root/drivers/scsi/megaraid/megaraid_sas_fp.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Linux MegaRAID driver for SAS based RAID controllers
 *
 *  Copyright (c) 2009-2013  LSI Corporation
 *  Copyright (c) 2013-2016  Avago Technologies
 *  Copyright (c) 2016-2018  Broadcom Inc.
 *
 *  FILE: megaraid_sas_fp.c
 *
 *  Authors: Broadcom Inc.
 *           Sumant Patro
 *           Varad Talamacki
 *           Manoj Jose
 *           Kashyap Desai <kashyap.desai@broadcom.com>
 *           Sumit Saxena <sumit.saxena@broadcom.com>
 *
 *  Send feedback to: megaraidlinux.pdl@broadcom.com
 */

#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/uio.h>
#include <linux/uaccess.h>
#include <linux/fs.h>
#include <linux/compat.h>
#include <linux/blkdev.h>
#include <linux/poll.h>
#include <linux/irq_poll.h>

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

#include "megaraid_sas_fusion.h"
#include "megaraid_sas.h"
#include <asm/div64.h>

#define LB_PENDING_CMDS_DEFAULT 4
static unsigned int lb_pending_cmds = LB_PENDING_CMDS_DEFAULT;
module_param(lb_pending_cmds, int, 0444);
MODULE_PARM_DESC(lb_pending_cmds, "Change raid-1 load balancing outstanding "
        "threshold. Valid Values are 1-128. Default: 4");


#define ABS_DIFF(a, b)   (((a) > (b)) ? ((a) - (b)) : ((b) - (a)))
#define MR_LD_STATE_OPTIMAL 3

#define SPAN_ROW_SIZE(map, ld, index_) (MR_LdSpanPtrGet(ld, index_, map)->spanRowSize)
#define SPAN_ROW_DATA_SIZE(map_, ld, index_)   (MR_LdSpanPtrGet(ld, index_, map)->spanRowDataSize)
#define SPAN_INVALID  0xff

/* Prototypes */
static void mr_update_span_set(struct MR_DRV_RAID_MAP_ALL *map,
        PLD_SPAN_INFO ldSpanInfo);
static u8 mr_spanset_get_phy_params(struct megasas_instance *instance, u32 ld,
        u64 stripRow, u16 stripRef, struct IO_REQUEST_INFO *io_info,
        struct RAID_CONTEXT *pRAID_Context, struct MR_DRV_RAID_MAP_ALL *map);
static u64 get_row_from_strip(struct megasas_instance *instance, u32 ld,
        u64 strip, struct MR_DRV_RAID_MAP_ALL *map);

u32 mega_mod64(u64 dividend, u32 divisor)
{
        u64 d;
        u32 remainder;

        if (!divisor)
                printk(KERN_ERR "megasas : DIVISOR is zero, in div fn\n");
        d = dividend;
        remainder = do_div(d, divisor);
        return remainder;
}

/**
 * mega_div64_32 - Do a 64-bit division
 * @dividend:   Dividend
 * @divisor:    Divisor
 *
 * @return quotient
 **/
static u64 mega_div64_32(uint64_t dividend, uint32_t divisor)
{
        u64 d = dividend;

        if (!divisor)
                printk(KERN_ERR "megasas : DIVISOR is zero in mod fn\n");

        do_div(d, divisor);

        return d;
}

struct MR_LD_RAID *MR_LdRaidGet(u32 ld, struct MR_DRV_RAID_MAP_ALL *map)
{
        return &map->raidMap.ldSpanMap[ld].ldRaid;
}

static struct MR_SPAN_BLOCK_INFO *MR_LdSpanInfoGet(u32 ld,
                                                   struct MR_DRV_RAID_MAP_ALL
                                                   *map)
{
        return &map->raidMap.ldSpanMap[ld].spanBlock[0];
}

static u8 MR_LdDataArmGet(u32 ld, u32 armIdx, struct MR_DRV_RAID_MAP_ALL *map)
{
        return map->raidMap.ldSpanMap[ld].dataArmMap[armIdx];
}

u16 MR_ArPdGet(u32 ar, u32 arm, struct MR_DRV_RAID_MAP_ALL *map)
{
        return le16_to_cpu(map->raidMap.arMapInfo[ar].pd[arm]);
}

u16 MR_LdSpanArrayGet(u32 ld, u32 span, struct MR_DRV_RAID_MAP_ALL *map)
{
        return le16_to_cpu(map->raidMap.ldSpanMap[ld].spanBlock[span].span.arrayRef);
}

__le16 MR_PdDevHandleGet(u32 pd, struct MR_DRV_RAID_MAP_ALL *map)
{
        return map->raidMap.devHndlInfo[pd].curDevHdl;
}

static u8 MR_PdInterfaceTypeGet(u32 pd, struct MR_DRV_RAID_MAP_ALL *map)
{
        return map->raidMap.devHndlInfo[pd].interfaceType;
}

u16 MR_GetLDTgtId(u32 ld, struct MR_DRV_RAID_MAP_ALL *map)
{
        return le16_to_cpu(map->raidMap.ldSpanMap[ld].ldRaid.targetId);
}

u16 MR_TargetIdToLdGet(u32 ldTgtId, struct MR_DRV_RAID_MAP_ALL *map)
{
        return map->raidMap.ldTgtIdToLd[ldTgtId];
}

static struct MR_LD_SPAN *MR_LdSpanPtrGet(u32 ld, u32 span,
                                          struct MR_DRV_RAID_MAP_ALL *map)
{
        return &map->raidMap.ldSpanMap[ld].spanBlock[span].span;
}

/*
 * This function will Populate Driver Map using firmware raid map
 */
static int MR_PopulateDrvRaidMap(struct megasas_instance *instance, u64 map_id)
{
        struct fusion_context *fusion = instance->ctrl_context;
        struct MR_FW_RAID_MAP_ALL     *fw_map_old    = NULL;
        struct MR_FW_RAID_MAP         *pFwRaidMap    = NULL;
        int i, j;
        u16 ld_count;
        struct MR_FW_RAID_MAP_DYNAMIC *fw_map_dyn;
        struct MR_FW_RAID_MAP_EXT *fw_map_ext;
        struct MR_RAID_MAP_DESC_TABLE *desc_table;


        struct MR_DRV_RAID_MAP_ALL *drv_map =
                        fusion->ld_drv_map[(map_id & 1)];
        struct MR_DRV_RAID_MAP *pDrvRaidMap = &drv_map->raidMap;
        void *raid_map_data = NULL;

        memset(drv_map, 0, fusion->drv_map_sz);
        memset(pDrvRaidMap->ldTgtIdToLd,
               0xff, (sizeof(u16) * MAX_LOGICAL_DRIVES_DYN));

        if (instance->max_raid_mapsize) {
                fw_map_dyn = fusion->ld_map[(map_id & 1)];
                desc_table =
                (struct MR_RAID_MAP_DESC_TABLE *)((void *)fw_map_dyn + le32_to_cpu(fw_map_dyn->desc_table_offset));
                if (desc_table != fw_map_dyn->raid_map_desc_table)
                        dev_dbg(&instance->pdev->dev, "offsets of desc table are not matching desc %p original %p\n",
                                desc_table, fw_map_dyn->raid_map_desc_table);

                ld_count = (u16)le16_to_cpu(fw_map_dyn->ld_count);
                pDrvRaidMap->ldCount = (__le16)cpu_to_le16(ld_count);
                pDrvRaidMap->fpPdIoTimeoutSec =
                        fw_map_dyn->fp_pd_io_timeout_sec;
                pDrvRaidMap->totalSize =
                        cpu_to_le32(sizeof(struct MR_DRV_RAID_MAP_ALL));
                /* point to actual data starting point*/
                raid_map_data = (void *)fw_map_dyn +
                        le32_to_cpu(fw_map_dyn->desc_table_offset) +
                        le32_to_cpu(fw_map_dyn->desc_table_size);

                for (i = 0; i < le32_to_cpu(fw_map_dyn->desc_table_num_elements); ++i) {
                        switch (le32_to_cpu(desc_table->raid_map_desc_type)) {
                        case RAID_MAP_DESC_TYPE_DEVHDL_INFO:
                                fw_map_dyn->dev_hndl_info =
                                (struct MR_DEV_HANDLE_INFO *)(raid_map_data + le32_to_cpu(desc_table->raid_map_desc_offset));
                                memcpy(pDrvRaidMap->devHndlInfo,
                                        fw_map_dyn->dev_hndl_info,
                                        sizeof(struct MR_DEV_HANDLE_INFO) *
                                        le32_to_cpu(desc_table->raid_map_desc_elements));
                        break;
                        case RAID_MAP_DESC_TYPE_TGTID_INFO:
                                fw_map_dyn->ld_tgt_id_to_ld =
                                        (u16 *)(raid_map_data +
                                        le32_to_cpu(desc_table->raid_map_desc_offset));
                                for (j = 0; j < le32_to_cpu(desc_table->raid_map_desc_elements); j++) {
                                        pDrvRaidMap->ldTgtIdToLd[j] =
                                                le16_to_cpu(fw_map_dyn->ld_tgt_id_to_ld[j]);
                                }
                        break;
                        case RAID_MAP_DESC_TYPE_ARRAY_INFO:
                                fw_map_dyn->ar_map_info =
                                        (struct MR_ARRAY_INFO *)
                                        (raid_map_data + le32_to_cpu(desc_table->raid_map_desc_offset));
                                memcpy(pDrvRaidMap->arMapInfo,
                                       fw_map_dyn->ar_map_info,
                                       sizeof(struct MR_ARRAY_INFO) *
                                       le32_to_cpu(desc_table->raid_map_desc_elements));
                        break;
                        case RAID_MAP_DESC_TYPE_SPAN_INFO:
                                fw_map_dyn->ld_span_map =
                                        (struct MR_LD_SPAN_MAP *)
                                        (raid_map_data +
                                        le32_to_cpu(desc_table->raid_map_desc_offset));
                                memcpy(pDrvRaidMap->ldSpanMap,
                                       fw_map_dyn->ld_span_map,
                                       sizeof(struct MR_LD_SPAN_MAP) *
                                       le32_to_cpu(desc_table->raid_map_desc_elements));
                        break;
                        default:
                                dev_dbg(&instance->pdev->dev, "wrong number of desctableElements %d\n",
                                        fw_map_dyn->desc_table_num_elements);
                        }
                        ++desc_table;
                }

        } else if (instance->supportmax256vd) {
                fw_map_ext =
                        (struct MR_FW_RAID_MAP_EXT *)fusion->ld_map[(map_id & 1)];
                ld_count = (u16)le16_to_cpu(fw_map_ext->ldCount);
                if (ld_count > MAX_LOGICAL_DRIVES_EXT) {
                        dev_dbg(&instance->pdev->dev, "megaraid_sas: LD count exposed in RAID map in not valid\n");
                        return 1;
                }

                pDrvRaidMap->ldCount = (__le16)cpu_to_le16(ld_count);
                pDrvRaidMap->fpPdIoTimeoutSec = fw_map_ext->fpPdIoTimeoutSec;
                for (i = 0; i < (MAX_LOGICAL_DRIVES_EXT); i++)
                        pDrvRaidMap->ldTgtIdToLd[i] =
                                (u16)fw_map_ext->ldTgtIdToLd[i];
                memcpy(pDrvRaidMap->ldSpanMap, fw_map_ext->ldSpanMap,
                       sizeof(struct MR_LD_SPAN_MAP) * ld_count);
                memcpy(pDrvRaidMap->arMapInfo, fw_map_ext->arMapInfo,
                       sizeof(struct MR_ARRAY_INFO) * MAX_API_ARRAYS_EXT);
                memcpy(pDrvRaidMap->devHndlInfo, fw_map_ext->devHndlInfo,
                       sizeof(struct MR_DEV_HANDLE_INFO) *
                       MAX_RAIDMAP_PHYSICAL_DEVICES);

                /* New Raid map will not set totalSize, so keep expected value
                 * for legacy code in ValidateMapInfo
                 */
                pDrvRaidMap->totalSize =
                        cpu_to_le32(sizeof(struct MR_FW_RAID_MAP_EXT));
        } else {
                fw_map_old = (struct MR_FW_RAID_MAP_ALL *)
                                fusion->ld_map[(map_id & 1)];
                pFwRaidMap = &fw_map_old->raidMap;
                ld_count = (u16)le32_to_cpu(pFwRaidMap->ldCount);
                if (ld_count > MAX_LOGICAL_DRIVES) {
                        dev_dbg(&instance->pdev->dev,
                                "LD count exposed in RAID map in not valid\n");
                        return 1;
                }

                pDrvRaidMap->totalSize = pFwRaidMap->totalSize;
                pDrvRaidMap->ldCount = (__le16)cpu_to_le16(ld_count);
                pDrvRaidMap->fpPdIoTimeoutSec = pFwRaidMap->fpPdIoTimeoutSec;
                for (i = 0; i < MAX_RAIDMAP_LOGICAL_DRIVES + MAX_RAIDMAP_VIEWS; i++)
                        pDrvRaidMap->ldTgtIdToLd[i] =
                                (u8)pFwRaidMap->ldTgtIdToLd[i];
                for (i = 0; i < ld_count; i++) {
                        pDrvRaidMap->ldSpanMap[i] = pFwRaidMap->ldSpanMap[i];
                }
                memcpy(pDrvRaidMap->arMapInfo, pFwRaidMap->arMapInfo,
                        sizeof(struct MR_ARRAY_INFO) * MAX_RAIDMAP_ARRAYS);
                memcpy(pDrvRaidMap->devHndlInfo, pFwRaidMap->devHndlInfo,
                        sizeof(struct MR_DEV_HANDLE_INFO) *
                        MAX_RAIDMAP_PHYSICAL_DEVICES);
        }

        return 0;
}

/*
 * This function will validate Map info data provided by FW
 */
u8 MR_ValidateMapInfo(struct megasas_instance *instance, u64 map_id)
{
        struct fusion_context *fusion;
        struct MR_DRV_RAID_MAP_ALL *drv_map;
        struct MR_DRV_RAID_MAP *pDrvRaidMap;
        struct LD_LOAD_BALANCE_INFO *lbInfo;
        PLD_SPAN_INFO ldSpanInfo;
        struct MR_LD_RAID         *raid;
        u16 num_lds, i;
        u16 ld;
        u32 expected_size;

        if (MR_PopulateDrvRaidMap(instance, map_id))
                return 0;

        fusion = instance->ctrl_context;
        drv_map = fusion->ld_drv_map[(map_id & 1)];
        pDrvRaidMap = &drv_map->raidMap;

        lbInfo = fusion->load_balance_info;
        ldSpanInfo = fusion->log_to_span;

        if (instance->max_raid_mapsize)
                expected_size = sizeof(struct MR_DRV_RAID_MAP_ALL);
        else if (instance->supportmax256vd)
                expected_size = sizeof(struct MR_FW_RAID_MAP_EXT);
        else
                expected_size = struct_size_t(struct MR_FW_RAID_MAP,
                                              ldSpanMap,
                                              le16_to_cpu(pDrvRaidMap->ldCount));

        if (le32_to_cpu(pDrvRaidMap->totalSize) != expected_size) {
                dev_dbg(&instance->pdev->dev, "megasas: map info structure size 0x%x",
                        le32_to_cpu(pDrvRaidMap->totalSize));
                dev_dbg(&instance->pdev->dev, "is not matching expected size 0x%x\n",
                        (unsigned int)expected_size);
                dev_err(&instance->pdev->dev, "megasas: span map %x, pDrvRaidMap->totalSize : %x\n",
                        (unsigned int)sizeof(struct MR_LD_SPAN_MAP),
                        le32_to_cpu(pDrvRaidMap->totalSize));
                return 0;
        }

        if (instance->UnevenSpanSupport)
                mr_update_span_set(drv_map, ldSpanInfo);

        if (lbInfo)
                mr_update_load_balance_params(drv_map, lbInfo);

        num_lds = le16_to_cpu(drv_map->raidMap.ldCount);

        memcpy(instance->ld_ids_prev,
               instance->ld_ids_from_raidmap,
               sizeof(instance->ld_ids_from_raidmap));
        memset(instance->ld_ids_from_raidmap, 0xff, MEGASAS_MAX_LD_IDS);
        /*Convert Raid capability values to CPU arch */
        for (i = 0; (num_lds > 0) && (i < MAX_LOGICAL_DRIVES_EXT); i++) {
                ld = MR_TargetIdToLdGet(i, drv_map);

                /* For non existing VDs, iterate to next VD*/
                if (ld >= MEGASAS_MAX_SUPPORTED_LD_IDS)
                        continue;

                raid = MR_LdRaidGet(ld, drv_map);
                le32_to_cpus((u32 *)&raid->capability);
                instance->ld_ids_from_raidmap[i] = i;
                num_lds--;
        }

        return 1;
}

static u32 MR_GetSpanBlock(u32 ld, u64 row, u64 *span_blk,
                    struct MR_DRV_RAID_MAP_ALL *map)
{
        struct MR_SPAN_BLOCK_INFO *pSpanBlock = MR_LdSpanInfoGet(ld, map);
        struct MR_QUAD_ELEMENT    *quad;
        struct MR_LD_RAID         *raid = MR_LdRaidGet(ld, map);
        u32                span, j;

        for (span = 0; span < raid->spanDepth; span++, pSpanBlock++) {

                for (j = 0; j < le32_to_cpu(pSpanBlock->block_span_info.noElements); j++) {
                        quad = &pSpanBlock->block_span_info.quad[j];

                        if (le32_to_cpu(quad->diff) == 0)
                                return SPAN_INVALID;
                        if (le64_to_cpu(quad->logStart) <= row && row <=
                                le64_to_cpu(quad->logEnd) && (mega_mod64(row - le64_to_cpu(quad->logStart),
                                le32_to_cpu(quad->diff))) == 0) {
                                if (span_blk != NULL) {
                                        u64  blk;
                                        blk =  mega_div64_32((row-le64_to_cpu(quad->logStart)), le32_to_cpu(quad->diff));

                                        blk = (blk + le64_to_cpu(quad->offsetInSpan)) << raid->stripeShift;
                                        *span_blk = blk;
                                }
                                return span;
                        }
                }
        }
        return SPAN_INVALID;
}

/*
******************************************************************************
*
* This routine calculates the Span block for given row using spanset.
*
* Inputs :
*    instance - HBA instance
*    ld   - Logical drive number
*    row        - Row number
*    map    - LD map
*
* Outputs :
*
*    span          - Span number
*    block         - Absolute Block number in the physical disk
*    div_error     - Devide error code.
*/

static u32 mr_spanset_get_span_block(struct megasas_instance *instance,
                u32 ld, u64 row, u64 *span_blk, struct MR_DRV_RAID_MAP_ALL *map)
{
        struct fusion_context *fusion = instance->ctrl_context;
        struct MR_LD_RAID         *raid = MR_LdRaidGet(ld, map);
        LD_SPAN_SET *span_set;
        struct MR_QUAD_ELEMENT    *quad;
        u32    span, info;
        PLD_SPAN_INFO ldSpanInfo = fusion->log_to_span;

        for (info = 0; info < MAX_QUAD_DEPTH; info++) {
                span_set = &(ldSpanInfo[ld].span_set[info]);

                if (span_set->span_row_data_width == 0)
                        break;

                if (row > span_set->data_row_end)
                        continue;

                for (span = 0; span < raid->spanDepth; span++)
                        if (le32_to_cpu(map->raidMap.ldSpanMap[ld].spanBlock[span].
                                block_span_info.noElements) >= info+1) {
                                quad = &map->raidMap.ldSpanMap[ld].
                                        spanBlock[span].
                                        block_span_info.quad[info];
                                if (le32_to_cpu(quad->diff) == 0)
                                        return SPAN_INVALID;
                                if (le64_to_cpu(quad->logStart) <= row  &&
                                        row <= le64_to_cpu(quad->logEnd)  &&
                                        (mega_mod64(row - le64_to_cpu(quad->logStart),
                                                le32_to_cpu(quad->diff))) == 0) {
                                        if (span_blk != NULL) {
                                                u64  blk;
                                                blk = mega_div64_32
                                                    ((row - le64_to_cpu(quad->logStart)),
                                                    le32_to_cpu(quad->diff));
                                                blk = (blk + le64_to_cpu(quad->offsetInSpan))
                                                         << raid->stripeShift;
                                                *span_blk = blk;
                                        }
                                        return span;
                                }
                        }
        }
        return SPAN_INVALID;
}

/*
******************************************************************************
*
* This routine calculates the row for given strip using spanset.
*
* Inputs :
*    instance - HBA instance
*    ld   - Logical drive number
*    Strip        - Strip
*    map    - LD map
*
* Outputs :
*
*    row         - row associated with strip
*/

static u64  get_row_from_strip(struct megasas_instance *instance,
        u32 ld, u64 strip, struct MR_DRV_RAID_MAP_ALL *map)
{
        struct fusion_context *fusion = instance->ctrl_context;
        struct MR_LD_RAID       *raid = MR_LdRaidGet(ld, map);
        LD_SPAN_SET     *span_set;
        PLD_SPAN_INFO   ldSpanInfo = fusion->log_to_span;
        u32             info, strip_offset, span, span_offset;
        u64             span_set_Strip, span_set_Row, retval;

        for (info = 0; info < MAX_QUAD_DEPTH; info++) {
                span_set = &(ldSpanInfo[ld].span_set[info]);

                if (span_set->span_row_data_width == 0)
                        break;
                if (strip > span_set->data_strip_end)
                        continue;

                span_set_Strip = strip - span_set->data_strip_start;
                strip_offset = mega_mod64(span_set_Strip,
                                span_set->span_row_data_width);
                span_set_Row = mega_div64_32(span_set_Strip,
                                span_set->span_row_data_width) * span_set->diff;
                for (span = 0, span_offset = 0; span < raid->spanDepth; span++)
                        if (le32_to_cpu(map->raidMap.ldSpanMap[ld].spanBlock[span].
                                block_span_info.noElements) >= info+1) {
                                if (strip_offset >=
                                        span_set->strip_offset[span])
                                        span_offset++;
                                else
                                        break;
                        }

                retval = (span_set->data_row_start + span_set_Row +
                                (span_offset - 1));
                return retval;
        }
        return -1LLU;
}


/*
******************************************************************************
*
* This routine calculates the Start Strip for given row using spanset.
*
* Inputs :
*    instance - HBA instance
*    ld   - Logical drive number
*    row        - Row number
*    map    - LD map
*
* Outputs :
*
*    Strip         - Start strip associated with row
*/

static u64 get_strip_from_row(struct megasas_instance *instance,
                u32 ld, u64 row, struct MR_DRV_RAID_MAP_ALL *map)
{
        struct fusion_context *fusion = instance->ctrl_context;
        struct MR_LD_RAID         *raid = MR_LdRaidGet(ld, map);
        LD_SPAN_SET *span_set;
        struct MR_QUAD_ELEMENT    *quad;
        PLD_SPAN_INFO ldSpanInfo = fusion->log_to_span;
        u32    span, info;
        u64  strip;

        for (info = 0; info < MAX_QUAD_DEPTH; info++) {
                span_set = &(ldSpanInfo[ld].span_set[info]);

                if (span_set->span_row_data_width == 0)
                        break;
                if (row > span_set->data_row_end)
                        continue;

                for (span = 0; span < raid->spanDepth; span++)
                        if (le32_to_cpu(map->raidMap.ldSpanMap[ld].spanBlock[span].
                                block_span_info.noElements) >= info+1) {
                                quad = &map->raidMap.ldSpanMap[ld].
                                        spanBlock[span].block_span_info.quad[info];
                                if (le64_to_cpu(quad->logStart) <= row  &&
                                        row <= le64_to_cpu(quad->logEnd)  &&
                                        mega_mod64((row - le64_to_cpu(quad->logStart)),
                                        le32_to_cpu(quad->diff)) == 0) {
                                        strip = mega_div64_32
                                                (((row - span_set->data_row_start)
                                                        - le64_to_cpu(quad->logStart)),
                                                        le32_to_cpu(quad->diff));
                                        strip *= span_set->span_row_data_width;
                                        strip += span_set->data_strip_start;
                                        strip += span_set->strip_offset[span];
                                        return strip;
                                }
                        }
        }
        dev_err(&instance->pdev->dev, "get_strip_from_row"
                "returns invalid strip for ld=%x, row=%lx\n",
                ld, (long unsigned int)row);
        return -1;
}

/*
******************************************************************************
*
* This routine calculates the Physical Arm for given strip using spanset.
*
* Inputs :
*    instance - HBA instance
*    ld   - Logical drive number
*    strip      - Strip
*    map    - LD map
*
* Outputs :
*
*    Phys Arm         - Phys Arm associated with strip
*/

static u32 get_arm_from_strip(struct megasas_instance *instance,
        u32 ld, u64 strip, struct MR_DRV_RAID_MAP_ALL *map)
{
        struct fusion_context *fusion = instance->ctrl_context;
        struct MR_LD_RAID         *raid = MR_LdRaidGet(ld, map);
        LD_SPAN_SET *span_set;
        PLD_SPAN_INFO ldSpanInfo = fusion->log_to_span;
        u32    info, strip_offset, span, span_offset, retval;

        for (info = 0 ; info < MAX_QUAD_DEPTH; info++) {
                span_set = &(ldSpanInfo[ld].span_set[info]);

                if (span_set->span_row_data_width == 0)
                        break;
                if (strip > span_set->data_strip_end)
                        continue;

                strip_offset = (uint)mega_mod64
                                ((strip - span_set->data_strip_start),
                                span_set->span_row_data_width);

                for (span = 0, span_offset = 0; span < raid->spanDepth; span++)
                        if (le32_to_cpu(map->raidMap.ldSpanMap[ld].spanBlock[span].
                                block_span_info.noElements) >= info+1) {
                                if (strip_offset >=
                                        span_set->strip_offset[span])
                                        span_offset =
                                                span_set->strip_offset[span];
                                else
                                        break;
                        }

                retval = (strip_offset - span_offset);
                return retval;
        }

        dev_err(&instance->pdev->dev, "get_arm_from_strip"
                "returns invalid arm for ld=%x strip=%lx\n",
                ld, (long unsigned int)strip);

        return -1;
}

/* This Function will return Phys arm */
static u8 get_arm(struct megasas_instance *instance, u32 ld, u8 span, u64 stripe,
                struct MR_DRV_RAID_MAP_ALL *map)
{
        struct MR_LD_RAID  *raid = MR_LdRaidGet(ld, map);
        /* Need to check correct default value */
        u32    arm = 0;

        switch (raid->level) {
        case 0:
        case 5:
        case 6:
                arm = mega_mod64(stripe, SPAN_ROW_SIZE(map, ld, span));
                break;
        case 1:
                /* start with logical arm */
                arm = get_arm_from_strip(instance, ld, stripe, map);
                if (arm != -1U)
                        arm *= 2;
                break;
        }

        return arm;
}


/*
******************************************************************************
*
* This routine calculates the arm, span and block for the specified stripe and
* reference in stripe using spanset
*
* Inputs :
*
*    ld   - Logical drive number
*    stripRow        - Stripe number
*    stripRef    - Reference in stripe
*
* Outputs :
*
*    span          - Span number
*    block         - Absolute Block number in the physical disk
*/
static u8 mr_spanset_get_phy_params(struct megasas_instance *instance, u32 ld,
                u64 stripRow, u16 stripRef, struct IO_REQUEST_INFO *io_info,
                struct RAID_CONTEXT *pRAID_Context,
                struct MR_DRV_RAID_MAP_ALL *map)
{
        struct MR_LD_RAID  *raid = MR_LdRaidGet(ld, map);
        u32     pd, arRef, r1_alt_pd;
        u8      physArm, span;
        u64     row;
        u8      retval = true;
        u64     *pdBlock = &io_info->pdBlock;
        __le16  *pDevHandle = &io_info->devHandle;
        u8      *pPdInterface = &io_info->pd_interface;
        u32     logArm, rowMod, armQ, arm;

        *pDevHandle = cpu_to_le16(MR_DEVHANDLE_INVALID);

        /*Get row and span from io_info for Uneven Span IO.*/
        row         = io_info->start_row;
        span        = io_info->start_span;


        if (raid->level == 6) {
                logArm = get_arm_from_strip(instance, ld, stripRow, map);
                if (logArm == -1U)
                        return false;
                rowMod = mega_mod64(row, SPAN_ROW_SIZE(map, ld, span));
                armQ = SPAN_ROW_SIZE(map, ld, span) - 1 - rowMod;
                arm = armQ + 1 + logArm;
                if (arm >= SPAN_ROW_SIZE(map, ld, span))
                        arm -= SPAN_ROW_SIZE(map, ld, span);
                physArm = (u8)arm;
        } else
                /* Calculate the arm */
                physArm = get_arm(instance, ld, span, stripRow, map);
        if (physArm == 0xFF)
                return false;

        arRef       = MR_LdSpanArrayGet(ld, span, map);
        pd          = MR_ArPdGet(arRef, physArm, map);

        if (pd != MR_PD_INVALID) {
                *pDevHandle = MR_PdDevHandleGet(pd, map);
                *pPdInterface = MR_PdInterfaceTypeGet(pd, map);
                /* get second pd also for raid 1/10 fast path writes*/
                if ((instance->adapter_type >= VENTURA_SERIES) &&
                    (raid->level == 1) &&
                    !io_info->isRead) {
                        r1_alt_pd = MR_ArPdGet(arRef, physArm + 1, map);
                        if (r1_alt_pd != MR_PD_INVALID)
                                io_info->r1_alt_dev_handle =
                                MR_PdDevHandleGet(r1_alt_pd, map);
                }
        } else {
                if ((raid->level >= 5) &&
                        ((instance->adapter_type == THUNDERBOLT_SERIES)  ||
                        ((instance->adapter_type == INVADER_SERIES) &&
                        (raid->regTypeReqOnRead != REGION_TYPE_UNUSED))))
                        pRAID_Context->reg_lock_flags = REGION_TYPE_EXCLUSIVE;
                else if (raid->level == 1) {
                        physArm = physArm + 1;
                        pd = MR_ArPdGet(arRef, physArm, map);
                        if (pd != MR_PD_INVALID) {
                                *pDevHandle = MR_PdDevHandleGet(pd, map);
                                *pPdInterface = MR_PdInterfaceTypeGet(pd, map);
                        }
                }
        }

        *pdBlock += stripRef + le64_to_cpu(MR_LdSpanPtrGet(ld, span, map)->startBlk);
        if (instance->adapter_type >= VENTURA_SERIES) {
                ((struct RAID_CONTEXT_G35 *)pRAID_Context)->span_arm =
                        (span << RAID_CTX_SPANARM_SPAN_SHIFT) | physArm;
                io_info->span_arm =
                        (span << RAID_CTX_SPANARM_SPAN_SHIFT) | physArm;
        } else {
                pRAID_Context->span_arm =
                        (span << RAID_CTX_SPANARM_SPAN_SHIFT) | physArm;
                io_info->span_arm = pRAID_Context->span_arm;
        }
        io_info->pd_after_lb = pd;
        return retval;
}

/*
******************************************************************************
*
* This routine calculates the arm, span and block for the specified stripe and
* reference in stripe.
*
* Inputs :
*
*    ld   - Logical drive number
*    stripRow        - Stripe number
*    stripRef    - Reference in stripe
*
* Outputs :
*
*    span          - Span number
*    block         - Absolute Block number in the physical disk
*/
static u8 MR_GetPhyParams(struct megasas_instance *instance, u32 ld, u64 stripRow,
                u16 stripRef, struct IO_REQUEST_INFO *io_info,
                struct RAID_CONTEXT *pRAID_Context,
                struct MR_DRV_RAID_MAP_ALL *map)
{
        struct MR_LD_RAID  *raid = MR_LdRaidGet(ld, map);
        u32         pd, arRef, r1_alt_pd;
        u8          physArm, span;
        u64         row;
        u8          retval = true;
        u64         *pdBlock = &io_info->pdBlock;
        __le16      *pDevHandle = &io_info->devHandle;
        u8          *pPdInterface = &io_info->pd_interface;

        *pDevHandle = cpu_to_le16(MR_DEVHANDLE_INVALID);

        row =  mega_div64_32(stripRow, raid->rowDataSize);

        if (raid->level == 6) {
                /* logical arm within row */
                u32 logArm =  mega_mod64(stripRow, raid->rowDataSize);
                u32 rowMod, armQ, arm;

                if (raid->rowSize == 0)
                        return false;
                /* get logical row mod */
                rowMod = mega_mod64(row, raid->rowSize);
                armQ = raid->rowSize-1-rowMod; /* index of Q drive */
                arm = armQ+1+logArm; /* data always logically follows Q */
                if (arm >= raid->rowSize) /* handle wrap condition */
                        arm -= raid->rowSize;
                physArm = (u8)arm;
        } else  {
                if (raid->modFactor == 0)
                        return false;
                physArm = MR_LdDataArmGet(ld,  mega_mod64(stripRow,
                                                          raid->modFactor),
                                          map);
        }

        if (raid->spanDepth == 1) {
                span = 0;
                *pdBlock = row << raid->stripeShift;
        } else {
                span = (u8)MR_GetSpanBlock(ld, row, pdBlock, map);
                if (span == SPAN_INVALID)
                        return false;
        }

        /* Get the array on which this span is present */
        arRef       = MR_LdSpanArrayGet(ld, span, map);
        pd          = MR_ArPdGet(arRef, physArm, map); /* Get the pd */

        if (pd != MR_PD_INVALID) {
                /* Get dev handle from Pd. */
                *pDevHandle = MR_PdDevHandleGet(pd, map);
                *pPdInterface = MR_PdInterfaceTypeGet(pd, map);
                /* get second pd also for raid 1/10 fast path writes*/
                if ((instance->adapter_type >= VENTURA_SERIES) &&
                    (raid->level == 1) &&
                    !io_info->isRead) {
                        r1_alt_pd = MR_ArPdGet(arRef, physArm + 1, map);
                        if (r1_alt_pd != MR_PD_INVALID)
                                io_info->r1_alt_dev_handle =
                                        MR_PdDevHandleGet(r1_alt_pd, map);
                }
        } else {
                if ((raid->level >= 5) &&
                        ((instance->adapter_type == THUNDERBOLT_SERIES)  ||
                        ((instance->adapter_type == INVADER_SERIES) &&
                        (raid->regTypeReqOnRead != REGION_TYPE_UNUSED))))
                        pRAID_Context->reg_lock_flags = REGION_TYPE_EXCLUSIVE;
                else if (raid->level == 1) {
                        /* Get alternate Pd. */
                        physArm = physArm + 1;
                        pd = MR_ArPdGet(arRef, physArm, map);
                        if (pd != MR_PD_INVALID) {
                                /* Get dev handle from Pd */
                                *pDevHandle = MR_PdDevHandleGet(pd, map);
                                *pPdInterface = MR_PdInterfaceTypeGet(pd, map);
                        }
                }
        }

        *pdBlock += stripRef + le64_to_cpu(MR_LdSpanPtrGet(ld, span, map)->startBlk);
        if (instance->adapter_type >= VENTURA_SERIES) {
                ((struct RAID_CONTEXT_G35 *)pRAID_Context)->span_arm =
                                (span << RAID_CTX_SPANARM_SPAN_SHIFT) | physArm;
                io_info->span_arm =
                                (span << RAID_CTX_SPANARM_SPAN_SHIFT) | physArm;
        } else {
                pRAID_Context->span_arm =
                        (span << RAID_CTX_SPANARM_SPAN_SHIFT) | physArm;
                io_info->span_arm = pRAID_Context->span_arm;
        }
        io_info->pd_after_lb = pd;
        return retval;
}

/*
 * mr_get_phy_params_r56_rmw -  Calculate parameters for R56 CTIO write operation
 * @instance:                   Adapter soft state
 * @ld:                         LD index
 * @stripNo:                    Strip Number
 * @io_info:                    IO info structure pointer
 * pRAID_Context:               RAID context pointer
 * map:                         RAID map pointer
 *
 * This routine calculates the logical arm, data Arm, row number and parity arm
 * for R56 CTIO write operation.
 */
static void mr_get_phy_params_r56_rmw(struct megasas_instance *instance,
                            u32 ld, u64 stripNo,
                            struct IO_REQUEST_INFO *io_info,
                            struct RAID_CONTEXT_G35 *pRAID_Context,
                            struct MR_DRV_RAID_MAP_ALL *map)
{
        struct MR_LD_RAID  *raid = MR_LdRaidGet(ld, map);
        u8          span, dataArms, arms, dataArm, logArm;
        s8          rightmostParityArm, PParityArm;
        u64         rowNum;
        u64 *pdBlock = &io_info->pdBlock;

        dataArms = raid->rowDataSize;
        arms = raid->rowSize;

        rowNum =  mega_div64_32(stripNo, dataArms);
        /* parity disk arm, first arm is 0 */
        rightmostParityArm = (arms - 1) - mega_mod64(rowNum, arms);

        /* logical arm within row */
        logArm =  mega_mod64(stripNo, dataArms);
        /* physical arm for data */
        dataArm = mega_mod64((rightmostParityArm + 1 + logArm), arms);

        if (raid->spanDepth == 1) {
                span = 0;
        } else {
                span = (u8)MR_GetSpanBlock(ld, rowNum, pdBlock, map);
                if (span == SPAN_INVALID)
                        return;
        }

        if (raid->level == 6) {
                /* P Parity arm, note this can go negative adjust if negative */
                PParityArm = (arms - 2) - mega_mod64(rowNum, arms);

                if (PParityArm < 0)
                        PParityArm += arms;

                /* rightmostParityArm is P-Parity for RAID 5 and Q-Parity for RAID */
                pRAID_Context->flow_specific.r56_arm_map = rightmostParityArm;
                pRAID_Context->flow_specific.r56_arm_map |=
                                    (u16)(PParityArm << RAID_CTX_R56_P_ARM_SHIFT);
        } else {
                pRAID_Context->flow_specific.r56_arm_map |=
                                    (u16)(rightmostParityArm << RAID_CTX_R56_P_ARM_SHIFT);
        }

        pRAID_Context->reg_lock_row_lba = cpu_to_le64(rowNum);
        pRAID_Context->flow_specific.r56_arm_map |=
                                   (u16)(logArm << RAID_CTX_R56_LOG_ARM_SHIFT);
        cpu_to_le16s(&pRAID_Context->flow_specific.r56_arm_map);
        pRAID_Context->span_arm = (span << RAID_CTX_SPANARM_SPAN_SHIFT) | dataArm;
        pRAID_Context->raid_flags = (MR_RAID_FLAGS_IO_SUB_TYPE_R56_DIV_OFFLOAD <<
                                    MR_RAID_CTX_RAID_FLAGS_IO_SUB_TYPE_SHIFT);

        return;
}

/*
******************************************************************************
*
* MR_BuildRaidContext function
*
* This function will initiate command processing.  The start/end row and strip
* information is calculated then the lock is acquired.
* This function will return 0 if region lock was acquired OR return num strips
*/
u8
MR_BuildRaidContext(struct megasas_instance *instance,
                    struct IO_REQUEST_INFO *io_info,
                    struct RAID_CONTEXT *pRAID_Context,
                    struct MR_DRV_RAID_MAP_ALL *map, u8 **raidLUN)
{
        struct fusion_context *fusion;
        struct MR_LD_RAID  *raid;
        u32         stripSize, stripe_mask;
        u64         endLba, endStrip, endRow, start_row, start_strip;
        u64         regStart;
        u32         regSize;
        u8          num_strips, numRows;
        u16         ref_in_start_stripe, ref_in_end_stripe;
        u64         ldStartBlock;
        u32         numBlocks, ldTgtId;
        u8          isRead;
        u8          retval = 0;
        u8          startlba_span = SPAN_INVALID;
        u64 *pdBlock = &io_info->pdBlock;
        u16         ld;

        ldStartBlock = io_info->ldStartBlock;
        numBlocks = io_info->numBlocks;
        ldTgtId = io_info->ldTgtId;
        isRead = io_info->isRead;
        io_info->IoforUnevenSpan = 0;
        io_info->start_span     = SPAN_INVALID;
        fusion = instance->ctrl_context;

        ld = MR_TargetIdToLdGet(ldTgtId, map);
        raid = MR_LdRaidGet(ld, map);
        /*check read ahead bit*/
        io_info->ra_capable = raid->capability.ra_capable;

        /*
         * if rowDataSize @RAID map and spanRowDataSize @SPAN INFO are zero
         * return FALSE
         */
        if (raid->rowDataSize == 0) {
                if (MR_LdSpanPtrGet(ld, 0, map)->spanRowDataSize == 0)
                        return false;
                else if (instance->UnevenSpanSupport) {
                        io_info->IoforUnevenSpan = 1;
                } else {
                        dev_info(&instance->pdev->dev,
                                "raid->rowDataSize is 0, but has SPAN[0]"
                                "rowDataSize = 0x%0x,"
                                "but there is _NO_ UnevenSpanSupport\n",
                                MR_LdSpanPtrGet(ld, 0, map)->spanRowDataSize);
                        return false;
                }
        }

        stripSize = 1 << raid->stripeShift;
        stripe_mask = stripSize-1;

        io_info->data_arms = raid->rowDataSize;

        /*
         * calculate starting row and stripe, and number of strips and rows
         */
        start_strip         = ldStartBlock >> raid->stripeShift;
        ref_in_start_stripe = (u16)(ldStartBlock & stripe_mask);
        endLba              = ldStartBlock + numBlocks - 1;
        ref_in_end_stripe   = (u16)(endLba & stripe_mask);
        endStrip            = endLba >> raid->stripeShift;
        num_strips          = (u8)(endStrip - start_strip + 1); /* End strip */

        if (io_info->IoforUnevenSpan) {
                start_row = get_row_from_strip(instance, ld, start_strip, map);
                endRow    = get_row_from_strip(instance, ld, endStrip, map);
                if (start_row == -1ULL || endRow == -1ULL) {
                        dev_info(&instance->pdev->dev, "return from %s %d."
                                "Send IO w/o region lock.\n",
                                __func__, __LINE__);
                        return false;
                }

                if (raid->spanDepth == 1) {
                        startlba_span = 0;
                        *pdBlock = start_row << raid->stripeShift;
                } else
                        startlba_span = (u8)mr_spanset_get_span_block(instance,
                                                ld, start_row, pdBlock, map);
                if (startlba_span == SPAN_INVALID) {
                        dev_info(&instance->pdev->dev, "return from %s %d"
                                "for row 0x%llx,start strip %llx"
                                "endSrip %llx\n", __func__, __LINE__,
                                (unsigned long long)start_row,
                                (unsigned long long)start_strip,
                                (unsigned long long)endStrip);
                        return false;
                }
                io_info->start_span     = startlba_span;
                io_info->start_row      = start_row;
        } else {
                start_row = mega_div64_32(start_strip, raid->rowDataSize);
                endRow    = mega_div64_32(endStrip, raid->rowDataSize);
        }
        numRows = (u8)(endRow - start_row + 1);

        /*
         * calculate region info.
         */

        /* assume region is at the start of the first row */
        regStart            = start_row << raid->stripeShift;
        /* assume this IO needs the full row - we'll adjust if not true */
        regSize             = stripSize;

        io_info->do_fp_rlbypass = raid->capability.fpBypassRegionLock;

        /* Check if we can send this I/O via FastPath */
        if (raid->capability.fpCapable) {
                if (isRead)
                        io_info->fpOkForIo = (raid->capability.fpReadCapable &&
                                              ((num_strips == 1) ||
                                               raid->capability.
                                               fpReadAcrossStripe));
                else
                        io_info->fpOkForIo = (raid->capability.fpWriteCapable &&
                                              ((num_strips == 1) ||
                                               raid->capability.
                                               fpWriteAcrossStripe));
        } else
                io_info->fpOkForIo = false;

        if (numRows == 1) {
                /* single-strip IOs can always lock only the data needed */
                if (num_strips == 1) {
                        regStart += ref_in_start_stripe;
                        regSize = numBlocks;
                }
                /* multi-strip IOs always need to full stripe locked */
        } else if (io_info->IoforUnevenSpan == 0) {
                /*
                 * For Even span region lock optimization.
                 * If the start strip is the last in the start row
                 */
                if (start_strip == (start_row + 1) * raid->rowDataSize - 1) {
                        regStart += ref_in_start_stripe;
                        /* initialize count to sectors from startref to end
                           of strip */
                        regSize = stripSize - ref_in_start_stripe;
                }

                /* add complete rows in the middle of the transfer */
                if (numRows > 2)
                        regSize += (numRows-2) << raid->stripeShift;

                /* if IO ends within first strip of last row*/
                if (endStrip == endRow*raid->rowDataSize)
                        regSize += ref_in_end_stripe+1;
                else
                        regSize += stripSize;
        } else {
                /*
                 * For Uneven span region lock optimization.
                 * If the start strip is the last in the start row
                 */
                if (start_strip == (get_strip_from_row(instance, ld, start_row, map) +
                                SPAN_ROW_DATA_SIZE(map, ld, startlba_span) - 1)) {
                        regStart += ref_in_start_stripe;
                        /* initialize count to sectors from
                         * startRef to end of strip
                         */
                        regSize = stripSize - ref_in_start_stripe;
                }
                /* Add complete rows in the middle of the transfer*/

                if (numRows > 2)
                        /* Add complete rows in the middle of the transfer*/
                        regSize += (numRows-2) << raid->stripeShift;

                /* if IO ends within first strip of last row */
                if (endStrip == get_strip_from_row(instance, ld, endRow, map))
                        regSize += ref_in_end_stripe + 1;
                else
                        regSize += stripSize;
        }

        pRAID_Context->timeout_value =
                cpu_to_le16(raid->fpIoTimeoutForLd ?
                            raid->fpIoTimeoutForLd :
                            map->raidMap.fpPdIoTimeoutSec);
        if (instance->adapter_type == INVADER_SERIES)
                pRAID_Context->reg_lock_flags = (isRead) ?
                        raid->regTypeReqOnRead : raid->regTypeReqOnWrite;
        else if (instance->adapter_type == THUNDERBOLT_SERIES)
                pRAID_Context->reg_lock_flags = (isRead) ?
                        REGION_TYPE_SHARED_READ : raid->regTypeReqOnWrite;
        pRAID_Context->virtual_disk_tgt_id = raid->targetId;
        pRAID_Context->reg_lock_row_lba    = cpu_to_le64(regStart);
        pRAID_Context->reg_lock_length    = cpu_to_le32(regSize);
        pRAID_Context->config_seq_num   = raid->seqNum;
        /* save pointer to raid->LUN array */
        *raidLUN = raid->LUN;

        /* Aero R5/6 Division Offload for WRITE */
        if (fusion->r56_div_offload && (raid->level >= 5) && !isRead) {
                mr_get_phy_params_r56_rmw(instance, ld, start_strip, io_info,
                                       (struct RAID_CONTEXT_G35 *)pRAID_Context,
                                       map);
                return true;
        }

        /*Get Phy Params only if FP capable, or else leave it to MR firmware
          to do the calculation.*/
        if (io_info->fpOkForIo) {
                retval = io_info->IoforUnevenSpan ?
                                mr_spanset_get_phy_params(instance, ld,
                                        start_strip, ref_in_start_stripe,
                                        io_info, pRAID_Context, map) :
                                MR_GetPhyParams(instance, ld, start_strip,
                                        ref_in_start_stripe, io_info,
                                        pRAID_Context, map);
                /* If IO on an invalid Pd, then FP is not possible.*/
                if (io_info->devHandle == MR_DEVHANDLE_INVALID)
                        io_info->fpOkForIo = false;
                return retval;
        } else if (isRead) {
                uint stripIdx;
                for (stripIdx = 0; stripIdx < num_strips; stripIdx++) {
                        retval = io_info->IoforUnevenSpan ?
                                mr_spanset_get_phy_params(instance, ld,
                                    start_strip + stripIdx,
                                    ref_in_start_stripe, io_info,
                                    pRAID_Context, map) :
                                MR_GetPhyParams(instance, ld,
                                    start_strip + stripIdx, ref_in_start_stripe,
                                    io_info, pRAID_Context, map);
                        if (!retval)
                                return true;
                }
        }
        return true;
}

/*
******************************************************************************
*
* This routine pepare spanset info from Valid Raid map and store it into
* local copy of ldSpanInfo per instance data structure.
*
* Inputs :
* map    - LD map
* ldSpanInfo - ldSpanInfo per HBA instance
*
*/
void mr_update_span_set(struct MR_DRV_RAID_MAP_ALL *map,
        PLD_SPAN_INFO ldSpanInfo)
{
        u8   span, count;
        u32  element, span_row_width;
        u64  span_row;
        struct MR_LD_RAID *raid;
        LD_SPAN_SET *span_set, *span_set_prev;
        struct MR_QUAD_ELEMENT    *quad;
        int ldCount;
        u16 ld;


        for (ldCount = 0; ldCount < MAX_LOGICAL_DRIVES_EXT; ldCount++) {
                ld = MR_TargetIdToLdGet(ldCount, map);
                if (ld >= (MAX_LOGICAL_DRIVES_EXT - 1))
                        continue;
                raid = MR_LdRaidGet(ld, map);
                for (element = 0; element < MAX_QUAD_DEPTH; element++) {
                        for (span = 0; span < raid->spanDepth; span++) {
                                if (le32_to_cpu(map->raidMap.ldSpanMap[ld].spanBlock[span].
                                        block_span_info.noElements) <
                                        element + 1)
                                        continue;
                                span_set = &(ldSpanInfo[ld].span_set[element]);
                                quad = &map->raidMap.ldSpanMap[ld].
                                        spanBlock[span].block_span_info.
                                        quad[element];

                                span_set->diff = le32_to_cpu(quad->diff);

                                for (count = 0, span_row_width = 0;
                                        count < raid->spanDepth; count++) {
                                        if (le32_to_cpu(map->raidMap.ldSpanMap[ld].
                                                spanBlock[count].
                                                block_span_info.
                                                noElements) >= element + 1) {
                                                span_set->strip_offset[count] =
                                                        span_row_width;
                                                span_row_width +=
                                                        MR_LdSpanPtrGet
                                                        (ld, count, map)->spanRowDataSize;
                                        }
                                }

                                span_set->span_row_data_width = span_row_width;
                                span_row = mega_div64_32(((le64_to_cpu(quad->logEnd) -
                                        le64_to_cpu(quad->logStart)) + le32_to_cpu(quad->diff)),
                                        le32_to_cpu(quad->diff));

                                if (element == 0) {
                                        span_set->log_start_lba = 0;
                                        span_set->log_end_lba =
                                                ((span_row << raid->stripeShift)
                                                * span_row_width) - 1;

                                        span_set->span_row_start = 0;
                                        span_set->span_row_end = span_row - 1;

                                        span_set->data_strip_start = 0;
                                        span_set->data_strip_end =
                                                (span_row * span_row_width) - 1;

                                        span_set->data_row_start = 0;
                                        span_set->data_row_end =
                                                (span_row * le32_to_cpu(quad->diff)) - 1;
                                } else {
                                        span_set_prev = &(ldSpanInfo[ld].
                                                        span_set[element - 1]);
                                        span_set->log_start_lba =
                                                span_set_prev->log_end_lba + 1;
                                        span_set->log_end_lba =
                                                span_set->log_start_lba +
                                                ((span_row << raid->stripeShift)
                                                * span_row_width) - 1;

                                        span_set->span_row_start =
                                                span_set_prev->span_row_end + 1;
                                        span_set->span_row_end =
                                        span_set->span_row_start + span_row - 1;

                                        span_set->data_strip_start =
                                        span_set_prev->data_strip_end + 1;
                                        span_set->data_strip_end =
                                                span_set->data_strip_start +
                                                (span_row * span_row_width) - 1;

                                        span_set->data_row_start =
                                                span_set_prev->data_row_end + 1;
                                        span_set->data_row_end =
                                                span_set->data_row_start +
                                                (span_row * le32_to_cpu(quad->diff)) - 1;
                                }
                                break;
                }
                if (span == raid->spanDepth)
                        break;
            }
        }
}

void mr_update_load_balance_params(struct MR_DRV_RAID_MAP_ALL *drv_map,
        struct LD_LOAD_BALANCE_INFO *lbInfo)
{
        int ldCount;
        u16 ld;
        struct MR_LD_RAID *raid;

        if (lb_pending_cmds > 128 || lb_pending_cmds < 1)
                lb_pending_cmds = LB_PENDING_CMDS_DEFAULT;

        for (ldCount = 0; ldCount < MAX_LOGICAL_DRIVES_EXT; ldCount++) {
                ld = MR_TargetIdToLdGet(ldCount, drv_map);
                if (ld >= MAX_LOGICAL_DRIVES_EXT - 1) {
                        lbInfo[ldCount].loadBalanceFlag = 0;
                        continue;
                }

                raid = MR_LdRaidGet(ld, drv_map);
                if ((raid->level != 1) ||
                        (raid->ldState != MR_LD_STATE_OPTIMAL)) {
                        lbInfo[ldCount].loadBalanceFlag = 0;
                        continue;
                }
                lbInfo[ldCount].loadBalanceFlag = 1;
        }
}

static u8 megasas_get_best_arm_pd(struct megasas_instance *instance,
                           struct LD_LOAD_BALANCE_INFO *lbInfo,
                           struct IO_REQUEST_INFO *io_info,
                           struct MR_DRV_RAID_MAP_ALL *drv_map)
{
        struct MR_LD_RAID  *raid;
        u16     pd1_dev_handle;
        u16     pend0, pend1, ld;
        u64     diff0, diff1;
        u8      bestArm, pd0, pd1, span, arm;
        u32     arRef, span_row_size;

        u64 block = io_info->ldStartBlock;
        u32 count = io_info->numBlocks;

        span = ((io_info->span_arm & RAID_CTX_SPANARM_SPAN_MASK)
                        >> RAID_CTX_SPANARM_SPAN_SHIFT);
        arm = (io_info->span_arm & RAID_CTX_SPANARM_ARM_MASK);

        ld = MR_TargetIdToLdGet(io_info->ldTgtId, drv_map);
        raid = MR_LdRaidGet(ld, drv_map);
        span_row_size = instance->UnevenSpanSupport ?
                        SPAN_ROW_SIZE(drv_map, ld, span) : raid->rowSize;

        arRef = MR_LdSpanArrayGet(ld, span, drv_map);
        pd0 = MR_ArPdGet(arRef, arm, drv_map);
        pd1 = MR_ArPdGet(arRef, (arm + 1) >= span_row_size ?
                (arm + 1 - span_row_size) : arm + 1, drv_map);

        /* Get PD1 Dev Handle */

        pd1_dev_handle = MR_PdDevHandleGet(pd1, drv_map);

        if (pd1_dev_handle == MR_DEVHANDLE_INVALID) {
                bestArm = arm;
        } else {
                /* get the pending cmds for the data and mirror arms */
                pend0 = atomic_read(&lbInfo->scsi_pending_cmds[pd0]);
                pend1 = atomic_read(&lbInfo->scsi_pending_cmds[pd1]);

                /* Determine the disk whose head is nearer to the req. block */
                diff0 = ABS_DIFF(block, lbInfo->last_accessed_block[pd0]);
                diff1 = ABS_DIFF(block, lbInfo->last_accessed_block[pd1]);
                bestArm = (diff0 <= diff1 ? arm : arm ^ 1);

                /* Make balance count from 16 to 4 to
                 *  keep driver in sync with Firmware
                 */
                if ((bestArm == arm && pend0 > pend1 + lb_pending_cmds)  ||
                    (bestArm != arm && pend1 > pend0 + lb_pending_cmds))
                        bestArm ^= 1;

                /* Update the last accessed block on the correct pd */
                io_info->span_arm =
                        (span << RAID_CTX_SPANARM_SPAN_SHIFT) | bestArm;
                io_info->pd_after_lb = (bestArm == arm) ? pd0 : pd1;
        }

        lbInfo->last_accessed_block[io_info->pd_after_lb] = block + count - 1;
        return io_info->pd_after_lb;
}

__le16 get_updated_dev_handle(struct megasas_instance *instance,
                              struct LD_LOAD_BALANCE_INFO *lbInfo,
                              struct IO_REQUEST_INFO *io_info,
                              struct MR_DRV_RAID_MAP_ALL *drv_map)
{
        u8 arm_pd;
        __le16 devHandle;

        /* get best new arm (PD ID) */
        arm_pd  = megasas_get_best_arm_pd(instance, lbInfo, io_info, drv_map);
        devHandle = MR_PdDevHandleGet(arm_pd, drv_map);
        io_info->pd_interface = MR_PdInterfaceTypeGet(arm_pd, drv_map);
        atomic_inc(&lbInfo->scsi_pending_cmds[arm_pd]);

        return devHandle;
}