 * megaraid_sysfs_show_app_hndl - display application handle for this adapter
 * @cdev    : class device object representation for the host
 * @buf           : buffer to send data to
 *
 * Display the handle used by the applications while executing management
 * tasks on the adapter. We invoke a management module API to get the adapter
 * handle, since we do not interface with applications directly.
 */
static ssize_t
megaraid_sysfs_show_app_hndl(struct device *dev, struct device_attribute *attr,
                       char *buf)
{
      struct Scsi_Host *shost = class_to_shost(dev);
      adapter_t   *adapter = (adapter_t *)SCSIHOST2ADAP(shost);
      uint32_t    app_hndl;

      app_hndl = mraid_mm_adapter_app_handle(adapter->unique_id);

      return snprintf(buf, 8, "%u\n", app_hndl);
}


/**
 * megaraid_sysfs_show_ldnum - display the logical drive number for this device
 * @dev           : device object representation for the scsi device
 * @attr    : device attribute to show
 * @buf           : buffer to send data to
 *
 * Display the logical drive number for the device in question, if it a valid
 * logical drive. For physical devices, "-1" is returned.
 *
 * The logical drive number is displayed in following format:
 *
 * <SCSI ID> <LD NUM> <LD STICKY ID> <APP ADAPTER HANDLE>
 *
 *   <int>     <int>       <int>            <int>
 */
static ssize_t
megaraid_sysfs_show_ldnum(struct device *dev, struct device_attribute *attr, char *buf)
{
      struct scsi_device *sdev = to_scsi_device(dev);
      adapter_t   *adapter = (adapter_t *)SCSIHOST2ADAP(sdev->host);
      mraid_device_t    *raid_dev = ADAP2RAIDDEV(adapter);
      int         scsi_id = -1;
      int         logical_drv = -1;
      int         ldid_map = -1;
      uint32_t    app_hndl = 0;
      int         mapped_sdev_id;
      int         rval;
      int         i;

      if (raid_dev->random_del_supported &&
                  MRAID_IS_LOGICAL_SDEV(adapter, sdev)) {

            rval = megaraid_sysfs_get_ldmap(adapter);
            if (rval == 0) {

                  for (i = 0; i < MAX_LOGICAL_DRIVES_40LD; i++) {

                        mapped_sdev_id = sdev->id;

                        if (sdev->id > adapter->init_id) {
                              mapped_sdev_id -= 1;
                        }

                        if (raid_dev->curr_ldmap[i] == mapped_sdev_id) {

                              scsi_id = sdev->id;

                              logical_drv = i;

                              ldid_map = raid_dev->curr_ldmap[i];

                              app_hndl = mraid_mm_adapter_app_handle(
                                          adapter->unique_id);

                              break;
                        }
                  }
            }
            else {
                  con_log(CL_ANN, (KERN_NOTICE
                        "megaraid: sysfs get ld map failed: %x\n",
                        rval));
            }
      }

      return snprintf(buf, 36, "%d %d %d %d\n", scsi_id, logical_drv,
                  ldid_map, app_hndl);
}


/*
 * END: Mailbox Low Level Driver
 */
module_init(megaraid_init);
module_exit(megaraid_exit);

/* vim: set ts=8 sw=8 tw=78 ai si: */

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