/*
 *
 *                      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/scsi/ChangeLog.megaraid
 */

#include <linux/slab.h>
#include <linux/module.h>
#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_Host *, 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
 * @reason:     calling context
 *
 * Return value:
 *      actual depth set
 */
static int megaraid_change_queue_depth(struct scsi_device *sdev, int qdepth,
                                       int reason)
{
        if (reason != SCSI_QDEPTH_DEFAULT)
                return -EOPNOTSUPP;

        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_lck(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;
}

static DEF_SCSI_QCMD(megaraid_queue_command)

/**
 * 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 [%x] completed\n",
                                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 cmd=%x <c=%d t=%d l=%d>\n",
                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: %d[%d:%d], abort from completed list\n",
                                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: [%d:%d], driver owner\n",
                                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: %d[%d:%d], invalid state\n",
                                scb->sno, scb->dev_channel, scb->dev_target));
                                BUG();
                        }
                        else {
                                con_log(CL_ANN, (KERN_WARNING
                                "megaraid abort: %d[%d:%d], fw owner\n",
                                scb->sno, scb->dev_channel, scb->dev_target));
                        }
                }
        }
        spin_unlock_irq(&adapter->lock);

        if (!found) {
                con_log(CL_ANN, (KERN_WARNING "megaraid abort: do now own\n"));

                // 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: %d[%d:%d], reset from pending list\n",
                                        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 happened 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 successfully\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 appropriate 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 library. 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));