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) 2013-2016, 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 <linux/nls.h>
#include <linux/of.h>
#include <linux/bitfield.h>
#include "ufshcd.h"
#include "ufs_quirks.h"
#include "unipro.h"
#include "ufs-sysfs.h"
#include "ufs_bsg.h"

#define CREATE_TRACE_POINTS
#include <trace/events/ufs.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 3
/* Query request timeout */
#define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */

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

/* maximum number of retries for a general UIC command  */
#define UFS_UIC_COMMAND_RETRIES 3

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

/* Maximum retries for Hibern8 enter */
#define UIC_HIBERN8_ENTER_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;                                                   \
	})

#define ufshcd_hex_dump(prefix_str, buf, len) do {                       \
	size_t __len = (len);                                            \
	print_hex_dump(KERN_ERR, prefix_str,                             \
		       __len > 4 ? DUMP_PREFIX_OFFSET : DUMP_PREFIX_NONE,\
		       16, 4, buf, __len, false);                        \
} while (0)

int ufshcd_dump_regs(struct ufs_hba *hba, size_t offset, size_t len,
		     const char *prefix)
{
	u32 *regs;
	size_t pos;

	if (offset % 4 != 0 || len % 4 != 0) /* keep readl happy */
		return -EINVAL;

	regs = kzalloc(len, GFP_KERNEL);
	if (!regs)
		return -ENOMEM;

	for (pos = 0; pos < len; pos += 4)
		regs[pos / 4] = ufshcd_readl(hba, offset + pos);

	ufshcd_hex_dump(prefix, regs, len);
	kfree(regs);

	return 0;
}
EXPORT_SYMBOL_GPL(ufshcd_dump_regs);

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_STATE_EH_SCHEDULED,
};

/* 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_DL_NAC_RECEIVED_ERROR = (1 << 1), /* Data link layer error */
	UFSHCD_UIC_DL_TCx_REPLAY_ERROR = (1 << 2), /* Data link layer error */
	UFSHCD_UIC_NL_ERROR = (1 << 3), /* Network layer error */
	UFSHCD_UIC_TL_ERROR = (1 << 4), /* Transport Layer error */
	UFSHCD_UIC_DME_ERROR = (1 << 5), /* DME error */
};

#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)

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 inline enum ufs_pm_level
ufs_get_desired_pm_lvl_for_dev_link_state(enum ufs_dev_pwr_mode dev_state,
					enum uic_link_state link_state)
{
	enum ufs_pm_level lvl;

	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++) {
		if ((ufs_pm_lvl_states[lvl].dev_state == dev_state) &&
			(ufs_pm_lvl_states[lvl].link_state == link_state))
			return lvl;
	}

	/* if no match found, return the level 0 */
	return UFS_PM_LVL_0;
}

static struct ufs_dev_fix ufs_fixups[] = {
	/* UFS cards deviations table */
	UFS_FIX(UFS_VENDOR_SAMSUNG, UFS_ANY_MODEL,
		UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM),
	UFS_FIX(UFS_VENDOR_SAMSUNG, UFS_ANY_MODEL,
		UFS_DEVICE_QUIRK_RECOVERY_FROM_DL_NAC_ERRORS),
	UFS_FIX(UFS_VENDOR_SAMSUNG, UFS_ANY_MODEL,
		UFS_DEVICE_QUIRK_HOST_PA_TACTIVATE),
	UFS_FIX(UFS_VENDOR_TOSHIBA, UFS_ANY_MODEL,
		UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM),
	UFS_FIX(UFS_VENDOR_TOSHIBA, "THGLF2G9C8KBADG",
		UFS_DEVICE_QUIRK_PA_TACTIVATE),
	UFS_FIX(UFS_VENDOR_TOSHIBA, "THGLF2G9D8KBADG",
		UFS_DEVICE_QUIRK_PA_TACTIVATE),
	UFS_FIX(UFS_VENDOR_SKHYNIX, UFS_ANY_MODEL,
		UFS_DEVICE_QUIRK_HOST_PA_SAVECONFIGTIME),
	UFS_FIX(UFS_VENDOR_SKHYNIX, "hB8aL1" /*H28U62301AMR*/,
		UFS_DEVICE_QUIRK_HOST_VS_DEBUGSAVECONFIGTIME),

	END_FIX
};

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_eh_host_reset_handler(struct scsi_cmnd *cmd);
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 inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba);
static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
static void ufshcd_resume_clkscaling(struct ufs_hba *hba);
static void ufshcd_suspend_clkscaling(struct ufs_hba *hba);
static void __ufshcd_suspend_clkscaling(struct ufs_hba *hba);
static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up);
static irqreturn_t ufshcd_intr(int irq, void *__hba);
static int ufshcd_change_power_mode(struct ufs_hba *hba,
			     struct ufs_pa_layer_attr *pwr_mode);
static inline bool ufshcd_valid_tag(struct ufs_hba *hba, int tag)
{
	return tag >= 0 && tag < hba->nutrs;
}

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;
	}
}

static void ufshcd_scsi_unblock_requests(struct ufs_hba *hba)
{
	if (atomic_dec_and_test(&hba->scsi_block_reqs_cnt))
		scsi_unblock_requests(hba->host);
}

static void ufshcd_scsi_block_requests(struct ufs_hba *hba)
{
	if (atomic_inc_return(&hba->scsi_block_reqs_cnt) == 1)
		scsi_block_requests(hba->host);
}

/* replace non-printable or non-ASCII characters with spaces */
static inline void ufshcd_remove_non_printable(char *val)
{
	if (!val)
		return;

	if (*val < 0x20 || *val > 0x7e)
		*val = ' ';
}

static void ufshcd_add_cmd_upiu_trace(struct ufs_hba *hba, unsigned int tag,
		const char *str)
{
	struct utp_upiu_req *rq = hba->lrb[tag].ucd_req_ptr;

	trace_ufshcd_upiu(dev_name(hba->dev), str, &rq->header, &rq->sc.cdb);
}

static void ufshcd_add_query_upiu_trace(struct ufs_hba *hba, unsigned int tag,
		const char *str)
{
	struct utp_upiu_req *rq = hba->lrb[tag].ucd_req_ptr;

	trace_ufshcd_upiu(dev_name(hba->dev), str, &rq->header, &rq->qr);
}

static void ufshcd_add_tm_upiu_trace(struct ufs_hba *hba, unsigned int tag,
		const char *str)
{
	int off = (int)tag - hba->nutrs;
	struct utp_task_req_desc *descp = &hba->utmrdl_base_addr[off];

	trace_ufshcd_upiu(dev_name(hba->dev), str, &descp->req_header,
			&descp->input_param1);
}

static void ufshcd_add_command_trace(struct ufs_hba *hba,
		unsigned int tag, const char *str)
{
	sector_t lba = -1;
	u8 opcode = 0;
	u32 intr, doorbell;
	struct ufshcd_lrb *lrbp = &hba->lrb[tag];
	int transfer_len = -1;

	if (!trace_ufshcd_command_enabled()) {
		/* trace UPIU W/O tracing command */
		if (lrbp->cmd)
			ufshcd_add_cmd_upiu_trace(hba, tag, str);
		return;
	}

	if (lrbp->cmd) { /* data phase exists */
		/* trace UPIU also */
		ufshcd_add_cmd_upiu_trace(hba, tag, str);
		opcode = (u8)(*lrbp->cmd->cmnd);
		if ((opcode == READ_10) || (opcode == WRITE_10)) {
			/*
			 * Currently we only fully trace read(10) and write(10)
			 * commands
			 */
			if (lrbp->cmd->request && lrbp->cmd->request->bio)
				lba =
				  lrbp->cmd->request->bio->bi_iter.bi_sector;
			transfer_len = be32_to_cpu(
				lrbp->ucd_req_ptr->sc.exp_data_transfer_len);
		}
	}

	intr = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
	doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
	trace_ufshcd_command(dev_name(hba->dev), str, tag,
				doorbell, transfer_len, intr, lba, opcode);
}

static void ufshcd_print_clk_freqs(struct ufs_hba *hba)
{
	struct ufs_clk_info *clki;
	struct list_head *head = &hba->clk_list_head;

	if (list_empty(head))
		return;

	list_for_each_entry(clki, head, list) {
		if (!IS_ERR_OR_NULL(clki->clk) && clki->min_freq &&
				clki->max_freq)
			dev_err(hba->dev, "clk: %s, rate: %u\n",
					clki->name, clki->curr_freq);
	}
}

static void ufshcd_print_uic_err_hist(struct ufs_hba *hba,
		struct ufs_uic_err_reg_hist *err_hist, char *err_name)
{
	int i;
	bool found = false;

	for (i = 0; i < UIC_ERR_REG_HIST_LENGTH; i++) {
		int p = (i + err_hist->pos) % UIC_ERR_REG_HIST_LENGTH;

		if (err_hist->reg[p] == 0)
			continue;
		dev_err(hba->dev, "%s[%d] = 0x%x at %lld us\n", err_name, i,
			err_hist->reg[p], ktime_to_us(err_hist->tstamp[p]));
		found = true;
	}

	if (!found)
		dev_err(hba->dev, "No record of %s uic errors\n", err_name);
}

static void ufshcd_print_host_regs(struct ufs_hba *hba)
{
	ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
	dev_err(hba->dev, "hba->ufs_version = 0x%x, hba->capabilities = 0x%x\n",
		hba->ufs_version, hba->capabilities);
	dev_err(hba->dev,
		"hba->outstanding_reqs = 0x%x, hba->outstanding_tasks = 0x%x\n",
		(u32)hba->outstanding_reqs, (u32)hba->outstanding_tasks);
	dev_err(hba->dev,
		"last_hibern8_exit_tstamp at %lld us, hibern8_exit_cnt = %d\n",
		ktime_to_us(hba->ufs_stats.last_hibern8_exit_tstamp),
		hba->ufs_stats.hibern8_exit_cnt);

	ufshcd_print_uic_err_hist(hba, &hba->ufs_stats.pa_err, "pa_err");
	ufshcd_print_uic_err_hist(hba, &hba->ufs_stats.dl_err, "dl_err");
	ufshcd_print_uic_err_hist(hba, &hba->ufs_stats.nl_err, "nl_err");
	ufshcd_print_uic_err_hist(hba, &hba->ufs_stats.tl_err, "tl_err");
	ufshcd_print_uic_err_hist(hba, &hba->ufs_stats.dme_err, "dme_err");

	ufshcd_print_clk_freqs(hba);

	if (hba->vops && hba->vops->dbg_register_dump)
		hba->vops->dbg_register_dump(hba);
}

static
void ufshcd_print_trs(struct ufs_hba *hba, unsigned long bitmap, bool pr_prdt)
{
	struct ufshcd_lrb *lrbp;
	int prdt_length;
	int tag;

	for_each_set_bit(tag, &bitmap, hba->nutrs) {
		lrbp = &hba->lrb[tag];

		dev_err(hba->dev, "UPIU[%d] - issue time %lld us\n",
				tag, ktime_to_us(lrbp->issue_time_stamp));
		dev_err(hba->dev, "UPIU[%d] - complete time %lld us\n",
				tag, ktime_to_us(lrbp->compl_time_stamp));
		dev_err(hba->dev,
			"UPIU[%d] - Transfer Request Descriptor phys@0x%llx\n",
			tag, (u64)lrbp->utrd_dma_addr);

		ufshcd_hex_dump("UPIU TRD: ", lrbp->utr_descriptor_ptr,
				sizeof(struct utp_transfer_req_desc));
		dev_err(hba->dev, "UPIU[%d] - Request UPIU phys@0x%llx\n", tag,
			(u64)lrbp->ucd_req_dma_addr);
		ufshcd_hex_dump("UPIU REQ: ", lrbp->ucd_req_ptr,
				sizeof(struct utp_upiu_req));
		dev_err(hba->dev, "UPIU[%d] - Response UPIU phys@0x%llx\n", tag,
			(u64)lrbp->ucd_rsp_dma_addr);
		ufshcd_hex_dump("UPIU RSP: ", lrbp->ucd_rsp_ptr,
				sizeof(struct utp_upiu_rsp));

		prdt_length = le16_to_cpu(
			lrbp->utr_descriptor_ptr->prd_table_length);
		dev_err(hba->dev,
			"UPIU[%d] - PRDT - %d entries  phys@0x%llx\n",
			tag, prdt_length,
			(u64)lrbp->ucd_prdt_dma_addr);

		if (pr_prdt)
			ufshcd_hex_dump("UPIU PRDT: ", lrbp->ucd_prdt_ptr,
				sizeof(struct ufshcd_sg_entry) * prdt_length);
	}
}

static void ufshcd_print_tmrs(struct ufs_hba *hba, unsigned long bitmap)
{
	int tag;

	for_each_set_bit(tag, &bitmap, hba->nutmrs) {
		struct utp_task_req_desc *tmrdp = &hba->utmrdl_base_addr[tag];

		dev_err(hba->dev, "TM[%d] - Task Management Header\n", tag);
		ufshcd_hex_dump("", tmrdp, sizeof(*tmrdp));
	}
}

static void ufshcd_print_host_state(struct ufs_hba *hba)
{
	dev_err(hba->dev, "UFS Host state=%d\n", hba->ufshcd_state);
	dev_err(hba->dev, "lrb in use=0x%lx, outstanding reqs=0x%lx tasks=0x%lx\n",
		hba->lrb_in_use, hba->outstanding_reqs, hba->outstanding_tasks);
	dev_err(hba->dev, "saved_err=0x%x, saved_uic_err=0x%x\n",
		hba->saved_err, hba->saved_uic_err);
	dev_err(hba->dev, "Device power mode=%d, UIC link state=%d\n",
		hba->curr_dev_pwr_mode, hba->uic_link_state);
	dev_err(hba->dev, "PM in progress=%d, sys. suspended=%d\n",
		hba->pm_op_in_progress, hba->is_sys_suspended);
	dev_err(hba->dev, "Auto BKOPS=%d, Host self-block=%d\n",
		hba->auto_bkops_enabled, hba->host->host_self_blocked);
	dev_err(hba->dev, "Clk gate=%d\n", hba->clk_gating.state);
	dev_err(hba->dev, "error handling flags=0x%x, req. abort count=%d\n",
		hba->eh_flags, hba->req_abort_count);
	dev_err(hba->dev, "Host capabilities=0x%x, caps=0x%x\n",
		hba->capabilities, hba->caps);
	dev_err(hba->dev, "quirks=0x%x, dev. quirks=0x%x\n", hba->quirks,
		hba->dev_quirks);
}

/**
 * ufshcd_print_pwr_info - print power params as saved in hba
 * power info
 * @hba: per-adapter instance
 */
static void ufshcd_print_pwr_info(struct ufs_hba *hba)
{
	static const char * const names[] = {
		"INVALID MODE",
		"FAST MODE",
		"SLOW_MODE",
		"INVALID MODE",
		"FASTAUTO_MODE",
		"SLOWAUTO_MODE",
		"INVALID MODE",
	};

	dev_err(hba->dev, "%s:[RX, TX]: gear=[%d, %d], lane[%d, %d], pwr[%s, %s], rate = %d\n",
		 __func__,
		 hba->pwr_info.gear_rx, hba->pwr_info.gear_tx,
		 hba->pwr_info.lane_rx, hba->pwr_info.lane_tx,
		 names[hba->pwr_info.pwr_rx],
		 names[hba->pwr_info.pwr_tx],
		 hba->pwr_info.hs_rate);
}

/*
 * 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
 * @can_sleep - perform sleep or just spin
 *
 * Returns -ETIMEDOUT on error, zero on success
 */
int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
				u32 val, unsigned long interval_us,
				unsigned long timeout_ms, bool can_sleep)
{
	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) {
		if (can_sleep)
			usleep_range(interval_us, interval_us + 50);
		else
			udelay(interval_us);
		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)
{
	u32 intr_mask = 0;

	switch (hba->ufs_version) {
	case UFSHCI_VERSION_10:
		intr_mask = INTERRUPT_MASK_ALL_VER_10;
		break;
	case UFSHCI_VERSION_11:
	case UFSHCI_VERSION_20:
		intr_mask = INTERRUPT_MASK_ALL_VER_11;
		break;
	case UFSHCI_VERSION_21:
	default:
		intr_mask = INTERRUPT_MASK_ALL_VER_21;
		break;
	}

	return intr_mask;
}

/**
 * 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)
{
	if (hba->quirks & UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION)
		return ufshcd_vops_get_ufs_hci_version(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 true if device present, false if no device detected
 */
static inline bool ufshcd_is_device_present(struct ufs_hba *hba)
{
	return (ufshcd_readl(hba, REG_CONTROLLER_STATUS) &
						DEVICE_PRESENT) ? true : false;
}

/**
 * ufshcd_get_tr_ocs - Get the UTRD Overall Command Status
 * @lrbp: 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_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)
{
	if (hba->quirks & UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR)
		ufshcd_writel(hba, (1 << pos), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
	else
		ufshcd_writel(hba, ~(1 << pos),
				REG_UTP_TRANSFER_REQ_LIST_CLEAR);
}

/**
 * ufshcd_utmrl_clear - Clear a bit in UTRMLCLR register
 * @hba: per adapter instance
 * @pos: position of the bit to be cleared
 */
static inline void ufshcd_utmrl_clear(struct ufs_hba *hba, u32 pos)
{
	if (hba->quirks & UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR)
		ufshcd_writel(hba, (1 << pos), REG_UTP_TASK_REQ_LIST_CLEAR);
	else
		ufshcd_writel(hba, ~(1 << pos), REG_UTP_TASK_REQ_LIST_CLEAR);
}

/**
 * ufshcd_outstanding_req_clear - Clear a bit in outstanding request field
 * @hba: per adapter instance
 * @tag: position of the bit to be cleared
 */
static inline void ufshcd_outstanding_req_clear(struct ufs_hba *hba, int tag)
{
	__clear_bit(tag, &hba->outstanding_reqs);
}

/**
 * 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)
{
	return !((reg & UFSHCD_STATUS_READY) == UFSHCD_STATUS_READY);
}

/**
 * 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_disable_intr_aggr - Disables interrupt aggregation.
 * @hba: per adapter instance
 */
static inline void ufshcd_disable_intr_aggr(struct ufs_hba *hba)
{
	ufshcd_writel(hba, 0, 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 false if controller is active, true otherwise
 */
static inline bool ufshcd_is_hba_active(struct ufs_hba *hba)
{
	return (ufshcd_readl(hba, REG_CONTROLLER_ENABLE) & CONTROLLER_ENABLE)
		? false : true;
}

u32 ufshcd_get_local_unipro_ver(struct ufs_hba *hba)
{
	/* HCI version 1.0 and 1.1 supports UniPro 1.41 */
	if ((hba->ufs_version == UFSHCI_VERSION_10) ||
	    (hba->ufs_version == UFSHCI_VERSION_11))
		return UFS_UNIPRO_VER_1_41;
	else
		return UFS_UNIPRO_VER_1_6;
}
EXPORT_SYMBOL(ufshcd_get_local_unipro_ver);

static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
{
	/*
	 * If both host and device support UniPro ver1.6 or later, PA layer
	 * parameters tuning happens during link startup itself.
	 *
	 * We can manually tune PA layer parameters if either host or device
	 * doesn't support UniPro ver 1.6 or later. But to keep manual tuning
	 * logic simple, we will only do manual tuning if local unipro version
	 * doesn't support ver1.6 or later.
	 */
	if (ufshcd_get_local_unipro_ver(hba) < UFS_UNIPRO_VER_1_6)
		return true;
	else
		return false;
}

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;
	ktime_t start = ktime_get();
	bool clk_state_changed = false;

	if (list_empty(head))
		goto out;

	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, PRE_CHANGE);
	if (ret)
		return ret;

	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;

				clk_state_changed = true;
				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;
				}
				trace_ufshcd_clk_scaling(dev_name(hba->dev),
						"scaled up", clki->name,
						clki->curr_freq,
						clki->max_freq);

				clki->curr_freq = clki->max_freq;

			} else if (!scale_up && clki->min_freq) {
				if (clki->curr_freq == clki->min_freq)
					continue;

				clk_state_changed = true;
				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;
				}
				trace_ufshcd_clk_scaling(dev_name(hba->dev),
						"scaled down", clki->name,
						clki->curr_freq,
						clki->min_freq);
				clki->curr_freq = clki->min_freq;
			}
		}
		dev_dbg(hba->dev, "%s: clk: %s, rate: %lu\n", __func__,
				clki->name, clk_get_rate(clki->clk));
	}

	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);

out:
	if (clk_state_changed)
		trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
			(scale_up ? "up" : "down"),
			ktime_to_us(ktime_sub(ktime_get(), start)), ret);
	return ret;
}

/**
 * ufshcd_is_devfreq_scaling_required - check if scaling is required or not
 * @hba: per adapter instance
 * @scale_up: True if scaling up and false if scaling down
 *
 * Returns true if scaling is required, false otherwise.
 */
static bool ufshcd_is_devfreq_scaling_required(struct ufs_hba *hba,
					       bool scale_up)
{
	struct ufs_clk_info *clki;
	struct list_head *head = &hba->clk_list_head;

	if (list_empty(head))
		return false;

	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;
				return true;
			} else if (!scale_up && clki->min_freq) {
				if (clki->curr_freq == clki->min_freq)
					continue;
				return true;
			}
		}
	}

	return false;
}

static int ufshcd_wait_for_doorbell_clr(struct ufs_hba *hba,
					u64 wait_timeout_us)
{
	unsigned long flags;
	int ret = 0;
	u32 tm_doorbell;
	u32 tr_doorbell;
	bool timeout = false, do_last_check = false;
	ktime_t start;

	ufshcd_hold(hba, false);
	spin_lock_irqsave(hba->host->host_lock, flags);
	/*
	 * Wait for all the outstanding tasks/transfer requests.
	 * Verify by checking the doorbell registers are clear.
	 */
	start = ktime_get();
	do {
		if (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL) {
			ret = -EBUSY;
			goto out;
		}

		tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
		tr_doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
		if (!tm_doorbell && !tr_doorbell) {
			timeout = false;
			break;
		} else if (do_last_check) {
			break;
		}

		spin_unlock_irqrestore(hba->host->host_lock, flags);
		schedule();
		if (ktime_to_us(ktime_sub(ktime_get(), start)) >
		    wait_timeout_us) {
			timeout = true;
			/*
			 * We might have scheduled out for long time so make
			 * sure to check if doorbells are cleared by this time
			 * or not.
			 */
			do_last_check = true;
		}
		spin_lock_irqsave(hba->host->host_lock, flags);
	} while (tm_doorbell || tr_doorbell);

	if (timeout) {
		dev_err(hba->dev,
			"%s: timedout waiting for doorbell to clear (tm=0x%x, tr=0x%x)\n",
			__func__, tm_doorbell, tr_doorbell);
		ret = -EBUSY;
	}
out:
	spin_unlock_irqrestore(hba->host->host_lock, flags);
	ufshcd_release(hba);
	return ret;
}

/**
 * ufshcd_scale_gear - scale up/down UFS gear
 * @hba: per adapter instance
 * @scale_up: True for scaling up gear and false for scaling down
 *
 * Returns 0 for success,
 * Returns -EBUSY if scaling can't happen at this time
 * Returns non-zero for any other errors
 */
static int ufshcd_scale_gear(struct ufs_hba *hba, bool scale_up)
{
	#define UFS_MIN_GEAR_TO_SCALE_DOWN	UFS_HS_G1
	int ret = 0;
	struct ufs_pa_layer_attr new_pwr_info;

	if (scale_up) {
		memcpy(&new_pwr_info, &hba->clk_scaling.saved_pwr_info.info,
		       sizeof(struct ufs_pa_layer_attr));
	} else {
		memcpy(&new_pwr_info, &hba->pwr_info,
		       sizeof(struct ufs_pa_layer_attr));

		if (hba->pwr_info.gear_tx > UFS_MIN_GEAR_TO_SCALE_DOWN
		    || hba->pwr_info.gear_rx > UFS_MIN_GEAR_TO_SCALE_DOWN) {
			/* save the current power mode */
			memcpy(&hba->clk_scaling.saved_pwr_info.info,
				&hba->pwr_info,
				sizeof(struct ufs_pa_layer_attr));

			/* scale down gear */
			new_pwr_info.gear_tx = UFS_MIN_GEAR_TO_SCALE_DOWN;
			new_pwr_info.gear_rx = UFS_MIN_GEAR_TO_SCALE_DOWN;
		}
	}

	/* check if the power mode needs to be changed or not? */
	ret = ufshcd_change_power_mode(hba, &new_pwr_info);

	if (ret)
		dev_err(hba->dev, "%s: failed err %d, old gear: (tx %d rx %d), new gear: (tx %d rx %d)",
			__func__, ret,
			hba->pwr_info.gear_tx, hba->pwr_info.gear_rx,
			new_pwr_info.gear_tx, new_pwr_info.gear_rx);

	return ret;
}

static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba)
{
	#define DOORBELL_CLR_TOUT_US		(1000 * 1000) /* 1 sec */
	int ret = 0;
	/*
	 * make sure that there are no outstanding requests when
	 * clock scaling is in progress
	 */
	ufshcd_scsi_block_requests(hba);
	down_write(&hba->clk_scaling_lock);
	if (ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US)) {
		ret = -EBUSY;
		up_write(&hba->clk_scaling_lock);
		ufshcd_scsi_unblock_requests(hba);
	}

	return ret;
}

static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba)
{
	up_write(&hba->clk_scaling_lock);
	ufshcd_scsi_unblock_requests(hba);
}

/**
 * ufshcd_devfreq_scale - scale up/down UFS clocks and gear
 * @hba: per adapter instance
 * @scale_up: True for scaling up and false for scalin down
 *
 * Returns 0 for success,
 * Returns -EBUSY if scaling can't happen at this time
 * Returns non-zero for any other errors
 */
static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
{
	int ret = 0;

	/* let's not get into low power until clock scaling is completed */
	ufshcd_hold(hba, false);

	ret = ufshcd_clock_scaling_prepare(hba);
	if (ret)
		return ret;

	/* scale down the gear before scaling down clocks */
	if (!scale_up) {
		ret = ufshcd_scale_gear(hba, false);
		if (ret)
			goto out;
	}

	ret = ufshcd_scale_clks(hba, scale_up);
	if (ret) {
		if (!scale_up)
			ufshcd_scale_gear(hba, true);
		goto out;
	}

	/* scale up the gear after scaling up clocks */
	if (scale_up) {
		ret = ufshcd_scale_gear(hba, true);
		if (ret) {
			ufshcd_scale_clks(hba, false);
			goto out;
		}
	}

	ret = ufshcd_vops_clk_scale_notify(hba, scale_up, POST_CHANGE);

out:
	ufshcd_clock_scaling_unprepare(hba);
	ufshcd_release(hba);
	return ret;
}

static void ufshcd_clk_scaling_suspend_work(struct work_struct *work)
{
	struct ufs_hba *hba = container_of(work, struct ufs_hba,
					   clk_scaling.suspend_work);
	unsigned long irq_flags;

	spin_lock_irqsave(hba->host->host_lock, irq_flags);
	if (hba->clk_scaling.active_reqs || hba->clk_scaling.is_suspended) {
		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
		return;
	}
	hba->clk_scaling.is_suspended = true;
	spin_unlock_irqrestore(hba->host->host_lock, irq_flags);

	__ufshcd_suspend_clkscaling(hba);
}

static void ufshcd_clk_scaling_resume_work(struct work_struct *work)
{
	struct ufs_hba *hba = container_of(work, struct ufs_hba,
					   clk_scaling.resume_work);
	unsigned long irq_flags;

	spin_lock_irqsave(hba->host->host_lock, irq_flags);
	if (!hba->clk_scaling.is_suspended) {
		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
		return;
	}
	hba->clk_scaling.is_suspended = false;
	spin_unlock_irqrestore(hba->host->host_lock, irq_flags);

	devfreq_resume_device(hba->devfreq);
}

static int ufshcd_devfreq_target(struct device *dev,
				unsigned long *freq, u32 flags)
{
	int ret = 0;
	struct ufs_hba *hba = dev_get_drvdata(dev);
	ktime_t start;
	bool scale_up, sched_clk_scaling_suspend_work = false;
	struct list_head *clk_list = &hba->clk_list_head;
	struct ufs_clk_info *clki;
	unsigned long irq_flags;

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

	spin_lock_irqsave(hba->host->host_lock, irq_flags);
	if (ufshcd_eh_in_progress(hba)) {
		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
		return 0;
	}

	if (!hba->clk_scaling.active_reqs)
		sched_clk_scaling_suspend_work = true;

	if (list_empty(clk_list)) {
		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
		goto out;
	}

	clki = list_first_entry(&hba->clk_list_head, struct ufs_clk_info, list);
	scale_up = (*freq == clki->max_freq) ? true : false;
	if (!ufshcd_is_devfreq_scaling_required(hba, scale_up)) {
		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
		ret = 0;
		goto out; /* no state change required */
	}
	spin_unlock_irqrestore(hba->host->host_lock, irq_flags);

	start = ktime_get();
	ret = ufshcd_devfreq_scale(hba, scale_up);

	trace_ufshcd_profile_clk_scaling(dev_name(hba->dev),
		(scale_up ? "up" : "down"),
		ktime_to_us(ktime_sub(ktime_get(), start)), ret);

out:
	if (sched_clk_scaling_suspend_work)
		queue_work(hba->clk_scaling.workq,
			   &hba->clk_scaling.suspend_work);

	return ret;
}


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_supported(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 = 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,
};

static int ufshcd_devfreq_init(struct ufs_hba *hba)
{
	struct list_head *clk_list = &hba->clk_list_head;
	struct ufs_clk_info *clki;
	struct devfreq *devfreq;
	int ret;

	/* Skip devfreq if we don't have any clocks in the list */
	if (list_empty(clk_list))
		return 0;

	clki = list_first_entry(clk_list, struct ufs_clk_info, list);
	dev_pm_opp_add(hba->dev, clki->min_freq, 0);
	dev_pm_opp_add(hba->dev, clki->max_freq, 0);

	devfreq = devfreq_add_device(hba->dev,
			&ufs_devfreq_profile,
			DEVFREQ_GOV_SIMPLE_ONDEMAND,
			NULL);
	if (IS_ERR(devfreq)) {
		ret = PTR_ERR(devfreq);
		dev_err(hba->dev, "Unable to register with devfreq %d\n", ret);

		dev_pm_opp_remove(hba->dev, clki->min_freq);
		dev_pm_opp_remove(hba->dev, clki->max_freq);
		return ret;
	}

	hba->devfreq = devfreq;

	return 0;
}

static void ufshcd_devfreq_remove(struct ufs_hba *hba)
{
	struct list_head *clk_list = &hba->clk_list_head;
	struct ufs_clk_info *clki;

	if (!hba->devfreq)
		return;

	devfreq_remove_device(hba->devfreq);
	hba->devfreq = NULL;

	clki = list_first_entry(clk_list, struct ufs_clk_info, list);
	dev_pm_opp_remove(hba->dev, clki->min_freq);
	dev_pm_opp_remove(hba->dev, clki->max_freq);
}

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

	devfreq_suspend_device(hba->devfreq);
	spin_lock_irqsave(hba->host->host_lock, flags);
	hba->clk_scaling.window_start_t = 0;
	spin_unlock_irqrestore(hba->host->host_lock, flags);
}

static void ufshcd_suspend_clkscaling(struct ufs_hba *hba)
{
	unsigned long flags;
	bool suspend = false;

	if (!ufshcd_is_clkscaling_supported(hba))
		return;

	spin_lock_irqsave(hba->host->host_lock, flags);
	if (!hba->clk_scaling.is_suspended) {
		suspend = true;
		hba->clk_scaling.is_suspended = true;
	}
	spin_unlock_irqrestore(hba->host->host_lock, flags);

	if (suspend)
		__ufshcd_suspend_clkscaling(hba);
}

static void ufshcd_resume_clkscaling(struct ufs_hba *hba)
{
	unsigned long flags;
	bool resume = false;

	if (!ufshcd_is_clkscaling_supported(hba))
		return;

	spin_lock_irqsave(hba->host->host_lock, flags);
	if (hba->clk_scaling.is_suspended) {
		resume = true;
		hba->clk_scaling.is_suspended = false;
	}
	spin_unlock_irqrestore(hba->host->host_lock, flags);

	if (resume)
		devfreq_resume_device(hba->devfreq);
}

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

	return snprintf(buf, PAGE_SIZE, "%d\n", hba->clk_scaling.is_allowed);
}

static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct ufs_hba *hba = dev_get_drvdata(dev);
	u32 value;
	int err;

	if (kstrtou32(buf, 0, &value))
		return -EINVAL;

	value = !!value;
	if (value == hba->clk_scaling.is_allowed)
		goto out;

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

	cancel_work_sync(&hba->clk_scaling.suspend_work);
	cancel_work_sync(&hba->clk_scaling.resume_work);

	hba->clk_scaling.is_allowed = value;

	if (value) {
		ufshcd_resume_clkscaling(hba);
	} else {
		ufshcd_suspend_clkscaling(hba);
		err = ufshcd_devfreq_scale(hba, true);
		if (err)
			dev_err(hba->dev, "%s: failed to scale clocks up %d\n",
					__func__, err);
	}

	ufshcd_release(hba);
	pm_runtime_put_sync(hba->dev);
out:
	return count;
}

static void ufshcd_clkscaling_init_sysfs(struct ufs_hba *hba)
{
	hba->clk_scaling.enable_attr.show = ufshcd_clkscale_enable_show;
	hba->clk_scaling.enable_attr.store = ufshcd_clkscale_enable_store;
	sysfs_attr_init(&hba->clk_scaling.enable_attr.attr);
	hba->clk_scaling.enable_attr.attr.name = "clkscale_enable";
	hba->clk_scaling.enable_attr.attr.mode = 0644;
	if (device_create_file(hba->dev, &hba->clk_scaling.enable_attr))
		dev_err(hba->dev, "Failed to create sysfs for clkscale_enable\n");
}

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:
	ufshcd_scsi_unblock_requests(hba);
}

/**
 * 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++;

	if (ufshcd_eh_in_progress(hba)) {
		spin_unlock_irqrestore(hba->host->host_lock, flags);
		return 0;
	}

start:
	switch (hba->clk_gating.state) {
	case CLKS_ON:
		/*
		 * Wait for the ungate work to complete if in progress.
		 * Though the clocks may be in ON state, the link could
		 * still be in hibner8 state if hibern8 is allowed
		 * during clock gating.
		 * Make sure we exit hibern8 state also in addition to
		 * clocks being ON.
		 */
		if (ufshcd_can_hibern8_during_gating(hba) &&
		    ufshcd_is_link_hibern8(hba)) {
			spin_unlock_irqrestore(hba->host->host_lock, flags);
			flush_work(&hba->clk_gating.ungate_work);
			spin_lock_irqsave(hba->host->host_lock, flags);
			goto start;
		}
		break;
	case REQ_CLKS_OFF:
		if (cancel_delayed_work(&hba->clk_gating.gate_work)) {
			hba->clk_gating.state = CLKS_ON;
			trace_ufshcd_clk_gating(dev_name(hba->dev),
						hba->clk_gating.state);
			break;
		}
		/*
		 * If we are here, it means gating work is either done or
		 * currently running. Hence, fall through to cancel gating
		 * work and to enable clocks.
		 */
		/* fallthrough */
	case CLKS_OFF:
		ufshcd_scsi_block_requests(hba);
		hba->clk_gating.state = REQ_CLKS_ON;
		trace_ufshcd_clk_gating(dev_name(hba->dev),
					hba->clk_gating.state);
		queue_work(hba->clk_gating.clk_gating_workq,
			   &hba->clk_gating.ungate_work);
		/*
		 * fall through to check if we should wait for this
		 * work to be done or not.
		 */
		/* fallthrough */
	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;
}
EXPORT_SYMBOL_GPL(ufshcd_hold);

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);
	/*
	 * In case you are here to cancel this work the gating state
	 * would be marked as REQ_CLKS_ON. In this case save time by
	 * skipping the gating work and exit after changing the clock
	 * state to CLKS_ON.
	 */
	if (hba->clk_gating.is_suspended ||
		(hba->clk_gating.state == REQ_CLKS_ON)) {
		hba->clk_gating.state = CLKS_ON;
		trace_ufshcd_clk_gating(dev_name(hba->dev),
					hba->clk_gating.state);
		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;
			trace_ufshcd_clk_gating(dev_name(hba->dev),
						hba->clk_gating.state);
			goto out;
		}
		ufshcd_set_link_hibern8(hba);
	}

	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;
		trace_ufshcd_clk_gating(dev_name(hba->dev),
					hba->clk_gating.state);
	}
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
		|| ufshcd_eh_in_progress(hba))
		return;

	hba->clk_gating.state = REQ_CLKS_OFF;
	trace_ufshcd_clk_gating(dev_name(hba->dev), hba->clk_gating.state);
	queue_delayed_work(hba->clk_gating.clk_gating_workq,
			   &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);
}
EXPORT_SYMBOL_GPL(ufshcd_release);

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

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

static ssize_t ufshcd_clkgate_enable_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;
	u32 value;

	if (kstrtou32(buf, 0, &value))
		return -EINVAL;

	value = !!value;
	if (value == hba->clk_gating.is_enabled)
		goto out;

	if (value) {
		ufshcd_release(hba);
	} else {
		spin_lock_irqsave(hba->host->host_lock, flags);
		hba->clk_gating.active_reqs++;
		spin_unlock_irqrestore(hba->host->host_lock, flags);
	}

	hba->clk_gating.is_enabled = value;
out:
	return count;
}

static void ufshcd_init_clk_scaling(struct ufs_hba *hba)
{
	char wq_name[sizeof("ufs_clkscaling_00")];

	if (!ufshcd_is_clkscaling_supported(hba))
		return;

	INIT_WORK(&hba->clk_scaling.suspend_work,
		  ufshcd_clk_scaling_suspend_work);
	INIT_WORK(&hba->clk_scaling.resume_work,
		  ufshcd_clk_scaling_resume_work);

	snprintf(wq_name, sizeof(wq_name), "ufs_clkscaling_%d",
		 hba->host->host_no);
	hba->clk_scaling.workq = create_singlethread_workqueue(wq_name);

	ufshcd_clkscaling_init_sysfs(hba);
}

static void ufshcd_exit_clk_scaling(struct ufs_hba *hba)
{
	if (!ufshcd_is_clkscaling_supported(hba))
		return;

	destroy_workqueue(hba->clk_scaling.workq);
	ufshcd_devfreq_remove(hba);
}

static void ufshcd_init_clk_gating(struct ufs_hba *hba)
{
	char wq_name[sizeof("ufs_clk_gating_00")];

	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);

	snprintf(wq_name, ARRAY_SIZE(wq_name), "ufs_clk_gating_%d",
		 hba->host->host_no);
	hba->clk_gating.clk_gating_workq = alloc_ordered_workqueue(wq_name,
							   WQ_MEM_RECLAIM);

	hba->clk_gating.is_enabled = true;

	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 = 0644;
	if (device_create_file(hba->dev, &hba->clk_gating.delay_attr))
		dev_err(hba->dev, "Failed to create sysfs for clkgate_delay\n");

	hba->clk_gating.enable_attr.show = ufshcd_clkgate_enable_show;
	hba->clk_gating.enable_attr.store = ufshcd_clkgate_enable_store;
	sysfs_attr_init(&hba->clk_gating.enable_attr.attr);
	hba->clk_gating.enable_attr.attr.name = "clkgate_enable";
	hba->clk_gating.enable_attr.attr.mode = 0644;
	if (device_create_file(hba->dev, &hba->clk_gating.enable_attr))
		dev_err(hba->dev, "Failed to create sysfs for clkgate_enable\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);
	device_remove_file(hba->dev, &hba->clk_gating.enable_attr);
	cancel_work_sync(&hba->clk_gating.ungate_work);
	cancel_delayed_work_sync(&hba->clk_gating.gate_work);
	destroy_workqueue(hba->clk_gating.clk_gating_workq);
}

/* Must be called with host lock acquired */
static void ufshcd_clk_scaling_start_busy(struct ufs_hba *hba)
{
	bool queue_resume_work = false;

	if (!ufshcd_is_clkscaling_supported(hba))
		return;

	if (!hba->clk_scaling.active_reqs++)
		queue_resume_work = true;

	if (!hba->clk_scaling.is_allowed || hba->pm_op_in_progress)
		return;

	if (queue_resume_work)
		queue_work(hba->clk_scaling.workq,
			   &hba->clk_scaling.resume_work);

	if (!hba->clk_scaling.window_start_t) {
		hba->clk_scaling.window_start_t = jiffies;
		hba->clk_scaling.tot_busy_t = 0;
		hba->clk_scaling.is_busy_started = false;
	}

	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_supported(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 = 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)
{
	hba->lrb[task_tag].issue_time_stamp = ktime_get();
	hba->lrb[task_tag].compl_time_stamp = ktime_set(0, 0);
	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);
	/* Make sure that doorbell is committed immediately */
	wmb();
	ufshcd_add_command_trace(hba, task_tag, "send");
}

/**
 * ufshcd_copy_sense_data - Copy sense data in case of check condition
 * @lrbp: 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)) {
		int len_to_copy;

		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sr.sense_data_len);
		len_to_copy = min_t(int, UFS_SENSE_SIZE, len);

		memcpy(lrbp->sense_buffer, lrbp->ucd_rsp_ptr->sr.sense_data,
		       len_to_copy);
	}
}

/**
 * ufshcd_copy_query_response() - Copy the Query Response and the data
 * descriptor
 * @hba: per adapter instance
 * @lrbp: 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 (hba->dev_cmd.query.descriptor &&
	    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_cmd: 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
 * @completion: initialize the completion only if this is set to true
 *
 * 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,
		      bool completion)
{
	if (!ufshcd_ready_for_uic_cmd(hba)) {
		dev_err(hba->dev,
			"Controller not ready to accept UIC commands\n");
		return -EIO;
	}

	if (completion)
		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.
 */
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);
	ufshcd_add_delay_before_dme_cmd(hba);

	spin_lock_irqsave(hba->host->host_lock, flags);
	ret = __ufshcd_send_uic_cmd(hba, uic_cmd, true);
	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
 * @hba: per adapter instance
 * @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 ufs_hba *hba, 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) {
		if (hba->quirks & UFSHCD_QUIRK_PRDT_BYTE_GRAN)
			lrbp->utr_descriptor_ptr->prd_table_length =
				cpu_to_le16((u16)(sg_segments *
					sizeof(struct ufshcd_sg_entry)));
		else
			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));
			prd_table[i].reserved = 0;
		}
	} 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);
	/* dword_1 is reserved, hence it is set to 0 */
	req_desc->header.dword_1 = 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);
	/* dword_3 is reserved, hence it is set to 0 */
	req_desc->header.dword_3 = 0;

	req_desc->prd_table_length = 0;
}

/**
 * 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;
	unsigned short cdb_len;

	/* 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);

	cdb_len = min_t(unsigned short, lrbp->cmd->cmd_len, UFS_CDB_SIZE);
	memset(ucd_req_ptr->sc.cdb, 0, UFS_CDB_SIZE);
	memcpy(ucd_req_ptr->sc.cdb, lrbp->cmd->cmnd, cdb_len);

	memset(lrbp->ucd_rsp_ptr, 0, sizeof(struct utp_upiu_rsp));
}

/**
 * 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);

	/* 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 only need for WRITE_DESC */
	if (query->request.upiu_req.opcode == UPIU_QUERY_OPCODE_WRITE_DESC)
		ucd_req_ptr->header.dword_2 =
			UPIU_HEADER_DWORD(0, 0, (len >> 8), (u8)len);
	else
		ucd_req_ptr->header.dword_2 = 0;

	/* 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(ucd_req_ptr + 1, query->descriptor, len);

	memset(lrbp->ucd_rsp_ptr, 0, sizeof(struct utp_upiu_rsp));
}

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);
	/* clear rest of the fields of basic header */
	ucd_req_ptr->header.dword_1 = 0;
	ucd_req_ptr->header.dword_2 = 0;

	memset(lrbp->ucd_rsp_ptr, 0, sizeof(struct utp_upiu_rsp));
}

/**
 * ufshcd_comp_devman_upiu - UFS Protocol Information Unit(UPIU)
 *			     for Device Management Purposes
 * @hba: per adapter instance
 * @lrbp: pointer to local reference block
 */
static int ufshcd_comp_devman_upiu(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
{
	u32 upiu_flags;
	int ret = 0;

	if ((hba->ufs_version == UFSHCI_VERSION_10) ||
	    (hba->ufs_version == UFSHCI_VERSION_11))
		lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
	else
		lrbp->command_type = UTP_CMD_TYPE_UFS_STORAGE;

	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;

	return ret;
}

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

	if ((hba->ufs_version == UFSHCI_VERSION_10) ||
	    (hba->ufs_version == UFSHCI_VERSION_11))
		lrbp->command_type = UTP_CMD_TYPE_SCSI;
	else
		lrbp->command_type = UTP_CMD_TYPE_UFS_STORAGE;

	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;
	}

	return ret;
}

/**
 * ufshcd_upiu_wlun_to_scsi_wlun - maps UPIU W-LUN id to SCSI W-LUN ID
 * @upiu_wlun_id: 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
 * @host: SCSI host pointer
 * @cmd: command from SCSI Midlayer
 *
 * 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;
	if (!ufshcd_valid_tag(hba, tag)) {
		dev_err(hba->dev,
			"%s: invalid command tag %d: cmd=0x%p, cmd->request=0x%p",
			__func__, tag, cmd, cmd->request);
		BUG();
	}

	if (!down_read_trylock(&hba->clk_scaling_lock))
		return SCSI_MLQUEUE_HOST_BUSY;

	spin_lock_irqsave(hba->host->host_lock, flags);
	switch (hba->ufshcd_state) {
	case UFSHCD_STATE_OPERATIONAL:
		break;
	case UFSHCD_STATE_EH_SCHEDULED:
	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;
	}

	/* if error handling is in progress, don't issue commands */
	if (ufshcd_eh_in_progress(hba)) {
		set_host_byte(cmd, DID_ERROR);
		cmd->scsi_done(cmd);
		goto out_unlock;
	}
	spin_unlock_irqrestore(hba->host->host_lock, flags);

	hba->req_abort_count = 0;

	/* 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 = UFS_SENSE_SIZE;
	lrbp->sense_buffer = cmd->sense_buffer;
	lrbp->task_tag = tag;
	lrbp->lun = ufshcd_scsi_to_upiu_lun(cmd->device->lun);
	lrbp->intr_cmd = !ufshcd_is_intr_aggr_allowed(hba) ? true : false;
	lrbp->req_abort_skip = false;

	ufshcd_comp_scsi_upiu(hba, lrbp);

	err = ufshcd_map_sg(hba, lrbp);
	if (err) {
		lrbp->cmd = NULL;
		clear_bit_unlock(tag, &hba->lrb_in_use);
		goto out;
	}
	/* Make sure descriptors are ready before ringing the doorbell */
	wmb();

	/* issue command to the controller */
	spin_lock_irqsave(hba->host->host_lock, flags);
	ufshcd_vops_setup_xfer_req(hba, tag, (lrbp->cmd ? true : false));
	ufshcd_send_command(hba, tag);
out_unlock:
	spin_unlock_irqrestore(hba->host->host_lock, flags);
out:
	up_read(&hba->clk_scaling_lock);
	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->intr_cmd = true; /* No interrupt aggregation */
	hba->dev_cmd.type = cmd_type;

	return ufshcd_comp_devman_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, true);

	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;

	hba->ufs_stats.last_hibern8_exit_tstamp = ktime_set(0, 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));

	/* Make sure descriptors are ready before ringing the doorbell */
	wmb();
	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;
		dev_dbg(hba->dev, "%s: dev_cmd request timedout, tag %d\n",
			__func__, lrbp->task_tag);
		if (!ufshcd_clear_cmd(hba, lrbp->task_tag))
			/* successfully cleared the command, retry if needed */
			err = -EAGAIN;
		/*
		 * in case of an error, after clearing the doorbell,
		 * we also need to clear the outstanding_request
		 * field in hba
		 */
		ufshcd_outstanding_req_clear(hba, lrbp->task_tag);
	}

	return err;
}

/**
 * ufshcd_get_dev_cmd_tag - Get device management command tag
 * @hba: per-adapter instance
 * @tag_out: 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;

	down_read(&hba->clk_scaling_lock);

	/*
	 * 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;

	ufshcd_add_query_upiu_trace(hba, tag, "query_send");
	/* Make sure descriptors are ready before ringing the doorbell */
	wmb();
	spin_lock_irqsave(hba->host->host_lock, flags);
	ufshcd_vops_setup_xfer_req(hba, tag, (lrbp->cmd ? true : false));
	ufshcd_send_command(hba, tag);
	spin_unlock_irqrestore(hba->host->host_lock, flags);

	err = ufshcd_wait_for_dev_cmd(hba, lrbp, timeout);

	ufshcd_add_query_upiu_trace(hba, tag,
			err ? "query_complete_err" : "query_complete");

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

static int ufshcd_query_flag_retry(struct ufs_hba *hba,
	enum query_opcode opcode, enum flag_idn idn, bool *flag_res)
{
	int ret;
	int retries;

	for (retries = 0; retries < QUERY_REQ_RETRIES; retries++) {
		ret = ufshcd_query_flag(hba, opcode, idn, flag_res);
		if (ret)
			dev_dbg(hba->dev,
				"%s: failed with error %d, retries %d\n",
				__func__, ret, retries);
		else
			break;
	}

	if (ret)
		dev_err(hba->dev,
			"%s: query attribute, opcode %d, idn %d, failed with error %d after %d retires\n",
			__func__, opcode, idn, ret, retries);
	return ret;
}

/**
 * ufshcd_query_flag() - API function for sending flag query requests
 * @hba: per-adapter instance
 * @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
 */
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;
	int timeout = QUERY_REQ_TIMEOUT;

	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, 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
*/
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, index %d, err = %d\n",
				__func__, opcode, idn, index, 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_attr_retry() - API function for sending query
 * attribute with retries
 * @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_retry(struct ufs_hba *hba,
	enum query_opcode opcode, enum attr_idn idn, u8 index, u8 selector,
	u32 *attr_val)
{
	int ret = 0;
	u32 retries;

	 for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
		ret = ufshcd_query_attr(hba, opcode, idn, index,
						selector, attr_val);
		if (ret)
			dev_dbg(hba->dev, "%s: failed with error %d, retries %d\n",
				__func__, ret, retries);
		else
			break;
	}

	if (ret)
		dev_err(hba->dev,
			"%s: query attribute, idn %d, failed with error %d after %d retires\n",
			__func__, idn, ret, QUERY_REQ_RETRIES);
	return ret;
}

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, index %d, err = %d\n",
				__func__, opcode, idn, index, 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_query_descriptor_retry - 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.
 */
int ufshcd_query_descriptor_retry(struct ufs_hba *hba,
				  enum query_opcode opcode,
				  enum desc_idn idn, u8 index,
				  u8 selector,
				  u8 *desc_buf, int *buf_len)
{
	int err;
	int retries;

	for (retries = QUERY_REQ_RETRIES; retries > 0; retries--) {
		err = __ufshcd_query_descriptor(hba, opcode, idn, index,
						selector, desc_buf, buf_len);
		if (!err || err == -EINVAL)
			break;
	}

	return err;
}

/**
 * ufshcd_read_desc_length - read the specified descriptor length from header
 * @hba: Pointer to adapter instance
 * @desc_id: descriptor idn value
 * @desc_index: descriptor index
 * @desc_length: pointer to variable to read the length of descriptor
 *
 * Return 0 in case of success, non-zero otherwise
 */
static int ufshcd_read_desc_length(struct ufs_hba *hba,
	enum desc_idn desc_id,
	int desc_index,
	int *desc_length)
{
	int ret;
	u8 header[QUERY_DESC_HDR_SIZE];
	int header_len = QUERY_DESC_HDR_SIZE;

	if (desc_id >= QUERY_DESC_IDN_MAX)
		return -EINVAL;

	ret = ufshcd_query_descriptor_retry(hba, UPIU_QUERY_OPCODE_READ_DESC,
					desc_id, desc_index, 0, header,
					&header_len);

	if (ret) {
		dev_err(hba->dev, "%s: Failed to get descriptor header id %d",
			__func__, desc_id);
		return ret;
	} else if (desc_id != header[QUERY_DESC_DESC_TYPE_OFFSET]) {
		dev_warn(hba->dev, "%s: descriptor header id %d and desc_id %d mismatch",
			__func__, header[QUERY_DESC_DESC_TYPE_OFFSET],
			desc_id);
		ret = -EINVAL;
	}

	*desc_length = header[QUERY_DESC_LENGTH_OFFSET];
	return ret;

}

/**
 * ufshcd_map_desc_id_to_length - map descriptor IDN to its length
 * @hba: Pointer to adapter instance
 * @desc_id: descriptor idn value
 * @desc_len: mapped desc length (out)
 *
 * Return 0 in case of success, non-zero otherwise
 */
int ufshcd_map_desc_id_to_length(struct ufs_hba *hba,
	enum desc_idn desc_id, int *desc_len)
{
	switch (desc_id) {
	case QUERY_DESC_IDN_DEVICE:
		*desc_len = hba->desc_size.dev_desc;
		break;
	case QUERY_DESC_IDN_POWER:
		*desc_len = hba->desc_size.pwr_desc;
		break;
	case QUERY_DESC_IDN_GEOMETRY:
		*desc_len = hba->desc_size.geom_desc;
		break;
	case QUERY_DESC_IDN_CONFIGURATION:
		*desc_len = hba->desc_size.conf_desc;
		break;
	case QUERY_DESC_IDN_UNIT:
		*desc_len = hba->desc_size.unit_desc;
		break;
	case QUERY_DESC_IDN_INTERCONNECT:
		*desc_len = hba->desc_size.interc_desc;
		break;
	case QUERY_DESC_IDN_STRING:
		*desc_len = QUERY_DESC_MAX_SIZE;
		break;
	case QUERY_DESC_IDN_HEALTH:
		*desc_len = hba->desc_size.hlth_desc;
		break;
	case QUERY_DESC_IDN_RFU_0:
	case QUERY_DESC_IDN_RFU_1:
		*desc_len = 0;
		break;
	default:
		*desc_len = 0;
		return -EINVAL;
	}
	return 0;
}
EXPORT_SYMBOL(ufshcd_map_desc_id_to_length);

/**
 * 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
 */
int ufshcd_read_desc_param(struct ufs_hba *hba,
			   enum desc_idn desc_id,
			   int desc_index,
			   u8 param_offset,
			   u8 *param_read_buf,
			   u8 param_size)