/*
 *
 *              Linux MegaRAID driver for SAS based RAID controllers
 *
 * Copyright (c) 2003-2005  LSI Corporation.
 *
 *         This program is free software; you can redistribute it and/or
 *         modify it under the terms of the GNU General Public License
 *         as published by the Free Software Foundation; either version
 *         2 of the License, or (at your option) any later version.
 *
 * FILE         : megaraid_sas.c
 * Version     : v00.00.04.17.1-rc1
 *
 * Authors:
 *      (email-id : megaraidlinux@lsi.com)
 *      Sreenivas Bagalkote
 *      Sumant Patro
 *      Bo Yang
 *
 * List of supported controllers
 *
 * OEM  Product Name                    VID     DID     SSVID   SSID
 * ---  ------------                    ---     ---     ----    ----
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/list.h>
#include <linux/moduleparam.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/smp_lock.h>
#include <linux/uio.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <linux/fs.h>
#include <linux/compat.h>
#include <linux/blkdev.h>
#include <linux/mutex.h>
#include <linux/poll.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include "megaraid_sas.h"

/*
 * poll_mode_io:1- schedule complete completion from q cmd
 */
static unsigned int poll_mode_io;
module_param_named(poll_mode_io, poll_mode_io, int, 0);
MODULE_PARM_DESC(poll_mode_io,
        "Complete cmds from IO path, (default=0)");

MODULE_LICENSE("GPL");
MODULE_VERSION(MEGASAS_VERSION);
MODULE_AUTHOR("megaraidlinux@lsi.com");
MODULE_DESCRIPTION("LSI MegaRAID SAS Driver");

/*
 * PCI ID table for all supported controllers
 */
static struct pci_device_id megasas_pci_table[] = {

        {PCI_DEVICE(PCI_VENDOR_ID_LSI_LOGIC, PCI_DEVICE_ID_LSI_SAS1064R)},
        /* xscale IOP */
        {PCI_DEVICE(PCI_VENDOR_ID_LSI_LOGIC, PCI_DEVICE_ID_LSI_SAS1078R)},
        /* ppc IOP */
        {PCI_DEVICE(PCI_VENDOR_ID_LSI_LOGIC, PCI_DEVICE_ID_LSI_SAS1078DE)},
        /* ppc IOP */
        {PCI_DEVICE(PCI_VENDOR_ID_LSI_LOGIC, PCI_DEVICE_ID_LSI_SAS1078GEN2)},
        /* gen2*/
        {PCI_DEVICE(PCI_VENDOR_ID_LSI_LOGIC, PCI_DEVICE_ID_LSI_SAS0079GEN2)},
        /* gen2*/
        {PCI_DEVICE(PCI_VENDOR_ID_LSI_LOGIC, PCI_DEVICE_ID_LSI_SAS0073SKINNY)},
        /* skinny*/
        {PCI_DEVICE(PCI_VENDOR_ID_LSI_LOGIC, PCI_DEVICE_ID_LSI_SAS0071SKINNY)},
        /* skinny*/
        {PCI_DEVICE(PCI_VENDOR_ID_LSI_LOGIC, PCI_DEVICE_ID_LSI_VERDE_ZCR)},
        /* xscale IOP, vega */
        {PCI_DEVICE(PCI_VENDOR_ID_DELL, PCI_DEVICE_ID_DELL_PERC5)},
        /* xscale IOP */
        {}
};

MODULE_DEVICE_TABLE(pci, megasas_pci_table);

static int megasas_mgmt_majorno;
static struct megasas_mgmt_info megasas_mgmt_info;
static struct fasync_struct *megasas_async_queue;
static DEFINE_MUTEX(megasas_async_queue_mutex);

static int megasas_poll_wait_aen;
static DECLARE_WAIT_QUEUE_HEAD(megasas_poll_wait);
static u32 support_poll_for_event;
static u32 megasas_dbg_lvl;

/* define lock for aen poll */
spinlock_t poll_aen_lock;

static void
megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd,
                     u8 alt_status);

/**
 * megasas_get_cmd -    Get a command from the free pool
 * @instance:           Adapter soft state
 *
 * Returns a free command from the pool
 */
static struct megasas_cmd *megasas_get_cmd(struct megasas_instance
                                                  *instance)
{
        unsigned long flags;
        struct megasas_cmd *cmd = NULL;

        spin_lock_irqsave(&instance->cmd_pool_lock, flags);

        if (!list_empty(&instance->cmd_pool)) {
                cmd = list_entry((&instance->cmd_pool)->next,
                                 struct megasas_cmd, list);
                list_del_init(&cmd->list);
        } else {
                printk(KERN_ERR "megasas: Command pool empty!\n");
        }

        spin_unlock_irqrestore(&instance->cmd_pool_lock, flags);
        return cmd;
}

/**
 * megasas_return_cmd - Return a cmd to free command pool
 * @instance:           Adapter soft state
 * @cmd:                Command packet to be returned to free command pool
 */
static inline void
megasas_return_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd)
{
        unsigned long flags;

        spin_lock_irqsave(&instance->cmd_pool_lock, flags);

        cmd->scmd = NULL;
        list_add_tail(&cmd->list, &instance->cmd_pool);

        spin_unlock_irqrestore(&instance->cmd_pool_lock, flags);
}


/**
*       The following functions are defined for xscale 
*       (deviceid : 1064R, PERC5) controllers
*/

/**
 * megasas_enable_intr_xscale - Enables interrupts
 * @regs:                       MFI register set
 */
static inline void
megasas_enable_intr_xscale(struct megasas_register_set __iomem * regs)
{
        writel(1, &(regs)->outbound_intr_mask);

        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_mask);
}

/**
 * megasas_disable_intr_xscale -Disables interrupt
 * @regs:                       MFI register set
 */
static inline void
megasas_disable_intr_xscale(struct megasas_register_set __iomem * regs)
{
        u32 mask = 0x1f;
        writel(mask, &regs->outbound_intr_mask);
        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_mask);
}

/**
 * megasas_read_fw_status_reg_xscale - returns the current FW status value
 * @regs:                       MFI register set
 */
static u32
megasas_read_fw_status_reg_xscale(struct megasas_register_set __iomem * regs)
{
        return readl(&(regs)->outbound_msg_0);
}
/**
 * megasas_clear_interrupt_xscale -     Check & clear interrupt
 * @regs:                               MFI register set
 */
static int 
megasas_clear_intr_xscale(struct megasas_register_set __iomem * regs)
{
        u32 status;
        /*
         * Check if it is our interrupt
         */
        status = readl(&regs->outbound_intr_status);

        if (!(status & MFI_OB_INTR_STATUS_MASK)) {
                return 1;
        }

        /*
         * Clear the interrupt by writing back the same value
         */
        writel(status, &regs->outbound_intr_status);

        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_status);

        return 0;
}

/**
 * megasas_fire_cmd_xscale -    Sends command to the FW
 * @frame_phys_addr :           Physical address of cmd
 * @frame_count :               Number of frames for the command
 * @regs :                      MFI register set
 */
static inline void 
megasas_fire_cmd_xscale(struct megasas_instance *instance,
                dma_addr_t frame_phys_addr,
                u32 frame_count,
                struct megasas_register_set __iomem *regs)
{
        writel((frame_phys_addr >> 3)|(frame_count),
               &(regs)->inbound_queue_port);
}

static struct megasas_instance_template megasas_instance_template_xscale = {

        .fire_cmd = megasas_fire_cmd_xscale,
        .enable_intr = megasas_enable_intr_xscale,
        .disable_intr = megasas_disable_intr_xscale,
        .clear_intr = megasas_clear_intr_xscale,
        .read_fw_status_reg = megasas_read_fw_status_reg_xscale,
};

/**
*       This is the end of set of functions & definitions specific 
*       to xscale (deviceid : 1064R, PERC5) controllers
*/

/**
*       The following functions are defined for ppc (deviceid : 0x60) 
*       controllers
*/

/**
 * megasas_enable_intr_ppc -    Enables interrupts
 * @regs:                       MFI register set
 */
static inline void
megasas_enable_intr_ppc(struct megasas_register_set __iomem * regs)
{
        writel(0xFFFFFFFF, &(regs)->outbound_doorbell_clear);
    
        writel(~0x80000004, &(regs)->outbound_intr_mask);

        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_mask);
}

/**
 * megasas_disable_intr_ppc -   Disable interrupt
 * @regs:                       MFI register set
 */
static inline void
megasas_disable_intr_ppc(struct megasas_register_set __iomem * regs)
{
        u32 mask = 0xFFFFFFFF;
        writel(mask, &regs->outbound_intr_mask);
        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_mask);
}

/**
 * megasas_read_fw_status_reg_ppc - returns the current FW status value
 * @regs:                       MFI register set
 */
static u32
megasas_read_fw_status_reg_ppc(struct megasas_register_set __iomem * regs)
{
        return readl(&(regs)->outbound_scratch_pad);
}

/**
 * megasas_clear_interrupt_ppc -        Check & clear interrupt
 * @regs:                               MFI register set
 */
static int 
megasas_clear_intr_ppc(struct megasas_register_set __iomem * regs)
{
        u32 status;
        /*
         * Check if it is our interrupt
         */
        status = readl(&regs->outbound_intr_status);

        if (!(status & MFI_REPLY_1078_MESSAGE_INTERRUPT)) {
                return 1;
        }

        /*
         * Clear the interrupt by writing back the same value
         */
        writel(status, &regs->outbound_doorbell_clear);

        /* Dummy readl to force pci flush */
        readl(&regs->outbound_doorbell_clear);

        return 0;
}
/**
 * megasas_fire_cmd_ppc -       Sends command to the FW
 * @frame_phys_addr :           Physical address of cmd
 * @frame_count :               Number of frames for the command
 * @regs :                      MFI register set
 */
static inline void 
megasas_fire_cmd_ppc(struct megasas_instance *instance,
                dma_addr_t frame_phys_addr,
                u32 frame_count,
                struct megasas_register_set __iomem *regs)
{
        writel((frame_phys_addr | (frame_count<<1))|1, 
                        &(regs)->inbound_queue_port);
}

static struct megasas_instance_template megasas_instance_template_ppc = {
        
        .fire_cmd = megasas_fire_cmd_ppc,
        .enable_intr = megasas_enable_intr_ppc,
        .disable_intr = megasas_disable_intr_ppc,
        .clear_intr = megasas_clear_intr_ppc,
        .read_fw_status_reg = megasas_read_fw_status_reg_ppc,
};

/**
 * megasas_enable_intr_skinny - Enables interrupts
 * @regs:                       MFI register set
 */
static inline void
megasas_enable_intr_skinny(struct megasas_register_set __iomem *regs)
{
        writel(0xFFFFFFFF, &(regs)->outbound_intr_mask);

        writel(~MFI_SKINNY_ENABLE_INTERRUPT_MASK, &(regs)->outbound_intr_mask);

        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_mask);
}

/**
 * megasas_disable_intr_skinny -        Disables interrupt
 * @regs:                       MFI register set
 */
static inline void
megasas_disable_intr_skinny(struct megasas_register_set __iomem *regs)
{
        u32 mask = 0xFFFFFFFF;
        writel(mask, &regs->outbound_intr_mask);
        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_mask);
}

/**
 * megasas_read_fw_status_reg_skinny - returns the current FW status value
 * @regs:                       MFI register set
 */
static u32
megasas_read_fw_status_reg_skinny(struct megasas_register_set __iomem *regs)
{
        return readl(&(regs)->outbound_scratch_pad);
}

/**
 * megasas_clear_interrupt_skinny -     Check & clear interrupt
 * @regs:                               MFI register set
 */
static int
megasas_clear_intr_skinny(struct megasas_register_set __iomem *regs)
{
        u32 status;
        /*
         * Check if it is our interrupt
         */
        status = readl(&regs->outbound_intr_status);

        if (!(status & MFI_SKINNY_ENABLE_INTERRUPT_MASK)) {
                return 1;
        }

        /*
         * Clear the interrupt by writing back the same value
         */
        writel(status, &regs->outbound_intr_status);

        /*
        * dummy read to flush PCI
        */
        readl(&regs->outbound_intr_status);

        return 0;
}

/**
 * megasas_fire_cmd_skinny -    Sends command to the FW
 * @frame_phys_addr :           Physical address of cmd
 * @frame_count :               Number of frames for the command
 * @regs :                      MFI register set
 */
static inline void
megasas_fire_cmd_skinny(struct megasas_instance *instance,
                        dma_addr_t frame_phys_addr,
                        u32 frame_count,
                        struct megasas_register_set __iomem *regs)
{
        unsigned long flags;
        spin_lock_irqsave(&instance->fire_lock, flags);
        writel(0, &(regs)->inbound_high_queue_port);
        writel((frame_phys_addr | (frame_count<<1))|1,
                &(regs)->inbound_low_queue_port);
        spin_unlock_irqrestore(&instance->fire_lock, flags);
}

static struct megasas_instance_template megasas_instance_template_skinny = {

        .fire_cmd = megasas_fire_cmd_skinny,
        .enable_intr = megasas_enable_intr_skinny,
        .disable_intr = megasas_disable_intr_skinny,
        .clear_intr = megasas_clear_intr_skinny,
        .read_fw_status_reg = megasas_read_fw_status_reg_skinny,
};


/**
*       The following functions are defined for gen2 (deviceid : 0x78 0x79)
*       controllers
*/

/**
 * megasas_enable_intr_gen2 -  Enables interrupts
 * @regs:                      MFI register set
 */
static inline void
megasas_enable_intr_gen2(struct megasas_register_set __iomem *regs)
{
        writel(0xFFFFFFFF, &(regs)->outbound_doorbell_clear);

        /* write ~0x00000005 (4 & 1) to the intr mask*/
        writel(~MFI_GEN2_ENABLE_INTERRUPT_MASK, &(regs)->outbound_intr_mask);

        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_mask);
}

/**
 * megasas_disable_intr_gen2 - Disables interrupt
 * @regs:                      MFI register set
 */
static inline void
megasas_disable_intr_gen2(struct megasas_register_set __iomem *regs)
{
        u32 mask = 0xFFFFFFFF;
        writel(mask, &regs->outbound_intr_mask);
        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_mask);
}

/**
 * megasas_read_fw_status_reg_gen2 - returns the current FW status value
 * @regs:                      MFI register set
 */
static u32
megasas_read_fw_status_reg_gen2(struct megasas_register_set __iomem *regs)
{
        return readl(&(regs)->outbound_scratch_pad);
}

/**
 * megasas_clear_interrupt_gen2 -      Check & clear interrupt
 * @regs:                              MFI register set
 */
static int
megasas_clear_intr_gen2(struct megasas_register_set __iomem *regs)
{
        u32 status;
        /*
         * Check if it is our interrupt
         */
        status = readl(&regs->outbound_intr_status);

        if (!(status & MFI_GEN2_ENABLE_INTERRUPT_MASK))
                return 1;

        /*
         * Clear the interrupt by writing back the same value
         */
        writel(status, &regs->outbound_doorbell_clear);

        /* Dummy readl to force pci flush */
        readl(&regs->outbound_intr_status);

        return 0;
}
/**
 * megasas_fire_cmd_gen2 -     Sends command to the FW
 * @frame_phys_addr :          Physical address of cmd
 * @frame_count :              Number of frames for the command
 * @regs :                     MFI register set
 */
static inline void
megasas_fire_cmd_gen2(struct megasas_instance *instance,
                        dma_addr_t frame_phys_addr,
                        u32 frame_count,
                        struct megasas_register_set __iomem *regs)
{
        writel((frame_phys_addr | (frame_count<<1))|1,
                        &(regs)->inbound_queue_port);
}

static struct megasas_instance_template megasas_instance_template_gen2 = {

        .fire_cmd = megasas_fire_cmd_gen2,
        .enable_intr = megasas_enable_intr_gen2,
        .disable_intr = megasas_disable_intr_gen2,
        .clear_intr = megasas_clear_intr_gen2,
        .read_fw_status_reg = megasas_read_fw_status_reg_gen2,
};

/**
*       This is the end of set of functions & definitions
*       specific to ppc (deviceid : 0x60) controllers
*/

/**
 * megasas_issue_polled -       Issues a polling command
 * @instance:                   Adapter soft state
 * @cmd:                        Command packet to be issued 
 *
 * For polling, MFI requires the cmd_status to be set to 0xFF before posting.
 */
static int
megasas_issue_polled(struct megasas_instance *instance, struct megasas_cmd *cmd)
{
        int i;
        u32 msecs = MFI_POLL_TIMEOUT_SECS * 1000;

        struct megasas_header *frame_hdr = &cmd->frame->hdr;

        frame_hdr->cmd_status = 0xFF;
        frame_hdr->flags |= MFI_FRAME_DONT_POST_IN_REPLY_QUEUE;

        /*
         * Issue the frame using inbound queue port
         */
        instance->instancet->fire_cmd(instance,
                        cmd->frame_phys_addr, 0, instance->reg_set);

        /*
         * Wait for cmd_status to change
         */
        for (i = 0; (i < msecs) && (frame_hdr->cmd_status == 0xff); i++) {
                rmb();
                msleep(1);
        }

        if (frame_hdr->cmd_status == 0xff)
                return -ETIME;

        return 0;
}

/**
 * megasas_issue_blocked_cmd -  Synchronous wrapper around regular FW cmds
 * @instance:                   Adapter soft state
 * @cmd:                        Command to be issued
 *
 * This function waits on an event for the command to be returned from ISR.
 * Max wait time is MEGASAS_INTERNAL_CMD_WAIT_TIME secs
 * Used to issue ioctl commands.
 */
static int
megasas_issue_blocked_cmd(struct megasas_instance *instance,
                          struct megasas_cmd *cmd)
{
        cmd->cmd_status = ENODATA;

        instance->instancet->fire_cmd(instance,
                        cmd->frame_phys_addr, 0, instance->reg_set);

        wait_event_timeout(instance->int_cmd_wait_q, (cmd->cmd_status != ENODATA),
                MEGASAS_INTERNAL_CMD_WAIT_TIME*HZ);

        return 0;
}

/**
 * megasas_issue_blocked_abort_cmd -    Aborts previously issued cmd
 * @instance:                           Adapter soft state
 * @cmd_to_abort:                       Previously issued cmd to be aborted
 *
 * MFI firmware can abort previously issued AEN comamnd (automatic event
 * notification). The megasas_issue_blocked_abort_cmd() issues such abort
 * cmd and waits for return status.
 * Max wait time is MEGASAS_INTERNAL_CMD_WAIT_TIME secs
 */
static int
megasas_issue_blocked_abort_cmd(struct megasas_instance *instance,
                                struct megasas_cmd *cmd_to_abort)
{
        struct megasas_cmd *cmd;
        struct megasas_abort_frame *abort_fr;

        cmd = megasas_get_cmd(instance);

        if (!cmd)
                return -1;

        abort_fr = &cmd->frame->abort;

        /*
         * Prepare and issue the abort frame
         */
        abort_fr->cmd = MFI_CMD_ABORT;
        abort_fr->cmd_status = 0xFF;
        abort_fr->flags = 0;
        abort_fr->abort_context = cmd_to_abort->index;
        abort_fr->abort_mfi_phys_addr_lo = cmd_to_abort->frame_phys_addr;
        abort_fr->abort_mfi_phys_addr_hi = 0;

        cmd->sync_cmd = 1;
        cmd->cmd_status = 0xFF;

        instance->instancet->fire_cmd(instance,
                        cmd->frame_phys_addr, 0, instance->reg_set);

        /*
         * Wait for this cmd to complete
         */
        wait_event_timeout(instance->abort_cmd_wait_q, (cmd->cmd_status != 0xFF),
                MEGASAS_INTERNAL_CMD_WAIT_TIME*HZ);

        megasas_return_cmd(instance, cmd);
        return 0;
}

/**
 * megasas_make_sgl32 - Prepares 32-bit SGL
 * @instance:           Adapter soft state
 * @scp:                SCSI command from the mid-layer
 * @mfi_sgl:            SGL to be filled in
 *
 * If successful, this function returns the number of SG elements. Otherwise,
 * it returnes -1.
 */
static int
megasas_make_sgl32(struct megasas_instance *instance, struct scsi_cmnd *scp,
                   union megasas_sgl *mfi_sgl)
{
        int i;
        int sge_count;
        struct scatterlist *os_sgl;

        sge_count = scsi_dma_map(scp);
        BUG_ON(sge_count < 0);

        if (sge_count) {
                scsi_for_each_sg(scp, os_sgl, sge_count, i) {
                        mfi_sgl->sge32[i].length = sg_dma_len(os_sgl);
                        mfi_sgl->sge32[i].phys_addr = sg_dma_address(os_sgl);
                }
        }
        return sge_count;
}

/**
 * megasas_make_sgl64 - Prepares 64-bit SGL
 * @instance:           Adapter soft state
 * @scp:                SCSI command from the mid-layer
 * @mfi_sgl:            SGL to be filled in
 *
 * If successful, this function returns the number of SG elements. Otherwise,
 * it returnes -1.
 */
static int
megasas_make_sgl64(struct megasas_instance *instance, struct scsi_cmnd *scp,
                   union megasas_sgl *mfi_sgl)
{
        int i;
        int sge_count;
        struct scatterlist *os_sgl;

        sge_count = scsi_dma_map(scp);
        BUG_ON(sge_count < 0);

        if (sge_count) {
                scsi_for_each_sg(scp, os_sgl, sge_count, i) {
                        mfi_sgl->sge64[i].length = sg_dma_len(os_sgl);
                        mfi_sgl->sge64[i].phys_addr = sg_dma_address(os_sgl);
                }
        }
        return sge_count;
}

/**
 * megasas_make_sgl_skinny - Prepares IEEE SGL
 * @instance:           Adapter soft state
 * @scp:                SCSI command from the mid-layer
 * @mfi_sgl:            SGL to be filled in
 *
 * If successful, this function returns the number of SG elements. Otherwise,
 * it returnes -1.
 */
static int
megasas_make_sgl_skinny(struct megasas_instance *instance,
                struct scsi_cmnd *scp, union megasas_sgl *mfi_sgl)
{
        int i;
        int sge_count;
        struct scatterlist *os_sgl;

        sge_count = scsi_dma_map(scp);

        if (sge_count) {
                scsi_for_each_sg(scp, os_sgl, sge_count, i) {
                        mfi_sgl->sge_skinny[i].length = sg_dma_len(os_sgl);
                        mfi_sgl->sge_skinny[i].phys_addr =
                                                sg_dma_address(os_sgl);
                }
        }
        return sge_count;
}

 /**
 * megasas_get_frame_count - Computes the number of frames
 * @frame_type          : type of frame- io or pthru frame
 * @sge_count           : number of sg elements
 *
 * Returns the number of frames required for numnber of sge's (sge_count)
 */

static u32 megasas_get_frame_count(struct megasas_instance *instance,
                        u8 sge_count, u8 frame_type)
{
        int num_cnt;
        int sge_bytes;
        u32 sge_sz;
        u32 frame_count=0;

        sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
            sizeof(struct megasas_sge32);

        if (instance->flag_ieee) {
                sge_sz = sizeof(struct megasas_sge_skinny);
        }

        /*
         * Main frame can contain 2 SGEs for 64-bit SGLs and
         * 3 SGEs for 32-bit SGLs for ldio &
         * 1 SGEs for 64-bit SGLs and
         * 2 SGEs for 32-bit SGLs for pthru frame
         */
        if (unlikely(frame_type == PTHRU_FRAME)) {
                if (instance->flag_ieee == 1) {
                        num_cnt = sge_count - 1;
                } else if (IS_DMA64)
                        num_cnt = sge_count - 1;
                else
                        num_cnt = sge_count - 2;
        } else {
                if (instance->flag_ieee == 1) {
                        num_cnt = sge_count - 1;
                } else if (IS_DMA64)
                        num_cnt = sge_count - 2;
                else
                        num_cnt = sge_count - 3;
        }

        if(num_cnt>0){
                sge_bytes = sge_sz * num_cnt;

                frame_count = (sge_bytes / MEGAMFI_FRAME_SIZE) +
                    ((sge_bytes % MEGAMFI_FRAME_SIZE) ? 1 : 0) ;
        }
        /* Main frame */
        frame_count +=1;

        if (frame_count > 7)
                frame_count = 8;
        return frame_count;
}

/**
 * megasas_build_dcdb - Prepares a direct cdb (DCDB) command
 * @instance:           Adapter soft state
 * @scp:                SCSI command
 * @cmd:                Command to be prepared in
 *
 * This function prepares CDB commands. These are typcially pass-through
 * commands to the devices.
 */
static int
megasas_build_dcdb(struct megasas_instance *instance, struct scsi_cmnd *scp,
                   struct megasas_cmd *cmd)
{
        u32 is_logical;
        u32 device_id;
        u16 flags = 0;
        struct megasas_pthru_frame *pthru;

        is_logical = MEGASAS_IS_LOGICAL(scp);
        device_id = MEGASAS_DEV_INDEX(instance, scp);
        pthru = (struct megasas_pthru_frame *)cmd->frame;

        if (scp->sc_data_direction == PCI_DMA_TODEVICE)
                flags = MFI_FRAME_DIR_WRITE;
        else if (scp->sc_data_direction == PCI_DMA_FROMDEVICE)
                flags = MFI_FRAME_DIR_READ;
        else if (scp->sc_data_direction == PCI_DMA_NONE)
                flags = MFI_FRAME_DIR_NONE;

        if (instance->flag_ieee == 1) {
                flags |= MFI_FRAME_IEEE;
        }

        /*
         * Prepare the DCDB frame
         */
        pthru->cmd = (is_logical) ? MFI_CMD_LD_SCSI_IO : MFI_CMD_PD_SCSI_IO;
        pthru->cmd_status = 0x0;
        pthru->scsi_status = 0x0;
        pthru->target_id = device_id;
        pthru->lun = scp->device->lun;
        pthru->cdb_len = scp->cmd_len;
        pthru->timeout = 0;
        pthru->pad_0 = 0;
        pthru->flags = flags;
        pthru->data_xfer_len = scsi_bufflen(scp);

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

        /*
        * If the command is for the tape device, set the
        * pthru timeout to the os layer timeout value.
        */
        if (scp->device->type == TYPE_TAPE) {
                if ((scp->request->timeout / HZ) > 0xFFFF)
                        pthru->timeout = 0xFFFF;
                else
                        pthru->timeout = scp->request->timeout / HZ;
        }

        /*
         * Construct SGL
         */
        if (instance->flag_ieee == 1) {
                pthru->flags |= MFI_FRAME_SGL64;
                pthru->sge_count = megasas_make_sgl_skinny(instance, scp,
                                                      &pthru->sgl);
        } else if (IS_DMA64) {
                pthru->flags |= MFI_FRAME_SGL64;
                pthru->sge_count = megasas_make_sgl64(instance, scp,
                                                      &pthru->sgl);
        } else
                pthru->sge_count = megasas_make_sgl32(instance, scp,
                                                      &pthru->sgl);

        if (pthru->sge_count > instance->max_num_sge) {
                printk(KERN_ERR "megasas: DCDB two many SGE NUM=%x\n",
                        pthru->sge_count);
                return 0;
        }

        /*
         * Sense info specific
         */
        pthru->sense_len = SCSI_SENSE_BUFFERSIZE;
        pthru->sense_buf_phys_addr_hi = 0;
        pthru->sense_buf_phys_addr_lo = cmd->sense_phys_addr;

        /*
         * Compute the total number of frames this command consumes. FW uses
         * this number to pull sufficient number of frames from host memory.
         */
        cmd->frame_count = megasas_get_frame_count(instance, pthru->sge_count,
                                                        PTHRU_FRAME);

        return cmd->frame_count;
}

/**
 * megasas_build_ldio - Prepares IOs to logical devices
 * @instance:           Adapter soft state
 * @scp:                SCSI command
 * @cmd:                Command to be prepared
 *
 * Frames (and accompanying SGLs) for regular SCSI IOs use this function.
 */
static int
megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
                   struct megasas_cmd *cmd)
{
        u32 device_id;
        u8 sc = scp->cmnd[0];
        u16 flags = 0;
        struct megasas_io_frame *ldio;

        device_id = MEGASAS_DEV_INDEX(instance, scp);
        ldio = (struct megasas_io_frame *)cmd->frame;

        if (scp->sc_data_direction == PCI_DMA_TODEVICE)
                flags = MFI_FRAME_DIR_WRITE;
        else if (scp->sc_data_direction == PCI_DMA_FROMDEVICE)
                flags = MFI_FRAME_DIR_READ;

        if (instance->flag_ieee == 1) {
                flags |= MFI_FRAME_IEEE;
        }

        /*
         * Prepare the Logical IO frame: 2nd bit is zero for all read cmds
         */
        ldio->cmd = (sc & 0x02) ? MFI_CMD_LD_WRITE : MFI_CMD_LD_READ;
        ldio->cmd_status = 0x0;
        ldio->scsi_status = 0x0;
        ldio->target_id = device_id;
        ldio->timeout = 0;
        ldio->reserved_0 = 0;
        ldio->pad_0 = 0;
        ldio->flags = flags;
        ldio->start_lba_hi = 0;
        ldio->access_byte = (scp->cmd_len != 6) ? scp->cmnd[1] : 0;

        /*
         * 6-byte READ(0x08) or WRITE(0x0A) cdb
         */
        if (scp->cmd_len == 6) {
                ldio->lba_count = (u32) scp->cmnd[4];
                ldio->start_lba_lo = ((u32) scp->cmnd[1] << 16) |
                    ((u32) scp->cmnd[2] << 8) | (u32) scp->cmnd[3];

                ldio->start_lba_lo &= 0x1FFFFF;
        }

        /*
         * 10-byte READ(0x28) or WRITE(0x2A) cdb
         */
        else if (scp->cmd_len == 10) {
                ldio->lba_count = (u32) scp->cmnd[8] |
                    ((u32) scp->cmnd[7] << 8);
                ldio->start_lba_lo = ((u32) scp->cmnd[2] << 24) |
                    ((u32) scp->cmnd[3] << 16) |
                    ((u32) scp->cmnd[4] << 8) | (u32) scp->cmnd[5];
        }

        /*
         * 12-byte READ(0xA8) or WRITE(0xAA) cdb
         */
        else if (scp->cmd_len == 12) {
                ldio->lba_count = ((u32) scp->cmnd[6] << 24) |
                    ((u32) scp->cmnd[7] << 16) |
                    ((u32) scp->cmnd[8] << 8) | (u32) scp->cmnd[9];

                ldio->start_lba_lo = ((u32) scp->cmnd[2] << 24) |
                    ((u32) scp->cmnd[3] << 16) |
                    ((u32) scp->cmnd[4] << 8) | (u32) scp->cmnd[5];
        }

        /*
         * 16-byte READ(0x88) or WRITE(0x8A) cdb
         */
        else if (scp->cmd_len == 16) {
                ldio->lba_count = ((u32) scp->cmnd[10] << 24) |
                    ((u32) scp->cmnd[11] << 16) |
                    ((u32) scp->cmnd[12] << 8) | (u32) scp->cmnd[13];

                ldio->start_lba_lo = ((u32) scp->cmnd[6] << 24) |
                    ((u32) scp->cmnd[7] << 16) |
                    ((u32) scp->cmnd[8] << 8) | (u32) scp->cmnd[9];

                ldio->start_lba_hi = ((u32) scp->cmnd[2] << 24) |
                    ((u32) scp->cmnd[3] << 16) |
                    ((u32) scp->cmnd[4] << 8) | (u32) scp->cmnd[5];

        }

        /*
         * Construct SGL
         */

        if (instance->flag_ieee) {
                ldio->flags |= MFI_FRAME_SGL64;
                ldio->sge_count = megasas_make_sgl_skinny(instance, scp,
                                              &ldio->sgl);
        } else if (IS_DMA64) {
                ldio->flags |= MFI_FRAME_SGL64;
                ldio->sge_count = megasas_make_sgl64(instance, scp, &ldio->sgl);
        } else
                ldio->sge_count = megasas_make_sgl32(instance, scp, &ldio->sgl);

        if (ldio->sge_count > instance->max_num_sge) {
                printk(KERN_ERR "megasas: build_ld_io: sge_count = %x\n",
                        ldio->sge_count);
                return 0;
        }

        /*
         * Sense info specific
         */
        ldio->sense_len = SCSI_SENSE_BUFFERSIZE;
        ldio->sense_buf_phys_addr_hi = 0;
        ldio->sense_buf_phys_addr_lo = cmd->sense_phys_addr;

        /*
         * Compute the total number of frames this command consumes. FW uses
         * this number to pull sufficient number of frames from host memory.
         */
        cmd->frame_count = megasas_get_frame_count(instance,
                        ldio->sge_count, IO_FRAME);

        return cmd->frame_count;
}

/**
 * megasas_is_ldio -            Checks if the cmd is for logical drive
 * @scmd:                       SCSI command
 *      
 * Called by megasas_queue_command to find out if the command to be queued
 * is a logical drive command   
 */
static inline int megasas_is_ldio(struct scsi_cmnd *cmd)
{
        if (!MEGASAS_IS_LOGICAL(cmd))
                return 0;
        switch (cmd->cmnd[0]) {
        case READ_10:
        case WRITE_10:
        case READ_12:
        case WRITE_12:
        case READ_6:
        case WRITE_6:
        case READ_16:
        case WRITE_16:
                return 1;
        default:
                return 0;
        }
}

 /**
 * megasas_dump_pending_frames -        Dumps the frame address of all pending cmds
 *                                      in FW
 * @instance:                           Adapter soft state
 */
static inline void
megasas_dump_pending_frames(struct megasas_instance *instance)
{
        struct megasas_cmd *cmd;
        int i,n;
        union megasas_sgl *mfi_sgl;
        struct megasas_io_frame *ldio;
        struct megasas_pthru_frame *pthru;
        u32 sgcount;
        u32 max_cmd = instance->max_fw_cmds;

        printk(KERN_ERR "\nmegasas[%d]: Dumping Frame Phys Address of all pending cmds in FW\n",instance->host->host_no);
        printk(KERN_ERR "megasas[%d]: Total OS Pending cmds : %d\n",instance->host->host_no,atomic_read(&instance->fw_outstanding));
        if (IS_DMA64)
                printk(KERN_ERR "\nmegasas[%d]: 64 bit SGLs were sent to FW\n",instance->host->host_no);
        else
                printk(KERN_ERR "\nmegasas[%d]: 32 bit SGLs were sent to FW\n",instance->host->host_no);

        printk(KERN_ERR "megasas[%d]: Pending OS cmds in FW : \n",instance->host->host_no);
        for (i = 0; i < max_cmd; i++) {
                cmd = instance->cmd_list[i];
                if(!cmd->scmd)
                        continue;
                printk(KERN_ERR "megasas[%d]: Frame addr :0x%08lx : ",instance->host->host_no,(unsigned long)cmd->frame_phys_addr);
                if (megasas_is_ldio(cmd->scmd)){
                        ldio = (struct megasas_io_frame *)cmd->frame;
                        mfi_sgl = &ldio->sgl;
                        sgcount = ldio->sge_count;
                        printk(KERN_ERR "megasas[%d]: frame count : 0x%x, Cmd : 0x%x, Tgt id : 0x%x, lba lo : 0x%x, lba_hi : 0x%x, sense_buf addr : 0x%x,sge count : 0x%x\n",instance->host->host_no, cmd->frame_count,ldio->cmd,ldio->target_id, ldio->start_lba_lo,ldio->start_lba_hi,ldio->sense_buf_phys_addr_lo,sgcount);
                }
                else {
                        pthru = (struct megasas_pthru_frame *) cmd->frame;
                        mfi_sgl = &pthru->sgl;
                        sgcount = pthru->sge_count;
                        printk(KERN_ERR "megasas[%d]: frame count : 0x%x, Cmd : 0x%x, Tgt id : 0x%x, lun : 0x%x, cdb_len : 0x%x, data xfer len : 0x%x, sense_buf addr : 0x%x,sge count : 0x%x\n",instance->host->host_no,cmd->frame_count,pthru->cmd,pthru->target_id,pthru->lun,pthru->cdb_len , pthru->data_xfer_len,pthru->sense_buf_phys_addr_lo,sgcount);
                }
        if(megasas_dbg_lvl & MEGASAS_DBG_LVL){
                for (n = 0; n < sgcount; n++){
                        if (IS_DMA64)
                                printk(KERN_ERR "megasas: sgl len : 0x%x, sgl addr : 0x%08lx ",mfi_sgl->sge64[n].length , (unsigned long)mfi_sgl->sge64[n].phys_addr) ;
                        else
                                printk(KERN_ERR "megasas: sgl len : 0x%x, sgl addr : 0x%x ",mfi_sgl->sge32[n].length , mfi_sgl->sge32[n].phys_addr) ;
                        }
                }
                printk(KERN_ERR "\n");
        } /*for max_cmd*/
        printk(KERN_ERR "\nmegasas[%d]: Pending Internal cmds in FW : \n",instance->host->host_no);
        for (i = 0; i < max_cmd; i++) {

                cmd = instance->cmd_list[i];

                if(cmd->sync_cmd == 1){
                        printk(KERN_ERR "0x%08lx : ", (unsigned long)cmd->frame_phys_addr);
                }
        }
        printk(KERN_ERR "megasas[%d]: Dumping Done.\n\n",instance->host->host_no);
}

/**
 * megasas_queue_command -      Queue entry point
 * @scmd:                       SCSI command to be queued
 * @done:                       Callback entry point
 */
static int
megasas_queue_command(struct scsi_cmnd *scmd, void (*done) (struct scsi_cmnd *))
{
        u32 frame_count;
        struct megasas_cmd *cmd;
        struct megasas_instance *instance;

        instance = (struct megasas_instance *)
            scmd->device->host->hostdata;

        /* Don't process if we have already declared adapter dead */
        if (instance->hw_crit_error)
                return SCSI_MLQUEUE_HOST_BUSY;

        scmd->scsi_done = done;
        scmd->result = 0;

        if (MEGASAS_IS_LOGICAL(scmd) &&
            (scmd->device->id >= MEGASAS_MAX_LD || scmd->device->lun)) {
                scmd->result = DID_BAD_TARGET << 16;
                goto out_done;
        }

        switch (scmd->cmnd[0]) {
        case SYNCHRONIZE_CACHE:
                /*
                 * FW takes care of flush cache on its own
                 * No need to send it down
                 */
                scmd->result = DID_OK << 16;
                goto out_done;
        default:
                break;
        }

        cmd = megasas_get_cmd(instance);
        if (!cmd)
                return SCSI_MLQUEUE_HOST_BUSY;

        /*
         * Logical drive command
         */
        if (megasas_is_ldio(scmd))
                frame_count = megasas_build_ldio(instance, scmd, cmd);
        else
                frame_count = megasas_build_dcdb(instance, scmd, cmd);

        if (!frame_count)
                goto out_return_cmd;

        cmd->scmd = scmd;
        scmd->SCp.ptr = (char *)cmd;

        /*
         * Issue the command to the FW
         */
        atomic_inc(&instance->fw_outstanding);

        instance->instancet->fire_cmd(instance, cmd->frame_phys_addr,
                                cmd->frame_count-1, instance->reg_set);
        /*
         * Check if we have pend cmds to be completed
         */
        if (poll_mode_io && atomic_read(&instance->fw_outstanding))
                tasklet_schedule(&instance->isr_tasklet);


        return 0;

 out_return_cmd:
        megasas_return_cmd(instance, cmd);
 out_done:
        done(scmd);
        return 0;
}

static struct megasas_instance *megasas_lookup_instance(u16 host_no)
{
        int i;

        for (i = 0; i < megasas_mgmt_info.max_index; i++) {

                if ((megasas_mgmt_info.instance[i]) &&
                    (megasas_mgmt_info.instance[i]->host->host_no == host_no))
                        return megasas_mgmt_info.instance[i];
        }

        return NULL;
}

static int megasas_slave_configure(struct scsi_device *sdev)
{
        u16             pd_index = 0;
        struct  megasas_instance *instance ;

        instance = megasas_lookup_instance(sdev->host->host_no);

        /*
        * Don't export physical disk devices to the disk driver.
        *
        * FIXME: Currently we don't export them to the midlayer at all.
        *        That will be fixed once LSI engineers have audited the
        *        firmware for possible issues.
        */
        if (sdev->channel < MEGASAS_MAX_PD_CHANNELS &&
                                sdev->type == TYPE_DISK) {
                pd_index = (sdev->channel * MEGASAS_MAX_DEV_PER_CHANNEL) +
                                                                sdev->id;
                if (instance->pd_list[pd_index].driveState ==
                                                MR_PD_STATE_SYSTEM) {
                        blk_queue_rq_timeout(sdev->request_queue,
                                MEGASAS_DEFAULT_CMD_TIMEOUT * HZ);
                        return 0;
                }
                return -ENXIO;
        }

        /*
        * The RAID firmware may require extended timeouts.
        */
        blk_queue_rq_timeout(sdev->request_queue,
                MEGASAS_DEFAULT_CMD_TIMEOUT * HZ);
        return 0;
}

static int megasas_slave_alloc(struct scsi_device *sdev)
{
        u16             pd_index = 0;
        struct megasas_instance *instance ;
        instance = megasas_lookup_instance(sdev->host->host_no);
        if ((sdev->channel < MEGASAS_MAX_PD_CHANNELS) &&
                                (sdev->type == TYPE_DISK)) {
                /*
                 * Open the OS scan to the SYSTEM PD
                 */
                pd_index =
                        (sdev->channel * MEGASAS_MAX_DEV_PER_CHANNEL) +
                        sdev->id;
                if ((instance->pd_list[pd_index].driveState ==
                                        MR_PD_STATE_SYSTEM) &&
                        (instance->pd_list[pd_index].driveType ==
                                                TYPE_DISK)) {
                        return 0;
                }
                return -ENXIO;
        }
        return 0;
}

/**
 * megasas_complete_cmd_dpc      -      Returns FW's controller structure
 * @instance_addr:                      Address of adapter soft state
 *
 * Tasklet to complete cmds
 */
static void megasas_complete_cmd_dpc(unsigned long instance_addr)
{
        u32 producer;
        u32 consumer;
        u32 context;
        struct megasas_cmd *cmd;
        struct megasas_instance *instance =
                                (struct megasas_instance *)instance_addr;
        unsigned long flags;

        /* If we have already declared adapter dead, donot complete cmds */
        if (instance->hw_crit_error)
                return;

        spin_lock_irqsave(&instance->completion_lock, flags);

        producer = *instance->producer;
        consumer = *instance->consumer;

        while (consumer != producer) {
                context = instance->reply_queue[consumer];

                cmd = instance->cmd_list[context];

                megasas_complete_cmd(instance, cmd, DID_OK);

                consumer++;
                if (consumer == (instance->max_fw_cmds + 1)) {
                        consumer = 0;
                }
        }

        *instance->consumer = producer;

        spin_unlock_irqrestore(&instance->completion_lock, flags);

        /*
         * Check if we can restore can_queue
         */
        if (instance->flag & MEGASAS_FW_BUSY
                && time_after(jiffies, instance->last_time + 5 * HZ)
                && atomic_read(&instance->fw_outstanding) < 17) {

                spin_lock_irqsave(instance->host->host_lock, flags);
                instance->flag &= ~MEGASAS_FW_BUSY;
                if ((instance->pdev->device ==
                        PCI_DEVICE_ID_LSI_SAS0073SKINNY) ||
                        (instance->pdev->device ==
                        PCI_DEVICE_ID_LSI_SAS0071SKINNY)) {
                        instance->host->can_queue =
                                instance->max_fw_cmds - MEGASAS_SKINNY_INT_CMDS;
                } else
                        instance->host->can_queue =
                                instance->max_fw_cmds - MEGASAS_INT_CMDS;

                spin_unlock_irqrestore(instance->host->host_lock, flags);
        }
}

/**
 * megasas_wait_for_outstanding -       Wait for all outstanding cmds
 * @instance:                           Adapter soft state
 *
 * This function waits for upto MEGASAS_RESET_WAIT_TIME seconds for FW to
 * complete all its outstanding commands. Returns error if one or more IOs
 * are pending after this time period. It also marks the controller dead.
 */
static int megasas_wait_for_outstanding(struct megasas_instance *instance)
{
        int i;
        u32 wait_time = MEGASAS_RESET_WAIT_TIME;

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

                int outstanding = atomic_read(&instance->fw_outstanding);

                if (!outstanding)
                        break;

                if (!(i % MEGASAS_RESET_NOTICE_INTERVAL)) {
                        printk(KERN_NOTICE "megasas: [%2d]waiting for %d "
                               "commands to complete\n",i,outstanding);
                        /*
                         * Call cmd completion routine. Cmd to be
                         * be completed directly without depending on isr.
                         */
                        megasas_complete_cmd_dpc((unsigned long)instance);
                }

                msleep(1000);
        }

        if (atomic_read(&instance->fw_outstanding)) {
                /*
                * Send signal to FW to stop processing any pending cmds.
                * The controller will be taken offline by the OS now.
                */
                if ((instance->pdev->device ==
                        PCI_DEVICE_ID_LSI_SAS0073SKINNY) ||
                        (instance->pdev->device ==
                        PCI_DEVICE_ID_LSI_SAS0071SKINNY)) {
                        writel(MFI_STOP_ADP,
                                &instance->reg_set->reserved_0[0]);
                } else {
                        writel(MFI_STOP_ADP,
                                &instance->reg_set->inbound_doorbell);
                }
                megasas_dump_pending_frames(instance);
                instance->hw_crit_error = 1;
                return FAILED;
        }

        return SUCCESS;
}

/**
 * megasas_generic_reset -      Generic reset routine
 * @scmd:                       Mid-layer SCSI command
 *
 * This routine implements a generic reset handler for device, bus and host
 * reset requests. Device, bus and host specific reset handlers can use this
 * function after they do their specific tasks.
 */
static int megasas_generic_reset(struct scsi_cmnd *scmd)
{
        int ret_val;
        struct megasas_instance *instance;

        instance = (struct megasas_instance *)scmd->device->host->hostdata;

        scmd_printk(KERN_NOTICE, scmd, "megasas: RESET -%ld cmd=%x retries=%x\n",
                 scmd->serial_number, scmd->cmnd[0], scmd->retries);

        if (instance->hw_crit_error) {
                printk(KERN_ERR "megasas: cannot recover from previous reset "
                       "failures\n");
                return FAILED;
        }

        ret_val = megasas_wait_for_outstanding(instance);
        if (ret_val == SUCCESS)
                printk(KERN_NOTICE "megasas: reset successful \n");
        else
                printk(KERN_ERR "megasas: failed to do reset\n");

        return ret_val;
}

/**
 * megasas_reset_timer - quiesce the adapter if required
 * @scmd:               scsi cmnd
 *
 * Sets the FW busy flag and reduces the host->can_queue if the
 * cmd has not been completed within the timeout period.
 */
static enum
blk_eh_timer_return megasas_reset_timer(struct scsi_cmnd *scmd)
{
        struct megasas_cmd *cmd = (struct megasas_cmd *)scmd->SCp.ptr;
        struct megasas_instance *instance;
        unsigned long flags;

        if (time_after(jiffies, scmd->jiffies_at_alloc +
                                (MEGASAS_DEFAULT_CMD_TIMEOUT * 2) * HZ)) {
                return BLK_EH_NOT_HANDLED;
        }

        instance = cmd->instance;
        if (!(instance->flag & MEGASAS_FW_BUSY)) {
                /* FW is busy, throttle IO */
                spin_lock_irqsave(instance->host->host_lock, flags);

                instance->host->can_queue = 16;
                instance->last_time = jiffies;
                instance->flag |= MEGASAS_FW_BUSY;

                spin_unlock_irqrestore(instance->host->host_lock, flags);
        }
        return BLK_EH_RESET_TIMER;
}

/**
 * megasas_reset_device -       Device reset handler entry point
 */
static int megasas_reset_device(struct scsi_cmnd *scmd)
{
        int ret;

        /*
         * First wait for all commands to complete
         */
        ret = megasas_generic_reset(scmd);

        return ret;
}

/**
 * megasas_reset_bus_host -     Bus & host reset handler entry point
 */
static int megasas_reset_bus_host(struct scsi_cmnd *scmd)
{
        int ret;

        /*
         * First wait for all commands to complete
         */
        ret = megasas_generic_reset(scmd);

        return ret;
}

/**
 * megasas_bios_param - Returns disk geometry for a disk
 * @sdev:               device handle
 * @bdev:               block device
 * @capacity:           drive capacity
 * @geom:               geometry parameters
 */
static int
megasas_bios_param(struct scsi_device *sdev, struct block_device *bdev,
                 sector_t capacity, int geom[])
{
        int heads;
        int sectors;
        sector_t cylinders;
        unsigned long tmp;
        /* Default heads (64) & sectors (32) */
        heads = 64;
        sectors = 32;

        tmp = heads * sectors;
        cylinders = capacity;

        sector_div(cylinders, tmp);

        /*
         * Handle extended translation size for logical drives > 1Gb
         */

        if (capacity >= 0x200000) {
                heads = 255;
                sectors = 63;
                tmp = heads*sectors;
                cylinders = capacity;
                sector_div(cylinders, tmp);
        }

        geom[0] = heads;
        geom[1] = sectors;
        geom[2] = cylinders;

        return 0;
}

static void megasas_aen_polling(struct work_struct *work);

/**
 * megasas_service_aen -        Processes an event notification
 * @instance:                   Adapter soft state
 * @cmd:                        AEN command completed by the ISR
 *
 * For AEN, driver sends a command down to FW that is held by the FW till an
 * event occurs. When an event of interest occurs, FW completes the command
 * that it was previously holding.
 *
 * This routines sends SIGIO signal to processes that have registered with the
 * driver for AEN.
 */
static void
megasas_service_aen(struct megasas_instance *instance, struct megasas_cmd *cmd)
{
        unsigned long flags;
        /*
         * Don't signal app if it is just an aborted previously registered aen
         */
        if ((!cmd->abort_aen) && (instance->unload == 0)) {
                spin_lock_irqsave(&poll_aen_lock, flags);
                megasas_poll_wait_aen = 1;
                spin_unlock_irqrestore(&poll_aen_lock, flags);
                wake_up(&megasas_poll_wait);
                kill_fasync(&megasas_async_queue, SIGIO, POLL_IN);
        }
        else
                cmd->abort_aen = 0;

        instance->aen_cmd = NULL;
        megasas_return_cmd(instance, cmd);

        if (instance->unload == 0) {
                struct megasas_aen_event *ev;
                ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
                if (!ev) {
                        printk(KERN_ERR "megasas_service_aen: out of memory\n");
                } else {
                        ev->instance = instance;
                        instance->ev = ev;
                        INIT_WORK(&ev->hotplug_work, megasas_aen_polling);
                        schedule_delayed_work(
                                (struct delayed_work *)&ev->hotplug_work, 0);
                }
        }
}

/*
 * Scsi host template for megaraid_sas driver
 */
static struct scsi_host_template megasas_template = {

        .module = THIS_MODULE,
        .name = "LSI SAS based MegaRAID driver",
        .proc_name = "megaraid_sas",
        .slave_configure = megasas_slave_configure,
        .slave_alloc = megasas_slave_alloc,
        .queuecommand = megasas_queue_command,
        .eh_device_reset_handler = megasas_reset_device,
        .eh_bus_reset_handler = megasas_reset_bus_host,
        .eh_host_reset_handler = megasas_reset_bus_host,
        .eh_timed_out = megasas_reset_timer,
        .bios_param = megasas_bios_param,
        .use_clustering = ENABLE_CLUSTERING,
};

/**
 * megasas_complete_int_cmd -   Completes an internal command
 * @instance:                   Adapter soft state
 * @cmd:                        Command to be completed
 *
 * The megasas_issue_blocked_cmd() function waits for a command to complete
 * after it issues a command. This function wakes up that waiting routine by
 * calling wake_up() on the wait queue.
 */
static void
megasas_complete_int_cmd(struct megasas_instance *instance,
                         struct megasas_cmd *cmd)
{
        cmd->cmd_status = cmd->frame->io.cmd_status;

        if (cmd->cmd_status == ENODATA) {
                cmd->cmd_status = 0;
        }
        wake_up(&instance->int_cmd_wait_q);
}

/**
 * megasas_complete_abort -     Completes aborting a command
 * @instance:                   Adapter soft state
 * @cmd:                        Cmd that was issued to abort another cmd
 *
 * The megasas_issue_blocked_abort_cmd() function waits on abort_cmd_wait_q 
 * after it issues an abort on a previously issued command. This function 
 * wakes up all functions waiting on the same wait queue.
 */
static void
megasas_complete_abort(struct megasas_instance *instance,
                       struct megasas_cmd *cmd)
{
        if (cmd->sync_cmd) {
                cmd->sync_cmd = 0;
                cmd->cmd_status = 0;
                wake_up(&instance->abort_cmd_wait_q);
        }

        return;
}

/**
 * megasas_complete_cmd -       Completes a command
 * @instance:                   Adapter soft state
 * @cmd:                        Command to be completed
 * @alt_status:                 If non-zero, use this value as status to 
 *                              SCSI mid-layer instead of the value returned
 *                              by the FW. This should be used if caller wants
 *                              an alternate status (as in the case of aborted
 *                              commands)
 */
static void
megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd,
                     u8 alt_status)
{
        int exception = 0;
        struct megasas_header *hdr = &cmd->frame->hdr;
        unsigned long flags;

        if (cmd->scmd)
                cmd->scmd->SCp.ptr = NULL;

        switch (hdr->cmd) {

        case MFI_CMD_PD_SCSI_IO:
        case MFI_CMD_LD_SCSI_IO:

                /*
                 * MFI_CMD_PD_SCSI_IO and MFI_CMD_LD_SCSI_IO could have been
                 * issued either through an IO path or an IOCTL path. If it
                 * was via IOCTL, we will send it to internal completion.
                 */
                if (cmd->sync_cmd) {
                        cmd->sync_cmd = 0;
                        megasas_complete_int_cmd(instance, cmd);
                        break;
                }

        case MFI_CMD_LD_READ:
        case MFI_CMD_LD_WRITE:

                if (alt_status) {
                        cmd->scmd->result = alt_status << 16;
                        exception = 1;
                }

                if (exception) {

                        atomic_dec(&instance->fw_outstanding);

                        scsi_dma_unmap(cmd->scmd);
                        cmd->scmd->scsi_done(cmd->scmd);
                        megasas_return_cmd(instance, cmd);

                        break;
                }

                switch (hdr->cmd_status) {

                case MFI_STAT_OK:
                        cmd->scmd->result = DID_OK << 16;
                        break;

                case MFI_STAT_SCSI_IO_FAILED:
                case MFI_STAT_LD_INIT_IN_PROGRESS:
                        cmd->scmd->result =
                            (DID_ERROR << 16) | hdr->scsi_status;
                        break;

                case MFI_STAT_SCSI_DONE_WITH_ERROR:

                        cmd->scmd->result = (DID_OK << 16) | hdr->scsi_status;

                        if (hdr->scsi_status == SAM_STAT_CHECK_CONDITION) {
                                memset(cmd->scmd->sense_buffer, 0,
                                       SCSI_SENSE_BUFFERSIZE);
                                memcpy(cmd->scmd->sense_buffer, cmd->sense,
                                       hdr->sense_len);

                                cmd->scmd->result |= DRIVER_SENSE << 24;
                        }

                        break;

                case MFI_STAT_LD_OFFLINE:
                case MFI_STAT_DEVICE_NOT_FOUND:
                        cmd->scmd->result = DID_BAD_TARGET << 16;
                        break;

                default:
                        printk(KERN_DEBUG "megasas: MFI FW status %#x\n",
                               hdr->cmd_status);
                        cmd->scmd->result = DID_ERROR << 16;
                        break;
                }

                atomic_dec(&instance->fw_outstanding);

                scsi_dma_unmap(cmd->scmd);
                cmd->scmd->scsi_done(cmd->scmd);
                megasas_return_cmd(instance, cmd);

                break;

        case MFI_CMD_SMP:
        case MFI_CMD_STP:
        case MFI_CMD_DCMD:
                if (cmd->frame->dcmd.opcode == MR_DCMD_CTRL_EVENT_GET_INFO ||
                        cmd->frame->dcmd.opcode == MR_DCMD_CTRL_EVENT_GET) {
                        spin_lock_irqsave(&poll_aen_lock, flags);
                        megasas_poll_wait_aen = 0;
                        spin_unlock_irqrestore(&poll_aen_lock, flags);
                }

                /*
                 * See if got an event notification
                 */
                if (cmd->frame->dcmd.opcode == MR_DCMD_CTRL_EVENT_WAIT)
                        megasas_service_aen(instance, cmd);
                else
                        megasas_complete_int_cmd(instance, cmd);

                break;

        case MFI_CMD_ABORT:
                /*
                 * Cmd issued to abort another cmd returned
                 */
                megasas_complete_abort(instance, cmd);
                break;

        default:
                printk("megasas: Unknown command completed! [0x%X]\n",
                       hdr->cmd);
                break;
        }
}

/**
 * megasas_deplete_reply_queue -        Processes all completed commands
 * @instance:                           Adapter soft state
 * @alt_status:                         Alternate status to be returned to
 *                                      SCSI mid-layer instead of the status
 *                                      returned by the FW
 */
static int
megasas_deplete_reply_queue(struct megasas_instance *instance, u8 alt_status)
{
        /*
         * Check if it is our interrupt
         * Clear the interrupt 
         */
        if(instance->instancet->clear_intr(instance->reg_set))
                return IRQ_NONE;

        if (instance->hw_crit_error)
                goto out_done;
        /*
         * Schedule the tasklet for cmd completion
         */
        tasklet_schedule(&instance->isr_tasklet);
out_done:
        return IRQ_HANDLED;
}

/**
 * megasas_isr - isr entry point
 */
static irqreturn_t megasas_isr(int irq, void *devp)
{
        return megasas_deplete_reply_queue((struct megasas_instance *)devp,
                                           DID_OK);
}

/**
 * megasas_transition_to_ready -        Move the FW to READY state
 * @instance:                           Adapter soft state
 *
 * During the initialization, FW passes can potentially be in any one of
 * several possible states. If the FW in operational, waiting-for-handshake
 * states, driver must take steps to bring it to ready state. Otherwise, it
 * has to wait for the ready state.
 */
static int
megasas_transition_to_ready(struct megasas_instance* instance)
{
        int i;
        u8 max_wait;
        u32 fw_state;
        u32 cur_state;
        u32 abs_state, curr_abs_state;

        fw_state = instance->instancet->read_fw_status_reg(instance->reg_set) & MFI_STATE_MASK;

        if (fw_state != MFI_STATE_READY)
                printk(KERN_INFO "megasas: Waiting for FW to come to ready"
                       " state\n");

        while (fw_state != MFI_STATE_READY) {

                abs_state =
                instance->instancet->read_fw_status_reg(instance->reg_set);

                switch (fw_state) {

                case MFI_STATE_FAULT:

                        printk(KERN_DEBUG "megasas: FW in FAULT state!!\n");
                        return -ENODEV;

                case MFI_STATE_WAIT_HANDSHAKE:
                        /*
                         * Set the CLR bit in inbound doorbell
                         */
                        if ((instance->pdev->device ==
                                PCI_DEVICE_ID_LSI_SAS0073SKINNY) ||
                                (instance->pdev->device ==
                                PCI_DEVICE_ID_LSI_SAS0071SKINNY)) {

                                writel(
                                  MFI_INIT_CLEAR_HANDSHAKE|MFI_INIT_HOTPLUG,
                                  &instance->reg_set->reserved_0[0]);
                        } else {
                                writel(
                                    MFI_INIT_CLEAR_HANDSHAKE|MFI_INIT_HOTPLUG,
                                        &instance->reg_set->inbound_doorbell);
                        }

                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_WAIT_HANDSHAKE;
                        break;

                case MFI_STATE_BOOT_MESSAGE_PENDING:
                        if ((instance->pdev->device ==
                                PCI_DEVICE_ID_LSI_SAS0073SKINNY) ||
                        (instance->pdev->device ==
                                PCI_DEVICE_ID_LSI_SAS0071SKINNY)) {
                                writel(MFI_INIT_HOTPLUG,
                                &instance->reg_set->reserved_0[0]);
                        } else
                                writel(MFI_INIT_HOTPLUG,
                                        &instance->reg_set->inbound_doorbell);

                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_BOOT_MESSAGE_PENDING;
                        break;

                case MFI_STATE_OPERATIONAL:
                        /*
                         * Bring it to READY state; assuming max wait 10 secs
                         */
                        instance->instancet->disable_intr(instance->reg_set);
                        if ((instance->pdev->device ==
                                PCI_DEVICE_ID_LSI_SAS0073SKINNY) ||
                                (instance->pdev->device ==
                                PCI_DEVICE_ID_LSI_SAS0071SKINNY)) {
                                writel(MFI_RESET_FLAGS,
                                        &instance->reg_set->reserved_0[0]);
                        } else
                                writel(MFI_RESET_FLAGS,
                                        &instance->reg_set->inbound_doorbell);

                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_OPERATIONAL;
                        break;

                case MFI_STATE_UNDEFINED:
                        /*
                         * This state should not last for more than 2 seconds
                         */
                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_UNDEFINED;
                        break;

                case MFI_STATE_BB_INIT:
                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_BB_INIT;
                        break;

                case MFI_STATE_FW_INIT:
                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_FW_INIT;
                        break;

                case MFI_STATE_FW_INIT_2:
                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_FW_INIT_2;
                        break;

                case MFI_STATE_DEVICE_SCAN:
                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_DEVICE_SCAN;
                        break;

                case MFI_STATE_FLUSH_CACHE:
                        max_wait = MEGASAS_RESET_WAIT_TIME;
                        cur_state = MFI_STATE_FLUSH_CACHE;
                        break;

                default:
                        printk(KERN_DEBUG "megasas: Unknown state 0x%x\n",
                               fw_state);
                        return -ENODEV;
                }

                /*
                 * The cur_state should not last for more than max_wait secs
                 */
                for (i = 0; i < (max_wait * 1000); i++) {
                        fw_state = instance->instancet->read_fw_status_reg(instance->reg_set) &  
                                        MFI_STATE_MASK ;
                curr_abs_state =
                instance->instancet->read_fw_status_reg(instance->reg_set);

                        if (abs_state == curr_abs_state) {
                                msleep(1);
                        } else
                                break;
                }

                /*
                 * Return error if fw_state hasn't changed after max_wait
                 */
                if (curr_abs_state == abs_state) {
                        printk(KERN_DEBUG "FW state [%d] hasn't changed "
                               "in %d secs\n", fw_state, max_wait);
                        return -ENODEV;
                }
        };
        printk(KERN_INFO "megasas: FW now in Ready state\n");

        return 0;
}

/**
 * megasas_teardown_frame_pool -        Destroy the cmd frame DMA pool
 * @instance:                           Adapter soft state
 */
static void megasas_teardown_frame_pool(struct megasas_instance *instance)
{
        int i;
        u32 max_cmd = instance->max_fw_cmds;
        struct megasas_cmd *cmd;

        if (!instance->frame_dma_pool)
                return;

        /*
         * Return all frames to pool
         */
        for (i = 0; i < max_cmd; i++) {

                cmd = instance->cmd_list[i];

                if (cmd->frame)
                        pci_pool_free(instance->frame_dma_pool, cmd->frame,
                                      cmd->frame_phys_addr);

                if (cmd->sense)
                        pci_pool_free(instance->sense_dma_pool, cmd->sense,
                                      cmd->sense_phys_addr);
        }

        /*
         * Now destroy the pool itself
         */
        pci_pool_destroy(instance->frame_dma_pool);
        pci_pool_destroy(instance->sense_dma_pool);

        instance->frame_dma_pool = NULL;
        instance->sense_dma_pool = NULL;
}

/**
 * megasas_create_frame_pool -  Creates DMA pool for cmd frames
 * @instance:                   Adapter soft state
 *
 * Each command packet has an embedded DMA memory buffer that is used for
 * filling MFI frame and the SG list that immediately follows the frame. This
 * function creates those DMA memory buffers for each command packet by using
 * PCI pool facility.
 */
static int megasas_create_frame_pool(struct megasas_instance *instance)
{
        int i;
        u32 max_cmd;
        u32 sge_sz;
        u32 sgl_sz;
        u32 total_sz;
        u32 frame_count;
        struct megasas_cmd *cmd;

        max_cmd = instance->max_fw_cmds;

        /*
         * Size of our frame is 64 bytes for MFI frame, followed by max SG
         * elements and finally SCSI_SENSE_BUFFERSIZE bytes for sense buffer
         */
        sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
            sizeof(struct megasas_sge32);

        if (instance->flag_ieee) {
                sge_sz = sizeof(struct megasas_sge_skinny);
        }

        /*
         * Calculated the number of 64byte frames required for SGL
         */
        sgl_sz = sge_sz * instance->max_num_sge;
        frame_count = (sgl_sz + MEGAMFI_FRAME_SIZE - 1) / MEGAMFI_FRAME_SIZE;

        /*
         * We need one extra frame for the MFI command
         */
        frame_count++;

        total_sz = MEGAMFI_FRAME_SIZE * frame_count;
        /*
         * Use DMA pool facility provided by PCI layer
         */
        instance->frame_dma_pool = pci_pool_create("megasas frame pool",
                                                   instance->pdev, total_sz, 64,
                                                   0);

        if (!instance->frame_dma_pool) {
                printk(KERN_DEBUG "megasas: failed to setup frame pool\n");
                return -ENOMEM;
        }

        instance->sense_dma_pool = pci_pool_create("megasas sense pool",
                                                   instance->pdev, 128, 4, 0);

        if (!instance->sense_dma_pool) {
                printk(KERN_DEBUG "megasas: failed to setup sense pool\n");

                pci_pool_destroy(instance->frame_dma_pool);
                instance->frame_dma_pool = NULL;

                return -ENOMEM;
        }

        /*
         * Allocate and attach a frame to each of the commands in cmd_list.
         * By making cmd->index as the context instead of the &cmd, we can
         * always use 32bit context regardless of the architecture
         */
        for (i = 0; i < max_cmd; i++) {

                cmd = instance->cmd_list[i];

                cmd->frame = pci_pool_alloc(instance->frame_dma_pool,
                                            GFP_KERNEL, &cmd->frame_phys_addr);

                cmd->sense = pci_pool_alloc(instance->sense_dma_pool,
                                            GFP_KERNEL, &cmd->sense_phys_addr);

                /*
                 * megasas_teardown_frame_pool() takes care of freeing
                 * whatever has been allocated
                 */
                if (!cmd->frame || !cmd->sense) {
                        printk(KERN_DEBUG "megasas: pci_pool_alloc failed \n");
                        megasas_teardown_frame_pool(instance);
                        return -ENOMEM;
                }

                cmd->frame->io.context = cmd->index;
                cmd->frame->io.pad_0 = 0;
        }

        return 0;
}

/**
 * megasas_free_cmds -  Free all the cmds in the free cmd pool
 * @instance:           Adapter soft state
 */
static void megasas_free_cmds(struct megasas_instance *instance)
{
        int i;
        /* First free the MFI frame pool */
        megasas_teardown_frame_pool(instance);

        /* Free all the commands in the cmd_list */
        for (i = 0; i < instance->max_fw_cmds; i++)
                kfree(instance->cmd_list[i]);

        /* Free the cmd_list buffer itself */
        kfree(instance->cmd_list);
        instance->cmd_list = NULL;

        INIT_LIST_HEAD(&instance->cmd_pool);
}

/**
 * megasas_alloc_cmds - Allocates the command packets
 * @instance:           Adapter soft state
 *
 * Each command that is issued to the FW, whether IO commands from the OS or
 * internal commands like IOCTLs, are wrapped in local data structure called
 * megasas_cmd. The frame embedded in this megasas_cmd is actually issued to
 * the FW.
 *
 * Each frame has a 32-bit field called context (tag). This context is used
 * to get back the megasas_cmd from the frame when a frame gets completed in
 * the ISR. Typically the address of the megasas_cmd itself would be used as
 * the context. But we wanted to keep the differences between 32 and 64 bit
 * systems to the mininum. We always use 32 bit integers for the context. In
 * this driver, the 32 bit values are the indices into an array cmd_list.
 * This array is used only to look up the megasas_cmd given the context. The
 * free commands themselves are maintained in a linked list called cmd_pool.
 */
static int megasas_alloc_cmds(struct megasas_instance *instance)
{
        int i;
        int j;
        u32 max_cmd;
        struct megasas_cmd *cmd;

        max_cmd = instance->max_fw_cmds;

        /*
         * instance->cmd_list is an array of struct megasas_cmd pointers.
         * Allocate the dynamic array first and then allocate individual
         * commands.
         */
        instance->cmd_list = kcalloc(max_cmd, sizeof(struct megasas_cmd*), GFP_KERNEL);

        if (!instance->cmd_list) {
                printk(KERN_DEBUG "megasas: out of memory\n");
                return -ENOMEM;
        }


        for (i = 0; i < max_cmd; i++) {
                instance->cmd_list[i] = kmalloc(sizeof(struct megasas_cmd),
                                                GFP_KERNEL);

                if (!instance->cmd_list[i]) {

                        for (j = 0; j < i; j++)
                                kfree(instance->cmd_list[j]);

                        kfree(instance->cmd_list);
                        instance->cmd_list = NULL;

                        return -ENOMEM;
                }
        }

        /*
         * Add all the commands to command pool (instance->cmd_pool)
         */
        for (i = 0; i < max_cmd; i++) {
                cmd = instance->cmd_list[i];
                memset(cmd, 0, sizeof(struct megasas_cmd));
                cmd->index = i;
                cmd->instance = instance;

                list_add_tail(&cmd->list, &instance->cmd_pool);
        }

        /*
         * Create a frame pool and assign one frame to each cmd
         */
        if (megasas_create_frame_pool(instance)) {
                printk(KERN_DEBUG "megasas: Error creating frame DMA pool\n");
                megasas_free_cmds(instance);
        }

        return 0;
}

/*
 * megasas_get_pd_list_info -   Returns FW's pd_list structure
 * @instance:                           Adapter soft state
 * @pd_list:                            pd_list structure
 *
 * Issues an internal command (DCMD) to get the FW's controller PD
 * list structure.  This information is mainly used to find out SYSTEM
 * supported by the FW.
 */
static int
megasas_get_pd_list(struct megasas_instance *instance)
{
        int ret = 0, pd_index = 0;
        struct megasas_cmd *cmd;
        struct megasas_dcmd_frame *dcmd;
        struct MR_PD_LIST *ci;
        struct MR_PD_ADDRESS *pd_addr;
        dma_addr_t ci_h = 0;

        cmd = megasas_get_cmd(instance);

        if (!cmd) {
                printk(KERN_DEBUG "megasas (get_pd_list): Failed to get cmd\n");
                return -ENOMEM;
        }

        dcmd = &cmd->frame->dcmd;

        ci = pci_alloc_consistent(instance->pdev,
                  MEGASAS_MAX_PD * sizeof(struct MR_PD_LIST), &ci_h);

        if (!ci) {
                printk(KERN_DEBUG "Failed to alloc mem for pd_list\n");
                megasas_return_cmd(instance, cmd);
                return -ENOMEM;
        }

        memset(ci, 0, sizeof(*ci));
        memset(dcmd->mbox.b, 0, MFI_MBOX_SIZE);

        dcmd->mbox.b[0] = MR_PD_QUERY_TYPE_EXPOSED_TO_HOST;
        dcmd->mbox.b[1] = 0;
        dcmd->cmd = MFI_CMD_DCMD;
        dcmd->cmd_status = 0xFF;
        dcmd->sge_count = 1;
        dcmd->flags = MFI_FRAME_DIR_READ;
        dcmd->timeout = 0;
        dcmd->pad_0 = 0;
        dcmd->data_xfer_len = MEGASAS_MAX_PD * sizeof(struct MR_PD_LIST);
        dcmd->opcode = MR_DCMD_PD_LIST_QUERY;
        dcmd->sgl.sge32[0].phys_addr = ci_h;
        dcmd->sgl.sge32[0].length = MEGASAS_MAX_PD * sizeof(struct MR_PD_LIST);

        if (!megasas_issue_polled(instance, cmd)) {
                ret = 0;
        } else {
                ret = -1;
        }

        /*
        * the following function will get the instance PD LIST.
        */

        pd_addr = ci->addr;

        if ( ret == 0 &&
                (ci->count <
                  (MEGASAS_MAX_PD_CHANNELS * MEGASAS_MAX_DEV_PER_CHANNEL))) {

                memset(instance->pd_list, 0,
                        MEGASAS_MAX_PD * sizeof(struct megasas_pd_list));

                for (pd_index = 0; pd_index < ci->count; pd_index++) {

                        instance->pd_list[pd_addr->deviceId].tid        =
                                                        pd_addr->deviceId;
                        instance->pd_list[pd_addr->deviceId].driveType  =
                                                        pd_addr->scsiDevType;
                        instance->pd_list[pd_addr->deviceId].driveState =
                                                        MR_PD_STATE_SYSTEM;
                        pd_addr++;
                }
        }

        pci_free_consistent(instance->pdev,
                                MEGASAS_MAX_PD * sizeof(struct MR_PD_LIST),
                                ci, ci_h);
        megasas_return_cmd(instance, cmd);

        return ret;
}

/*
 * megasas_get_ld_list_info -   Returns FW's ld_list structure
 * @instance:                           Adapter soft state
 * @ld_list:                            ld_list structure
 *
 * Issues an internal command (DCMD) to get the FW's controller PD
 * list structure.  This information is mainly used to find out SYSTEM
 * supported by the FW.
 */
static int
megasas_get_ld_list(struct megasas_instance *instance)
{
        int ret = 0, ld_index = 0, ids = 0;
        struct megasas_cmd *cmd;
        struct megasas_dcmd_frame *dcmd;
        struct MR_LD_LIST *ci;
        dma_addr_t ci_h = 0;

        cmd = megasas_get_cmd(instance);

        if (!cmd) {
                printk(KERN_DEBUG "megasas_get_ld_list: Failed to get cmd\n");
                return -ENOMEM;
        }

        dcmd = &cmd->frame->dcmd;

        ci = pci_alloc_consistent(instance->pdev,
                                sizeof(struct MR_LD_LIST),
                                &ci_h);

        if (!ci) {
                printk(KERN_DEBUG "Failed to alloc mem in get_ld_list\n");
                megasas_return_cmd(instance, cmd);
                return -ENOMEM;
        }

        memset(ci, 0, sizeof(*ci));
        memset(dcmd->mbox.b, 0, MFI_MBOX_SIZE);

        dcmd->cmd = MFI_CMD_DCMD;
        dcmd->cmd_status = 0xFF;
        dcmd->sge_count = 1;
        dcmd->flags = MFI_FRAME_DIR_READ;
        dcmd->timeout = 0;
        dcmd->data_xfer_len = sizeof(struct MR_LD_LIST);
        dcmd->opcode = MR_DCMD_LD_GET_LIST;
        dcmd->sgl.sge32[0].phys_addr = ci_h;
        dcmd->sgl.sge32[0].length = sizeof(struct MR_LD_LIST);
        dcmd->pad_0  = 0;

        if (!megasas_issue_polled(instance, cmd)) {
                ret = 0;
        } else {
                ret = -1;
        }

        /* the following function will get the instance PD LIST */

        if ((ret == 0) && (ci->ldCount < MAX_LOGICAL_DRIVES)) {
                memset(instance->ld_ids, 0xff, MEGASAS_MAX_LD_IDS);

                for (ld_index = 0; ld_index < ci->ldCount; ld_index++) {
                        if (ci->ldList[ld_index].state != 0) {
                                ids = ci->ldList[ld_index].ref.targetId;
                                instance->ld_ids[ids] =
                                        ci->ldList[ld_index].ref.targetId;
                        }
                }
        }

        pci_free_consistent(instance->pdev,
                                sizeof(struct MR_LD_LIST),
                                ci,
                                ci_h);

        megasas_return_cmd(instance, cmd);
        return ret;
}

/**
 * megasas_get_controller_info -        Returns FW's controller structure
 * @instance:                           Adapter soft state
 * @ctrl_info:                          Controller information structure
 *
 * Issues an internal command (DCMD) to get the FW's controller structure.
 * This information is mainly used to find out the maximum IO transfer per
 * command supported by the FW.
 */
static int
megasas_get_ctrl_info(struct megasas_instance *instance,
                      struct megasas_ctrl_info *ctrl_info)
{
        int ret = 0;
        struct megasas_cmd *cmd;
        struct megasas_dcmd_frame *dcmd;
        struct megasas_ctrl_info *ci;
        dma_addr_t ci_h = 0;

        cmd = megasas_get_cmd(instance);

        if (!cmd) {
                printk(KERN_DEBUG "megasas: Failed to get a free cmd\n");
                return -ENOMEM;
        }

        dcmd = &cmd->frame->dcmd;

        ci = pci_alloc_consistent(instance->pdev,
                                  sizeof(struct megasas_ctrl_info), &ci_h);

        if (!ci) {
                printk(KERN_DEBUG "Failed to alloc mem for ctrl info\n");
                megasas_return_cmd(instance, cmd);
                return -ENOMEM;
        }

        memset(ci, 0, sizeof(*ci));
        memset(dcmd->mbox.b, 0, MFI_MBOX_SIZE);

        dcmd->cmd = MFI_CMD_DCMD;
        dcmd->cmd_status = 0xFF;
        dcmd->sge_count = 1;
        dcmd->flags = MFI_FRAME_DIR_READ;
        dcmd->timeout = 0;
        dcmd->pad_0 = 0;
        dcmd->data_xfer_len = sizeof(struct megasas_ctrl_info);
        dcmd->opcode = MR_DCMD_CTRL_GET_INFO;
        dcmd->sgl.sge32[0].phys_addr = ci_h;
        dcmd->sgl.sge32[0].length = sizeof(struct megasas_ctrl_info);

        if (!megasas_issue_polled(instance, cmd)) {
                ret = 0;
                memcpy(ctrl_info, ci, sizeof(struct megasas_ctrl_info));
        } else {
                ret = -1;
        }

        pci_free_consistent(instance->pdev, sizeof(struct megasas_ctrl_info),
                            ci, ci_h);

        megasas_return_cmd(instance, cmd);
        return ret;
}

/**
 * megasas_issue_init_mfi -     Initializes the FW
 * @instance:           Adapter soft state
 *
 * Issues the INIT MFI cmd
 */
static int
megasas_issue_init_mfi(struct megasas_instance *instance)
{
        u32 context;

        struct megasas_cmd *cmd;

        struct megasas_init_frame *init_frame;
        struct megasas_init_queue_info *initq_info;
        dma_addr_t init_frame_h;
        dma_addr_t initq_info_h;

        /*
         * Prepare a init frame. Note the init frame points to queue info
         * structure. Each frame has SGL allocated after first 64 bytes. For
         * this frame - since we don't need any SGL - we use SGL's space as
         * queue info structure
         *
         * We will not get a NULL command below. We just created the pool.
         */
        cmd = megasas_get_cmd(instance);

        init_frame = (struct megasas_init_frame *)cmd->frame;
        initq_info = (struct megasas_init_queue_info *)
                ((unsigned long)init_frame + 64);

        init_frame_h = cmd->frame_phys_addr;
        initq_info_h = init_frame_h + 64;

        context = init_frame->context;
        memset(init_frame, 0, MEGAMFI_FRAME_SIZE);
        memset(initq_info, 0, sizeof(struct megasas_init_queue_info));
        init_frame->context = context;

        initq_info->reply_queue_entries = instance->max_fw_cmds + 1;
        initq_info->reply_queue_start_phys_addr_lo = instance->reply_queue_h;

        initq_info->producer_index_phys_addr_lo = instance->producer_h;
        initq_info->consumer_index_phys_addr_lo = instance->consumer_h;

        init_frame->cmd = MFI_CMD_INIT;
        init_frame->cmd_status = 0xFF;
        init_frame->queue_info_new_phys_addr_lo = initq_info_h;

        init_frame->data_xfer_len = sizeof(struct megasas_init_queue_info);

        /*
         * disable the intr before firing the init frame to FW
         */
        instance->instancet->disable_intr(instance->reg_set);

        /*
         * Issue the init frame in polled mode
         */

        if (megasas_issue_polled(instance, cmd)) {
                printk(KERN_ERR "megasas: Failed to init firmware\n");
                megasas_return_cmd(instance, cmd);
                goto fail_fw_init;
        }

        megasas_return_cmd(instance, cmd);

        return 0;

fail_fw_init:
        return -EINVAL;
}

/**
 * megasas_start_timer - Initializes a timer object
 * @instance:           Adapter soft state
 * @timer:              timer object to be initialized
 * @fn:                 timer function
 * @interval:           time interval between timer function call
 */
static inline void
megasas_start_timer(struct megasas_instance *instance,
                        struct timer_list *timer,
                        void *fn, unsigned long interval)
{
        init_timer(timer);
        timer->expires = jiffies + interval;
        timer->data = (unsigned long)instance;
        timer->function = fn;
        add_timer(timer);
}

/**
 * megasas_io_completion_timer - Timer fn
 * @instance_addr:      Address of adapter soft state
 *
 * Schedules tasklet for cmd completion
 * if poll_mode_io is set
 */
static void
megasas_io_completion_timer(unsigned long instance_addr)
{
        struct megasas_instance *instance =
                        (struct megasas_instance *)instance_addr;

        if (atomic_read(&instance->fw_outstanding))
                tasklet_schedule(&instance->isr_tasklet);

        /* Restart timer */
        if (poll_mode_io)
                mod_timer(&instance->io_completion_timer,
                        jiffies + MEGASAS_COMPLETION_TIMER_INTERVAL);
}

/**
 * megasas_init_mfi -   Initializes the FW
 * @instance:           Adapter soft state
 *
 * This is the main function for initializing MFI firmware.
 */
static int megasas_init_mfi(struct megasas_instance *instance)
{
        u32 context_sz;
        u32 reply_q_sz;
        u32 max_sectors_1;
        u32 max_sectors_2;
        u32 tmp_sectors;
        struct megasas_register_set __iomem *reg_set;
        struct megasas_ctrl_info *ctrl_info;
        /*
         * Map the message registers
         */
        if ((instance->pdev->device == PCI_DEVICE_ID_LSI_SAS1078GEN2) ||
                (instance->pdev->device == PCI_DEVICE_ID_LSI_SAS0071SKINNY) ||
                (instance->pdev->device == PCI_DEVICE_ID_LSI_SAS0073SKINNY) ||
                (instance->pdev->device == PCI_DEVICE_ID_LSI_SAS0079GEN2)) {
                instance->base_addr = pci_resource_start(instance->pdev, 1);
        } else {
                instance->base_addr = pci_resource_start(instance->pdev, 0);
        }

        if (pci_request_selected_regions(instance->pdev,
                pci_select_bars(instance->pdev, IORESOURCE_MEM),
                "megasas: LSI")) {
                printk(KERN_DEBUG "megasas: IO memory region busy!\n");
                return -EBUSY;
        }

        instance->reg_set = ioremap_nocache(instance->base_addr, 8192);

        if (!instance->reg_set) {
                printk(KERN_DEBUG "megasas: Failed to map IO mem\n");
                goto fail_ioremap;
        }

        reg_set = instance->reg_set;

        switch(instance->pdev->device)
        {
                case PCI_DEVICE_ID_LSI_SAS1078R:
                case PCI_DEVICE_ID_LSI_SAS1078DE:
                        instance->instancet = &megasas_instance_template_ppc;
                        break;
                case PCI_DEVICE_ID_LSI_SAS1078GEN2:
                case PCI_DEVICE_ID_LSI_SAS0079GEN2:
                        instance->instancet = &megasas_instance_template_gen2;
                        break;
                case PCI_DEVICE_ID_LSI_SAS0073SKINNY:
                case PCI_DEVICE_ID_LSI_SAS0071SKINNY:
                        instance->instancet = &megasas_instance_template_skinny;
                        break;
                case PCI_DEVICE_ID_LSI_SAS1064R:
                case PCI_DEVICE_ID_DELL_PERC5:
                default:
                        instance->instancet = &megasas_instance_template_xscale;
                        break;
        }

        /*
         * We expect the FW state to be READY
         */
        if (megasas_transition_to_ready(instance))
                goto fail_ready_state;

        /*
         * Get various operational parameters from status register
         */
        instance->max_fw_cmds = instance->instancet->read_fw_status_reg(reg_set) & 0x00FFFF;
        /*
         * Reduce the max supported cmds by 1. This is to ensure that the
         * reply_q_sz (1 more than the max cmd that driver may send)
         * does not exceed max cmds that the FW can support
         */
        instance->max_fw_cmds = instance->max_fw_cmds-1;
        instance->max_num_sge = (instance->instancet->read_fw_status_reg(reg_set) & 0xFF0000) >> 
                                        0x10;
        /*
         * Create a pool of commands
         */
        if (megasas_alloc_cmds(instance))
                goto fail_alloc_cmds;

        /*
         * Allocate memory for reply queue. Length of reply queue should
         * be _one_ more than the maximum commands handled by the firmware.
         *
         * Note: When FW completes commands, it places corresponding contex
         * values in this circular reply queue. This circular queue is a fairly
         * typical producer-consumer queue. FW is the producer (of completed
         * commands) and the driver is the consumer.
         */
        context_sz = sizeof(u32);
        reply_q_sz = context_sz * (instance->max_fw_cmds + 1);

        instance->reply_queue = pci_alloc_consistent(instance->pdev,
                                                     reply_q_sz,
                                                     &instance->reply_queue_h);

        if (!instance->reply_queue) {
                printk(KERN_DEBUG "megasas: Out of DMA mem for reply queue\n");
                goto fail_reply_queue;
        }

        if (megasas_issue_init_mfi(instance))
                goto fail_fw_init;

        memset(instance->pd_list, 0 ,
                (MEGASAS_MAX_PD * sizeof(struct megasas_pd_list)));
        megasas_get_pd_list(instance);

        memset(instance->ld_ids, 0xff, MEGASAS_MAX_LD_IDS);
        megasas_get_ld_list(instance);

        ctrl_info = kmalloc(sizeof(struct megasas_ctrl_info), GFP_KERNEL);

        /*
         * Compute the max allowed sectors per IO: The controller info has two
         * limits on max sectors. Driver should use the minimum of these two.
         *
         * 1 << stripe_sz_ops.min = max sectors per strip
         *
         * Note that older firmwares ( < FW ver 30) didn't report information
         * to calculate max_sectors_1. So the number ended up as zero always.
         */
        tmp_sectors = 0;
        if (ctrl_info && !megasas_get_ctrl_info(instance, ctrl_info)) {

                max_sectors_1 = (1 << ctrl_info->stripe_sz_ops.min) *
                    ctrl_info->max_strips_per_io;
                max_sectors_2 = ctrl_info->max_request_size;

                tmp_sectors = min_t(u32, max_sectors_1 , max_sectors_2);
        }

        instance->max_sectors_per_req = instance->max_num_sge *
                                                PAGE_SIZE / 512;
        if (tmp_sectors && (instance->max_sectors_per_req > tmp_sectors))
                instance->max_sectors_per_req = tmp_sectors;

        kfree(ctrl_info);

        /*
        * Setup tasklet for cmd completion
        */

        tasklet_init(&instance->isr_tasklet, megasas_complete_cmd_dpc,
                (unsigned long)instance);

        /* Initialize the cmd completion timer */
        if (poll_mode_io)
                megasas_start_timer(instance, &instance->io_completion_timer,
                                megasas_io_completion_timer,
                                MEGASAS_COMPLETION_TIMER_INTERVAL);
        return 0;

      fail_fw_init:

        pci_free_consistent(instance->pdev, reply_q_sz,
                            instance->reply_queue, instance->reply_queue_h);
      fail_reply_queue:
        megasas_free_cmds(instance);

      fail_alloc_cmds:
      fail_ready_state:
        iounmap(instance->reg_set);

      fail_ioremap:
        pci_release_selected_regions(instance->pdev,
                pci_select_bars(instance->pdev, IORESOURCE_MEM));

        return -EINVAL;
}

/**
 * megasas_release_mfi -        Reverses the FW initialization
 * @intance:                    Adapter soft state
 */
static void megasas_release_mfi(struct megasas_instance *instance)
{
        u32 reply_q_sz = sizeof(u32) * (instance->max_fw_cmds + 1);

        pci_free_consistent(instance->pdev, reply_q_sz,
                            instance->reply_queue, instance->reply_queue_h);

        megasas_free_cmds(instance);

        iounmap(instance->reg_set);

        pci_release_selected_regions(instance->pdev,
                pci_select_bars(instance->pdev, IORESOURCE_MEM));
}

/**
 * megasas_get_seq_num -        Gets latest event sequence numbers
 * @instance:                   Adapter soft state
 * @eli:                        FW event log sequence numbers information
 *
 * FW maintains a log of all events in a non-volatile area. Upper layers would
 * usually find out the latest sequence number of the events, the seq number at
 * the boot etc. They would "read" all the events below the latest seq number
 * by issuing a direct fw cmd (DCMD). For the future events (beyond latest seq
 * number), they would subsribe to AEN (asynchronous event notification) and
 * wait for the events to happen.
 */
static int
megasas_get_seq_num(struct megasas_instance *instance,
                    struct megasas_evt_log_info *eli)
{
        struct megasas_cmd *cmd;
        struct megasas_dcmd_frame *dcmd;
        struct megasas_evt_log_info *el_info;
        dma_addr_t el_info_h = 0;

        cmd = megasas_get_cmd(instance);

        if (!cmd) {
                return -ENOMEM;
        }

        dcmd = &cmd->frame->dcmd;
        el_info = pci_alloc_consistent(instance->pdev,
                                       sizeof(struct megasas_evt_log_info),
                                       &el_info_h);

        if (!el_info) {
                megasas_return_cmd(instance, cmd);
                return -ENOMEM;
        }

        memset(el_info, 0, sizeof(*el_info));
        memset(dcmd->mbox.b, 0, MFI_MBOX_SIZE);

        dcmd->cmd = MFI_CMD_DCMD;
        dcmd->cmd_status = 0x0;
        dcmd->sge_count = 1;
        dcmd->flags = MFI_FRAME_DIR_READ;
        dcmd->timeout = 0;
        dcmd->pad_0 = 0;
        dcmd->data_xfer_len = sizeof(struct megasas_evt_log_info);
        dcmd->opcode = MR_DCMD_CTRL_EVENT_GET_INFO;
        dcmd->sgl.sge32[0].phys_addr = el_info_h;
        dcmd->sgl.sge32[0].length = sizeof(struct megasas_evt_log_info);

        megasas_issue_blocked_cmd(instance, cmd);

        /*
         * Copy the data back into callers buffer
         */
        memcpy(eli, el_info, sizeof(struct megasas_evt_log_info));

        pci_free_consistent(instance->pdev, sizeof(struct megasas_evt_log_info),
                            el_info, el_info_h);

        megasas_return_cmd(instance, cmd);

        return 0;
}

/**
 * megasas_register_aen -       Registers for asynchronous event notification
 * @instance:                   Adapter soft state
 * @seq_num:                    The starting sequence number
 * @class_locale:               Class of the event
 *
 * This function subscribes for AEN for events beyond the @seq_num. It requests
 * to be notified if and only if the event is of type @class_locale
 */
static int
megasas_register_aen(struct megasas_instance *instance, u32 seq_num,
                     u32 class_locale_word)
{
        int ret_val;
        struct megasas_cmd *cmd;
        struct megasas_dcmd_frame *dcmd;
        union megasas_evt_class_locale curr_aen;
        union megasas_evt_class_locale prev_aen;

        /*
         * If there an AEN pending already (aen_cmd), check if the
         * class_locale of that pending AEN is inclusive of the new
         * AEN request we currently have. If it is, then we don't have
         * to do anything. In other words, whichever events the current
         * AEN request is subscribing to, have already been subscribed
         * to.
         *
         * If the old_cmd is _not_ inclusive, then we have to abort
         * that command, form a class_locale that is superset of both
         * old and current and re-issue to the FW
         */

        curr_aen.word = class_locale_word;

        if (instance->aen_cmd) {

                prev_aen.word = instance->aen_cmd->frame->dcmd.mbox.w[1];

                /*
                 * A class whose enum value is smaller is inclusive of all
                 * higher values. If a PROGRESS (= -1) was previously
                 * registered, then a new registration requests for higher
                 * classes need not be sent to FW. They are automatically
                 * included.
                 *
                 * Locale numbers don't have such hierarchy. They are bitmap
                 * values
                 */
                if ((prev_aen.members.class <= curr_aen.members.class) &&
                    !((prev_aen.members.locale & curr_aen.members.locale) ^
                      curr_aen.members.locale)) {
                        /*
                         * Previously issued event registration includes
                         * current request. Nothing to do.
                         */
                        return 0;
                } else {
                        curr_aen.members.locale |= prev_aen.members.locale;

                        if (prev_aen.members.class < curr_aen.members.class)
                                curr_aen.members.class = prev_aen.members.class;

                        instance->aen_cmd->abort_aen = 1;
                        ret_val = megasas_issue_blocked_abort_cmd(instance,
                                                                  instance->
                                                                  aen_cmd);

                        if (ret_val) {
                                printk(KERN_DEBUG "megasas: Failed to abort "
                                       "previous AEN command\n");
                                return ret_val;
                        }
                }
        }

        cmd = megasas_get_cmd(instance);

        if (!cmd)
                return -ENOMEM;

        dcmd = &cmd->frame->dcmd;

        memset(instance->evt_detail, 0, sizeof(struct megasas_evt_detail));

        /*
         * Prepare DCMD for aen registration
         */
        memset(dcmd->mbox.b, 0, MFI_MBOX_SIZE);

        dcmd->cmd = MFI_CMD_DCMD;
        dcmd->cmd_status = 0x0;
        dcmd->sge_count = 1;
        dcmd->flags = MFI_FRAME_DIR_READ;
        dcmd->timeout = 0;
        dcmd->pad_0 = 0;
        dcmd->data_xfer_len = sizeof(struct megasas_evt_detail);
        dcmd->opcode = MR_DCMD_CTRL_EVENT_WAIT;
        dcmd->mbox.w[0] = seq_num;
        dcmd->mbox.w[1] = curr_aen.word;
        dcmd->sgl.sge32[0].phys_addr = (u32) instance->evt_detail_h;
        dcmd->sgl.sge32[0].length = sizeof(struct megasas_evt_detail);

        if (instance->aen_cmd != NULL) {
                megasas_return_cmd(instance, cmd);
                return 0;
        }

        /*
         * Store reference to the cmd used to register for AEN. When an
         * application wants us to register for AEN, we have to abort this
         * cmd and re-register with a new EVENT LOCALE supplied by that app
         */
        instance->aen_cmd = cmd;

        /*
         * Issue the aen registration frame
         */
        instance->instancet->fire_cmd(instance,
                        cmd->frame_phys_addr, 0, instance->reg_set);

        return 0;
}

/**
 * megasas_start_aen -  Subscribes to AEN during driver load time
 * @instance:           Adapter soft state
 */
static int megasas_start_aen(struct megasas_instance *instance)
{
        struct megasas_evt_log_info eli;
        union megasas_evt_class_locale class_locale;

        /*
         * Get the latest sequence number from FW
         */
        memset(&eli, 0, sizeof(eli));

        if (megasas_get_seq_num(instance, &eli))
                return -1;

        /*
         * Register AEN with FW for latest sequence number plus 1
         */
        class_locale.members.reserved = 0;
        class_locale.members.locale = MR_EVT_LOCALE_ALL;
        class_locale.members.class = MR_EVT_CLASS_DEBUG;

        return megasas_register_aen(instance, eli.newest_seq_num + 1,
                                    class_locale.word);
}

/**
 * megasas_io_attach -  Attaches this driver to SCSI mid-layer
 * @instance:           Adapter soft state
 */
static int megasas_io_attach(struct megasas_instance *instance)
{
        struct Scsi_Host *host = instance->host;

        /*
         * Export parameters required by SCSI mid-layer
         */
        host->irq = instance->pdev->irq;
        host->unique_id = instance->unique_id;