M7350/kernel/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
 *
 * 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.
 */

#include "ufshcd.h"

enum {
	UFSHCD_MAX_CHANNEL	= 0,
	UFSHCD_MAX_ID		= 1,
	UFSHCD_MAX_LUNS		= 8,
	UFSHCD_CMD_PER_LUN	= 32,
	UFSHCD_CAN_QUEUE	= 32,
};

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

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

/* Interrupt aggregation options */
enum {
	INT_AGGR_RESET,
	INT_AGGR_CONFIG,
};

/**
 * 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 readl(hba->mmio_base + REG_UFS_VERSION);
}

/**
 * ufshcd_is_device_present - Check if any device connected to
 *			      the host controller
 * @reg_hcs - host controller status register value
 *
 * Returns 1 if device present, 0 if no device detected
 */
static inline int ufshcd_is_device_present(u32 reg_hcs)
{
	return (DEVICE_PRESENT & reg_hcs) ? 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 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 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
 *
 * Returns maximum number of task management request slots in case of
 * task management queue full or returns the free slot number
 */
static inline int ufshcd_get_tm_free_slot(struct ufs_hba *hba)
{
	return find_first_zero_bit(&hba->outstanding_tasks, hba->nutmrs);
}

/**
 * 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)
{
	writel(~(1 << pos),
		(hba->mmio_base + 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 readl(hba->mmio_base + REG_UIC_COMMAND_ARG_2) &
	       MASK_UIC_COMMAND_RESULT;
}

/**
 * ufshcd_free_hba_memory - Free allocated memory for LRB, request
 *			    and task lists
 * @hba: Pointer to adapter instance
 */
static inline void ufshcd_free_hba_memory(struct ufs_hba *hba)
{
	size_t utmrdl_size, utrdl_size, ucdl_size;

	kfree(hba->lrb);

	if (hba->utmrdl_base_addr) {
		utmrdl_size = sizeof(struct utp_task_req_desc) * hba->nutmrs;
		dma_free_coherent(hba->dev, utmrdl_size,
				  hba->utmrdl_base_addr, hba->utmrdl_dma_addr);
	}

	if (hba->utrdl_base_addr) {
		utrdl_size =
		(sizeof(struct utp_transfer_req_desc) * hba->nutrs);
		dma_free_coherent(hba->dev, utrdl_size,
				  hba->utrdl_base_addr, hba->utrdl_dma_addr);
	}

	if (hba->ucdl_base_addr) {
		ucdl_size =
		(sizeof(struct utp_transfer_cmd_desc) * hba->nutrs);
		dma_free_coherent(hba->dev, ucdl_size,
				  hba->ucdl_base_addr, hba->ucdl_dma_addr);
	}
}

/**
 * ufshcd_get_req_rsp - returns the TR response
 * @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_config_int_aggr - Configure interrupt aggregation values.
 *		Currently there is no use case where we want to configure
 *		interrupt aggregation dynamically. So to configure interrupt
 *		aggregation, #define INT_AGGR_COUNTER_THRESHOLD_VALUE and
 *		INT_AGGR_TIMEOUT_VALUE are used.
 * @hba: per adapter instance
 * @option: Interrupt aggregation option
 */
static inline void
ufshcd_config_int_aggr(struct ufs_hba *hba, int option)
{
	switch (option) {
	case INT_AGGR_RESET:
		writel((INT_AGGR_ENABLE |
			INT_AGGR_COUNTER_AND_TIMER_RESET),
			(hba->mmio_base +
			 REG_UTP_TRANSFER_REQ_INT_AGG_CONTROL));
		break;
	case INT_AGGR_CONFIG:
		writel((INT_AGGR_ENABLE |
			INT_AGGR_PARAM_WRITE |
			INT_AGGR_COUNTER_THRESHOLD_VALUE |
			INT_AGGR_TIMEOUT_VALUE),
			(hba->mmio_base +
			 REG_UTP_TRANSFER_REQ_INT_AGG_CONTROL));
		break;
	}
}

/**
 * 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)
{
	writel(UTP_TASK_REQ_LIST_RUN_STOP_BIT,
	       (hba->mmio_base +
		REG_UTP_TASK_REQ_LIST_RUN_STOP));
	writel(UTP_TRANSFER_REQ_LIST_RUN_STOP_BIT,
	       (hba->mmio_base +
		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)
{
	writel(CONTROLLER_ENABLE , (hba->mmio_base + 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 (readl(hba->mmio_base + REG_CONTROLLER_ENABLE) & 0x1) ? 0 : 1;
}

/**
 * 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)
{
	__set_bit(task_tag, &hba->outstanding_reqs);
	writel((1 << task_tag),
	       (hba->mmio_base + 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) {
		len = be16_to_cpu(lrbp->ucd_rsp_ptr->sc.sense_data_len);
		memcpy(lrbp->sense_buffer,
			lrbp->ucd_rsp_ptr->sc.sense_data,
			min_t(int, len, SCSI_SENSE_BUFFERSIZE));
	}
}

/**
 * ufshcd_query_to_cpu() - formats the received buffer in to the native cpu
 * endian
 * @response: upiu query response to convert
 */
static inline void ufshcd_query_to_cpu(struct utp_upiu_query *response)
{
	response->length = be16_to_cpu(response->length);
	response->value = be32_to_cpu(response->value);
}

/**
 * ufshcd_query_to_be() - formats the buffer before sending in to big endian
 * @response: upiu query request to convert
 */
static inline void ufshcd_query_to_be(struct utp_upiu_query *request)
{
	request->length = cpu_to_be16(request->length);
	request->value = cpu_to_be32(request->value);
}

/**
 * ufshcd_copy_query_response() - Copy Query Response and descriptor
 * @lrb - pointer to local reference block
 * @query_res - pointer to the query result
 */
static
void ufshcd_copy_query_response(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
{
	struct ufs_query_res *query_res = hba->query.response;

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

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

	/* Get the descriptor */
	if (hba->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 len;

		/* data segment length */
		len = be32_to_cpu(lrbp->ucd_rsp_ptr->header.dword_2) &
						MASK_QUERY_DATA_SEG_LEN;

		memcpy(hba->query.descriptor, descp,
			min_t(u16, len, UPIU_HEADER_DATA_SEGMENT_MAX_SIZE));
	}
}

/**
 * ufshcd_hba_capabilities - Read controller capabilities
 * @hba: per adapter instance
 */
static inline void ufshcd_hba_capabilities(struct ufs_hba *hba)
{
	hba->capabilities =
		readl(hba->mmio_base + 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_send_uic_command - Send UIC commands to unipro layers
 * @hba: per adapter instance
 * @uic_command: UIC command
 */
static inline void
ufshcd_send_uic_command(struct ufs_hba *hba, struct uic_command *uic_cmnd)
{
	/* Write Args */
	writel(uic_cmnd->argument1,
	      (hba->mmio_base + REG_UIC_COMMAND_ARG_1));
	writel(uic_cmnd->argument2,
	      (hba->mmio_base + REG_UIC_COMMAND_ARG_2));
	writel(uic_cmnd->argument3,
	      (hba->mmio_base + REG_UIC_COMMAND_ARG_3));

	/* Write UIC Cmd */
	writel((uic_cmnd->command & COMMAND_OPCODE_MASK),
	       (hba->mmio_base + REG_UIC_COMMAND));
}

/**
 * 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_int_config - enable/disable interrupts
 * @hba: per adapter instance
 * @option: interrupt option
 */
static void ufshcd_int_config(struct ufs_hba *hba, u32 option)
{
	switch (option) {
	case UFSHCD_INT_ENABLE:
		writel(hba->int_enable_mask,
		      (hba->mmio_base + REG_INTERRUPT_ENABLE));
		break;
	case UFSHCD_INT_DISABLE:
		if (hba->ufs_version == UFSHCI_VERSION_10)
			writel(INTERRUPT_DISABLE_MASK_10,
			      (hba->mmio_base + REG_INTERRUPT_ENABLE));
		else
			writel(INTERRUPT_DISABLE_MASK_11,
			       (hba->mmio_base + REG_INTERRUPT_ENABLE));
		break;
	}
}

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

	/* 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);
}

static inline bool ufshcd_is_query_req(struct ufshcd_lrb *lrbp)
{
	return lrbp->cmd ? lrbp->cmd->cmnd[0] == UFS_QUERY_RESERVED_SCSI_CMD :
		false;
}

/**
 * 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;
	u16 len = hba->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, hba->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(&lrbp->ucd_req_ptr->qr, &hba->query.request->upiu_req,
			QUERY_OSF_SIZE);
	ufshcd_query_to_be(&lrbp->ucd_req_ptr->qr);

	/* Copy the Descriptor */
	if (hba->query.descriptor != NULL && len > 0 &&
		(hba->query.request->upiu_req.opcode ==
					UPIU_QUERY_OPCODE_WRITE_DESC)) {
		memcpy(descp, hba->query.descriptor,
			min_t(u16, len, UPIU_HEADER_DATA_SEGMENT_MAX_SIZE));
	}

}

/**
 * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
 * @hba - UFS hba
 * @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:
	case UTP_CMD_TYPE_DEV_MANAGE:
		ufshcd_prepare_req_desc(lrbp, &upiu_flags);
		if (lrbp->command_type == UTP_CMD_TYPE_SCSI)
			ufshcd_prepare_utp_scsi_cmd_upiu(lrbp, upiu_flags);
		else
			ufshcd_prepare_utp_query_req_upiu(hba, lrbp,
								upiu_flags);
		break;
	case UTP_CMD_TYPE_UFS:
		/* For UFS native command implementation */
		dev_err(hba->dev, "%s: UFS native command are not supported\n",
			__func__);
		ret = -ENOTSUPP;
		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_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;

	if (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL) {
		err = SCSI_MLQUEUE_HOST_BUSY;
		goto out;
	}

	lrbp = &hba->lrb[tag];

	lrbp->cmd = cmd;
	lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
	lrbp->sense_buffer = cmd->sense_buffer;
	lrbp->task_tag = tag;
	lrbp->lun = cmd->device->lun;

	if (ufshcd_is_query_req(lrbp))
		lrbp->command_type = UTP_CMD_TYPE_DEV_MANAGE;
	else
		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)
		goto out;

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

/**
 *  ufshcd_query_request() - Entry point for issuing query request to a
 *  ufs device.
 *  @hba: ufs driver context
 *  @query: params for query request
 *  @descriptor: buffer for sending/receiving descriptor
 *  @response: pointer to a buffer that will contain the response code and
 *           response upiu
 *  @timeout: time limit for the command in seconds
 *  @retries: number of times to try executing the command
 *
 *  The query request is submitted to the same request queue as the rest of
 *  the scsi commands passed to the UFS controller. In order to use this
 *  queue, we need to receive a tag, same as all other commands. The tags
 *  are issued from the block layer. To simulate a request from the block
 *  layer, we use the same interface as the SCSI layer does when it issues
 *  commands not generated by users. To distinguish a query request from
 *  the SCSI commands, we use a vendor specific unused SCSI command
 *  op-code. This op-code is not part of the SCSI command subset used in
 *  UFS. In such way it is easy to check the command in the driver and
 *  handle it appropriately.
 *
 *  All necessary fields for issuing a query and receiving its response are
 *  stored in the UFS hba struct. We can use this method since we know
 *  there is only one active query request at all times.
 *
 *  The request that will pass to the device is stored in "query" argument
 *  passed to this function, while the "response" argument (which is output
 *  field) will hold the query response from the device along with the
 *  response code.
 */
int ufshcd_query_request(struct ufs_hba *hba,
			struct ufs_query_req *query,
			u8 *descriptor,
			struct ufs_query_res *response,
			int timeout,
			int retries)
{
	struct scsi_device *sdev;
	u8 cmd[UFS_QUERY_CMD_SIZE] = {0};
	int result;
	bool sdev_lookup = true;

	if (!hba || !query || !response) {
		pr_err("%s: NULL pointer hba = %p, query = %p response = %p\n",
			__func__, hba, query, response);
		return -EINVAL;
	}

	/*
	 * A SCSI command structure is composed from opcode at the
	 * begining and 0 at the end.
	 */
	cmd[0] = UFS_QUERY_RESERVED_SCSI_CMD;

	/* extracting the SCSI Device */
	sdev = scsi_device_lookup(hba->host, 0, 0, 0);
	if (!sdev) {
		/**
		 * There are some Query Requests that are sent during device
		 * initialization, this happens before the scsi device was
		 * initialized. If there is no scsi device, we generate a
		 * temporary device to allow the Query Request flow.
		 */
		sdev_lookup = false;
		sdev = scsi_get_host_dev(hba->host);
	}

	if (!sdev) {
		dev_err(hba->dev, "%s: Could not fetch scsi device\n",
			__func__);
		return -ENODEV;
	}

	mutex_lock(&hba->query.lock_ufs_query);
	hba->query.request = query;
	hba->query.descriptor = descriptor;
	hba->query.response = response;

	/* wait until request is completed */
	result = scsi_execute(sdev, cmd, DMA_NONE, NULL, 0, NULL,
				timeout, retries, 0, NULL);
	if (result) {
		dev_err(hba->dev,
			"%s: Query with opcode 0x%x, failed with result %d\n",
			__func__, query->upiu_req.opcode, result);
		result = -EIO;
	}

	hba->query.request = NULL;
	hba->query.descriptor = NULL;
	hba->query.response = NULL;
	mutex_unlock(&hba->query.lock_ufs_query);

	/* Releasing scsi device resource */
	if (sdev_lookup)
		scsi_device_put(sdev);
	else
		scsi_free_host_dev(sdev);

	return result;
}

/**
 * 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 = dma_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 = dma_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 = dma_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 = kcalloc(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:
	ufshcd_free_hba_memory(hba);
	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);

		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;
	unsigned long flags;

	/* check if controller is ready to accept UIC commands */
	if (((readl(hba->mmio_base + REG_CONTROLLER_STATUS)) &
	    UIC_COMMAND_READY) == 0x0) {
		dev_err(hba->dev,
			"Controller not ready"
			" to accept UIC commands\n");
		return -EIO;
	}

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

	/* form UIC command */
	uic_cmd = &hba->active_uic_cmd;
	uic_cmd->command = UIC_CMD_DME_LINK_STARTUP;
	uic_cmd->argument1 = 0;
	uic_cmd->argument2 = 0;
	uic_cmd->argument3 = 0;

	/* enable UIC related interrupts */
	hba->int_enable_mask |= UIC_COMMAND_COMPL;
	ufshcd_int_config(hba, UFSHCD_INT_ENABLE);

	/* sending UIC commands to controller */
	ufshcd_send_uic_command(hba, uic_cmd);
	spin_unlock_irqrestore(hba->host->host_lock, flags);
	return 0;
}

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

	/* check if device present */
	reg = readl((hba->mmio_base + REG_CONTROLLER_STATUS));
	if (!ufshcd_is_device_present(reg)) {
		dev_err(hba->dev, "cc: Device not present\n");
		err = -ENXIO;
		goto out;
	}

	/*
	 * UCRDY, UTMRLDY and UTRLRDY bits must be 1
	 * DEI, HEI bits must be 0
	 */
	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;
	}

	/* Enable required interrupts */
	hba->int_enable_mask |= (UTP_TRANSFER_REQ_COMPL |
				 UIC_ERROR |
				 UTP_TASK_REQ_COMPL |
				 DEVICE_FATAL_ERROR |
				 CONTROLLER_FATAL_ERROR |
				 SYSTEM_BUS_FATAL_ERROR);
	ufshcd_int_config(hba, UFSHCD_INT_ENABLE);

	/* Configure interrupt aggregation */
	ufshcd_config_int_aggr(hba, INT_AGGR_CONFIG);

	if (hba->ufshcd_state == UFSHCD_STATE_RESET)
		scsi_unblock_requests(hba->host);

	hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
	scsi_scan_host(hba->host);
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);
	}

	/* 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);
	}
	return 0;
}

/**
 * ufshcd_initialize_hba - start the initialization process
 * @hba: per adapter instance
 *
 * 1. Enable the controller via ufshcd_hba_enable.
 * 2. Program the Transfer Request List Address with the starting address of
 * UTRDL.
 * 3. Program the Task Management Request List Address with starting address
 * of UTMRDL.
 *
 * Returns 0 on success, non-zero value on failure.
 */
static int ufshcd_initialize_hba(struct ufs_hba *hba)
{
	if (ufshcd_hba_enable(hba))
		return -EIO;

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

	/* Initialize unipro link startup procedure */
	return ufshcd_dme_link_startup(hba);
}

/**
 * ufshcd_do_reset - reset the host controller
 * @hba: per adapter instance
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_do_reset(struct ufs_hba *hba)
{
	struct ufshcd_lrb *lrbp;
	unsigned long flags;
	int tag;

	/* block commands from midlayer */
	scsi_block_requests(hba->host);

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

	/* send controller to reset state */
	ufshcd_hba_stop(hba);
	spin_unlock_irqrestore(hba->host->host_lock, flags);

	/* abort outstanding commands */
	for (tag = 0; tag < hba->nutrs; tag++) {
		if (test_bit(tag, &hba->outstanding_reqs)) {
			lrbp = &hba->lrb[tag];
			scsi_dma_unmap(lrbp->cmd);
			lrbp->cmd->result = DID_RESET << 16;
			lrbp->cmd->scsi_done(lrbp->cmd);
			lrbp->cmd = NULL;
		}
	}

	/* clear outstanding request/task bit maps */
	hba->outstanding_reqs = 0;
	hba->outstanding_tasks = 0;

	/* start the initialization process */
	if (ufshcd_initialize_hba(hba)) {
		dev_err(hba->dev,
			"Reset: Controller initialization failed\n");
		return FAILED;
	}
	return SUCCESS;
}

/**
 * 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);

	/*
	 * Inform SCSI Midlayer that the LUN queue depth is same as the
	 * controller queue depth. If a LUN queue depth is less than the
	 * controller queue depth and if the LUN reports
	 * SAM_STAT_TASK_SET_FULL, the LUN queue depth will be adjusted
	 * with scsi_adjust_queue_depth.
	 */
	scsi_activate_tcq(sdev, hba->nutrs);
	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);
}

/**
 * ufshcd_task_req_compl - handle task management request completion
 * @hba: per adapter instance
 * @index: index of the completed request
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index)
{
	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 (task_result != UPIU_TASK_MANAGEMENT_FUNC_COMPL &&
		    task_result != UPIU_TASK_MANAGEMENT_FUNC_SUCCEEDED)
			task_result = FAILED;
		else
			task_result = SUCCESS;
	} else {
		task_result = FAILED;
		dev_err(hba->dev,
			"trc: Invalid ocs = %x\n", ocs_value);
	}
	spin_unlock_irqrestore(hba->host->host_lock, flags);
	return task_result;
}

/**
 * ufshcd_adjust_lun_qdepth - Update LUN queue depth if device responds with
 *			      SAM_STAT_TASK_SET_FULL SCSI command status.
 * @cmd: pointer to SCSI command
 */
static void ufshcd_adjust_lun_qdepth(struct scsi_cmnd *cmd)
{
	struct ufs_hba *hba;
	int i;
	int lun_qdepth = 0;

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

	/*
	 * LUN queue depth can be obtained by counting outstanding commands
	 * on the LUN.
	 */
	for (i = 0; i < hba->nutrs; i++) {
		if (test_bit(i, &hba->outstanding_reqs)) {

			/*
			 * Check if the outstanding command belongs
			 * to the LUN which reported SAM_STAT_TASK_SET_FULL.
			 */
			if (cmd->device->lun == hba->lrb[i].lun)
				lun_qdepth++;
		}
	}

	/*
	 * LUN queue depth will be total outstanding commands, except the
	 * command for which the LUN reported SAM_STAT_TASK_SET_FULL.
	 */
	scsi_adjust_queue_depth(cmd->device, MSG_SIMPLE_TAG, lun_qdepth - 1);
}

/**
 * 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_GOOD:
		result |= DID_OK << 16 |
			  COMMAND_COMPLETE << 8 |
			  SAM_STAT_GOOD;
		break;
	case SAM_STAT_CHECK_CONDITION:
		result |= DID_OK << 16 |
			  COMMAND_COMPLETE << 8 |
			  SAM_STAT_CHECK_CONDITION;
		ufshcd_copy_sense_data(lrbp);
		break;
	case SAM_STAT_BUSY:
		result |= SAM_STAT_BUSY;
		break;
	case SAM_STAT_TASK_SET_FULL:

		/*
		 * If a LUN reports SAM_STAT_TASK_SET_FULL, then the LUN queue
		 * depth needs to be adjusted to the exact number of
		 * outstanding commands the LUN can handle at any given time.
		 */
		ufshcd_adjust_lun_qdepth(lrbp->cmd);
		result |= SAM_STAT_TASK_SET_FULL;
		break;
	case SAM_STAT_TASK_ABORTED:
		result |= SAM_STAT_TASK_ABORTED;
		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. In
 * case of query request specific result, returns DID_OK, and
 * the error will be handled by the dispatcher.
 */
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:
		/* check if the returned transfer response is valid */
		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);
			break;
		case UPIU_TRANSACTION_QUERY_RSP:
			/*
			 *  Return result = ok, since SCSI layer wouldn't
			 *  know how to handle errors from query requests.
			 *  The result is saved with the response so that
			 *  the ufs_core layer will handle it.
			 */
			result = DID_OK << 16;
			ufshcd_copy_query_response(hba, lrbp);
			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;
	case OCS_ABORTED:
		result |= DID_ABORT << 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_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 *lrb;
	unsigned long completed_reqs;
	u32 tr_doorbell;
	int result;
	int index;

	lrb = hba->lrb;
	tr_doorbell =
		readl(hba->mmio_base + REG_UTP_TRANSFER_REQ_DOOR_BELL);
	completed_reqs = tr_doorbell ^ hba->outstanding_reqs;

	for (index = 0; index < hba->nutrs; index++) {
		if (test_bit(index, &completed_reqs)) {

			result = ufshcd_transfer_rsp_status(hba, &lrb[index]);

			if (lrb[index].cmd) {
				scsi_dma_unmap(lrb[index].cmd);
				lrb[index].cmd->result = result;
				lrb[index].cmd->scsi_done(lrb[index].cmd);

				/* Mark completed command as NULL in LRB */
				lrb[index].cmd = NULL;
			}
		} /* end of if */
	} /* end of for */

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

	/* Reset interrupt aggregation counters */
	ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
}

/**
 * ufshcd_uic_cc_handler - handle UIC command completion
 * @work: pointer to a work queue structure
 *
 * Returns 0 on success, non-zero value on failure
 */
static void ufshcd_uic_cc_handler (struct work_struct *work)
{
	struct ufs_hba *hba;

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

	if ((hba->active_uic_cmd.command == UIC_CMD_DME_LINK_STARTUP) &&
	    !(ufshcd_get_uic_cmd_result(hba))) {

		if (ufshcd_make_hba_operational(hba))
			dev_err(hba->dev,
				"cc: hba not operational state\n");
		return;
	}
}

/**
 * ufshcd_fatal_err_handler - handle fatal errors
 * @hba: per adapter instance
 */
static void ufshcd_fatal_err_handler(struct work_struct *work)
{
	struct ufs_hba *hba;
	hba = container_of(work, struct ufs_hba, feh_workq);

	/* check if reset is already in progress */
	if (hba->ufshcd_state != UFSHCD_STATE_RESET)
		ufshcd_do_reset(hba);
}

/**
 * ufshcd_err_handler - Check for fatal errors
 * @work: pointer to a work queue structure
 */
static void ufshcd_err_handler(struct ufs_hba *hba)
{
	u32 reg;

	if (hba->errors & INT_FATAL_ERRORS)
		goto fatal_eh;

	if (hba->errors & UIC_ERROR) {

		reg = readl(hba->mmio_base +
			    REG_UIC_ERROR_CODE_PHY_ADAPTER_LAYER);
		if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
			goto fatal_eh;
	}
	return;
fatal_eh:
	hba->ufshcd_state = UFSHCD_STATE_ERROR;
	schedule_work(&hba->feh_workq);
}

/**
 * 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 = readl(hba->mmio_base + REG_UTP_TASK_REQ_DOOR_BELL);
	hba->tm_condition = tm_doorbell ^ hba->outstanding_tasks;
	wake_up_interruptible(&hba->ufshcd_tm_wait_queue);
}

/**
 * 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_err_handler(hba);

	if (intr_status & UIC_COMMAND_COMPL)
		schedule_work(&hba->uic_workq);

	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 = readl(hba->mmio_base + REG_INTERRUPT_STATUS);

	if (intr_status) {
		ufshcd_sl_intr(hba, intr_status);

		/* If UFSHCI 1.0 then clear interrupt status register */
		if (hba->ufs_version == UFSHCI_VERSION_10)
			writel(intr_status,
			       (hba->mmio_base + REG_INTERRUPT_STATUS));
		retval = IRQ_HANDLED;
	}
	spin_unlock(hba->host->host_lock);
	return retval;
}

/**
 * ufshcd_issue_tm_cmd - issues task management commands to controller
 * @hba: per adapter instance
 * @lrbp: pointer to local reference block
 *
 * Returns SUCCESS/FAILED
 */
static int
ufshcd_issue_tm_cmd(struct ufs_hba *hba,
		    struct ufshcd_lrb *lrbp,
		    u8 tm_function)
{
	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 = 0;
	int err;

	host = hba->host;

	spin_lock_irqsave(host->host_lock, flags);

	/* If task management queue is full */
	free_slot = ufshcd_get_tm_free_slot(hba);
	if (free_slot >= hba->nutmrs) {
		spin_unlock_irqrestore(host->host_lock, flags);
		dev_err(hba->dev, "Task management queue full\n");
		err = FAILED;
		goto out;
	}

	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_req_upiup->header.dword_0 =
		UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
					      lrbp->lun, lrbp->task_tag);
	task_req_upiup->header.dword_1 =
		UPIU_HEADER_DWORD(0, tm_function, 0, 0);

	task_req_upiup->input_param1 = lrbp->lun;
	task_req_upiup->input_param1 =
		cpu_to_be32(task_req_upiup->input_param1);
	task_req_upiup->input_param2 = lrbp->task_tag;
	task_req_upiup->input_param2 =
		cpu_to_be32(task_req_upiup->input_param2);

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

	spin_unlock_irqrestore(host->host_lock, flags);

	/* wait until the task management command is completed */
	err =
	wait_event_interruptible_timeout(hba->ufshcd_tm_wait_queue,
					 (test_bit(free_slot,
					 &hba->tm_condition) != 0),
					 60 * HZ);
	if (!err) {
		dev_err(hba->dev,
			"Task management command timed-out\n");
		err = FAILED;
		goto out;
	}
	clear_bit(free_slot, &hba->tm_condition);
	err = ufshcd_task_req_compl(hba, free_slot);
out:
	return err;
}

/**
 * ufshcd_device_reset - reset device and abort all the pending commands
 * @cmd: SCSI command pointer
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_device_reset(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *host;
	struct ufs_hba *hba;
	unsigned int tag;
	u32 pos;
	int err;

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

	err = ufshcd_issue_tm_cmd(hba, &hba->lrb[tag], UFS_LOGICAL_RESET);
	if (err == FAILED)
		goto out;

	for (pos = 0; pos < hba->nutrs; pos++) {
		if (test_bit(pos, &hba->outstanding_reqs) &&
		    (hba->lrb[tag].lun == hba->lrb[pos].lun)) {

			/* clear the respective UTRLCLR register bit */
			ufshcd_utrl_clear(hba, pos);

			clear_bit(pos, &hba->outstanding_reqs);

			if (hba->lrb[pos].cmd) {
				scsi_dma_unmap(hba->lrb[pos].cmd);
				hba->lrb[pos].cmd->result =
						DID_ABORT << 16;
				hba->lrb[pos].cmd->scsi_done(cmd);
				hba->lrb[pos].cmd = NULL;
			}
		}
	} /* end of for */
out:
	return err;
}

/**
 * ufshcd_host_reset - Main reset function registered with scsi layer
 * @cmd: SCSI command pointer
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_host_reset(struct scsi_cmnd *cmd)
{
	struct ufs_hba *hba;

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

	if (hba->ufshcd_state == UFSHCD_STATE_RESET)
		return SUCCESS;

	return ufshcd_do_reset(hba);
}

/**
 * ufshcd_abort - abort a specific command
 * @cmd: SCSI command pointer
 *
 * 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;

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

	spin_lock_irqsave(host->host_lock, flags);

	/* check if command is still pending */
	if (!(test_bit(tag, &hba->outstanding_reqs))) {
		err = FAILED;
		spin_unlock_irqrestore(host->host_lock, flags);
		goto out;
	}
	spin_unlock_irqrestore(host->host_lock, flags);

	err = ufshcd_issue_tm_cmd(hba, &hba->lrb[tag], UFS_ABORT_TASK);
	if (err == FAILED)
		goto out;

	scsi_dma_unmap(cmd);

	spin_lock_irqsave(host->host_lock, flags);

	/* clear the respective UTRLCLR register bit */
	ufshcd_utrl_clear(hba, tag);

	__clear_bit(tag, &hba->outstanding_reqs);
	hba->lrb[tag].cmd = NULL;
	spin_unlock_irqrestore(host->host_lock, flags);
out:
	return err;
}

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_destroy		= ufshcd_slave_destroy,
	.eh_abort_handler	= ufshcd_abort,
	.eh_device_reset_handler = ufshcd_device_reset,
	.eh_host_reset_handler	= ufshcd_host_reset,
	.this_id		= -1,
	.sg_tablesize		= SG_ALL,
	.cmd_per_lun		= UFSHCD_CMD_PER_LUN,
	.can_queue		= UFSHCD_CAN_QUEUE,
};

/**
 * ufshcd_suspend - suspend power management function
 * @hba: per adapter instance
 * @state: power state
 *
 * Returns -ENOSYS
 */
int ufshcd_suspend(struct ufs_hba *hba, pm_message_t state)
{
	/*
	 * TODO:
	 * 1. Block SCSI requests from SCSI midlayer
	 * 2. Change the internal driver state to non operational
	 * 3. Set UTRLRSR and UTMRLRSR bits to zero
	 * 4. Wait until outstanding commands are completed
	 * 5. Set HCE to zero to send the UFS host controller to reset state
	 */

	return -ENOSYS;
}
EXPORT_SYMBOL_GPL(ufshcd_suspend);

/**
 * ufshcd_resume - resume power management function
 * @hba: per adapter instance
 *
 * Returns -ENOSYS
 */
int ufshcd_resume(struct ufs_hba *hba)
{
	/*
	 * TODO:
	 * 1. Set HCE to 1, to start the UFS host controller
	 * initialization process
	 * 2. Set UTRLRSR and UTMRLRSR bits to 1
	 * 3. Change the internal driver state to operational
	 * 4. Unblock SCSI requests from SCSI midlayer
	 */

	return -ENOSYS;
}
EXPORT_SYMBOL_GPL(ufshcd_resume);

/**
 * ufshcd_hba_free - free allocated memory for
 *			host memory space data structures
 * @hba: per adapter instance
 */
static void ufshcd_hba_free(struct ufs_hba *hba)
{
	iounmap(hba->mmio_base);
	ufshcd_free_hba_memory(hba);
}

/**
 * ufshcd_remove - de-allocate SCSI host and host memory space
 *		data structure memory
 * @hba - per adapter instance
 */
void ufshcd_remove(struct ufs_hba *hba)
{
	/* disable interrupts */
	ufshcd_int_config(hba, UFSHCD_INT_DISABLE);

	ufshcd_hba_stop(hba);
	ufshcd_hba_free(hba);

	scsi_remove_host(hba->host);
	scsi_host_put(hba->host);
}
EXPORT_SYMBOL_GPL(ufshcd_remove);

/**
 * ufshcd_init - Driver initialization routine
 * @dev: pointer to device handle
 * @hba_handle: driver private handle
 * @mmio_base: base register address
 * @irq: Interrupt line of device
 * Returns 0 on success, non-zero value on failure
 */
int ufshcd_init(struct device *dev, struct ufs_hba **hba_handle,
		 void __iomem *mmio_base, unsigned int irq)
{
	struct Scsi_Host *host;
	struct ufs_hba *hba;
	int err;

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

	if (!mmio_base) {
		dev_err(dev,
		"Invalid memory reference for mmio_base 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->mmio_base = mmio_base;
	hba->irq = irq;

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

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

	/* 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 = UFSHCD_MAX_LUNS;
	host->max_channel = UFSHCD_MAX_CHANNEL;
	host->unique_id = host->host_no;
	host->max_cmd_len = MAX_CDB_SIZE;

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

	/* Initialize work queues */
	INIT_WORK(&hba->uic_workq, ufshcd_uic_cc_handler);
	INIT_WORK(&hba->feh_workq, ufshcd_fatal_err_handler);

	/* Initialize mutex for query requests */
	mutex_init(&hba->query.lock_ufs_query);

	/* IRQ registration */
	err = request_irq(irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
	if (err) {
		dev_err(hba->dev, "request irq failed\n");
		goto out_lrb_free;
	}

	/* 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 out_free_irq;
	}

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

	/* Initialization routine */
	err = ufshcd_initialize_hba(hba);
	if (err) {
		dev_err(hba->dev, "Initialization failed\n");
		goto out_remove_scsi_host;
	}
	*hba_handle = hba;

	return 0;

out_remove_scsi_host:
	scsi_remove_host(hba->host);
out_free_irq:
	free_irq(irq, hba);
out_lrb_free:
	ufshcd_free_hba_memory(hba);
out_disable:
	scsi_host_put(host);
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);