/*
 * pmcraid.c -- driver for PMC Sierra MaxRAID controller adapters
 *
 * Written By: Anil Ravindranath<anil_ravindranath@pmc-sierra.com>
 *             PMC-Sierra Inc
 *
 * Copyright (C) 2008, 2009 PMC Sierra Inc
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307,
 * USA
 *
 */
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/blkdev.h>
#include <linux/firmware.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/hdreg.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <asm/irq.h>
#include <asm/processor.h>
#include <linux/libata.h>
#include <linux/mutex.h>
#include <linux/ktime.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsicam.h>

#include "pmcraid.h"

/*
 *   Module configuration parameters
 */
static unsigned int pmcraid_debug_log;
static unsigned int pmcraid_disable_aen;
static unsigned int pmcraid_log_level = IOASC_LOG_LEVEL_MUST;
static unsigned int pmcraid_enable_msix;

/*
 * Data structures to support multiple adapters by the LLD.
 * pmcraid_adapter_count - count of configured adapters
 */
static atomic_t pmcraid_adapter_count = ATOMIC_INIT(0);

/*
 * Supporting user-level control interface through IOCTL commands.
 * pmcraid_major - major number to use
 * pmcraid_minor - minor number(s) to use
 */
static unsigned int pmcraid_major;
static struct class *pmcraid_class;
static DECLARE_BITMAP(pmcraid_minor, PMCRAID_MAX_ADAPTERS);

/*
 * Module parameters
 */
MODULE_AUTHOR("Anil Ravindranath<anil_ravindranath@pmc-sierra.com>");
MODULE_DESCRIPTION("PMC Sierra MaxRAID Controller Driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(PMCRAID_DRIVER_VERSION);

module_param_named(log_level, pmcraid_log_level, uint, (S_IRUGO | S_IWUSR));
MODULE_PARM_DESC(log_level,
                 "Enables firmware error code logging, default :1 high-severity"
                 " errors, 2: all errors including high-severity errors,"
                 " 0: disables logging");

module_param_named(debug, pmcraid_debug_log, uint, (S_IRUGO | S_IWUSR));
MODULE_PARM_DESC(debug,
                 "Enable driver verbose message logging. Set 1 to enable."
                 "(default: 0)");

module_param_named(disable_aen, pmcraid_disable_aen, uint, (S_IRUGO | S_IWUSR));
MODULE_PARM_DESC(disable_aen,
                 "Disable driver aen notifications to apps. Set 1 to disable."
                 "(default: 0)");

/* chip specific constants for PMC MaxRAID controllers (same for
 * 0x5220 and 0x8010
 */
static struct pmcraid_chip_details pmcraid_chip_cfg[] = {
        {
         .ioastatus = 0x0,
         .ioarrin = 0x00040,
         .mailbox = 0x7FC30,
         .global_intr_mask = 0x00034,
         .ioa_host_intr = 0x0009C,
         .ioa_host_intr_clr = 0x000A0,
         .ioa_host_msix_intr = 0x7FC40,
         .ioa_host_mask = 0x7FC28,
         .ioa_host_mask_clr = 0x7FC28,
         .host_ioa_intr = 0x00020,
         .host_ioa_intr_clr = 0x00020,
         .transop_timeout = 300
         }
};

/*
 * PCI device ids supported by pmcraid driver
 */
static struct pci_device_id pmcraid_pci_table[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_PMC, PCI_DEVICE_ID_PMC_MAXRAID),
          0, 0, (kernel_ulong_t)&pmcraid_chip_cfg[0]
        },
        {}
};

MODULE_DEVICE_TABLE(pci, pmcraid_pci_table);



/**
 * pmcraid_slave_alloc - Prepare for commands to a device
 * @scsi_dev: scsi device struct
 *
 * This function is called by mid-layer prior to sending any command to the new
 * device. Stores resource entry details of the device in scsi_device struct.
 * Queuecommand uses the resource handle and other details to fill up IOARCB
 * while sending commands to the device.
 *
 * Return value:
 *        0 on success / -ENXIO if device does not exist
 */
static int pmcraid_slave_alloc(struct scsi_device *scsi_dev)
{
        struct pmcraid_resource_entry *temp, *res = NULL;
        struct pmcraid_instance *pinstance;
        u8 target, bus, lun;
        unsigned long lock_flags;
        int rc = -ENXIO;
        u16 fw_version;

        pinstance = shost_priv(scsi_dev->host);

        fw_version = be16_to_cpu(pinstance->inq_data->fw_version);

        /* Driver exposes VSET and GSCSI resources only; all other device types
         * are not exposed. Resource list is synchronized using resource lock
         * so any traversal or modifications to the list should be done inside
         * this lock
         */
        spin_lock_irqsave(&pinstance->resource_lock, lock_flags);
        list_for_each_entry(temp, &pinstance->used_res_q, queue) {

                /* do not expose VSETs with order-ids > MAX_VSET_TARGETS */
                if (RES_IS_VSET(temp->cfg_entry)) {
                        if (fw_version <= PMCRAID_FW_VERSION_1)
                                target = temp->cfg_entry.unique_flags1;
                        else
                                target = le16_to_cpu(temp->cfg_entry.array_id) & 0xFF;

                        if (target > PMCRAID_MAX_VSET_TARGETS)
                                continue;
                        bus = PMCRAID_VSET_BUS_ID;
                        lun = 0;
                } else if (RES_IS_GSCSI(temp->cfg_entry)) {
                        target = RES_TARGET(temp->cfg_entry.resource_address);
                        bus = PMCRAID_PHYS_BUS_ID;
                        lun = RES_LUN(temp->cfg_entry.resource_address);
                } else {
                        continue;
                }

                if (bus == scsi_dev->channel &&
                    target == scsi_dev->id &&
                    lun == scsi_dev->lun) {
                        res = temp;
                        break;
                }
        }

        if (res) {
                res->scsi_dev = scsi_dev;
                scsi_dev->hostdata = res;
                res->change_detected = 0;
                atomic_set(&res->read_failures, 0);
                atomic_set(&res->write_failures, 0);
                rc = 0;
        }
        spin_unlock_irqrestore(&pinstance->resource_lock, lock_flags);
        return rc;
}

/**
 * pmcraid_slave_configure - Configures a SCSI device
 * @scsi_dev: scsi device struct
 *
 * This function is executed by SCSI mid layer just after a device is first
 * scanned (i.e. it has responded to an INQUIRY). For VSET resources, the
 * timeout value (default 30s) will be over-written to a higher value (60s)
 * and max_sectors value will be over-written to 512. It also sets queue depth
 * to host->cmd_per_lun value
 *
 * Return value:
 *        0 on success
 */
static int pmcraid_slave_configure(struct scsi_device *scsi_dev)
{
        struct pmcraid_resource_entry *res = scsi_dev->hostdata;

        if (!res)
                return 0;

        /* LLD exposes VSETs and Enclosure devices only */
        if (RES_IS_GSCSI(res->cfg_entry) &&
            scsi_dev->type != TYPE_ENCLOSURE)
                return -ENXIO;

        pmcraid_info("configuring %x:%x:%x:%x\n",
                     scsi_dev->host->unique_id,
                     scsi_dev->channel,
                     scsi_dev->id,
                     (u8)scsi_dev->lun);

        if (RES_IS_GSCSI(res->cfg_entry)) {
                scsi_dev->allow_restart = 1;
        } else if (RES_IS_VSET(res->cfg_entry)) {
                scsi_dev->allow_restart = 1;
                blk_queue_rq_timeout(scsi_dev->request_queue,
                                     PMCRAID_VSET_IO_TIMEOUT);
                blk_queue_max_hw_sectors(scsi_dev->request_queue,
                                      PMCRAID_VSET_MAX_SECTORS);
        }

        /*
         * We never want to report TCQ support for these types of devices.
         */
        if (!RES_IS_GSCSI(res->cfg_entry) && !RES_IS_VSET(res->cfg_entry))
                scsi_dev->tagged_supported = 0;

        return 0;
}

/**
 * pmcraid_slave_destroy - Unconfigure a SCSI device before removing it
 *
 * @scsi_dev: scsi device struct
 *
 * This is called by mid-layer before removing a device. Pointer assignments
 * done in pmcraid_slave_alloc will be reset to NULL here.
 *
 * Return value
 *   none
 */
static void pmcraid_slave_destroy(struct scsi_device *scsi_dev)
{
        struct pmcraid_resource_entry *res;

        res = (struct pmcraid_resource_entry *)scsi_dev->hostdata;

        if (res)
                res->scsi_dev = NULL;

        scsi_dev->hostdata = NULL;
}

/**
 * pmcraid_change_queue_depth - Change the device's queue depth
 * @scsi_dev: scsi device struct
 * @depth: depth to set
 *
 * Return value
 *      actual depth set
 */
static int pmcraid_change_queue_depth(struct scsi_device *scsi_dev, int depth)
{
        if (depth > PMCRAID_MAX_CMD_PER_LUN)
                depth = PMCRAID_MAX_CMD_PER_LUN;
        return scsi_change_queue_depth(scsi_dev, depth);
}

/**
 * pmcraid_init_cmdblk - initializes a command block
 *
 * @cmd: pointer to struct pmcraid_cmd to be initialized
 * @index: if >=0 first time initialization; otherwise reinitialization
 *
 * Return Value
 *       None
 */
static void pmcraid_init_cmdblk(struct pmcraid_cmd *cmd, int index)
{
        struct pmcraid_ioarcb *ioarcb = &(cmd->ioa_cb->ioarcb);
        dma_addr_t dma_addr = cmd->ioa_cb_bus_addr;

        if (index >= 0) {
                /* first time initialization (called from  probe) */
                u32 ioasa_offset =
                        offsetof(struct pmcraid_control_block, ioasa);

                cmd->index = index;
                ioarcb->response_handle = cpu_to_le32(index << 2);
                ioarcb->ioarcb_bus_addr = cpu_to_le64(dma_addr);
                ioarcb->ioasa_bus_addr = cpu_to_le64(dma_addr + ioasa_offset);
                ioarcb->ioasa_len = cpu_to_le16(sizeof(struct pmcraid_ioasa));
        } else {
                /* re-initialization of various lengths, called once command is
                 * processed by IOA
                 */
                memset(&cmd->ioa_cb->ioarcb.cdb, 0, PMCRAID_MAX_CDB_LEN);
                ioarcb->hrrq_id = 0;
                ioarcb->request_flags0 = 0;
                ioarcb->request_flags1 = 0;
                ioarcb->cmd_timeout = 0;
                ioarcb->ioarcb_bus_addr &= cpu_to_le64(~0x1FULL);
                ioarcb->ioadl_bus_addr = 0;
                ioarcb->ioadl_length = 0;
                ioarcb->data_transfer_length = 0;
                ioarcb->add_cmd_param_length = 0;
                ioarcb->add_cmd_param_offset = 0;
                cmd->ioa_cb->ioasa.ioasc = 0;
                cmd->ioa_cb->ioasa.residual_data_length = 0;
                cmd->time_left = 0;
        }

        cmd->cmd_done = NULL;
        cmd->scsi_cmd = NULL;
        cmd->release = 0;
        cmd->completion_req = 0;
        cmd->sense_buffer = NULL;
        cmd->sense_buffer_dma = 0;
        cmd->dma_handle = 0;
        init_timer(&cmd->timer);
}

/**
 * pmcraid_reinit_cmdblk - reinitialize a command block
 *
 * @cmd: pointer to struct pmcraid_cmd to be reinitialized
 *
 * Return Value
 *       None
 */
static void pmcraid_reinit_cmdblk(struct pmcraid_cmd *cmd)
{
        pmcraid_init_cmdblk(cmd, -1);
}

/**
 * pmcraid_get_free_cmd - get a free cmd block from command block pool
 * @pinstance: adapter instance structure
 *
 * Return Value:
 *      returns pointer to cmd block or NULL if no blocks are available
 */
static struct pmcraid_cmd *pmcraid_get_free_cmd(
        struct pmcraid_instance *pinstance
)
{
        struct pmcraid_cmd *cmd = NULL;
        unsigned long lock_flags;

        /* free cmd block list is protected by free_pool_lock */
        spin_lock_irqsave(&pinstance->free_pool_lock, lock_flags);

        if (!list_empty(&pinstance->free_cmd_pool)) {
                cmd = list_entry(pinstance->free_cmd_pool.next,
                                 struct pmcraid_cmd, free_list);
                list_del(&cmd->free_list);
        }
        spin_unlock_irqrestore(&pinstance->free_pool_lock, lock_flags);

        /* Initialize the command block before giving it the caller */
        if (cmd != NULL)
                pmcraid_reinit_cmdblk(cmd);
        return cmd;
}

/**
 * pmcraid_return_cmd - return a completed command block back into free pool
 * @cmd: pointer to the command block
 *
 * Return Value:
 *      nothing
 */
static void pmcraid_return_cmd(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        unsigned long lock_flags;

        spin_lock_irqsave(&pinstance->free_pool_lock, lock_flags);
        list_add_tail(&cmd->free_list, &pinstance->free_cmd_pool);
        spin_unlock_irqrestore(&pinstance->free_pool_lock, lock_flags);
}

/**
 * pmcraid_read_interrupts -  reads IOA interrupts
 *
 * @pinstance: pointer to adapter instance structure
 *
 * Return value
 *       interrupts read from IOA
 */
static u32 pmcraid_read_interrupts(struct pmcraid_instance *pinstance)
{
        return (pinstance->interrupt_mode) ?
                ioread32(pinstance->int_regs.ioa_host_msix_interrupt_reg) :
                ioread32(pinstance->int_regs.ioa_host_interrupt_reg);
}

/**
 * pmcraid_disable_interrupts - Masks and clears all specified interrupts
 *
 * @pinstance: pointer to per adapter instance structure
 * @intrs: interrupts to disable
 *
 * Return Value
 *       None
 */
static void pmcraid_disable_interrupts(
        struct pmcraid_instance *pinstance,
        u32 intrs
)
{
        u32 gmask = ioread32(pinstance->int_regs.global_interrupt_mask_reg);
        u32 nmask = gmask | GLOBAL_INTERRUPT_MASK;

        iowrite32(intrs, pinstance->int_regs.ioa_host_interrupt_clr_reg);
        iowrite32(nmask, pinstance->int_regs.global_interrupt_mask_reg);
        ioread32(pinstance->int_regs.global_interrupt_mask_reg);

        if (!pinstance->interrupt_mode) {
                iowrite32(intrs,
                        pinstance->int_regs.ioa_host_interrupt_mask_reg);
                ioread32(pinstance->int_regs.ioa_host_interrupt_mask_reg);
        }
}

/**
 * pmcraid_enable_interrupts - Enables specified interrupts
 *
 * @pinstance: pointer to per adapter instance structure
 * @intr: interrupts to enable
 *
 * Return Value
 *       None
 */
static void pmcraid_enable_interrupts(
        struct pmcraid_instance *pinstance,
        u32 intrs
)
{
        u32 gmask = ioread32(pinstance->int_regs.global_interrupt_mask_reg);
        u32 nmask = gmask & (~GLOBAL_INTERRUPT_MASK);

        iowrite32(nmask, pinstance->int_regs.global_interrupt_mask_reg);

        if (!pinstance->interrupt_mode) {
                iowrite32(~intrs,
                         pinstance->int_regs.ioa_host_interrupt_mask_reg);
                ioread32(pinstance->int_regs.ioa_host_interrupt_mask_reg);
        }

        pmcraid_info("enabled interrupts global mask = %x intr_mask = %x\n",
                ioread32(pinstance->int_regs.global_interrupt_mask_reg),
                ioread32(pinstance->int_regs.ioa_host_interrupt_mask_reg));
}

/**
 * pmcraid_clr_trans_op - clear trans to op interrupt
 *
 * @pinstance: pointer to per adapter instance structure
 *
 * Return Value
 *       None
 */
static void pmcraid_clr_trans_op(
        struct pmcraid_instance *pinstance
)
{
        unsigned long lock_flags;

        if (!pinstance->interrupt_mode) {
                iowrite32(INTRS_TRANSITION_TO_OPERATIONAL,
                        pinstance->int_regs.ioa_host_interrupt_mask_reg);
                ioread32(pinstance->int_regs.ioa_host_interrupt_mask_reg);
                iowrite32(INTRS_TRANSITION_TO_OPERATIONAL,
                        pinstance->int_regs.ioa_host_interrupt_clr_reg);
                ioread32(pinstance->int_regs.ioa_host_interrupt_clr_reg);
        }

        if (pinstance->reset_cmd != NULL) {
                del_timer(&pinstance->reset_cmd->timer);
                spin_lock_irqsave(
                        pinstance->host->host_lock, lock_flags);
                pinstance->reset_cmd->cmd_done(pinstance->reset_cmd);
                spin_unlock_irqrestore(
                        pinstance->host->host_lock, lock_flags);
        }
}

/**
 * pmcraid_reset_type - Determine the required reset type
 * @pinstance: pointer to adapter instance structure
 *
 * IOA requires hard reset if any of the following conditions is true.
 * 1. If HRRQ valid interrupt is not masked
 * 2. IOA reset alert doorbell is set
 * 3. If there are any error interrupts
 */
static void pmcraid_reset_type(struct pmcraid_instance *pinstance)
{
        u32 mask;
        u32 intrs;
        u32 alerts;

        mask = ioread32(pinstance->int_regs.ioa_host_interrupt_mask_reg);
        intrs = ioread32(pinstance->int_regs.ioa_host_interrupt_reg);
        alerts = ioread32(pinstance->int_regs.host_ioa_interrupt_reg);

        if ((mask & INTRS_HRRQ_VALID) == 0 ||
            (alerts & DOORBELL_IOA_RESET_ALERT) ||
            (intrs & PMCRAID_ERROR_INTERRUPTS)) {
                pmcraid_info("IOA requires hard reset\n");
                pinstance->ioa_hard_reset = 1;
        }

        /* If unit check is active, trigger the dump */
        if (intrs & INTRS_IOA_UNIT_CHECK)
                pinstance->ioa_unit_check = 1;
}

/**
 * pmcraid_bist_done - completion function for PCI BIST
 * @cmd: pointer to reset command
 * Return Value
 *      none
 */

static void pmcraid_ioa_reset(struct pmcraid_cmd *);

static void pmcraid_bist_done(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        unsigned long lock_flags;
        int rc;
        u16 pci_reg;

        rc = pci_read_config_word(pinstance->pdev, PCI_COMMAND, &pci_reg);

        /* If PCI config space can't be accessed wait for another two secs */
        if ((rc != PCIBIOS_SUCCESSFUL || (!(pci_reg & PCI_COMMAND_MEMORY))) &&
            cmd->time_left > 0) {
                pmcraid_info("BIST not complete, waiting another 2 secs\n");
                cmd->timer.expires = jiffies + cmd->time_left;
                cmd->time_left = 0;
                cmd->timer.data = (unsigned long)cmd;
                cmd->timer.function =
                        (void (*)(unsigned long))pmcraid_bist_done;
                add_timer(&cmd->timer);
        } else {
                cmd->time_left = 0;
                pmcraid_info("BIST is complete, proceeding with reset\n");
                spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
                pmcraid_ioa_reset(cmd);
                spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
        }
}

/**
 * pmcraid_start_bist - starts BIST
 * @cmd: pointer to reset cmd
 * Return Value
 *   none
 */
static void pmcraid_start_bist(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u32 doorbells, intrs;

        /* proceed with bist and wait for 2 seconds */
        iowrite32(DOORBELL_IOA_START_BIST,
                pinstance->int_regs.host_ioa_interrupt_reg);
        doorbells = ioread32(pinstance->int_regs.host_ioa_interrupt_reg);
        intrs = ioread32(pinstance->int_regs.ioa_host_interrupt_reg);
        pmcraid_info("doorbells after start bist: %x intrs: %x\n",
                      doorbells, intrs);

        cmd->time_left = msecs_to_jiffies(PMCRAID_BIST_TIMEOUT);
        cmd->timer.data = (unsigned long)cmd;
        cmd->timer.expires = jiffies + msecs_to_jiffies(PMCRAID_BIST_TIMEOUT);
        cmd->timer.function = (void (*)(unsigned long))pmcraid_bist_done;
        add_timer(&cmd->timer);
}

/**
 * pmcraid_reset_alert_done - completion routine for reset_alert
 * @cmd: pointer to command block used in reset sequence
 * Return value
 *  None
 */
static void pmcraid_reset_alert_done(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u32 status = ioread32(pinstance->ioa_status);
        unsigned long lock_flags;

        /* if the critical operation in progress bit is set or the wait times
         * out, invoke reset engine to proceed with hard reset. If there is
         * some more time to wait, restart the timer
         */
        if (((status & INTRS_CRITICAL_OP_IN_PROGRESS) == 0) ||
            cmd->time_left <= 0) {
                pmcraid_info("critical op is reset proceeding with reset\n");
                spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
                pmcraid_ioa_reset(cmd);
                spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
        } else {
                pmcraid_info("critical op is not yet reset waiting again\n");
                /* restart timer if some more time is available to wait */
                cmd->time_left -= PMCRAID_CHECK_FOR_RESET_TIMEOUT;
                cmd->timer.data = (unsigned long)cmd;
                cmd->timer.expires = jiffies + PMCRAID_CHECK_FOR_RESET_TIMEOUT;
                cmd->timer.function =
                        (void (*)(unsigned long))pmcraid_reset_alert_done;
                add_timer(&cmd->timer);
        }
}

/**
 * pmcraid_reset_alert - alerts IOA for a possible reset
 * @cmd : command block to be used for reset sequence.
 *
 * Return Value
 *      returns 0 if pci config-space is accessible and RESET_DOORBELL is
 *      successfully written to IOA. Returns non-zero in case pci_config_space
 *      is not accessible
 */
static void pmcraid_notify_ioastate(struct pmcraid_instance *, u32);
static void pmcraid_reset_alert(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u32 doorbells;
        int rc;
        u16 pci_reg;

        /* If we are able to access IOA PCI config space, alert IOA that we are
         * going to reset it soon. This enables IOA to preserv persistent error
         * data if any. In case memory space is not accessible, proceed with
         * BIST or slot_reset
         */
        rc = pci_read_config_word(pinstance->pdev, PCI_COMMAND, &pci_reg);
        if ((rc == PCIBIOS_SUCCESSFUL) && (pci_reg & PCI_COMMAND_MEMORY)) {

                /* wait for IOA permission i.e until CRITICAL_OPERATION bit is
                 * reset IOA doesn't generate any interrupts when CRITICAL
                 * OPERATION bit is reset. A timer is started to wait for this
                 * bit to be reset.
                 */
                cmd->time_left = PMCRAID_RESET_TIMEOUT;
                cmd->timer.data = (unsigned long)cmd;
                cmd->timer.expires = jiffies + PMCRAID_CHECK_FOR_RESET_TIMEOUT;
                cmd->timer.function =
                        (void (*)(unsigned long))pmcraid_reset_alert_done;
                add_timer(&cmd->timer);

                iowrite32(DOORBELL_IOA_RESET_ALERT,
                        pinstance->int_regs.host_ioa_interrupt_reg);
                doorbells =
                        ioread32(pinstance->int_regs.host_ioa_interrupt_reg);
                pmcraid_info("doorbells after reset alert: %x\n", doorbells);
        } else {
                pmcraid_info("PCI config is not accessible starting BIST\n");
                pinstance->ioa_state = IOA_STATE_IN_HARD_RESET;
                pmcraid_start_bist(cmd);
        }
}

/**
 * pmcraid_timeout_handler -  Timeout handler for internally generated ops
 *
 * @cmd : pointer to command structure, that got timedout
 *
 * This function blocks host requests and initiates an adapter reset.
 *
 * Return value:
 *   None
 */
static void pmcraid_timeout_handler(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        unsigned long lock_flags;

        dev_info(&pinstance->pdev->dev,
                "Adapter being reset due to cmd(CDB[0] = %x) timeout\n",
                cmd->ioa_cb->ioarcb.cdb[0]);

        /* Command timeouts result in hard reset sequence. The command that got
         * timed out may be the one used as part of reset sequence. In this
         * case restart reset sequence using the same command block even if
         * reset is in progress. Otherwise fail this command and get a free
         * command block to restart the reset sequence.
         */
        spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
        if (!pinstance->ioa_reset_in_progress) {
                pinstance->ioa_reset_attempts = 0;
                cmd = pmcraid_get_free_cmd(pinstance);

                /* If we are out of command blocks, just return here itself.
                 * Some other command's timeout handler can do the reset job
                 */
                if (cmd == NULL) {
                        spin_unlock_irqrestore(pinstance->host->host_lock,
                                               lock_flags);
                        pmcraid_err("no free cmnd block for timeout handler\n");
                        return;
                }

                pinstance->reset_cmd = cmd;
                pinstance->ioa_reset_in_progress = 1;
        } else {
                pmcraid_info("reset is already in progress\n");

                if (pinstance->reset_cmd != cmd) {
                        /* This command should have been given to IOA, this
                         * command will be completed by fail_outstanding_cmds
                         * anyway
                         */
                        pmcraid_err("cmd is pending but reset in progress\n");
                }

                /* If this command was being used as part of the reset
                 * sequence, set cmd_done pointer to pmcraid_ioa_reset. This
                 * causes fail_outstanding_commands not to return the command
                 * block back to free pool
                 */
                if (cmd == pinstance->reset_cmd)
                        cmd->cmd_done = pmcraid_ioa_reset;
        }

        /* Notify apps of important IOA bringup/bringdown sequences */
        if (pinstance->scn.ioa_state != PMC_DEVICE_EVENT_RESET_START &&
            pinstance->scn.ioa_state != PMC_DEVICE_EVENT_SHUTDOWN_START)
                pmcraid_notify_ioastate(pinstance,
                                        PMC_DEVICE_EVENT_RESET_START);

        pinstance->ioa_state = IOA_STATE_IN_RESET_ALERT;
        scsi_block_requests(pinstance->host);
        pmcraid_reset_alert(cmd);
        spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
}

/**
 * pmcraid_internal_done - completion routine for internally generated cmds
 *
 * @cmd: command that got response from IOA
 *
 * Return Value:
 *       none
 */
static void pmcraid_internal_done(struct pmcraid_cmd *cmd)
{
        pmcraid_info("response internal cmd CDB[0] = %x ioasc = %x\n",
                     cmd->ioa_cb->ioarcb.cdb[0],
                     le32_to_cpu(cmd->ioa_cb->ioasa.ioasc));

        /* Some of the internal commands are sent with callers blocking for the
         * response. Same will be indicated as part of cmd->completion_req
         * field. Response path needs to wake up any waiters waiting for cmd
         * completion if this flag is set.
         */
        if (cmd->completion_req) {
                cmd->completion_req = 0;
                complete(&cmd->wait_for_completion);
        }

        /* most of the internal commands are completed by caller itself, so
         * no need to return the command block back to free pool until we are
         * required to do so (e.g once done with initialization).
         */
        if (cmd->release) {
                cmd->release = 0;
                pmcraid_return_cmd(cmd);
        }
}

/**
 * pmcraid_reinit_cfgtable_done - done function for cfg table reinitialization
 *
 * @cmd: command that got response from IOA
 *
 * This routine is called after driver re-reads configuration table due to a
 * lost CCN. It returns the command block back to free pool and schedules
 * worker thread to add/delete devices into the system.
 *
 * Return Value:
 *       none
 */
static void pmcraid_reinit_cfgtable_done(struct pmcraid_cmd *cmd)
{
        pmcraid_info("response internal cmd CDB[0] = %x ioasc = %x\n",
                     cmd->ioa_cb->ioarcb.cdb[0],
                     le32_to_cpu(cmd->ioa_cb->ioasa.ioasc));

        if (cmd->release) {
                cmd->release = 0;
                pmcraid_return_cmd(cmd);
        }
        pmcraid_info("scheduling worker for config table reinitialization\n");
        schedule_work(&cmd->drv_inst->worker_q);
}

/**
 * pmcraid_erp_done - Process completion of SCSI error response from device
 * @cmd: pmcraid_command
 *
 * This function copies the sense buffer into the scsi_cmd struct and completes
 * scsi_cmd by calling scsi_done function.
 *
 * Return value:
 *  none
 */
static void pmcraid_erp_done(struct pmcraid_cmd *cmd)
{
        struct scsi_cmnd *scsi_cmd = cmd->scsi_cmd;
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u32 ioasc = le32_to_cpu(cmd->ioa_cb->ioasa.ioasc);

        if (PMCRAID_IOASC_SENSE_KEY(ioasc) > 0) {
                scsi_cmd->result |= (DID_ERROR << 16);
                scmd_printk(KERN_INFO, scsi_cmd,
                            "command CDB[0] = %x failed with IOASC: 0x%08X\n",
                            cmd->ioa_cb->ioarcb.cdb[0], ioasc);
        }

        /* if we had allocated sense buffers for request sense, copy the sense
         * release the buffers
         */
        if (cmd->sense_buffer != NULL) {
                memcpy(scsi_cmd->sense_buffer,
                       cmd->sense_buffer,
                       SCSI_SENSE_BUFFERSIZE);
                pci_free_consistent(pinstance->pdev,
                                    SCSI_SENSE_BUFFERSIZE,
                                    cmd->sense_buffer, cmd->sense_buffer_dma);
                cmd->sense_buffer = NULL;
                cmd->sense_buffer_dma = 0;
        }

        scsi_dma_unmap(scsi_cmd);
        pmcraid_return_cmd(cmd);
        scsi_cmd->scsi_done(scsi_cmd);
}

/**
 * pmcraid_fire_command - sends an IOA command to adapter
 *
 * This function adds the given block into pending command list
 * and returns without waiting
 *
 * @cmd : command to be sent to the device
 *
 * Return Value
 *      None
 */
static void _pmcraid_fire_command(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        unsigned long lock_flags;

        /* Add this command block to pending cmd pool. We do this prior to
         * writting IOARCB to ioarrin because IOA might complete the command
         * by the time we are about to add it to the list. Response handler
         * (isr/tasklet) looks for cmd block in the pending pending list.
         */
        spin_lock_irqsave(&pinstance->pending_pool_lock, lock_flags);
        list_add_tail(&cmd->free_list, &pinstance->pending_cmd_pool);
        spin_unlock_irqrestore(&pinstance->pending_pool_lock, lock_flags);
        atomic_inc(&pinstance->outstanding_cmds);

        /* driver writes lower 32-bit value of IOARCB address only */
        mb();
        iowrite32(le64_to_cpu(cmd->ioa_cb->ioarcb.ioarcb_bus_addr), pinstance->ioarrin);
}

/**
 * pmcraid_send_cmd - fires a command to IOA
 *
 * This function also sets up timeout function, and command completion
 * function
 *
 * @cmd: pointer to the command block to be fired to IOA
 * @cmd_done: command completion function, called once IOA responds
 * @timeout: timeout to wait for this command completion
 * @timeout_func: timeout handler
 *
 * Return value
 *   none
 */
static void pmcraid_send_cmd(
        struct pmcraid_cmd *cmd,
        void (*cmd_done) (struct pmcraid_cmd *),
        unsigned long timeout,
        void (*timeout_func) (struct pmcraid_cmd *)
)
{
        /* initialize done function */
        cmd->cmd_done = cmd_done;

        if (timeout_func) {
                /* setup timeout handler */
                cmd->timer.data = (unsigned long)cmd;
                cmd->timer.expires = jiffies + timeout;
                cmd->timer.function = (void (*)(unsigned long))timeout_func;
                add_timer(&cmd->timer);
        }

        /* fire the command to IOA */
        _pmcraid_fire_command(cmd);
}

/**
 * pmcraid_ioa_shutdown_done - completion function for IOA shutdown command
 * @cmd: pointer to the command block used for sending IOA shutdown command
 *
 * Return value
 *  None
 */
static void pmcraid_ioa_shutdown_done(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        unsigned long lock_flags;

        spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
        pmcraid_ioa_reset(cmd);
        spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
}

/**
 * pmcraid_ioa_shutdown - sends SHUTDOWN command to ioa
 *
 * @cmd: pointer to the command block used as part of reset sequence
 *
 * Return Value
 *  None
 */
static void pmcraid_ioa_shutdown(struct pmcraid_cmd *cmd)
{
        pmcraid_info("response for Cancel CCN CDB[0] = %x ioasc = %x\n",
                     cmd->ioa_cb->ioarcb.cdb[0],
                     le32_to_cpu(cmd->ioa_cb->ioasa.ioasc));

        /* Note that commands sent during reset require next command to be sent
         * to IOA. Hence reinit the done function as well as timeout function
         */
        pmcraid_reinit_cmdblk(cmd);
        cmd->ioa_cb->ioarcb.request_type = REQ_TYPE_IOACMD;
        cmd->ioa_cb->ioarcb.resource_handle =
                cpu_to_le32(PMCRAID_IOA_RES_HANDLE);
        cmd->ioa_cb->ioarcb.cdb[0] = PMCRAID_IOA_SHUTDOWN;
        cmd->ioa_cb->ioarcb.cdb[1] = PMCRAID_SHUTDOWN_NORMAL;

        /* fire shutdown command to hardware. */
        pmcraid_info("firing normal shutdown command (%d) to IOA\n",
                     le32_to_cpu(cmd->ioa_cb->ioarcb.response_handle));

        pmcraid_notify_ioastate(cmd->drv_inst, PMC_DEVICE_EVENT_SHUTDOWN_START);

        pmcraid_send_cmd(cmd, pmcraid_ioa_shutdown_done,
                         PMCRAID_SHUTDOWN_TIMEOUT,
                         pmcraid_timeout_handler);
}

/**
 * pmcraid_get_fwversion_done - completion function for get_fwversion
 *
 * @cmd: pointer to command block used to send INQUIRY command
 *
 * Return Value
 *      none
 */
static void pmcraid_querycfg(struct pmcraid_cmd *);

static void pmcraid_get_fwversion_done(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u32 ioasc = le32_to_cpu(cmd->ioa_cb->ioasa.ioasc);
        unsigned long lock_flags;

        /* configuration table entry size depends on firmware version. If fw
         * version is not known, it is not possible to interpret IOA config
         * table
         */
        if (ioasc) {
                pmcraid_err("IOA Inquiry failed with %x\n", ioasc);
                spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
                pinstance->ioa_state = IOA_STATE_IN_RESET_ALERT;
                pmcraid_reset_alert(cmd);
                spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
        } else  {
                pmcraid_querycfg(cmd);
        }
}

/**
 * pmcraid_get_fwversion - reads firmware version information
 *
 * @cmd: pointer to command block used to send INQUIRY command
 *
 * Return Value
 *      none
 */
static void pmcraid_get_fwversion(struct pmcraid_cmd *cmd)
{
        struct pmcraid_ioarcb *ioarcb = &cmd->ioa_cb->ioarcb;
        struct pmcraid_ioadl_desc *ioadl = ioarcb->add_data.u.ioadl;
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u16 data_size = sizeof(struct pmcraid_inquiry_data);

        pmcraid_reinit_cmdblk(cmd);
        ioarcb->request_type = REQ_TYPE_SCSI;
        ioarcb->resource_handle = cpu_to_le32(PMCRAID_IOA_RES_HANDLE);
        ioarcb->cdb[0] = INQUIRY;
        ioarcb->cdb[1] = 1;
        ioarcb->cdb[2] = 0xD0;
        ioarcb->cdb[3] = (data_size >> 8) & 0xFF;
        ioarcb->cdb[4] = data_size & 0xFF;

        /* Since entire inquiry data it can be part of IOARCB itself
         */
        ioarcb->ioadl_bus_addr = cpu_to_le64((cmd->ioa_cb_bus_addr) +
                                        offsetof(struct pmcraid_ioarcb,
                                                add_data.u.ioadl[0]));
        ioarcb->ioadl_length = cpu_to_le32(sizeof(struct pmcraid_ioadl_desc));
        ioarcb->ioarcb_bus_addr &= cpu_to_le64(~(0x1FULL));

        ioarcb->request_flags0 |= NO_LINK_DESCS;
        ioarcb->data_transfer_length = cpu_to_le32(data_size);
        ioadl = &(ioarcb->add_data.u.ioadl[0]);
        ioadl->flags = IOADL_FLAGS_LAST_DESC;
        ioadl->address = cpu_to_le64(pinstance->inq_data_baddr);
        ioadl->data_len = cpu_to_le32(data_size);

        pmcraid_send_cmd(cmd, pmcraid_get_fwversion_done,
                         PMCRAID_INTERNAL_TIMEOUT, pmcraid_timeout_handler);
}

/**
 * pmcraid_identify_hrrq - registers host rrq buffers with IOA
 * @cmd: pointer to command block to be used for identify hrrq
 *
 * Return Value
 *       none
 */
static void pmcraid_identify_hrrq(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        struct pmcraid_ioarcb *ioarcb = &cmd->ioa_cb->ioarcb;
        int index = cmd->hrrq_index;
        __be64 hrrq_addr = cpu_to_be64(pinstance->hrrq_start_bus_addr[index]);
        __be32 hrrq_size = cpu_to_be32(sizeof(u32) * PMCRAID_MAX_CMD);
        void (*done_function)(struct pmcraid_cmd *);

        pmcraid_reinit_cmdblk(cmd);
        cmd->hrrq_index = index + 1;

        if (cmd->hrrq_index < pinstance->num_hrrq) {
                done_function = pmcraid_identify_hrrq;
        } else {
                cmd->hrrq_index = 0;
                done_function = pmcraid_get_fwversion;
        }

        /* Initialize ioarcb */
        ioarcb->request_type = REQ_TYPE_IOACMD;
        ioarcb->resource_handle = cpu_to_le32(PMCRAID_IOA_RES_HANDLE);

        /* initialize the hrrq number where IOA will respond to this command */
        ioarcb->hrrq_id = index;
        ioarcb->cdb[0] = PMCRAID_IDENTIFY_HRRQ;
        ioarcb->cdb[1] = index;

        /* IOA expects 64-bit pci address to be written in B.E format
         * (i.e cdb[2]=MSByte..cdb[9]=LSB.
         */
        pmcraid_info("HRRQ_IDENTIFY with hrrq:ioarcb:index => %llx:%llx:%x\n",
                     hrrq_addr, ioarcb->ioarcb_bus_addr, index);

        memcpy(&(ioarcb->cdb[2]), &hrrq_addr, sizeof(hrrq_addr));
        memcpy(&(ioarcb->cdb[10]), &hrrq_size, sizeof(hrrq_size));

        /* Subsequent commands require HRRQ identification to be successful.
         * Note that this gets called even during reset from SCSI mid-layer
         * or tasklet
         */
        pmcraid_send_cmd(cmd, done_function,
                         PMCRAID_INTERNAL_TIMEOUT,
                         pmcraid_timeout_handler);
}

static void pmcraid_process_ccn(struct pmcraid_cmd *cmd);
static void pmcraid_process_ldn(struct pmcraid_cmd *cmd);

/**
 * pmcraid_send_hcam_cmd - send an initialized command block(HCAM) to IOA
 *
 * @cmd: initialized command block pointer
 *
 * Return Value
 *   none
 */
static void pmcraid_send_hcam_cmd(struct pmcraid_cmd *cmd)
{
        if (cmd->ioa_cb->ioarcb.cdb[1] == PMCRAID_HCAM_CODE_CONFIG_CHANGE)
                atomic_set(&(cmd->drv_inst->ccn.ignore), 0);
        else
                atomic_set(&(cmd->drv_inst->ldn.ignore), 0);

        pmcraid_send_cmd(cmd, cmd->cmd_done, 0, NULL);
}

/**
 * pmcraid_init_hcam - send an initialized command block(HCAM) to IOA
 *
 * @pinstance: pointer to adapter instance structure
 * @type: HCAM type
 *
 * Return Value
 *   pointer to initialized pmcraid_cmd structure or NULL
 */
static struct pmcraid_cmd *pmcraid_init_hcam
(
        struct pmcraid_instance *pinstance,
        u8 type
)
{
        struct pmcraid_cmd *cmd;
        struct pmcraid_ioarcb *ioarcb;
        struct pmcraid_ioadl_desc *ioadl;
        struct pmcraid_hostrcb *hcam;
        void (*cmd_done) (struct pmcraid_cmd *);
        dma_addr_t dma;
        int rcb_size;

        cmd = pmcraid_get_free_cmd(pinstance);

        if (!cmd) {
                pmcraid_err("no free command blocks for hcam\n");
                return cmd;
        }

        if (type == PMCRAID_HCAM_CODE_CONFIG_CHANGE) {
                rcb_size = sizeof(struct pmcraid_hcam_ccn_ext);
                cmd_done = pmcraid_process_ccn;
                dma = pinstance->ccn.baddr + PMCRAID_AEN_HDR_SIZE;
                hcam = &pinstance->ccn;
        } else {
                rcb_size = sizeof(struct pmcraid_hcam_ldn);
                cmd_done = pmcraid_process_ldn;
                dma = pinstance->ldn.baddr + PMCRAID_AEN_HDR_SIZE;
                hcam = &pinstance->ldn;
        }

        /* initialize command pointer used for HCAM registration */
        hcam->cmd = cmd;

        ioarcb = &cmd->ioa_cb->ioarcb;
        ioarcb->ioadl_bus_addr = cpu_to_le64((cmd->ioa_cb_bus_addr) +
                                        offsetof(struct pmcraid_ioarcb,
                                                add_data.u.ioadl[0]));
        ioarcb->ioadl_length = cpu_to_le32(sizeof(struct pmcraid_ioadl_desc));
        ioadl = ioarcb->add_data.u.ioadl;

        /* Initialize ioarcb */
        ioarcb->request_type = REQ_TYPE_HCAM;
        ioarcb->resource_handle = cpu_to_le32(PMCRAID_IOA_RES_HANDLE);
        ioarcb->cdb[0] = PMCRAID_HOST_CONTROLLED_ASYNC;
        ioarcb->cdb[1] = type;
        ioarcb->cdb[7] = (rcb_size >> 8) & 0xFF;
        ioarcb->cdb[8] = (rcb_size) & 0xFF;

        ioarcb->data_transfer_length = cpu_to_le32(rcb_size);

        ioadl[0].flags |= IOADL_FLAGS_READ_LAST;
        ioadl[0].data_len = cpu_to_le32(rcb_size);
        ioadl[0].address = cpu_to_le64(dma);

        cmd->cmd_done = cmd_done;
        return cmd;
}

/**
 * pmcraid_send_hcam - Send an HCAM to IOA
 * @pinstance: ioa config struct
 * @type: HCAM type
 *
 * This function will send a Host Controlled Async command to IOA.
 *
 * Return value:
 *      none
 */
static void pmcraid_send_hcam(struct pmcraid_instance *pinstance, u8 type)
{
        struct pmcraid_cmd *cmd = pmcraid_init_hcam(pinstance, type);
        pmcraid_send_hcam_cmd(cmd);
}


/**
 * pmcraid_prepare_cancel_cmd - prepares a command block to abort another
 *
 * @cmd: pointer to cmd that is used as cancelling command
 * @cmd_to_cancel: pointer to the command that needs to be cancelled
 */
static void pmcraid_prepare_cancel_cmd(
        struct pmcraid_cmd *cmd,
        struct pmcraid_cmd *cmd_to_cancel
)
{
        struct pmcraid_ioarcb *ioarcb = &cmd->ioa_cb->ioarcb;
        __be64 ioarcb_addr;

        /* IOARCB address of the command to be cancelled is given in
         * cdb[2]..cdb[9] is Big-Endian format. Note that length bits in
         * IOARCB address are not masked.
         */
        ioarcb_addr = cpu_to_be64(le64_to_cpu(cmd_to_cancel->ioa_cb->ioarcb.ioarcb_bus_addr));

        /* Get the resource handle to where the command to be aborted has been
         * sent.
         */
        ioarcb->resource_handle = cmd_to_cancel->ioa_cb->ioarcb.resource_handle;
        ioarcb->request_type = REQ_TYPE_IOACMD;
        memset(ioarcb->cdb, 0, PMCRAID_MAX_CDB_LEN);
        ioarcb->cdb[0] = PMCRAID_ABORT_CMD;

        memcpy(&(ioarcb->cdb[2]), &ioarcb_addr, sizeof(ioarcb_addr));
}

/**
 * pmcraid_cancel_hcam - sends ABORT task to abort a given HCAM
 *
 * @cmd: command to be used as cancelling command
 * @type: HCAM type
 * @cmd_done: op done function for the cancelling command
 */
static void pmcraid_cancel_hcam(
        struct pmcraid_cmd *cmd,
        u8 type,
        void (*cmd_done) (struct pmcraid_cmd *)
)
{
        struct pmcraid_instance *pinstance;
        struct pmcraid_hostrcb  *hcam;

        pinstance = cmd->drv_inst;
        hcam =  (type == PMCRAID_HCAM_CODE_LOG_DATA) ?
                &pinstance->ldn : &pinstance->ccn;

        /* prepare for cancelling previous hcam command. If the HCAM is
         * currently not pending with IOA, we would have hcam->cmd as non-null
         */
        if (hcam->cmd == NULL)
                return;

        pmcraid_prepare_cancel_cmd(cmd, hcam->cmd);

        /* writing to IOARRIN must be protected by host_lock, as mid-layer
         * schedule queuecommand while we are doing this
         */
        pmcraid_send_cmd(cmd, cmd_done,
                         PMCRAID_INTERNAL_TIMEOUT,
                         pmcraid_timeout_handler);
}

/**
 * pmcraid_cancel_ccn - cancel CCN HCAM already registered with IOA
 *
 * @cmd: command block to be used for cancelling the HCAM
 */
static void pmcraid_cancel_ccn(struct pmcraid_cmd *cmd)
{
        pmcraid_info("response for Cancel LDN CDB[0] = %x ioasc = %x\n",
                     cmd->ioa_cb->ioarcb.cdb[0],
                     le32_to_cpu(cmd->ioa_cb->ioasa.ioasc));

        pmcraid_reinit_cmdblk(cmd);

        pmcraid_cancel_hcam(cmd,
                            PMCRAID_HCAM_CODE_CONFIG_CHANGE,
                            pmcraid_ioa_shutdown);
}

/**
 * pmcraid_cancel_ldn - cancel LDN HCAM already registered with IOA
 *
 * @cmd: command block to be used for cancelling the HCAM
 */
static void pmcraid_cancel_ldn(struct pmcraid_cmd *cmd)
{
        pmcraid_cancel_hcam(cmd,
                            PMCRAID_HCAM_CODE_LOG_DATA,
                            pmcraid_cancel_ccn);
}

/**
 * pmcraid_expose_resource - check if the resource can be exposed to OS
 *
 * @fw_version: firmware version code
 * @cfgte: pointer to configuration table entry of the resource
 *
 * Return value:
 *      true if resource can be added to midlayer, false(0) otherwise
 */
static int pmcraid_expose_resource(u16 fw_version,
                                   struct pmcraid_config_table_entry *cfgte)
{
        int retval = 0;

        if (cfgte->resource_type == RES_TYPE_VSET) {
                if (fw_version <= PMCRAID_FW_VERSION_1)
                        retval = ((cfgte->unique_flags1 & 0x80) == 0);
                else
                        retval = ((cfgte->unique_flags0 & 0x80) == 0 &&
                                  (cfgte->unique_flags1 & 0x80) == 0);

        } else if (cfgte->resource_type == RES_TYPE_GSCSI)
                retval = (RES_BUS(cfgte->resource_address) !=
                                PMCRAID_VIRTUAL_ENCL_BUS_ID);
        return retval;
}

/* attributes supported by pmcraid_event_family */
enum {
        PMCRAID_AEN_ATTR_UNSPEC,
        PMCRAID_AEN_ATTR_EVENT,
        __PMCRAID_AEN_ATTR_MAX,
};
#define PMCRAID_AEN_ATTR_MAX (__PMCRAID_AEN_ATTR_MAX - 1)

/* commands supported by pmcraid_event_family */
enum {
        PMCRAID_AEN_CMD_UNSPEC,
        PMCRAID_AEN_CMD_EVENT,
        __PMCRAID_AEN_CMD_MAX,
};
#define PMCRAID_AEN_CMD_MAX (__PMCRAID_AEN_CMD_MAX - 1)

static struct genl_multicast_group pmcraid_mcgrps[] = {
        { .name = "events", /* not really used - see ID discussion below */ },
};

static struct genl_family pmcraid_event_family __ro_after_init = {
        .module = THIS_MODULE,
        .name = "pmcraid",
        .version = 1,
        .maxattr = PMCRAID_AEN_ATTR_MAX,
        .mcgrps = pmcraid_mcgrps,
        .n_mcgrps = ARRAY_SIZE(pmcraid_mcgrps),
};

/**
 * pmcraid_netlink_init - registers pmcraid_event_family
 *
 * Return value:
 *      0 if the pmcraid_event_family is successfully registered
 *      with netlink generic, non-zero otherwise
 */
static int __init pmcraid_netlink_init(void)
{
        int result;

        result = genl_register_family(&pmcraid_event_family);

        if (result)
                return result;

        pmcraid_info("registered NETLINK GENERIC group: %d\n",
                     pmcraid_event_family.id);

        return result;
}

/**
 * pmcraid_netlink_release - unregisters pmcraid_event_family
 *
 * Return value:
 *      none
 */
static void pmcraid_netlink_release(void)
{
        genl_unregister_family(&pmcraid_event_family);
}

/**
 * pmcraid_notify_aen - sends event msg to user space application
 * @pinstance: pointer to adapter instance structure
 * @type: HCAM type
 *
 * Return value:
 *      0 if success, error value in case of any failure.
 */
static int pmcraid_notify_aen(
        struct pmcraid_instance *pinstance,
        struct pmcraid_aen_msg  *aen_msg,
        u32    data_size
)
{
        struct sk_buff *skb;
        void *msg_header;
        u32  total_size, nla_genl_hdr_total_size;
        int result;

        aen_msg->hostno = (pinstance->host->unique_id << 16 |
                           MINOR(pinstance->cdev.dev));
        aen_msg->length = data_size;

        data_size += sizeof(*aen_msg);

        total_size = nla_total_size(data_size);
        /* Add GENL_HDR to total_size */
        nla_genl_hdr_total_size =
                (total_size + (GENL_HDRLEN +
                ((struct genl_family *)&pmcraid_event_family)->hdrsize)
                 + NLMSG_HDRLEN);
        skb = genlmsg_new(nla_genl_hdr_total_size, GFP_ATOMIC);


        if (!skb) {
                pmcraid_err("Failed to allocate aen data SKB of size: %x\n",
                             total_size);
                return -ENOMEM;
        }

        /* add the genetlink message header */
        msg_header = genlmsg_put(skb, 0, 0,
                                 &pmcraid_event_family, 0,
                                 PMCRAID_AEN_CMD_EVENT);
        if (!msg_header) {
                pmcraid_err("failed to copy command details\n");
                nlmsg_free(skb);
                return -ENOMEM;
        }

        result = nla_put(skb, PMCRAID_AEN_ATTR_EVENT, data_size, aen_msg);

        if (result) {
                pmcraid_err("failed to copy AEN attribute data\n");
                nlmsg_free(skb);
                return -EINVAL;
        }

        /* send genetlink multicast message to notify appplications */
        genlmsg_end(skb, msg_header);

        result = genlmsg_multicast(&pmcraid_event_family, skb,
                                   0, 0, GFP_ATOMIC);

        /* If there are no listeners, genlmsg_multicast may return non-zero
         * value.
         */
        if (result)
                pmcraid_info("error (%x) sending aen event message\n", result);
        return result;
}

/**
 * pmcraid_notify_ccn - notifies about CCN event msg to user space
 * @pinstance: pointer adapter instance structure
 *
 * Return value:
 *      0 if success, error value in case of any failure
 */
static int pmcraid_notify_ccn(struct pmcraid_instance *pinstance)
{
        return pmcraid_notify_aen(pinstance,
                                pinstance->ccn.msg,
                                le32_to_cpu(pinstance->ccn.hcam->data_len) +
                                sizeof(struct pmcraid_hcam_hdr));
}

/**
 * pmcraid_notify_ldn - notifies about CCN event msg to user space
 * @pinstance: pointer adapter instance structure
 *
 * Return value:
 *      0 if success, error value in case of any failure
 */
static int pmcraid_notify_ldn(struct pmcraid_instance *pinstance)
{
        return pmcraid_notify_aen(pinstance,
                                pinstance->ldn.msg,
                                le32_to_cpu(pinstance->ldn.hcam->data_len) +
                                sizeof(struct pmcraid_hcam_hdr));
}

/**
 * pmcraid_notify_ioastate - sends IOA state event msg to user space
 * @pinstance: pointer adapter instance structure
 * @evt: controller state event to be sent
 *
 * Return value:
 *      0 if success, error value in case of any failure
 */
static void pmcraid_notify_ioastate(struct pmcraid_instance *pinstance, u32 evt)
{
        pinstance->scn.ioa_state = evt;
        pmcraid_notify_aen(pinstance,
                          &pinstance->scn.msg,
                          sizeof(u32));
}

/**
 * pmcraid_handle_config_change - Handle a config change from the adapter
 * @pinstance: pointer to per adapter instance structure
 *
 * Return value:
 *  none
 */

static void pmcraid_handle_config_change(struct pmcraid_instance *pinstance)
{
        struct pmcraid_config_table_entry *cfg_entry;
        struct pmcraid_hcam_ccn *ccn_hcam;
        struct pmcraid_cmd *cmd;
        struct pmcraid_cmd *cfgcmd;
        struct pmcraid_resource_entry *res = NULL;
        unsigned long lock_flags;
        unsigned long host_lock_flags;
        u32 new_entry = 1;
        u32 hidden_entry = 0;
        u16 fw_version;
        int rc;

        ccn_hcam = (struct pmcraid_hcam_ccn *)pinstance->ccn.hcam;
        cfg_entry = &ccn_hcam->cfg_entry;
        fw_version = be16_to_cpu(pinstance->inq_data->fw_version);

        pmcraid_info("CCN(%x): %x timestamp: %llx type: %x lost: %x flags: %x \
                 res: %x:%x:%x:%x\n",
                 le32_to_cpu(pinstance->ccn.hcam->ilid),
                 pinstance->ccn.hcam->op_code,
                (le32_to_cpu(pinstance->ccn.hcam->timestamp1) |
                ((le32_to_cpu(pinstance->ccn.hcam->timestamp2) & 0xffffffffLL) << 32)),
                 pinstance->ccn.hcam->notification_type,
                 pinstance->ccn.hcam->notification_lost,
                 pinstance->ccn.hcam->flags,
                 pinstance->host->unique_id,
                 RES_IS_VSET(*cfg_entry) ? PMCRAID_VSET_BUS_ID :
                 (RES_IS_GSCSI(*cfg_entry) ? PMCRAID_PHYS_BUS_ID :
                        RES_BUS(cfg_entry->resource_address)),
                 RES_IS_VSET(*cfg_entry) ?
                        (fw_version <= PMCRAID_FW_VERSION_1 ?
                                cfg_entry->unique_flags1 :
                                le16_to_cpu(cfg_entry->array_id) & 0xFF) :
                        RES_TARGET(cfg_entry->resource_address),
                 RES_LUN(cfg_entry->resource_address));


        /* If this HCAM indicates a lost notification, read the config table */
        if (pinstance->ccn.hcam->notification_lost) {
                cfgcmd = pmcraid_get_free_cmd(pinstance);
                if (cfgcmd) {
                        pmcraid_info("lost CCN, reading config table\b");
                        pinstance->reinit_cfg_table = 1;
                        pmcraid_querycfg(cfgcmd);
                } else {
                        pmcraid_err("lost CCN, no free cmd for querycfg\n");
                }
                goto out_notify_apps;
        }

        /* If this resource is not going to be added to mid-layer, just notify
         * applications and return. If this notification is about hiding a VSET
         * resource, check if it was exposed already.
         */
        if (pinstance->ccn.hcam->notification_type ==
            NOTIFICATION_TYPE_ENTRY_CHANGED &&
            cfg_entry->resource_type == RES_TYPE_VSET) {
                hidden_entry = (cfg_entry->unique_flags1 & 0x80) != 0;
        } else if (!pmcraid_expose_resource(fw_version, cfg_entry)) {
                goto out_notify_apps;
        }

        spin_lock_irqsave(&pinstance->resource_lock, lock_flags);
        list_for_each_entry(res, &pinstance->used_res_q, queue) {
                rc = memcmp(&res->cfg_entry.resource_address,
                            &cfg_entry->resource_address,
                            sizeof(cfg_entry->resource_address));
                if (!rc) {
                        new_entry = 0;
                        break;
                }
        }

        if (new_entry) {

                if (hidden_entry) {
                        spin_unlock_irqrestore(&pinstance->resource_lock,
                                                lock_flags);
                        goto out_notify_apps;
                }

                /* If there are more number of resources than what driver can
                 * manage, do not notify the applications about the CCN. Just
                 * ignore this notifications and re-register the same HCAM
                 */
                if (list_empty(&pinstance->free_res_q)) {
                        spin_unlock_irqrestore(&pinstance->resource_lock,
                                                lock_flags);
                        pmcraid_err("too many resources attached\n");
                        spin_lock_irqsave(pinstance->host->host_lock,
                                          host_lock_flags);
                        pmcraid_send_hcam(pinstance,
                                          PMCRAID_HCAM_CODE_CONFIG_CHANGE);
                        spin_unlock_irqrestore(pinstance->host->host_lock,
                                               host_lock_flags);
                        return;
                }

                res = list_entry(pinstance->free_res_q.next,
                                 struct pmcraid_resource_entry, queue);

                list_del(&res->queue);
                res->scsi_dev = NULL;
                res->reset_progress = 0;
                list_add_tail(&res->queue, &pinstance->used_res_q);
        }

        memcpy(&res->cfg_entry, cfg_entry, pinstance->config_table_entry_size);

        if (pinstance->ccn.hcam->notification_type ==
            NOTIFICATION_TYPE_ENTRY_DELETED || hidden_entry) {
                if (res->scsi_dev) {
                        if (fw_version <= PMCRAID_FW_VERSION_1)
                                res->cfg_entry.unique_flags1 &= 0x7F;
                        else
                                res->cfg_entry.array_id &= cpu_to_le16(0xFF);
                        res->change_detected = RES_CHANGE_DEL;
                        res->cfg_entry.resource_handle =
                                PMCRAID_INVALID_RES_HANDLE;
                        schedule_work(&pinstance->worker_q);
                } else {
                        /* This may be one of the non-exposed resources */
                        list_move_tail(&res->queue, &pinstance->free_res_q);
                }
        } else if (!res->scsi_dev) {
                res->change_detected = RES_CHANGE_ADD;
                schedule_work(&pinstance->worker_q);
        }
        spin_unlock_irqrestore(&pinstance->resource_lock, lock_flags);

out_notify_apps:

        /* Notify configuration changes to registered applications.*/
        if (!pmcraid_disable_aen)
                pmcraid_notify_ccn(pinstance);

        cmd = pmcraid_init_hcam(pinstance, PMCRAID_HCAM_CODE_CONFIG_CHANGE);
        if (cmd)
                pmcraid_send_hcam_cmd(cmd);
}

/**
 * pmcraid_get_error_info - return error string for an ioasc
 * @ioasc: ioasc code
 * Return Value
 *       none
 */
static struct pmcraid_ioasc_error *pmcraid_get_error_info(u32 ioasc)
{
        int i;
        for (i = 0; i < ARRAY_SIZE(pmcraid_ioasc_error_table); i++) {
                if (pmcraid_ioasc_error_table[i].ioasc_code == ioasc)
                        return &pmcraid_ioasc_error_table[i];
        }
        return NULL;
}

/**
 * pmcraid_ioasc_logger - log IOASC information based user-settings
 * @ioasc: ioasc code
 * @cmd: pointer to command that resulted in 'ioasc'
 */
static void pmcraid_ioasc_logger(u32 ioasc, struct pmcraid_cmd *cmd)
{
        struct pmcraid_ioasc_error *error_info = pmcraid_get_error_info(ioasc);

        if (error_info == NULL ||
                cmd->drv_inst->current_log_level < error_info->log_level)
                return;

        /* log the error string */
        pmcraid_err("cmd [%x] for resource %x failed with %x(%s)\n",
                cmd->ioa_cb->ioarcb.cdb[0],
                le32_to_cpu(cmd->ioa_cb->ioarcb.resource_handle),
                ioasc, error_info->error_string);
}

/**
 * pmcraid_handle_error_log - Handle a config change (error log) from the IOA
 *
 * @pinstance: pointer to per adapter instance structure
 *
 * Return value:
 *  none
 */
static void pmcraid_handle_error_log(struct pmcraid_instance *pinstance)
{
        struct pmcraid_hcam_ldn *hcam_ldn;
        u32 ioasc;

        hcam_ldn = (struct pmcraid_hcam_ldn *)pinstance->ldn.hcam;

        pmcraid_info
                ("LDN(%x): %x type: %x lost: %x flags: %x overlay id: %x\n",
                 pinstance->ldn.hcam->ilid,
                 pinstance->ldn.hcam->op_code,
                 pinstance->ldn.hcam->notification_type,
                 pinstance->ldn.hcam->notification_lost,
                 pinstance->ldn.hcam->flags,
                 pinstance->ldn.hcam->overlay_id);

        /* log only the errors, no need to log informational log entries */
        if (pinstance->ldn.hcam->notification_type !=
            NOTIFICATION_TYPE_ERROR_LOG)
                return;

        if (pinstance->ldn.hcam->notification_lost ==
            HOSTRCB_NOTIFICATIONS_LOST)
                dev_info(&pinstance->pdev->dev, "Error notifications lost\n");

        ioasc = le32_to_cpu(hcam_ldn->error_log.fd_ioasc);

        if (ioasc == PMCRAID_IOASC_UA_BUS_WAS_RESET ||
                ioasc == PMCRAID_IOASC_UA_BUS_WAS_RESET_BY_OTHER) {
                dev_info(&pinstance->pdev->dev,
                        "UnitAttention due to IOA Bus Reset\n");
                scsi_report_bus_reset(
                        pinstance->host,
                        RES_BUS(hcam_ldn->error_log.fd_ra));
        }

        return;
}

/**
 * pmcraid_process_ccn - Op done function for a CCN.
 * @cmd: pointer to command struct
 *
 * This function is the op done function for a configuration
 * change notification
 *
 * Return value:
 * none
 */
static void pmcraid_process_ccn(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u32 ioasc = le32_to_cpu(cmd->ioa_cb->ioasa.ioasc);
        unsigned long lock_flags;

        pinstance->ccn.cmd = NULL;
        pmcraid_return_cmd(cmd);

        /* If driver initiated IOA reset happened while this hcam was pending
         * with IOA, or IOA bringdown sequence is in progress, no need to
         * re-register the hcam
         */
        if (ioasc == PMCRAID_IOASC_IOA_WAS_RESET ||
            atomic_read(&pinstance->ccn.ignore) == 1) {
                return;
        } else if (ioasc) {
                dev_info(&pinstance->pdev->dev,
                        "Host RCB (CCN) failed with IOASC: 0x%08X\n", ioasc);
                spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
                pmcraid_send_hcam(pinstance, PMCRAID_HCAM_CODE_CONFIG_CHANGE);
                spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
        } else {
                pmcraid_handle_config_change(pinstance);
        }
}

/**
 * pmcraid_process_ldn - op done function for an LDN
 * @cmd: pointer to command block
 *
 * Return value
 *   none
 */
static void pmcraid_initiate_reset(struct pmcraid_instance *);
static void pmcraid_set_timestamp(struct pmcraid_cmd *cmd);

static void pmcraid_process_ldn(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        struct pmcraid_hcam_ldn *ldn_hcam =
                        (struct pmcraid_hcam_ldn *)pinstance->ldn.hcam;
        u32 ioasc = le32_to_cpu(cmd->ioa_cb->ioasa.ioasc);
        u32 fd_ioasc = le32_to_cpu(ldn_hcam->error_log.fd_ioasc);
        unsigned long lock_flags;

        /* return the command block back to freepool */
        pinstance->ldn.cmd = NULL;
        pmcraid_return_cmd(cmd);

        /* If driver initiated IOA reset happened while this hcam was pending
         * with IOA, no need to re-register the hcam as reset engine will do it
         * once reset sequence is complete
         */
        if (ioasc == PMCRAID_IOASC_IOA_WAS_RESET ||
            atomic_read(&pinstance->ccn.ignore) == 1) {
                return;
        } else if (!ioasc) {
                pmcraid_handle_error_log(pinstance);
                if (fd_ioasc == PMCRAID_IOASC_NR_IOA_RESET_REQUIRED) {
                        spin_lock_irqsave(pinstance->host->host_lock,
                                          lock_flags);
                        pmcraid_initiate_reset(pinstance);
                        spin_unlock_irqrestore(pinstance->host->host_lock,
                                               lock_flags);
                        return;
                }
                if (fd_ioasc == PMCRAID_IOASC_TIME_STAMP_OUT_OF_SYNC) {
                        pinstance->timestamp_error = 1;
                        pmcraid_set_timestamp(cmd);
                }
        } else {
                dev_info(&pinstance->pdev->dev,
                        "Host RCB(LDN) failed with IOASC: 0x%08X\n", ioasc);
        }
        /* send netlink message for HCAM notification if enabled */
        if (!pmcraid_disable_aen)
                pmcraid_notify_ldn(pinstance);

        cmd = pmcraid_init_hcam(pinstance, PMCRAID_HCAM_CODE_LOG_DATA);
        if (cmd)
                pmcraid_send_hcam_cmd(cmd);
}

/**
 * pmcraid_register_hcams - register HCAMs for CCN and LDN
 *
 * @pinstance: pointer per adapter instance structure
 *
 * Return Value
 *   none
 */
static void pmcraid_register_hcams(struct pmcraid_instance *pinstance)
{
        pmcraid_send_hcam(pinstance, PMCRAID_HCAM_CODE_CONFIG_CHANGE);
        pmcraid_send_hcam(pinstance, PMCRAID_HCAM_CODE_LOG_DATA);
}

/**
 * pmcraid_unregister_hcams - cancel HCAMs registered already
 * @cmd: pointer to command used as part of reset sequence
 */
static void pmcraid_unregister_hcams(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;

        /* During IOA bringdown, HCAM gets fired and tasklet proceeds with
         * handling hcam response though it is not necessary. In order to
         * prevent this, set 'ignore', so that bring-down sequence doesn't
         * re-send any more hcams
         */
        atomic_set(&pinstance->ccn.ignore, 1);
        atomic_set(&pinstance->ldn.ignore, 1);

        /* If adapter reset was forced as part of runtime reset sequence,
         * start the reset sequence. Reset will be triggered even in case
         * IOA unit_check.
         */
        if ((pinstance->force_ioa_reset && !pinstance->ioa_bringdown) ||
             pinstance->ioa_unit_check) {
                pinstance->force_ioa_reset = 0;
                pinstance->ioa_unit_check = 0;
                pinstance->ioa_state = IOA_STATE_IN_RESET_ALERT;
                pmcraid_reset_alert(cmd);
                return;
        }

        /* Driver tries to cancel HCAMs by sending ABORT TASK for each HCAM
         * one after the other. So CCN cancellation will be triggered by
         * pmcraid_cancel_ldn itself.
         */
        pmcraid_cancel_ldn(cmd);
}

/**
 * pmcraid_reset_enable_ioa - re-enable IOA after a hard reset
 * @pinstance: pointer to adapter instance structure
 * Return Value
 *  1 if TRANSITION_TO_OPERATIONAL is active, otherwise 0
 */
static void pmcraid_reinit_buffers(struct pmcraid_instance *);

static int pmcraid_reset_enable_ioa(struct pmcraid_instance *pinstance)
{
        u32 intrs;

        pmcraid_reinit_buffers(pinstance);
        intrs = pmcraid_read_interrupts(pinstance);

        pmcraid_enable_interrupts(pinstance, PMCRAID_PCI_INTERRUPTS);

        if (intrs & INTRS_TRANSITION_TO_OPERATIONAL) {
                if (!pinstance->interrupt_mode) {
                        iowrite32(INTRS_TRANSITION_TO_OPERATIONAL,
                                pinstance->int_regs.
                                ioa_host_interrupt_mask_reg);
                        iowrite32(INTRS_TRANSITION_TO_OPERATIONAL,
                                pinstance->int_regs.ioa_host_interrupt_clr_reg);
                }
                return 1;
        } else {
                return 0;
        }
}

/**
 * pmcraid_soft_reset - performs a soft reset and makes IOA become ready
 * @cmd : pointer to reset command block
 *
 * Return Value
 *      none
 */
static void pmcraid_soft_reset(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u32 int_reg;
        u32 doorbell;

        /* There will be an interrupt when Transition to Operational bit is
         * set so tasklet would execute next reset task. The timeout handler
         * would re-initiate a reset
         */
        cmd->cmd_done = pmcraid_ioa_reset;
        cmd->timer.data = (unsigned long)cmd;
        cmd->timer.expires = jiffies +
                             msecs_to_jiffies(PMCRAID_TRANSOP_TIMEOUT);
        cmd->timer.function = (void (*)(unsigned long))pmcraid_timeout_handler;

        if (!timer_pending(&cmd->timer))
                add_timer(&cmd->timer);

        /* Enable destructive diagnostics on IOA if it is not yet in
         * operational state
         */
        doorbell = DOORBELL_RUNTIME_RESET |
                   DOORBELL_ENABLE_DESTRUCTIVE_DIAGS;

        /* Since we do RESET_ALERT and Start BIST we have to again write
         * MSIX Doorbell to indicate the interrupt mode
         */
        if (pinstance->interrupt_mode) {
                iowrite32(DOORBELL_INTR_MODE_MSIX,
                          pinstance->int_regs.host_ioa_interrupt_reg);
                ioread32(pinstance->int_regs.host_ioa_interrupt_reg);
        }

        iowrite32(doorbell, pinstance->int_regs.host_ioa_interrupt_reg);
        ioread32(pinstance->int_regs.host_ioa_interrupt_reg),
        int_reg = ioread32(pinstance->int_regs.ioa_host_interrupt_reg);

        pmcraid_info("Waiting for IOA to become operational %x:%x\n",
                     ioread32(pinstance->int_regs.host_ioa_interrupt_reg),
                     int_reg);
}

/**
 * pmcraid_get_dump - retrieves IOA dump in case of Unit Check interrupt
 *
 * @pinstance: pointer to adapter instance structure
 *
 * Return Value
 *      none
 */
static void pmcraid_get_dump(struct pmcraid_instance *pinstance)
{
        pmcraid_info("%s is not yet implemented\n", __func__);

}

/**
 * pmcraid_fail_outstanding_cmds - Fails all outstanding ops.
 * @pinstance: pointer to adapter instance structure
 *
 * This function fails all outstanding ops. If they are submitted to IOA
 * already, it sends cancel all messages if IOA is still accepting IOARCBs,
 * otherwise just completes the commands and returns the cmd blocks to free
 * pool.
 *
 * Return value:
 *       none
 */
static void pmcraid_fail_outstanding_cmds(struct pmcraid_instance *pinstance)
{
        struct pmcraid_cmd *cmd, *temp;
        unsigned long lock_flags;

        /* pending command list is protected by pending_pool_lock. Its
         * traversal must be done as within this lock
         */
        spin_lock_irqsave(&pinstance->pending_pool_lock, lock_flags);
        list_for_each_entry_safe(cmd, temp, &pinstance->pending_cmd_pool,
                                 free_list) {
                list_del(&cmd->free_list);
                spin_unlock_irqrestore(&pinstance->pending_pool_lock,
                                        lock_flags);
                cmd->ioa_cb->ioasa.ioasc =
                        cpu_to_le32(PMCRAID_IOASC_IOA_WAS_RESET);
                cmd->ioa_cb->ioasa.ilid =
                        cpu_to_le32(PMCRAID_DRIVER_ILID);

                /* In case the command timer is still running */
                del_timer(&cmd->timer);

                /* If this is an IO command, complete it by invoking scsi_done
                 * function. If this is one of the internal commands other
                 * than pmcraid_ioa_reset and HCAM commands invoke cmd_done to
                 * complete it
                 */
                if (cmd->scsi_cmd) {

                        struct scsi_cmnd *scsi_cmd = cmd->scsi_cmd;
                        __le32 resp = cmd->ioa_cb->ioarcb.response_handle;

                        scsi_cmd->result |= DID_ERROR << 16;

                        scsi_dma_unmap(scsi_cmd);
                        pmcraid_return_cmd(cmd);

                        pmcraid_info("failing(%d) CDB[0] = %x result: %x\n",
                                     le32_to_cpu(resp) >> 2,
                                     cmd->ioa_cb->ioarcb.cdb[0],
                                     scsi_cmd->result);
                        scsi_cmd->scsi_done(scsi_cmd);
                } else if (cmd->cmd_done == pmcraid_internal_done ||
                           cmd->cmd_done == pmcraid_erp_done) {
                        cmd->cmd_done(cmd);
                } else if (cmd->cmd_done != pmcraid_ioa_reset &&
                           cmd->cmd_done != pmcraid_ioa_shutdown_done) {
                        pmcraid_return_cmd(cmd);
                }

                atomic_dec(&pinstance->outstanding_cmds);
                spin_lock_irqsave(&pinstance->pending_pool_lock, lock_flags);
        }

        spin_unlock_irqrestore(&pinstance->pending_pool_lock, lock_flags);
}

/**
 * pmcraid_ioa_reset - Implementation of IOA reset logic
 *
 * @cmd: pointer to the cmd block to be used for entire reset process
 *
 * This function executes most of the steps required for IOA reset. This gets
 * called by user threads (modprobe/insmod/rmmod) timer, tasklet and midlayer's
 * 'eh_' thread. Access to variables used for controlling the reset sequence is
 * synchronized using host lock. Various functions called during reset process
 * would make use of a single command block, pointer to which is also stored in
 * adapter instance structure.
 *
 * Return Value
 *       None
 */
static void pmcraid_ioa_reset(struct pmcraid_cmd *cmd)
{
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        u8 reset_complete = 0;

        pinstance->ioa_reset_in_progress = 1;

        if (pinstance->reset_cmd != cmd) {
                pmcraid_err("reset is called with different command block\n");
                pinstance->reset_cmd = cmd;
        }

        pmcraid_info("reset_engine: state = %d, command = %p\n",
                      pinstance->ioa_state, cmd);

        switch (pinstance->ioa_state) {

        case IOA_STATE_DEAD:
                /* If IOA is offline, whatever may be the reset reason, just
                 * return. callers might be waiting on the reset wait_q, wake
                 * up them
                 */
                pmcraid_err("IOA is offline no reset is possible\n");
                reset_complete = 1;
                break;

        case IOA_STATE_IN_BRINGDOWN:
                /* we enter here, once ioa shutdown command is processed by IOA
                 * Alert IOA for a possible reset. If reset alert fails, IOA
                 * goes through hard-reset
                 */
                pmcraid_disable_interrupts(pinstance, ~0);
                pinstance->ioa_state = IOA_STATE_IN_RESET_ALERT;
                pmcraid_reset_alert(cmd);
                break;

        case IOA_STATE_UNKNOWN:
                /* We may be called during probe or resume. Some pre-processing
                 * is required for prior to reset
                 */
                scsi_block_requests(pinstance->host);

                /* If asked to reset while IOA was processing responses or
                 * there are any error responses then IOA may require
                 * hard-reset.
                 */
                if (pinstance->ioa_hard_reset == 0) {
                        if (ioread32(pinstance->ioa_status) &
                            INTRS_TRANSITION_TO_OPERATIONAL) {
                                pmcraid_info("sticky bit set, bring-up\n");
                                pinstance->ioa_state = IOA_STATE_IN_BRINGUP;
                                pmcraid_reinit_cmdblk(cmd);
                                pmcraid_identify_hrrq(cmd);
                        } else {
                                pinstance->ioa_state = IOA_STATE_IN_SOFT_RESET;
                                pmcraid_soft_reset(cmd);
                        }
                } else {
                        /* Alert IOA of a possible reset and wait for critical
                         * operation in progress bit to reset
                         */
                        pinstance->ioa_state = IOA_STATE_IN_RESET_ALERT;
                        pmcraid_reset_alert(cmd);
                }
                break;

        case IOA_STATE_IN_RESET_ALERT:
                /* If critical operation in progress bit is reset or wait gets
                 * timed out, reset proceeds with starting BIST on the IOA.
                 * pmcraid_ioa_hard_reset keeps a count of reset attempts. If
                 * they are 3 or more, reset engine marks IOA dead and returns
                 */
                pinstance->ioa_state = IOA_STATE_IN_HARD_RESET;
                pmcraid_start_bist(cmd);
                break;

        case IOA_STATE_IN_HARD_RESET:
                pinstance->ioa_reset_attempts++;

                /* retry reset if we haven't reached maximum allowed limit */
                if (pinstance->ioa_reset_attempts > PMCRAID_RESET_ATTEMPTS) {
                        pinstance->ioa_reset_attempts = 0;
                        pmcraid_err("IOA didn't respond marking it as dead\n");
                        pinstance->ioa_state = IOA_STATE_DEAD;

                        if (pinstance->ioa_bringdown)
                                pmcraid_notify_ioastate(pinstance,
                                        PMC_DEVICE_EVENT_SHUTDOWN_FAILED);
                        else
                                pmcraid_notify_ioastate(pinstance,
                                                PMC_DEVICE_EVENT_RESET_FAILED);
                        reset_complete = 1;
                        break;
                }

                /* Once either bist or pci reset is done, restore PCI config
                 * space. If this fails, proceed with hard reset again
                 */
                pci_restore_state(pinstance->pdev);

                /* fail all pending commands */
                pmcraid_fail_outstanding_cmds(pinstance);

                /* check if unit check is active, if so extract dump */
                if (pinstance->ioa_unit_check) {
                        pmcraid_info("unit check is active\n");
                        pinstance->ioa_unit_check = 0;
                        pmcraid_get_dump(pinstance);
                        pinstance->ioa_reset_attempts--;
                        pinstance->ioa_state = IOA_STATE_IN_RESET_ALERT;
                        pmcraid_reset_alert(cmd);
                        break;
                }

                /* if the reset reason is to bring-down the ioa, we might be
                 * done with the reset restore pci_config_space and complete
                 * the reset
                 */
                if (pinstance->ioa_bringdown) {
                        pmcraid_info("bringing down the adapter\n");
                        pinstance->ioa_shutdown_type = SHUTDOWN_NONE;
                        pinstance->ioa_bringdown = 0;
                        pinstance->ioa_state = IOA_STATE_UNKNOWN;
                        pmcraid_notify_ioastate(pinstance,
                                        PMC_DEVICE_EVENT_SHUTDOWN_SUCCESS);
                        reset_complete = 1;
                } else {
                        /* bring-up IOA, so proceed with soft reset
                         * Reinitialize hrrq_buffers and their indices also
                         * enable interrupts after a pci_restore_state
                         */
                        if (pmcraid_reset_enable_ioa(pinstance)) {
                                pinstance->ioa_state = IOA_STATE_IN_BRINGUP;
                                pmcraid_info("bringing up the adapter\n");
                                pmcraid_reinit_cmdblk(cmd);
                                pmcraid_identify_hrrq(cmd);
                        } else {
                                pinstance->ioa_state = IOA_STATE_IN_SOFT_RESET;
                                pmcraid_soft_reset(cmd);
                        }
                }
                break;

        case IOA_STATE_IN_SOFT_RESET:
                /* TRANSITION TO OPERATIONAL is on so start initialization
                 * sequence
                 */
                pmcraid_info("In softreset proceeding with bring-up\n");
                pinstance->ioa_state = IOA_STATE_IN_BRINGUP;

                /* Initialization commands start with HRRQ identification. From
                 * now on tasklet completes most of the commands as IOA is up
                 * and intrs are enabled
                 */
                pmcraid_identify_hrrq(cmd);
                break;

        case IOA_STATE_IN_BRINGUP:
                /* we are done with bringing up of IOA, change the ioa_state to
                 * operational and wake up any waiters
                 */
                pinstance->ioa_state = IOA_STATE_OPERATIONAL;
                reset_complete = 1;
                break;

        case IOA_STATE_OPERATIONAL:
        default:
                /* When IOA is operational and a reset is requested, check for
                 * the reset reason. If reset is to bring down IOA, unregister
                 * HCAMs and initiate shutdown; if adapter reset is forced then
                 * restart reset sequence again
                 */
                if (pinstance->ioa_shutdown_type == SHUTDOWN_NONE &&
                    pinstance->force_ioa_reset == 0) {
                        pmcraid_notify_ioastate(pinstance,
                                                PMC_DEVICE_EVENT_RESET_SUCCESS);
                        reset_complete = 1;
                } else {
                        if (pinstance->ioa_shutdown_type != SHUTDOWN_NONE)
                                pinstance->ioa_state = IOA_STATE_IN_BRINGDOWN;
                        pmcraid_reinit_cmdblk(cmd);
                        pmcraid_unregister_hcams(cmd);
                }
                break;
        }

        /* reset will be completed if ioa_state is either DEAD or UNKNOWN or
         * OPERATIONAL. Reset all control variables used during reset, wake up
         * any waiting threads and let the SCSI mid-layer send commands. Note
         * that host_lock must be held before invoking scsi_report_bus_reset.
         */
        if (reset_complete) {
                pinstance->ioa_reset_in_progress = 0;
                pinstance->ioa_reset_attempts = 0;
                pinstance->reset_cmd = NULL;
                pinstance->ioa_shutdown_type = SHUTDOWN_NONE;
                pinstance->ioa_bringdown = 0;
                pmcraid_return_cmd(cmd);

                /* If target state is to bring up the adapter, proceed with
                 * hcam registration and resource exposure to mid-layer.
                 */
                if (pinstance->ioa_state == IOA_STATE_OPERATIONAL)
                        pmcraid_register_hcams(pinstance);

                wake_up_all(&pinstance->reset_wait_q);
        }

        return;
}

/**
 * pmcraid_initiate_reset - initiates reset sequence. This is called from
 * ISR/tasklet during error interrupts including IOA unit check. If reset
 * is already in progress, it just returns, otherwise initiates IOA reset
 * to bring IOA up to operational state.
 *
 * @pinstance: pointer to adapter instance structure
 *
 * Return value
 *       none
 */
static void pmcraid_initiate_reset(struct pmcraid_instance *pinstance)
{
        struct pmcraid_cmd *cmd;

        /* If the reset is already in progress, just return, otherwise start
         * reset sequence and return
         */
        if (!pinstance->ioa_reset_in_progress) {
                scsi_block_requests(pinstance->host);
                cmd = pmcraid_get_free_cmd(pinstance);

                if (cmd == NULL) {
                        pmcraid_err("no cmnd blocks for initiate_reset\n");
                        return;
                }

                pinstance->ioa_shutdown_type = SHUTDOWN_NONE;
                pinstance->reset_cmd = cmd;
                pinstance->force_ioa_reset = 1;
                pmcraid_notify_ioastate(pinstance,
                                        PMC_DEVICE_EVENT_RESET_START);
                pmcraid_ioa_reset(cmd);
        }
}

/**
 * pmcraid_reset_reload - utility routine for doing IOA reset either to bringup
 *                        or bringdown IOA
 * @pinstance: pointer adapter instance structure
 * @shutdown_type: shutdown type to be used NONE, NORMAL or ABRREV
 * @target_state: expected target state after reset
 *
 * Note: This command initiates reset and waits for its completion. Hence this
 * should not be called from isr/timer/tasklet functions (timeout handlers,
 * error response handlers and interrupt handlers).
 *
 * Return Value
 *       1 in case ioa_state is not target_state, 0 otherwise.
 */
static int pmcraid_reset_reload(
        struct pmcraid_instance *pinstance,
        u8 shutdown_type,
        u8 target_state
)
{
        struct pmcraid_cmd *reset_cmd = NULL;
        unsigned long lock_flags;
        int reset = 1;

        spin_lock_irqsave(pinstance->host->host_lock, lock_flags);

        if (pinstance->ioa_reset_in_progress) {
                pmcraid_info("reset_reload: reset is already in progress\n");

                spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);

                wait_event(pinstance->reset_wait_q,
                           !pinstance->ioa_reset_in_progress);

                spin_lock_irqsave(pinstance->host->host_lock, lock_flags);

                if (pinstance->ioa_state == IOA_STATE_DEAD) {
                        pmcraid_info("reset_reload: IOA is dead\n");
                        goto out_unlock;
                }

                if (pinstance->ioa_state == target_state) {
                        reset = 0;
                        goto out_unlock;
                }
        }

        pmcraid_info("reset_reload: proceeding with reset\n");
        scsi_block_requests(pinstance->host);
        reset_cmd = pmcraid_get_free_cmd(pinstance);
        if (reset_cmd == NULL) {
                pmcraid_err("no free cmnd for reset_reload\n");
                goto out_unlock;
        }

        if (shutdown_type == SHUTDOWN_NORMAL)
                pinstance->ioa_bringdown = 1;

        pinstance->ioa_shutdown_type = shutdown_type;
        pinstance->reset_cmd = reset_cmd;
        pinstance->force_ioa_reset = reset;
        pmcraid_info("reset_reload: initiating reset\n");
        pmcraid_ioa_reset(reset_cmd);
        spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
        pmcraid_info("reset_reload: waiting for reset to complete\n");
        wait_event(pinstance->reset_wait_q,
                   !pinstance->ioa_reset_in_progress);

        pmcraid_info("reset_reload: reset is complete !!\n");
        scsi_unblock_requests(pinstance->host);
        return pinstance->ioa_state != target_state;

out_unlock:
        spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
        return reset;
}

/**
 * pmcraid_reset_bringdown - wrapper over pmcraid_reset_reload to bringdown IOA
 *
 * @pinstance: pointer to adapter instance structure
 *
 * Return Value
 *       whatever is returned from pmcraid_reset_reload
 */
static int pmcraid_reset_bringdown(struct pmcraid_instance *pinstance)
{
        return pmcraid_reset_reload(pinstance,
                                    SHUTDOWN_NORMAL,
                                    IOA_STATE_UNKNOWN);
}

/**
 * pmcraid_reset_bringup - wrapper over pmcraid_reset_reload to bring up IOA
 *
 * @pinstance: pointer to adapter instance structure
 *
 * Return Value
 *       whatever is returned from pmcraid_reset_reload
 */
static int pmcraid_reset_bringup(struct pmcraid_instance *pinstance)
{
        pmcraid_notify_ioastate(pinstance, PMC_DEVICE_EVENT_RESET_START);

        return pmcraid_reset_reload(pinstance,
                                    SHUTDOWN_NONE,
                                    IOA_STATE_OPERATIONAL);
}

/**
 * pmcraid_request_sense - Send request sense to a device
 * @cmd: pmcraid command struct
 *
 * This function sends a request sense to a device as a result of a check
 * condition. This method re-uses the same command block that failed earlier.
 */
static void pmcraid_request_sense(struct pmcraid_cmd *cmd)
{
        struct pmcraid_ioarcb *ioarcb = &cmd->ioa_cb->ioarcb;
        struct pmcraid_ioadl_desc *ioadl = ioarcb->add_data.u.ioadl;

        /* allocate DMAable memory for sense buffers */
        cmd->sense_buffer = pci_alloc_consistent(cmd->drv_inst->pdev,
                                                 SCSI_SENSE_BUFFERSIZE,
                                                 &cmd->sense_buffer_dma);

        if (cmd->sense_buffer == NULL) {
                pmcraid_err
                        ("couldn't allocate sense buffer for request sense\n");
                pmcraid_erp_done(cmd);
                return;
        }

        /* re-use the command block */
        memset(&cmd->ioa_cb->ioasa, 0, sizeof(struct pmcraid_ioasa));
        memset(ioarcb->cdb, 0, PMCRAID_MAX_CDB_LEN);
        ioarcb->request_flags0 = (SYNC_COMPLETE |
                                  NO_LINK_DESCS |
                                  INHIBIT_UL_CHECK);
        ioarcb->request_type = REQ_TYPE_SCSI;
        ioarcb->cdb[0] = REQUEST_SENSE;
        ioarcb->cdb[4] = SCSI_SENSE_BUFFERSIZE;

        ioarcb->ioadl_bus_addr = cpu_to_le64((cmd->ioa_cb_bus_addr) +
                                        offsetof(struct pmcraid_ioarcb,
                                                add_data.u.ioadl[0]));
        ioarcb->ioadl_length = cpu_to_le32(sizeof(struct pmcraid_ioadl_desc));

        ioarcb->data_transfer_length = cpu_to_le32(SCSI_SENSE_BUFFERSIZE);

        ioadl->address = cpu_to_le64(cmd->sense_buffer_dma);
        ioadl->data_len = cpu_to_le32(SCSI_SENSE_BUFFERSIZE);
        ioadl->flags = IOADL_FLAGS_LAST_DESC;

        /* request sense might be called as part of error response processing
         * which runs in tasklets context. It is possible that mid-layer might
         * schedule queuecommand during this time, hence, writting to IOARRIN
         * must be protect by host_lock
         */
        pmcraid_send_cmd(cmd, pmcraid_erp_done,
                         PMCRAID_REQUEST_SENSE_TIMEOUT,
                         pmcraid_timeout_handler);
}

/**
 * pmcraid_cancel_all - cancel all outstanding IOARCBs as part of error recovery
 * @cmd: command that failed
 * @sense: true if request_sense is required after cancel all
 *
 * This function sends a cancel all to a device to clear the queue.
 */
static void pmcraid_cancel_all(struct pmcraid_cmd *cmd, u32 sense)
{
        struct scsi_cmnd *scsi_cmd = cmd->scsi_cmd;
        struct pmcraid_ioarcb *ioarcb = &cmd->ioa_cb->ioarcb;
        struct pmcraid_resource_entry *res = scsi_cmd->device->hostdata;
        void (*cmd_done) (struct pmcraid_cmd *) = sense ? pmcraid_erp_done
                                                        : pmcraid_request_sense;

        memset(ioarcb->cdb, 0, PMCRAID_MAX_CDB_LEN);
        ioarcb->request_flags0 = SYNC_OVERRIDE;
        ioarcb->request_type = REQ_TYPE_IOACMD;
        ioarcb->cdb[0] = PMCRAID_CANCEL_ALL_REQUESTS;

        if (RES_IS_GSCSI(res->cfg_entry))
                ioarcb->cdb[1] = PMCRAID_SYNC_COMPLETE_AFTER_CANCEL;

        ioarcb->ioadl_bus_addr = 0;
        ioarcb->ioadl_length = 0;
        ioarcb->data_transfer_length = 0;
        ioarcb->ioarcb_bus_addr &= cpu_to_le64((~0x1FULL));

        /* writing to IOARRIN must be protected by host_lock, as mid-layer
         * schedule queuecommand while we are doing this
         */
        pmcraid_send_cmd(cmd, cmd_done,
                         PMCRAID_REQUEST_SENSE_TIMEOUT,
                         pmcraid_timeout_handler);
}

/**
 * pmcraid_frame_auto_sense: frame fixed format sense information
 *
 * @cmd: pointer to failing command block
 *
 * Return value
 *  none
 */
static void pmcraid_frame_auto_sense(struct pmcraid_cmd *cmd)
{
        u8 *sense_buf = cmd->scsi_cmd->sense_buffer;
        struct pmcraid_resource_entry *res = cmd->scsi_cmd->device->hostdata;
        struct pmcraid_ioasa *ioasa = &cmd->ioa_cb->ioasa;
        u32 ioasc = le32_to_cpu(ioasa->ioasc);
        u32 failing_lba = 0;

        memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);
        cmd->scsi_cmd->result = SAM_STAT_CHECK_CONDITION;

        if (RES_IS_VSET(res->cfg_entry) &&
            ioasc == PMCRAID_IOASC_ME_READ_ERROR_NO_REALLOC &&
            ioasa->u.vset.failing_lba_hi != 0) {

                sense_buf[0] = 0x72;
                sense_buf[1] = PMCRAID_IOASC_SENSE_KEY(ioasc);
                sense_buf[2] = PMCRAID_IOASC_SENSE_CODE(ioasc);
                sense_buf[3] = PMCRAID_IOASC_SENSE_QUAL(ioasc);

                sense_buf[7] = 12;
                sense_buf[8] = 0;
                sense_buf[9] = 0x0A;
                sense_buf[10] = 0x80;

                failing_lba = le32_to_cpu(ioasa->u.vset.failing_lba_hi);

                sense_buf[12] = (failing_lba & 0xff000000) >> 24;
                sense_buf[13] = (failing_lba & 0x00ff0000) >> 16;
                sense_buf[14] = (failing_lba & 0x0000ff00) >> 8;
                sense_buf[15] = failing_lba & 0x000000ff;

                failing_lba = le32_to_cpu(ioasa->u.vset.failing_lba_lo);

                sense_buf[16] = (failing_lba & 0xff000000) >> 24;
                sense_buf[17] = (failing_lba & 0x00ff0000) >> 16;
                sense_buf[18] = (failing_lba & 0x0000ff00) >> 8;
                sense_buf[19] = failing_lba & 0x000000ff;
        } else {
                sense_buf[0] = 0x70;
                sense_buf[2] = PMCRAID_IOASC_SENSE_KEY(ioasc);
                sense_buf[12] = PMCRAID_IOASC_SENSE_CODE(ioasc);
                sense_buf[13] = PMCRAID_IOASC_SENSE_QUAL(ioasc);

                if (ioasc == PMCRAID_IOASC_ME_READ_ERROR_NO_REALLOC) {
                        if (RES_IS_VSET(res->cfg_entry))
                                failing_lba =
                                        le32_to_cpu(ioasa->u.
                                                 vset.failing_lba_lo);
                        sense_buf[0] |= 0x80;
                        sense_buf[3] = (failing_lba >> 24) & 0xff;
                        sense_buf[4] = (failing_lba >> 16) & 0xff;
                        sense_buf[5] = (failing_lba >> 8) & 0xff;
                        sense_buf[6] = failing_lba & 0xff;
                }

                sense_buf[7] = 6; /* additional length */
        }
}

/**
 * pmcraid_error_handler - Error response handlers for a SCSI op
 * @cmd: pointer to pmcraid_cmd that has failed
 *
 * This function determines whether or not to initiate ERP on the affected
 * device. This is called from a tasklet, which doesn't hold any locks.
 *
 * Return value:
 *       0 it caller can complete the request, otherwise 1 where in error
 *       handler itself completes the request and returns the command block
 *       back to free-pool
 */
static int pmcraid_error_handler(struct pmcraid_cmd *cmd)
{
        struct scsi_cmnd *scsi_cmd = cmd->scsi_cmd;
        struct pmcraid_resource_entry *res = scsi_cmd->device->hostdata;
        struct pmcraid_instance *pinstance = cmd->drv_inst;
        struct pmcraid_ioasa *ioasa = &cmd->ioa_cb->ioasa;
        u32 ioasc = le32_to_cpu(ioasa->ioasc);
        u32 masked_ioasc = ioasc & PMCRAID_IOASC_SENSE_MASK;
        u32 sense_copied = 0;

        if (!res) {
                pmcraid_info("resource pointer is NULL\n");
                return 0;
        }

        /* If this was a SCSI read/write command keep count of errors */
        if (SCSI_CMD_TYPE(scsi_cmd->cmnd[0]) == SCSI_READ_CMD)
                atomic_inc(&res->read_failures);
        else if (SCSI_CMD_TYPE(scsi_cmd->cmnd[0]) == SCSI_WRITE_CMD)
                atomic_inc(&res->write_failures);

        if (!RES_IS_GSCSI(res->cfg_entry) &&
                masked_ioasc != PMCRAID_IOASC_HW_DEVICE_BUS_STATUS_ERROR) {
                pmcraid_frame_auto_sense(cmd);
        }

        /* Log IOASC/IOASA information based on user settings */
        pmcraid_ioasc_logger(ioasc, cmd);

        switch (masked_ioasc) {

        case PMCRAID_IOASC_AC_TERMINATED_BY_HOST:
                scsi_cmd->result |= (DID_ABORT << 16);
                break;

        case PMCRAID_IOASC_IR_INVALID_RESOURCE_HANDLE:
        case PMCRAID_IOASC_HW_CANNOT_COMMUNICATE:
                scsi_cmd->result |= (DID_NO_CONNECT << 16);
                break;

        case PMCRAID_IOASC_NR_SYNC_REQUIRED:
                res->sync_reqd = 1;
                scsi_cmd->result |= (DID_IMM_RETRY << 16);
                break;

        case PMCRAID_IOASC_ME_READ_ERROR_NO_REALLOC:
                scsi_cmd->result |= (DID_PASSTHROUGH << 16);
                break;

        case PMCRAID_IOASC_UA_BUS_WAS_RESET:
        case PMCRAID_IOASC_UA_BUS_WAS_RESET_BY_OTHER:
                if (!res->reset_progress)
                        scsi_report_bus_reset(pinstance->host,
                                              scsi_cmd->device->channel);
                scsi_cmd->result |= (DID_ERROR << 16);
                break;

        case PMCRAID_IOASC_HW_DEVICE_BUS_STATUS_ERROR:
                scsi_cmd->result |= PMCRAID_IOASC_SENSE_STATUS(ioasc);
                res->sync_reqd = 1;

                /* if check_condition is not active return with error otherwise
                 * get/frame the sense buffer
                 */
                if (PMCRAID_IOASC_SENSE_STATUS(ioasc) !=
                    SAM_STAT_CHECK_CONDITION &&
                    PMCRAID_IOASC_SENSE_STATUS(ioasc) != SAM_STAT_ACA_ACTIVE)
                        return 0;

                /* If we have auto sense data as part of IOASA pass it to
                 * mid-layer
                 */
                if (ioasa->auto_sense_length != 0) {
                        short sense_len = le16_to_cpu(ioasa->auto_sense_length);
                        int data_size = min_t(u16, sense_len,
                                              SCSI_SENSE_BUFFERSIZE);

                        memcpy(scsi_cmd->sense_buffer,
                               ioasa->sense_data,
                               data_size);
                        sense_copied = 1;
                }

                if (RES_IS_GSCSI(res->cfg_entry))
                        pmcraid_cancel_all(cmd, sense_copied);
                else if (sense_copied)
                        pmcraid_erp_done(cmd);
                else
                        pmcraid_request_sense(cmd);

                return 1;

        case PMCRAID_IOASC_NR_INIT_CMD_REQUIRED:
                break;

        default:
                if (PMCRAID_IOASC_SENSE_KEY(ioasc) > RECOVERED_ERROR)
                        scsi_cmd->result |= (DID_ERROR << 16);
                break;
        }
        return 0;
}

/**
 * pmcraid_reset_device - device reset handler functions
 *
 * @scsi_cmd: scsi command struct
 * @modifier: reset modifier indicating the reset sequence to be performed
 *
 * This function issues a device reset to the affected device.
 * A LUN reset will be sent to the device first. If that does
 * not work, a target reset will be sent.
 *
 * Return value:
 *      SUCCESS / FAILED
 */
static int pmcraid_reset_device(
        struct scsi_cmnd *scsi_cmd,
        unsigned long timeout,
        u8 modifier
)
{
        struct pmcraid_cmd *cmd;
        struct pmcraid_instance *pinstance;
        struct pmcraid_resource_entry *res;
        struct pmcraid_ioarcb *ioarcb;
        unsigned long lock_flags;
        u32 ioasc;

        pinstance =
                (struct pmcraid_instance *)scsi_cmd->device->host->hostdata;
        res = scsi_cmd->device->hostdata;

        if (!res) {
                sdev_printk(KERN_ERR, scsi_cmd->device,
                            "reset_device: NULL resource pointer\n");
                return FAILED;
        }

        /* If adapter is currently going through reset/reload, return failed.
         * This will force the mid-layer to call _eh_bus/host reset, which
         * will then go to sleep and wait for the reset to complete
         */
        spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
        if (pinstance->ioa_reset_in_progress ||
            pinstance->ioa_state == IOA_STATE_DEAD) {
                spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
                return FAILED;
        }

        res->reset_progress = 1;
        pmcraid_info("Resetting %s resource with addr %x\n",
                     ((modifier & RESET_DEVICE_LUN) ? "LUN" :
                     ((modifier & RESET_DEVICE_TARGET) ? "TARGET" : "BUS")),
                     le32_to_cpu(res->cfg_entry.resource_address));

        /* get a free cmd block */
        cmd = pmcraid_get_free_cmd(pinstance);

        if (cmd == NULL) {
                spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);
                pmcraid_err("%s: no cmd blocks are available\n", __func__);
                return FAILED;
        }

        ioarcb = &cmd->ioa_cb->ioarcb;
        ioarcb->resource_handle = res->cfg_entry.resource_handle;
        ioarcb->request_type = REQ_TYPE_IOACMD;
        ioarcb->cdb[0] = PMCRAID_RESET_DEVICE;

        /* Initialize reset modifier bits */
        if (modifier)
                modifier = ENABLE_RESET_MODIFIER | modifier;

        ioarcb->cdb[1] = modifier;

        init_completion(&cmd->wait_for_completion);
        cmd->completion_req = 1;

        pmcraid_info("cmd(CDB[0] = %x) for %x with index = %d\n",
                     cmd->ioa_cb->ioarcb.cdb[0],
                     le32_to_cpu(cmd->ioa_cb->ioarcb.resource_handle),
                     le32_to_cpu(cmd->ioa_cb->ioarcb.response_handle) >> 2);

        pmcraid_send_cmd(cmd,
                         pmcraid_internal_done,
                         timeout,
                         pmcraid_timeout_handler);

        spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);

        /* RESET_DEVICE command completes after all pending IOARCBs are
         * completed. Once this command is completed, pmcraind_internal_done
         * will wake up the 'completion' queue.
         */
        wait_for_completion(&cmd->wait_for_completion);

        /* complete the command here itself and return the command block
         * to free list
         */
        pmcraid_return_cmd(cmd);
        res->reset_progress = 0;
        ioasc = le32_to_cpu(cmd->ioa_cb->ioasa.ioasc);

        /* set the return value based on the returned ioasc */
        return PMCRAID_IOASC_SENSE_KEY(ioasc) ? FAILED : SUCCESS;
}

/**
 * _pmcraid_io_done - helper for pmcraid_io_done function
 *
 * @cmd: pointer to pmcraid command struct
 * @reslen: residual data length to be set in the ioasa
 * @ioasc: ioasc either returned by IOA or set by driver itself.
 *
 * This function is invoked by pmcraid_io_done to complete mid-layer
 * scsi ops.
 *
 * Return value:
 *        0 if caller is required to return it to free_pool. Returns 1 if
 *        caller need not worry about freeing command block as error handler
 *        will take care of that.
 */

static int _pmcraid_io_done(struct pmcraid_cmd *cmd, int reslen, int ioasc)
{
        struct scsi_cmnd *scsi_cmd = cmd->scsi_cmd;
        int rc = 0;

        scsi_set_resid(scsi_cmd, reslen);

        pmcraid_info("response(%d) CDB[0] = %x ioasc:result: %x:%x\n",
                le32_to_cpu(cmd->ioa_cb->ioarcb.response_handle) >> 2,
                cmd->ioa_cb->ioarcb.cdb[0],
                ioasc, scsi_cmd->result);

        if (PMCRAID_IOASC_SENSE_KEY(ioasc) != 0)
                rc = pmcraid_error_handler(cmd);

        if (rc == 0) {
                scsi_dma_unmap(scsi_cmd);
                scsi_cmd->scsi_done(scsi_cmd);
        }

        return rc;
}

/**
 * pmcraid_io_done - SCSI completion function
 *
 * @cmd: pointer to pmcraid command struct
 *
 * This function is invoked by tasklet/mid-layer error handler to completing
 * the SCSI ops sent from mid-layer.
 *
 * Return value
 *        none
 */

static void pmcraid_io_done(struct pmcraid_cmd *cmd)
{
        u32 ioasc = le32_to_cpu(cmd->ioa_cb->ioasa.ioasc);
        u32 reslen = le32_to_cpu(cmd->ioa_cb->ioasa.residual_data_length);

        if (_pmcraid_io_done(cmd, reslen, ioasc) == 0)
                pmcraid_return_cmd(cmd);
}

/**
 * pmcraid_abort_cmd - Aborts a single IOARCB already submitted to IOA
 *
 * @cmd: command block of the command to be aborted
 *
 * Return Value:
 *       returns pointer to command structure used as cancelling cmd
 */
static struct pmcraid_cmd *pmcraid_abort_cmd(struct pmcraid_cmd *cmd)
{
        struct pmcraid_cmd *cancel_cmd;
        struct pmcraid_instance *pinstance;
        struct pmcraid_resource_entry *res;

        pinstance = (struct pmcraid_instance *)cmd->drv_inst;
        res = cmd->scsi_cmd->device->hostdata;

        cancel_cmd = pmcraid_get_free_cmd(pinstance);

        if (cancel_cmd == NULL) {
                pmcraid_err("%s: no cmd blocks are available\n", __func__);
                return NULL;
        }

        pmcraid_prepare_cancel_cmd(cancel_cmd, cmd);

        pmcraid_info("aborting command CDB[0]= %x with index = %d\n",
                cmd->ioa_cb->ioarcb.cdb[0],
                le32_to_cpu(cmd->ioa_cb->ioarcb.response_handle) >> 2);

        init_completion(&cancel_cmd->wait_for_completion);
        cancel_cmd->completion_req = 1;

        pmcraid_info("command (%d) CDB[0] = %x for %x\n",
                le32_to_cpu(cancel_cmd->ioa_cb->ioarcb.response_handle) >> 2,
                cancel_cmd->ioa_cb->ioarcb.cdb[0],
                le32_to_cpu(cancel_cmd->ioa_cb->ioarcb.resource_handle));

        pmcraid_send_cmd(cancel_cmd,
                         pmcraid_internal_done,
                         PMCRAID_INTERNAL_TIMEOUT,
                         pmcraid_timeout_handler);
        return cancel_cmd;
}

/**
 * pmcraid_abort_complete - Waits for ABORT TASK completion
 *
 * @cancel_cmd: command block use as cancelling command
 *
 * Return Value:
 *       returns SUCCESS if ABORT TASK has good completion
 *       otherwise FAILED
 */
static int pmcraid_abort_complete(struct pmcraid_cmd *cancel_cmd)
{
        struct pmcraid_resource_entry *res;
        u32 ioasc;

        wait_for_completion(&cancel_cmd->wait_for_completion);
        res = cancel_cmd->res;
        cancel_cmd->res = NULL;
        ioasc = le32_to_cpu(cancel_cmd->ioa_cb->ioasa.ioasc);

        /* If the abort task is not timed out we will get a Good completion
         * as sense_key, otherwise we may get one the following responses
         * due to subsequent bus reset or device reset. In case IOASC is
         * NR_SYNC_REQUIRED, set sync_reqd flag for the corresponding resource
         */
        if (ioasc == PMCRAID_IOASC_UA_BUS_WAS_RESET ||
            ioasc == PMCRAID_IOASC_NR_SYNC_REQUIRED) {
                if (ioasc == PMCRAID_IOASC_NR_SYNC_REQUIRED)
                        res->sync_reqd = 1;
                ioasc = 0;
        }

        /* complete the command here itself */
        pmcraid_return_cmd(cancel_cmd);
        return PMCRAID_IOASC_SENSE_KEY(ioasc) ? FAILED : SUCCESS;
}

/**
 * pmcraid_eh_abort_handler - entry point for aborting a single task on errors
 *
 * @scsi_cmd:   scsi command struct given by mid-layer. When this is called
 *              mid-layer ensures that no other commands are queued. This
 *              never gets called under interrupt, but a separate eh thread.
 *
 * Return value:
 *       SUCCESS / FAILED
 */
static int pmcraid_eh_abort_handler(struct scsi_cmnd *scsi_cmd)
{
        struct pmcraid_instance *pinstance;
        struct pmcraid_cmd *cmd;
        struct pmcraid_resource_entry *res;
        unsigned long host_lock_flags;
        unsigned long pending_lock_flags;
        struct pmcraid_cmd *cancel_cmd = NULL;
        int cmd_found = 0;
        int rc = FAILED;

        pinstance =
                (struct pmcraid_instance *)scsi_cmd->device->host->hostdata;

        scmd_printk(KERN_INFO, scsi_cmd,
                    "I/O command timed out, aborting it.\n");

        res = scsi_cmd->device->hostdata;

        if (res == NULL)
                return rc;

        /* If we are currently going through reset/reload, return failed.
         * This will force the mid-layer to eventually call
         * pmcraid_eh_host_reset which will then go to sleep and wait for the
         * reset to complete
         */
        spin_lock_irqsave(pinstance->host->host_lock, host_lock_flags);

        if (pinstance->ioa_reset_in_progress ||
            pinstance->ioa_state == IOA_STATE_DEAD) {
                spin_unlock_irqrestore(pinstance->host->host_lock,
                                       host_lock_flags);
                return rc;
        }

        /* loop over pending cmd list to find cmd corresponding to this
         * scsi_cmd. Note that this command might not have been completed
         * already. locking: all pending commands are protected with
         * pending_pool_lock.
         */
        spin_lock_irqsave(&pinstance->pending_pool_lock, pending_lock_flags);
        list_for_each_entry(cmd, &pinstance->pending_cmd_pool, free_list) {

                if (cmd->scsi_cmd == scsi_cmd) {
                        cmd_found = 1;
                        break;
                }
        }

        spin_unlock_irqrestore(&pinstance->pending_pool_lock,
                                pending_lock_flags);

        /* If the command to be aborted was given to IOA and still pending with
         * it, send ABORT_TASK to abort this and wait for its completion
         */
        if (cmd_found)
                cancel_cmd = pmcraid_abort_cmd(cmd);

        spin_unlock_irqrestore(pinstance->host->host_lock,
                               host_lock_flags);

        if (cancel_cmd) {
                cancel_cmd->res = cmd->scsi_cmd->device->hostdata;
                rc = pmcraid_abort_complete(cancel_cmd);
        }

        return cmd_found ? rc : SUCCESS;
}

/**
 * pmcraid_eh_xxxx_reset_handler - bus/target/device reset handler callbacks
 *
 * @scmd: pointer to scsi_cmd that was sent to the resource to be reset.
 *
 * All these routines invokve pmcraid_reset_device with appropriate parameters.
 * Since these are called from mid-layer EH thread, no other IO will be queued
 * to the resource being reset. However, control path (IOCTL) may be active so
 * it is necessary to synchronize IOARRIN writes which pmcraid_reset_device
 * takes care by locking/unlocking host_lock.
 *
 * Return value
 *      SUCCESS or FAILED
 */
static int pmcraid_eh_device_reset_handler(struct scsi_cmnd *scmd)
{
        scmd_printk(KERN_INFO, scmd,
                    "resetting device due to an I/O command timeout.\n");
        return pmcraid_reset_device(scmd,
                                    PMCRAID_INTERNAL_TIMEOUT,
                                    RESET_DEVICE_LUN);
}

static int pmcraid_eh_bus_reset_handler(struct scsi_cmnd *scmd)
{
        scmd_printk(KERN_INFO, scmd,
                    "Doing bus reset due to an I/O command timeout.\n");
        return pmcraid_reset_device(scmd,
                                    PMCRAID_RESET_BUS_TIMEOUT,
                                    RESET_DEVICE_BUS);
}

static int pmcraid_eh_target_reset_handler(struct scsi_cmnd *scmd)
{
        scmd_printk(KERN_INFO, scmd,
                    "Doing target reset due to an I/O command timeout.\n");
        return pmcraid_reset_device(scmd,
                                    PMCRAID_INTERNAL_TIMEOUT,
                                    RESET_DEVICE_TARGET);
}

/**
 * pmcraid_eh_host_reset_handler - adapter reset handler callback
 *
 * @scmd: pointer to scsi_cmd that was sent to a resource of adapter
 *
 * Initiates adapter reset to bring it up to operational state
 *
 * Return value
 *      SUCCESS or FAILED
 */
static int pmcraid_eh_host_reset_handler(struct scsi_cmnd *scmd)
{
        unsigned long interval = 10000; /* 10 seconds interval */
        int waits = jiffies_to_msecs(PMCRAID_RESET_HOST_TIMEOUT) / interval;
        struct pmcraid_instance *pinstance =
                (struct pmcraid_instance *)(scmd->device->host->hostdata);


        /* wait for an additional 150 seconds just in case firmware could come
         * up and if it could complete all the pending commands excluding the
         * two HCAM (CCN and LDN).
         */
        while (waits--) {
                if (atomic_read(&pinstance->outstanding_cmds) <=
                    PMCRAID_MAX_HCAM_CMD)
                        return SUCCESS;
                msleep(interval);
        }

        dev_err(&pinstance->pdev->dev,
                "Adapter being reset due to an I/O command timeout.\n");
        return pmcraid_reset_bringup(pinstance) == 0 ? SUCCESS : FAILED;
}

/**
 * pmcraid_init_ioadls - initializes IOADL related fields in IOARCB
 * @cmd: pmcraid command struct
 * @sgcount: count of scatter-gather elements
 *
 * Return value
 *   returns pointer pmcraid_ioadl_desc, initialized to point to internal
 *   or external IOADLs
 */
static struct pmcraid_ioadl_desc *
pmcraid_init_ioadls(struct pmcraid_cmd *cmd, int sgcount)
{
        struct pmcraid_ioadl_desc *ioadl;
        struct pmcraid_ioarcb *ioarcb = &cmd->ioa_cb->ioarcb;
        int ioadl_count = 0;

        if (ioarcb->add_cmd_param_length)
                ioadl_count = DIV_ROUND_UP(le16_to_cpu(ioarcb->add_cmd_param_length), 16);
        ioarcb->ioadl_length = cpu_to_le32(sizeof(struct pmcraid_ioadl_desc) * sgcount);

        if ((sgcount + ioadl_count) > (ARRAY_SIZE(ioarcb->add_data.u.ioadl))) {
                /* external ioadls start at offset 0x80 from control_block
                 * structure, re-using 24 out of 27 ioadls part of IOARCB.
                 * It is necessary to indicate to firmware that driver is
                 * using ioadls to be treated as external to IOARCB.
                 */
                ioarcb->ioarcb_bus_addr &= cpu_to_le64(~(0x1FULL));
                ioarcb->ioadl_bus_addr =
                        cpu_to_le64((cmd->ioa_cb_bus_addr) +
                                offsetof(struct pmcraid_ioarcb,
                                        add_data.u.ioadl[3]));
                ioadl = &ioarcb->add_data.u.ioadl[3];
        } else {
                ioarcb->ioadl_bus_addr =
                        cpu_to_le64((cmd->ioa_cb_bus_addr) +
                                offsetof(struct pmcraid_ioarcb,
                                        add_data.u.ioadl[ioadl_count]));

                ioadl = &ioarcb->add_data.u.ioadl[ioadl_count];
                ioarcb->ioarcb_bus_addr |=
                        cpu_to_le64(DIV_ROUND_CLOSEST(sgcount + ioadl_count, 8));
        }

        return ioadl;
}

/**
 * pmcraid_build_ioadl - Build a scatter/gather list and map the buffer
 * @pinstance: pointer to adapter instance structure
 * @cmd: pmcraid command struct
 *
 * This function is invoked by queuecommand entry point while sending a command
 * to firmware. This builds ioadl descriptors and sets up ioarcb fields.
 *
 * Return value:
 *      0 on success or -1 on failure
 */
static int pmcraid_build_ioadl(
        struct pmcraid_instance *pinstance,
        struct pmcraid_cmd *cmd
)
{
        int i, nseg;
        struct scatterlist *sglist;

        struct scsi_cmnd *scsi_cmd = cmd->scsi_cmd;
        struct pmcraid_ioarcb *ioarcb = &(cmd->ioa_cb->ioarcb);
        struct pmcraid_ioadl_desc *ioadl = ioarcb->add_data.u.ioadl;

        u32 length = scsi_bufflen(scsi_cmd);

        if (!length)
                return 0;

        nseg = scsi_dma_map(scsi_cmd);

        if (nseg < 0) {
                scmd_printk(KERN_ERR, scsi_cmd, "scsi_map_dma failed!\n");
                return -1;
        } else if (nseg > PMCRAID_MAX_IOADLS) {
                scsi_dma_unmap(scsi_cmd);
                scmd_printk(KERN_ERR, scsi_cmd,
                        "sg count is (%d) more than allowed!\n", nseg);
                return -1;
        }

        /* Initialize IOARCB data transfer length fields */
        if (scsi_cmd->sc_data_direction == DMA_TO_DEVICE)
                ioarcb->request_flags0 |= TRANSFER_DIR_WRITE;

        ioarcb->request_flags0 |= NO_LINK_DESCS;
        ioarcb->data_transfer_length = cpu_to_le32(length);
        ioadl = pmcraid_init_ioadls(cmd, nseg);

        /* Initialize IOADL descriptor addresses */
        scsi_for_each_sg(scsi_cmd, sglist, nseg, i) {
                ioadl[i].data_len = cpu_to_le32(sg_dma_len(sglist));
                ioadl[i].address = cpu_to_le64(sg_dma_address(sglist));
                ioadl[i].flags = 0;
        }
        /* setup last descriptor */
        ioadl[i - 1].flags = IOADL_FLAGS_LAST_DESC;

        return 0;
}

/**
 * pmcraid_free_sglist - Frees an allocated SG buffer list
 * @sglist: scatter/gather list pointer
 *
 * Free a DMA'able memory previously allocated with pmcraid_alloc_sglist
 *
 * Return value:
 *      none
 */
static void pmcraid_free_sglist(struct pmcraid_sglist *sglist)
{
        int i;

        for (i = 0; i < sglist->num_sg; i++)
                __free_pages(sg_page(&(sglist->scatterlist[i])),
                             sglist->order);

        kfree(sglist);
}

/**
 * pmcraid_alloc_sglist - Allocates memory for a SG list
 * @buflen: buffer length
 *
 * Allocates a DMA'able buffer in chunks and assembles a scatter/gather
 * list.
 *
 * Return value
 *      pointer to sglist / NULL on failure
 */
static struct pmcraid_sglist *pmcraid_alloc_sglist(int buflen)
{
        struct pmcraid_sglist *sglist;
        struct scatterlist *scatterlist;
        struct page *page;
        int num_elem, i, j;
        int sg_size;
        int order;
        int bsize_elem;

        sg_size = buflen / (PMCRAID_MAX_IOADLS - 1);
        order = (sg_size > 0) ? get_order(sg_size) : 0;
        bsize_elem = PAGE_SIZE * (1 << order);

        /* Determine the actual number of sg entries needed */
        if (buflen % bsize_elem)
                num_elem = (buflen / bsize_elem) + 1;
        else
                num_elem = buflen / bsize_elem;

        /* Allocate a scatter/gather list for the DMA */
        sglist = kzalloc(sizeof(struct pmcraid_sglist) +
                         (sizeof(struct scatterlist) * (num_elem - 1)),
                         GFP_KERNEL);

        if (sglist == NULL)
                return NULL;

        scatterlist = sglist->scatterlist;
        sg_init_table(scatterlist, num_elem);
        sglist->order = order;
        sglist->num_sg = num_elem;
        sg_size = buflen;

        for (i = 0; i < num_elem; i++) {
                page = alloc_pages(GFP_KERNEL|GFP_DMA|__GFP_ZERO, order);
                if (!page) {
                        for (j = i - 1; j >= 0; j--)
                                __free_pages(sg_page(&scatterlist[j]), order);
                        kfree(sglist);
                        return NULL;
                }

                sg_set_page(&scatterlist[i], page,
                        sg_size < bsize_elem ? sg_size : bsize_elem, 0);
                sg_size -= bsize_elem;
        }

        return sglist;
}

/**
 * pmcraid_copy_sglist - Copy user buffer to kernel buffer's SG list
 * @sglist: scatter/gather list pointer
 * @buffer: buffer pointer
 * @len: buffer length
 * @direction: data transfer direction
 *
 * Copy a user buffer into a buffer allocated by pmcraid_alloc_sglist
 *
 * Return value:
 * 0 on success / other on failure
 */
static int pmcraid_copy_sglist(
        struct pmcraid_sglist *sglist,
        void __user *buffer,
        u32 len,
        int direction
)
{
        struct scatterlist *scatterlist;
        void *kaddr;
        int bsize_elem;
        int i;
        int rc = 0;

        /* Determine the actual number of bytes per element */
        bsize_elem = PAGE_SIZE * (1 << sglist->order);

        scatterlist = sglist->scatterlist;

        for (i = 0; i < (len / bsize_elem); i++, buffer += bsize_elem) {
                struct page *page = sg_page(&scatterlist[i]);

                kaddr = kmap(page);
                if (direction == DMA_TO_DEVICE)
                        rc = copy_from_user(kaddr, buffer, bsize_elem);
                else
                        rc = copy_to_user(buffer, kaddr, bsize_elem);

                kunmap(page);

                if (rc) {
                        pmcraid_err("failed to copy user data into sg list\n");
                        return -EFAULT;
                }

                scatterlist[i].length = bsize_elem;
        }

        if (len % bsize_elem) {
                struct page *page = sg_page(&scatterlist[i]);

                kaddr = kmap(page);

                if (direction == DMA_TO_DEVICE)
                        rc = copy_from_user(kaddr, buffer, len % bsize_elem);
                else
                        rc = copy_to_user(buffer, kaddr, len % bsize_elem);

                kunmap(page);

                scatterlist[i].length = len % bsize_elem;
        }

        if (rc) {
                pmcraid_err("failed to copy user data into sg list\n");
                rc = -EFAULT;
        }

        return rc;
}

/**
 * pmcraid_queuecommand - Queue a mid-layer request
 * @scsi_cmd: scsi command struct
 * @done: done function
 *
 * This function queues a request generated by the mid-layer. Midlayer calls
 * this routine within host->lock. Some of the functions called by queuecommand
 * would use cmd block queue locks (free_pool_lock and pending_pool_lock)
 *
 * Return value:
 *        0 on success
 *        SCSI_MLQUEUE_DEVICE_BUSY if device is busy
 *        SCSI_MLQUEUE_HOST_BUSY if host is busy
 */
static int pmcraid_queuecommand_lck(
        struct scsi_cmnd *scsi_cmd,
        void (*done) (struct scsi_cmnd *)
)
{
        struct pmcraid_instance *pinstance;
        struct pmcraid_resource_entry *res;
        struct pmcraid_ioarcb *ioarcb;
        struct pmcraid_cmd *cmd;
        u32 fw_version;
        int rc = 0;

        pinstance =
                (struct pmcraid_instance *)scsi_cmd->device->host->hostdata;
        fw_version = be16_to_cpu(pinstance->inq_data->fw_version);
        scsi_cmd->scsi_done = done;
        res = scsi_cmd->device->hostdata;
        scsi_cmd->result = (DID_OK << 16);

        /* if adapter is marked as dead, set result to DID_NO_CONNECT complete
         * the command
         */
        if (pinstance->ioa_state == IOA_STATE_DEAD) {
                pmcraid_info("IOA is dead, but queuecommand is scheduled\n");
                scsi_cmd->result = (DID_NO_CONNECT << 16);
                scsi_cmd->scsi_done(scsi_cmd);
                return 0;
        }

        /* If IOA reset is in progress, can't queue the commands */
        if (pinstance->ioa_reset_in_progress)
                return SCSI_MLQUEUE_HOST_BUSY;

        /* Firmware doesn't support SYNCHRONIZE_CACHE command (0x35), complete
         * the command here itself with success return
         */
        if (scsi_cmd->cmnd[0] == SYNCHRONIZE_CACHE) {
                pmcraid_info("SYNC_CACHE(0x35), completing in driver itself\n");
                scsi_cmd->scsi_done(scsi_cmd);
                return 0;
        }

        /* initialize the command and IOARCB to be sent to IOA */
        cmd = pmcraid_get_free_cmd(pinstance);

        if (cmd == NULL) {
                pmcraid_err("free command block is not available\n");
                return SCSI_MLQUEUE_HOST_BUSY;
        }

        cmd->scsi_cmd = scsi_cmd;
        ioarcb = &(cmd->ioa_cb->ioarcb);
        memcpy(ioarcb->cdb, scsi_cmd->cmnd, scsi_cmd->cmd_len);
        ioarcb->resource_handle = res->cfg_entry.resource_handle;
        ioarcb->request_type = REQ_TYPE_SCSI;

        /* set hrrq number where the IOA should respond to. Note that all cmds
         * generated internally uses hrrq_id 0, exception to this is the cmd
         * block of scsi_cmd which is re-used (e.g. cancel/abort), which uses
         * hrrq_id assigned here in queuecommand
         */
        ioarcb->hrrq_id = atomic_add_return(1, &(pinstance->last_message_id)) %
                          pinstance->num_hrrq;
        cmd->cmd_done = pmcraid_io_done;

        if (RES_IS_GSCSI(res->cfg_entry) || RES_IS_VSET(res->cfg_entry)) {
                if (scsi_cmd->underflow == 0)
                        ioarcb->request_flags0 |= INHIBIT_UL_CHECK;

                if (res->sync_reqd) {
                        ioarcb->request_flags0 |= SYNC_COMPLETE;
                        res->sync_reqd = 0;
                }

                ioarcb->request_flags0 |= NO_LINK_DESCS;

                if (scsi_cmd->flags & SCMD_TAGGED)
                        ioarcb->request_flags1 |= TASK_TAG_SIMPLE;

                if (RES_IS_GSCSI(res->cfg_entry))
                        ioarcb->request_flags1 |= DELAY_AFTER_RESET;
        }

        rc = pmcraid_build_ioadl(pinstance, cmd);

        pmcraid_info("command (%d) CDB[0] = %x for %x:%x:%x:%x\n",
                     le32_to_cpu(ioarcb->response_handle) >> 2,
                     scsi_cmd->cmnd[0], pinstance->host->unique_id,
                     RES_IS_VSET(res->cfg_entry) ? PMCRAID_VSET_BUS_ID :
                        PMCRAID_PHYS_BUS_ID,
                     RES_IS_VSET(res->cfg_entry) ?
                        (fw_version <= PMCRAID_FW_VERSION_1 ?
                                res->cfg_entry.unique_flags1 :
                                le16_to_cpu(res->cfg_entry.array_id) & 0xFF) :
                        RES_TARGET(res->cfg_entry.resource_address),
                     RES_LUN(res->cfg_entry.resource_address));

        if (likely(rc == 0)) {
                _pmcraid_fire_command(cmd);
        } else {
                pmcraid_err("queuecommand could not build ioadl\n");
                pmcraid_return_cmd(cmd);
                rc = SCSI_MLQUEUE_HOST_BUSY;
        }

        return rc;
}

static DEF_SCSI_QCMD(pmcraid_queuecommand)

/**
 * pmcraid_open -char node "open" entry, allowed only users with admin access
 */
static int pmcraid_chr_open(struct inode *inode, struct file *filep)
{
        struct pmcraid_instance *pinstance;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        /* Populate adapter instance * pointer for use by ioctl */
        pinstance = container_of(inode->i_cdev, struct pmcraid_instance, cdev);
        filep->private_data = pinstance;

        return 0;
}

/**
 * pmcraid_fasync - Async notifier registration from applications
 *
 * This function adds the calling process to a driver global queue. When an
 * event occurs, SIGIO will be sent to all processes in this queue.
 */
static int pmcraid_chr_fasync(int fd, struct file *filep, int mode)
{
        struct pmcraid_instance *pinstance;
        int rc;

        pinstance = filep->private_data;
        mutex_lock(&pinstance->aen_queue_lock);
        rc = fasync_helper(fd, filep, mode, &pinstance->aen_queue);
        mutex_unlock(&pinstance->aen_queue_lock);

        return rc;
}


/**
 * pmcraid_build_passthrough_ioadls - builds SG elements for passthrough
 * commands sent over IOCTL interface
 *
 * @cmd       : pointer to struct pmcraid_cmd
 * @buflen    : length of the request buffer
 * @direction : data transfer direction
 *
 * Return value
 *  0 on success, non-zero error code on failure
 */
static int pmcraid_build_passthrough_ioadls(
        struct pmcraid_cmd *cmd,
        int buflen,
        int direction
)
{
        struct pmcraid_sglist *sglist = NULL;
        struct scatterlist *sg = NULL;
        struct pmcraid_ioarcb *ioarcb = &cmd->ioa_cb->ioarcb;
        struct pmcraid_ioadl_desc *ioadl;
        int i;

        sglist = pmcraid_alloc_sglist(buflen);

        if (!sglist) {
                pmcraid_err("can't allocate memory for passthrough SGls\n");
                return -ENOMEM;
        }

        sglist->num_dma_sg = pci_map_sg(cmd->drv_inst->pdev,
                                        sglist->scatterlist,
                                        sglist->num_sg, direction);

        if (!sglist->num_dma_sg || sglist->num_dma_sg > PMCRAID_MAX_IOADLS) {
                dev_err(&cmd->drv_inst->pdev->dev,
                        "Failed to map passthrough buffer!\n");
                pmcraid_free_sglist(sglist);
                return -EIO;
        }

        cmd->sglist = sglist;
        ioarcb->request_flags0 |= NO_LINK_DESCS;

        ioadl = pmcraid_init_ioadls(cmd, sglist->num_dma_sg);

        /* Initialize IOADL descriptor addresses */
        for_each_sg(sglist->scatterlist, sg, sglist->num_dma_sg, i) {
                ioadl[i].data_len = cpu_to_le32(sg_dma_len(sg));
                ioadl[i].address = cpu_to_le64(sg_dma_address(sg));
                ioadl[i].flags = 0;
        }

        /* setup the last descriptor */
        ioadl[i - 1].flags = IOADL_FLAGS_LAST_DESC;

        return 0;
}


/**
 * pmcraid_release_passthrough_ioadls - release passthrough ioadls
 *
 * @cmd: pointer to struct pmcraid_cmd for which ioadls were allocated
 * @buflen: size of the request buffer
 * @direction: data transfer direction
 *
 * Return value
 *  0 on success, non-zero error code on failure
 */
static void pmcraid_release_passthrough_ioadls(
        struct pmcraid_cmd *cmd,
        int buflen,
        int direction
)
{
        struct pmcraid_sglist *sglist = cmd->sglist;

        if (buflen > 0) {
                pci_unmap_sg(cmd->drv_inst->pdev,
                             sglist->scatterlist,
                             sglist->num_sg,
                             direction);
                pmcraid_free_sglist(sglist);
                cmd->sglist = NULL;
        }
}

/**
 * pmcraid_ioctl_passthrough - handling passthrough IOCTL commands
 *
 * @pinstance: pointer to adapter instance structure
 * @cmd: ioctl code
 * @arg: pointer to pmcraid_passthrough_buffer user buffer
 *
 * Return value
 *  0 on success, non-zero error code on failure
 */
static long pmcraid_ioctl_passthrough(
        struct pmcraid_instance *pinstance,
        unsigned int ioctl_cmd,
        unsigned int buflen,
        void __user *arg
)
{
        struct pmcraid_passthrough_ioctl_buffer *buffer;
        struct pmcraid_ioarcb *ioarcb;
        struct pmcraid_cmd *cmd;
        struct pmcraid_cmd *cancel_cmd;
        void __user *request_buffer;
        unsigned long request_offset;
        unsigned long lock_flags;
        void __user *ioasa;
        u32 ioasc;
        int request_size;
        int buffer_size;
        u8 access, direction;
        int rc = 0;

        /* If IOA reset is in progress, wait 10 secs for reset to complete */
        if (pinstance->ioa_reset_in_progress) {
                rc = wait_event_interruptible_timeout(
                                pinstance->reset_wait_q,
                                !pinstance->ioa_reset_in_progress,
                                msecs_to_jiffies(10000));

                if (!rc)
                        return -ETIMEDOUT;
                else if (rc < 0)
                        return -ERESTARTSYS;
        }

        /* If adapter is not in operational state, return error */
        if (pinstance->ioa_state != IOA_STATE_OPERATIONAL) {
                pmcraid_err("IOA is not operational\n");
                return -ENOTTY;
        }

        buffer_size = sizeof(struct pmcraid_passthrough_ioctl_buffer);
        buffer = kmalloc(buffer_size, GFP_KERNEL);

        if (!buffer) {
                pmcraid_err("no memory for passthrough buffer\n");
                return -ENOMEM;
        }

        request_offset =
            offsetof(struct pmcraid_passthrough_ioctl_buffer, request_buffer);

        request_buffer = arg + request_offset;

        rc = copy_from_user(buffer, arg,
                             sizeof(struct pmcraid_passthrough_ioctl_buffer));

        ioasa = arg + offsetof(struct pmcraid_passthrough_ioctl_buffer, ioasa);

        if (rc) {
                pmcraid_err("ioctl: can't copy passthrough buffer\n");
                rc = -EFAULT;
                goto out_free_buffer;
        }

        request_size = le32_to_cpu(buffer->ioarcb.data_transfer_length);

        if (buffer->ioarcb.request_flags0 & TRANSFER_DIR_WRITE) {
                access = VERIFY_READ;
                direction = DMA_TO_DEVICE;
        } else {
                access = VERIFY_WRITE;
                direction = DMA_FROM_DEVICE;
        }

        if (request_size < 0) {
                rc = -EINVAL;
                goto out_free_buffer;
        }

        /* check if we have any additional command parameters */
        if (le16_to_cpu(buffer->ioarcb.add_cmd_param_length)
             > PMCRAID_ADD_CMD_PARAM_LEN) {
                rc = -EINVAL;
                goto out_free_buffer;
        }

        cmd = pmcraid_get_free_cmd(pinstance);

        if (!cmd) {
                pmcraid_err("free command block is not available\n");
                rc = -ENOMEM;
                goto out_free_buffer;
        }

        cmd->scsi_cmd = NULL;
        ioarcb = &(cmd->ioa_cb->ioarcb);

        /* Copy the user-provided IOARCB stuff field by field */
        ioarcb->resource_handle = buffer->ioarcb.resource_handle;
        ioarcb->data_transfer_length = buffer->ioarcb.data_transfer_length;
        ioarcb->cmd_timeout = buffer->ioarcb.cmd_timeout;
        ioarcb->request_type = buffer->ioarcb.request_type;
        ioarcb->request_flags0 = buffer->ioarcb.request_flags0;
        ioarcb->request_flags1 = buffer->ioarcb.request_flags1;
        memcpy(ioarcb->cdb, buffer->ioarcb.cdb, PMCRAID_MAX_CDB_LEN);

        if (buffer->ioarcb.add_cmd_param_length) {
                ioarcb->add_cmd_param_length =
                        buffer->ioarcb.add_cmd_param_length;
                ioarcb->add_cmd_param_offset =
                        buffer->ioarcb.add_cmd_param_offset;
                memcpy(ioarcb->add_data.u.add_cmd_params,
                        buffer->ioarcb.add_data.u.add_cmd_params,
                        le16_to_cpu(buffer->ioarcb.add_cmd_param_length));
        }

        /* set hrrq number where the IOA should respond to. Note that all cmds
         * generated internally uses hrrq_id 0, exception to this is the cmd
         * block of scsi_cmd which is re-used (e.g. cancel/abort), which uses
         * hrrq_id assigned here in queuecommand
         */
        ioarcb->hrrq_id = atomic_add_return(1, &(pinstance->last_message_id)) %
                          pinstance->num_hrrq;

        if (request_size) {
                rc = pmcraid_build_passthrough_ioadls(cmd,
                                                      request_size,
                                                      direction);
                if (rc) {
                        pmcraid_err("couldn't build passthrough ioadls\n");
                        goto out_free_cmd;
                }
        }

        /* If data is being written into the device, copy the data from user
         * buffers
         */
        if (direction == DMA_TO_DEVICE && request_size > 0) {
                rc = pmcraid_copy_sglist(cmd->sglist,
                                         request_buffer,
                                         request_size,
                                         direction);
                if (rc) {
                        pmcraid_err("failed to copy user buffer\n");
                        goto out_free_sglist;
                }
        }

        /* passthrough ioctl is a blocking command so, put the user to sleep
         * until timeout. Note that a timeout value of 0 means, do timeout.
         */
        cmd->cmd_done = pmcraid_internal_done;
        init_completion(&cmd->wait_for_completion);
        cmd->completion_req = 1;

        pmcraid_info("command(%d) (CDB[0] = %x) for %x\n",
                     le32_to_cpu(cmd->ioa_cb->ioarcb.response_handle) >> 2,
                     cmd->ioa_cb->ioarcb.cdb[0],
                     le32_to_cpu(cmd->ioa_cb->ioarcb.resource_handle));

        spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
        _pmcraid_fire_command(cmd);
        spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);

        /* NOTE ! Remove the below line once abort_task is implemented
         * in firmware. This line disables ioctl command timeout handling logic
         * similar to IO command timeout handling, making ioctl commands to wait
         * until the command completion regardless of timeout value specified in
         * ioarcb
         */
        buffer->ioarcb.cmd_timeout = 0;

        /* If command timeout is specified put caller to wait till that time,
         * otherwise it would be blocking wait. If command gets timed out, it
         * will be aborted.
         */
        if (buffer->ioarcb.cmd_timeout == 0) {
                wait_for_completion(&cmd->wait_for_completion);
        } else if (!wait_for_completion_timeout(
                        &cmd->wait_for_completion,
                        msecs_to_jiffies(le16_to_cpu(buffer->ioarcb.cmd_timeout) * 1000))) {

                pmcraid_info("aborting cmd %d (CDB[0] = %x) due to timeout\n",
                        le32_to_cpu(cmd->ioa_cb->ioarcb.response_handle) >> 2,
                        cmd->ioa_cb->ioarcb.cdb[0]);

                spin_lock_irqsave(pinstance->host->host_lock, lock_flags);
                cancel_cmd = pmcraid_abort_cmd(cmd);
                spin_unlock_irqrestore(pinstance->host->host_lock, lock_flags);

                if (cancel_cmd) {
                        wait_for_completion(&cancel_cmd->wait_for_completion);
                        ioasc = le32_to_cpu(cancel_cmd->ioa_cb->ioasa.ioasc);
                        pmcraid_return_cmd(cancel_cmd);

                        /* if abort task couldn't find the command i.e it got
                         * completed prior to aborting, return good completion.
                         * if command got aborted successfully or there was IOA
                         * reset due to abort task itself getting timedout then
                         * return -ETIMEDOUT
                         */
                        if (ioasc == PMCRAID_IOASC_IOA_WAS_RESET ||
                            PMCRAID_IOASC_SENSE_KEY(ioasc) == 0x00) {
                                if (ioasc != PMCRAID_IOASC_GC_IOARCB_NOTFOUND)
                                        rc = -ETIMEDOUT;
                                goto out_handle_response;
                        }
                }

                /* no command block for abort task or abort task failed to abort
                 * the IOARCB, then wait for 150 more seconds and initiate reset
                 * sequence after timeout
                 */
                if (!wait_for_completion_timeout(
                        &cmd->wait_for_completion,
                        msecs_to_jiffies(150 * 1000))) {
                        pmcraid_reset_bringup(cmd->drv_inst);
                        rc = -ETIMEDOUT;
                }
        }

out_handle_response:
        /* copy entire IOASA buffer and return IOCTL success.
         * If copying IOASA to user-buffer fails, return
         * EFAULT
         */
        if (copy_to_user(ioasa, &cmd->ioa_cb->ioasa,
                sizeof(struct pmcraid_ioasa))) {
                pmcraid_err("failed to copy ioasa buffer to user\n");
                rc = -EFAULT;
        }

        /* If the data transfer was from device, copy the data onto user
         * buffers
         */
        else if (direction == DMA_FROM_DEVICE && request_size > 0) {
                rc = pmcraid_copy_sglist(cmd->sglist,
                                         request_buffer,
                                         request_size,
                                         direction);
                if (rc) {
                        pmcraid_err("failed to copy user buffer\n");
                        rc = -EFAULT;
                }
        }

out_free_sglist:
        pmcraid_release_passthrough_ioadls(cmd, request_size, direction);

out_free_cmd:
        pmcraid_return_cmd(cmd);

out_free_buffer:
        kfree(buffer);

        return rc;
}




/**
 * pmcraid_ioctl_driver - ioctl handler for commands handled by driver itself
 *
 * @pinstance: pointer to adapter instance structure
 * @cmd: ioctl command passed in
 * @buflen: length of user_buffer
 * @user_buffer: user buffer pointer
 *
 * Return Value
 *   0 in case of success, otherwise appropriate error code
 */
static long pmcraid_ioctl_driver(
        struct pmcraid_instance *pinstance,
        unsigned int cmd,
        unsigned int buflen,
        void __user *user_buffer
)
{
        int rc = -ENOSYS;

        switch (cmd) {
        case PMCRAID_IOCTL_RESET_ADAPTER:
                pmcraid_reset_bringup(pinstance);
                rc = 0;
                break;

        default:
                break;
        }

        return rc;
}

/**
 * pmcraid_check_ioctl_buffer - check for proper access to user buffer
 *
 * @cmd: ioctl command
 * @arg: user buffer
 * @hdr: pointer to kernel memory for pmcraid_ioctl_header
 *
 * Return Value
 *      negetive error code if there are access issues, otherwise zero.
 *      Upon success, returns ioctl header copied out of user buffer.
 */

static int pmcraid_check_ioctl_buffer(
        int cmd,
        void __user *arg,
        struct pmcraid_ioctl_header *hdr
)
{
        int rc;

        if (copy_from_user(hdr, arg, sizeof(struct pmcraid_ioctl_header))) {
                pmcraid_err("couldn't copy ioctl header from user buffer\n");
                return -EFAULT;
        }

        /* check for valid driver signature */
        rc = memcmp(hdr->signature,
                    PMCRAID_IOCTL_SIGNATURE,
                    sizeof(hdr->signature));
        if (rc) {
                pmcraid_err("signature verification failed\n");
                return -EINVAL;
        }

        return 0;
}

/**
 *  pmcraid_ioctl - char node ioctl entry point
 */
static long pmcraid_chr_ioctl(
        struct file *filep,
        unsigned int cmd,
        unsigned long arg
)
{
        struct pmcraid_instance *pinstance = NULL;
        struct pmcraid_ioctl_header *hdr = NULL;
        void __user *argp = (void __user *)arg;
        int retval = -ENOTTY;

        hdr = kmalloc(sizeof(struct pmcraid_ioctl_header), GFP_KERNEL);

        if (!hdr) {
                pmcraid_err("failed to allocate memory for ioctl header\n");
                return -ENOMEM;
        }

        retval = pmcraid_check_ioctl_buffer(cmd, argp, hdr);

        if (retval) {
                pmcraid_info("chr_ioctl: header check failed\n");
                kfree(hdr);
                return retval;
        }

        pinstance = filep->private_data;

        if (!pinstance) {
                pmcraid_info("adapter instance is not found\n");
                kfree(hdr);