Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[mirror_ubuntu-artful-kernel.git] / drivers / scsi / ufs / ufshcd.c

/*
 * Universal Flash Storage Host controller driver Core
 *
 * This code is based on drivers/scsi/ufs/ufshcd.c
 * Copyright (C) 2011-2013 Samsung India Software Operations
 * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
 *
 * Authors:
 *      Santosh Yaraganavi <santosh.sy@samsung.com>
 *      Vinayak Holikatti <h.vinayak@samsung.com>
 *
 * 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.
 * See the COPYING file in the top-level directory or visit
 * <http://www.gnu.org/licenses/gpl-2.0.html>
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * This program is provided "AS IS" and "WITH ALL FAULTS" and
 * without warranty of any kind. You are solely responsible for
 * determining the appropriateness of using and distributing
 * the program and assume all risks associated with your exercise
 * of rights with respect to the program, including but not limited
 * to infringement of third party rights, the risks and costs of
 * program errors, damage to or loss of data, programs or equipment,
 * and unavailability or interruption of operations. Under no
 * circumstances will the contributor of this Program be liable for
 * any damages of any kind arising from your use or distribution of
 * this program.
 *
 * The Linux Foundation chooses to take subject only to the GPLv2
 * license terms, and distributes only under these terms.
 */

#include <linux/async.h>
#include <linux/devfreq.h>

#include "ufshcd.h"
#include "unipro.h"

#define UFSHCD_ENABLE_INTRS     (UTP_TRANSFER_REQ_COMPL |\
                                 UTP_TASK_REQ_COMPL |\
                                 UFSHCD_ERROR_MASK)
/* UIC command timeout, unit: ms */
#define UIC_CMD_TIMEOUT 500

/* NOP OUT retries waiting for NOP IN response */
#define NOP_OUT_RETRIES    10
/* Timeout after 30 msecs if NOP OUT hangs without response */
#define NOP_OUT_TIMEOUT    30 /* msecs */

/* Query request retries */
#define QUERY_REQ_RETRIES 10
/* Query request timeout */
#define QUERY_REQ_TIMEOUT 30 /* msec */

/* Task management command timeout */
#define TM_CMD_TIMEOUT  100 /* msecs */

/* maximum number of link-startup retries */
#define DME_LINKSTARTUP_RETRIES 3

/* maximum number of reset retries before giving up */
#define MAX_HOST_RESET_RETRIES 5

/* Expose the flag value from utp_upiu_query.value */
#define MASK_QUERY_UPIU_FLAG_LOC 0xFF

/* Interrupt aggregation default timeout, unit: 40us */
#define INT_AGGR_DEF_TO 0x02

#define ufshcd_toggle_vreg(_dev, _vreg, _on)                            \
        ({                                                              \
                int _ret;                                               \
                if (_on)                                                \
                        _ret = ufshcd_enable_vreg(_dev, _vreg);         \
                else                                                    \
                        _ret = ufshcd_disable_vreg(_dev, _vreg);        \
                _ret;                                                   \
        })

static u32 ufs_query_desc_max_size[] = {
        QUERY_DESC_DEVICE_MAX_SIZE,
        QUERY_DESC_CONFIGURAION_MAX_SIZE,
        QUERY_DESC_UNIT_MAX_SIZE,
        QUERY_DESC_RFU_MAX_SIZE,
        QUERY_DESC_INTERCONNECT_MAX_SIZE,
        QUERY_DESC_STRING_MAX_SIZE,
        QUERY_DESC_RFU_MAX_SIZE,
        QUERY_DESC_GEOMETRY_MAZ_SIZE,
        QUERY_DESC_POWER_MAX_SIZE,
        QUERY_DESC_RFU_MAX_SIZE,
};

enum {
        UFSHCD_MAX_CHANNEL      = 0,
        UFSHCD_MAX_ID           = 1,
        UFSHCD_CMD_PER_LUN      = 32,
        UFSHCD_CAN_QUEUE        = 32,
};

/* UFSHCD states */
enum {
        UFSHCD_STATE_RESET,
        UFSHCD_STATE_ERROR,
        UFSHCD_STATE_OPERATIONAL,
};

/* UFSHCD error handling flags */
enum {
        UFSHCD_EH_IN_PROGRESS = (1 << 0),
};

/* UFSHCD UIC layer error flags */
enum {
        UFSHCD_UIC_DL_PA_INIT_ERROR = (1 << 0), /* Data link layer error */
        UFSHCD_UIC_NL_ERROR = (1 << 1), /* Network layer error */
        UFSHCD_UIC_TL_ERROR = (1 << 2), /* Transport Layer error */
        UFSHCD_UIC_DME_ERROR = (1 << 3), /* DME error */
};

/* Interrupt configuration options */
enum {
        UFSHCD_INT_DISABLE,
        UFSHCD_INT_ENABLE,
        UFSHCD_INT_CLEAR,
};

#define ufshcd_set_eh_in_progress(h) \
        (h->eh_flags |= UFSHCD_EH_IN_PROGRESS)
#define ufshcd_eh_in_progress(h) \
        (h->eh_flags & UFSHCD_EH_IN_PROGRESS)
#define ufshcd_clear_eh_in_progress(h) \
        (h->eh_flags &= ~UFSHCD_EH_IN_PROGRESS)

#define ufshcd_set_ufs_dev_active(h) \
        ((h)->curr_dev_pwr_mode = UFS_ACTIVE_PWR_MODE)
#define ufshcd_set_ufs_dev_sleep(h) \
        ((h)->curr_dev_pwr_mode = UFS_SLEEP_PWR_MODE)
#define ufshcd_set_ufs_dev_poweroff(h) \
        ((h)->curr_dev_pwr_mode = UFS_POWERDOWN_PWR_MODE)
#define ufshcd_is_ufs_dev_active(h) \
        ((h)->curr_dev_pwr_mode == UFS_ACTIVE_PWR_MODE)
#define ufshcd_is_ufs_dev_sleep(h) \
        ((h)->curr_dev_pwr_mode == UFS_SLEEP_PWR_MODE)
#define ufshcd_is_ufs_dev_poweroff(h) \
        ((h)->curr_dev_pwr_mode == UFS_POWERDOWN_PWR_MODE)

static struct ufs_pm_lvl_states ufs_pm_lvl_states[] = {
        {UFS_ACTIVE_PWR_MODE, UIC_LINK_ACTIVE_STATE},
        {UFS_ACTIVE_PWR_MODE, UIC_LINK_HIBERN8_STATE},
        {UFS_SLEEP_PWR_MODE, UIC_LINK_ACTIVE_STATE},
        {UFS_SLEEP_PWR_MODE, UIC_LINK_HIBERN8_STATE},
        {UFS_POWERDOWN_PWR_MODE, UIC_LINK_HIBERN8_STATE},
        {UFS_POWERDOWN_PWR_MODE, UIC_LINK_OFF_STATE},
};

static inline enum ufs_dev_pwr_mode
ufs_get_pm_lvl_to_dev_pwr_mode(enum ufs_pm_level lvl)
{
        return ufs_pm_lvl_states[lvl].dev_state;
}

static inline enum uic_link_state
ufs_get_pm_lvl_to_link_pwr_state(enum ufs_pm_level lvl)
{
        return ufs_pm_lvl_states[lvl].link_state;
}

static void ufshcd_tmc_handler(struct ufs_hba *hba);
static void ufshcd_async_scan(void *data, async_cookie_t cookie);
static int ufshcd_reset_and_restore(struct ufs_hba *hba);
static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag);
static void ufshcd_hba_exit(struct ufs_hba *hba);
static int ufshcd_probe_hba(struct ufs_hba *hba);
static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
                                 bool skip_ref_clk);
static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on);
static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba);
static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
static irqreturn_t ufshcd_intr(int irq, void *__hba);
static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
                struct ufs_pa_layer_attr *desired_pwr_mode);

static inline int ufshcd_enable_irq(struct ufs_hba *hba)
{
        int ret = 0;

        if (!hba->is_irq_enabled) {
                ret = request_irq(hba->irq, ufshcd_intr, IRQF_SHARED, UFSHCD,
                                hba);
                if (ret)
                        dev_err(hba->dev, "%s: request_irq failed, ret=%d\n",
                                __func__, ret);
                hba->is_irq_enabled = true;
        }

        return ret;
}

static inline void ufshcd_disable_irq(struct ufs_hba *hba)
{
        if (hba->is_irq_enabled) {
                free_irq(hba->irq, hba);
                hba->is_irq_enabled = false;
        }
}

/*
 * ufshcd_wait_for_register - wait for register value to change
 * @hba - per-adapter interface
 * @reg - mmio register offset
 * @mask - mask to apply to read register value
 * @val - wait condition
 * @interval_us - polling interval in microsecs
 * @timeout_ms - timeout in millisecs
 *
 * Returns -ETIMEDOUT on error, zero on success
 */
static int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
                u32 val, unsigned long interval_us, unsigned long timeout_ms)
{
        int err = 0;
        unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);

        /* ignore bits that we don't intend to wait on */
        val = val & mask;

        while ((ufshcd_readl(hba, reg) & mask) != val) {
                /* wakeup within 50us of expiry */
                usleep_range(interval_us, interval_us + 50);

                if (time_after(jiffies, timeout)) {
                        if ((ufshcd_readl(hba, reg) & mask) != val)
                                err = -ETIMEDOUT;
                        break;
                }
        }

        return err;
}

/**
 * ufshcd_get_intr_mask - Get the interrupt bit mask
 * @hba - Pointer to adapter instance
 *
 * Returns interrupt bit mask per version
 */
static inline u32 ufshcd_get_intr_mask(struct ufs_hba *hba)
{
        if (hba->ufs_version == UFSHCI_VERSION_10)
                return INTERRUPT_MASK_ALL_VER_10;
        else
                return INTERRUPT_MASK_ALL_VER_11;
}

/**
 * ufshcd_get_ufs_version - Get the UFS version supported by the HBA
 * @hba - Pointer to adapter instance
 *
 * Returns UFSHCI version supported by the controller
 */
static inline u32 ufshcd_get_ufs_version(struct ufs_hba *hba)
{
        return ufshcd_readl(hba, REG_UFS_VERSION);
}

/**
 * ufshcd_is_device_present - Check if any device connected to
 *                            the host controller
 * @hba: pointer to adapter instance
 *
 * Returns 1 if device present, 0 if no device detected
 */
static inline int ufshcd_is_device_present(struct ufs_hba *hba)
{
        return (ufshcd_readl(hba, REG_CONTROLLER_STATUS) &
                                                DEVICE_PRESENT) ? 1 : 0;
}

/**
 * ufshcd_get_tr_ocs - Get the UTRD Overall Command Status
 * @lrb: pointer to local command reference block
 *
 * This function is used to get the OCS field from UTRD
 * Returns the OCS field in the UTRD
 */
static inline int ufshcd_get_tr_ocs(struct ufshcd_lrb *lrbp)
{
        return le32_to_cpu(lrbp->utr_descriptor_ptr->header.dword_2) & MASK_OCS;
}

/**
 * ufshcd_get_tmr_ocs - Get the UTMRD Overall Command Status
 * @task_req_descp: pointer to utp_task_req_desc structure
 *
 * This function is used to get the OCS field from UTMRD
 * Returns the OCS field in the UTMRD
 */
static inline int
ufshcd_get_tmr_ocs(struct utp_task_req_desc *task_req_descp)
{
        return le32_to_cpu(task_req_descp->header.dword_2) & MASK_OCS;
}

/**
 * ufshcd_get_tm_free_slot - get a free slot for task management request
 * @hba: per adapter instance
 * @free_slot: pointer to variable with available slot value
 *
 * Get a free tag and lock it until ufshcd_put_tm_slot() is called.
 * Returns 0 if free slot is not available, else return 1 with tag value
 * in @free_slot.
 */
static bool ufshcd_get_tm_free_slot(struct ufs_hba *hba, int *free_slot)
{
        int tag;
        bool ret = false;

        if (!free_slot)
                goto out;

        do {
                tag = find_first_zero_bit(&hba->tm_slots_in_use, hba->nutmrs);
                if (tag >= hba->nutmrs)
                        goto out;
        } while (test_and_set_bit_lock(tag, &hba->tm_slots_in_use));

        *free_slot = tag;
        ret = true;
out:
        return ret;
}

static inline void ufshcd_put_tm_slot(struct ufs_hba *hba, int slot)
{
        clear_bit_unlock(slot, &hba->tm_slots_in_use);
}

/**
 * ufshcd_utrl_clear - Clear a bit in UTRLCLR register
 * @hba: per adapter instance
 * @pos: position of the bit to be cleared
 */
static inline void ufshcd_utrl_clear(struct ufs_hba *hba, u32 pos)
{
        ufshcd_writel(hba, ~(1 << pos), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
}

/**
 * ufshcd_get_lists_status - Check UCRDY, UTRLRDY and UTMRLRDY
 * @reg: Register value of host controller status
 *
 * Returns integer, 0 on Success and positive value if failed
 */
static inline int ufshcd_get_lists_status(u32 reg)
{
        /*
         * The mask 0xFF is for the following HCS register bits
         * Bit          Description
         *  0           Device Present
         *  1           UTRLRDY
         *  2           UTMRLRDY
         *  3           UCRDY
         *  4           HEI
         *  5           DEI
         * 6-7          reserved
         */
        return (((reg) & (0xFF)) >> 1) ^ (0x07);
}

/**
 * ufshcd_get_uic_cmd_result - Get the UIC command result
 * @hba: Pointer to adapter instance
 *
 * This function gets the result of UIC command completion
 * Returns 0 on success, non zero value on error
 */
static inline int ufshcd_get_uic_cmd_result(struct ufs_hba *hba)
{
        return ufshcd_readl(hba, REG_UIC_COMMAND_ARG_2) &
               MASK_UIC_COMMAND_RESULT;
}

/**
 * ufshcd_get_dme_attr_val - Get the value of attribute returned by UIC command
 * @hba: Pointer to adapter instance
 *
 * This function gets UIC command argument3
 * Returns 0 on success, non zero value on error
 */
static inline u32 ufshcd_get_dme_attr_val(struct ufs_hba *hba)
{
        return ufshcd_readl(hba, REG_UIC_COMMAND_ARG_3);
}

/**
 * ufshcd_get_req_rsp - returns the TR response transaction type
 * @ucd_rsp_ptr: pointer to response UPIU
 */
static inline int
ufshcd_get_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
{
        return be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24;
}

/**
 * ufshcd_get_rsp_upiu_result - Get the result from response UPIU
 * @ucd_rsp_ptr: pointer to response UPIU
 *
 * This function gets the response status and scsi_status from response UPIU
 * Returns the response result code.
 */
static inline int
ufshcd_get_rsp_upiu_result(struct utp_upiu_rsp *ucd_rsp_ptr)
{
        return be32_to_cpu(ucd_rsp_ptr->header.dword_1) & MASK_RSP_UPIU_RESULT;
}

/*
 * ufshcd_get_rsp_upiu_data_seg_len - Get the data segment length
 *                              from response UPIU
 * @ucd_rsp_ptr: pointer to response UPIU
 *
 * Return the data segment length.
 */
static inline unsigned int
ufshcd_get_rsp_upiu_data_seg_len(struct utp_upiu_rsp *ucd_rsp_ptr)
{
        return be32_to_cpu(ucd_rsp_ptr->header.dword_2) &
                MASK_RSP_UPIU_DATA_SEG_LEN;
}

/**
 * ufshcd_is_exception_event - Check if the device raised an exception event
 * @ucd_rsp_ptr: pointer to response UPIU
 *
 * The function checks if the device raised an exception event indicated in
 * the Device Information field of response UPIU.
 *
 * Returns true if exception is raised, false otherwise.
 */
static inline bool ufshcd_is_exception_event(struct utp_upiu_rsp *ucd_rsp_ptr)
{
        return be32_to_cpu(ucd_rsp_ptr->header.dword_2) &
                        MASK_RSP_EXCEPTION_EVENT ? true : false;
}

/**
 * ufshcd_reset_intr_aggr - Reset interrupt aggregation values.
 * @hba: per adapter instance
 */
static inline void
ufshcd_reset_intr_aggr(struct ufs_hba *hba)
{
        ufshcd_writel(hba, INT_AGGR_ENABLE |
                      INT_AGGR_COUNTER_AND_TIMER_RESET,
                      REG_UTP_TRANSFER_REQ_INT_AGG_CONTROL);
}

/**
 * ufshcd_config_intr_aggr - Configure interrupt aggregation values.
 * @hba: per adapter instance
 * @cnt: Interrupt aggregation counter threshold
 * @tmout: Interrupt aggregation timeout value
 */
static inline void
ufshcd_config_intr_aggr(struct ufs_hba *hba, u8 cnt, u8 tmout)
{
        ufshcd_writel(hba, INT_AGGR_ENABLE | INT_AGGR_PARAM_WRITE |
                      INT_AGGR_COUNTER_THLD_VAL(cnt) |
                      INT_AGGR_TIMEOUT_VAL(tmout),
                      REG_UTP_TRANSFER_REQ_INT_AGG_CONTROL);
}

/**
 * ufshcd_enable_run_stop_reg - Enable run-stop registers,
 *                      When run-stop registers are set to 1, it indicates the
 *                      host controller that it can process the requests
 * @hba: per adapter instance
 */
static void ufshcd_enable_run_stop_reg(struct ufs_hba *hba)
{
        ufshcd_writel(hba, UTP_TASK_REQ_LIST_RUN_STOP_BIT,
                      REG_UTP_TASK_REQ_LIST_RUN_STOP);
        ufshcd_writel(hba, UTP_TRANSFER_REQ_LIST_RUN_STOP_BIT,
                      REG_UTP_TRANSFER_REQ_LIST_RUN_STOP);
}

/**
 * ufshcd_hba_start - Start controller initialization sequence
 * @hba: per adapter instance
 */
static inline void ufshcd_hba_start(struct ufs_hba *hba)
{
        ufshcd_writel(hba, CONTROLLER_ENABLE, REG_CONTROLLER_ENABLE);
}

/**
 * ufshcd_is_hba_active - Get controller state
 * @hba: per adapter instance
 *
 * Returns zero if controller is active, 1 otherwise
 */
static inline int ufshcd_is_hba_active(struct ufs_hba *hba)
{
        return (ufshcd_readl(hba, REG_CONTROLLER_ENABLE) & 0x1) ? 0 : 1;
}

static void ufshcd_ungate_work(struct work_struct *work)
{
        int ret;
        unsigned long flags;
        struct ufs_hba *hba = container_of(work, struct ufs_hba,
                        clk_gating.ungate_work);

        cancel_delayed_work_sync(&hba->clk_gating.gate_work);

        spin_lock_irqsave(hba->host->host_lock, flags);
        if (hba->clk_gating.state == CLKS_ON) {
                spin_unlock_irqrestore(hba->host->host_lock, flags);
                goto unblock_reqs;
        }

        spin_unlock_irqrestore(hba->host->host_lock, flags);
        ufshcd_setup_clocks(hba, true);

        /* Exit from hibern8 */
        if (ufshcd_can_hibern8_during_gating(hba)) {
                /* Prevent gating in this path */
                hba->clk_gating.is_suspended = true;
                if (ufshcd_is_link_hibern8(hba)) {
                        ret = ufshcd_uic_hibern8_exit(hba);
                        if (ret)
                                dev_err(hba->dev, "%s: hibern8 exit failed %d\n",
                                        __func__, ret);
                        else
                                ufshcd_set_link_active(hba);
                }
                hba->clk_gating.is_suspended = false;
        }
unblock_reqs:
        if (ufshcd_is_clkscaling_enabled(hba))
                devfreq_resume_device(hba->devfreq);
        scsi_unblock_requests(hba->host);
}

/**
 * ufshcd_hold - Enable clocks that were gated earlier due to ufshcd_release.
 * Also, exit from hibern8 mode and set the link as active.
 * @hba: per adapter instance
 * @async: This indicates whether caller should ungate clocks asynchronously.
 */
int ufshcd_hold(struct ufs_hba *hba, bool async)
{
        int rc = 0;
        unsigned long flags;

        if (!ufshcd_is_clkgating_allowed(hba))
                goto out;
        spin_lock_irqsave(hba->host->host_lock, flags);
        hba->clk_gating.active_reqs++;

start:
        switch (hba->clk_gating.state) {
        case CLKS_ON:
                break;
        case REQ_CLKS_OFF:
                if (cancel_delayed_work(&hba->clk_gating.gate_work)) {
                        hba->clk_gating.state = CLKS_ON;
                        break;
                }
                /*
                 * If we here, it means gating work is either done or
                 * currently running. Hence, fall through to cancel gating
                 * work and to enable clocks.
                 */
        case CLKS_OFF:
                scsi_block_requests(hba->host);
                hba->clk_gating.state = REQ_CLKS_ON;
                schedule_work(&hba->clk_gating.ungate_work);
                /*
                 * fall through to check if we should wait for this
                 * work to be done or not.
                 */
        case REQ_CLKS_ON:
                if (async) {
                        rc = -EAGAIN;
                        hba->clk_gating.active_reqs--;
                        break;
                }

                spin_unlock_irqrestore(hba->host->host_lock, flags);
                flush_work(&hba->clk_gating.ungate_work);
                /* Make sure state is CLKS_ON before returning */
                spin_lock_irqsave(hba->host->host_lock, flags);
                goto start;
        default:
                dev_err(hba->dev, "%s: clk gating is in invalid state %d\n",
                                __func__, hba->clk_gating.state);
                break;
        }
        spin_unlock_irqrestore(hba->host->host_lock, flags);
out:
        return rc;
}

static void ufshcd_gate_work(struct work_struct *work)
{
        struct ufs_hba *hba = container_of(work, struct ufs_hba,
                        clk_gating.gate_work.work);
        unsigned long flags;

        spin_lock_irqsave(hba->host->host_lock, flags);
        if (hba->clk_gating.is_suspended) {
                hba->clk_gating.state = CLKS_ON;
                goto rel_lock;
        }

        if (hba->clk_gating.active_reqs
                || hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL
                || hba->lrb_in_use || hba->outstanding_tasks
                || hba->active_uic_cmd || hba->uic_async_done)
                goto rel_lock;

        spin_unlock_irqrestore(hba->host->host_lock, flags);

        /* put the link into hibern8 mode before turning off clocks */
        if (ufshcd_can_hibern8_during_gating(hba)) {
                if (ufshcd_uic_hibern8_enter(hba)) {
                        hba->clk_gating.state = CLKS_ON;
                        goto out;
                }
                ufshcd_set_link_hibern8(hba);
        }

        if (ufshcd_is_clkscaling_enabled(hba)) {
                devfreq_suspend_device(hba->devfreq);
                hba->clk_scaling.window_start_t = 0;
        }

        if (!ufshcd_is_link_active(hba))
                ufshcd_setup_clocks(hba, false);
        else
                /* If link is active, device ref_clk can't be switched off */
                __ufshcd_setup_clocks(hba, false, true);

        /*
         * In case you are here to cancel this work the gating state
         * would be marked as REQ_CLKS_ON. In this case keep the state
         * as REQ_CLKS_ON which would anyway imply that clocks are off
         * and a request to turn them on is pending. By doing this way,
         * we keep the state machine in tact and this would ultimately
         * prevent from doing cancel work multiple times when there are
         * new requests arriving before the current cancel work is done.
         */
        spin_lock_irqsave(hba->host->host_lock, flags);
        if (hba->clk_gating.state == REQ_CLKS_OFF)
                hba->clk_gating.state = CLKS_OFF;

rel_lock:
        spin_unlock_irqrestore(hba->host->host_lock, flags);
out:
        return;
}

/* host lock must be held before calling this variant */
static void __ufshcd_release(struct ufs_hba *hba)
{
        if (!ufshcd_is_clkgating_allowed(hba))
                return;

        hba->clk_gating.active_reqs--;

        if (hba->clk_gating.active_reqs || hba->clk_gating.is_suspended
                || hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL
                || hba->lrb_in_use || hba->outstanding_tasks
                || hba->active_uic_cmd || hba->uic_async_done)
                return;

        hba->clk_gating.state = REQ_CLKS_OFF;
        schedule_delayed_work(&hba->clk_gating.gate_work,
                        msecs_to_jiffies(hba->clk_gating.delay_ms));
}

void ufshcd_release(struct ufs_hba *hba)
{
        unsigned long flags;

        spin_lock_irqsave(hba->host->host_lock, flags);
        __ufshcd_release(hba);
        spin_unlock_irqrestore(hba->host->host_lock, flags);
}

static ssize_t ufshcd_clkgate_delay_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct ufs_hba *hba = dev_get_drvdata(dev);

        return snprintf(buf, PAGE_SIZE, "%lu\n", hba->clk_gating.delay_ms);
}

static ssize_t ufshcd_clkgate_delay_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
{
        struct ufs_hba *hba = dev_get_drvdata(dev);
        unsigned long flags, value;

        if (kstrtoul(buf, 0, &value))
                return -EINVAL;

        spin_lock_irqsave(hba->host->host_lock, flags);
        hba->clk_gating.delay_ms = value;
        spin_unlock_irqrestore(hba->host->host_lock, flags);
        return count;
}

static void ufshcd_init_clk_gating(struct ufs_hba *hba)
{
        if (!ufshcd_is_clkgating_allowed(hba))
                return;

        hba->clk_gating.delay_ms = 150;
        INIT_DELAYED_WORK(&hba->clk_gating.gate_work, ufshcd_gate_work);
        INIT_WORK(&hba->clk_gating.ungate_work, ufshcd_ungate_work);

        hba->clk_gating.delay_attr.show = ufshcd_clkgate_delay_show;
        hba->clk_gating.delay_attr.store = ufshcd_clkgate_delay_store;
        sysfs_attr_init(&hba->clk_gating.delay_attr.attr);
        hba->clk_gating.delay_attr.attr.name = "clkgate_delay_ms";
        hba->clk_gating.delay_attr.attr.mode = S_IRUGO | S_IWUSR;
        if (device_create_file(hba->dev, &hba->clk_gating.delay_attr))
                dev_err(hba->dev, "Failed to create sysfs for clkgate_delay\n");
}

static void ufshcd_exit_clk_gating(struct ufs_hba *hba)
{
        if (!ufshcd_is_clkgating_allowed(hba))
                return;
        device_remove_file(hba->dev, &hba->clk_gating.delay_attr);
}

/* Must be called with host lock acquired */
static void ufshcd_clk_scaling_start_busy(struct ufs_hba *hba)
{
        if (!ufshcd_is_clkscaling_enabled(hba))
                return;

        if (!hba->clk_scaling.is_busy_started) {
                hba->clk_scaling.busy_start_t = ktime_get();
                hba->clk_scaling.is_busy_started = true;
        }
}

static void ufshcd_clk_scaling_update_busy(struct ufs_hba *hba)
{
        struct ufs_clk_scaling *scaling = &hba->clk_scaling;

        if (!ufshcd_is_clkscaling_enabled(hba))
                return;

        if (!hba->outstanding_reqs && scaling->is_busy_started) {
                scaling->tot_busy_t += ktime_to_us(ktime_sub(ktime_get(),
                                        scaling->busy_start_t));
                scaling->busy_start_t = ktime_set(0, 0);
                scaling->is_busy_started = false;
        }
}
/**
 * ufshcd_send_command - Send SCSI or device management commands
 * @hba: per adapter instance
 * @task_tag: Task tag of the command
 */
static inline
void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
{
        ufshcd_clk_scaling_start_busy(hba);
        __set_bit(task_tag, &hba->outstanding_reqs);
        ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL);
}

/**
 * ufshcd_copy_sense_data - Copy sense data in case of check condition
 * @lrb - pointer to local reference block
 */
static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
{
        int len;
        if (lrbp->sense_buffer &&
            ufshcd_get_rsp_upiu_data_seg_len(lrbp->ucd_rsp_ptr)) {
                len = be16_to_cpu(lrbp->ucd_rsp_ptr->sr.sense_data_len);
                memcpy(lrbp->sense_buffer,
                        lrbp->ucd_rsp_ptr->sr.sense_data,
                        min_t(int, len, SCSI_SENSE_BUFFERSIZE));
        }
}

/**
 * ufshcd_copy_query_response() - Copy the Query Response and the data
 * descriptor
 * @hba: per adapter instance
 * @lrb - pointer to local reference block
 */
static
int ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
{
        struct ufs_query_res *query_res = &hba->dev_cmd.query.response;

        memcpy(&query_res->upiu_res, &lrbp->ucd_rsp_ptr->qr, QUERY_OSF_SIZE);

        /* Get the descriptor */
        if (lrbp->ucd_rsp_ptr->qr.opcode == UPIU_QUERY_OPCODE_READ_DESC) {
                u8 *descp = (u8 *)lrbp->ucd_rsp_ptr +
                                GENERAL_UPIU_REQUEST_SIZE;
                u16 resp_len;
                u16 buf_len;

                /* data segment length */
                resp_len = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_2) &
                                                MASK_QUERY_DATA_SEG_LEN;
                buf_len = be16_to_cpu(
                                hba->dev_cmd.query.request.upiu_req.length);
                if (likely(buf_len >= resp_len)) {
                        memcpy(hba->dev_cmd.query.descriptor, descp, resp_len);
                } else {
                        dev_warn(hba->dev,
                                "%s: Response size is bigger than buffer",
                                __func__);
                        return -EINVAL;
                }
        }

        return 0;
}

/**
 * ufshcd_hba_capabilities - Read controller capabilities
 * @hba: per adapter instance
 */
static inline void ufshcd_hba_capabilities(struct ufs_hba *hba)
{
        hba->capabilities = ufshcd_readl(hba, REG_CONTROLLER_CAPABILITIES);

        /* nutrs and nutmrs are 0 based values */
        hba->nutrs = (hba->capabilities & MASK_TRANSFER_REQUESTS_SLOTS) + 1;
        hba->nutmrs =
        ((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1;
}

/**
 * ufshcd_ready_for_uic_cmd - Check if controller is ready
 *                            to accept UIC commands
 * @hba: per adapter instance
 * Return true on success, else false
 */
static inline bool ufshcd_ready_for_uic_cmd(struct ufs_hba *hba)
{
        if (ufshcd_readl(hba, REG_CONTROLLER_STATUS) & UIC_COMMAND_READY)
                return true;
        else
                return false;
}

/**
 * ufshcd_get_upmcrs - Get the power mode change request status
 * @hba: Pointer to adapter instance
 *
 * This function gets the UPMCRS field of HCS register
 * Returns value of UPMCRS field
 */
static inline u8 ufshcd_get_upmcrs(struct ufs_hba *hba)
{
        return (ufshcd_readl(hba, REG_CONTROLLER_STATUS) >> 8) & 0x7;
}

/**
 * ufshcd_dispatch_uic_cmd - Dispatch UIC commands to unipro layers
 * @hba: per adapter instance
 * @uic_cmd: UIC command
 *
 * Mutex must be held.
 */
static inline void
ufshcd_dispatch_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
{
        WARN_ON(hba->active_uic_cmd);

        hba->active_uic_cmd = uic_cmd;

        /* Write Args */
        ufshcd_writel(hba, uic_cmd->argument1, REG_UIC_COMMAND_ARG_1);
        ufshcd_writel(hba, uic_cmd->argument2, REG_UIC_COMMAND_ARG_2);
        ufshcd_writel(hba, uic_cmd->argument3, REG_UIC_COMMAND_ARG_3);

        /* Write UIC Cmd */
        ufshcd_writel(hba, uic_cmd->command & COMMAND_OPCODE_MASK,
                      REG_UIC_COMMAND);
}

/**
 * ufshcd_wait_for_uic_cmd - Wait complectioin of UIC command
 * @hba: per adapter instance
 * @uic_command: UIC command
 *
 * Must be called with mutex held.
 * Returns 0 only if success.
 */
static int
ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
{
        int ret;
        unsigned long flags;

        if (wait_for_completion_timeout(&uic_cmd->done,
                                        msecs_to_jiffies(UIC_CMD_TIMEOUT)))
                ret = uic_cmd->argument2 & MASK_UIC_COMMAND_RESULT;
        else
                ret = -ETIMEDOUT;

        spin_lock_irqsave(hba->host->host_lock, flags);
        hba->active_uic_cmd = NULL;
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        return ret;
}

/**
 * __ufshcd_send_uic_cmd - Send UIC commands and retrieve the result
 * @hba: per adapter instance
 * @uic_cmd: UIC command
 *
 * Identical to ufshcd_send_uic_cmd() expect mutex. Must be called
 * with mutex held and host_lock locked.
 * Returns 0 only if success.
 */
static int
__ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
{
        if (!ufshcd_ready_for_uic_cmd(hba)) {
                dev_err(hba->dev,
                        "Controller not ready to accept UIC commands\n");
                return -EIO;
        }

        init_completion(&uic_cmd->done);

        ufshcd_dispatch_uic_cmd(hba, uic_cmd);

        return 0;
}

/**
 * ufshcd_send_uic_cmd - Send UIC commands and retrieve the result
 * @hba: per adapter instance
 * @uic_cmd: UIC command
 *
 * Returns 0 only if success.
 */
static int
ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
{
        int ret;
        unsigned long flags;

        ufshcd_hold(hba, false);
        mutex_lock(&hba->uic_cmd_mutex);
        spin_lock_irqsave(hba->host->host_lock, flags);
        ret = __ufshcd_send_uic_cmd(hba, uic_cmd);
        spin_unlock_irqrestore(hba->host->host_lock, flags);
        if (!ret)
                ret = ufshcd_wait_for_uic_cmd(hba, uic_cmd);

        mutex_unlock(&hba->uic_cmd_mutex);

        ufshcd_release(hba);
        return ret;
}

/**
 * ufshcd_map_sg - Map scatter-gather list to prdt
 * @lrbp - pointer to local reference block
 *
 * Returns 0 in case of success, non-zero value in case of failure
 */
static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
{
        struct ufshcd_sg_entry *prd_table;
        struct scatterlist *sg;
        struct scsi_cmnd *cmd;
        int sg_segments;
        int i;

        cmd = lrbp->cmd;
        sg_segments = scsi_dma_map(cmd);
        if (sg_segments < 0)
                return sg_segments;

        if (sg_segments) {
                lrbp->utr_descriptor_ptr->prd_table_length =
                                        cpu_to_le16((u16) (sg_segments));

                prd_table = (struct ufshcd_sg_entry *)lrbp->ucd_prdt_ptr;

                scsi_for_each_sg(cmd, sg, sg_segments, i) {
                        prd_table[i].size  =
                                cpu_to_le32(((u32) sg_dma_len(sg))-1);
                        prd_table[i].base_addr =
                                cpu_to_le32(lower_32_bits(sg->dma_address));
                        prd_table[i].upper_addr =
                                cpu_to_le32(upper_32_bits(sg->dma_address));
                }
        } else {
                lrbp->utr_descriptor_ptr->prd_table_length = 0;
        }

        return 0;
}

/**
 * ufshcd_enable_intr - enable interrupts
 * @hba: per adapter instance
 * @intrs: interrupt bits
 */
static void ufshcd_enable_intr(struct ufs_hba *hba, u32 intrs)
{
        u32 set = ufshcd_readl(hba, REG_INTERRUPT_ENABLE);

        if (hba->ufs_version == UFSHCI_VERSION_10) {
                u32 rw;
                rw = set & INTERRUPT_MASK_RW_VER_10;
                set = rw | ((set ^ intrs) & intrs);
        } else {
                set |= intrs;
        }

        ufshcd_writel(hba, set, REG_INTERRUPT_ENABLE);
}

/**
 * ufshcd_disable_intr - disable interrupts
 * @hba: per adapter instance
 * @intrs: interrupt bits
 */
static void ufshcd_disable_intr(struct ufs_hba *hba, u32 intrs)
{
        u32 set = ufshcd_readl(hba, REG_INTERRUPT_ENABLE);

        if (hba->ufs_version == UFSHCI_VERSION_10) {
                u32 rw;
                rw = (set & INTERRUPT_MASK_RW_VER_10) &
                        ~(intrs & INTERRUPT_MASK_RW_VER_10);
                set = rw | ((set & intrs) & ~INTERRUPT_MASK_RW_VER_10);

        } else {
                set &= ~intrs;
        }

        ufshcd_writel(hba, set, REG_INTERRUPT_ENABLE);
}

/**
 * ufshcd_prepare_req_desc_hdr() - Fills the requests header
 * descriptor according to request
 * @lrbp: pointer to local reference block
 * @upiu_flags: flags required in the header
 * @cmd_dir: requests data direction
 */
static void ufshcd_prepare_req_desc_hdr(struct ufshcd_lrb *lrbp,
                u32 *upiu_flags, enum dma_data_direction cmd_dir)
{
        struct utp_transfer_req_desc *req_desc = lrbp->utr_descriptor_ptr;
        u32 data_direction;
        u32 dword_0;

        if (cmd_dir == DMA_FROM_DEVICE) {
                data_direction = UTP_DEVICE_TO_HOST;
                *upiu_flags = UPIU_CMD_FLAGS_READ;
        } else if (cmd_dir == DMA_TO_DEVICE) {
                data_direction = UTP_HOST_TO_DEVICE;
                *upiu_flags = UPIU_CMD_FLAGS_WRITE;
        } else {
                data_direction = UTP_NO_DATA_TRANSFER;
                *upiu_flags = UPIU_CMD_FLAGS_NONE;
        }

        dword_0 = data_direction | (lrbp->command_type
                                << UPIU_COMMAND_TYPE_OFFSET);
        if (lrbp->intr_cmd)
                dword_0 |= UTP_REQ_DESC_INT_CMD;

        /* Transfer request descriptor header fields */
        req_desc->header.dword_0 = cpu_to_le32(dword_0);

        /*
         * assigning invalid value for command status. Controller
         * updates OCS on command completion, with the command
         * status
         */
        req_desc->header.dword_2 =
                cpu_to_le32(OCS_INVALID_COMMAND_STATUS);
}

/**
 * ufshcd_prepare_utp_scsi_cmd_upiu() - fills the utp_transfer_req_desc,
 * for scsi commands
 * @lrbp - local reference block pointer
 * @upiu_flags - flags
 */
static
void ufshcd_prepare_utp_scsi_cmd_upiu(struct ufshcd_lrb *lrbp, u32 upiu_flags)
{
        struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;

        /* command descriptor fields */
        ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
                                UPIU_TRANSACTION_COMMAND, upiu_flags,
                                lrbp->lun, lrbp->task_tag);
        ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
                                UPIU_COMMAND_SET_TYPE_SCSI, 0, 0, 0);

        /* Total EHS length and Data segment length will be zero */
        ucd_req_ptr->header.dword_2 = 0;

        ucd_req_ptr->sc.exp_data_transfer_len =
                cpu_to_be32(lrbp->cmd->sdb.length);

        memcpy(ucd_req_ptr->sc.cdb, lrbp->cmd->cmnd,
                (min_t(unsigned short, lrbp->cmd->cmd_len, MAX_CDB_SIZE)));
}

/**
 * ufshcd_prepare_utp_query_req_upiu() - fills the utp_transfer_req_desc,
 * for query requsts
 * @hba: UFS hba
 * @lrbp: local reference block pointer
 * @upiu_flags: flags
 */
static void ufshcd_prepare_utp_query_req_upiu(struct ufs_hba *hba,
                                struct ufshcd_lrb *lrbp, u32 upiu_flags)
{
        struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;
        struct ufs_query *query = &hba->dev_cmd.query;
        u16 len = be16_to_cpu(query->request.upiu_req.length);
        u8 *descp = (u8 *)lrbp->ucd_req_ptr + GENERAL_UPIU_REQUEST_SIZE;

        /* Query request header */
        ucd_req_ptr->header.dword_0 = UPIU_HEADER_DWORD(
                        UPIU_TRANSACTION_QUERY_REQ, upiu_flags,
                        lrbp->lun, lrbp->task_tag);
        ucd_req_ptr->header.dword_1 = UPIU_HEADER_DWORD(
                        0, query->request.query_func, 0, 0);

        /* Data segment length */
        ucd_req_ptr->header.dword_2 = UPIU_HEADER_DWORD(
                        0, 0, len >> 8, (u8)len);

        /* Copy the Query Request buffer as is */
        memcpy(&ucd_req_ptr->qr, &query->request.upiu_req,
                        QUERY_OSF_SIZE);

        /* Copy the Descriptor */
        if (query->request.upiu_req.opcode == UPIU_QUERY_OPCODE_WRITE_DESC)
                memcpy(descp, query->descriptor, len);

}

static inline void ufshcd_prepare_utp_nop_upiu(struct ufshcd_lrb *lrbp)
{
        struct utp_upiu_req *ucd_req_ptr = lrbp->ucd_req_ptr;

        memset(ucd_req_ptr, 0, sizeof(struct utp_upiu_req));

        /* command descriptor fields */
        ucd_req_ptr->header.dword_0 =
                UPIU_HEADER_DWORD(
                        UPIU_TRANSACTION_NOP_OUT, 0, 0, lrbp->task_tag);
}

/**
 * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
 * @hba - per adapter instance
 * @lrb - pointer to local reference block
 */
static int ufshcd_compose_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
{
        u32 upiu_flags;
        int ret = 0;

        switch (lrbp->command_type) {
        case UTP_CMD_TYPE_SCSI:
                if (likely(lrbp->cmd)) {
                        ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags,
                                        lrbp->cmd->sc_data_direction);
                        ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags);
                } else {
                        ret = -EINVAL;
                }
                break;
        case UTP_CMD_TYPE_DEV_MANAGE:
                ufshcd_prepare_req_desc_hdr(lrbp, &upiu_flags, DMA_NONE);
                if (hba->dev_cmd.type == DEV_CMD_TYPE_QUERY)
                        ufshcd_prepare_utp_query_req_upiu(
                                        hba, lrbp, upiu_flags);
                else if (hba->dev_cmd.type == DEV_CMD_TYPE_NOP)
                        ufshcd_prepare_utp_nop_upiu(lrbp);
                else
                        ret = -EINVAL;
                break;
        case UTP_CMD_TYPE_UFS:
                /* For UFS native command implementation */
                ret = -ENOTSUPP;
                dev_err(hba->dev, "%s: UFS native command are not supported\n",
                        __func__);
                break;
        default:
                ret = -ENOTSUPP;
                dev_err(hba->dev, "%s: unknown command type: 0x%x\n",
                                __func__, lrbp->command_type);
                break;
        } /* end of switch */

        return ret;
}

/*
 * ufshcd_scsi_to_upiu_lun - maps scsi LUN to UPIU LUN
 * @scsi_lun: scsi LUN id
 *
 * Returns UPIU LUN id
 */
static inline u8 ufshcd_scsi_to_upiu_lun(unsigned int scsi_lun)
{
        if (scsi_is_wlun(scsi_lun))
                return (scsi_lun & UFS_UPIU_MAX_UNIT_NUM_ID)
                        | UFS_UPIU_WLUN_ID;
        else
                return scsi_lun & UFS_UPIU_MAX_UNIT_NUM_ID;
}

/**
 * ufshcd_upiu_wlun_to_scsi_wlun - maps UPIU W-LUN id to SCSI W-LUN ID
 * @scsi_lun: UPIU W-LUN id
 *
 * Returns SCSI W-LUN id
 */
static inline u16 ufshcd_upiu_wlun_to_scsi_wlun(u8 upiu_wlun_id)
{
        return (upiu_wlun_id & ~UFS_UPIU_WLUN_ID) | SCSI_W_LUN_BASE;
}

/**
 * ufshcd_queuecommand - main entry point for SCSI requests
 * @cmd: command from SCSI Midlayer
 * @done: call back function
 *
 * Returns 0 for success, non-zero in case of failure
 */
static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
{
        struct ufshcd_lrb *lrbp;
        struct ufs_hba *hba;
        unsigned long flags;
        int tag;
        int err = 0;

        hba = shost_priv(host);

        tag = cmd->request->tag;

        spin_lock_irqsave(hba->host->host_lock, flags);
        switch (hba->ufshcd_state) {
        case UFSHCD_STATE_OPERATIONAL:
                break;
        case UFSHCD_STATE_RESET:
                err = SCSI_MLQUEUE_HOST_BUSY;
                goto out_unlock;
        case UFSHCD_STATE_ERROR:
                set_host_byte(cmd, DID_ERROR);
                cmd->scsi_done(cmd);
                goto out_unlock;
        default:
                dev_WARN_ONCE(hba->dev, 1, "%s: invalid state %d\n",
                                __func__, hba->ufshcd_state);
                set_host_byte(cmd, DID_BAD_TARGET);
                cmd->scsi_done(cmd);
                goto out_unlock;
        }
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        /* acquire the tag to make sure device cmds don't use it */
        if (test_and_set_bit_lock(tag, &hba->lrb_in_use)) {
                /*
                 * Dev manage command in progress, requeue the command.
                 * Requeuing the command helps in cases where the request *may*
                 * find different tag instead of waiting for dev manage command
                 * completion.
                 */
                err = SCSI_MLQUEUE_HOST_BUSY;
                goto out;
        }

        err = ufshcd_hold(hba, true);
        if (err) {
                err = SCSI_MLQUEUE_HOST_BUSY;
                clear_bit_unlock(tag, &hba->lrb_in_use);
                goto out;
        }
        WARN_ON(hba->clk_gating.state != CLKS_ON);

        lrbp = &hba->lrb[tag];

        WARN_ON(lrbp->cmd);
        lrbp->cmd = cmd;
        lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
        lrbp->sense_buffer = cmd->sense_buffer;
        lrbp->task_tag = tag;
        lrbp->lun = ufshcd_scsi_to_upiu_lun(cmd->device->lun);
        lrbp->intr_cmd = false;
        lrbp->command_type = UTP_CMD_TYPE_SCSI;

        /* form UPIU before issuing the command */
        ufshcd_compose_upiu(hba, lrbp);
        err = ufshcd_map_sg(lrbp);
        if (err) {
                lrbp->cmd = NULL;
                clear_bit_unlock(tag, &hba->lrb_in_use);
                goto out;
        }

        /* issue command to the controller */
        spin_lock_irqsave(hba->host->host_lock, flags);
        ufshcd_send_command(hba, tag);
out_unlock:
        spin_unlock_irqrestore(hba->host->host_lock, flags);
out:
        return err;
}

static int ufshcd_compose_dev_cmd(struct ufs_hba *hba,
                struct ufshcd_lrb *lrbp, enum dev_cmd_type cmd_type, int tag)
{
        lrbp->cmd = NULL;
        lrbp->sense_bufflen = 0;
        lrbp->sense_buffer = NULL;
        lrbp->task_tag = tag;
        lrbp->lun = 0; /* device management cmd is not specific to any LUN */
        lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
        lrbp->intr_cmd = true; /* No interrupt aggregation */
        hba->dev_cmd.type = cmd_type;

        return ufshcd_compose_upiu(hba, lrbp);
}

static int
ufshcd_clear_cmd(struct ufs_hba *hba, int tag)
{
        int err = 0;
        unsigned long flags;
        u32 mask = 1 << tag;

        /* clear outstanding transaction before retry */
        spin_lock_irqsave(hba->host->host_lock, flags);
        ufshcd_utrl_clear(hba, tag);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        /*
         * wait for for h/w to clear corresponding bit in door-bell.
         * max. wait is 1 sec.
         */
        err = ufshcd_wait_for_register(hba,
                        REG_UTP_TRANSFER_REQ_DOOR_BELL,
                        mask, ~mask, 1000, 1000);

        return err;
}

static int
ufshcd_check_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
{
        struct ufs_query_res *query_res = &hba->dev_cmd.query.response;

        /* Get the UPIU response */
        query_res->response = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr) >>
                                UPIU_RSP_CODE_OFFSET;
        return query_res->response;
}

/**
 * ufshcd_dev_cmd_completion() - handles device management command responses
 * @hba: per adapter instance
 * @lrbp: pointer to local reference block
 */
static int
ufshcd_dev_cmd_completion(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
{
        int resp;
        int err = 0;

        resp = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);

        switch (resp) {
        case UPIU_TRANSACTION_NOP_IN:
                if (hba->dev_cmd.type != DEV_CMD_TYPE_NOP) {
                        err = -EINVAL;
                        dev_err(hba->dev, "%s: unexpected response %x\n",
                                        __func__, resp);
                }
                break;
        case UPIU_TRANSACTION_QUERY_RSP:
                err = ufshcd_check_query_response(hba, lrbp);
                if (!err)
                        err = ufshcd_copy_query_response(hba, lrbp);
                break;
        case UPIU_TRANSACTION_REJECT_UPIU:
                /* TODO: handle Reject UPIU Response */
                err = -EPERM;
                dev_err(hba->dev, "%s: Reject UPIU not fully implemented\n",
                                __func__);
                break;
        default:
                err = -EINVAL;
                dev_err(hba->dev, "%s: Invalid device management cmd response: %x\n",
                                __func__, resp);
                break;
        }

        return err;
}

static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
                struct ufshcd_lrb *lrbp, int max_timeout)
{
        int err = 0;
        unsigned long time_left;
        unsigned long flags;

        time_left = wait_for_completion_timeout(hba->dev_cmd.complete,
                        msecs_to_jiffies(max_timeout));

        spin_lock_irqsave(hba->host->host_lock, flags);
        hba->dev_cmd.complete = NULL;
        if (likely(time_left)) {
                err = ufshcd_get_tr_ocs(lrbp);
                if (!err)
                        err = ufshcd_dev_cmd_completion(hba, lrbp);
        }
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        if (!time_left) {
                err = -ETIMEDOUT;
                if (!ufshcd_clear_cmd(hba, lrbp->task_tag))
                        /* sucessfully cleared the command, retry if needed */
                        err = -EAGAIN;
        }

        return err;
}

/**
 * ufshcd_get_dev_cmd_tag - Get device management command tag
 * @hba: per-adapter instance
 * @tag: pointer to variable with available slot value
 *
 * Get a free slot and lock it until device management command
 * completes.
 *
 * Returns false if free slot is unavailable for locking, else
 * return true with tag value in @tag.
 */
static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out)
{
        int tag;
        bool ret = false;
        unsigned long tmp;

        if (!tag_out)
                goto out;

        do {
                tmp = ~hba->lrb_in_use;
                tag = find_last_bit(&tmp, hba->nutrs);
                if (tag >= hba->nutrs)
                        goto out;
        } while (test_and_set_bit_lock(tag, &hba->lrb_in_use));

        *tag_out = tag;
        ret = true;
out:
        return ret;
}

static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag)
{
        clear_bit_unlock(tag, &hba->lrb_in_use);
}

/**
 * ufshcd_exec_dev_cmd - API for sending device management requests
 * @hba - UFS hba
 * @cmd_type - specifies the type (NOP, Query...)
 * @timeout - time in seconds
 *
 * NOTE: Since there is only one available tag for device management commands,
 * it is expected you hold the hba->dev_cmd.lock mutex.
 */
static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
                enum dev_cmd_type cmd_type, int timeout)
{
        struct ufshcd_lrb *lrbp;
        int err;
        int tag;
        struct completion wait;
        unsigned long flags;

        /*
         * Get free slot, sleep if slots are unavailable.
         * Even though we use wait_event() which sleeps indefinitely,
         * the maximum wait time is bounded by SCSI request timeout.
         */
        wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag));

        init_completion(&wait);
        lrbp = &hba->lrb[tag];
        WARN_ON(lrbp->cmd);
        err = ufshcd_compose_dev_cmd(hba, lrbp, cmd_type, tag);
        if (unlikely(err))
                goto out_put_tag;

        hba->dev_cmd.complete = &wait;

        spin_lock_irqsave(hba->host->host_lock, flags);
        ufshcd_send_command(hba, tag);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);

out_put_tag:
        ufshcd_put_dev_cmd_tag(hba, tag);
        wake_up(&hba->dev_cmd.tag_wq);
        return err;
}

/**
 * ufshcd_init_query() - init the query response and request parameters
 * @hba: per-adapter instance
 * @request: address of the request pointer to be initialized
 * @response: address of the response pointer to be initialized
 * @opcode: operation to perform
 * @idn: flag idn to access
 * @index: LU number to access
 * @selector: query/flag/descriptor further identification
 */
static inline void ufshcd_init_query(struct ufs_hba *hba,
                struct ufs_query_req **request, struct ufs_query_res **response,
                enum query_opcode opcode, u8 idn, u8 index, u8 selector)
{
        *request = &hba->dev_cmd.query.request;
        *response = &hba->dev_cmd.query.response;
        memset(*request, 0, sizeof(struct ufs_query_req));
        memset(*response, 0, sizeof(struct ufs_query_res));
        (*request)->upiu_req.opcode = opcode;
        (*request)->upiu_req.idn = idn;
        (*request)->upiu_req.index = index;
        (*request)->upiu_req.selector = selector;
}

/**
 * ufshcd_query_flag() - API function for sending flag query requests
 * hba: per-adapter instance
 * query_opcode: flag query to perform
 * idn: flag idn to access
 * flag_res: the flag value after the query request completes
 *
 * Returns 0 for success, non-zero in case of failure
 */
static int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
                        enum flag_idn idn, bool *flag_res)
{
        struct ufs_query_req *request = NULL;
        struct ufs_query_res *response = NULL;
        int err, index = 0, selector = 0;

        BUG_ON(!hba);

        ufshcd_hold(hba, false);
        mutex_lock(&hba->dev_cmd.lock);
        ufshcd_init_query(hba, &request, &response, opcode, idn, index,
                        selector);

        switch (opcode) {
        case UPIU_QUERY_OPCODE_SET_FLAG:
        case UPIU_QUERY_OPCODE_CLEAR_FLAG:
        case UPIU_QUERY_OPCODE_TOGGLE_FLAG:
                request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
                break;
        case UPIU_QUERY_OPCODE_READ_FLAG:
                request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
                if (!flag_res) {
                        /* No dummy reads */
                        dev_err(hba->dev, "%s: Invalid argument for read request\n",
                                        __func__);
                        err = -EINVAL;
                        goto out_unlock;
                }
                break;
        default:
                dev_err(hba->dev,
                        "%s: Expected query flag opcode but got = %d\n",
                        __func__, opcode);
                err = -EINVAL;
                goto out_unlock;
        }

        err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);

        if (err) {
                dev_err(hba->dev,
                        "%s: Sending flag query for idn %d failed, err = %d\n",
                        __func__, idn, err);
                goto out_unlock;
        }

        if (flag_res)
                *flag_res = (be32_to_cpu(response->upiu_res.value) &
                                MASK_QUERY_UPIU_FLAG_LOC) & 0x1;

out_unlock:
        mutex_unlock(&hba->dev_cmd.lock);
        ufshcd_release(hba);
        return err;
}

/**
 * ufshcd_query_attr - API function for sending attribute requests
 * hba: per-adapter instance
 * opcode: attribute opcode
 * idn: attribute idn to access
 * index: index field
 * selector: selector field
 * attr_val: the attribute value after the query request completes
 *
 * Returns 0 for success, non-zero in case of failure
*/
static int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
                        enum attr_idn idn, u8 index, u8 selector, u32 *attr_val)
{
        struct ufs_query_req *request = NULL;
        struct ufs_query_res *response = NULL;
        int err;

        BUG_ON(!hba);

        ufshcd_hold(hba, false);
        if (!attr_val) {
                dev_err(hba->dev, "%s: attribute value required for opcode 0x%x\n",
                                __func__, opcode);
                err = -EINVAL;
                goto out;
        }

        mutex_lock(&hba->dev_cmd.lock);
        ufshcd_init_query(hba, &request, &response, opcode, idn, index,
                        selector);

        switch (opcode) {
        case UPIU_QUERY_OPCODE_WRITE_ATTR:
                request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
                request->upiu_req.value = cpu_to_be32(*attr_val);
                break;
        case UPIU_QUERY_OPCODE_READ_ATTR:
                request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
                break;
        default:
                dev_err(hba->dev, "%s: Expected query attr opcode but got = 0x%.2x\n",
                                __func__, opcode);
                err = -EINVAL;
                goto out_unlock;
        }

        err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);

        if (err) {
                dev_err(hba->dev, "%s: opcode 0x%.2x for idn %d failed, err = %d\n",
                                __func__, opcode, idn, err);
                goto out_unlock;
        }

        *attr_val = be32_to_cpu(response->upiu_res.value);

out_unlock:
        mutex_unlock(&hba->dev_cmd.lock);
out:
        ufshcd_release(hba);
        return err;
}

/**
 * ufshcd_query_descriptor - API function for sending descriptor requests
 * hba: per-adapter instance
 * opcode: attribute opcode
 * idn: attribute idn to access
 * index: index field
 * selector: selector field
 * desc_buf: the buffer that contains the descriptor
 * buf_len: length parameter passed to the device
 *
 * Returns 0 for success, non-zero in case of failure.
 * The buf_len parameter will contain, on return, the length parameter
 * received on the response.
 */
static int ufshcd_query_descriptor(struct ufs_hba *hba,
                        enum query_opcode opcode, enum desc_idn idn, u8 index,
                        u8 selector, u8 *desc_buf, int *buf_len)
{
        struct ufs_query_req *request = NULL;
        struct ufs_query_res *response = NULL;
        int err;

        BUG_ON(!hba);

        ufshcd_hold(hba, false);
        if (!desc_buf) {
                dev_err(hba->dev, "%s: descriptor buffer required for opcode 0x%x\n",
                                __func__, opcode);
                err = -EINVAL;
                goto out;
        }

        if (*buf_len <= QUERY_DESC_MIN_SIZE || *buf_len > QUERY_DESC_MAX_SIZE) {
                dev_err(hba->dev, "%s: descriptor buffer size (%d) is out of range\n",
                                __func__, *buf_len);
                err = -EINVAL;
                goto out;
        }

        mutex_lock(&hba->dev_cmd.lock);
        ufshcd_init_query(hba, &request, &response, opcode, idn, index,
                        selector);
        hba->dev_cmd.query.descriptor = desc_buf;
        request->upiu_req.length = cpu_to_be16(*buf_len);

        switch (opcode) {
        case UPIU_QUERY_OPCODE_WRITE_DESC:
                request->query_func = UPIU_QUERY_FUNC_STANDARD_WRITE_REQUEST;
                break;
        case UPIU_QUERY_OPCODE_READ_DESC:
                request->query_func = UPIU_QUERY_FUNC_STANDARD_READ_REQUEST;
                break;
        default:
                dev_err(hba->dev,
                                "%s: Expected query descriptor opcode but got = 0x%.2x\n",
                                __func__, opcode);
                err = -EINVAL;
                goto out_unlock;
        }

        err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_QUERY, QUERY_REQ_TIMEOUT);

        if (err) {
                dev_err(hba->dev, "%s: opcode 0x%.2x for idn %d failed, err = %d\n",
                                __func__, opcode, idn, err);
                goto out_unlock;
        }

        hba->dev_cmd.query.descriptor = NULL;
        *buf_len = be16_to_cpu(response->upiu_res.length);

out_unlock:
        mutex_unlock(&hba->dev_cmd.lock);
out:
        ufshcd_release(hba);
        return err;
}

/**
 * ufshcd_read_desc_param - read the specified descriptor parameter
 * @hba: Pointer to adapter instance
 * @desc_id: descriptor idn value
 * @desc_index: descriptor index
 * @param_offset: offset of the parameter to read
 * @param_read_buf: pointer to buffer where parameter would be read
 * @param_size: sizeof(param_read_buf)
 *
 * Return 0 in case of success, non-zero otherwise
 */
static int ufshcd_read_desc_param(struct ufs_hba *hba,
                                  enum desc_idn desc_id,
                                  int desc_index,
                                  u32 param_offset,
                                  u8 *param_read_buf,
                                  u32 param_size)
{
        int ret;
        u8 *desc_buf;
        u32 buff_len;
        bool is_kmalloc = true;

        /* safety checks */
        if (desc_id >= QUERY_DESC_IDN_MAX)
                return -EINVAL;

        buff_len = ufs_query_desc_max_size[desc_id];
        if ((param_offset + param_size) > buff_len)
                return -EINVAL;

        if (!param_offset && (param_size == buff_len)) {
                /* memory space already available to hold full descriptor */
                desc_buf = param_read_buf;
                is_kmalloc = false;
        } else {
                /* allocate memory to hold full descriptor */
                desc_buf = kmalloc(buff_len, GFP_KERNEL);
                if (!desc_buf)
                        return -ENOMEM;
        }

        ret = ufshcd_query_descriptor(hba, UPIU_QUERY_OPCODE_READ_DESC,
                                      desc_id, desc_index, 0, desc_buf,
                                      &buff_len);

        if (ret || (buff_len < ufs_query_desc_max_size[desc_id]) ||
            (desc_buf[QUERY_DESC_LENGTH_OFFSET] !=
             ufs_query_desc_max_size[desc_id])
            || (desc_buf[QUERY_DESC_DESC_TYPE_OFFSET] != desc_id)) {
                dev_err(hba->dev, "%s: Failed reading descriptor. desc_id %d param_offset %d buff_len %d ret %d",
                        __func__, desc_id, param_offset, buff_len, ret);
                if (!ret)
                        ret = -EINVAL;

                goto out;
        }

        if (is_kmalloc)
                memcpy(param_read_buf, &desc_buf[param_offset], param_size);
out:
        if (is_kmalloc)
                kfree(desc_buf);
        return ret;
}

static inline int ufshcd_read_desc(struct ufs_hba *hba,
                                   enum desc_idn desc_id,
                                   int desc_index,
                                   u8 *buf,
                                   u32 size)
{
        return ufshcd_read_desc_param(hba, desc_id, desc_index, 0, buf, size);
}

static inline int ufshcd_read_power_desc(struct ufs_hba *hba,
                                         u8 *buf,
                                         u32 size)
{
        return ufshcd_read_desc(hba, QUERY_DESC_IDN_POWER, 0, buf, size);
}

/**
 * ufshcd_read_unit_desc_param - read the specified unit descriptor parameter
 * @hba: Pointer to adapter instance
 * @lun: lun id
 * @param_offset: offset of the parameter to read
 * @param_read_buf: pointer to buffer where parameter would be read
 * @param_size: sizeof(param_read_buf)
 *
 * Return 0 in case of success, non-zero otherwise
 */
static inline int ufshcd_read_unit_desc_param(struct ufs_hba *hba,
                                              int lun,
                                              enum unit_desc_param param_offset,
                                              u8 *param_read_buf,
                                              u32 param_size)
{
        /*
         * Unit descriptors are only available for general purpose LUs (LUN id
         * from 0 to 7) and RPMB Well known LU.
         */
        if (lun != UFS_UPIU_RPMB_WLUN && (lun >= UFS_UPIU_MAX_GENERAL_LUN))
                return -EOPNOTSUPP;

        return ufshcd_read_desc_param(hba, QUERY_DESC_IDN_UNIT, lun,
                                      param_offset, param_read_buf, param_size);
}

/**
 * ufshcd_memory_alloc - allocate memory for host memory space data structures
 * @hba: per adapter instance
 *
 * 1. Allocate DMA memory for Command Descriptor array
 *      Each command descriptor consist of Command UPIU, Response UPIU and PRDT
 * 2. Allocate DMA memory for UTP Transfer Request Descriptor List (UTRDL).
 * 3. Allocate DMA memory for UTP Task Management Request Descriptor List
 *      (UTMRDL)
 * 4. Allocate memory for local reference block(lrb).
 *
 * Returns 0 for success, non-zero in case of failure
 */
static int ufshcd_memory_alloc(struct ufs_hba *hba)
{
        size_t utmrdl_size, utrdl_size, ucdl_size;

        /* Allocate memory for UTP command descriptors */
        ucdl_size = (sizeof(struct utp_transfer_cmd_desc) * hba->nutrs);
        hba->ucdl_base_addr = dmam_alloc_coherent(hba->dev,
                                                  ucdl_size,
                                                  &hba->ucdl_dma_addr,
                                                  GFP_KERNEL);

        /*
         * UFSHCI requires UTP command descriptor to be 128 byte aligned.
         * make sure hba->ucdl_dma_addr is aligned to PAGE_SIZE
         * if hba->ucdl_dma_addr is aligned to PAGE_SIZE, then it will
         * be aligned to 128 bytes as well
         */
        if (!hba->ucdl_base_addr ||
            WARN_ON(hba->ucdl_dma_addr & (PAGE_SIZE - 1))) {
                dev_err(hba->dev,
                        "Command Descriptor Memory allocation failed\n");
                goto out;
        }

        /*
         * Allocate memory for UTP Transfer descriptors
         * UFSHCI requires 1024 byte alignment of UTRD
         */
        utrdl_size = (sizeof(struct utp_transfer_req_desc) * hba->nutrs);
        hba->utrdl_base_addr = dmam_alloc_coherent(hba->dev,
                                                   utrdl_size,
                                                   &hba->utrdl_dma_addr,
                                                   GFP_KERNEL);
        if (!hba->utrdl_base_addr ||
            WARN_ON(hba->utrdl_dma_addr & (PAGE_SIZE - 1))) {
                dev_err(hba->dev,
                        "Transfer Descriptor Memory allocation failed\n");
                goto out;
        }

        /*
         * Allocate memory for UTP Task Management descriptors
         * UFSHCI requires 1024 byte alignment of UTMRD
         */
        utmrdl_size = sizeof(struct utp_task_req_desc) * hba->nutmrs;
        hba->utmrdl_base_addr = dmam_alloc_coherent(hba->dev,
                                                    utmrdl_size,
                                                    &hba->utmrdl_dma_addr,
                                                    GFP_KERNEL);
        if (!hba->utmrdl_base_addr ||
            WARN_ON(hba->utmrdl_dma_addr & (PAGE_SIZE - 1))) {
                dev_err(hba->dev,
                "Task Management Descriptor Memory allocation failed\n");
                goto out;
        }

        /* Allocate memory for local reference block */
        hba->lrb = devm_kzalloc(hba->dev,
                                hba->nutrs * sizeof(struct ufshcd_lrb),
                                GFP_KERNEL);
        if (!hba->lrb) {
                dev_err(hba->dev, "LRB Memory allocation failed\n");
                goto out;
        }
        return 0;
out:
        return -ENOMEM;
}

/**
 * ufshcd_host_memory_configure - configure local reference block with
 *                              memory offsets
 * @hba: per adapter instance
 *
 * Configure Host memory space
 * 1. Update Corresponding UTRD.UCDBA and UTRD.UCDBAU with UCD DMA
 * address.
 * 2. Update each UTRD with Response UPIU offset, Response UPIU length
 * and PRDT offset.
 * 3. Save the corresponding addresses of UTRD, UCD.CMD, UCD.RSP and UCD.PRDT
 * into local reference block.
 */
static void ufshcd_host_memory_configure(struct ufs_hba *hba)
{
        struct utp_transfer_cmd_desc *cmd_descp;
        struct utp_transfer_req_desc *utrdlp;
        dma_addr_t cmd_desc_dma_addr;
        dma_addr_t cmd_desc_element_addr;
        u16 response_offset;
        u16 prdt_offset;
        int cmd_desc_size;
        int i;

        utrdlp = hba->utrdl_base_addr;
        cmd_descp = hba->ucdl_base_addr;

        response_offset =
                offsetof(struct utp_transfer_cmd_desc, response_upiu);
        prdt_offset =
                offsetof(struct utp_transfer_cmd_desc, prd_table);

        cmd_desc_size = sizeof(struct utp_transfer_cmd_desc);
        cmd_desc_dma_addr = hba->ucdl_dma_addr;

        for (i = 0; i < hba->nutrs; i++) {
                /* Configure UTRD with command descriptor base address */
                cmd_desc_element_addr =
                                (cmd_desc_dma_addr + (cmd_desc_size * i));
                utrdlp[i].command_desc_base_addr_lo =
                                cpu_to_le32(lower_32_bits(cmd_desc_element_addr));
                utrdlp[i].command_desc_base_addr_hi =
                                cpu_to_le32(upper_32_bits(cmd_desc_element_addr));

                /* Response upiu and prdt offset should be in double words */
                utrdlp[i].response_upiu_offset =
                                cpu_to_le16((response_offset >> 2));
                utrdlp[i].prd_table_offset =
                                cpu_to_le16((prdt_offset >> 2));
                utrdlp[i].response_upiu_length =
                                cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);

                hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
                hba->lrb[i].ucd_req_ptr =
                        (struct utp_upiu_req *)(cmd_descp + i);
                hba->lrb[i].ucd_rsp_ptr =
                        (struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
                hba->lrb[i].ucd_prdt_ptr =
                        (struct ufshcd_sg_entry *)cmd_descp[i].prd_table;
        }
}

/**
 * ufshcd_dme_link_startup - Notify Unipro to perform link startup
 * @hba: per adapter instance
 *
 * UIC_CMD_DME_LINK_STARTUP command must be issued to Unipro layer,
 * in order to initialize the Unipro link startup procedure.
 * Once the Unipro links are up, the device connected to the controller
 * is detected.
 *
 * Returns 0 on success, non-zero value on failure
 */
static int ufshcd_dme_link_startup(struct ufs_hba *hba)
{
        struct uic_command uic_cmd = {0};
        int ret;

        uic_cmd.command = UIC_CMD_DME_LINK_STARTUP;

        ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
        if (ret)
                dev_err(hba->dev,
                        "dme-link-startup: error code %d\n", ret);
        return ret;
}

/**
 * ufshcd_dme_set_attr - UIC command for DME_SET, DME_PEER_SET
 * @hba: per adapter instance
 * @attr_sel: uic command argument1
 * @attr_set: attribute set type as uic command argument2
 * @mib_val: setting value as uic command argument3
 * @peer: indicate whether peer or local
 *
 * Returns 0 on success, non-zero value on failure
 */
int ufshcd_dme_set_attr(struct ufs_hba *hba, u32 attr_sel,
                        u8 attr_set, u32 mib_val, u8 peer)
{
        struct uic_command uic_cmd = {0};
        static const char *const action[] = {
                "dme-set",
                "dme-peer-set"
        };
        const char *set = action[!!peer];
        int ret;

        uic_cmd.command = peer ?
                UIC_CMD_DME_PEER_SET : UIC_CMD_DME_SET;
        uic_cmd.argument1 = attr_sel;
        uic_cmd.argument2 = UIC_ARG_ATTR_TYPE(attr_set);
        uic_cmd.argument3 = mib_val;

        ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
        if (ret)
                dev_err(hba->dev, "%s: attr-id 0x%x val 0x%x error code %d\n",
                        set, UIC_GET_ATTR_ID(attr_sel), mib_val, ret);

        return ret;
}
EXPORT_SYMBOL_GPL(ufshcd_dme_set_attr);

/**
 * ufshcd_dme_get_attr - UIC command for DME_GET, DME_PEER_GET
 * @hba: per adapter instance
 * @attr_sel: uic command argument1
 * @mib_val: the value of the attribute as returned by the UIC command
 * @peer: indicate whether peer or local
 *
 * Returns 0 on success, non-zero value on failure
 */
int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
                        u32 *mib_val, u8 peer)
{
        struct uic_command uic_cmd = {0};
        static const char *const action[] = {
                "dme-get",
                "dme-peer-get"
        };
        const char *get = action[!!peer];
        int ret;

        uic_cmd.command = peer ?
                UIC_CMD_DME_PEER_GET : UIC_CMD_DME_GET;
        uic_cmd.argument1 = attr_sel;

        ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
        if (ret) {
                dev_err(hba->dev, "%s: attr-id 0x%x error code %d\n",
                        get, UIC_GET_ATTR_ID(attr_sel), ret);
                goto out;
        }

        if (mib_val)
                *mib_val = uic_cmd.argument3;
out:
        return ret;
}
EXPORT_SYMBOL_GPL(ufshcd_dme_get_attr);

/**
 * ufshcd_uic_pwr_ctrl - executes UIC commands (which affects the link power
 * state) and waits for it to take effect.
 *
 * @hba: per adapter instance
 * @cmd: UIC command to execute
 *
 * DME operations like DME_SET(PA_PWRMODE), DME_HIBERNATE_ENTER &
 * DME_HIBERNATE_EXIT commands take some time to take its effect on both host
 * and device UniPro link and hence it's final completion would be indicated by
 * dedicated status bits in Interrupt Status register (UPMS, UHES, UHXS) in
 * addition to normal UIC command completion Status (UCCS). This function only
 * returns after the relevant status bits indicate the completion.
 *
 * Returns 0 on success, non-zero value on failure
 */
static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba, struct uic_command *cmd)
{
        struct completion uic_async_done;
        unsigned long flags;
        u8 status;
        int ret;

        mutex_lock(&hba->uic_cmd_mutex);
        init_completion(&uic_async_done);

        spin_lock_irqsave(hba->host->host_lock, flags);
        hba->uic_async_done = &uic_async_done;
        ret = __ufshcd_send_uic_cmd(hba, cmd);
        spin_unlock_irqrestore(hba->host->host_lock, flags);
        if (ret) {
                dev_err(hba->dev,
                        "pwr ctrl cmd 0x%x with mode 0x%x uic error %d\n",
                        cmd->command, cmd->argument3, ret);
                goto out;
        }
        ret = ufshcd_wait_for_uic_cmd(hba, cmd);
        if (ret) {
                dev_err(hba->dev,
                        "pwr ctrl cmd 0x%x with mode 0x%x uic error %d\n",
                        cmd->command, cmd->argument3, ret);
                goto out;
        }

        if (!wait_for_completion_timeout(hba->uic_async_done,
                                         msecs_to_jiffies(UIC_CMD_TIMEOUT))) {
                dev_err(hba->dev,
                        "pwr ctrl cmd 0x%x with mode 0x%x completion timeout\n",
                        cmd->command, cmd->argument3);
                ret = -ETIMEDOUT;
                goto out;
        }

        status = ufshcd_get_upmcrs(hba);
        if (status != PWR_LOCAL) {
                dev_err(hba->dev,
                        "pwr ctrl cmd 0x%0x failed, host umpcrs:0x%x\n",
                        cmd->command, status);
                ret = (status != PWR_OK) ? status : -1;
        }
out:
        spin_lock_irqsave(hba->host->host_lock, flags);
        hba->uic_async_done = NULL;
        spin_unlock_irqrestore(hba->host->host_lock, flags);
        mutex_unlock(&hba->uic_cmd_mutex);

        return ret;
}

/**
 * ufshcd_uic_change_pwr_mode - Perform the UIC power mode chage
 *                              using DME_SET primitives.
 * @hba: per adapter instance
 * @mode: powr mode value
 *
 * Returns 0 on success, non-zero value on failure
 */
static int ufshcd_uic_change_pwr_mode(struct ufs_hba *hba, u8 mode)
{
        struct uic_command uic_cmd = {0};
        int ret;

        uic_cmd.command = UIC_CMD_DME_SET;
        uic_cmd.argument1 = UIC_ARG_MIB(PA_PWRMODE);
        uic_cmd.argument3 = mode;
        ufshcd_hold(hba, false);
        ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
        ufshcd_release(hba);

        return ret;
}

static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
{
        struct uic_command uic_cmd = {0};

        uic_cmd.command = UIC_CMD_DME_HIBER_ENTER;

        return ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
}

static int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
{
        struct uic_command uic_cmd = {0};
        int ret;

        uic_cmd.command = UIC_CMD_DME_HIBER_EXIT;
        ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
        if (ret) {
                ufshcd_set_link_off(hba);
                ret = ufshcd_host_reset_and_restore(hba);
        }

        return ret;
}

/**
 * ufshcd_get_max_pwr_mode - reads the max power mode negotiated with device
 * @hba: per-adapter instance
 */
static int ufshcd_get_max_pwr_mode(struct ufs_hba *hba)
{
        struct ufs_pa_layer_attr *pwr_info = &hba->max_pwr_info.info;

        if (hba->max_pwr_info.is_valid)
                return 0;

        pwr_info->pwr_tx = FASTAUTO_MODE;
        pwr_info->pwr_rx = FASTAUTO_MODE;
        pwr_info->hs_rate = PA_HS_MODE_B;

        /* Get the connected lane count */
        ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDRXDATALANES),
                        &pwr_info->lane_rx);
        ufshcd_dme_get(hba, UIC_ARG_MIB(PA_CONNECTEDTXDATALANES),
                        &pwr_info->lane_tx);

        if (!pwr_info->lane_rx || !pwr_info->lane_tx) {
                dev_err(hba->dev, "%s: invalid connected lanes value. rx=%d, tx=%d\n",
                                __func__,
                                pwr_info->lane_rx,
                                pwr_info->lane_tx);
                return -EINVAL;
        }

        /*
         * First, get the maximum gears of HS speed.
         * If a zero value, it means there is no HSGEAR capability.
         * Then, get the maximum gears of PWM speed.
         */
        ufshcd_dme_get(hba, UIC_ARG_MIB(PA_MAXRXHSGEAR), &pwr_info->gear_rx);
        if (!pwr_info->gear_rx) {
                ufshcd_dme_get(hba, UIC_ARG_MIB(PA_MAXRXPWMGEAR),
                                &pwr_info->gear_rx);
                if (!pwr_info->gear_rx) {
                        dev_err(hba->dev, "%s: invalid max pwm rx gear read = %d\n",
                                __func__, pwr_info->gear_rx);
                        return -EINVAL;
                }
                pwr_info->pwr_rx = SLOWAUTO_MODE;
        }

        ufshcd_dme_peer_get(hba, UIC_ARG_MIB(PA_MAXRXHSGEAR),
                        &pwr_info->gear_tx);
        if (!pwr_info->gear_tx) {
                ufshcd_dme_peer_get(hba, UIC_ARG_MIB(PA_MAXRXPWMGEAR),
                                &pwr_info->gear_tx);
                if (!pwr_info->gear_tx) {
                        dev_err(hba->dev, "%s: invalid max pwm tx gear read = %d\n",
                                __func__, pwr_info->gear_tx);
                        return -EINVAL;
                }
                pwr_info->pwr_tx = SLOWAUTO_MODE;
        }

        hba->max_pwr_info.is_valid = true;
        return 0;
}

static int ufshcd_change_power_mode(struct ufs_hba *hba,
                             struct ufs_pa_layer_attr *pwr_mode)
{
        int ret;

        /* if already configured to the requested pwr_mode */
        if (pwr_mode->gear_rx == hba->pwr_info.gear_rx &&
            pwr_mode->gear_tx == hba->pwr_info.gear_tx &&
            pwr_mode->lane_rx == hba->pwr_info.lane_rx &&
            pwr_mode->lane_tx == hba->pwr_info.lane_tx &&
            pwr_mode->pwr_rx == hba->pwr_info.pwr_rx &&
            pwr_mode->pwr_tx == hba->pwr_info.pwr_tx &&
            pwr_mode->hs_rate == hba->pwr_info.hs_rate) {
                dev_dbg(hba->dev, "%s: power already configured\n", __func__);
                return 0;
        }

        /*
         * Configure attributes for power mode change with below.
         * - PA_RXGEAR, PA_ACTIVERXDATALANES, PA_RXTERMINATION,
         * - PA_TXGEAR, PA_ACTIVETXDATALANES, PA_TXTERMINATION,
         * - PA_HSSERIES
         */
        ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXGEAR), pwr_mode->gear_rx);
        ufshcd_dme_set(hba, UIC_ARG_MIB(PA_ACTIVERXDATALANES),
                        pwr_mode->lane_rx);
        if (pwr_mode->pwr_rx == FASTAUTO_MODE ||
                        pwr_mode->pwr_rx == FAST_MODE)
                ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXTERMINATION), TRUE);
        else
                ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXTERMINATION), FALSE);

        ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXGEAR), pwr_mode->gear_tx);
        ufshcd_dme_set(hba, UIC_ARG_MIB(PA_ACTIVETXDATALANES),
                        pwr_mode->lane_tx);
        if (pwr_mode->pwr_tx == FASTAUTO_MODE ||
                        pwr_mode->pwr_tx == FAST_MODE)
                ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXTERMINATION), TRUE);
        else
                ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXTERMINATION), FALSE);

        if (pwr_mode->pwr_rx == FASTAUTO_MODE ||
            pwr_mode->pwr_tx == FASTAUTO_MODE ||
            pwr_mode->pwr_rx == FAST_MODE ||
            pwr_mode->pwr_tx == FAST_MODE)
                ufshcd_dme_set(hba, UIC_ARG_MIB(PA_HSSERIES),
                                                pwr_mode->hs_rate);

        ret = ufshcd_uic_change_pwr_mode(hba, pwr_mode->pwr_rx << 4
                        | pwr_mode->pwr_tx);

        if (ret) {
                dev_err(hba->dev,
                        "%s: power mode change failed %d\n", __func__, ret);
        } else {
                if (hba->vops && hba->vops->pwr_change_notify)
                        hba->vops->pwr_change_notify(hba,
                                POST_CHANGE, NULL, pwr_mode);

                memcpy(&hba->pwr_info, pwr_mode,
                        sizeof(struct ufs_pa_layer_attr));
        }

        return ret;
}

/**
 * ufshcd_config_pwr_mode - configure a new power mode
 * @hba: per-adapter instance
 * @desired_pwr_mode: desired power configuration
 */
static int ufshcd_config_pwr_mode(struct ufs_hba *hba,
                struct ufs_pa_layer_attr *desired_pwr_mode)
{
        struct ufs_pa_layer_attr final_params = { 0 };
        int ret;

        if (hba->vops && hba->vops->pwr_change_notify)
                hba->vops->pwr_change_notify(hba,
                     PRE_CHANGE, desired_pwr_mode, &final_params);
        else
                memcpy(&final_params, desired_pwr_mode, sizeof(final_params));

        ret = ufshcd_change_power_mode(hba, &final_params);

        return ret;
}

/**
 * ufshcd_complete_dev_init() - checks device readiness
 * hba: per-adapter instance
 *
 * Set fDeviceInit flag and poll until device toggles it.
 */
static int ufshcd_complete_dev_init(struct ufs_hba *hba)
{
        int i, retries, err = 0;
        bool flag_res = 1;

        for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
                /* Set the fDeviceInit flag */
                err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_SET_FLAG,
                                        QUERY_FLAG_IDN_FDEVICEINIT, NULL);
                if (!err || err == -ETIMEDOUT)
                        break;
                dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
        }
        if (err) {
                dev_err(hba->dev,
                        "%s setting fDeviceInit flag failed with error %d\n",
                        __func__, err);
                goto out;
        }

        /* poll for max. 100 iterations for fDeviceInit flag to clear */
        for (i = 0; i < 100 && !err && flag_res; i++) {
                for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
                        err = ufshcd_query_flag(hba,
                                        UPIU_QUERY_OPCODE_READ_FLAG,
                                        QUERY_FLAG_IDN_FDEVICEINIT, &flag_res);
                        if (!err || err == -ETIMEDOUT)
                                break;
                        dev_dbg(hba->dev, "%s: error %d retrying\n", __func__,
                                        err);
                }
        }
        if (err)
                dev_err(hba->dev,
                        "%s reading fDeviceInit flag failed with error %d\n",
                        __func__, err);
        else if (flag_res)
                dev_err(hba->dev,
                        "%s fDeviceInit was not cleared by the device\n",
                        __func__);

out:
        return err;
}

/**
 * ufshcd_make_hba_operational - Make UFS controller operational
 * @hba: per adapter instance
 *
 * To bring UFS host controller to operational state,
 * 1. Enable required interrupts
 * 2. Configure interrupt aggregation
 * 3. Program UTRL and UTMRL base addres
 * 4. Configure run-stop-registers
 *
 * Returns 0 on success, non-zero value on failure
 */
static int ufshcd_make_hba_operational(struct ufs_hba *hba)
{
        int err = 0;
        u32 reg;

        /* Enable required interrupts */
        ufshcd_enable_intr(hba, UFSHCD_ENABLE_INTRS);

        /* Configure interrupt aggregation */
        ufshcd_config_intr_aggr(hba, hba->nutrs - 1, INT_AGGR_DEF_TO);

        /* Configure UTRL and UTMRL base address registers */
        ufshcd_writel(hba, lower_32_bits(hba->utrdl_dma_addr),
                        REG_UTP_TRANSFER_REQ_LIST_BASE_L);
        ufshcd_writel(hba, upper_32_bits(hba->utrdl_dma_addr),
                        REG_UTP_TRANSFER_REQ_LIST_BASE_H);
        ufshcd_writel(hba, lower_32_bits(hba->utmrdl_dma_addr),
                        REG_UTP_TASK_REQ_LIST_BASE_L);
        ufshcd_writel(hba, upper_32_bits(hba->utmrdl_dma_addr),
                        REG_UTP_TASK_REQ_LIST_BASE_H);

        /*
         * UCRDY, UTMRLDY and UTRLRDY bits must be 1
         * DEI, HEI bits must be 0
         */
        reg = ufshcd_readl(hba, REG_CONTROLLER_STATUS);
        if (!(ufshcd_get_lists_status(reg))) {
                ufshcd_enable_run_stop_reg(hba);
        } else {
                dev_err(hba->dev,
                        "Host controller not ready to process requests");
                err = -EIO;
                goto out;
        }

out:
        return err;
}

/**
 * ufshcd_hba_enable - initialize the controller
 * @hba: per adapter instance
 *
 * The controller resets itself and controller firmware initialization
 * sequence kicks off. When controller is ready it will set
 * the Host Controller Enable bit to 1.
 *
 * Returns 0 on success, non-zero value on failure
 */
static int ufshcd_hba_enable(struct ufs_hba *hba)
{
        int retry;

        /*
         * msleep of 1 and 5 used in this function might result in msleep(20),
         * but it was necessary to send the UFS FPGA to reset mode during
         * development and testing of this driver. msleep can be changed to
         * mdelay and retry count can be reduced based on the controller.
         */
        if (!ufshcd_is_hba_active(hba)) {

                /* change controller state to "reset state" */
                ufshcd_hba_stop(hba);

                /*
                 * This delay is based on the testing done with UFS host
                 * controller FPGA. The delay can be changed based on the
                 * host controller used.
                 */
                msleep(5);
        }

        /* UniPro link is disabled at this point */
        ufshcd_set_link_off(hba);

        if (hba->vops && hba->vops->hce_enable_notify)
                hba->vops->hce_enable_notify(hba, PRE_CHANGE);

        /* start controller initialization sequence */
        ufshcd_hba_start(hba);

        /*
         * To initialize a UFS host controller HCE bit must be set to 1.
         * During initialization the HCE bit value changes from 1->0->1.
         * When the host controller completes initialization sequence
         * it sets the value of HCE bit to 1. The same HCE bit is read back
         * to check if the controller has completed initialization sequence.
         * So without this delay the value HCE = 1, set in the previous
         * instruction might be read back.
         * This delay can be changed based on the controller.
         */
        msleep(1);

        /* wait for the host controller to complete initialization */
        retry = 10;
        while (ufshcd_is_hba_active(hba)) {
                if (retry) {
                        retry--;
                } else {
                        dev_err(hba->dev,
                                "Controller enable failed\n");
                        return -EIO;
                }
                msleep(5);
        }

        /* enable UIC related interrupts */
        ufshcd_enable_intr(hba, UFSHCD_UIC_MASK);

        if (hba->vops && hba->vops->hce_enable_notify)
                hba->vops->hce_enable_notify(hba, POST_CHANGE);

        return 0;
}

/**
 * ufshcd_link_startup - Initialize unipro link startup
 * @hba: per adapter instance
 *
 * Returns 0 for success, non-zero in case of failure
 */
static int ufshcd_link_startup(struct ufs_hba *hba)
{
        int ret;
        int retries = DME_LINKSTARTUP_RETRIES;

        do {
                if (hba->vops && hba->vops->link_startup_notify)
                        hba->vops->link_startup_notify(hba, PRE_CHANGE);

                ret = ufshcd_dme_link_startup(hba);

                /* check if device is detected by inter-connect layer */
                if (!ret && !ufshcd_is_device_present(hba)) {
                        dev_err(hba->dev, "%s: Device not present\n", __func__);
                        ret = -ENXIO;
                        goto out;
                }

                /*
                 * DME link lost indication is only received when link is up,
                 * but we can't be sure if the link is up until link startup
                 * succeeds. So reset the local Uni-Pro and try again.
                 */
                if (ret && ufshcd_hba_enable(hba))
                        goto out;
        } while (ret && retries--);

        if (ret)
                /* failed to get the link up... retire */
                goto out;

        /* Include any host controller configuration via UIC commands */
        if (hba->vops && hba->vops->link_startup_notify) {
                ret = hba->vops->link_startup_notify(hba, POST_CHANGE);
                if (ret)
                        goto out;
        }

        ret = ufshcd_make_hba_operational(hba);
out:
        if (ret)
                dev_err(hba->dev, "link startup failed %d\n", ret);
        return ret;
}

/**
 * ufshcd_verify_dev_init() - Verify device initialization
 * @hba: per-adapter instance
 *
 * Send NOP OUT UPIU and wait for NOP IN response to check whether the
 * device Transport Protocol (UTP) layer is ready after a reset.
 * If the UTP layer at the device side is not initialized, it may
 * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
 * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
 */
static int ufshcd_verify_dev_init(struct ufs_hba *hba)
{
        int err = 0;
        int retries;

        ufshcd_hold(hba, false);
        mutex_lock(&hba->dev_cmd.lock);
        for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
                err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
                                               NOP_OUT_TIMEOUT);

                if (!err || err == -ETIMEDOUT)
                        break;

                dev_dbg(hba->dev, "%s: error %d retrying\n", __func__, err);
        }
        mutex_unlock(&hba->dev_cmd.lock);
        ufshcd_release(hba);

        if (err)
                dev_err(hba->dev, "%s: NOP OUT failed %d\n", __func__, err);
        return err;
}

/**
 * ufshcd_set_queue_depth - set lun queue depth
 * @sdev: pointer to SCSI device
 *
 * Read bLUQueueDepth value and activate scsi tagged command
 * queueing. For WLUN, queue depth is set to 1. For best-effort
 * cases (bLUQueueDepth = 0) the queue depth is set to a maximum
 * value that host can queue.
 */
static void ufshcd_set_queue_depth(struct scsi_device *sdev)
{
        int ret = 0;
        u8 lun_qdepth;
        struct ufs_hba *hba;

        hba = shost_priv(sdev->host);

        lun_qdepth = hba->nutrs;
        ret = ufshcd_read_unit_desc_param(hba,
                                          ufshcd_scsi_to_upiu_lun(sdev->lun),
                                          UNIT_DESC_PARAM_LU_Q_DEPTH,
                                          &lun_qdepth,
                                          sizeof(lun_qdepth));

        /* Some WLUN doesn't support unit descriptor */
        if (ret == -EOPNOTSUPP)
                lun_qdepth = 1;
        else if (!lun_qdepth)
                /* eventually, we can figure out the real queue depth */
                lun_qdepth = hba->nutrs;
        else
                lun_qdepth = min_t(int, lun_qdepth, hba->nutrs);

        dev_dbg(hba->dev, "%s: activate tcq with queue depth %d\n",
                        __func__, lun_qdepth);
        scsi_activate_tcq(sdev, lun_qdepth);
}

/*
 * ufshcd_get_lu_wp - returns the "b_lu_write_protect" from UNIT DESCRIPTOR
 * @hba: per-adapter instance
 * @lun: UFS device lun id
 * @b_lu_write_protect: pointer to buffer to hold the LU's write protect info
 *
 * Returns 0 in case of success and b_lu_write_protect status would be returned
 * @b_lu_write_protect parameter.
 * Returns -ENOTSUPP if reading b_lu_write_protect is not supported.
 * Returns -EINVAL in case of invalid parameters passed to this function.
 */
static int ufshcd_get_lu_wp(struct ufs_hba *hba,
                            u8 lun,
                            u8 *b_lu_write_protect)
{
        int ret;

        if (!b_lu_write_protect)
                ret = -EINVAL;
        /*
         * According to UFS device spec, RPMB LU can't be write
         * protected so skip reading bLUWriteProtect parameter for
         * it. For other W-LUs, UNIT DESCRIPTOR is not available.
         */
        else if (lun >= UFS_UPIU_MAX_GENERAL_LUN)
                ret = -ENOTSUPP;
        else
                ret = ufshcd_read_unit_desc_param(hba,
                                          lun,
                                          UNIT_DESC_PARAM_LU_WR_PROTECT,
                                          b_lu_write_protect,
                                          sizeof(*b_lu_write_protect));
        return ret;
}

/**
 * ufshcd_get_lu_power_on_wp_status - get LU's power on write protect
 * status
 * @hba: per-adapter instance
 * @sdev: pointer to SCSI device
 *
 */
static inline void ufshcd_get_lu_power_on_wp_status(struct ufs_hba *hba,
                                                    struct scsi_device *sdev)
{
        if (hba->dev_info.f_power_on_wp_en &&
            !hba->dev_info.is_lu_power_on_wp) {
                u8 b_lu_write_protect;

                if (!ufshcd_get_lu_wp(hba, ufshcd_scsi_to_upiu_lun(sdev->lun),
                                      &b_lu_write_protect) &&
                    (b_lu_write_protect == UFS_LU_POWER_ON_WP))
                        hba->dev_info.is_lu_power_on_wp = true;
        }
}

/**
 * ufshcd_slave_alloc - handle initial SCSI device configurations
 * @sdev: pointer to SCSI device
 *
 * Returns success
 */
static int ufshcd_slave_alloc(struct scsi_device *sdev)
{
        struct ufs_hba *hba;

        hba = shost_priv(sdev->host);
        sdev->tagged_supported = 1;

        /* Mode sense(6) is not supported by UFS, so use Mode sense(10) */
        sdev->use_10_for_ms = 1;
        scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);

        /* allow SCSI layer to restart the device in case of errors */
        sdev->allow_restart = 1;

        /* REPORT SUPPORTED OPERATION CODES is not supported */
        sdev->no_report_opcodes = 1;


        ufshcd_set_queue_depth(sdev);

        ufshcd_get_lu_power_on_wp_status(hba, sdev);

        return 0;
}

/**
 * ufshcd_change_queue_depth - change queue depth
 * @sdev: pointer to SCSI device
 * @depth: required depth to set
 * @reason: reason for changing the depth
 *
 * Change queue depth according to the reason and make sure
 * the max. limits are not crossed.
 */
static int ufshcd_change_queue_depth(struct scsi_device *sdev,
                int depth, int reason)
{
        struct ufs_hba *hba = shost_priv(sdev->host);

        if (depth > hba->nutrs)
                depth = hba->nutrs;

        switch (reason) {
        case SCSI_QDEPTH_DEFAULT:
        case SCSI_QDEPTH_RAMP_UP:
                if (!sdev->tagged_supported)
                        depth = 1;
                scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
                break;
        case SCSI_QDEPTH_QFULL:
                scsi_track_queue_full(sdev, depth);
                break;
        default:
                return -EOPNOTSUPP;
        }

        return depth;
}

/**
 * ufshcd_slave_configure - adjust SCSI device configurations
 * @sdev: pointer to SCSI device
 */
static int ufshcd_slave_configure(struct scsi_device *sdev)
{
        struct request_queue *q = sdev->request_queue;

        blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
        blk_queue_max_segment_size(q, PRDT_DATA_BYTE_COUNT_MAX);

        return 0;
}

/**
 * ufshcd_slave_destroy - remove SCSI device configurations
 * @sdev: pointer to SCSI device
 */
static void ufshcd_slave_destroy(struct scsi_device *sdev)
{
        struct ufs_hba *hba;

        hba = shost_priv(sdev->host);
        scsi_deactivate_tcq(sdev, hba->nutrs);
        /* Drop the reference as it won't be needed anymore */
        if (ufshcd_scsi_to_upiu_lun(sdev->lun) == UFS_UPIU_UFS_DEVICE_WLUN)
                hba->sdev_ufs_device = NULL;
}

/**
 * ufshcd_task_req_compl - handle task management request completion
 * @hba: per adapter instance
 * @index: index of the completed request
 * @resp: task management service response
 *
 * Returns non-zero value on error, zero on success
 */
static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index, u8 *resp)
{
        struct utp_task_req_desc *task_req_descp;
        struct utp_upiu_task_rsp *task_rsp_upiup;
        unsigned long flags;
        int ocs_value;
        int task_result;

        spin_lock_irqsave(hba->host->host_lock, flags);

        /* Clear completed tasks from outstanding_tasks */
        __clear_bit(index, &hba->outstanding_tasks);

        task_req_descp = hba->utmrdl_base_addr;
        ocs_value = ufshcd_get_tmr_ocs(&task_req_descp[index]);

        if (ocs_value == OCS_SUCCESS) {
                task_rsp_upiup = (struct utp_upiu_task_rsp *)
                                task_req_descp[index].task_rsp_upiu;
                task_result = be32_to_cpu(task_rsp_upiup->header.dword_1);
                task_result = ((task_result & MASK_TASK_RESPONSE) >> 8);
                if (resp)
                        *resp = (u8)task_result;
        } else {
                dev_err(hba->dev, "%s: failed, ocs = 0x%x\n",
                                __func__, ocs_value);
        }
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        return ocs_value;
}

/**
 * ufshcd_scsi_cmd_status - Update SCSI command result based on SCSI status
 * @lrb: pointer to local reference block of completed command
 * @scsi_status: SCSI command status
 *
 * Returns value base on SCSI command status
 */
static inline int
ufshcd_scsi_cmd_status(struct ufshcd_lrb *lrbp, int scsi_status)
{
        int result = 0;

        switch (scsi_status) {
        case SAM_STAT_CHECK_CONDITION:
                ufshcd_copy_sense_data(lrbp);
        case SAM_STAT_GOOD:
                result |= DID_OK << 16 |
                          COMMAND_COMPLETE << 8 |
                          scsi_status;
                break;
        case SAM_STAT_TASK_SET_FULL:
        case SAM_STAT_BUSY:
        case SAM_STAT_TASK_ABORTED:
                ufshcd_copy_sense_data(lrbp);
                result |= scsi_status;
                break;
        default:
                result |= DID_ERROR << 16;
                break;
        } /* end of switch */

        return result;
}

/**
 * ufshcd_transfer_rsp_status - Get overall status of the response
 * @hba: per adapter instance
 * @lrb: pointer to local reference block of completed command
 *
 * Returns result of the command to notify SCSI midlayer
 */
static inline int
ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
{
        int result = 0;
        int scsi_status;
        int ocs;

        /* overall command status of utrd */
        ocs = ufshcd_get_tr_ocs(lrbp);

        switch (ocs) {
        case OCS_SUCCESS:
                result = ufshcd_get_req_rsp(lrbp->ucd_rsp_ptr);

                switch (result) {
                case UPIU_TRANSACTION_RESPONSE:
                        /*
                         * get the response UPIU result to extract
                         * the SCSI command status
                         */
                        result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);

                        /*
                         * get the result based on SCSI status response
                         * to notify the SCSI midlayer of the command status
                         */
                        scsi_status = result & MASK_SCSI_STATUS;
                        result = ufshcd_scsi_cmd_status(lrbp, scsi_status);

                        if (ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
                                schedule_work(&hba->eeh_work);
                        break;
                case UPIU_TRANSACTION_REJECT_UPIU:
                        /* TODO: handle Reject UPIU Response */
                        result = DID_ERROR << 16;
                        dev_err(hba->dev,
                                "Reject UPIU not fully implemented\n");
                        break;
                default:
                        result = DID_ERROR << 16;
                        dev_err(hba->dev,
                                "Unexpected request response code = %x\n",
                                result);
                        break;
                }
                break;
        case OCS_ABORTED:
                result |= DID_ABORT << 16;
                break;
        case OCS_INVALID_COMMAND_STATUS:
                result |= DID_REQUEUE << 16;
                break;
        case OCS_INVALID_CMD_TABLE_ATTR:
        case OCS_INVALID_PRDT_ATTR:
        case OCS_MISMATCH_DATA_BUF_SIZE:
        case OCS_MISMATCH_RESP_UPIU_SIZE:
        case OCS_PEER_COMM_FAILURE:
        case OCS_FATAL_ERROR:
        default:
                result |= DID_ERROR << 16;
                dev_err(hba->dev,
                "OCS error from controller = %x\n", ocs);
                break;
        } /* end of switch */

        return result;
}

/**
 * ufshcd_uic_cmd_compl - handle completion of uic command
 * @hba: per adapter instance
 * @intr_status: interrupt status generated by the controller
 */
static void ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
{
        if ((intr_status & UIC_COMMAND_COMPL) && hba->active_uic_cmd) {
                hba->active_uic_cmd->argument2 |=
                        ufshcd_get_uic_cmd_result(hba);
                hba->active_uic_cmd->argument3 =
                        ufshcd_get_dme_attr_val(hba);
                complete(&hba->active_uic_cmd->done);
        }

        if ((intr_status & UFSHCD_UIC_PWR_MASK) && hba->uic_async_done)
                complete(hba->uic_async_done);
}

/**
 * ufshcd_transfer_req_compl - handle SCSI and query command completion
 * @hba: per adapter instance
 */
static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
{
        struct ufshcd_lrb *lrbp;
        struct scsi_cmnd *cmd;
        unsigned long completed_reqs;
        u32 tr_doorbell;
        int result;
        int index;

        /* Resetting interrupt aggregation counters first and reading the
         * DOOR_BELL afterward allows us to handle all the completed requests.
         * In order to prevent other interrupts starvation the DB is read once
         * after reset. The down side of this solution is the possibility of
         * false interrupt if device completes another request after resetting
         * aggregation and before reading the DB.
         */
        ufshcd_reset_intr_aggr(hba);

        tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
        completed_reqs = tr_doorbell ^ hba->outstanding_reqs;

        for_each_set_bit(index, &completed_reqs, hba->nutrs) {
                lrbp = &hba->lrb[index];
                cmd = lrbp->cmd;
                if (cmd) {
                        result = ufshcd_transfer_rsp_status(hba, lrbp);
                        scsi_dma_unmap(cmd);
                        cmd->result = result;
                        /* Mark completed command as NULL in LRB */
                        lrbp->cmd = NULL;
                        clear_bit_unlock(index, &hba->lrb_in_use);
                        /* Do not touch lrbp after scsi done */
                        cmd->scsi_done(cmd);
                        __ufshcd_release(hba);
                } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE) {
                        if (hba->dev_cmd.complete)
                                complete(hba->dev_cmd.complete);
                }
        }

        /* clear corresponding bits of completed commands */
        hba->outstanding_reqs ^= completed_reqs;

        ufshcd_clk_scaling_update_busy(hba);

        /* we might have free'd some tags above */
        wake_up(&hba->dev_cmd.tag_wq);
}

/**
 * ufshcd_disable_ee - disable exception event
 * @hba: per-adapter instance
 * @mask: exception event to disable
 *
 * Disables exception event in the device so that the EVENT_ALERT
 * bit is not set.
 *
 * Returns zero on success, non-zero error value on failure.
 */
static int ufshcd_disable_ee(struct ufs_hba *hba, u16 mask)
{
        int err = 0;
        u32 val;

        if (!(hba->ee_ctrl_mask & mask))
                goto out;

        val = hba->ee_ctrl_mask & ~mask;
        val &= 0xFFFF; /* 2 bytes */
        err = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
                        QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &val);
        if (!err)
                hba->ee_ctrl_mask &= ~mask;
out:
        return err;
}

/**
 * ufshcd_enable_ee - enable exception event
 * @hba: per-adapter instance
 * @mask: exception event to enable
 *
 * Enable corresponding exception event in the device to allow
 * device to alert host in critical scenarios.
 *
 * Returns zero on success, non-zero error value on failure.
 */
static int ufshcd_enable_ee(struct ufs_hba *hba, u16 mask)
{
        int err = 0;
        u32 val;

        if (hba->ee_ctrl_mask & mask)
                goto out;

        val = hba->ee_ctrl_mask | mask;
        val &= 0xFFFF; /* 2 bytes */
        err = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
                        QUERY_ATTR_IDN_EE_CONTROL, 0, 0, &val);
        if (!err)
                hba->ee_ctrl_mask |= mask;
out:
        return err;
}

/**
 * ufshcd_enable_auto_bkops - Allow device managed BKOPS
 * @hba: per-adapter instance
 *
 * Allow device to manage background operations on its own. Enabling
 * this might lead to inconsistent latencies during normal data transfers
 * as the device is allowed to manage its own way of handling background
 * operations.
 *
 * Returns zero on success, non-zero on failure.
 */
static int ufshcd_enable_auto_bkops(struct ufs_hba *hba)
{
        int err = 0;

        if (hba->auto_bkops_enabled)
                goto out;

        err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_SET_FLAG,
                        QUERY_FLAG_IDN_BKOPS_EN, NULL);
        if (err) {
                dev_err(hba->dev, "%s: failed to enable bkops %d\n",
                                __func__, err);
                goto out;
        }

        hba->auto_bkops_enabled = true;

        /* No need of URGENT_BKOPS exception from the device */
        err = ufshcd_disable_ee(hba, MASK_EE_URGENT_BKOPS);
        if (err)
                dev_err(hba->dev, "%s: failed to disable exception event %d\n",
                                __func__, err);
out:
        return err;
}

/**
 * ufshcd_disable_auto_bkops - block device in doing background operations
 * @hba: per-adapter instance
 *
 * Disabling background operations improves command response latency but
 * has drawback of device moving into critical state where the device is
 * not-operable. Make sure to call ufshcd_enable_auto_bkops() whenever the
 * host is idle so that BKOPS are managed effectively without any negative
 * impacts.
 *
 * Returns zero on success, non-zero on failure.
 */
static int ufshcd_disable_auto_bkops(struct ufs_hba *hba)
{
        int err = 0;

        if (!hba->auto_bkops_enabled)
                goto out;

        /*
         * If host assisted BKOPs is to be enabled, make sure
         * urgent bkops exception is allowed.
         */
        err = ufshcd_enable_ee(hba, MASK_EE_URGENT_BKOPS);
        if (err) {
                dev_err(hba->dev, "%s: failed to enable exception event %d\n",
                                __func__, err);
                goto out;
        }

        err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_CLEAR_FLAG,
                        QUERY_FLAG_IDN_BKOPS_EN, NULL);
        if (err) {
                dev_err(hba->dev, "%s: failed to disable bkops %d\n",
                                __func__, err);
                ufshcd_disable_ee(hba, MASK_EE_URGENT_BKOPS);
                goto out;
        }

        hba->auto_bkops_enabled = false;
out:
        return err;
}

/**
 * ufshcd_force_reset_auto_bkops - force enable of auto bkops
 * @hba: per adapter instance
 *
 * After a device reset the device may toggle the BKOPS_EN flag
 * to default value. The s/w tracking variables should be updated
 * as well. Do this by forcing enable of auto bkops.
 */
static void  ufshcd_force_reset_auto_bkops(struct ufs_hba *hba)
{
        hba->auto_bkops_enabled = false;
        hba->ee_ctrl_mask |= MASK_EE_URGENT_BKOPS;
        ufshcd_enable_auto_bkops(hba);
}

static inline int ufshcd_get_bkops_status(struct ufs_hba *hba, u32 *status)
{
        return ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
                        QUERY_ATTR_IDN_BKOPS_STATUS, 0, 0, status);
}

/**
 * ufshcd_bkops_ctrl - control the auto bkops based on current bkops status
 * @hba: per-adapter instance
 * @status: bkops_status value
 *
 * Read the bkops_status from the UFS device and Enable fBackgroundOpsEn
 * flag in the device to permit background operations if the device
 * bkops_status is greater than or equal to "status" argument passed to
 * this function, disable otherwise.
 *
 * Returns 0 for success, non-zero in case of failure.
 *
 * NOTE: Caller of this function can check the "hba->auto_bkops_enabled" flag
 * to know whether auto bkops is enabled or disabled after this function
 * returns control to it.
 */
static int ufshcd_bkops_ctrl(struct ufs_hba *hba,
                             enum bkops_status status)
{
        int err;
        u32 curr_status = 0;

        err = ufshcd_get_bkops_status(hba, &curr_status);
        if (err) {
                dev_err(hba->dev, "%s: failed to get BKOPS status %d\n",
                                __func__, err);
                goto out;
        } else if (curr_status > BKOPS_STATUS_MAX) {
                dev_err(hba->dev, "%s: invalid BKOPS status %d\n",
                                __func__, curr_status);
                err = -EINVAL;
                goto out;
        }

        if (curr_status >= status)
                err = ufshcd_enable_auto_bkops(hba);
        else
                err = ufshcd_disable_auto_bkops(hba);
out:
        return err;
}

/**
 * ufshcd_urgent_bkops - handle urgent bkops exception event
 * @hba: per-adapter instance
 *
 * Enable fBackgroundOpsEn flag in the device to permit background
 * operations.
 *
 * If BKOPs is enabled, this function returns 0, 1 if the bkops in not enabled
 * and negative error value for any other failure.
 */
static int ufshcd_urgent_bkops(struct ufs_hba *hba)
{
        return ufshcd_bkops_ctrl(hba, BKOPS_STATUS_PERF_IMPACT);
}

static inline int ufshcd_get_ee_status(struct ufs_hba *hba, u32 *status)
{
        return ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
                        QUERY_ATTR_IDN_EE_STATUS, 0, 0, status);
}

/**
 * ufshcd_exception_event_handler - handle exceptions raised by device
 * @work: pointer to work data
 *
 * Read bExceptionEventStatus attribute from the device and handle the
 * exception event accordingly.
 */
static void ufshcd_exception_event_handler(struct work_struct *work)
{
        struct ufs_hba *hba;
        int err;
        u32 status = 0;
        hba = container_of(work, struct ufs_hba, eeh_work);

        pm_runtime_get_sync(hba->dev);
        err = ufshcd_get_ee_status(hba, &status);
        if (err) {
                dev_err(hba->dev, "%s: failed to get exception status %d\n",
                                __func__, err);
                goto out;
        }

        status &= hba->ee_ctrl_mask;
        if (status & MASK_EE_URGENT_BKOPS) {
                err = ufshcd_urgent_bkops(hba);
                if (err < 0)
                        dev_err(hba->dev, "%s: failed to handle urgent bkops %d\n",
                                        __func__, err);
        }
out:
        pm_runtime_put_sync(hba->dev);
        return;
}

/**
 * ufshcd_err_handler - handle UFS errors that require s/w attention
 * @work: pointer to work structure
 */
static void ufshcd_err_handler(struct work_struct *work)
{
        struct ufs_hba *hba;
        unsigned long flags;
        u32 err_xfer = 0;
        u32 err_tm = 0;
        int err = 0;
        int tag;

        hba = container_of(work, struct ufs_hba, eh_work);

        pm_runtime_get_sync(hba->dev);
        ufshcd_hold(hba, false);

        spin_lock_irqsave(hba->host->host_lock, flags);
        if (hba->ufshcd_state == UFSHCD_STATE_RESET) {
                spin_unlock_irqrestore(hba->host->host_lock, flags);
                goto out;
        }

        hba->ufshcd_state = UFSHCD_STATE_RESET;
        ufshcd_set_eh_in_progress(hba);

        /* Complete requests that have door-bell cleared by h/w */
        ufshcd_transfer_req_compl(hba);
        ufshcd_tmc_handler(hba);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        /* Clear pending transfer requests */
        for_each_set_bit(tag, &hba->outstanding_reqs, hba->nutrs)
                if (ufshcd_clear_cmd(hba, tag))
                        err_xfer |= 1 << tag;

        /* Clear pending task management requests */
        for_each_set_bit(tag, &hba->outstanding_tasks, hba->nutmrs)
                if (ufshcd_clear_tm_cmd(hba, tag))
                        err_tm |= 1 << tag;

        /* Complete the requests that are cleared by s/w */
        spin_lock_irqsave(hba->host->host_lock, flags);
        ufshcd_transfer_req_compl(hba);
        ufshcd_tmc_handler(hba);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        /* Fatal errors need reset */
        if (err_xfer || err_tm || (hba->saved_err & INT_FATAL_ERRORS) ||
                        ((hba->saved_err & UIC_ERROR) &&
                         (hba->saved_uic_err & UFSHCD_UIC_DL_PA_INIT_ERROR))) {
                err = ufshcd_reset_and_restore(hba);
                if (err) {
                        dev_err(hba->dev, "%s: reset and restore failed\n",
                                        __func__);
                        hba->ufshcd_state = UFSHCD_STATE_ERROR;
                }
                /*
                 * Inform scsi mid-layer that we did reset and allow to handle
                 * Unit Attention properly.
                 */
                scsi_report_bus_reset(hba->host, 0);
                hba->saved_err = 0;
                hba->saved_uic_err = 0;
        }
        ufshcd_clear_eh_in_progress(hba);

out:
        scsi_unblock_requests(hba->host);
        ufshcd_release(hba);
        pm_runtime_put_sync(hba->dev);
}

/**
 * ufshcd_update_uic_error - check and set fatal UIC error flags.
 * @hba: per-adapter instance
 */
static void ufshcd_update_uic_error(struct ufs_hba *hba)
{
        u32 reg;

        /* PA_INIT_ERROR is fatal and needs UIC reset */
        reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DATA_LINK_LAYER);
        if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
                hba->uic_error |= UFSHCD_UIC_DL_PA_INIT_ERROR;

        /* UIC NL/TL/DME errors needs software retry */
        reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_NETWORK_LAYER);
        if (reg)
                hba->uic_error |= UFSHCD_UIC_NL_ERROR;

        reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_TRANSPORT_LAYER);
        if (reg)
                hba->uic_error |= UFSHCD_UIC_TL_ERROR;

        reg = ufshcd_readl(hba, REG_UIC_ERROR_CODE_DME);
        if (reg)
                hba->uic_error |= UFSHCD_UIC_DME_ERROR;

        dev_dbg(hba->dev, "%s: UIC error flags = 0x%08x\n",
                        __func__, hba->uic_error);
}

/**
 * ufshcd_check_errors - Check for errors that need s/w attention
 * @hba: per-adapter instance
 */
static void ufshcd_check_errors(struct ufs_hba *hba)
{
        bool queue_eh_work = false;

        if (hba->errors & INT_FATAL_ERRORS)
                queue_eh_work = true;

        if (hba->errors & UIC_ERROR) {
                hba->uic_error = 0;
                ufshcd_update_uic_error(hba);
                if (hba->uic_error)
                        queue_eh_work = true;
        }

        if (queue_eh_work) {
                /* handle fatal errors only when link is functional */
                if (hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL) {
                        /* block commands from scsi mid-layer */
                        scsi_block_requests(hba->host);

                        /* transfer error masks to sticky bits */
                        hba->saved_err |= hba->errors;
                        hba->saved_uic_err |= hba->uic_error;

                        hba->ufshcd_state = UFSHCD_STATE_ERROR;
                        schedule_work(&hba->eh_work);
                }
        }
        /*
         * if (!queue_eh_work) -
         * Other errors are either non-fatal where host recovers
         * itself without s/w intervention or errors that will be
         * handled by the SCSI core layer.
         */
}

/**
 * ufshcd_tmc_handler - handle task management function completion
 * @hba: per adapter instance
 */
static void ufshcd_tmc_handler(struct ufs_hba *hba)
{
        u32 tm_doorbell;

        tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
        hba->tm_condition = tm_doorbell ^ hba->outstanding_tasks;
        wake_up(&hba->tm_wq);
}

/**
 * ufshcd_sl_intr - Interrupt service routine
 * @hba: per adapter instance
 * @intr_status: contains interrupts generated by the controller
 */
static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
{
        hba->errors = UFSHCD_ERROR_MASK & intr_status;
        if (hba->errors)
                ufshcd_check_errors(hba);

        if (intr_status & UFSHCD_UIC_MASK)
                ufshcd_uic_cmd_compl(hba, intr_status);

        if (intr_status & UTP_TASK_REQ_COMPL)
                ufshcd_tmc_handler(hba);

        if (intr_status & UTP_TRANSFER_REQ_COMPL)
                ufshcd_transfer_req_compl(hba);
}

/**
 * ufshcd_intr - Main interrupt service routine
 * @irq: irq number
 * @__hba: pointer to adapter instance
 *
 * Returns IRQ_HANDLED - If interrupt is valid
 *              IRQ_NONE - If invalid interrupt
 */
static irqreturn_t ufshcd_intr(int irq, void *__hba)
{
        u32 intr_status;
        irqreturn_t retval = IRQ_NONE;
        struct ufs_hba *hba = __hba;

        spin_lock(hba->host->host_lock);
        intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);

        if (intr_status) {
                ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS);
                ufshcd_sl_intr(hba, intr_status);
                retval = IRQ_HANDLED;
        }
        spin_unlock(hba->host->host_lock);
        return retval;
}

static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag)
{
        int err = 0;
        u32 mask = 1 << tag;
        unsigned long flags;

        if (!test_bit(tag, &hba->outstanding_tasks))
                goto out;

        spin_lock_irqsave(hba->host->host_lock, flags);
        ufshcd_writel(hba, ~(1 << tag), REG_UTP_TASK_REQ_LIST_CLEAR);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        /* poll for max. 1 sec to clear door bell register by h/w */
        err = ufshcd_wait_for_register(hba,
                        REG_UTP_TASK_REQ_DOOR_BELL,
                        mask, 0, 1000, 1000);
out:
        return err;
}

/**
 * ufshcd_issue_tm_cmd - issues task management commands to controller
 * @hba: per adapter instance
 * @lun_id: LUN ID to which TM command is sent
 * @task_id: task ID to which the TM command is applicable
 * @tm_function: task management function opcode
 * @tm_response: task management service response return value
 *
 * Returns non-zero value on error, zero on success.
 */
static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id,
                u8 tm_function, u8 *tm_response)
{
        struct utp_task_req_desc *task_req_descp;
        struct utp_upiu_task_req *task_req_upiup;
        struct Scsi_Host *host;
        unsigned long flags;
        int free_slot;
        int err;
        int task_tag;

        host = hba->host;

        /*
         * Get free slot, sleep if slots are unavailable.
         * Even though we use wait_event() which sleeps indefinitely,
         * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
         */
        wait_event(hba->tm_tag_wq, ufshcd_get_tm_free_slot(hba, &free_slot));
        ufshcd_hold(hba, false);

        spin_lock_irqsave(host->host_lock, flags);
        task_req_descp = hba->utmrdl_base_addr;
        task_req_descp += free_slot;

        /* Configure task request descriptor */
        task_req_descp->header.dword_0 = cpu_to_le32(UTP_REQ_DESC_INT_CMD);
        task_req_descp->header.dword_2 =
                        cpu_to_le32(OCS_INVALID_COMMAND_STATUS);

        /* Configure task request UPIU */
        task_req_upiup =
                (struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
        task_tag = hba->nutrs + free_slot;
        task_req_upiup->header.dword_0 =
                UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
                                              lun_id, task_tag);
        task_req_upiup->header.dword_1 =
                UPIU_HEADER_DWORD(0, tm_function, 0, 0);
        /*
         * The host shall provide the same value for LUN field in the basic
         * header and for Input Parameter.
         */
        task_req_upiup->input_param1 = cpu_to_be32(lun_id);
        task_req_upiup->input_param2 = cpu_to_be32(task_id);

        /* send command to the controller */
        __set_bit(free_slot, &hba->outstanding_tasks);
        ufshcd_writel(hba, 1 << free_slot, REG_UTP_TASK_REQ_DOOR_BELL);

        spin_unlock_irqrestore(host->host_lock, flags);

        /* wait until the task management command is completed */
        err = wait_event_timeout(hba->tm_wq,
                        test_bit(free_slot, &hba->tm_condition),
                        msecs_to_jiffies(TM_CMD_TIMEOUT));
        if (!err) {
                dev_err(hba->dev, "%s: task management cmd 0x%.2x timed-out\n",
                                __func__, tm_function);
                if (ufshcd_clear_tm_cmd(hba, free_slot))
                        dev_WARN(hba->dev, "%s: unable clear tm cmd (slot %d) after timeout\n",
                                        __func__, free_slot);
                err = -ETIMEDOUT;
        } else {
                err = ufshcd_task_req_compl(hba, free_slot, tm_response);
        }

        clear_bit(free_slot, &hba->tm_condition);
        ufshcd_put_tm_slot(hba, free_slot);
        wake_up(&hba->tm_tag_wq);

        ufshcd_release(hba);
        return err;
}

/**
 * ufshcd_eh_device_reset_handler - device reset handler registered to
 *                                    scsi layer.
 * @cmd: SCSI command pointer
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_eh_device_reset_handler(struct scsi_cmnd *cmd)
{
        struct Scsi_Host *host;
        struct ufs_hba *hba;
        unsigned int tag;
        u32 pos;
        int err;
        u8 resp = 0xF;
        struct ufshcd_lrb *lrbp;
        unsigned long flags;

        host = cmd->device->host;
        hba = shost_priv(host);
        tag = cmd->request->tag;

        lrbp = &hba->lrb[tag];
        err = ufshcd_issue_tm_cmd(hba, lrbp->lun, 0, UFS_LOGICAL_RESET, &resp);
        if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
                if (!err)
                        err = resp;
                goto out;
        }

        /* clear the commands that were pending for corresponding LUN */
        for_each_set_bit(pos, &hba->outstanding_reqs, hba->nutrs) {
                if (hba->lrb[pos].lun == lrbp->lun) {
                        err = ufshcd_clear_cmd(hba, pos);
                        if (err)
                                break;
                }
        }
        spin_lock_irqsave(host->host_lock, flags);
        ufshcd_transfer_req_compl(hba);
        spin_unlock_irqrestore(host->host_lock, flags);
out:
        if (!err) {
                err = SUCCESS;
        } else {
                dev_err(hba->dev, "%s: failed with err %d\n", __func__, err);
                err = FAILED;
        }
        return err;
}

/**
 * ufshcd_abort - abort a specific command
 * @cmd: SCSI command pointer
 *
 * Abort the pending command in device by sending UFS_ABORT_TASK task management
 * command, and in host controller by clearing the door-bell register. There can
 * be race between controller sending the command to the device while abort is
 * issued. To avoid that, first issue UFS_QUERY_TASK to check if the command is
 * really issued and then try to abort it.
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_abort(struct scsi_cmnd *cmd)
{
        struct Scsi_Host *host;
        struct ufs_hba *hba;
        unsigned long flags;
        unsigned int tag;
        int err = 0;
        int poll_cnt;
        u8 resp = 0xF;
        struct ufshcd_lrb *lrbp;
        u32 reg;

        host = cmd->device->host;
        hba = shost_priv(host);
        tag = cmd->request->tag;

        ufshcd_hold(hba, false);
        /* If command is already aborted/completed, return SUCCESS */
        if (!(test_bit(tag, &hba->outstanding_reqs)))
                goto out;

        reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
        if (!(reg & (1 << tag))) {
                dev_err(hba->dev,
                "%s: cmd was completed, but without a notifying intr, tag = %d",
                __func__, tag);
        }

        lrbp = &hba->lrb[tag];
        for (poll_cnt = 100; poll_cnt; poll_cnt--) {
                err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
                                UFS_QUERY_TASK, &resp);
                if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_SUCCEEDED) {
                        /* cmd pending in the device */
                        break;
                } else if (!err && resp == UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
                        /*
                         * cmd not pending in the device, check if it is
                         * in transition.
                         */
                        reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
                        if (reg & (1 << tag)) {
                                /* sleep for max. 200us to stabilize */
                                usleep_range(100, 200);
                                continue;
                        }
                        /* command completed already */
                        goto out;
                } else {
                        if (!err)
                                err = resp; /* service response error */
                        goto out;
                }
        }

        if (!poll_cnt) {
                err = -EBUSY;
                goto out;
        }

        err = ufshcd_issue_tm_cmd(hba, lrbp->lun, lrbp->task_tag,
                        UFS_ABORT_TASK, &resp);
        if (err || resp != UPIU_TASK_MANAGEMENT_FUNC_COMPL) {
                if (!err)
                        err = resp; /* service response error */
                goto out;
        }

        err = ufshcd_clear_cmd(hba, tag);
        if (err)
                goto out;

        scsi_dma_unmap(cmd);

        spin_lock_irqsave(host->host_lock, flags);
        __clear_bit(tag, &hba->outstanding_reqs);
        hba->lrb[tag].cmd = NULL;
        spin_unlock_irqrestore(host->host_lock, flags);

        clear_bit_unlock(tag, &hba->lrb_in_use);
        wake_up(&hba->dev_cmd.tag_wq);

out:
        if (!err) {
                err = SUCCESS;
        } else {
                dev_err(hba->dev, "%s: failed with err %d\n", __func__, err);
                err = FAILED;
        }

        /*
         * This ufshcd_release() corresponds to the original scsi cmd that got
         * aborted here (as we won't get any IRQ for it).
         */
        ufshcd_release(hba);
        return err;
}

/**
 * ufshcd_host_reset_and_restore - reset and restore host controller
 * @hba: per-adapter instance
 *
 * Note that host controller reset may issue DME_RESET to
 * local and remote (device) Uni-Pro stack and the attributes
 * are reset to default state.
 *
 * Returns zero on success, non-zero on failure
 */
static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
{
        int err;
        unsigned long flags;

        /* Reset the host controller */
        spin_lock_irqsave(hba->host->host_lock, flags);
        ufshcd_hba_stop(hba);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        err = ufshcd_hba_enable(hba);
        if (err)
                goto out;

        /* Establish the link again and restore the device */
        err = ufshcd_probe_hba(hba);

        if (!err && (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL))
                err = -EIO;
out:
        if (err)
                dev_err(hba->dev, "%s: Host init failed %d\n", __func__, err);

        return err;
}

/**
 * ufshcd_reset_and_restore - reset and re-initialize host/device
 * @hba: per-adapter instance
 *
 * Reset and recover device, host and re-establish link. This
 * is helpful to recover the communication in fatal error conditions.
 *
 * Returns zero on success, non-zero on failure
 */
static int ufshcd_reset_and_restore(struct ufs_hba *hba)
{
        int err = 0;
        unsigned long flags;
        int retries = MAX_HOST_RESET_RETRIES;

        do {
                err = ufshcd_host_reset_and_restore(hba);
        } while (err && --retries);

        /*
         * After reset the door-bell might be cleared, complete
         * outstanding requests in s/w here.
         */
        spin_lock_irqsave(hba->host->host_lock, flags);
        ufshcd_transfer_req_compl(hba);
        ufshcd_tmc_handler(hba);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        return err;
}

/**
 * ufshcd_eh_host_reset_handler - host reset handler registered to scsi layer
 * @cmd - SCSI command pointer
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_eh_host_reset_handler(struct scsi_cmnd *cmd)
{
        int err;
        unsigned long flags;
        struct ufs_hba *hba;

        hba = shost_priv(cmd->device->host);

        ufshcd_hold(hba, false);
        /*
         * Check if there is any race with fatal error handling.
         * If so, wait for it to complete. Even though fatal error
         * handling does reset and restore in some cases, don't assume
         * anything out of it. We are just avoiding race here.
         */
        do {
                spin_lock_irqsave(hba->host->host_lock, flags);
                if (!(work_pending(&hba->eh_work) ||
                                hba->ufshcd_state == UFSHCD_STATE_RESET))
                        break;
                spin_unlock_irqrestore(hba->host->host_lock, flags);
                dev_dbg(hba->dev, "%s: reset in progress\n", __func__);
                flush_work(&hba->eh_work);
        } while (1);

        hba->ufshcd_state = UFSHCD_STATE_RESET;
        ufshcd_set_eh_in_progress(hba);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        err = ufshcd_reset_and_restore(hba);

        spin_lock_irqsave(hba->host->host_lock, flags);
        if (!err) {
                err = SUCCESS;
                hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
        } else {
                err = FAILED;
                hba->ufshcd_state = UFSHCD_STATE_ERROR;
        }
        ufshcd_clear_eh_in_progress(hba);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        ufshcd_release(hba);
        return err;
}

/**
 * ufshcd_get_max_icc_level - calculate the ICC level
 * @sup_curr_uA: max. current supported by the regulator
 * @start_scan: row at the desc table to start scan from
 * @buff: power descriptor buffer
 *
 * Returns calculated max ICC level for specific regulator
 */
static u32 ufshcd_get_max_icc_level(int sup_curr_uA, u32 start_scan, char *buff)
{
        int i;
        int curr_uA;
        u16 data;
        u16 unit;

        for (i = start_scan; i >= 0; i--) {
                data = be16_to_cpu(*((u16 *)(buff + 2*i)));
                unit = (data & ATTR_ICC_LVL_UNIT_MASK) >>
                                                ATTR_ICC_LVL_UNIT_OFFSET;
                curr_uA = data & ATTR_ICC_LVL_VALUE_MASK;
                switch (unit) {
                case UFSHCD_NANO_AMP:
                        curr_uA = curr_uA / 1000;
                        break;
                case UFSHCD_MILI_AMP:
                        curr_uA = curr_uA * 1000;
                        break;
                case UFSHCD_AMP:
                        curr_uA = curr_uA * 1000 * 1000;
                        break;
                case UFSHCD_MICRO_AMP:
                default:
                        break;
                }
                if (sup_curr_uA >= curr_uA)
                        break;
        }
        if (i < 0) {
                i = 0;
                pr_err("%s: Couldn't find valid icc_level = %d", __func__, i);
        }

        return (u32)i;
}

/**
 * ufshcd_calc_icc_level - calculate the max ICC level
 * In case regulators are not initialized we'll return 0
 * @hba: per-adapter instance
 * @desc_buf: power descriptor buffer to extract ICC levels from.
 * @len: length of desc_buff
 *
 * Returns calculated ICC level
 */
static u32 ufshcd_find_max_sup_active_icc_level(struct ufs_hba *hba,
                                                        u8 *desc_buf, int len)
{
        u32 icc_level = 0;

        if (!hba->vreg_info.vcc || !hba->vreg_info.vccq ||
                                                !hba->vreg_info.vccq2) {
                dev_err(hba->dev,
                        "%s: Regulator capability was not set, actvIccLevel=%d",
                                                        __func__, icc_level);
                goto out;
        }

        if (hba->vreg_info.vcc)
                icc_level = ufshcd_get_max_icc_level(
                                hba->vreg_info.vcc->max_uA,
                                POWER_DESC_MAX_ACTV_ICC_LVLS - 1,
                                &desc_buf[PWR_DESC_ACTIVE_LVLS_VCC_0]);

        if (hba->vreg_info.vccq)
                icc_level = ufshcd_get_max_icc_level(
                                hba->vreg_info.vccq->max_uA,
                                icc_level,
                                &desc_buf[PWR_DESC_ACTIVE_LVLS_VCCQ_0]);

        if (hba->vreg_info.vccq2)
                icc_level = ufshcd_get_max_icc_level(
                                hba->vreg_info.vccq2->max_uA,
                                icc_level,
                                &desc_buf[PWR_DESC_ACTIVE_LVLS_VCCQ2_0]);
out:
        return icc_level;
}

static void ufshcd_init_icc_levels(struct ufs_hba *hba)
{
        int ret;
        int buff_len = QUERY_DESC_POWER_MAX_SIZE;
        u8 desc_buf[QUERY_DESC_POWER_MAX_SIZE];

        ret = ufshcd_read_power_desc(hba, desc_buf, buff_len);
        if (ret) {
                dev_err(hba->dev,
                        "%s: Failed reading power descriptor.len = %d ret = %d",
                        __func__, buff_len, ret);
                return;
        }

        hba->init_prefetch_data.icc_level =
                        ufshcd_find_max_sup_active_icc_level(hba,
                        desc_buf, buff_len);
        dev_dbg(hba->dev, "%s: setting icc_level 0x%x",
                        __func__, hba->init_prefetch_data.icc_level);

        ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
                        QUERY_ATTR_IDN_ACTIVE_ICC_LVL, 0, 0,
                        &hba->init_prefetch_data.icc_level);

        if (ret)
                dev_err(hba->dev,
                        "%s: Failed configuring bActiveICCLevel = %d ret = %d",
                        __func__, hba->init_prefetch_data.icc_level , ret);

}

/**
 * ufshcd_scsi_add_wlus - Adds required W-LUs
 * @hba: per-adapter instance
 *
 * UFS device specification requires the UFS devices to support 4 well known
 * logical units:
 *      "REPORT_LUNS" (address: 01h)
 *      "UFS Device" (address: 50h)
 *      "RPMB" (address: 44h)
 *      "BOOT" (address: 30h)
 * UFS device's power management needs to be controlled by "POWER CONDITION"
 * field of SSU (START STOP UNIT) command. But this "power condition" field
 * will take effect only when its sent to "UFS device" well known logical unit
 * hence we require the scsi_device instance to represent this logical unit in
 * order for the UFS host driver to send the SSU command for power management.

 * We also require the scsi_device instance for "RPMB" (Replay Protected Memory
 * Block) LU so user space process can control this LU. User space may also
 * want to have access to BOOT LU.

 * This function adds scsi device instances for each of all well known LUs
 * (except "REPORT LUNS" LU).
 *
 * Returns zero on success (all required W-LUs are added successfully),
 * non-zero error value on failure (if failed to add any of the required W-LU).
 */
static int ufshcd_scsi_add_wlus(struct ufs_hba *hba)
{
        int ret = 0;

        hba->sdev_ufs_device = __scsi_add_device(hba->host, 0, 0,
                ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN), NULL);
        if (IS_ERR(hba->sdev_ufs_device)) {
                ret = PTR_ERR(hba->sdev_ufs_device);
                hba->sdev_ufs_device = NULL;
                goto out;
        }

        hba->sdev_boot = __scsi_add_device(hba->host, 0, 0,
                ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_BOOT_WLUN), NULL);
        if (IS_ERR(hba->sdev_boot)) {
                ret = PTR_ERR(hba->sdev_boot);
                hba->sdev_boot = NULL;
                goto remove_sdev_ufs_device;
        }

        hba->sdev_rpmb = __scsi_add_device(hba->host, 0, 0,
                ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN), NULL);
        if (IS_ERR(hba->sdev_rpmb)) {
                ret = PTR_ERR(hba->sdev_rpmb);
                hba->sdev_rpmb = NULL;
                goto remove_sdev_boot;
        }
        goto out;

remove_sdev_boot:
        scsi_remove_device(hba->sdev_boot);
remove_sdev_ufs_device:
        scsi_remove_device(hba->sdev_ufs_device);
out:
        return ret;
}

/**
 * ufshcd_scsi_remove_wlus - Removes the W-LUs which were added by
 *                           ufshcd_scsi_add_wlus()
 * @hba: per-adapter instance
 *
 */
static void ufshcd_scsi_remove_wlus(struct ufs_hba *hba)
{
        if (hba->sdev_ufs_device) {
                scsi_remove_device(hba->sdev_ufs_device);
                hba->sdev_ufs_device = NULL;
        }

        if (hba->sdev_boot) {
                scsi_remove_device(hba->sdev_boot);
                hba->sdev_boot = NULL;
        }

        if (hba->sdev_rpmb) {
                scsi_remove_device(hba->sdev_rpmb);
                hba->sdev_rpmb = NULL;
        }
}

/**
 * ufshcd_probe_hba - probe hba to detect device and initialize
 * @hba: per-adapter instance
 *
 * Execute link-startup and verify device initialization
 */
static int ufshcd_probe_hba(struct ufs_hba *hba)
{
        int ret;

        ret = ufshcd_link_startup(hba);
        if (ret)
                goto out;

        /* UniPro link is active now */
        ufshcd_set_link_active(hba);

        ret = ufshcd_verify_dev_init(hba);
        if (ret)
                goto out;

        ret = ufshcd_complete_dev_init(hba);
        if (ret)
                goto out;

        /* UFS device is also active now */
        ufshcd_set_ufs_dev_active(hba);
        ufshcd_force_reset_auto_bkops(hba);
        hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
        hba->wlun_dev_clr_ua = true;

        if (ufshcd_get_max_pwr_mode(hba)) {
                dev_err(hba->dev,
                        "%s: Failed getting max supported power mode\n",
                        __func__);
        } else {
                ret = ufshcd_config_pwr_mode(hba, &hba->max_pwr_info.info);
                if (ret)
                        dev_err(hba->dev, "%s: Failed setting power mode, err = %d\n",
                                        __func__, ret);
        }

        /*
         * If we are in error handling context or in power management callbacks
         * context, no need to scan the host
         */
        if (!ufshcd_eh_in_progress(hba) && !hba->pm_op_in_progress) {
                bool flag;

                /* clear any previous UFS device information */
                memset(&hba->dev_info, 0, sizeof(hba->dev_info));
                if (!ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG,
                                       QUERY_FLAG_IDN_PWR_ON_WPE, &flag))
                        hba->dev_info.f_power_on_wp_en = flag;

                if (!hba->is_init_prefetch)
                        ufshcd_init_icc_levels(hba);

                /* Add required well known logical units to scsi mid layer */
                if (ufshcd_scsi_add_wlus(hba))
                        goto out;

                scsi_scan_host(hba->host);
                pm_runtime_put_sync(hba->dev);
        }

        if (!hba->is_init_prefetch)
                hba->is_init_prefetch = true;

        /* Resume devfreq after UFS device is detected */
        if (ufshcd_is_clkscaling_enabled(hba))
                devfreq_resume_device(hba->devfreq);

out:
        /*
         * If we failed to initialize the device or the device is not
         * present, turn off the power/clocks etc.
         */
        if (ret && !ufshcd_eh_in_progress(hba) && !hba->pm_op_in_progress) {
                pm_runtime_put_sync(hba->dev);
                ufshcd_hba_exit(hba);
        }

        return ret;
}

/**
 * ufshcd_async_scan - asynchronous execution for probing hba
 * @data: data pointer to pass to this function
 * @cookie: cookie data
 */
static void ufshcd_async_scan(void *data, async_cookie_t cookie)
{
        struct ufs_hba *hba = (struct ufs_hba *)data;

        ufshcd_probe_hba(hba);
}

static struct scsi_host_template ufshcd_driver_template = {
        .module                 = THIS_MODULE,
        .name                   = UFSHCD,
        .proc_name              = UFSHCD,
        .queuecommand           = ufshcd_queuecommand,
        .slave_alloc            = ufshcd_slave_alloc,
        .slave_configure        = ufshcd_slave_configure,
        .slave_destroy          = ufshcd_slave_destroy,
        .change_queue_depth     = ufshcd_change_queue_depth,
        .eh_abort_handler       = ufshcd_abort,
        .eh_device_reset_handler = ufshcd_eh_device_reset_handler,
        .eh_host_reset_handler   = ufshcd_eh_host_reset_handler,
        .this_id                = -1,
        .sg_tablesize           = SG_ALL,
        .cmd_per_lun            = UFSHCD_CMD_PER_LUN,
        .can_queue              = UFSHCD_CAN_QUEUE,
        .max_host_blocked       = 1,
};

static int ufshcd_config_vreg_load(struct device *dev, struct ufs_vreg *vreg,
                                   int ua)
{
        int ret = 0;
        struct regulator *reg = vreg->reg;
        const char *name = vreg->name;

        BUG_ON(!vreg);

        ret = regulator_set_optimum_mode(reg, ua);
        if (ret >= 0) {
                /*
                 * regulator_set_optimum_mode() returns new regulator
                 * mode upon success.
                 */
                ret = 0;
        } else {
                dev_err(dev, "%s: %s set optimum mode(ua=%d) failed, err=%d\n",
                                __func__, name, ua, ret);
        }

        return ret;
}

static inline int ufshcd_config_vreg_lpm(struct ufs_hba *hba,
                                         struct ufs_vreg *vreg)
{
        return ufshcd_config_vreg_load(hba->dev, vreg, UFS_VREG_LPM_LOAD_UA);
}

static inline int ufshcd_config_vreg_hpm(struct ufs_hba *hba,
                                         struct ufs_vreg *vreg)
{
        return ufshcd_config_vreg_load(hba->dev, vreg, vreg->max_uA);
}

static int ufshcd_config_vreg(struct device *dev,
                struct ufs_vreg *vreg, bool on)
{
        int ret = 0;
        struct regulator *reg = vreg->reg;
        const char *name = vreg->name;
        int min_uV, uA_load;

        BUG_ON(!vreg);

        if (regulator_count_voltages(reg) > 0) {
                min_uV = on ? vreg->min_uV : 0;
                ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);
                if (ret) {
                        dev_err(dev, "%s: %s set voltage failed, err=%d\n",
                                        __func__, name, ret);
                        goto out;
                }

                uA_load = on ? vreg->max_uA : 0;
                ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
                if (ret)
                        goto out;
        }
out:
        return ret;
}

static int ufshcd_enable_vreg(struct device *dev, struct ufs_vreg *vreg)
{
        int ret = 0;

        if (!vreg || vreg->enabled)
                goto out;

        ret = ufshcd_config_vreg(dev, vreg, true);
        if (!ret)
                ret = regulator_enable(vreg->reg);

        if (!ret)
                vreg->enabled = true;
        else
                dev_err(dev, "%s: %s enable failed, err=%d\n",
                                __func__, vreg->name, ret);
out:
        return ret;
}

static int ufshcd_disable_vreg(struct device *dev, struct ufs_vreg *vreg)
{
        int ret = 0;

        if (!vreg || !vreg->enabled)
                goto out;

        ret = regulator_disable(vreg->reg);

        if (!ret) {
                /* ignore errors on applying disable config */
                ufshcd_config_vreg(dev, vreg, false);
                vreg->enabled = false;
        } else {
                dev_err(dev, "%s: %s disable failed, err=%d\n",
                                __func__, vreg->name, ret);
        }
out:
        return ret;
}

static int ufshcd_setup_vreg(struct ufs_hba *hba, bool on)
{
        int ret = 0;
        struct device *dev = hba->dev;
        struct ufs_vreg_info *info = &hba->vreg_info;

        if (!info)
                goto out;

        ret = ufshcd_toggle_vreg(dev, info->vcc, on);
        if (ret)
                goto out;

        ret = ufshcd_toggle_vreg(dev, info->vccq, on);
        if (ret)
                goto out;

        ret = ufshcd_toggle_vreg(dev, info->vccq2, on);
        if (ret)
                goto out;

out:
        if (ret) {
                ufshcd_toggle_vreg(dev, info->vccq2, false);
                ufshcd_toggle_vreg(dev, info->vccq, false);
                ufshcd_toggle_vreg(dev, info->vcc, false);
        }
        return ret;
}

static int ufshcd_setup_hba_vreg(struct ufs_hba *hba, bool on)
{
        struct ufs_vreg_info *info = &hba->vreg_info;

        if (info)
                return ufshcd_toggle_vreg(hba->dev, info->vdd_hba, on);

        return 0;
}

static int ufshcd_get_vreg(struct device *dev, struct ufs_vreg *vreg)
{
        int ret = 0;

        if (!vreg)
                goto out;

        vreg->reg = devm_regulator_get(dev, vreg->name);
        if (IS_ERR(vreg->reg)) {
                ret = PTR_ERR(vreg->reg);
                dev_err(dev, "%s: %s get failed, err=%d\n",
                                __func__, vreg->name, ret);
        }
out:
        return ret;
}

static int ufshcd_init_vreg(struct ufs_hba *hba)
{
        int ret = 0;
        struct device *dev = hba->dev;
        struct ufs_vreg_info *info = &hba->vreg_info;

        if (!info)
                goto out;

        ret = ufshcd_get_vreg(dev, info->vcc);
        if (ret)
                goto out;

        ret = ufshcd_get_vreg(dev, info->vccq);
        if (ret)
                goto out;

        ret = ufshcd_get_vreg(dev, info->vccq2);
out:
        return ret;
}

static int ufshcd_init_hba_vreg(struct ufs_hba *hba)
{
        struct ufs_vreg_info *info = &hba->vreg_info;

        if (info)
                return ufshcd_get_vreg(hba->dev, info->vdd_hba);

        return 0;
}

static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
                                        bool skip_ref_clk)
{
        int ret = 0;
        struct ufs_clk_info *clki;
        struct list_head *head = &hba->clk_list_head;
        unsigned long flags;

        if (!head || list_empty(head))
                goto out;

        list_for_each_entry(clki, head, list) {
                if (!IS_ERR_OR_NULL(clki->clk)) {
                        if (skip_ref_clk && !strcmp(clki->name, "ref_clk"))
                                continue;

                        if (on && !clki->enabled) {
                                ret = clk_prepare_enable(clki->clk);
                                if (ret) {
                                        dev_err(hba->dev, "%s: %s prepare enable failed, %d\n",
                                                __func__, clki->name, ret);
                                        goto out;
                                }
                        } else if (!on && clki->enabled) {
                                clk_disable_unprepare(clki->clk);
                        }
                        clki->enabled = on;
                        dev_dbg(hba->dev, "%s: clk: %s %sabled\n", __func__,
                                        clki->name, on ? "en" : "dis");
                }
        }

        if (hba->vops && hba->vops->setup_clocks)
                ret = hba->vops->setup_clocks(hba, on);
out:
        if (ret) {
                list_for_each_entry(clki, head, list) {
                        if (!IS_ERR_OR_NULL(clki->clk) && clki->enabled)
                                clk_disable_unprepare(clki->clk);
                }
        } else if (!ret && on) {
                spin_lock_irqsave(hba->host->host_lock, flags);
                hba->clk_gating.state = CLKS_ON;
                spin_unlock_irqrestore(hba->host->host_lock, flags);
        }
        return ret;
}

static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on)
{
        return  __ufshcd_setup_clocks(hba, on, false);
}

static int ufshcd_init_clocks(struct ufs_hba *hba)
{
        int ret = 0;
        struct ufs_clk_info *clki;
        struct device *dev = hba->dev;
        struct list_head *head = &hba->clk_list_head;

        if (!head || list_empty(head))
                goto out;

        list_for_each_entry(clki, head, list) {
                if (!clki->name)
                        continue;

                clki->clk = devm_clk_get(dev, clki->name);
                if (IS_ERR(clki->clk)) {
                        ret = PTR_ERR(clki->clk);
                        dev_err(dev, "%s: %s clk get failed, %d\n",
                                        __func__, clki->name, ret);
                        goto out;
                }

                if (clki->max_freq) {
                        ret = clk_set_rate(clki->clk, clki->max_freq);
                        if (ret) {
                                dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
                                        __func__, clki->name,
                                        clki->max_freq, ret);
                                goto out;
                        }
                        clki->curr_freq = clki->max_freq;
                }
                dev_dbg(dev, "%s: clk: %s, rate: %lu\n", __func__,
                                clki->name, clk_get_rate(clki->clk));
        }
out:
        return ret;
}

static int ufshcd_variant_hba_init(struct ufs_hba *hba)
{
        int err = 0;

        if (!hba->vops)
                goto out;

        if (hba->vops->init) {
                err = hba->vops->init(hba);
                if (err)
                        goto out;
        }

        if (hba->vops->setup_regulators) {
                err = hba->vops->setup_regulators(hba, true);
                if (err)
                        goto out_exit;
        }

        goto out;

out_exit:
        if (hba->vops->exit)
                hba->vops->exit(hba);
out:
        if (err)
                dev_err(hba->dev, "%s: variant %s init failed err %d\n",
                        __func__, hba->vops ? hba->vops->name : "", err);
        return err;
}

static void ufshcd_variant_hba_exit(struct ufs_hba *hba)
{
        if (!hba->vops)
                return;

        if (hba->vops->setup_clocks)
                hba->vops->setup_clocks(hba, false);

        if (hba->vops->setup_regulators)
                hba->vops->setup_regulators(hba, false);

        if (hba->vops->exit)
                hba->vops->exit(hba);
}

static int ufshcd_hba_init(struct ufs_hba *hba)
{
        int err;

        /*
         * Handle host controller power separately from the UFS device power
         * rails as it will help controlling the UFS host controller power
         * collapse easily which is different than UFS device power collapse.
         * Also, enable the host controller power before we go ahead with rest
         * of the initialization here.
         */
        err = ufshcd_init_hba_vreg(hba);
        if (err)
                goto out;

        err = ufshcd_setup_hba_vreg(hba, true);
        if (err)
                goto out;

        err = ufshcd_init_clocks(hba);
        if (err)
                goto out_disable_hba_vreg;

        err = ufshcd_setup_clocks(hba, true);
        if (err)
                goto out_disable_hba_vreg;

        err = ufshcd_init_vreg(hba);
        if (err)
                goto out_disable_clks;

        err = ufshcd_setup_vreg(hba, true);
        if (err)
                goto out_disable_clks;

        err = ufshcd_variant_hba_init(hba);
        if (err)
                goto out_disable_vreg;

        hba->is_powered = true;
        goto out;

out_disable_vreg:
        ufshcd_setup_vreg(hba, false);
out_disable_clks:
        ufshcd_setup_clocks(hba, false);
out_disable_hba_vreg:
        ufshcd_setup_hba_vreg(hba, false);
out:
        return err;
}

static void ufshcd_hba_exit(struct ufs_hba *hba)
{
        if (hba->is_powered) {
                ufshcd_variant_hba_exit(hba);
                ufshcd_setup_vreg(hba, false);
                ufshcd_setup_clocks(hba, false);
                ufshcd_setup_hba_vreg(hba, false);
                hba->is_powered = false;
        }
}

static int
ufshcd_send_request_sense(struct ufs_hba *hba, struct scsi_device *sdp)
{
        unsigned char cmd[6] = {REQUEST_SENSE,
                                0,
                                0,
                                0,
                                SCSI_SENSE_BUFFERSIZE,
                                0};
        char *buffer;
        int ret;

        buffer = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
        if (!buffer) {
                ret = -ENOMEM;
                goto out;
        }

        ret = scsi_execute_req_flags(sdp, cmd, DMA_FROM_DEVICE, buffer,
                                SCSI_SENSE_BUFFERSIZE, NULL,
                                msecs_to_jiffies(1000), 3, NULL, REQ_PM);
        if (ret)
                pr_err("%s: failed with err %d\n", __func__, ret);

        kfree(buffer);
out:
        return ret;
}

/**
 * ufshcd_set_dev_pwr_mode - sends START STOP UNIT command to set device
 *                           power mode
 * @hba: per adapter instance
 * @pwr_mode: device power mode to set
 *
 * Returns 0 if requested power mode is set successfully
 * Returns non-zero if failed to set the requested power mode
 */
static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
                                     enum ufs_dev_pwr_mode pwr_mode)
{
        unsigned char cmd[6] = { START_STOP };
        struct scsi_sense_hdr sshdr;
        struct scsi_device *sdp = hba->sdev_ufs_device;
        int ret;

        if (!sdp || !scsi_device_online(sdp))
                return -ENODEV;

        /*
         * If scsi commands fail, the scsi mid-layer schedules scsi error-
         * handling, which would wait for host to be resumed. Since we know
         * we are functional while we are here, skip host resume in error
         * handling context.
         */
        hba->host->eh_noresume = 1;
        if (hba->wlun_dev_clr_ua) {
                ret = ufshcd_send_request_sense(hba, sdp);
                if (ret)
                        goto out;
                /* Unit attention condition is cleared now */
                hba->wlun_dev_clr_ua = false;
        }

        cmd[4] = pwr_mode << 4;

        /*
         * Current function would be generally called from the power management
         * callbacks hence set the REQ_PM flag so that it doesn't resume the
         * already suspended childs.
         */
        ret = scsi_execute_req_flags(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
                                     START_STOP_TIMEOUT, 0, NULL, REQ_PM);
        if (ret) {
                sdev_printk(KERN_WARNING, sdp,
                          "START_STOP failed for power mode: %d\n", pwr_mode);
                scsi_show_result(ret);
                if (driver_byte(ret) & DRIVER_SENSE) {
                        scsi_show_sense_hdr(&sshdr);
                        scsi_show_extd_sense(sshdr.asc, sshdr.ascq);
                }
        }

        if (!ret)
                hba->curr_dev_pwr_mode = pwr_mode;
out:
        hba->host->eh_noresume = 0;
        return ret;
}

static int ufshcd_link_state_transition(struct ufs_hba *hba,
                                        enum uic_link_state req_link_state,
                                        int check_for_bkops)
{
        int ret = 0;

        if (req_link_state == hba->uic_link_state)
                return 0;

        if (req_link_state == UIC_LINK_HIBERN8_STATE) {
                ret = ufshcd_uic_hibern8_enter(hba);
                if (!ret)
                        ufshcd_set_link_hibern8(hba);
                else
                        goto out;
        }
        /*
         * If autobkops is enabled, link can't be turned off because
         * turning off the link would also turn off the device.
         */
        else if ((req_link_state == UIC_LINK_OFF_STATE) &&
                   (!check_for_bkops || (check_for_bkops &&
                    !hba->auto_bkops_enabled))) {
                /*
                 * Change controller state to "reset state" which
                 * should also put the link in off/reset state
                 */
                ufshcd_hba_stop(hba);
                /*
                 * TODO: Check if we need any delay to make sure that
                 * controller is reset
                 */
                ufshcd_set_link_off(hba);
        }

out:
        return ret;
}

static void ufshcd_vreg_set_lpm(struct ufs_hba *hba)
{
        /*
         * If UFS device is either in UFS_Sleep turn off VCC rail to save some
         * power.
         *
         * If UFS device and link is in OFF state, all power supplies (VCC,
         * VCCQ, VCCQ2) can be turned off if power on write protect is not
         * required. If UFS link is inactive (Hibern8 or OFF state) and device
         * is in sleep state, put VCCQ & VCCQ2 rails in LPM mode.
         *
         * Ignore the error returned by ufshcd_toggle_vreg() as device is anyway
         * in low power state which would save some power.
         */
        if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba) &&
            !hba->dev_info.is_lu_power_on_wp) {
                ufshcd_setup_vreg(hba, false);
        } else if (!ufshcd_is_ufs_dev_active(hba)) {
                ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false);
                if (!ufshcd_is_link_active(hba)) {
                        ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq);
                        ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2);
                }
        }
}

static int ufshcd_vreg_set_hpm(struct ufs_hba *hba)
{
        int ret = 0;

        if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba) &&
            !hba->dev_info.is_lu_power_on_wp) {
                ret = ufshcd_setup_vreg(hba, true);
        } else if (!ufshcd_is_ufs_dev_active(hba)) {
                ret = ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, true);
                if (!ret && !ufshcd_is_link_active(hba)) {
                        ret = ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq);
                        if (ret)
                                goto vcc_disable;
                        ret = ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq2);
                        if (ret)
                                goto vccq_lpm;
                }
        }
        goto out;

vccq_lpm:
        ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq);
vcc_disable:
        ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false);
out:
        return ret;
}

static void ufshcd_hba_vreg_set_lpm(struct ufs_hba *hba)
{
        if (ufshcd_is_link_off(hba))
                ufshcd_setup_hba_vreg(hba, false);
}

static void ufshcd_hba_vreg_set_hpm(struct ufs_hba *hba)
{
        if (ufshcd_is_link_off(hba))
                ufshcd_setup_hba_vreg(hba, true);
}

/**
 * ufshcd_suspend - helper function for suspend operations
 * @hba: per adapter instance
 * @pm_op: desired low power operation type
 *
 * This function will try to put the UFS device and link into low power
 * mode based on the "rpm_lvl" (Runtime PM level) or "spm_lvl"
 * (System PM level).
 *
 * If this function is called during shutdown, it will make sure that
 * both UFS device and UFS link is powered off.
 *
 * NOTE: UFS device & link must be active before we enter in this function.
 *
 * Returns 0 for success and non-zero for failure
 */
static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
{
        int ret = 0;
        enum ufs_pm_level pm_lvl;
        enum ufs_dev_pwr_mode req_dev_pwr_mode;
        enum uic_link_state req_link_state;

        hba->pm_op_in_progress = 1;
        if (!ufshcd_is_shutdown_pm(pm_op)) {
                pm_lvl = ufshcd_is_runtime_pm(pm_op) ?
                         hba->rpm_lvl : hba->spm_lvl;
                req_dev_pwr_mode = ufs_get_pm_lvl_to_dev_pwr_mode(pm_lvl);
                req_link_state = ufs_get_pm_lvl_to_link_pwr_state(pm_lvl);
        } else {
                req_dev_pwr_mode = UFS_POWERDOWN_PWR_MODE;
                req_link_state = UIC_LINK_OFF_STATE;
        }

        /*
         * If we can't transition into any of the low power modes
         * just gate the clocks.
         */
        ufshcd_hold(hba, false);
        hba->clk_gating.is_suspended = true;

        if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
                        req_link_state == UIC_LINK_ACTIVE_STATE) {
                goto disable_clks;
        }

        if ((req_dev_pwr_mode == hba->curr_dev_pwr_mode) &&
            (req_link_state == hba->uic_link_state))
                goto out;

        /* UFS device & link must be active before we enter in this function */
        if (!ufshcd_is_ufs_dev_active(hba) || !ufshcd_is_link_active(hba)) {
                ret = -EINVAL;
                goto out;
        }

        if (ufshcd_is_runtime_pm(pm_op)) {
                if (ufshcd_can_autobkops_during_suspend(hba)) {
                        /*
                         * The device is idle with no requests in the queue,
                         * allow background operations if bkops status shows
                         * that performance might be impacted.
                         */
                        ret = ufshcd_urgent_bkops(hba);
                        if (ret)
                                goto enable_gating;
                } else {
                        /* make sure that auto bkops is disabled */
                        ufshcd_disable_auto_bkops(hba);
                }
        }

        if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) &&
             ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) ||
               !ufshcd_is_runtime_pm(pm_op))) {
                /* ensure that bkops is disabled */
                ufshcd_disable_auto_bkops(hba);
                ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode);
                if (ret)
                        goto enable_gating;
        }

        ret = ufshcd_link_state_transition(hba, req_link_state, 1);
        if (ret)
                goto set_dev_active;

        ufshcd_vreg_set_lpm(hba);

disable_clks:
        /*
         * The clock scaling needs access to controller registers. Hence, Wait
         * for pending clock scaling work to be done before clocks are
         * turned off.
         */
        if (ufshcd_is_clkscaling_enabled(hba)) {
                devfreq_suspend_device(hba->devfreq);
                hba->clk_scaling.window_start_t = 0;
        }
        /*
         * Call vendor specific suspend callback. As these callbacks may access
         * vendor specific host controller register space call them before the
         * host clocks are ON.
         */
        if (hba->vops && hba->vops->suspend) {
                ret = hba->vops->suspend(hba, pm_op);
                if (ret)
                        goto set_link_active;
        }

        if (hba->vops && hba->vops->setup_clocks) {
                ret = hba->vops->setup_clocks(hba, false);
                if (ret)
                        goto vops_resume;
        }

        if (!ufshcd_is_link_active(hba))
                ufshcd_setup_clocks(hba, false);
        else
                /* If link is active, device ref_clk can't be switched off */
                __ufshcd_setup_clocks(hba, false, true);

        hba->clk_gating.state = CLKS_OFF;
        /*
         * Disable the host irq as host controller as there won't be any
         * host controller trasanction expected till resume.
         */
        ufshcd_disable_irq(hba);
        /* Put the host controller in low power mode if possible */
        ufshcd_hba_vreg_set_lpm(hba);
        goto out;

vops_resume:
        if (hba->vops && hba->vops->resume)
                hba->vops->resume(hba, pm_op);
set_link_active:
        ufshcd_vreg_set_hpm(hba);
        if (ufshcd_is_link_hibern8(hba) && !ufshcd_uic_hibern8_exit(hba))
                ufshcd_set_link_active(hba);
        else if (ufshcd_is_link_off(hba))
                ufshcd_host_reset_and_restore(hba);
set_dev_active:
        if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
                ufshcd_disable_auto_bkops(hba);
enable_gating:
        hba->clk_gating.is_suspended = false;
        ufshcd_release(hba);
out:
        hba->pm_op_in_progress = 0;
        return ret;
}

/**
 * ufshcd_resume - helper function for resume operations
 * @hba: per adapter instance
 * @pm_op: runtime PM or system PM
 *
 * This function basically brings the UFS device, UniPro link and controller
 * to active state.
 *
 * Returns 0 for success and non-zero for failure
 */
static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
{
        int ret;
        enum uic_link_state old_link_state;

        hba->pm_op_in_progress = 1;
        old_link_state = hba->uic_link_state;

        ufshcd_hba_vreg_set_hpm(hba);
        /* Make sure clocks are enabled before accessing controller */
        ret = ufshcd_setup_clocks(hba, true);
        if (ret)
                goto out;

        /* enable the host irq as host controller would be active soon */
        ret = ufshcd_enable_irq(hba);
        if (ret)
                goto disable_irq_and_vops_clks;

        ret = ufshcd_vreg_set_hpm(hba);
        if (ret)
                goto disable_irq_and_vops_clks;

        /*
         * Call vendor specific resume callback. As these callbacks may access
         * vendor specific host controller register space call them when the
         * host clocks are ON.
         */
        if (hba->vops && hba->vops->resume) {
                ret = hba->vops->resume(hba, pm_op);
                if (ret)
                        goto disable_vreg;
        }

        if (ufshcd_is_link_hibern8(hba)) {
                ret = ufshcd_uic_hibern8_exit(hba);
                if (!ret)
                        ufshcd_set_link_active(hba);
                else
                        goto vendor_suspend;
        } else if (ufshcd_is_link_off(hba)) {
                ret = ufshcd_host_reset_and_restore(hba);
                /*
                 * ufshcd_host_reset_and_restore() should have already
                 * set the link state as active
                 */
                if (ret || !ufshcd_is_link_active(hba))
                        goto vendor_suspend;
        }

        if (!ufshcd_is_ufs_dev_active(hba)) {
                ret = ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE);
                if (ret)
                        goto set_old_link_state;
        }

        /*
         * If BKOPs operations are urgently needed at this moment then
         * keep auto-bkops enabled or else disable it.
         */
        ufshcd_urgent_bkops(hba);
        hba->clk_gating.is_suspended = false;

        if (ufshcd_is_clkscaling_enabled(hba))
                devfreq_resume_device(hba->devfreq);

        /* Schedule clock gating in case of no access to UFS device yet */
        ufshcd_release(hba);
        goto out;

set_old_link_state:
        ufshcd_link_state_transition(hba, old_link_state, 0);
vendor_suspend:
        if (hba->vops && hba->vops->suspend)
                hba->vops->suspend(hba, pm_op);
disable_vreg:
        ufshcd_vreg_set_lpm(hba);
disable_irq_and_vops_clks:
        ufshcd_disable_irq(hba);
        ufshcd_setup_clocks(hba, false);
out:
        hba->pm_op_in_progress = 0;
        return ret;
}

/**
 * ufshcd_system_suspend - system suspend routine
 * @hba: per adapter instance
 * @pm_op: runtime PM or system PM
 *
 * Check the description of ufshcd_suspend() function for more details.
 *
 * Returns 0 for success and non-zero for failure
 */
int ufshcd_system_suspend(struct ufs_hba *hba)
{
        int ret = 0;

        if (!hba || !hba->is_powered)
                goto out;

        if (pm_runtime_suspended(hba->dev)) {
                if (hba->rpm_lvl == hba->spm_lvl)
                        /*
                         * There is possibility that device may still be in
                         * active state during the runtime suspend.
                         */
                        if ((ufs_get_pm_lvl_to_dev_pwr_mode(hba->spm_lvl) ==
                            hba->curr_dev_pwr_mode) && !hba->auto_bkops_enabled)
                                goto out;

                /*
                 * UFS device and/or UFS link low power states during runtime
                 * suspend seems to be different than what is expected during
                 * system suspend. Hence runtime resume the devic & link and
                 * let the system suspend low power states to take effect.
                 * TODO: If resume takes longer time, we might have optimize
                 * it in future by not resuming everything if possible.
                 */
                ret = ufshcd_runtime_resume(hba);
                if (ret)
                        goto out;
        }

        ret = ufshcd_suspend(hba, UFS_SYSTEM_PM);
out:
        if (!ret)
                hba->is_sys_suspended = true;
        return ret;
}
EXPORT_SYMBOL(ufshcd_system_suspend);

/**
 * ufshcd_system_resume - system resume routine
 * @hba: per adapter instance
 *
 * Returns 0 for success and non-zero for failure
 */

int ufshcd_system_resume(struct ufs_hba *hba)
{
        if (!hba || !hba->is_powered || pm_runtime_suspended(hba->dev))
                /*
                 * Let the runtime resume take care of resuming
                 * if runtime suspended.
                 */
                return 0;

        return ufshcd_resume(hba, UFS_SYSTEM_PM);
}
EXPORT_SYMBOL(ufshcd_system_resume);

/**
 * ufshcd_runtime_suspend - runtime suspend routine
 * @hba: per adapter instance
 *
 * Check the description of ufshcd_suspend() function for more details.
 *
 * Returns 0 for success and non-zero for failure
 */
int ufshcd_runtime_suspend(struct ufs_hba *hba)
{
        if (!hba || !hba->is_powered)
                return 0;

        return ufshcd_suspend(hba, UFS_RUNTIME_PM);
}
EXPORT_SYMBOL(ufshcd_runtime_suspend);

/**
 * ufshcd_runtime_resume - runtime resume routine
 * @hba: per adapter instance
 *
 * This function basically brings the UFS device, UniPro link and controller
 * to active state. Following operations are done in this function:
 *
 * 1. Turn on all the controller related clocks
 * 2. Bring the UniPro link out of Hibernate state
 * 3. If UFS device is in sleep state, turn ON VCC rail and bring the UFS device
 *    to active state.
 * 4. If auto-bkops is enabled on the device, disable it.
 *
 * So following would be the possible power state after this function return
 * successfully:
 *      S1: UFS device in Active state with VCC rail ON
 *          UniPro link in Active state
 *          All the UFS/UniPro controller clocks are ON
 *
 * Returns 0 for success and non-zero for failure
 */
int ufshcd_runtime_resume(struct ufs_hba *hba)
{
        if (!hba || !hba->is_powered)
                return 0;
        else
                return ufshcd_resume(hba, UFS_RUNTIME_PM);
}
EXPORT_SYMBOL(ufshcd_runtime_resume);

int ufshcd_runtime_idle(struct ufs_hba *hba)
{
        return 0;
}
EXPORT_SYMBOL(ufshcd_runtime_idle);

/**
 * ufshcd_shutdown - shutdown routine
 * @hba: per adapter instance
 *
 * This function would power off both UFS device and UFS link.
 *
 * Returns 0 always to allow force shutdown even in case of errors.
 */
int ufshcd_shutdown(struct ufs_hba *hba)
{
        int ret = 0;

        if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba))
                goto out;

        if (pm_runtime_suspended(hba->dev)) {
                ret = ufshcd_runtime_resume(hba);
                if (ret)
                        goto out;
        }

        ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
out:
        if (ret)
                dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
        /* allow force shutdown even in case of errors */
        return 0;
}
EXPORT_SYMBOL(ufshcd_shutdown);

/**
 * ufshcd_remove - de-allocate SCSI host and host memory space
 *              data structure memory
 * @hba - per adapter instance
 */
void ufshcd_remove(struct ufs_hba *hba)
{
        scsi_remove_host(hba->host);
        ufshcd_scsi_remove_wlus(hba);
        /* disable interrupts */
        ufshcd_disable_intr(hba, hba->intr_mask);
        ufshcd_hba_stop(hba);

        scsi_host_put(hba->host);

        ufshcd_exit_clk_gating(hba);
        if (ufshcd_is_clkscaling_enabled(hba))
                devfreq_remove_device(hba->devfreq);
        ufshcd_hba_exit(hba);
}
EXPORT_SYMBOL_GPL(ufshcd_remove);

/**
 * ufshcd_set_dma_mask - Set dma mask based on the controller
 *                       addressing capability
 * @hba: per adapter instance
 *
 * Returns 0 for success, non-zero for failure
 */
static int ufshcd_set_dma_mask(struct ufs_hba *hba)
{
        if (hba->capabilities & MASK_64_ADDRESSING_SUPPORT) {
                if (!dma_set_mask_and_coherent(hba->dev, DMA_BIT_MASK(64)))
                        return 0;
        }
        return dma_set_mask_and_coherent(hba->dev, DMA_BIT_MASK(32));
}

/**
 * ufshcd_alloc_host - allocate Host Bus Adapter (HBA)
 * @dev: pointer to device handle
 * @hba_handle: driver private handle
 * Returns 0 on success, non-zero value on failure
 */
int ufshcd_alloc_host(struct device *dev, struct ufs_hba **hba_handle)
{
        struct Scsi_Host *host;
        struct ufs_hba *hba;
        int err = 0;

        if (!dev) {
                dev_err(dev,
                "Invalid memory reference for dev is NULL\n");
                err = -ENODEV;
                goto out_error;
        }

        host = scsi_host_alloc(&ufshcd_driver_template,
                                sizeof(struct ufs_hba));
        if (!host) {
                dev_err(dev, "scsi_host_alloc failed\n");
                err = -ENOMEM;
                goto out_error;
        }
        hba = shost_priv(host);
        hba->host = host;
        hba->dev = dev;
        *hba_handle = hba;

out_error:
        return err;
}
EXPORT_SYMBOL(ufshcd_alloc_host);

static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up)
{
        int ret = 0;
        struct ufs_clk_info *clki;
        struct list_head *head = &hba->clk_list_head;

        if (!head || list_empty(head))
                goto out;

        list_for_each_entry(clki, head, list) {
                if (!IS_ERR_OR_NULL(clki->clk)) {
                        if (scale_up && clki->max_freq) {
                                if (clki->curr_freq == clki->max_freq)
                                        continue;
                                ret = clk_set_rate(clki->clk, clki->max_freq);
                                if (ret) {
                                        dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
                                                __func__, clki->name,
                                                clki->max_freq, ret);
                                        break;
                                }
                                clki->curr_freq = clki->max_freq;

                        } else if (!scale_up && clki->min_freq) {
                                if (clki->curr_freq == clki->min_freq)
                                        continue;
                                ret = clk_set_rate(clki->clk, clki->min_freq);
                                if (ret) {
                                        dev_err(hba->dev, "%s: %s clk set rate(%dHz) failed, %d\n",
                                                __func__, clki->name,
                                                clki->min_freq, ret);
                                        break;
                                }
                                clki->curr_freq = clki->min_freq;
                        }
                }
                dev_dbg(hba->dev, "%s: clk: %s, rate: %lu\n", __func__,
                                clki->name, clk_get_rate(clki->clk));
        }
        if (hba->vops->clk_scale_notify)
                hba->vops->clk_scale_notify(hba);
out:
        return ret;
}

static int ufshcd_devfreq_target(struct device *dev,
                                unsigned long *freq, u32 flags)
{
        int err = 0;
        struct ufs_hba *hba = dev_get_drvdata(dev);

        if (!ufshcd_is_clkscaling_enabled(hba))
                return -EINVAL;

        if (*freq == UINT_MAX)
                err = ufshcd_scale_clks(hba, true);
        else if (*freq == 0)
                err = ufshcd_scale_clks(hba, false);

        return err;
}

static int ufshcd_devfreq_get_dev_status(struct device *dev,
                struct devfreq_dev_status *stat)
{
        struct ufs_hba *hba = dev_get_drvdata(dev);
        struct ufs_clk_scaling *scaling = &hba->clk_scaling;
        unsigned long flags;

        if (!ufshcd_is_clkscaling_enabled(hba))
                return -EINVAL;

        memset(stat, 0, sizeof(*stat));

        spin_lock_irqsave(hba->host->host_lock, flags);
        if (!scaling->window_start_t)
                goto start_window;

        if (scaling->is_busy_started)
                scaling->tot_busy_t += ktime_to_us(ktime_sub(ktime_get(),
                                        scaling->busy_start_t));

        stat->total_time = jiffies_to_usecs((long)jiffies -
                                (long)scaling->window_start_t);
        stat->busy_time = scaling->tot_busy_t;
start_window:
        scaling->window_start_t = jiffies;
        scaling->tot_busy_t = 0;

        if (hba->outstanding_reqs) {
                scaling->busy_start_t = ktime_get();
                scaling->is_busy_started = true;
        } else {
                scaling->busy_start_t = ktime_set(0, 0);
                scaling->is_busy_started = false;
        }
        spin_unlock_irqrestore(hba->host->host_lock, flags);
        return 0;
}

static struct devfreq_dev_profile ufs_devfreq_profile = {
        .polling_ms     = 100,
        .target         = ufshcd_devfreq_target,
        .get_dev_status = ufshcd_devfreq_get_dev_status,
};

/**
 * ufshcd_init - Driver initialization routine
 * @hba: per-adapter instance
 * @mmio_base: base register address
 * @irq: Interrupt line of device
 * Returns 0 on success, non-zero value on failure
 */
int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
{
        int err;
        struct Scsi_Host *host = hba->host;
        struct device *dev = hba->dev;

        if (!mmio_base) {
                dev_err(hba->dev,
                "Invalid memory reference for mmio_base is NULL\n");
                err = -ENODEV;
                goto out_error;
        }

        hba->mmio_base = mmio_base;
        hba->irq = irq;

        err = ufshcd_hba_init(hba);
        if (err)
                goto out_error;

        /* Read capabilities registers */
        ufshcd_hba_capabilities(hba);

        /* Get UFS version supported by the controller */
        hba->ufs_version = ufshcd_get_ufs_version(hba);

        /* Get Interrupt bit mask per version */
        hba->intr_mask = ufshcd_get_intr_mask(hba);

        err = ufshcd_set_dma_mask(hba);
        if (err) {
                dev_err(hba->dev, "set dma mask failed\n");
                goto out_disable;
        }

        /* Allocate memory for host memory space */
        err = ufshcd_memory_alloc(hba);
        if (err) {
                dev_err(hba->dev, "Memory allocation failed\n");
                goto out_disable;
        }

        /* Configure LRB */
        ufshcd_host_memory_configure(hba);

        host->can_queue = hba->nutrs;
        host->cmd_per_lun = hba->nutrs;
        host->max_id = UFSHCD_MAX_ID;
        host->max_lun = UFS_MAX_LUNS;
        host->max_channel = UFSHCD_MAX_CHANNEL;
        host->unique_id = host->host_no;
        host->max_cmd_len = MAX_CDB_SIZE;

        hba->max_pwr_info.is_valid = false;

        /* Initailize wait queue for task management */
        init_waitqueue_head(&hba->tm_wq);
        init_waitqueue_head(&hba->tm_tag_wq);

        /* Initialize work queues */
        INIT_WORK(&hba->eh_work, ufshcd_err_handler);
        INIT_WORK(&hba->eeh_work, ufshcd_exception_event_handler);

        /* Initialize UIC command mutex */
        mutex_init(&hba->uic_cmd_mutex);

        /* Initialize mutex for device management commands */
        mutex_init(&hba->dev_cmd.lock);

        /* Initialize device management tag acquire wait queue */
        init_waitqueue_head(&hba->dev_cmd.tag_wq);

        ufshcd_init_clk_gating(hba);
        /* IRQ registration */
        err = devm_request_irq(dev, irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
        if (err) {
                dev_err(hba->dev, "request irq failed\n");
                goto exit_gating;
        } else {
                hba->is_irq_enabled = true;
        }

        /* Enable SCSI tag mapping */
        err = scsi_init_shared_tag_map(host, host->can_queue);
        if (err) {
                dev_err(hba->dev, "init shared queue failed\n");
                goto exit_gating;
        }

        err = scsi_add_host(host, hba->dev);
        if (err) {
                dev_err(hba->dev, "scsi_add_host failed\n");
                goto exit_gating;
        }

        /* Host controller enable */
        err = ufshcd_hba_enable(hba);
        if (err) {
                dev_err(hba->dev, "Host controller enable failed\n");
                goto out_remove_scsi_host;
        }

        if (ufshcd_is_clkscaling_enabled(hba)) {
                hba->devfreq = devfreq_add_device(dev, &ufs_devfreq_profile,
                                                   "simple_ondemand", NULL);
                if (IS_ERR(hba->devfreq)) {
                        dev_err(hba->dev, "Unable to register with devfreq %ld\n",
                                        PTR_ERR(hba->devfreq));
                        goto out_remove_scsi_host;
                }
                /* Suspend devfreq until the UFS device is detected */
                devfreq_suspend_device(hba->devfreq);
                hba->clk_scaling.window_start_t = 0;
        }

        /* Hold auto suspend until async scan completes */
        pm_runtime_get_sync(dev);

        /*
         * The device-initialize-sequence hasn't been invoked yet.
         * Set the device to power-off state
         */
        ufshcd_set_ufs_dev_poweroff(hba);

        async_schedule(ufshcd_async_scan, hba);

        return 0;

out_remove_scsi_host:
        scsi_remove_host(hba->host);
exit_gating:
        ufshcd_exit_clk_gating(hba);
out_disable:
        hba->is_irq_enabled = false;
        scsi_host_put(host);
        ufshcd_hba_exit(hba);
out_error:
        return err;
}
EXPORT_SYMBOL_GPL(ufshcd_init);

MODULE_AUTHOR("Santosh Yaragnavi <santosh.sy@samsung.com>");
MODULE_AUTHOR("Vinayak Holikatti <h.vinayak@samsung.com>");
MODULE_DESCRIPTION("Generic UFS host controller driver Core");
MODULE_LICENSE("GPL");
MODULE_VERSION(UFSHCD_DRIVER_VERSION);